Note: Descriptions are shown in the official language in which they were submitted.
METHOD AND SYSTEM FOR PRODUCING POTASSIUM CHLORIDE
BY RECYCLING BYPRODUCTS
FIELD
[0001] Embodiments of the present disclosure generally relate to field of
producing
potassium chloride, and more particularly relate to a method and system for
producing
potassium chloride by recycling byproducts.
BACKGROUND
[0002]
Conventional potassium chloride producing methods using salt lake brine mainly
include: a cold crystallization - direct flotation process, a hot soluble-
crystallization process,
a reverse flotation - cold crystallization process, and a brine mixing process
and the like, or a
combination of any of the processes above. The reverse flotation-cold
crystallization process
is applied relatively extensively. However, this process has a quality
requirement on the raw
carnallite and prefers using the salt pan carnallite ore, thereby requiring a
large investment
and a high energy consumption. However, the grade of final potassium chloride
product using
this process can only reach about 95%.
[0003] Meanwhile, during the whole production process, the potassium chloride
contained
in byproducts fails to be well recycled. This causes a large amount of
potassium chloride to
be discharged with tailings, thereby wasting potassium resources.
[0004] Further, if one device in the whole production line fails, material
accumulation can
occur. A more serious consequence is a full line shut-down and overhaul. This
can reduce the
line's productivity.
[0005] Therefore, it is desirable to further improve relevant production
systems and process
methods so as to extract potassium chloride from the byproducts of potash
fertilizer
production by combining an intra-system utilization approach and an outside-of-
system
utilization approach, thereby increasing the yield and efficiency of potash
fertilizer
production, and additionally, by improving connection manners and combination
manners
of various devices, a continuous production is easy to maintain, such that the
overall process
will not be
1
Date Recue/Date Received 2021-04-14
affected by failure of any individual devices.
SUMMARY
[0006] A technical problem to be solved by the present disclosure is to
provide a method and
system for producing potassium chloride by recycling byproducts.
[0007] The present disclosure provides a system for producing potassium
chloride by
recycling byproducts. The system comprises: a run-of-mine treatment system 1,
a pulp
conditioning system 2, a flotation system 3, a low sodium concentration and
brine removal
system 4, a cold crystallization and crude potassium screening system 5, a
crude potassium
concentration and brine removal system 6, a refined potassium washing and
brine removal
system 7, and an overflow liquid and filtrate treatment system 8. The run-of-
mine treatment
system 1 is configured to screen and concentrate a carnallite pulp to obtain a
first undertlow
slurry and a first overflow liquid; the pulp conditioning system 2, which is
connected to the
run-of-mine treatment system 1, is configured to mix a flotation reagent with
the first
undertlow slurry to obtain a pulp conditioned slurry; the flotation system 3
is configured to
perform a flotation operation on the pulp conditioned slurry to obtain
tailings and a
low-sodium carnallite slurry, the low-sodium concentration and brine removal
system 4,
which is connected to the flotation system 3, is configured to concentrate and
remove brine
from the low-sodium carnallite slurry to obtain a second overflow liquid, a
first filtrate, and a
low-sodium carnallite ore with a <10% content of moisture; the cold
crystallization and crude
potassium screening system 5, which is connected to the low-sodium
concentration and brine
removal system 4, is configured to decompose crystallize, and screen the low-
sodium
carnallite ore with a <10% content of moisture to obtain a third overflow
liquid, a crude
potassium screen overflow, and a crude potassium screen undertlow; the crude
potassium
concentration and brine removal system 6, which is connected to the cold
crystallization and
crude potassium screening system 5, is configured to concentrate and remove
brine from the
crude potassium screen underflow to obtain a fourth overflow liquid, a second
filtrate, and a
crude potassium ore with a <10% content of moisture; the refined potassium
washing and
brine removal system 7, which is connected to the crude potassium
concentration and brine
removal system 6, is configured to wash and remove brine from the crude
potassium ore with
a <10% content of moisture to obtain a third filtrate and a refined potassium
ore; and the
overflow liquid and filtrate treatment system 8 is configured to recover and
treat the first
overflow liquid, the third overflow liquid, the fifth overflow liquid, and the
first filtrate.
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[0008] According to an embodiment of the present disclosure, the overflow
liquid and
filtrate treatment system 8 comprises a first treatment system 81, a second
treatment system
82, and a third treatment system 83, wherein the first treatment system 81,
which is
respectively connected to the run-of-mine treatment system 1 and the flotation
system 3, is
configured to receive the first overflow liquid from the run-of-mine treatment
system 1 and
receive the floatation tailings from the flotation system 3, wherein the first
overflow liquid
and the flotation tailings are subjected to pulp conditioning and then
discharged; the second
treatment system 82, which is respectively connected to the cold
crystallization and crude
potassium screening system 5 and the refined potassium washing and brine
removal system 7.
is configured to receive the third overflow liquid from the cold
crystallization and crude
potassium screening system 5 and receive the fifth overflow liquid from the
refined potassium
washing and brine removal system 7, wherein the third overflow liquid and the
fifth overflow
liquid, after being conditioned with fresh water, are transferred to the cold
crystallization and
crude potassium screening system 5 as a decomposing mother liquor; and the
third treatment
system 83, which is connected to the low-sodium concentration and brine
removal system 4,
is configured to receive, concentrate, and filter the first filtrate to
recover the carnallite.
[0009] According to an embodiment of the present disclosure, the first
treatment system 81
further comprises a primary scavenging cell 811, a secondary scavenging cell
812, and a
storage tank 813, wherein the primary scavenging cell 811, when connected to
the flotation
system, is configured to receive the floatation tailings and perform primary
scavenging to
obtain a primarily scavenged froth and a primarily scavenged underflow; the
secondary
scavenging cell 812, when connected to the primary scavenging cell 811, is
configured to
receive the primarily scavenged underflow and performing secondary scavenging
to obtain a
secondarily scavenged froth and a secondarily scavenged undertlow; the primary
scavenged
cell 811, when connected to a tailing pond, is configured tor transfer the
primary scavenged
froth to the tailing pond; the secondary scavenging cell 812, when connected
to the storage
tank 813, is configured to transfer the secondarily scavenged underflow to the
storage tank
813; and the secondary scavenging cell 812, when connected to the low sodium
concentration
and brine removal system 4, is configured to transfer the secondarily
scavenged underflow to
the low sodium concentration and brine removal system 4.
[0010] According to an embodiment of the present disclosure, the low sodium
concentration
and brine removal system 4, which is connected to the flotation system 3, is
configured
totransfer the second overflow liquid to the flotation system 3 so as to
adjust a concentration
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of the pulp conditioned slurry.
[0011] According to an embodiment of the present disclosure, the crude
potassium
concentration and brine removal system 6, which is connected to the run-of-
mine treatment
system 1, is configured to transfer the fourth overflow liquid to the run-of-
mine treatment
system 1 so as to be concentrated for utilization.
[0012] According to an embodiment of the present disclosure, the run-of-mine
treatment
system 1 comprises a carnallite screening machine 11 and a run-of-mine
concentrator 12,
wherein the carnallite screening machine 11 is configured for screening off
impurities and
large-particle salt in the carnallite pulp to obtain a screen underflow
product; and the
run-of-mine concentrator 12, which is connected to the carnallite screening
machine 11, is
configured for concentration the screen underflow product to obtain the first
overflow liquid
and the first underflow slurry, causing a solid mass content of the first
underflow slurry to be
30-45%, wherein the run-of-mine concentrator 12 is provided in one or in
plurality.
100131 According to an embodiment of the present disclosure, the pulp
conditioning system
2 comprises a slurry distribution tray 21 and a pulp conditioning tank 22,
wherein the slurry
distribution tray 21 comprises a plurality of interfaces for connecting with
the plurality of
run-of-mine concentrators 12, the slurry distribution tray 21 being configured
to receive the
first underflow slurry, mix the first undertlow slurry with the flotation
reagent, and distribute
the first underflow slurry and the flotation reagent to the pulp conditioning
tank 22; and the
pulp conditioning tank 22, which is connected to the slurry distribution tray
21, is configured
to uniformly mix the first undertlow slurry and the flotation reagent to
obtain the pulp
conditioned slurry.
[0014] According to an embodiment of the present disclosure, the flotation
system 3
comprises a flotation distribution tray 31 and a flotation machine 32, wherein
the flotation
distribution tray 31, which is connected to the pulp conditioning system 2, is
configured to
receive the pulp conditioned slurry, and perform concentration adjustment to
the pulp
conditioned slurry by adding an adjustment mother liquor to obtain an adjusted
slurry,
wherein a solid mass content of the adjusted slurry is 20 /0-25%, and the
adjustment mother
liquor refers to a liquid phase having same compositions as a slurry mother
liquor; and the
flotation machine 32, which is connected to the flotation distribution tray
31, is configured to
perform roughing, concentrating, and scavenging operations on the adjusted
slurry to obtain
the tailings and the low-sodium carnallite slurry, wherein the flotation
machine 32 is provided
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in one or in plurality.
[0015] According to an embodiment of the present disclosure, the low-sodium
concentration
and brine removal system 4 comprises a low-sodium concentrator 41, a low-
sodium
centrifugal machine distribution tank 42, and a low-sodium centrifugal machine
43, wherein
the low-sodium concentrator 41 is configured to receive the low-sodium
carnallite slurry and
concentrate the low-sodium carnallite slurry to obtain the second undertlow
slurry and the
second overflow liquid, wherein a solid mass content of the second underflow
slurry is
40%-45%; the low-sodium concentrator 41 is provided in one or in plurality:
the low-sodium
centrifugal machine distribution tank 42, which is connected to the low-sodium
concentrator
41. is configured to receive and distribute the second underflow slurry to the
low-sodium
centrifugal machine 43; the low-sodium centrifugal machine 43, which is
provided in one or
in plurality and connected to the low-sodium centrifugal machine distribution
tank 42, is
configured for remove brine from the second underflow slurry to obtain the
first filtrate and
the low-sodium carnallite ore with a <10% content of moisture.
[0016] According to an embodiment of the present disclosure, the cold
crystallization and
crude potassium screening system 5 comprises a crystallizer 51 and a crude
potassium
screening machine 52, wherein the crystallizer 51, which is provided in one or
in plurality, is
configured to receive, decompose, and crystallize the low-sodium carnallite
ore with a <10%
content of moisture to obtain the third underflow slurry and the third
overflow liquid, wherein
a solid mass content of the third underflow slurry is 15% ¨ 30%; and the crude
potassium
screening machine 52, which is connected to the crystallizer 51, is configured
to screen the
third underflow slurry to obtain the crude potassium screen overflow and the
crude potassium
screen undertlow.
[0017] According to an embodiment of the present disclosure, the crude
potassium
concentration and brine removal system 6 comprises a crude potassium
concentrator 61, a
crude potassium centrifugal machine distribution tank 62, and a crude
potassium centrifugal
machine 63, wherein the crude potassium concentrator 61, which is provided in
one or in
plurality, is configured to receive and concentrate the crude potassium screen
undertlow to
obtain the fourth overflow liquid and the fourth underflow slurry, wherein a
solid mass
content of the fourth undertlow slurry is 40%-45%; the crude potassium
centrifugal machine
distribution tank 62, which is connected to the crude potassium concentrator
61, is configured
to receive and distribute the fourth undertlow slurry to respective crude
potassium centrifugal
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machines 63; the crude potassium centrifugal machine 63, which is provided in
one or in
plurality and connected to the crude potassium centrifugal machine
distribution tank 62, is
configured to remove brine from the fourth underflow slurry to obtain the
second filtrate and
the crude potassium ore with a <10% content of moisture.
[0018] According to an embodiment of the present disclosure, the crude
potassium
centrifugal machine 63, which is connected to the crude potassium concentrator
61, is
configured to transfer the second filtrate to the crude potassium concentrator
61 so as to be
recycled.
[0019] According to an embodiment of the present disclosure, the refined
potassium
washing and brine removal system 7 comprises a repulp washing tank 71, a
refined potassium
concentrator 72, and a refined potassium centrifugal machine 73, wherein the
repulp washing
tank 71, which is provided in one or in plurality, is configured to receive
and wash the crude
potassium ore with a <10% content of moisture to obtain a repulpped slurry;
the refined
potassium concentrator 72, which is provided in one or in plurality and
corresponds to the
repulp washing tank 71, is configured to concentrate the repulpped slurry to
obtain the fifth
undertlow slurry; the refined potassium centrifugal machine 73, which is
provided in one or
in plurality and matched to the refined potassium concentrator 72, is
configured to remove
brine from the fifth underflow slurry to obtain the refined potassium ore and
the third filtrate,
wherein the refined potassium ore has a <10% content of moisture.
[0020] According to an embodiment of the present disclosure, the refined
potassium
concentrator 72. which is connected to the repulp washing tank, is configured
to condition a
concentration of the crude potassium ore with a <10% content of moisture using
the fifth
underflow slurry. The refined potassium concentrator 72, which is connected to
the refined
potassium centrifugal machine 73, is configured to recover the third filtrate
to the refined
potassium concentrator 72 so as to be concentrated.
[0021] In another aspect of the present disclosure, a method for producing
potassium
chloride by recycling byproducts is provided. The method comprises: step SI:
screening and
concentrating a carnallite pulp to obtain a first undertlow slurry and a first
overflow liquid;
step S2: mixing a flotation reagent with the first undertlow slurry to obtain
a pulp conditioned
slurry; step S3: performing a flotation operation on the pulp conditioned
slurry to obtain
tailings and a low-sodium carnallite slurry; step S4: concentrating and
removing brine from
the low-sodium carnallite slurry to obtain a second overflow liquid, a first
filtrate, and a
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low-sodium carnallite ore with a <10% content of moisture; step S5:
decomposing,
crystallizing, and screening the low-sodium carnallite ore with a <10% content
of moisture to
obtain a third overflow liquid, a crude potassium screen overflow, and a crude
potassium
screen underflow; step S6: concentrating and removing brine from the crude
potassium screen
underflow to obtain a fourth overflow liquid, a second filtrate, and a crude
potassium ore with
a <10% content of moisture; step S7: washing and removing brine from the crude
potassium
ore with a <10% content of moisture to obtain a third filtrate and a refined
potassium ore; and
step S8: recovering and treating the first overflow liquid, the third overflow
liquid, the fifth
overflow liquid, and the first filtrate.
100221 According to an embodiment of the present disclosure, the step S8
comprises:
performing pulp conditioning to the first overflow liquid and the flotation
tailings and then
discharging the pulp conditioned first overflow liquid and flotation tailings;
receiving the
third overflow liquid and the fifth overflow liquid, which; after being
conditioned by fresh
water, are used as a decomposing mother liquor for a crystallization process;
receiving,
concentrating, and filtering the first filtrate to recover carnallite.
[0023] According to an embodiment of the present disclosure, the method
further comprises
performing primary scavenging to the flotation tailings to obtain a primarily
scavenged froth
and a primarily scavenged undertlow; performing secondary scavenging to the
primarily
scavenged underflow to obtain a secondarily scavenged froth and a secondarily
scavenged
underflow; performing pulp conditioning to the primarily scavenged froth and
the first
overflow liquid and then transferring the pulp conditioned primarily scavenged
froth and first
overflow liquid to a tailing pond; and transferring the secondarily scavenged
underflow to a
low-sodium concentration and brine removal system.
[0024] According to an embodiment of the present disclosure, the second
overflow liquid is
used to adjust a concentration of the pulp conditioned slurry.
[0025] According to an embodiment of the present disclosure, the fourth
overflow liquid is
used to blend the carnallite pulp.
[0026] According to an embodiment of the present disclosure, the step SI
comprises:
screening off impurities and large-particle salt in the carnallite pulp to
obtain a screen
underflow product; and concentrating the screen underflow product to obtain
the first
overflow liquid and the first underflow slurry, wherein a solid mass content
of the first
undertlow slurry is 30-45%, and a solid mass content of the carnallite pulp is
>25%.
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[0027] According to an embodiment of the present disclosure, the step S2
comprises: mixing
the first undertlow slurry with the flotation reagent. and distributing the
first undertlow slurry
and the flotation reagent; and uniformly mixing the first underflow slurry and
the flotation
reagent to obtain a pulp conditioned slurry.
[0028] According to an embodiment of the present disclosure, the step S3
comprises:
performing concentration adjustment to the pulp conditioned slurry by adding
an adjustment
mother liquor to obtain an adjusted slurry, wherein a solid mass content of
the adjusted slurry
is 20%-25%, and the adjustment mother liquor refers to a liquid phase having
same
compositions as a slurry mother liquor; and performing roughing,
concentrating, and
scavenging operations on the adjusted slurry to obtain the tailings and the
low-sodium
carnallite slurry.
[0029] According to an embodiment of the present disclosure, the step S4
comprises:
concentrating the low-sodium carnallite slurry to obtain the second undertlow
slurry and the
second overflow liquid, wherein a solid mass content of the second underflow
slurry is
40%-45%; distributing the second underflow slurry; removing brine from the
second
undertlow slurry to obtain the first filtrate and the low-sodium carnallite
ore with a <10%
content of moisture.
[0030] According to an embodiment of the present disclosure, the step S5
comprises: mixing
the low-sodium carnallite ore with a <10% content of moisture with a
decomposing mother
liquor to perform decomposition and crystallization under a controlled speed
to thereby obtain
the third undertlow slurry and the third overflow liquid, wherein a solid mass
content of the
third undertlow slurry is 15% ¨ 30%; and performing a screening operation on
the third
underflow slurry to obtain the crude potassium screen overflow and the crude
potassium
screen undertlow.
[0031] According to an embodiment of the present disclosure, the step S6
comprises:
concentrating the crude potassium screen undertlow to obtain the fourth
overflow liquid and
the fourth underflow slurry, wherein a solid mass content of the fourth
underflow slurry is
40%-45%; distributing the fourth underflow slurry; removing brine from the
fourth
underflow slurry to obtain the second filtrate and the crude potassium ore
with a <10%
content of moisture.
[0032] According to an embodiment of the present disclosure, the second
filtrate is
transferred to a procedure of concentrating the crude potassium screen
underflow to be
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recycled.
[0033] According to an embodiment of the present disclosure, the step S7
comprises:
washing the crude potassium ore with a <10% content of moisture to obtain a
repulpped slurry;
concentrating the repulpped slurry to obtain the fifth underflow slurry;
removing brine from
the fifth undertlow slurry to obtain the refined potassium ore and the third
filtrate, wherein the
refined potassium ore has a <10% content of moisture.
[00341] According to an embodiment of the present disclosure, in a repulp
procedure, a
concentration of the crude potassium ore with a <10% content of moisture is
adjusted using
the fifth underflow slurry; and the third filtrate is recovered to a repulpped
slurry
concentration procedure so as to be concentrated.
[0035] In the present disclosure, by recycling the first overflow liquid, the
third overflow
liquid, the fifth overflow liquid, and the first filtrate to the system
respectively, intra-system
recovery of potassium chloride is implemented to replace adding external
materials, which, on
one hand, increases the yield of potassium chloride, and on the other hand,
saves costs. In the
present disclosure, by parallel connecting the devices such as the run-of-mine
concentrator 12,
the flotation machine 32, and the low-sodium concentrator 41 and by uniform
pulp
conditioning with the pulp conditioning tank 22 and scattered distribution,
the treated
concentration of the material is made uniform; besides, due to the mutual
standby relationship
among the parallel-connected devices, failure or overhaul of one device does
not affect
operation of the overall process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] Fig. 1 is a schematic diagram of a system for producing potassium
chloride by
recycling byproducts according to one embodiment of the present disclosure;
100371 Fig. 2 is a schematic diagram of an overflow liquid and filtrate
treatment system
according to one embodiment of the present disclosure;
[0038] Fig. 3 is a schematic diagram of the first treatment system according
to one
embodiment of the present disclosure;
[0039] Fig. 4 is a schematic diagram of a run-of-mine treatment system
according to one
embodiment of the present disclosure;
100401 Fig. 5 is a schematic diagram of a pulp conditioning system according
to one
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CA 3053055 2019-08-26
embodiment of the present disclosure;
[0041] Fig. 6 is a schematic diagram of a flotation system according to one
embodiment of
the present disclosure;
[0042] Fig. 7 is a schematic diagram of a low-sodium concentration and brine
removal
system according to one embodiment of the present disclosure;
[0043] Fig. 8 is a schematic diagram of a cold crystallization and crude
potassium screening
system according to one embodiment of the present disclosure;
[0044] Fig. 9 is a schematic diagram of a crude potassium concentration and
brine removal
system according to one embodiment of the present disclosure;
[0045] Fig. 10 is a schematic diagram of a refined potassium washing and brine
removal
system according to one embodiment of the present disclosure; and
[0046] Fig. 11 is a schematic diagram showing steps of a method for producing
potassium
chloride by recycling byproducts according to one embodiment of the present
disclosure.
DETAILED DESCRIPTION OF EMBODIMENTS
[0047] Hereinafter, preferred embodiments of the present disclosure will be
illustrated in
detail with reference to the accompanying drawings; the reference numerals
represent
compositions and technologies in the present disclosure, such that
implementation of the
advantages and features of the present disclosure is more easily understood in
an appropriate
environment. What will be described hereinafter are specific implementations
of the claims of
the present disclosure, and other specific implementations which are related
to the claims but
not explicitly described also fall into the scope of the claims.
[0048] Fig. 1 is a schematic diagram of a system for producing potassium
chloride by
recycling byproducts in accordance with one embodiment of the present
disclosure.
[0049] As shown in Fig. I, a byproduct-recyclable system for producing
potassium chloride
comprises: a run-of-mine treatment system 1, a pulp conditioning system 2, a
flotation system
3, a low-sodium concentration and brine removal system 4, a cold
crystallization and crude
potassium screening system 5, a crude potassium concentration and brine
removal system 6, a
refined potassium washing and brine removal system 7, and an overflow liquid
and filtrate
treatment system 8, wherein the run-of-mine treatment system 1 is configured
to screen and
concentrate a camallite pulp to obtain a first underflow slurry and a first
overflow liquid; the
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pulp conditioning system 2, which is connected to the run-of-mine treatment
system 1, is
configured to mix a flotation reagent with the first underflow slurry to
obtain a pulp
conditioned slurry; the flotation system 3 is configured to perform a
flotation operation on the
pulp conditioned slurry to obtain tailings and a low-sodium carnallite slurry;
the low-sodium
concentration and brine removal system 4, which is connected to the flotation
system 3, is
configured to concentrate and remove brine from the low-sodium carnallite
slurry to obtain a
second overflow liquid, a first filtrate, and a low-sodium carnallite ore with
a <10% content of
moisture; the cold crystallization and crude potassium screening system 5,
which is connected
to the low-sodium concentration and brine removal system 4, is configured to
decompose,
crystallize, and screen the low-sodium carnallite ore with a <10% content of
moisture to
obtain a third overflow liquid, a crude potassium screen overflow, and a crude
potassium
screen underflow; the crude potassium concentration and brine removal system
6, which is
connected to the cold crystallization and crude potassium screening system 5,
is configured to
concentrate and remove brine from the crude potassium screen undertlow to
obtain a fourth
overflow liquid, a second filtrate, and a crude potassium ore with a10%
content of moisture;
the refined potassium washing and brine removal system 7, which is connected
to the crude
potassium concentration and brine removal system 6, is configured to wash and
remove brine
from the crude potassium ore with a <10% content of moisture to obtain a third
filtrate and a
refined potassium ore; and the overflow liquid and filtrate treatment system 8
is configured to
recover and treat the first overflow liquid, the third overflow liquid, the
fifth overflow liquid,
and the first filtrate.
100501 In the present disclosure, potassium chloride is produced with salt pan
carnallite as
the raw material. Main compositions of the collected salt pan carnallite
include: potassium
chloride, sodium chloride, and magnesium chloride. Concentration of carnallite
pulp is
adjusted to have a solid mass content >25%. Impurities, large-particle salt,
etc., are screened
off from the carnallite pulp by a carnallite screening machine 11; the screen
underflow is
transferred to the run-of-mine concentrator 12 to be concentrated to obtain
the first underflow
slurry and the first overflow liquid. By adjusting parameters of the
concentration device, a
solid mass content of the first undertlow slurry is adjusted to 30-45%.
100511 The first overflow liquid enters the overflow liquid and filtrate
treatment system 8 to
be treated.
100521 The first underflow slurry enters the pulp conditioning system 2,
wherein the
CA 3053055 2019-08-26
flotation reagent is added based on the solid mass content in the slurry; the
two are uniformly
mixed by agitating or other means known in the art to obtain a pulp
conditioned slurry.
[0053] By sufficiently and uniformly mixing the first undertlow slurry and the
flotation
reagent, the sodium flotation reagent may sufficiently contact with the sodium
chloride during
the flotation process, which can enhance flotation efficiency.
[0054] The present disclosure adopts a reverse flotation - cold
crystallization process,
wherein the flotation reagent is a sodium chloride collector. Before the pulp
conditioned
slurry enters the flotation device, its concentration needs to be adjusted to
yield a solid mass
content of 20%-25%, thereby further controlling the flotation efficiency.
[0055] During the reverse flotation process, the sodium chloride solid is
bonded with the
flotation reagent to form a froth, and the froth is discharged from the
flotation system 3 as
tailings; the low-sodium carnallite slurry is also obtained. Main compositions
of the
low-sodium carnallite slurry include: potassium chloride, magnesium chloride,
as well as a
small amount of sodium chloride.
[0056] The low-sodium carnallite slurry is first concentrated in the low-
sodium
concentration and brine removal system 4 to cause its solid mass content to
reach 40%-45%,
obtaining the second overflow liquid. The second overflow liquid is a solution
mainly
including magnesium chloride; then, the low-sodium carnallite slurry is
centrifuged to remove
brine to finally obtain the first filtrate and the low-sodium carnallite ore
with a <10% content
of moisture.
[0057] Particularly, the second overflow liquid may be used by the flotation
system 3 to
adjust the concentration of the pulp conditioned slurry, and the first
filtrate is recycled by the
overflow liquid and filtrate treatment system 8; then, the low-sodium
carnallite ore with a
<10% content of moisture enters the next procedure.
[0058] The low-sodium carnallite ore with a <10% content of moisture is
transferred to the
cold crystallization and crude potassium screening system 5 where it is
decomposed by a
decomposing mother liquor and then crystallized to control supersaturation of
the potassium
chloride in the solution to thereby reduce the amount of potassium chloride
crystals. which
achieves the objective of causing the potassium chloride crystals to grow
under a room
temperature; further, as the sodium chloride cannot be separated out in an
unsaturated state,
the quality and granularity of the potassium chloride product is guaranteed.
Then, a screening
operation is performed, where the screen overflow coarse-grained carnallite
which has not
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been decomposed yet returns to the crystallizer 51 to be re-decomposed, and
then the crude
potassium screen undertow enters the next procedure.
[0059] The third overflow liquid and the third undertow slurry are produced in
the
decomposition and crystallization process, wherein the third overflow liquid
is recycled by
the overflow liquid and filtrate treatment system 8 for synthesizing the
decomposing mother
liquor. The solid mass content of the third undertow slurry is 17-27%, mainly
including
coarse-grained carnallite which has not been decomposed and fine-grained
potassium chloride.
The third undertow slurry is screened to obtain the crude potassium screen
overflow and the
crude potassium screen undertlow, wherein the crude potassium screen overflow
returns to the
crystallizer 51 to be re-decomposed, and the crude potassium screen underflow
enters the
crude potassium concentration and brine removal system 6.
[0060] The crude potassium concentration and brine removal system 6
concentrates the
crude potassium screen undertow to obtain the fourth undertow slurry and the
fourth
overflow liquid, wherein a solid mass content of the fourth underflow slurry
is 40%-45%;
then, the fourth underflow slurry is subjected to brine removal to obtain the
second filtrate and
the crude potassium ore with a <10% content of moisture; the second filtrate
returns to the
concentration procedure to be recovered; the fourth overflow liquid is
transferred to the
run-of-mine screening system where brine is mixed to recover the carnallite in
the liquid
phase; and the crude potassium ore with a <10% content of moisture enters the
next
procedure.
[0061] The refined potassium washing and brine removal system 7 washes the
crude
potassium ore with a <10% content of moisture to further dissolve the
magnesium chloride
and the potassium chloride; fresh water is added based on a conductivity to
adjust the slurry
concentration to a 40%-45% solid mass content; the washed slurry is then
concentrated to
obtain the fifth overflow liquid and the fifth underflow slurry, wherein the
fifth overflow
liquid is used by the overflow liquid and filtrate treatment system 8 for
blending the
decomposing mother liquor, and the fifth undertow slurry partially returns to
the washing
procedure for adjusting the concentration of the washed slurry, but a large
part enters the brine
removal procedure to remove brine from the fifth undertow slurry to thereby
obtain a refined
potassium ore, which has a <10% content of moisture: during the brine removal
process, the
third filtrate is further obtained, wherein the third filtrate is available
for being recycled during
the internal concentration process of the refined potassium washing and brine
removal system
13
CA 3053055 2019-08-26
7.
[0062] Fig. 2 is a schematic diagram of an overflow liquid and filtrate
treatment system
according to an embodiment of the present disclosure.
[0063] As shown in Fig. 2, the overflow liquid and filtrate treatment system 8
comprises a
first treatment system 81, a second treatment system 82, and a third treatment
system 83,
wherein the first treatment system 81, which is respectively connected to the
run-of-mine
treatment system I and the flotation system 3, is configured to receive the
first overflow
liquid from the run-of-mine treatment system 1 and receive the floatation
tailings from the
flotation system 3, wherein the first overflow liquid and the flotation
tailings are subjected to
pulp conditioning and then discharged; the second treatment system 82, which
is respectively
connected to the cold crystallization and crude potassium screening system 5
and the refined
potassium washing and brine removal system 7, is configured to receive the
third overflow
liquid from the cold crystallization and crude potassium screening system 5
and receive the
fifth overflow liquid from the refined potassium washing and brine removal
system 7,
wherein the third overflow liquid and the fifth overflow liquid, after being
conditioned by
fresh water, are transferred to the cold crystallization and crude potassium
screening system 5
as the decomposing mother liquor; and the third treatment system 83, which is
connected to
the low-sodium concentration and brine removal system 4, is configured to
receive,
concentrate, and filter the first filtrate to recover the carnallite.
[0064] The flotation tailings are froth with solid sodium chloride, which are
not easy to be
discharged; but by mixing it with the first overflow liquid, it becomes easier
to transfer.
Additionally, the flotation tailings include a large amount of sodium
chloride, which, after
being dissolved using the first overflow liquid, may be further used as a raw
material to
recover the sodium chloride.
100651 The decomposing mother liquor is used in the cold crystallization and
crude
potassium screening system 5 for decomposing the slurry in the crystallization
procedure.
[00661 The first filtrate includes fine-grained carnallite. In the present
disclosure, the
concentrated first filtrate is filtered by a horizontal belt filter to recover
the fine-grained
carnallite.
[0067] The first treatment system 81 may comprise a tailing settling pond, a
tailing cell, and
etc., wherein the tailing cell is used to receive the tailings and the first
overflow liquid, such
that the tailings may be transferred smoothly. The remainder of the first
overflow liquid may
14
CA 3053055 2019-08-26
be discharged to the tailing settling pond, which, after being settled, is
discharged to the
carnallite salt pan to be recovered.
[0068] The second treatment system 82 may be a dissolving tank to receive the
third
overflow liquid and the fifth overflow liquid, wherein fresh water may be
added to blend the
decomposing mother liquor.
[0069] The third treatment system 83 comprises a concentrator and a
centrifugal machine or
comprises a concentrator and a belt filter.
[0070] According to an embodiment of the present disclosure, the low-sodium
concentration
and brine removal system 4, which is connected to the flotation system 3, is
configured to
transfer the second overflow liquid to the flotation system 3 to adjust a
concentration of the
pulp conditioned slurry.
[0071] The second overflow liquid is preferably transferred to the flotation
system 3 to
adjust the concentration of the pulp conditioned slurry, while the extra
second overflow liquid
may return to the carnallite salt pan to be recovered.
[0072] According to an embodiment of the present disclosure, the crude
potassium
concentration and brine removal system 6, which is connected to the run-of-
mine treatment
system 1, is configured to transfer the fourth overflow liquid to the run-of-
mine treatment
system 1 to blend the carnallite slurry.
[0073] Fig. 3 is a schematic diagram of the first treatment system according
to an
embodiment of the present disclosure.
[0074] As shown in Fig. 3, the first processing system 81 further comprises a
primary
scavenging cell 811, a secondary scavenging cell 812, and a storage tank 813,
wherein the
primary scavenging cell 811, when being connected to the flotation system, is
configured to
receive the floatation tailings and perform primary scavenging to obtain a
primarily
scavenged froth and a primarily scavenged underflow; the secondary scavenging
cell 812,
when being connected to the primary scavenging cell 811, is configured to
receive the
primarily scavenged underflow, and perform secondary scavenging to obtain a
secondarily
scavenged froth and a secondarily scavenged underflow; the primary scavenged
cell 811,
when being connected to the tailing pond, is configured to transfer the
primarily scavenged
froth to the tailing pond; the secondary scavenging cell 812, when being
connected to the
storage tank 813, is configured to transfer the secondarily scavenged
undertlow to the storage
CA 3053055 2019-08-26
tank 813; and the secondary scavenging cell 812, when being connected to the
low-sodium
concentration and brine removal system 4, is configured to transfer the
secondarily scavenged
undertlow to the low-sodium concentration and brine removal system 4.
[0075] The primary scavenging cell 811 performs primary scavenging to the
flotation tailing
froth to obtain the primarily scavenged froth and the primarily scavenged
underflow. wherein
a dominant portion of the flotation reagent in the primarily scavenged froth
is bonded with the
sodium chloride such that it is hard to be recycled. Meanwhile, the primarily
scavenged froth
has a relatively low content of potassium chloride, which can hardly be
recovered in the prior
known system to provide an economic benefit. The present disclosure adopts an
approach of
discharging the primarily scavenged froth and the first overflow liquid into
the tailing pond
for treatment. The secondary scavenging cell 812 is designed to be lower than
the primary
scavenging cell 811 such that the primarily scavenged underflow automatically
flows into the
secondary scavenging cell 812 to be subjected to the secondary scavenging to
obtain the
secondarily scavenged froth and the secondarily scavenged underflow. The
secondarily
scavenged underflow may also be transferred as the low-sodium slurry to the
low-sodium
concentrator to go through subsequent procedures. The secondarily scavenged
froth includes a
large amount of flotation reagent which is not bonded with the sodium chloride
yet, as well as
a portion of flotation reagent which has been bonded with the potassium
chloride in the
primary scavenging process and has released the potassium chloride during the
second
scavenging enters the froth. Such portions of flotation reagent are the target
to be recycled in
the present disclosure.
[0076] The secondarily scavenged froth is collected into the storage tank 813
and transferred,
by a transfer pump, into the flotation distribution tray. On the one hand, the
flotation reagent
is recovered, and on the other hand, since the secondarily scavenged froth has
a relatively
high content of potassium chloride, it is also worthy of recovering. This
setting significantly
improves the flotation effect, saves the flotation reagent, and boosts the
yield of potassium
chloride.
[0077] Fig. 4 is a schematic diagram of the run-of-mine treatment system
according to one
embodiment of the present disclosure.
[0078] As shown in Fig. 4, the run-of-mine treatment system 1 comprises a
carnallite
screening machine 11 and a run-of-mine concentrator 12, wherein the carnallite
screening
machine 11 is configured to screen off impurities and large-particle salt in
the carnallite pulp
16
CA 3053055 2019-08-26
to obtain a screen underflow product; and the run-of-mine concentrator 12,
which is
connected to the carnallite screening machine 11, is configured to concentrate
the screen
undertlow product to obtain the first overflow liquid and the first underflow
slurry, wherein a
solid mass content of the first underflow slurry is 30-45%, and the run-of-
mine concentrator
12 is provided in one or in plurality.
[0079] Impurities and large-particle salt and the like are screened off from
the carnallite pulp
by the carnallite screen machine 1 1 The screen underflow product enters the
run-of-mine
concentrator 12 to be concentrated. The first underflow slurry (with a 30%-35%
solid mass
content) is transferred to the pulp conditioning system 2 by an underflow
pump; part of the
first overflow liquid is mixed with the tailings and then discharged, and the
remainder of the
first overflow liquid is discharged to the carnallite salt pan to be recycled.
[0080] The run-of-mine concentrator 12 may be provided in plurality, wherein
the plurality
of run-of-mine concentrators 12 are arranged in parallel, such that even a
concentrator fails,
the operation of the entire production line would not be affected. In the
alternative, a plurality
of active concentrators and standby concentrators may be arranged to maintain
stability of the
total processing capacity of the run-of-mine concentrators 12.
[0081] Fig. 5 is a schematic diagram of a pulp conditioning system according
to one
embodiment of the present disclosure.
[0082] As shown in Fig. 5, the pulp conditioning system 2 comprises a slurry
distribution
tray 21 and a pulp conditioning tank 22, wherein the slurry distribution tray
21 comprises a
plurality of interfaces for connecting with the plurality of run-of-mine
concentrators 12, the
slurry distribution tray 21 being configured to receive the first underflow
slurry, mix the first
underilow slurry with the flotation reagent, and distribute the first
undertlow slurry and the
flotation reagent to the pulp conditioning tank 22; and the pulp conditioning
tank 22, which is
connected to the slurry distribution tray 21, is configured to uniformly
mixing the first
underflow slurry and the flotation reagent to obtain the pulp conditioned
slurry.
100831 The slurry distribution tray 21 receives the first underflow slurry
from the
run-of-mine concentrator 12; the flotation reagent is added into the slurry
distribution tray 21
based on the solid mass content of the first undertlow slurry, and then the
slurry enters the
pulp conditioning tank 22; meanwhile air of 0.5-0.7 Mpa is introduced via an
air compressor
into a ring pipeline at the bottom of the pulp conditioning tank 22, wherein a
large amount of
air bubbles with appropriate sizes pop out when the air passes through evenly
arranged air
17
CA 3053055 2019-08-26
holes on the ring-shaped pipeline; with mechanical agitation in the pulp
conditioning tank 22,
the sodium chloride is selectively attached to the air bubbles; finally, the
slurry enters the
flotation distribution tray 31, and after the concentration of the slurry is
adjusted (to a solid
mass content: 20%-25%) by adding a pulp conditioning mother liquor, enters the
flotation
system 3.
[0084] The slurry distribution tray 21, which is connected to a plurality of
run-of-mine
concentrators 12, mixes the underflow slurries from the plurality of
concentrators as well as
the flotation reagent, such that the compositions of the pulp conditioned
slurries are uniform
before the flotation procedure, and the flotation reagent is also uniformly
distributed in the
pulp conditioned slurries, thereby improving flotation efficiency.
[0085] Fig. 6 is a schematic diagram of a flotation system according an
embodiment of the
present disclosure.
[00861 As shown in Fig. 6, the flotation system 3 comprises a flotation
distribution tray 31
and a flotation machine 32, wherein the flotation distribution tray 31, which
is connected to
the pulp conditioning system 2, is configured to receive the pulp conditioned
slurry, and
perform concentration adjustment to the pulp conditioned slurry by adding an
adjustment
mother liquor to obtain an adjusted slurry, wherein a solid mass content of
the adjusted slurry
is 20%-25%, and the adjustment mother liquor refers to a liquid phase having
same
compositions as a slurry mother liquor; and the flotation machine 32, which is
connected to
the flotation distribution tray 31, is configured to perform roughing,
concentrating, and
scavenging operations on the adjusted slurry to obtain the tailings and the
low-sodium
carnallite slurry, wherein the flotation machine 32 is provided in one or in
plurality.
[0087] The flotation distribution tray 31 receives the pulp conditioned
slurry, the
concentration of which is adjusted using the adjustment mother liquor; then,
the adjusted
slurry is transferred to a plurality of flotation machines 32, which
guarantees consistency of
the material compositions in respective flotation machines 32 and facilitates
uniform control
of operation parameters of the flotation machines 32. The flotation includes
the following
steps: roughing, concentrating, and scavenging, thereby obtaining tailings and
the low-sodium
carnallite slurry.
[0088] Similar to the run-of-mine concentrator 12, the flotation machine 32
may also be
provided in one or in plurality; when the flotation machines are provided in
plurality, the
flotation machines 32 are arranged in parallel, thereby boosting the treatment
capacity of the
18
CA 3053055 2019-08-26
present disclosure.
[0089] The flotation distribution tray 31 enables consistency of various
properties of the
materials in respective flotation machines 32, which facilitates uniformly
setting flotation
conditions.
[0090] Fig. 7 is a schematic diagram of a low-sodium concentration and brine
removal
system according to one embodiment of the present disclosure.
[0091] As shown in Fig. 7, the low-sodium concentration and brine removal
system 4
comprises a low-sodium concentrator 41, a low-sodium centrifugal machine
distribution tank
42, and a low-sodium centrifugal machine 43, wherein the low-sodium
concentrator 41 is
configured to receive the low-sodium carnallite slurry and concentrate the low-
sodium
carnallite slurry to obtain the second underflow slurry and the second
overflow liquid,
wherein a solid mass content of the second underflow slurry is 40%-45%; the
low-sodium
concentrator 41 is provided in one or in plurality; the low-sodium centrifugal
machine
distribution tank 42, which is connected to the low-sodium concentrator 41, is
configured to
receive the second underflow slurry and distribute the second underflow slurry
to the
low-sodium centrifugal machine 43; the low-sodium centrifugal machine 43,
which is
provided in one or in plurality and is connected to the low-sodium centrifugal
machine
distribution tank 42, is configured to remove brine from the second underflow
slurry to obtain
the first filtrate and the low-sodium carnallite ore with a <10% content of
moisture.
[0092] The low-sodium concentrator 41 receives the low-sodium carnallite ore,
which is
concentrated to obtain the second underflow slurry and the second overflow
liquid, wherein
the low-sodium concentrator 41 is connected to the flotation distribution tray
31 to transfer
the second overflow liquid to the flotation distribution tray 31 as the
adjustment mother liquor.
By controlling the underflow flow rate and concentration, the low-sodium
concentrator 41
causes the solid mass content of the second underflow slurry to be 40%-45%,
thus improving
the yield of centrifuged brine removal. Meanwhile, the low-sodium concentrator
41 may be
provided in plurality, and the plurality of low-sodium concentrators 41 are
connected in
parallel with the flotation machine 32; as such, the treatment capacity of the
low-sodium
concentrator 41 may be enhanced.
[0093] The low-sodium centrifugal machine distribution tank 42 is connected to
the
low-sodium concentrator 41; when the current system has a plurality of low-
sodium
concentrators 41 connected in parallel, the second underflow slurrys
discharged from
19
CA 3053055 2019-08-26
respective low-sodium concentrators 41 are uniformly mixed in the low-sodium
centrifugal
machine distribution tank 42 and then distributed to the low-sodium
centrifugal machine 43
for brine removal.
[0094] The low-sodium centrifugal machine 43 may be provided in one or in
plurality.
When a plurality of low-sodium centrifuges 43 are provided, the overall
treatment capacity
may increase; besides, failure of a certain low-sodium centrifugal machine 43
does not affect
the entire production line.
[0095] Fig. 8 is a schematic diagram of a cold crystallization and crude
potassium screening
system according to one embodiment of the present disclosure.
[0096] As shown in Fig. 8, the cold crystallization and crude potassium
screening system 5
comprises a crystallizer 51 and a crude potassium screening machine 52,
wherein the
crystallizer 51, which is provided in one or in plurality, is configured to
receive, decompose,
and crystallize the low-sodium camallite ore with a <10% content of moisture
to obtain the
third underflow slurry and the third overflow liquid, wherein a solid mass
content of the third
undertlow slurry is 15% ¨ 30%; and the crude potassium screening machine 52,
which is
connected to the crystallizer 51, is configured to screen the third underflow
slurry to obtain
the crude potassium screen overflow and the crude potassium screen underflow.
[0097] The crystallizer 51 is connected to the low-sodium centrifugal machine
43. The
centrifuged low-sodium carnallite ore with a <10% content of moisture enters
the crystallizer
51; meanwhile, the decomposing mother liquor is added to decompose and
crystallize the
low-sodium carnallite ore at a controlled rate, wherein by controlling a
decomposition
condition of the low-sodium carnallite ore, the supersaturation of the
potassium chloride in
the solution is controlled, which reduces the amount of potassium chloride
crystals, thereby
reaching the purpose of growing the potassium chloride crystals at a room
temperature.
Further, the sodium chloride cannot be separated out when its liquid phase is
in an unsaturated
state, which guarantees the quality and granularity of the potassium chloride
product. In this
way, the third underflow slurry and the third overflow liquid are obtained.
The solid mass
content of the third underflow slurry is 17%-27%. The third underflovv slurry
is transferred to
the crude potassium screen machine for being screened, wherein the screen
overflow
coarse-grained carnallite which has not been decomposed yet returns to the
crystallizer 51 to
be re-decomposed, and the crude potassium screen underflow enters the crude
potassium
concentrator 61. The third overflow liquid is treated by the overflow liquid
and filtrate
CA 3053055 2019-08-26
treatment system 8 for blending the decomposing mother liquor.
[0098] Fig. 9 is a schematic diagram of a crude potassium concentration and
brine removal
system according to one embodiment of the present disclosure.
[0099] As shown in Fig. 9, the crude potassium concentration and brine removal
system 6
comprises a crude potassium concentrator 61, a crude potassium centrifugal
machine
distribution tank 62, and a crude potassium centrifugal machine 63, wherein
the crude
potassium concentrator 61, which is provided in one or in plurality, is
configured to receive
and concentrate the crude potassium screen underflow to obtain the fourth
overflow liquid
and the fourth undertlow slurry, wherein a solid mass content of the fourth
undertlow slurry is
40%-45%; the crude potassium centrifugal machine distribution tank 62, which
is connected
to the crude potassium concentrator 61, is configured to receive the fourth
underflow slurry
and distribute the fourth underflow slurry to respective crude potassium
centrifugal machines
63; the crude potassium centrifugal machine 63, which is provided in one or in
plurality and
connected to the crude potassium centrifugal machine distribution tank 62, is
configured to
remove brine from the fourth underflow slurry to obtain the second filtrate
and the crude
potassium ore with a <10% content of moisture.
[00100] The crude potassium concentrator 61 receives the crude potassium
screen underflow,
which is concentrated to obtain the fourth undertlow slurry and the fourth
overflow liquid.
The solid mass content of the fourth undertlow slurry is 410%-45%, which is
transferred to the
crude potassium centrifugal machine distribution tank 62 to be uniformly
distributed to the
crude potassium centrifugal machine 63 for brine removal, thereby obtaining
the second
filtrate.
[001011 Particularly, the crude potassium concentrator 61 is connected to the
run-of-mine
concentrator 12 of the run-of-mine treatment system 1, configured to transfer
the fourth
overflow liquid to the run-of-mine concentrator 12 to recover the carnallite
therein.
[00102] The crude potassium centrifugal machine 63 is connected to the crude
potassium
concentrator 61, and the second filtrate is transferred from the crude
potassium centrifugal
machine 63 to the crude potassium concentrator 61 to be recycled.
[00103] According to an embodiment of the present disclosure, the crude
potassium
centrifugal machine 63, which is connected to the crude potassium concentrator
61, is
configured to transfer the second filtrate to the crude potassium concentrator
61 to be
recycled.
21
CA 3053055 2019-08-26
[00104] Fig. 10 is a schematic diagram of a refined potassium washing and
brine removal
system according to one embodiment of the present disclosure.
[00105] As shown in Fig. 10, the refined potassium washing and brine removal
system 7
comprises a repulp washing tank 71, a refined potassium concentrator 72, and a
refined
potassium centrifugal machine 73, wherein the repulp washing tank 71, which is
provided in
one or in plurality, is configured to receive and wash the crude potassium ore
with a _<10%
content of moisture to obtain a repulpped slurry; the refined potassium
concentrator 72, which
is provided in one or in plurality and corresponds to the repulp washing tank
71, is configured
to concentrate the repulpped slurry to obtain the fifth underflow slurry; the
refined potassium
centrifugal machine 73, which is provided in one or in plurality and matched
to the refined
potassium concentrator 72, is configured to remove brine from the fifth
underflow slurry to
obtain the refined potassium ore and the third filtrate, wherein the refined
potassium ore has a
l0% content of moisture.
[00106] According to an embodiment of the present disclosure, the refined
potassium
concentrator 72, which is connected to the repulp washing tank, is configured
to adjust a
concentration of the crude potassium ore with a <10% content of moisture using
the fifth
underflow slurry. The refined potassium concentrator 72, which is connected to
the refined
potassium centrifugal machine 73, is configured to recover the third filtrate
to the refined
potassium concentrator 72 to be concentrated.
[00107] The crude potassium ore with a <10% content moisture, after having
been
centrifuged by the crude potassium centrifugal machine 63, enters the repulp
washing tank 71,
where fresh water is added based on electrical conductivity and the slurry
concentration in the
repulp washing tank 71 is adjusted using the fifth underflow slurry from the
refined potassium
concentrator 72 to reach a 40%-45% solid mass content; the washed slurry
enters the refined
potassium concentrator 72 to be concentrated to obtain the fifth overflow
liquid and the fifth
underflow slurry. A large portion of the fifth underflow slurry enters the
refined potassium
centrifugal machine 73 for brine removal to obtain a potassium chloride wet
feed (the refined
potassium ore with a content of moisture <10%), while the remainder is used
for adjusting the
pulp concentration in the repulp washing tank 71.
[00108] The third filtrate returns to the refined potassium concentrator 72 to
be recovered.
[00109] The fifth overflow liquid is recovered by the overflow liquid and
filtrate treatment
system 8 for blending the decomposing mother liquor to be used by the
crystallizer 51.
22
CA 3053055 2019-08-26
[00110] Fig. 11 is a schematic diagram showing steps of a method for producing
potassium
chloride by recycling byproducts.
[00111] As shown in Fig. 11, a method for producing potassium chloride by
recycling
byproducts is provided, comprising: step SI: screening and concentration a
carnallite pulp to
obtain a first undertlow slurry and a first overflow liquid; step S2: mixing a
flotation reagent
with the first underflow slurry to obtain a pulp conditioned slurry; step S3:
performing a
flotation operation on the pulp conditioned slurry to obtain tailings and a
low-sodium
carnallite slurry; step S4: concentrating and removing brine from the low-
sodium carnallite
slurry to obtain a second overflow liquid, a first filtrate, and a low-sodium
carnallite ore with
a i<_10% content of moisture; step S5: decomposing, crystallizing, and
screening the
low-sodium carnallite ore with a <10% content of moisture to obtain a third
overflow liquid, a
crude potassium screen overflow, and a crude potassium screen underflow; step
S6:
concentrating and removing brine from the crude potassium screen undertiow to
obtain a
fourth overflow liquid, a second filtrate, and a crude potassium ore with a
<10% content of
moisture; step S7: washing and removing brine from the crude potassium ore
with a <10%
content of moisture to obtain a third filtrate and a refined potassium ore;
and step S8:
recovering and treating the first overflow liquid, the third overflow liquid,
the fifth overflow
liquid, and the first filtrate.
[00112] According to an embodiment of the present disclosure, the step S8
comprises:
performing pulp conditioning to the first overflow liquid and the flotation
tailings and then
discharging the pulp conditioned first overflow liquid and flotation tailings;
receiving the
third overflow liquid and the fifth overflow liquid, which, after being
conditioned by fresh
water, are used as a decomposing mother liquor for a crystallization process;
receiving,
concentration, and filtering the first filtrate to recover carnallite.
[00113] According to an embodiment of the present disclosure, the method
further comprises
performing primary scavenging to the flotation tailings to obtain a primarily
scavenged froth
and a primarily scavenged undertlow; performing secondary scavenging to the
primarily
scavenged underflow to obtain a secondarily scavenged froth arid a secondarily
scavenged
underflow; performing pulp conditioning to the primarily scavenged froth and
the first
overflow liquid and then transferring the pulp conditioned primarily scavenged
froth and first
overflow liquid to a tailing pond; and transferring the secondarily scavenged
underflow to a
low-sodium concentration and brine removal system.
23
CA 3053055 2019-08-26
[00114] According to an embodiment of the present disclosure, the second
overflow liquid is
used for adjusting a concentration of the pulp conditioned slurry.
[00115] According to an embodiment of the present disclosure, the fourth
overflow liquid is
used for blending the carnallite pulp.
[00116] According to an embodiment of the present disclosure, the step SI
comprises:
screening off impurities and large-particle salt in the carnallite pulp to
obtain a screen
underflow product; and concentrating the screen underflow product to obtain
the first
overflow liquid and the first underflow slurry, wherein a solid mass content
of the first
underflow slurry is 30-45%, and a solid mass content of the carnallite pulp is
>25%.
[00117] According to an embodiment of the present disclosure, the step S2
comprises: mixing
the first underflow slurry with the flotation reagent, and distributing the
first underflow slurry
and the flotation reagent; and uniformly mixing the first underflow slurry and
the flotation
reagent to obtain a pulp conditioned slurry.
[00118] According to an embodiment of the present disclosure, the step S3
comprises:
performing concentration adjustment to the pulp conditioned slurry by adding
an adjustment
mother liquor to obtain an adjusted slurry, wherein a solid mass content of
the adjusted slurry
is 20%-25%, and the adjustment mother liquor refers to a liquid phase having
same
compositions as a slurry mother liquor; and performing roughing,
concentrating, and
scavenging operations on the adjusted slurry to obtain the tailings and the
low-sodium
carnallite slurry.
[00119] According to an embodiment of the present disclosure, the step S4
comprises:
concentrating the low-sodium carnallite slurry to obtain the second underflow
slurry and the
second overflow liquid, wherein a solid mass content of the second undertlow
slurry is
40%-45%; distributing the second underflow slurry; removing brine from the
second
underflow slurry to obtain the first filtrate and the low-sodium carnallite
ore with a <10%
content of moisture.
[00120] According to an embodiment of the present disclosure, the step S5
comprises: mixing
the low-sodium carnallite ore with a <10% content of moisture with a
decomposing mother
liquor to perform decomposition and crystallization under a controlled speed
to thereby obtain
the third underflow slurry and the third overflow liquid, wherein a solid mass
content of the
third underflow slurry is 15% ¨ 30%; and performing a screening operation on
the third
underflow slurry to obtain the crude potassium screen overflow and the crude
potassium
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screen underflow.
[00121] According to an embodiment of the present disclosure, the step S6
comprises:
concentrating the crude potassium screen undertlow to obtain the fourth
overflow liquid and
the fourth underflow slurry;, wherein a solid mass content of the fourth
underflow slurry is
40%--45%; distributing the fourth underflow slurry; removing brine from the
fourth
underflow slurry to obtain the second filtrate and the crude potassium ore
with a <10%
content of moisture.
[00122] According to an embodiment of the present disclosure, the second
filtrate is
transferred to a procedure of concentrating the crude potassium screen
undertlow for being
recycled.
[00123] According to an embodiment of the present disclosure, the step S7
comprises:
washing the crude potassium ore with a <10% content of moisture to obtain a
repulpped slurry;
concentrating the repulpped slurry to obtain the fifth underflow slurry;
removing brine from
the fifth underflow slurry to obtain the refined potassium ore and the third
filtrate, wherein the
refined potassium ore has a <10% content of moisture.
[00124] According to an embodiment of the present disclosure, in a repulp
procedure, a
concentration of the crude potassium ore with a <10% content of moisture is
adjusted using
the fifth underflow slurry; and the third filtrate is recovered to a repulpped
slurry
concentration procedure so as to be thickened.
[00125] In the present disclosure, by recycling the first overflow liquid, the
third overflow
liquid, the fifth overflow liquid, and the first filtrate to the system
respectively, intra-system
recovery of potassium chloride is implemented to replace adding external
materials, which, on
one hand. increases the yield of potassium chloride, and on the other hand,
saves costs. In the
present disclosure, by parallel connecting the devices such as the run-of-mine
concentrator 12,
the flotation machine 32, and the low-sodium concentrator 41 and by uniform
pulp
conditioning with the pulp conditioning tank 22 and scattered distribution,
the treated
concentration of the material is made uniform; besides, due to the mutual
standby relationship
among the parallel-connected devices, failure or overhaul of one device does
not affect
operation of the overall process.
[00126] It should be noted that, the examples above are intended to illustrate
the present
disclosure, not to limit the present disclosure. Without departing from the
scope of the claims,
those skilled in the art may devise alternative examples. In the claims, no
reference numerals
CA 3053055 2019-08-26
placed in the parentheses should be construed as any limitation to the claims.
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