RU2741494C1 - Method of treating siliceous non-sulphide ores and corresponding composition of collectors - Google Patents

Abstract

FIELD: chemistry.SUBSTANCE: invention relates to a method of treating siliceous non-sulphide ores, said method comprising adding a collector composition which contains a phosphate compound of formula I, in which R denotes a linear or branched, saturated or unsaturated hydrocarbon group containing 8 to 24 carbon atoms, A is an alkylene oxide link, Y is H, Na, K, ammonium or alkylated ammonium, n = 1–3, p = 0–25, X is selected from the same groups as RApor Y, or where R denotes a linear or branched, saturated or unsaturated hydrocarbon group containing 1–12 carbon atoms, and there is at least one link A, which is a propylene oxide link. Invention also relates to composition and pulp.EFFECT: use of the proposed invention ensures required degree of extraction of the desired product from ore and improved extraction and selectivity.10 cl, 3 ex, 2 tbl, 1 dwg

Description

The present invention relates to a method for treating siliceous non-sulphide ores, such as siliceous phosphate ores, and collector compositions suitable for use in such methods.

Froth flotation is a physicochemical method used to separate mineral particles considered economically valuable from waste. It is based on the ability of air bubbles to attach to particles that have previously been rendered hydrophobic. Combinations of particles with bubbles then rise into the froth phase where they are discharged from the flotation cell, while the hydrophilic particles remain in the flotation cell. The hydrophobicity of the particles, in turn, is caused by special chemicals called collectors. In direct flotation systems, it is the economically valuable materials that are rendered hydrophobic by the action of the collector. Likewise, in reverse flotation systems, the collector makes the mineral particles, which are considered waste, hydrophobic. The efficiency of the separation process is quantified by recovery and enrichment. Recovery refers to the fraction of the valuable product contained in the ore that has been removed to the concentrate stream after flotation. The beneficiation ratio refers to the percentage of an economically valuable product in the concentrate after flotation. Higher recovery or concentration indicates a more profitable flotation system. Typically, for a collector to be of economic interest in its application, it is necessary to achieve some minimum degree of enrichment, and for this minimum degree of enrichment, the highest recovery possible. In collector compositions, typically for improving recovery, efficiency, foaming characteristics, etc. is primarily responsible for the secondary collector, and the primary collector is responsible for selectivity.

DE 4016792 as well as DE 4010279 and DE 4133063 describe a method for treating siliceous non-sulfide ores by a flotation method. DE '792 uses mixtures of dicarboxylic acid esters with fatty acid monoalkylamides as collector compositions, optionally in combination with additional anionic or nonionic surfactants. DE '279 uses dicarboxylic acid N-alkyl monoamides as collector compositions, optionally in combination with additional anionic or nonionic surfactants. DE '063 uses ether amines as collector compositions with at least one additional anionic or non-ionic collecting component. Alkyl phosphates and alkyl ether phosphates of formulas XVII and XVIII of DE '792 represent one possible variant (of many) compounds that can be used as such (optional or secondary) collection component. The use of phosphate compounds as a primary collector is not described or suggested in any of these documents. Likewise, none of the examples demonstrate the use of a pyrophosphate component in a collector composition, nor does it disclose or suggest that alkylated di- or higher phosphates are beneficial in the flotation process.

EP 544185 describes a method for treating non-sulfide siliceous ores using a collector composition that contains a sulfosuccinate as a primary collector and, optionally, an additional surfactant, which can be selected from a wide range of possibilities and which also contains an alkyl phosphate or an alkyl ether phosphate. The use of phosphate compounds as primary collector is not described or suggested in EP 544185. Moreover, EP 544185 does not disclose alkyldiphosphate, alkyltriphosphate or alkyltetraphosphate compounds. None of the examples of EP 544185 show the use of phosphate in the composition of collectors and do not consider the difference between different phosphate compounds.

GB 1093504 describes a process for treating siliceous ore using a phosphorus atom-containing compound of the formula R _a H _b P _c O _d , where c can be 1 or 2. The phosphate compounds can be alkylated and are preferably hypophosphates. Pyrophosphates are also proposed but have not actually been tested. The ore processing method aims to separate some valuable minerals from the ore. The flotation process according to GB '504, where the valuable mineral is phosphate (example 11), is a flotation process at preferably low pH, wherein the phosphate is collected in foam. The phosphate compound in this example is a lauryl alcohol-based hypophosphate and the results of the flotation process, with a P ₂ O ₅ sample of 28%, are poor.

The present invention provides a method for treating siliceous non-sulfide ores with a collector composition that includes a phosphate compound of Formula I

in which R denotes a linear or branched, saturated or unsaturated hydrocarbon group containing from 1 to 24 carbon atoms, A denotes an alkylene oxide unit, Y denotes H, Na, K, ammonium or alkylated ammonium, n = 1-3, p = 0- 25, X is selected from the same groups as RA _p or Y.

In this document, compounds of formula I in which n is from 1 to 3 are sometimes also referred to as "pyrophosphates" in order to distinguish them from "monophosphates" in which n is 0.

In addition, the invention relates to a collector composition for a method for treating siliceous non-sulfide ores, the collector composition comprising the aforementioned phosphate compound of formula I as a primary collector and a secondary collector comprising a monophosphate compound and one or more other secondary collecting compounds, which may be anionic a collecting compound selected from the group of fatty acids, alkyl sulphosuccinates, alkyl maleates, alkyl amidocarboxylates, esters of alkyl amidocarboxylates, alkyl benzene sulphonates, alkyl sulphonates, fatty sulphonic acids, or a non-ionic collecting compound from the group of ethoxylates, glycosides, ethanol or more ionic collectors of these anions, or a mixture of these anionic collectors, ethanol or more.

The present invention provides an improved process for treating siliceous ores and collector compositions for use in the process that provide the desired recovery of the desired product from the ore and improved recovery and selectivity. In addition, the present invention provides an improvement in that a lower total amount of collector composition can be used in the flotation process.

It should be noted that US Pat. No. 4,287,053 describes a phosphate depressant for treating siliceous phosphate ores. However, it is known that the function of depressants differs markedly from that of collectors. In addition, in US 2424552 phosphates are described as a depressant, which in this document are all inorganic phosphates. In the examples, hexametaphosphate is used. This document does not describe organic phosphates such as phosphates containing a hydrocarbon group.

When R is a group having 1 to 12 carbon atoms, the branching degree DB is preferably 0 to 2.2, and p is greater than zero. When R contains from 1 to 12 carbon atoms, preferably at least one A unit is present which is a propylene oxide unit. Even more preferably, when R contains from 1 to 10 carbon atoms, p is from 1 to 25, even more preferably from 4 to 10, and most preferably from 5 to 8. When R contains from 1 to 10 carbon atoms, even more preferably one or multiple A units are propylene oxide or butylene oxide, or when R contains 1 to 10 carbon atoms, in another more preferred embodiment, the propylene oxide unit A unit is first bonded to R and then to the ethylene oxide unit A unit.

When R is a group containing from 12 to 16 carbon atoms, p is preferably greater than 0, and in a further preferred embodiment of the group A is propylene oxide, ethylene oxide or a combination of propylene oxide and ethylene oxide. When the R group contains 12-16 carbon atoms, it is preferably branched. Even more preferably, the degree of branching is 0.2 to 3.

When the R group contains more than 16 carbon atoms, it is preferably linear and unsaturated. More preferably, when p is greater than 0 and R contains more than 16 carbon atoms, one or more of the A groups is ethylene oxide. Even more preferably, when R contains more than 16 carbon atoms, the degree of unsaturation is 0.2-2, most preferably 0.5-1.1.

If the degree of alkoxylation (DA, p value) is 0, then R is preferably a group containing from 8 to 16 carbon atoms, even more preferably R is a group containing from 9 to 15 carbon atoms. In another preferred embodiment, R is a saturated hydrocarbon group. When the R group contains up to 12 carbon atoms inclusive, it is preferably linear or branched to a limited extent. When R contains more than 12 carbon atoms, it is preferably branched. Even more preferably, when R contains up to 12 carbon atoms, inclusive, the degree of branching is 0-2.2, and when R contains more than 12 carbon atoms, the degree of branching is preferably from 1.5 to 3.

In another preferred embodiment, each A is independently a propylene oxide group or an ethylene oxide group. Even more preferably, A is an ethylene oxide group. The p value is preferably 0-15, more preferably 1-10, most preferably 2-8. If R contains more than 12 carbon atoms, the value of p is preferably selected higher than when R contains up to 12 carbon atoms, inclusive.

By the degree of alkoxylation (DA), as used herein, is meant the total number of alkylene oxide units A between the alkyl chain R and the phosphorus-containing unit, which corresponds to the value of p in formula I. As understood by a person skilled in the art, the degree of alkoxylation is an average value and not necessarily must be an integer. Suitable alkylene oxide units A are ethylene oxide, propylene oxide or butylene oxide.

By "degree of unsaturation" (DU), as used herein, is meant the total number of double bonds in the alkyl chain. It should be noted that the degree of unsaturation is the average of the R groups present in the phosphate compound of Formula I or Formula II, and therefore does not have to be an integer.

By "degree of branching" (DB) as used herein is meant the total number of (terminal) methyl groups present in the alkyl chain R minus one (side chains other than methyl alkyls are counted by their terminal methyls). It should be noted that the degree of branching is the average of the R groups present in the phosphate compound of Formula I, and therefore does not have to be an integer.

In another preferred embodiment, n = 1.

In one embodiment, the method of the invention relates to the recovery of apatite from non-sulfide siliceous ores.

Siliceous ores are ores that contain silicon oxide (SiO ₂ ). In preferred embodiments, siliceous ores contain 5 to 80 wt% silica. Even more preferably, siliceous ores contain from 20 to 75 wt.% Silicon oxide.

The amount of phosphate minerals such as apatite in the siliceous ore in embodiments is from 8 to 40 wt%, preferably 10 to 30 wt%. In other embodiments, the ores may contain other basic minerals such as iron oxide minerals, which will be defined in more detail below.

In one embodiment, the method is a method for selective flotation of apatite.

In a preferred embodiment, the method is a direct flotation method, even more preferably a direct flotation method for recovering phosphate minerals from siliceous ores.

In the process according to the present invention, the pH is preferably 8 to 11.

A collector composition according to the present invention for use in a method for treating non-sulfide siliceous ores comprises a primary collector which contains a phosphate of the above formula (I) in which R, X, Y, A, p and n have the same meanings as above, monophosphate secondary collecting compound, which preferably corresponds to formula II

and one or more other secondary collectors, which may be

an anionic collector selected from the group of fatty acids, preferably having the formula RCOOY, fatty sulfonic acids, preferably having the formula RCH (SO ₃ Y) COOY, alkyl sulfosuccinates, preferably having the formula III

alkyl maleates, preferably having the formula IV

alkylamidocarboxylates, preferably having the formula V

moreover, in all structures and formulas II-V above, each R, A, p, Y independently have the meaning defined above for formula I, m = 0-7, B means -H, -CH ₃ , -CH (CH ₃ ) ₂ , -CH ₂ CH (CH ₃ ) ₂ , -CH (CH ₃ ) CH ₂ CH ₃ , Z means -H, -CH ₃ or -CH ₂ CH ₃ , esters of the above alkylamidocarboxylates (alkylamidocarboxylate compounds of formula V, in which Y is a hydrocarbon group derived from alcohol as also described in US 2016/0129456),

alkylbenzenesulfonates, preferably having the formula VI

alkyl sulfonates, preferably of formula VII

- or a non-ionic collector from the group of alkoxylates (alkoxylated fatty alcohols RO (A) H, alkoxylated fatty acids RC (O) O (A) H), alkyl glycosides R (C ₆ O ₆ H ₁₁ ) _k , alkyl ethanolamides of formulas VIII or IX

where each R, A and Z independently has the meaning indicated above, f = 1-25, preferably f = 1-15 and most preferably f = 1-10, k = 1-5, preferably k = 1-2, and each f independently means from 1 to 25;

- or a mixture of two or more of these anionic and nonionic collectors.

The monophosphate secondary collecting compound can be added to the collector composition intentionally and separately and can be selected from the group of compounds defined above in relation to Formula II, but the monophosphate compound can be formed by itself during the preparation of the primary phosphate collecting compound of Formula I above. If such other phosphates are not removed from the composition obtained in the preparation of the phosphate compound of Formula I, a composition is obtained which inherently contains both the primary collector of the present invention and a monophosphate secondary collector.

Preferably, the primary collector is present in an amount of 5-60 wt.%, More preferably 10-60 wt.%, A monophosphate secondary collector in an amount of 5-75 wt.%, More preferably 10-75 wt.%, And any other secondary collector in an amount of 1-50 wt.%, with the weight percent calculated on the weight of all solids present in the collector composition.

In preferred embodiments, the amount of monophosphate secondary collector is 25 to 75 wt%, more preferably 30 to 65 wt%, based on the total solids content of the collector composition, since monophosphates, as explained above, are often formed in di- , tri- and tetraphosphates, and for the purposes of using higher phosphates in the collector composition, it is not necessary to remove monophosphates, since they can play the role of a secondary collector. Other secondary collectors are preferably present in an amount of 5-50 wt%. The amount of the phosphate compound of formula I in the collector compositions and method of the present invention is preferably 5 to 50% by weight.

In another preferred embodiment, the amount of phosphate compound of Formula I in the collector compositions and method of the present invention is 5 to 45 wt%, even more preferably 10 to 40 wt%, and most preferably 15 to 35 wt% of the total phosphate ... The collector composition can be added to flotation in concentrated form (i.e. 5-100 wt% solids, preferably 50-100 wt% solids) or as an aqueous solution of 1-5 wt% concentration.

The method and composition of collectors according to the invention may include other additives and auxiliary materials that are typically present in the froth flotation process and which can be added simultaneously or, preferably, separately during the process. Additional additives that may be present during the flotation process are depressants (such as starch, dextrin, quebracho), dispersants (such as water glass), foaming agents / foam regulators / foam modifiers / defoamers (such as MIBC, Texanol, alkoxylated low molecular weight alcohols ) and pH regulators (such as NaOH).

In another aspect, the present invention relates to a slurry containing crushed and ground ore, a primary collector or collector composition as defined herein, and optionally other flotation aids. This slurry can be prepared by first grinding the ore and then adding the collector composition, or by adding at least a portion of the collector composition to the ore and grinding the ore to form a slurry in the presence of at least a portion of the collector composition.

Siliceous ores that can be used in the process according to the invention may include additional minerals in addition to silicon oxides and phosphates. The mineral composition of most siliceous ore deposits around the world is usually similar, differing only in the percentage of each mineral present, depending on their origin. Other minerals present in siliceous ores can be gneisses, granites, and pegmatites, including ilmenite, rutile, monazite, zircon, sillimanite, kyanite, andalusite, garnet, spinel, corundum, staurolite, tourmaline and epidote.

The amount of collector used in the reverse flotation process of the present invention will depend on the amount of impurities present in the ore and on the desired separation effect, but in some embodiments it will be in the range of 10-1000 g / t dry ore, preferably in the range 20-500 g / t dry ore, more preferably 25-200 g / t dry ore.

Below the present invention is illustrated by examples.

Example 1A

Synthesis of alkyl ethoxylated pyrophosphate

To a flanged glass reactor equipped with an overhead stirrer was added oleyl alcohol (60.0 g) ethoxylated with 4 equivalents of EO. The reactor was purged with nitrogen for 10 minutes. The mixture was heated in an oil bath to 55 ° C and methylsulfonic acid (3.69 g) was added. Phosphorus pentoxide (9.71 g) was added in portions while maintaining the temperature at 55 ° C. Stirring at 55 ° C under nitrogen atmosphere was continued overnight. The final product was analyzed by ³¹ P-NMR spectroscopy. ³¹ P-NMR (CDCl ₃ ): δ 4 to -1 ppm alkylated monophosphate; δ -12 to -16 ppm alkylated pyrophosphate; δ from -28 to -30 ppm inorganic phosphates.

Example 1B

Synthesis of alkylated pyrophosphate

Isotridecanol (40 g, 200 mmol) was added to a flanged glass reactor equipped with an overhead stirrer. The reactor was purged with nitrogen for 15 minutes. The mixture was heated in an oil bath to 55 ° C and methylsulfonic acid (5.39 g, 5.39 mmol) was added. Phosphorus pentoxide (14.2 g, 100.0 mmol) was added in portions while maintaining the temperature at 55 ° C. Stirring at 55 ° C under nitrogen atmosphere was continued overnight. The final product was analyzed by ³¹ P-NMR spectroscopy. ³¹ P-NMR (CDCl ₃ ): δ 4 to -1 ppm monophosphate; δ from -12 to -16 ppm pyrophosphate; δ from -28 to -30 ppm polyphosphate.

Example 2

General flotation procedure

Five hundred (500) grams of a phosphate ore containing 25% apatite and 70% various siliceous minerals were placed in a 1.4 L Denver flotation cell, water was added to the marked level, and mixing was started. Then 1 minute was conditioned with 10.0 ml of an aqueous solution of starch 1% (w / w), keeping the pH of the flotation mixture at 9.9 with a 5% aqueous solution of NaOH. The collector was then added as a 1% (w / w) solution and conditioning was continued for 2 minutes while maintaining the pH of the flotation mixture at 9.9 with 5% aqueous NaOH. Flotation was carried out at room temperature (20 ± 1 ° C) and air supply at a rate of 3.5 L / min. Coarse flotation was carried out followed by two stages of purification (Denver chamber 1.0 L). All fractions (tailings, middlings and concentrate) were collected and analyzed. Figure 1 illustrates the flotation steps performed and the various collected fractions.

We compared the following two compositions of the collectors:

- collector composition 1 (according to the invention): 67 wt.% fatty oleic acid, 23 wt.% oleylethoxylate monophosphate (4EO), 10 wt.% oleyl alcohol ethoxylate pyrophosphate (4EO) obtained in example 1A,

- collector composition 2 (comparative): 67 wt.% fatty oleic acid, 33 wt.% oleylethoxylate monophosphate (4EO), obtained by the reaction of ethoxylated oleyl alcohol used in example 1A, with polyphosphoric acid.

The number of cleaning stages depends on how much solid material is contained in the foam products. The flotation continues until there are no more particles left in the foam. The time above indicates how long it will take.

The collectors shown in Table 1 were used in the flotation process above, and the results of flotation with these collectors are shown in Table 1. The selectivity was calculated according to the following equation:

,

,

Where

The selectivity factor should be as high as possible.

Table 1. Flotation Results Representing P ₂ O ₅ Recovery and Enrichment

Phosphate collector component Dosage
g / t Fraction Amount of phosphate per P ₂ O ₅ Selectivity factor enrichment% recovery% Collector 1 of fig.
(oleyl alcohol + 4EO mixture of mono- and pyrophosphate) 130 rough concentrate 29.49 96.6 1.8 1st pure concentrate 36.56 94.6 0.7 2nd pure concentrate 39,00 91.8 0.3 Comp. collector 2
(oleyl alcohol + 4EO monophosphate only) 150 rough concentrate 28.78 96.4 2.0 1st pure concentrate 36.67 93.5 0.6 2nd pure concentrate 39.50 87.8 0.2

From the results presented in Table 1, it can be seen that the use of alkoxylated alkyl pyrophosphate makes it possible to obtain a high-quality apatite concentrate (enrichment = 39%) with a recovery above 90%, using about 12% less total collector mixture, while using only monophosphate gives less good results.

Example 3

Example 2 was repeated, but the following two collector compositions were compared (for dosages, see table 2 below):

- collector composition 3 (according to the invention): 60 wt.% isotridecyl pyrophosphate (n = 1-3) and 40 wt.% isotridecyl monophosphate (n = 0) obtained in example 1B;

- collector composition 4 (comparative): 100% isotridecyl monophosphate (n = 0), obtained by the reaction of isotridecanol with polyphosphoric acid.

The results are summarized in Table 2 below.

Table 2. Flotation Results Representing P ₂ O ₅ Recovery and Enrichment

Collector Dosage, g / t Fraction Amount of phosphate per P ₂ O ₅ enrichment% recovery% Collector 3 per fig.
(mixture of 60% isotridecyl pyrophosphate
+ 40% isotridecyl monophosphate) 100 rough concentrate 32.07 91.8 1st pure concentrate 38.33 86.1 2nd pure concentrate 39.69 80.3 Comp. collector 4
(100% isotridecyl monophosphate) 100 rough concentrate 25.83 35.1 1st pure concentrate 35,15 23.2 2nd pure concentrate 38.25 18.4

This example demonstrates that the use of monophosphate alone results in very poor collecting properties in siliceous ores.

Claims (17)

1. A method of treating siliceous non-sulfide ores, said method includes adding a collector composition that contains a phosphate compound of formula I

in which R means a linear or branched, saturated or unsaturated hydrocarbon group containing from 8 to 24 carbon atoms, A means an alkylene oxide unit, Y means H, Na, K, ammonium or alkylated ammonium, n = 1-3, p = 0- 25, X is selected from the same groups as RA _p or Y, or in which R is a linear or branched, saturated or unsaturated hydrocarbon group containing from 1 to 12 carbon atoms and at least one unit A is present, which is propylene oxide link. 2. A process according to claim 1, wherein R is a group containing from 9 to 20 carbon atoms. 3. A method according to any one of claims. 1 or 2, with n = 1. 4. A method according to any one of claims. 1-3, with p = 1-8. 5. The method according to any one of claims. 1-4, the method being a method for separating phosphates from ores. 6. The method of claim 5, wherein the method is a direct flotation method for separating apatite from ores. 7. A method according to any one of claims. 1-6, and the pH during the process is from 8 to 11. 8. Composition collectors for use in the method according to any one of paragraphs. 1-7 containing - primary collector, which contains a phosphate compound of formula I

in which R means a linear or branched, saturated or unsaturated hydrocarbon group containing from 8 to 24 carbon atoms, A means an alkylene oxide unit, Y means H, Na, K, ammonium or alkylated ammonium, n = 1-3, p = 0- 25, X is selected from the same groups as RA _p or Y, or in which R is a linear or branched, saturated or unsaturated hydrocarbon group containing from 1 to 12 carbon atoms and at least one unit A is present, which is propylene oxide link, - secondary collector, which is monophosphate, - one or more other secondary collectors, which is an anionic collector selected from the group of fatty acids, alkylsulfosuccinates, alkylmaleates, alkylamidocarboxylates, esters of alkylamidocarboxylates, alkylbenzenesulfonates, alkylsulfonates, fatty sulfonic acids, or contains nonionic collectors from the group of alkylatels, alkyl ethanol a mixture of two or more of these anionic and nonionic collectors. 9. Composition collectors according to claim 8, where the amount of phosphate compounds of formula I is from 5 to 45% by weight. based on the total amount of phosphate in the composition of the collectors. 10. A slurry for use in a flotation process containing crushed and ground siliceous ore and a collector composition according to claim 8 or 9.

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