Note: Descriptions are shown in the official language in which they were submitted.
1~5~0~1
A METHOD ~R TREATING SULFIDE RAW M~rERIAl.S
The fleld of ~echnology
The present ~nYentien relates to the field of non-ferrous
metallurgy and more speci~ically to method for treating sul~i-
de raw materials.
The treat~ent o~ sulfide raw material~ is aimed at reco-
very of metals and sulIur therefrom. Sul~ide raw materials
include ores, for in~tance, copper~ copper-zinc, copper-nickel
ores, concentrates and intermedlate products of ore beneficia-
tion.
Background of the in~ention
Treatment of sul~ide raw materials implie~ direct reco-
very o~ ~etal therefrom or recovery o~ metal into a matte that
is then converted for product~on of metal or inriched ~ulfide
phase (e.g. copper-and-nickel converter matte produced by smelt-
ing copper-nickel ra~ ma~erials) from which metals are reco~er-
ed by subsequent proce~sing. ~irect recovery o~ metal, in parti-
cular ¢opper~ ~rom sulfide raw Material~ i8 accomplished in a
~in~le uni~ or in a number of unit3 ~or continuou~ smelt~n~
prQce~ ln 3erie~, ~he kno~n method~ for con~inuou~ smelting
have, however~ not till now come ta an exten~ive commercial u~e.
In the practice o~ non~errou~ extractive metall~rgy, methods
~re primaril~ in use implying the recoYery o~ me~al8 in the
form Q~ matte, ~rom which metal~ are produced by a ~ubsequen~
proce~sin~.
- 2 -
115~0~1
The ~nown ~ethods for treatin~ sulfide raw materials to
produce matt~ include smel-ting of raw material~ in bla~t 7 re-
verb~ratory, electric and flash smslti~g furnace~.
The blast furnace smelting requires a char~ con~aining
raw materi~l and flux, the use o* a ca:rbonaceou3 ~uel7 mainly
coke, and oxygen-containin~ ga~ blowingO All the kno~n ~ethods
for smelt~ng sul~ide ra~ material~ in blast furnaces involve
the use of c~rbonaceous fuel.
Dep~nding on the compo~itions of the initial raw mat~rial
and of the produced ~roduct~, the methocls for sulfide raw mate-
rial treatment in bla~t furnace~ are divided into pure p~rite
~meltingt partial pyrite smelting and copper-and-sulfur smelt-
ing (Orkla process).
To treat massive p~ritic copper ores (i.e. or~s with a
low ga~gue content) containing at least 32% sulfur, pure py-
rite smelti-ng was used. This method involved ~melting o~ char-
ge, co~sisting of ore with flux (quartz a~d limestone) additions
and up to 3~ wt~ of coke, in a blast furnace with a~ open th~oat
and with air blowing at a rate of about 1,000 to 1,200 m3/tonne
of ore. The oxygen consumption amounts to about 210 to 250 m3~
/tonne of ore. During smelting, copper is recovered into matte,
~ulfur pan~es into off-ga~ Smirnov V.I. Met~llu.r~y o~ copper
and nic~el, Sv~rdlovsk-Moscow, M~tallur~izda~, lg501 p, 176~255?
and in particular pO lB8, 195, 200, 252; Peter~ E.D. ~he Practi-
~e o~ Copper 5mel~ing, New York, ~acGraw-Hill Book Company~ 1911
p. ~04-242, and in part~cular p. 236).
~ rhi~ m~thod provided a high rate o~ desul~uriza~ion ~up to
95~0) and a hi~h ratio o~ conc~ntration (up to 20-~5:1).
_ 3 _
0 5 1
The concentration ratlo i~ the ralationship between the copper
conte~t in matte and the copper content in initial raw mate-
rial. Howeverl the pure pyrite smelting process ~as difficult
to control because o~ a unstable hea~ balance and because of
a long time required for the charge to pass through -the fur-
nace. Furthermore, fuel required for the process operation was
expensive coke in an amount of up to 2~5-3% of the total charge
weight. Some attempts wer~ made to implement the pure pyrite
smelting without coke additions, i.e. autoeenou~lyt but no po-
sitive results were attained if the process had to be conduct-
ed for a longer (several day~) period (Sticht X.S. ~ber da~
~esen des Pyrit-Sch~melzverfahrens, Halle, ~ilhelm Knapp, Metal-
lurgie, May 1906, N 9, S. 269). It should be noted that during
the pure pyrite smelting process sulfur was normall~ lost with
off-gase~ and had to be emitted into the atmosphere, whereby
the environment was contaminated. ~his process was in common use
at the beginning of the 20th century, but later a change over
to partial pyrite smelting was done due to a gradual exhaustion
of mas~ive copper pyrite ore deposits.
~ he partial pyrite smelting i~ conducted on copper pyrite
ore and/or lump-size concentrates, containing less than 32%
sulfur. This method implie~ smelting of a charge that consist~
of ore and~or conc~ntrates wi~h ~lux addition~ and o~ up to
1~.5% wt, carbonaeeous fuel, usuall~ coke, ~ a bla~t fur~ace
with an open or sealed throat and an ~lr or oxygen-~nriched
blowing~
?he u~e of other carbonaceous ruel~, e.g~ pulverized coal,
fuel oil, or na~ural ga~ introduced through the tuyere~ or the
~ 1 5 ~
use of them in -the form of combustion products fed abo~e the
tuyeres, allows one to reduce the consumptio~ of expensive co-
ke to a certain extent, but doe~ not completely elimina~e its
use.
The air blo~ rate amount~ up to 1,500 m3/tonne of sulfide
raw material or even rnore~ while the oxygen-enriched blow rate
is about 775 to 1,215 m3/tonne o~ sulfide material. The actual
oxygen requirementi for smeltlng one tonne of sulfide raw mate-
rlal, taking into account oxygen needed Ior coke combustion~
does not exceed 150 m3. During smeltir~, copper i~ recovered
into matte, sulfur tran~3fers into off-gas (Smirno~ V.I. Metal-
lurgy of Copper and Nickel7 Sverdlovsk-~oskow, Metallurgizdat~
1950, p. 199-2119 and in par-ticular p. 200 a. 252; IJebedev ~.I.
et al., Copper blast ~melting with ox~gen-enriched blowing,
"~svetnyey metally", 1961, N 3, p. 32-39).
The partial pyrite smelting process provide~ a lower, a3
compared to the pure pyrite smelting ? extent of desulfuriza-
tion (up to 79~0), a lower ratio of concentration (up to 4 5:1)
and a low S02 content (2 to 5%) o~ the off-gas, which makeQ i~
difficult to recovsr sulfur therefrom. Furthermore, thi~ met-
hod involves a higher consumption of expensive and ~.hort-o~-
-supply coke a~ a heat source. The use of oxyge~enriched blow-
in~ allow~ to cut down the coke .r~uirements, but by no ~ore
than 30%~
l'h~ pa~t-lfll p~r~te ~melting process :L~ o applled for
treatlng copper-nlckel sulfide or~ and/or con~en~rate~ o~ p~r-
rhotit~ t~pe pro~iding a de~ulfurization rate o~ up to 50 to
65~. Whe~ ~mel~ing ~uch ~ raw mate~ial a~d u~ing ox~gen-enriched
-- 5 -
~ 156~51
blowing, the co~e consumption decrea~e~, but by no more than
40%~ ~Ind i8 maintained at about 5.8% of the charge weight (Bi3-
wa~ A., Davenport WD ExkractiYe li~etallurgy of Copper, Oxford,
Pergamon Press, 1976~ p. 100-109).
During 1930s the so-called copp~r-and sulfur process
(Orkla met~od) wa~ developed for smelting sulfide raw materials.
T~is method is used to treat copper pyrite ores with a sulfur
conten~ of 40 to 45~. This process involves smelting a charge~
con~3isting of ore and f.luxe~ with addition of solid carbona-
c~ou~ ma~erial, e.g~ cok~, in an amount of 10% o~ the total
charga weight, in a blast furnae with a sealed throat. '~h~
smelting process is accomplished ~ith air blowi~g at a rate of
up to 1,000 m3/tonne of ore, and the oxygen consumption here-
with amount~ to 210 m3/tonne of ore. The actual oxygén requi-
rement is e~en lower becallse some ox~gen of the blow air is
used for combustion of a part o~ coke that plays a role of fuel
in the smelting proces~ Another part o~ coke burns in the midd-
le zone of the furnace to pro~ide reduction of S02 formed as a
result of ~eS oxjdation in the bottom zone of the furnace. The
products of the ~melting proces~ are matte, slag, elemental sul-
~ur and sulfur-bearing gases, from which additional elemental
sulfur is recovered in the presence of a cataly~t (US Patent
1,860,5~5, Cl. 23-226, ~ay 31, 1932).
~ hi8 mothod p.rov:ide~ a ~3uffi.c:iantl~y high sul.~ur recove~y
in kho ~or~ o:~ elemen~al sulfur from sulfide m~berial~, which
i~ a ~ub~banti~l advant~ge in comparison to othex me~hod~. On
the other hand, thi~ method show~ a low desul:furization rate
~ t 5605 1
(up to 85%) and a low rate of cvncentration (up to 5.5:1). As
a result, -treatment of ores, containing9 for example, 2.5% cop-
per, yields low-grade matte~, containing 8 tc 107o a~d maximum
14 to 15~o copper. Prior to converting, such matte~ should be
subjected to additional treatment in a upgrading smelting fur~
nace (concentration smelting) and this increases the cost of
raw material processing. This proces~ also require~ the use
of coke, not only as a reductant for recove~y o~ sulfur from
S02, but also a~ fuel. ~urthermore, this process i~ hard to
control, because it takes a long time for the charge to pass
throu~h the furnace. Sulur-bearing gases~ after a catalytic
treatment, have to be discharged into the atmosphere because
sul*ur i5 difficult to recover therefrom.
Objective of the invention
The main objectiv~ o~` the said invention ~s to impro~e
the sulfide raw material~ treatment in bla~t ~urnaces, and to
reduce the costs o~ raw material processing, and to increase
the sulfur reco~ery therefrom~
Summary of the invention
~ he ob~ecti~e o~ the said inYention was attalned by using
a method :~or treating ~ulfide raw materials in a bla~t furnace~
the said met~od comprising the smelting of a ch~rge, con~l~t-
lng of metal-bearing raw material and ~luxe~ with oxygen-co~-
taining g~ blowing to produce matte, ~lag, elemental sul~ur
0 ~ 1
and sulfllr-bearing off-~a~. The part~cular feature oP the said
method i8 th~t the charge smelting is conducted autogenou~s~y in
a furnace with a quartz la~er 0.3 to 1.5 m high lmmediately abo-
ve the tuyeres, which allows to maintain a desired amount o~
charge to be ~melted a3 per 1 m2 of the furnace cro~s sectio~
vlithin the tuyere zone and per a unit of time and to ensure a
sufficiently complete oxydation of iron sulfide~ that form~ as
a result of higher sulfides contained i.~ the initial raw mate-
rial, by the oxygen supplied with oxygen-enriched air blowing
with an o~ygen consurnptiion rate o~ 300 to 400 m3/tonne of sul-
~ide raw material.
As the sulfide raw material treatment is accomplished
autogenously, i.e. without use of coke or any other carbonace-
ous fuel, the cost of the process is substantially lower.
This is a major merit o~ the said invention.
The said method allows one to produce high-grade matte~
in a ~ingle step and to increase the sulfur recovery from the
raw material. .
The advantages o~ the said invention include al~o its
applicabilit~ to a ~ido variety o~ sulfide raw materials, for
example, copper, copper-zinc, and copper-nickel orec3; lump-size
copper, pyrite, and pyrrhotite concentrates, and intermediate
produc~3. rrhe merlt3 af the said lnvention will be illu~trated
th~ ~oll~win~ d~tai.led description.
Detail~d descriptlon ~ the inv~tion
rrh~ ~aid method for tr~ating ~ulfide raw material~ com-
pri3e~ smelting o~~a charg~, con~i~ting o~ raw matorial and
- 8 -
1 1~6~Sl
fluxes in a bla~t furnace, where a quartz layer 0.3 ko 1.5 m
high ~ provided immediately above the tu~eres. q'hrough the
tuyeres, oxygen-enriched air is supplied into the furn~ce. The
oxygen requirement amount~ to 300 to 400 m3/tonne of sulfide
raw material.
When testing the smelting process with oxygen-enriched
air blowing, it wa~ found that the consumption of coke a~ fuel
can be reduced. Complete elimination o~ the use of coke as fuel,
however, can be ach~eved, a~ i~ was ~ound~ only when the mention-
cd feature~ of the said invention, i,e. the above hei~ht o~ the
rquartz layer and the specified oxygen requirement, are proviAed.
The said method for processing sulfide raw material~ i~ ac-
complished in a blast furnace of a common design with a her~eti-
cally sealed throat used for non-ferrous metal production. The
charge consisting of sulfide ore and/or lump-slze sul~ide mate-
rials (e,q. briquetted concentrate) and fluxes (quartz and li-
mestone) is fsd into the furnaca through a ch~rging device en
suring hermeticity~ Individual component~ o~ the char~e shall
be in the form of lump~, prefer,ably of not too large a size
not more than 100-120 mm. To provide the required gascous im-
permeability of the charge within the furnace the share of the
frac-tio~ ~ize minu~ 20 mm should not exceed 5 to 10%. It i~ pre-
~er~able to rni~ cQMponents of t;he eharge prior to it~ lo~di~g
into the ~urnace, but it i~ al~o po~sible bo inbroduce th~m l~to
the '~UI~aCe by individu~l layers.
'rhe charge ~meltin~ i~ conduc~ed in ~ ~u~nace where a
quartæ la~er 0.3 to 1.5 m hi~h ~i~ provided ~mmediately above
11 5B05 1
the tuyeres. The te.rm "quartz layer" should be understood as
a bed consisting primarily of quartz, as well a~ of a small
amount of limestone, slag, and ~ulfides. Initlally, the fur-
nace can be put into operation by any of the common methods,
and, when the furnace is about to reach the normal smelting
conditions~ a quartz layex of the indicated height is provided
by feeding and smel-ting a charge contai~ing an excess amount
o~ guartx in cornparison to the calculatled quartz content in
the normal working chargeO The total amouIlt o~ quartz to be
int:roduced intio the furnace, when it i~3 nearing the rlormal
smelting conditions to provide a quartz layer o~ a specified
height, is calculated on the basis of the cross section area
and the bulk weight of quartz. The height of the quartz layer
should be within a range of 0.3 to 1~5 m. These values are
cho-se~ because, when the quartz layer is less than 0.3 m,
the ratio of concentratio~ decreases below the required level,
and when ths quartz layer is more than 1.5 m thick, the norrnal
process operation is disturbed.
In accordance with the sald invention the sulfide material
smelt~ng is conducted with oxygen-enriched air blowi~g introdu-
ced into the furnace through tuyeres. ~he blow rats is 900 to
1,200 m3/tonne of sulfide raw material. The oxygen content in
the blow i8 25 to 45%. With an o~en consumption o~ le~ than
300 r~3~torme of sulride raw materlal low grade matte i8 produ-
ced~ ~nd wh~n ~he oxygen consump~ion ls lncrea~ed to over 400
m3/to~ne vf 9ul~ide ra~ material, there would b~ an axc~ss o~
oxygen that i~ not cle~ira~l~, because at ~he higher lavel~ ~f
-- 10 --
13L5605~
the furnace it oxydiæes elemental sulfur, formed as a result
of hlgher sulfide dissociation, whereby the normal process
conditions are d~sturbed~ The recovery of elemental ~ul*ur i~
therefore lower.
Liquid products obtained as a result of the smelting pro-
ces~ are separated in a forehearth into matte and slag. The
off-gases leaving the furnace are sub~ected to dust collection
and transferred ;nto a condenser for the recover~ of elemental
sulfur. After the ~e-paration of elemental sulfllr the off-gases
can be utllized for sulfuric acid manufacture or for additional
recovery of elemental sulfur by the means of S02 reduction. The
desulfurization rate reaches 95~ during the smelting. The reco-
very of elemental sulfur~ when smelting -pyritic oreAs amounts up
to 45%. Using the said method a ratio of concentratlon of 30:1
can be achieved. ~his means that e~en smelting low-grade ores
(for example, copper ores w~th a copper content of 1.5 to 2%)
can produce high-grade matte (25 to 40% copper) that does not
require additional smelting prior to the converting, ln o~her
words, the produced matte is tra~sferred directl~ for further
processing in converters. Slags obtained as a resul~ of treat
ing sulfids raw materials by the said method are normally con~
sidered to be discard slags. A characteri~tic feature of pro-
duced ~lag~ i~ the ~act th~t they have practicall~ ~o or ve~
low (up t~ 5%~ co~tent of magnetite. When qmelting copp~r zlnc
materialt th~ obtained sl~g can be used :~or the recovery of
æinc the~e-rrom, ~or example, b~ slag~uming metbod~ Slag~ ob~
t~ined whe~ ~meltin~ copper-nlckel material can be ~ub~ect~d
to ~laK-clea~ing, Xor e~ample, i~ an ~lectric furna~e.
115~
Hi~h pxoce~ values could be attained by virtue of the
ox~ygen-enriched ai:r blowing with oxygen consumption within
the ~pecifie~ range. The quartz layer o~ an appropriate height
prevents an excessive increase of the smelting productivity
and thereby it contribute~ to the higher ratio of concentra-
tion due to the intensification of the iron sulfide oxidation
by oxygen in the air blow in the presence of quartz.
By virtue of the nature o~ the said in~ention malfunctions
of the smeltin~ process can be readily corrected by controll-
ing -the ox~gen consumption which should be maintained withi~
the ~L)ecified range.
In one o~ the embodiment~ of the said invention a carbona-
ceous reductant, e.g. natural gas~ coke, fuel oil, or another
suitable red~ tant, is introduced into the blast fur~ace to
improve the elemental sulfur recovery. In the reductio~ zone of
the furnace, S02 formed in the oxidizing zone a~ a resul~ o~
iron sulfide oxidation on the quartz layer is reduced to ele-
oDfS~ CC~
ental sulfur. As it has been stated, there i8 ~ clLc;~L~nooxygen in the zone where reductant is introduced, because oxygen
ha~ been consumed in the oxidat~on zone. If n~tural ga~ is used
a~ reducta~t, its consumption i8 60 to 70 m3/tonne of sulflde
raw material and it should be supplied into thc furnace at a ra-
te o~ 36 to 73 m/~ec. Gas is supplied through noæzles located
above th~ tuyeres into a zone where practi~all~ no oxygen i~
pre~nt~ becauso it ha~ be~n completely ~pent to react wi-th
lro~ ~ul~lde~ ~here~or~, combu~tion o~ natur~l ~as in the ~ur-
n~ce cannot ta~e place and the proce~ r~mflln3 autogenou~, The
lL 15~5 1
rnentioned gas injection rate range is determined by the fact
that a-t rates lower than 36 m/sec the recovery o~ elemental
sulfur decreases to some extent, because of a nonunlform dis-
tribution of gas throughout the furnace. At rates over 73 m/sec,
the recovery of elernental sulfur alsv decreases because some
gas passes through the -furnace unreacted. UIhen smelting pyri-
raw material and using natural gas as reductant, the recovery
of sulfur in the e~Inental form, amounts to 57 to 59%.
'~/h¢n coke, preferably of a si%e -25 ~10 mm, is u~ed a~
rcductant~ its consumption i~ abollt 6-7~o of the total charge
welght. Coke is fed in-to the furnace together with the charge.
~n this case the process is as well autogenous, because the
amount of coke is equal to the stoichiometric amount required
only for the S02 reduction. The recovery of sulfur in the ele-
mental ~orm, u!hen ~melting pyritic ra~ materials~ i9 65 to
67%
be
The said method can used for processing various types of
sulfide materials, e.g. copper pyrite ores, copper-nickel pyr-
rhotite ores, copper, pyrite and pyrrhotite concentrates, cop-
per-zinc ores and middlings. On the other hand, the conventio-
nal blast furnace smelting proce~ses are not applicable to all
type~ o~ sul~ide materials. Among other thing~, ore~ containing
over 3% %n cannot be processed by -th~ copper-and sul~ux smelt~
ln~ process. ~o~eover, the said inv~ntlon can be aoplied to
low-grade p~ritic material~ rO~ q~.ample, pyrite concentrates,
containin~ pr~ciou~ metals. It pr~vides h~rewith a su~icie~tl~
hi~h recovery o~ metal~ into matte. At present lo~grade pyri-
13 -
11 ~605 I
tic raw materials are used for sulfuric acid manufacture; and
the precious metal~ con-tained report with calcines and are not
recovered in most case~, because of high processing costs.
A comparison o~ the said sul~ide material smelting method
with the conventional copper-and-sulfur smelting~ that also
provides reco~ery oP metal into matte and recover~ of eleme~-
tal sulfur, shows that th~ said method is commerclally supe-
rior because it h~ the f'ollowing advanta~e~. 'rh~ ~aid process
i5 autogenous~ i.e. -lt does not i,nvolve the u~e of carbonaceous
fuel. It allows to save 25 to 30 kg of coke per 1 tonne o~ sul-
fide material treated. The ~aid method allows to treat low-
-grade ores (e.g., ores containing 1.5 to 2% Cu) and produce
suf~iciently high-grade mattes (25 to 40% Cu) that can be used
immed~ tely for converting and thus upgrading smelting is elimi-
nated. The total sulfur recovery from pyritic raw material~
treated by the said method is 85 to 90% or more, and that from
pyrrhotlte materials i8 70 to 75% or more. A considerable part
of sulfur ls recovexed a~ elemental sulfur. The off-gases after
elemental sul~ur collection contain -~rom 8 to ~5% S02 and can
be used for sulfuric acid m'anufacture, Thus, sul~ur-bearing gas
emls~io~ into the atmosphere ara practically eliminated. ~his
makes the sflid method advanta~eou~ ~rom the point o~ view o~
the envi~onment protec-tion as w~ll.
Fro~ the mentionecl ~ac-ts it ~ollows that tho said inve~-
tion allow~ one to substantlal'ly recluce the co~ts o~ ~ulfid~
material processing duo to th~ eli~ination of :~uel requirements
and up~ra.ding ~meltin6: it en~3ure~ a high ~ul~ur recover ~rom
-- ~4 --
l ~6as ~
~u1fide rnatorial~ and eliminates deleterious emisslon~ into th~
atmosphere.
~ `or better understanding of the said in~entlon ~ome example~
of specific embodiment~ are given.
Example 1
The smelting of a charge was conducted in a blast furnace,
having a capacit~ of 70 to 100 tonnes of charge per da~, with
a hermetically sealed throat, a quart~ layer 0.45 to 0.55 m
high was provided immediately above the~ tuyeres. 'rhe charge
had the following compositio~ copper pyrite ore (1.93%
Cu, 41.5% Fe, 46.1% S) 65.8; quartz 23.7; llmestone 10.5. The
quartz ~ yer was provided, when the furnace was about to reach
the normal working conditions by feeding charge higher in
quartz than the calculated charge composition. ~he smelting
process was conducted blowing air enriched to 28~o oxygen. The
blow rate was about 1,100 m3/tonne o~ ore, the oxygen consump-
tion herewith was about 300 m3/tonne of ore. ~iquid smelting
products were separated into matte and slag in a forehearth.
The sulfur-bearing off~gas at a temperature of 380 to 440C
wa~ transferred, aft0r cleaning, into a condens~r for elemental
sulfur separat~on. The recovery of sulfur in the elemental form
wa~ 41.7%. The desul~urization rate was 90.5%. The off-gas after
~ulur condensation contained ~%): 22.4 S02, 0.15 H2S, 0.16 COS,
5.0 C02, 0.2 C0 and -9 2~ the balance wa~ nytro~en. Such a ga~
could be utiliz~d *or 3ulfuric acid manufac~ure or for additio~
n~l ~lem~ntal sulfur recov~ by reduction. ~ke ratio of con-
contration wa~ 8:1. 'rhe produced mattfl8 conkained 22~8% CU
- 15
1 15~0~
and were subjected directly to converting for copper recove~y~
The proAuced slags contalned 0,24~ Cu and were discarged~ The
silica, iron, and calci~n oxide content3 in sl~g~ wer~
35 40~ 34-39 6-9, respectively; there was practically no magne-
tite in ths slags.
Example 2
Smelting of the charge, ~ ving the analysis as in Example
1, was conducted in a bl~t flurnace in the same manner as des-
cribed in ~xample 1, but the quart~ layer height was 1 to 1~2 m;
the 33% oxygen-enriched air blow rate was 1,200 m3/tonne o~ ore,
the oxygen consurnption herewith was about 400 m3~tonne of ore.
The following results were obtained. The desulfurization rate
was 95%. The recovery of sulfur in the elemental form was about
43,5%. The off-gas had the following analysi~ (%): 23.3 S02,
0.21 H2S, 0.23 COS, 5.5 C02, 0.17 C0 a~d 0.8 2~ the balance
was nytrogen. The ratio of concentration during smelting was
30.1:1, The produc,ed mattes contained 58.1% Cu. The produced
slag~ contained 0.6% Cu. As for the rest o~ the slag constitu-
ents, the slag analysis was similar to that in ~xample 1.
Thls example illustrates the extensive potential of the
said process with respect to attaining a high ratio o~ concen-
tration,
_am~
Smelting o~ the charge, havin~ the analysis as in Exa~ple
1 t ~a~ oondllctecl in a blast furnac~ in the same manner, as des-
cribed in Exarnple 1~ but the quartz layer height was 0.6 to 0.7
m; the 30% oxygen-enriched air blow rate wa~ abou~ llZ00 m3/
- 16 -
l ~560~ ~
/tonne of ore, the oxy~en concsumption herew-lth was about 360
m3/tonne of ore, to ~ncrease the sulfur recover~ in the el-em~n-
tal form, natural gas wa~ introduced into the furnace for reduc-
tion of S02 formed during the smeltin~ process, Natural ga~ wa3
fed into the ~urnace through nozzles located at a level of 0.6 m
above the tuyeres, where ~ractically no oxygen was present. The
natural gas injection rate ~as 45/sec and its consurnpt;on amount-
ed to about 63 m3/tonne of ore. The following results were obtain-
ed. The desulfurization rate was 92 8%. ~he sulfur recovery in
the elelnental form was 57.7~0. The off-ga~ had the following
analysi~ 11.6 S02, 1~33 H2S~ 1.4 COS, 9.5 C02" 1.6 C0, 1.0
2~ 0.76 H2 and 0.~'~ CH4; the balancs was nytrogen~ The ratio
of concentration ~as 15.6:1. The prod,uced mattes contained
30.1% Cu. The copper content of produced slag~ was 0,33%. As
for the rest of the slag constituents, the slag analysi~ was
similar to that in Example 1.
Example 4
Smelting process was conducted in a blast furnace in the
same rnanner a~ described in E~ample 3 with an exception that
to improve the sulfur recovery in the elemental ~or;m, instead
of natural ga~ coke wa~ added into the charge in an amount of
6.5~ of the total charge wei~ht~ The ~cllowing results were
obtained. The desulfurization rate W~5 92~5~o~ The ~ulfur reco-
ver~ in the olement~l form W9~ 65~n~ The o~f-~as h~d the fol-
lowing an~ly~is (%~ 8.9 S02, ~31 H~SI 2.2 C~S? 13.3 C02, 1J7
~0, 0~8 0~ the balanc~ wa8 n~trogen. ~ho ratio o~ concentr~-
tion wa~ 15 4~ ho proauced matte~ conb~inod ?9.7% Cu~ '~he
-- 17 --
~ 15~)S ~
copper content oî the pro(luced sLags was 0.31%~ As for the re~t
of the slag consvtmtuents, the 31ag analysi~ was ~imilar to that
in E~xample 1.
Exam 1~ le
Smelting was conducted in a blast fu~nace of the same capa-
city, as in Example 1. ~he initial raw material wa~ co~pe~zinc
pyrite ore, containing 3.55% Cu, 7% Zn, 34.5% ~e and 43.7~ S~
Into the -fu~ace provided with a qu~rt~z layer 0.3 to 0.35 m
high, charge of the followlng composition S~ copper-zinc ore
71.4, quartz 18.6, limestone 10, was fed. The smel-ting process
was carried out with 32% oxygen-enriched air blowing. The blow
rate wa~ 960 m3/tonne o~ ore, the oxygen consumption herewith
was about 300 m3/tonne of ore. ~he following result3 were ob-
tained. The desul~urization rate was 88%. The sulfur recovery
in the elemental form was about 40%. The off-gas had the fol-
lowing analysis (%): 25.2 S02, 0.1 H2S, 0.1 ~OS, 6.1 C02s 0.14
C0 and 7 2; the balance was nytrogen. ~he ratio of copper
concentration was 6.8:1. The produced mattes contained 24.1
Cu and 3.5% Zn. The slags, containing 0.28% Cu and 5.5% Zn
can be processed to recover zinc therefrom~ As ~or t;he rest o~
the slag con~tituents, the slag analysis was similflr to that in
Examp le 1.
This example is an illustration of copper-~inc ore smelt-
ing yieldin~; sati~factory results. And this is an additional
fldvanta~e of the ~aid invention/ for such an ore car~ot be pro-
cessed by th~ copper-and- sulfur smelting technique be~cause
o~ bhe hi~h zlnc contenb~
1~ --
0~1
Example 6
Smelting was conducted in a blast furnace o~ the same ca-
pacity, as in E~ample 1. The initial raw material is low-grade
pyrite ore, containing 0.5g~0 Cu, 45.4% ~e, 50.3~ S, 1.3 g~t ~v
and 6.3 g/t Ag. Into the furnace with a quartz layer 0.65 to
0.75 m high, charge, contairiing 65.6% of the said ore, 24.3~
quartz and 10.1% limestone, was fed. The smelting process was
conducted with 30 to 32% oxygen-enriched air blowing. The blow
rate was 1,1~0 m3/tonne of oret the oxygen consumption here-
with was 330 to 350 m3/to~ne of ore. The following results we-
re obtained. The desul~urization rate was about 93%. ~he sul-
:~ur recoverg in the elemental for~ amounted to about 45%, ~he
o~f-gas had the following analysis (~0): 23.6 B02, 0.11 H2S,
0.23 COS, 6.8 C02, 0.27 C0 and 0.6 2; the balance was nytro-
gen. The concentration rate was 14.2:1. The produced mattes
contained 8.4% Cu~ 12 gJt Au, 75 g/t Ag. The copper, gold and
sil~er recoverles into matte were 68.5, 79.6 and 85,7%, respec-
tively. ~he copper content of the slags produced was less than
0.2%.
~ his example illustrates processing of low-grade pyrite
raw material with a precious metals content. Under the same con-
ditions, it is possible to proces~ lumpy (e.g. brique ~d or
pelletized) pyrite concentrates.
xample 7
~ Smelting wa~ carried out in a bla~t ~urnace o~ the same
c~pacity, a~ in E,xa~ple 1. ~he initial raw material wa~ copper
concentr~te~ oont~inin~ 16~3% CU7 6.2~ Zn, ~3~ Fe~ and 36.8%
~ 19 --
115~
S. Prior to ~melting, the copper concentrat~ was form~d into
lumps, for example, by the briquetting technlqu~ in a roller
pres~ u~ing lignosulfonates ~wastes from the paper and pulp i~-
dustries) as a binding agent~ Charge, containing 66.4% bri~
quetted copper concentrate, 24.7% quartz and 8.9% limestone,
was fed into the furnace in which a guartz layer 0.9 to 1.1 m
high had been provided The smelting process was conducted
with 34% oxygen--enriched air blowing. 'rhe blow rate wa~ 900
m3/tonne of briquet-tes, the oxygen consumption herewith wa~
about 300 m3/tonne of briquette~ he following results were
obtained. The desulfurization rate was 80~2%~ lrhe elemental
3ul~ur recovery was 24~7~o~ The off-~as had the following ana-
lysi~ 16.9 S02, 0.13 ~2S, 0.18 COS, 4.4 C02, 0.15 C0 and
-~ 2; the balance was nytrogen. The ratio of concentration
was 3.7:1. The produced mattes contained 60.3% Cu and 1.5% Zn.
The slags produced contained 0,6% Cu and 5.9~0 Zn and could be
processed to recover zinc therefrom, as well as to additional-
ly recover some copper. As for the rest of the slag constituents~
the slag analysis waY similar to that in Example 1.
Smelting wa~ carried out in a blast fu~nace of the same ca-
p~city, as in ~xample 1~ 'rhe sulfide raw material to be treated
wa~ briqu~tted copper concentrate~ as in Exaraple 7. Charge o~
the ~ollowlng~ compo~ition: 63 9~ briquatte~ 26.5~ quartz and
9,G% lime~tone, was ~ed into the -~urn~ce wher~ a quartz layer
1,3 to 1~5 m hi~h had been provided. ~he smelting ~rocess wa~
conducted wi~h 35% ox~gen~enrlched air blowin~ The blow rate
20 -
1 156~5 ~
was 950 m3/tonne of briquettes~ the oxy~en consumption herewith
wa~ about 330 m3/tonne of bxiquettes. ~he ~ollowing result3 were
obtained. The desulfurization rate was 86.4~o~ The elemental sul~
fur recovery wa~ 25.2~. The off-gas had the following analysis
(%): 17.8 S02, 0.15 H2S, 0.17 COS, 4.5 C02l 0.18 C0 and 0.7 0~,
the balance was nitrogen. The ratio of concentration was 4.9:1.
The produced matte (white matte~ contained 79.5% Cu and 0~370
7,n. The produced slags contained 0.8% Cu and 5.6% Zn. A~ for
the rest of the slag constituents, the slag analysis was simi-
lar to that in Example 1. These slags could be processed to re-
cover zinc and additional copper th~refrom.
Example ~
Smelti ng is carried out in a blast furnace o~ the same
capacity, as in Example 1. The initial raw material was a pyr-
rho~ite-type copper-nickel ore, containing 4.6% Cu, 4.3% Ni7
50~o ~e and 30.3% S. Charge,consisting of 67~5~o of the said ore,
24.3% quartz and 8.2yO limestone, was fed into the furnace, whe-
re a ~uartz layer 1.1 to 1.3 m high had been provided. The smelt-
ing process was conducted with 30 to 32~o oxygen-enriched air
blowing. ~r~e blow rate wa~ 1,000 lD3/tonne of ore, the oxygen
consumption herewith amounted to about 300 to 32 m3/tonne of ore.
The ~ollowin~ result~ were obtained. ~he de~ul~urization rate
was 80.6%. The elemental sulfur recovery was about ll~o. The of~-
-ga~ had the following analysis t%): 16 S02, 0.1 ~2S~ 0.1 COS,
5 .1 co2 ~ o~ 1 ca and 5 2- The ra-tio of concentration ~or -the
total mebal~ cont~n-t w~ 4074 1~ rrhR produc~d matte~ containRd
24.4% Cu and 17.8% Ni. ~he ~lags con~ained o.~a~ Cu and 0,28% Ni.
_ 21 --
1 ~S~05 1
As for the re~t of the slag constituents, the slag analysi~ wa~
~imilar to that in Exa~ple 1, except Eor magnetite of which 4 to
5% was contained in the said slags. It i~ possible to carr~ out
~lag cleanin~, especially for nickel recover~. Thus~ the reduc-
tion and sulfidiæation slag cleaning in an electric furnace en-
sured a decrease in copper down to 0.1'7~ and in nickel down to
0.1% or less. Beside~ the ~lag cleaning proce~s can be accom-
pli~hed at a significantly higher rate and with lower energy
consumption than for slag cleaning following other autogenous
proce~ses. This is attrihutable to the lower (not more than 5%)
rnagnetite content in the obtained.
In ~xam,E)le~ ~ through 9~ the produced Mattes are transferr-
ed directly to converting for further processing,
For comparison, results of copper pyrite ore treatment by
the copper-and-sul~ur smeltin~ process in accordance with US
Patent N 1,860,585 are given below. The charge consisted of
80.8% ore (containing 2.66% Cu, 38.5% ~e and 42,64% S), 11.5%
quartz. 2,7% limestone and 5% of recycled slag. The smelting of
this cha~ge with a coke addition of lO~o of the total charge
wei~ht was conducted in a blast ,furnace with a hermetically seal-
ed throat at an air blow rate of 950 m3/torme of ore. The follow~
ing re~ult~ were obtained. The des~lfurization rate was 85.18%~
The ratio of concentration was 5.5:1. The mattes produced con-
tained 14~6% Cu and were -treated in a ~imilar bla~t ~urnace with
fl ~eal~d khroat to prOdUG~ l~ ttes with a copper cont,qnt of 40 to
50%, c)uitable -ror ~ub~;equent con~erting. ~he copper con~ent o~
- ~2
1 ~5~5 ~
~lags produced during ore s~elting wa~ 0.4%. A part o~ coke
fed lnto the fl~rnace wa~ consumed for the S02 reduction, and
another part passed down to the bottom o~ the :~urrlace and con-
sumed oxygen supplled by air blowing, i.e. it behaved as fuel.
-- 23 --
