Note: Descriptions are shown in the official language in which they were submitted.
CA 02483165 2004-10-20
2002DE417
WO 03/089144 PCT/EP03/03592
Description
Use of fatty amine salts in combination with fatty acids as reagents for the
flotation of potash salts (sylvinite)
The present invention relates to the use of amine salts in combination with
fatty acids as flotation reagents in the production of sylvinite, and also to
a
15
corresponding reagent.
In the production of sylvinite from crude potash salts which occur, for
example, in Germany, Belarus, CIS, Canada and the United States of
America, it is necessary in some cases to remove foreign minerals, such as
clays, dolomite, anhydride, hematite and other materials, preferably
upstream of the flotation separation of sylvinite, from other crude potash
salt components. The removal of foreign materials which are customarily
termed slimes or insoluble fractions, is carried out by flotation. In
flotation
processes a crude salt pulp is customarily first subjected to a scrubbing
operation to release the insoluble fractions, which are termed hereinafter
insoluble fractions, and the cleaned crude salt pulp is then conditioned
using one or more reagents which promote the removal of the insoluble
fractions. The conditioned pulp is subjected to a froth separation, which
removes a part of the insoluble constituents. Flocculants can be used to
improve the separation. After the partial removal of the insoluble fractions,
customarily an additive (blinding agent) is added to the crude salt pulp to
inactivate residues of the insoluble fractions, conditioned with reagents and
subjected to the froth separation for production of sylvinite and other crude
potash salt components.
Because of numerous advantages, the flotation process for separating
potash salt mixtures of natural or industrial origin to form intermediates or
potash fertilizers by means of fatty amine collectors is widespread. By
adding the fatty amine or salts thereof to the flotation pulp, the mineral
component of value becomes hydrophobic and thus capable of being
discharged in enriched form in the concentrate and isolated. Obviously, the
chemical constitution of the collector, its preparation and the conditions of
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2
its metering have the greatest effect on its adsorption and thus on its
action. Generally, primary fatty amines are used. In mixtures with these
amines, short-chain alkylamines are used, for example as are present in
cocoamine.
DD-B-154 960 discloses a fatty amine for the flotation of potash salts which
has virtually saturated alkylamines produced from natural or synthetic
starting substances in a ratio of the chain length fragments of
C16~C18~C20=C22 such as from 10 to 25: from 55 to 70: from 4 to 10: from
5 to 20, preferably 15:65:5:10, and has a content of at least 92% primary
amines.
US-4 045 335 discloses a process for the flotation of langbeinite and
kieserite in which a reagent is used which, in addition to a fatty amine,
preferably tallow fatty amine, also contains oleic acid or decanedioic acid.
It was an object of the present invention to provide a flotation reagent which
enhances the KCI recovery in sylvinite flotation without decreasing the
concentrate quality.
Surprisingly, it has been found that a mixture of a primary alkylamine salt
and a branched fatty acid significantly enhances the flotation recovery
compared with conventional collectors. The KCI content of the resultant
concentrate produced is not decreased by the higher activity of the novel
collector.
The invention thus relates to the use of a mixture of
A) at least one compound of the formula
[R~-NH3]+X
where R~ is a Cg-C22 alkyl radical and X is an anion, and
B) a branched fatty acid having a chain length of 8 to 22 carbon atoms
as collector in sylvinite flotation.
The invention further relates to a process for the flotation of sylvinite, in
which the abovedescribed composition is added as collector to the flotation
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3
pulp.
The invention further relates to a composition effective as flotation reagent
comprising
A) at least one compound of the formula
[R~-NH3]+X
where R~ is a Cg-C22 alkyl radical and X is an anion, and
B) a branched fatty acid having a chain length of 8 to 22 carbon atoms.
Substituent A of the inventive composition preferably comprises a radical
R~ having a chain length of 12 to 20, in particular 16 to 20, especially 18,
carbon atoms. X can be any desired anion, but is preferably a chloride,
formate, or acetate anion. A particularly preferred substituent A is
stearylamine acetate.
Constituent B of the inventive composition is preferably a branched
carboxylic acid having 14 to 22 carbon atoms, in particular isostearic acid.
The preferred mixing ratio of A:B is 90:10 to 10:90, in particular 75:25 to
25:75. In a further embodiment, the constituents A and B total 100% by
weight.
For simplified handling of the inventive composition, this can be formulated
with solvents. Suitable solvents are glycols, in particular butyl polygiycol,
the residues from oxoalcohol synthesis, and also if appropriate water as
minor constituent.
Residues from oxoalcohol synthesis preferably have the following
composition:
Concentration range
Constituent (% by weight)
Di-2-ethylhexyl ether 10-25
2-Ethylhexanoic acid 2-ethylhexyl 10-25
ester
Cog lactones 4-20
2-Ethylhexyl butyrate 3-10
2-Ethylhexane-(1,3)-diol mono-n-butyrate5-15
CA 02483165 2004-10-20
2-Ethythexano) 4-9 0
C4 to Cg acetals 2-10
2-Ethylhexane-( 1,3)-diol 2-5
Ethers and esters ~ C2p 0-20
In a further embodiment of the invention the inventive compositions are
used in a mixture with quaternary ammonium salts. Such salts have the
formula [NRZR3R4R5J~X~, where R2, R3, R4 and R5 are alkyl radicals
having 1 to 18 carbon atoms. Preferably, one of the radicals R~ to R5 is a
short-chain radical, for example methyl or ethyl, and the other radicals are
tong-chain radicals having 8 to 1 B carbon atoms, Two short-chain radicals
can also be combined with 2 long-chain radicals. Suitable anions X are
chloride and sulfate.
In a further embodiment of the invention the inventive compositions are
used in a mixture with ether propyleneamines. of the fvrrnula
RB-O-(CH2)g-NHS andlor ether propylenediamines of the formula
Rg-O-(CH2)3-NH-(CN2)3-NH2. Rg here is an alkyl group having 8 to
18 carbon atoms. It is also possible to use the ether propylene(di)amlnes In
the farm of their salts, in particular chlorides, acetates or farmates.
The inventive composition is used as a flotation reagent in amounts of
preferably 14 to 500, in particular 20 to 200 g/t.
Examples
Hereinafter, the effectiveness of the inventive flotation reagent was
determined. Gonstttuent A was stearylamine acetate, constituent E was
tsostearic acid. The amount used was 40 gIt (t.q,). The mixing ratio A:B
was 1:1.
The crude salt was ground and suspended in a saturated salt solution.
After addition of the collector, air was forced through the suspension. The
salt which was rendered hydrophobic by the collector floats as a result on
the surtace of the suspension and is skimmed off there. The potassium
80 content o~F the concentrate thus obtained was determined, and also its
ratio
to the total amount of potassium present (recovery).
The following results were obtained:
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Table 1
No. Collector K20 in the K20 K~O
concentrate recove feed
1 Stea lamine 48.2 77.1 9.78
C
2 Stearylamine acetate + 47.2 61.7 9.78
(C)
(Cg)3C-COOH
3 Stearylamine acetate + 49.1 72.8 9.78
(C) lauric
acid
4 Stearylamine acetate + 50.8 82.0 9.78
isostearic acid
5 Stearylamine acetate + 50.1 48.6 9.78
(C) stearic
acid
