Note: Descriptions are shown in the official language in which they were submitted.
HENKEL KGaA ~ 8
Dr. Fb/28
22nd May, 1990
Patent Application
D 9130
Proce~ for the recovery o~ mineral~ from non-qulfidic
ores bY flotation
This invention relates to a process for the recovery
of minerals from non-sulfidic ores by flotation, in which
esters of dicarboxylic acids with fatty acid monoal~anol-
amides, optionally in admixture with other anionic or
nonionic surfactants, are used as collectors.
Flotation is a separation technique commonly used in
the dressing of mineral ores for separating valuable
minerals from the gangue. For flotation, the ore is sub-
jected to preliminary size-reduction, dry-ground, but pref-
- 10 erably wet-ground and suspended in water. A collector is
then added, often in conjunction with other reagents, in
cluding frothers, regulators, depressors, (deactivators)
and/or activators, in order to facilitate separation of the
valuable minerals from the unwanted gangue constituents of
the ore in the subsequent flotation process. These re-
agents are normally allowed to act on the finely ground ore
for a certain time (conditioning) before air is blown into
the suspension to produce a foam at its surface and to
start the flotation process. The collector acts as a
hydrophobicizing agent on the surface of the minerals,
causing the minerals to adhere to the gas bubbles formed
durinq the aeration step. The mineral constituents are
selectively hydrophobicized so that the unwanted constitu-
ents of the ore do not adhere to the gas bubbles and remain
behind while the mineral-containing foam is stripped off
and further processed. The object of flotation is to
D 9130 2 2~
recover the valuable mineral of the ores in as high a yield
as possible while at the same time obtaining high enrich-
ment of the valuable mineral.
Anionic or cationic surfactants are mainly used as
collectors in the flotation of non-sulfidic ores. Their
function is to adsorb selectively on the surface of the
valuable minerals to ensure high enrichment in the flota-
tion concentrate. In addition, the collectors are intended
to develop a stable, but not excessively stable flotation
lo foam.
In many cases, however, the collectors frequently used
in the flotation of non-sulfidic ores, such as for example
fatty acids or alkyl sulfosuccinates tAufbere~tungstec~ni~,
26, 632 ~1985)~, lead to unsatisfactory recovery of the
valuable minerals when used in economically reasonable
quantities.
Accordingly, the problem addressed by the present
invention was to provide collectors having improved proper-
ties to make the flotation process more economical.
The present invention relates to a process for the
recovery of minerals from non-sulfidic ores by flotation,
in which ground ore is mixed with water to form a suspen-
sion, air is introduced into the suspension in the presence
oS a collector system and the foam formed is stripped off
together with the floated solids present therein and in
which esters of dicarboxylic acids with fatty acid mono-
alXanolamides corresponding to one of formulae ($) to (VI)
below
Rl-CO-NH-C~2-C~R2-O-CO-~CH2),-COOX tI)
Rl-CO-NH-CH2-C~R2-O-CO-CH=CH-COOX ~II)
D 913 0 3 ~,~ 8
Rl-C0~ CH2-CaR2-0-CO-C~_.C-COOX ~III)
CH3
Rl-CO-NX-CHz-CHR2-O-CO-7=CH-COOX ~ IV)
c~3
Rl--CO-N~-ClIz-CH~2-O-CO-C}12-C-COOX ~V)
CH2
Rl--CO~ C~I2-CNR2-O-CO-C-CH2-COOX ~VI )
Il
CH2
in which Rl-Co is an acyl radical containing 6 to 22 carbon
atoms and 0, 1, 2 or 3 double bonds, R2 is hydrogen or a
methyl group, m is a number of 1 to 10 and X is hydrogen,
an alkali metal or an ammonium ion,
are used as collectors.
In the context of the invention, non-sulfidic ores are
understood to be salt-type minerals, for example fluorite,
scheelite, baryta, apatite, iron oxides and other metal
oxides, for example the oxides of titanium and zirconium,
and also certain silicates and alumosilicates.
The esters of dicarboxylic acids with fatty acid mono-
alkanolamides are known substances which may be produced by
the relevant methods of organic synthesis. One suitable
method for their production comprises, for example, react-
ing dicarboxylic acids, dicarboxylic acid monoesters or di-
carboxylic anhydrides with fatty acid monoalkanolamides.
The production of the esters t S also described in GB
61S,66S, CH 2~8 209, C~ 256 76~ and D~-A-3S 06 838.
Malonic acid, fumaric acid, pimelic acid, suberic
acid, azelaic acid, sebacic acid, undecanedioic acid or
dodecanedioic acid are suitable dicarboxylic acid compo-
nents for the production of the esters used in the process
D 9130 4 ~ ~ 5~ 8
according to the invention. Esters distinguished by par-
ticularly advantageous properties in the process according
to the invention are obtained on the basis of maleic acid,
succinic acid, glutaric acid, adipic acid, citraconic acid
or itaconic acid and mixtures of these acids with one
another.
The amide component may be selected from fatty acid
monoalkanolamides corresponding to formula (VII)
Rl--CO-NH-CR2-CH22-OH ~VII)
in which R1-CO and R2 are as defined above. The acyl group
R1-CO may be derived, for example, from caproic acid, capry-
lic acid, capric acid, lauric acid, myristic acid, palmitic
acid, palmitoleic acid, stearic acid, oleic acid, elaidic
acid, petroselic acid, linoleic acid, linolenic acid, gado-
leic acid, arachidonic acid, behenic acid or erucic acid.
As usual in oleochemistry, the fatty acids on which the
fatty acid alkanolamides are based may also be present in
the form of technical mixtures of the type obtained, for
example, in the pressure hydrogenation of natural fats and
oils, for example coconut oil, palm oil, palm kernel oil,
rapeseed oil, sunflower oil or beef tallow. By contrast,
the alkanolamine group is derived from monoethanol-1,2-
amine or monopropanol-1,2-amine. Esters distinguished by
particularly advantageous properties in the process accord-
ing to the invention are obtained on the basis of fatty
acid moncalXanolamides in which Rl-CO represents acyl radi-
cals containing 12 to 18 carbon atoms or 0 or l double bond
and RZ is hydrogen.
The process according to the invention enables the
esters of dicarboxylic acids with fatty acid monoalkanol-
amides to be used as collectors for the recovery of miner-
als from non-sulfidic ores by flotation either on their own
or in the presence of other anionic or nonionic surfac-
D 9130 5 2~
tants.
In the context of the invention, anionic surfactants
are fatty acids, alkyl sulfates, alkyl ether sulfates, al-
kyl sulfosuccinates, alkyl sulfosuccinamates, alkyl benzene
sulfonates, alkyl sulfonates, petrol sulfonates, acyl lact-
ylates, sarcosides, alkyl phosphates and alkyl ether phos-
phates. All these anionic surfactants are known compounds
of which the production - unless otherwise stated - is de-
scribed, for example, in J. Falb-, ~. Ha~serodt ted.),
"~atalysatoren, ~onside un~ Mi~er~lol~d~itive", Thiems
Verlag, 8tuttgart, 197~ or J. Falb- (ed.) "8urfactant~ in
Con~umer Pro~ucts~, 8pringer Verl~g, Berlin, 1986.
Suitable fatty acids are, above all, the linear fatty
acids corresponding to formula (VIII)
R3-Cooy (VIII)
in which R3 is an aliphatic hydrocarbon radical containing
12 to 18 carbon atoms and 0, 1, 2 or 3 double bonds and Y
is an alkali metal, alkaline earth metal or ammonium ion,
which are obtained from vegetable or animal fats and oils,
for example by lipolysis and optionally fractionation and/
or separation by the rolling-up process. Particular signi-
ficance is attributed in this regard to the sodium and
potassium salts of oleic acid and tall oil fatty acid.
Suitable alkYl sulfates are the water-soluble salts of
sulfuric acid semiesters of fatty alcohols corresponding to
formula ~
R~-O-8O3Z (IZ)
in which R~ is a linear or branched alkyl radical containing
8 to 22 and preferably 12 to 18 carbon atoms and Z is an
alkali metal or ammonium ion.
Suitable alkYl ether sulfate~ are the water-soluble
D 9130 6 Z~ 18
salts of sulfuric acid semiesters of fatty alcohol polygly-
col ethers corresponding to formula ~)
R -~OC~2CH~O~O3Z ~X)
R~
in which R5 is a linear or branched alkyl radical containing
8 to 22 and preferably 12 to 18 carbon atoms, R5 is hydrogen
or a methyl group, n is a number of 1 to 30 and preferably
2 to 15 and Z is as defined above.
Suitable 31~Yl sulfosuccinates are sulfosuccinic acid
monoesters of fatty alcohols corresponding to formula ~XI)
R7-ooC-C~2-CR-Cooz ~XI)
S032
in which R7 is a linear or branched alkyl radical contain-
ing 8 to 22 and preferably 12 to 18 carbon atoms and Z is
as defined above.
Suitable alkyl sulfosuccinamates are sulfosuccinic
acid monoamides of fatty amines corresponding to formula
R8-NH-OC-CR2-CR-COOZ ~XII)
~o3~
in which R8 is a linear or branched alXyl radical contain-
ing 8 to 22 and preferably 12 to 18 carbon atoms and Z is
as defined above.
Suitable alkyl benzene sulfonates are compounds corre-
sponding to formula ~XITT)
R~-Cd~-8O3~ (XIII)
D 9130 7
in which R9 is a linear or branched alkyl radical containing
4 to 16 and preferably 8 to 12 carbon atoms and Z is as
defined above.
Suitable alkvl sulfonates are compounds corresponding
to ~XIV)
R1-80~Z ~XIV)
in which R10 is a linear or branchad alkyl radical contain-
ing 12 to 18 carbon atoms and Z is as defined above.
Suitable Detrol sulfonates are compounds obtained by
reaction of lubricating oil fractions with sulfur trioxide
or oleum and subsequent neutralization with sodium hydrox-
ide. Particularly suitable petrol sulfonates are products
in which the hydrocarbon radicals predominantly have chain
lengths of 8 to 22 carbon atoms.
Suitable acvl lactvlates are compounds corresponding
to formula ~V)
Rll-CO-O-C~-COOZ ~gV)
I
CH3
in which R~1 is an aliphatic, cycloaliphatic or alicyclic,
optionally hydroxyl-substituted hydrocarbon radical con-
taining 7 to 23 carbon atoms and 0, 1, 2 or 3 double bonds
and Z is as defined above. The production and use of acyl
lactylates in flotation is described in DE-A-32 38 060.
Suitable sarcosides are substances corresponding to
formula ~XVI)
CH3
Rl2-CO-N-C~2-COOH ~ XYI: )
~ 3~
D 9130 8
in which R~2 i9 an aliphatic hydrocarbon radical containing
12 to 22 carbon atoms and 0, 1, 2 or 3 double bonds.
Suitable alkyl ~hosphates and alkyl ether phosphates
are compounds corresponding to formulae ~XVII) and ~XVIII),
Rl3- ~OCH2CH2) pO O
p ~YVII)
10 R~ OClI2CH2) qO 02
and
Rl3-~ocH2cH2~po O ~XVIII)
\
/ \
ZO OZ
in which R~3 and Rl~ independently of one another represent
an alkyl or alkenyl radical containing 8 to 22 carbon atoms
and p and q are 0 in the case of the alkyl phosphates and
a number of 1 to 15 in the case of the alkyl ether phos-
phates and Z is as defined above.
If the dicarboxylic acid N-alkyl monoamides are used
in admixture with alkyl phosphates or alkyl ether phos-
phates, the phosphates may be present in the form of mono-
or diphosphates. In this case, mixtures of mono- and di-
alkyl phosphates of the type obtained in the industrial
production of such compounds are preferably used.
In the context of the invention, nonionic surfactants
are understood to be fatty alcohol polyglycol ethers, alkyl
phenol polyglycol ethers, fatty acid polyglycol esters,
; fatty acid amide polyglycol ethers, fatty amine polyglycol
ethers, mixed ethers, hydroxy mixed ethers and alkyl glyco-
sides. All these nonionic surfactants are known compounds
of which the production - unless otherwise stated - is
described in J. Falbe, U. Hasserodt (ed.), "Katalysatoren,
i
:.,
s~
D 9130 9
Tenside und Mineraloladditive", Thieme Verlag, Stuttgart,
1978 or J. Falbe ~ed.) "Surfactants in Consumer Products",
Springer Verlag, Berlin, 1986.
Suitable fatty alcohol ~olvqlycol ethers are adducts
of on average n mol ethylene and/or propylene oxide with
fatty alcohols corresponding to formula ~XIX)
R~5~oc~2lCH~ DO~ (~IX~
1 0 }~,6
in which Rl5 is a linear or branched alkyl radical contain-
ing 8 to 22 and preferably 12 to 18 carbon atoms, R6 is
hydrogen or a methyl group and n i5 a number of 1 to 30 and
preferably a number of 2 to 15.
Suitable alkvl Dhenol ~olvalvcol ethers are adducts of
on average n mol ethylene and/or propylene glycol with
alkyl phenols corresponding to formula (XX)
Rl6-C6H~-(OC~2C~)DOH (XX)
a6
in which R16 is an alkyl radical containing 4 to 15 and
preferably 8 to 10 carbon atoms and R6 and n are as defined
above.
Suitable fattv 3~ polyqlvcol esters are adducts of
on average n mol ethylene and/or propylene oxide with fatty
alcohols corresponding to formula (XXI)
R17-Co ( OC~2CII ) DO~I (XXI)
~,6
in which Rl7 is an aliphatic hydrocarbon radical containing
5 to 21 carbon atoms and 0, 1, 2 or 3 double bonds and R6
and n are as defined above.
~3 ~
D 9130 10
Suitable f~y acid amide ~olYalvcol ethers are
adducts of on average n mol ethylene and/or propylene oxide
with fatty acid amides corresponding to formula ~XXII)
Rl8-CO-NH~OCH2CH)nO~
R~
in which R~8 is an aliphatic hydrocarbon radical containing
5 to 21 carbon atoms and 0, l, 2 or 3 double bonds and R6
and n are as defined above.
Suitable fatty amine Dolyalvcol ethers are adducts of
on average n mol ethylene and/or propylene oxide with fatty
amines corresponding to formula ~XII$)
R18~ OCH2CH ) DOll (X~
R6
in which R19 is an alkyl radical containing 6 to 22 carbon
atoms and R6 and n are as defined above.
Suitable mixed ethers are reaction products of fatty
alcohol polyglycol ethers with alkyl chlorides correspond-
ing to formula ~XXIV)
R2o-~oc~2cH)n-o-Rzo ~XXIV)
R~
in which R20 is an aliphatic hydrocarbon radical containing
6 to 22 càrbon atoms and 0, 1, 2 or 3 double bonds, RZ i~
an alkyl radical containing 1 to 4 carbon atoms and R6 and
n are as de~ined above.
Suitable hvdroxy mixed ethers are compounds corre-
sponding to ~or~ula ~X~V)
R2l-C~~C~ OC~2C~I) n--O-R22 ~V)
OH R~
a
D 9130 11
in which RZl is an alkyl radical containing 6 to 16 carbon
atoms, R22 is an alkyl radical containing 1 to 4 carbon
atoms and R6 and n are as defined above. The production of
the hydroxy mixed ethers is described in German patent
application DE-A-37 23 323.
Suitable alk~l alvcosides are compounds corresponding
to formula ~rvI)
R23-o-~G)~ ~XXVI)
in which G is a symbol for a glycose unit derived from a
sugar containing 5 or 6 carbon atoms, x is a number of 1 to
10 and R23 is an aliphatic hydrocarbon radical containing 6
to 22 carbon atoms and 0, 1, 2 or 3 double bonds. G is
preferably a glucose unit and x is a number of 1.1 to 1.6.
The production of the alkyl glycosides is described, for
example, in German patent application DE-A-37 23 826.
If the esters of dicarboxylic acids with fatty acid
monoalkanolamides are used in admixture with other anionic
or nonionic surfactants rather than on their own, these
mixtures advantageously contain 5 to 95S by weight and
preferably 10 to 60% by weight of the ester.
To obtain economically useful results in the flotation
of non-sulfidic ores, the surfactant mixture has to be used
in a certain minimum quantity. At the same time, however,
a maximum quantity of the surfactant mixture must not be
exceeded either because otherwise foaming would become
excessive and selectivity with respect to the valuable
minerals would diminish.
The quantities in which the esters or their mixtures
with other anionic or nonionic sur~actants in the context
of the invention are used are determined by the type of
ores to the floated and by their content of valuable
minerals. Accordingly, the particular quantities required
may vary within wide limits. In general, the esters to be
D 9130 12
used in accordance with the invention or mixtures thereof
with anionic or nonionic surfactants are used in quantities
of 50 to 2,000 g and preferably in quantities of 100 to
1,500 g per tonne crude ore.
The process according to the invention also includes
the use of typical flotation reagents such as, for example,
frothers, regulators, activators, deactivators, etc. The
flotation process is carried out under the same conditions
as state-of-the-art processes. In this connection, the
following literature references are cited as technological
background in the processing of ores: H. 8chubert, "Aùf-
bereitung fester mineraliscber 8toffe", Lo~pzig, 1967: D.B.
Pu¢haJ tEd.)~8olid/Liguid 8epar~tion ~quipment 8cale-up~,
Croydon, 1977t ~.8. Perry, C.J. VanOss, ~. Grush~a (~
"8eparation and Purification Mstho~s", New Yor~, 1973 -
1978.
The process according to the invention is preferably
used for the flotation of salt-type minerals, more particu-
larly apatite ores.
The following Examples are intended to illustrate the
invention:
- Ex~mples
I. Collectors and oo-collectors used
A) Collectors Al) maleic acid/oleic acid monoethanol-
amide ester, Na salt
A2) itaconic acid/oleic acid monoethan-
olamide ester, Na salt
A3) C,~ dicarboxylic acid/oleic acid
monoethanolamide ester, Na salt
A4) maleic acid/stearic acid monoethan-
olamide ester, Na salt
D 9130 13
B) Co-collectors 81) alkylsulfosuccinate-Na/NH,salt based
on maleic acid mona-oleyl/cetyl
1) ester
B2) technical oleic acid
iodine value 95, Edenor A-Tio5
(crude), Henkel KGaA
C) Depressor Cl) phenol-formaldehyde condensate
Suspendol~PPK, Henkel KGaA
II. Preparation of the collo¢tors accordinq to the ~nven-
tion
,
Prepar~tion of maleic acid/ol-ic aci~ mono-thanolam~e
~t-r, N~ 8~1t ~A1)
200 g (0.6 mol) oleic acid monoethanolamide are intro-
duced into and heated to 90-C in a 500 ml three-necked
flask equipped with a stirrer, internal thermometer and
reflux condenser. 62 g (0.63 mol) maleic anhydride were
introduced into the melt in portions and the reaction mix-
ture was stirred for 90 minutes at 95-C. Thereafter,
potentiometric determination with sodium hydroxide revealed
a residual content of unreacted anhydride of approximately
2.5% by weight. 120 g of the acidic ester obtained were
then dissolved with 11.5 g sodium hydroxide in a mixture of
100 ml water and 60 ml ethanol, followed by stirring for 60
minutes at 80-C. Finally, the solvent was distilled off at
80-C/20 mbar. 129 g of the sodium salt of the ester were
obtained in the form of a yellow solid.
Preparatlon of ltaconio acld/oleic acid mo~oethanolamide
~ter, Na s~lt ~a2 )
Al was repeated using 70 g (0.63 mol) itaconic an-
hydride. The Na salt was obtained in the form of a brown
solid.
zr~3~8
D 91~0 14
Pr-paration o~ C~icarboYylic acid/ol-ic aci~ nono-thanol-
aoi~- est-r, Na ~alt ~A3)
28.1 g (0.08 mol) oleic acid monoethanolamide, 14.6 g
(0.1 mol) of a technical C,~ dicarboxylic acid monomethyl
ester mixture (succinic acid/glutaric acid/adipic acid
ester = 1 : 1 : l, Rhone-Poulenc) and 0.25 g methanolic
sodium methylate solution (30% by weight) were introduced
into a 250 ml distillation apparatus and reacted at 96-C/2S
mbar, methanol being continuously distilled off. 0.25 g
sodium methylate solution was added after S h and after 7
h. After a total of 13 h, the reaction was terminated.
The crude esterification product was then saponified with
sodium hydroxide solution for 2 h at 96 C.
lS Preparation of mal-ic aci~/~tearic acid monoethanolamido
est-r, Na salt ~a~)
Al was repeated using 200 g (0.6 mol) stearic acid
monoethanolamide. The reaction was carried out at 10S-C.
The crude reaction product had a residual anhydride content
of 4% by weight. Neutralization was carried out in the
same way as described in Al).
III. Plotation te~ts in a Denver cell
Examples l to 5: ComDarison Example l:
~lotation of apatit- or-
The flotation batch was a low-grade apatite ore con-
taining a high percentage of siliceous gangue and having
the following composition (based on the principal constitu-
ents):
P20, : 4% by weight
sio2 : 38% by weight
CaO : 10% by weight
MgO : 16% by weight
'
D 9130 15 ~J~ A8
The flotation batch had the following particle size
distribution:
- 40 ~m : 20.8% by weight
40 - loo ~m : ls.o~ by weight
loo - 200 ~m : 29.1% by weight
200 - 500 ~m : 26.5% by weight
> 500 ~m : 4.6~ by weight
The collectors according to the invention were used on
their own or in combination with an alkyl sulfosuccinate
Na/NH4 salt (B1) or a technical oleic acid (B2) as co-
collectors, the collector and co-collector being mixed in
a ratio of 50 : 50 to 70 : 30 parts by weight. A technical
oleic acid dissolved with sodium hydroxide solution was
used for comparison.
In the rougher flotation step, the ore was floated in
a Denver type Dl 2 liter laboratory flotation cell, the
cleaning stages (2 to 4 scavengings) being carried out in
a corresponding l liter cell. Water having a hardness of
3~d (d = German hardness) was used as the flotation water;
the pulp density during rougher flotation was approx. 500
g/l. A phenol-formaldehyde condensate (Cl) was used as
depressor in a quantity of 200 g/t. The pH value of the
pulp was ad~usted to pH 10 with sodium hydroxide.
The reagents were conditioned with stirring at a speed
of 1,000 r.p.m., the conditioning time being 5 minutes both
for depressor and for collector. Flotation was carried out
at a speed o~ l,lO0 r.p.m. (2 liter cell) or l,000 r.p.m.
(1 liter cell). The flotation time was approximately 4
minutes during which the flotation froth was stripped by
hand.
In the cleaning flotation stages, the rougher concen-
trate was introduced into the 1 liter cell in the absence
of reagents and floated for approx. 4 minutes at l,OOo
D 9130 16 ~33~8
r.p.m. Example 1 and Comparison Example 1 were carried out
with four cleaning stages while Examples 2 to 5 were
carried out with two cleaning stages. The results are
summarized in Table 1.
Examples 1 to 5 show that, where the esters are used
as collectors in the context of the invention, a higher
recovery of P20s can be obtained than with the standard
collector, oleic acid, for the same dosage. Where the
esters are combined with standard collectors, an increase
in selectivity with respect to the valuable minerals is
observed, so that less cleaning stages are required to
obtain marketable mineral concentrates.
Table 1:
- Flotation of low-grade apatite ore in a Denver cell;
percentages as % by weight
Ex- Collector OU FS B C1 ~ NC
ample
g/t % % % %
,
1 Al 150 rt73.7 0.18 4 4
ct12.3 0.86 3
conc 14.024.44 93
2 Al (50% by weight) 120rt 81.5 0.30 6 2
B2 (50% by weight) ct 10.9 5.74 16
conc 7.635.51 68
. :
D 9130 17
Table 1: (continued)
Flotation of low-grade apatite ore in a Denver cell:
percentages as % by weight
Ex-Collector OU FS R Cl ~B NC
ample
g/t % ~ % %
3A2 (50% by weight)120 rt80.3 0.19 4 2
B2 (50% by weight) sc4.4 2.42 3
ct7.6 5.61 12
for sc: S0 conc7.736.39 81
lS 4A3 (50% by weight)120 rt81.10.26 6 2
B2 (50% by weight~ sc2.9 4.13 4
ct7.9 3.87 9
for sc: 30 sc8.134.38 81
5A4 (70% by weight)213 rt83.60.34 8 2
81 (30% by weight) ct6.3 2.02 3
conc10.131.9289
Cl B2 142 rt72.80.37 8 4
ct14.61.31 5
conc12.624.2187
Legend: QU s quantity of collector used, based on the
ore
FS ~ flotation stage
R = recovery
C1 = P20, content
PR = P205 recovery
NC - number o~ cleanings
rt = rougher flotation tailings
D 9130 18 ~ 8
ct = tailings of the cleaning stage
sc = scavenger flotation
scavenging of the rougher flotation
tailings in a scavenging cell
conc = concentrate
IV. Flotation test~ in a modified Hallimon~ tube
ExamDles 6 to 8, Comparison Example C2
Flotation o~ 8wedi~h apatite ore
The flotation batch was a Swedish apatite ore having
the following composition, based on the principal constitu-
ents:
P2O5 : 20.1% by weight
SiO2 : 32.3% by weight
Fe2O3 : 6.3% by weight
- CaO : 34.2% by weight
The ore was present in already ground form in the
pulp. After wet screening, a particle size fraction of 50
to 100 ~m was used as the batch. The flotation cell used
was a modified Hallimond tube with a volume of 165 ml and
a stirrer speed of 400 r.p.m. Quantities of 2 g ore (dry
content) were conditioned and floated at pH 10 (adjusted
with sodium hydroxide) in water having a hardness of 20-d
(calcium ions only). The conditioning time was 5 minutes
for the hard water and 10 minutes for the collector.
Flotation was carried out over a period of 2 minutes.
The collectors according to the invention were used
either on their own or in admixture with co-collectors.
The alkyl sulfosuccinate (Bl, Comparison Example C2) was
used for comparison. The results of the flotation tests
are summarized in Table 2.
D 9130 19 ~r~
By comparison with standard collectors, Examples 6 to
8 show that the use of the esters of dicarboxylic acids
with fatty acid monoalkanolamides, either on their own or
in admixture with standard collectors, as collectors in
accordance with the invention improves both the phosphate
content of the concentrate and also the bulk recovery and
hence the phosphate recovery.
Table 2:
Flotation of Swedish apatite ore in a modified Hallimond
tube;
percentages as % by weight
Ex- Collector QU B PR PC EC SC
ample
g/t % % % %
6 A2 200 33 64 40 1.4 1.3
7 A3 (50% by weight) 200 36 71 40 1.2 1.9
B1 (50% by weight~
8 A1 (50% by weight) 100 30 57 38 1.0 1.9
B2 ~50% by weight)
C2 B1 200 27 51 38 1.7 3.8
.
Legend: QU = quantity of collector used, based on the
ore
FS = flotation stage
R = recovery
PR ~ P2O, recovery
PC 2 P2O, concentrate content
EC = Fe2O3 concentrate content
SC = SiO2 concentrate content
