RU2497960C1 - Method of separating mineral particles with pretreatment with magnetic colloid - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method involves mixing aqueous pulp of starting material with a dispersion containing colloidal magnetic particles and treating the obtained mixture in a magnetic field to extract a concentrate of the valuable component. The dispersion of magnetic particles is pre-stabilised by treatment in an aqueous medium with reagents of general formula A1-R-A2, where R is a hydrocarbon radical selected from C₃-C₁₈, A1 is COOH or CONOH, A2 is OH or CH(OH), or treatment in a liquid hydrocarbon medium with reagents of general formula A1-R, where R is a hydrocarbon radical selected from C₃-C₁₈, A1 is COOH or CONOH. After stabilisation, the dispersion is treated with a functionalising agent and mixed with the pulp of the starting material. Extraction of the concentrate of the valuable component and magnetic particles is carried out by deposition in a gravitational field in form of magnetic floccules with field strength of 80-880 KA/m or on magnetic separators in form of magnetic floccules with field strength of 32-800 KA/m.

EFFECT: high efficiency of extracting fine mineral particles using a technique for magnetisation with a magnetic colloid, followed by separation of the valuable component using magnetic techniques.

8 cl, 4 tbl, 5 ex

Description

The invention relates to the field of mineral processing and can be most effectively used in the processing of ground ores containing small amounts of a valuable mineral represented by small and fine particles, in particular gold ores.

A known method of using magnetic particles in conjunction with inorganic coagulants and organic flocculants to purify water from dissolved and suspended contaminants. The use of magnetic particles with the subsequent application of a magnetic field can significantly accelerate the deposition of floccules due to their enlargement and magnetization (O.M. Urbain, and W.R. Stemen, U.S. Patent No.2,232,294, Feb. 18, 1941).

A known method (C. de Latour, J.A.W.W.A., 68, 325, 443, 498, 1976), which consists in the use of high-gradient magnetic separation to isolate magnetite loaded with impurities, for purification of water from suspended particles, bacteria, dissolved phosphates.

The disadvantage of the above methods is that magnetite, used as a carrier in the process, does not sufficiently secure the contaminants, which, as a result of mixing with the pulp, tend to separate.

The greatest efficiency of magnetic carriers is ensured by the chemical functionalization of their surface, increasing its sorption activity and affinity for the desired types of contaminants. The greatest flexibility, with such functionalization, is provided with colloidal particle size. In this case, magnetic colloidal particles can play the role of a carrier if ions or small molecules are sorbed on them, or they can act as a magnetizing agent, which is fixed on the surface of relatively large particles, giving them magnetic properties. When using colloidal particles as carriers, increased efficiency is also provided due to the large specific surface of the magnetic colloid.

Closest to the proposed method, in combination of essential features, is a mineral separation method using magnetic methods, including dispersing the feedstock in an aqueous medium, mixing pulp with an aqueous dispersion containing colloidal magnetic particles, processing the resulting mixture in a magnetic field to extract the concentrate valuable mineral (US Patents 4, 225, 425 and 426, September 30, 1980).

The disadvantages of the closest analogue include the following: an aqueous dispersion containing magnetic particles has the property of not being sufficiently firmly attached to the surface of the mineral, as a result of which magnetic particles can be separated from the surface of the mineral when mixed.

The main objective of the invention is to increase the efficiency of extraction of fine mineral particles by using magnetization technology with a magnetic colloid, followed by the isolation of a valuable component by magnetic methods.

This is achieved by the fact that in the method of separation of mineral particles containing a valuable component comprising dispersing the feedstock in an aqueous medium, mixing the obtained pulp with a dispersion containing colloidal magnetic particles, processing the resulting mixture in a magnetic field to extract a concentrate of a valuable component, the dispersion of magnetic particles by treatment in an aqueous medium with reagents generalized formula A1-R-A2, where R is a hydrocarbon radical selected from the series C ₃ -C ₁₈ , group A1-COOH or CONOH, A2-OH or CH (OH) or treatment in a liquid hydrocarbon medium with reagents of the generalized formula A1-R, where R is a hydrocarbon radical selected from the series C ₃ -C ₁₈ , A1-COOH or CONOH, after stabilization, the dispersion is treated with a functionalizing reagent and mixed with the pulp of the feedstock containing a valuable component, and the extraction of a valuable component concentrate and magnetic particles from a mixture of mineral particles is carried out by deposition in a gravitational field, in the form of magnetic floccules with a field strength in the range of 80-880 kA / m or on magnetic separators, ide magnetic floc at a field strength in the range of 32-800 kA / m.

For processing a dispersion of magnetic particles in an aqueous medium, a functionalizing reagent is used using the generalized formula A3-R-A4, where R is a hydrocarbon radical selected from the series C ₃ -C ₁₈ , A3-COOH or CONOH, a A4-SH or OCS (SH)

To process the dispersion of magnetic particles in a liquid hydrocarbon medium, a functionalizing reagent of the generalized formula A4-R is used, where R is a hydrocarbon radical selected from the series C ₃ -C ₁₈ , group A4-SH or OCS (SH).

Processing the resulting mixture is carried out in a porous matrix, in a magnetic field, with the deposition of magnetic flocs on the media, and non-magnetic particles are removed by a stream of water.

To intensify the flocculation process, a suspension of magnetite is added to the mixture in an amount of 0.1-10% by weight of the raw material.

The magnetic field strength is selected in the range from 720-880 kA / m.

As carriers, an iron fraction of 3-6 mm is used.

As carriers use steel wool.

The essence of the proposed method lies in the fact that mineral particles (particle size 0.n-n * 10 microns) i.e. (0.1-90 microns) are mixed with magnetic colloids. As a result of mixing, colloids adhere to the surface of the mineral, which can be isolated using magnetic enrichment methods. The process of converting the surface properties of mineral particles into magnetic properties is carried out using, as a carrier, a magnetic colloid that is capable of selectively attaching itself to particles of valuable minerals. This allows you to increase the extraction of metal in concentrate and to reduce the extraction in tails.

To obtain a dispersion containing magnetite colloids, functionalizing and stabilizing reagents are used. Their choice depends on the type of ore, i.e. reagents whose groups are active in relation to a valuable mineral are selected.

The possibility of practical application of a new method for the separation of mineral particles in real ore has been tested for poor gold ore content (gold-bearing deposit of weathering crust).

Low-sulfide ore, gold content, according to assay data, 2.8 g / t. The predominant fineness of gold is less than 0.044 mm. The most common ore minerals in the sample are pyrite and arsenopyrite.

The method is as follows.

The initial gold-containing ore is ground to a content of 70-85% of a class of 0.1-0.15 mm with a ratio of T: W = 2: 1. The resulting pulp is mixed with magnetic colloids. The resulting product is separated using magnetic enrichment methods. The enrichment efficiency was evaluated by the indicators of metal extraction into the concentrate (E,%) and the metal content in the tailings (β _xv ,%). The influence of the shape of magnetite colloids on technological indicators are presented in table 1.

Example 1

The initial gold-containing ore is ground to a content of 70-85% of a class of 0.1-0.15 mm with a ratio of T: W = 2: 1. The resulting pulp is mixed with magnetite colloids previously prepared in the form of a stabilized and functionalized aqueous magnetic colloid. Magnetic colloidal particles (for example, 5-50 nm in size) are stabilized by a protein solution containing fragments of the composition A1-R-A2, where R is C ₉ , group A1 is COOH, group A2 is OH in an aqueous solution. The stabilized colloid is treated with xanthate (C ₄ H ₉ OS ₂ K) containing fragments of the composition A3-R-A4, where R is C ₄ , group A3 is COOH, and group A4 is SH containing functional groups active with respect to the valuable mineral. The results of the study are presented in table 2.

Example 2

The method is carried out as in example 1, the difference is that in this experiment the magnetite colloids are fed in the form of a magnetic colloidal solution emulsified in water in apolar liquids. A stabilized colloidal solution of magnetite in kerosene is emulsified in water with the addition of xanthate (C ₄ H ₉ OS ₂ K) containing fragments of the composition A4 - R, where R is C ₄ and the A4 group is SH, and a stabilizing reagent, which is convenient to use as aliphatic alcohols (C ₄ H ₉ OH) containing fragments of composition A2-R, where R is C4, group A2-OH, everything is mixed, the emulsion is formed by the usual shaking of the mixture. Isolation of a valuable component is carried out by magnetic enrichment methods. The results of the study are presented in table 3.

Example 3

The initial gold ore with a content of 70-85% of a class of 0.01 mm mixed with magnetite colloids previously prepared in the form of a stabilized and functionalized aqueous magnetic colloid or in the form of a magnetic colloidal solution emulsified in water in apolar liquids. The separation of a valuable component is carried out on high-gradient separators. Steel wool is used as a carrier of magnetic particles. The results of the study are presented in table 2, 3.

Example 4

The method is carried out as in example 1, the difference is that the separation of the valuable component is carried out by magnetic flocculation, and to intensify the process, a suspension of Fe ₃ O ₄ is added in an amount of 0.1-10% by weight of the raw material. The separation of magnetic flocculi is carried out by deposition in a gravitational field with a field strength in the range of 80-880 kA / m or on separators in the form of magnetic floccules with a field strength in the range of 32-800 kA / m, Tables 2, 3.

The results of the study are presented in table 5.

Example 5

The method is carried out as in example 2, the difference is that in this experiment, Cu is used as a valuable valuable component. The initial ore is ground to a content of 70-85% of a class of 0.1-0.15 mm with a ratio of T: W = 2: 1. The resulting pulp is mixed with magnetite colloids previously prepared in the form of a magnetic colloidal solution emulsified in water in apolar liquids. A stabilized colloidal solution of magnetite in kerosene is emulsified in water with the addition of xanthate (C ₄ H ₉ OS ₂ K) containing fragments of the composition A4 - R, where R is C ₄ and the A4 group is SH, and a stabilizing reagent, which is convenient to use oleic acid (C ₁₇ H ₃₃ COOH) containing fragments of composition A2-R, where R is C ₁₇ , group A2-COOH, everything is mixed, the emulsion is formed by the usual shaking of the mixture. Isolation of a valuable component is carried out by magnetic enrichment methods. The results of the study are presented in table 4.

The proposed method will reduce the loss of gold in the processing of ores and involve finely disseminated ores, weathering crust ores, ores with refractory gold, and technogenic formations in the production.

Instead of the reagents used, any of their analogues can be used, the use of which, given the current state of the art and technology, reduces the cost of enrichment.

Table 1 The influence of the shape of magnetite colloids on technological indicators Options Values E% β _hv ,% Form of colloids Fe ₃ O ₄ In the form of a stabilized and functionalized aqueous magnetic colloid; 83.81 0.75 In the form of a magnetic colloidal solution emulsified in water in apolar liquids. 80,10 0.98

table 2 The influence of methods for extracting a valuable component when feeding particles in the form of a stabilized and functionalized aqueous magnetic colloid on technological indicators Options Values E% β _xn ,% Precipitation in a gravitational field 69.96 0.93 On a magnetic separator with a strength of 320 kA / m 74.04 0.85 On high gradient separators 84.49 0.73 On high gradient separators: - Magnetic field strength, kA / m 720 78.54 0.86 800 81.63 0.80 880 83.73 0.76 - Carrier Fraction 3 mm 85.84 0.69 Fraction 6 mm 84.39 0.73 Steel wool grade 00 86.90 0.61 Steel wool grade 0 86.27 0.63

Table 3 The influence of methods for the extraction of a valuable component when feeding particles in the form of a magnetic colloidal solution emulsified in water in apolar liquids on technological parameters Options Values E% β _hv ,% Precipitation in a gravitational field 69,20 0.95 On a magnetic separator with a strength of 120 kA / m 72.85 0.88 On high gradient separators 100.00 0.00 On high gradient separators: - Magnetic field strength, kA / m 440 75.65 0.95 640 80.58 0.84 880 83.73 0.76 - Carrier Fraction 3 mm 85.05 0.71 Fraction 6 mm 83.73 0.76 Steel wool grade 00 86.53 0.64 Steel wool grade 0 85.39 0.68

Table 4 The influence of methods for extracting a valuable component when feeding particles in the form of an emulsified magnetic water colloidal solution in apolar liquids on technological parameters Options Values E% β _hv ,% Precipitation in a gravitational field 47.55 3,1 On a magnetic separator with a strength of 120 Ka / m 60.94 2,5 On high gradient separators in a porous matrix 71.59 1.8 On highly gradient separators in a porous matrix: - Magnetic field strength, kA / m 440 65.21 2.2 640 68.61 2 880 70.10 1.9 - Carrier Fraction 3 mm 67.98 2 Fraction 6 mm 63.3 2,3 Steel wool grade 00 71.69 1.7 Steel wool grade 0 74.50 1.65

Table 5 The effect of magnetite suspension on technological indicators Options Values E% βhv,% A suspension of magnetite,% by weight of raw materials 0.1 77.86 0.69 3 86.02 0.45 10 91.56 0.28

Claims (8)

1. The method of separation of mineral particles containing a valuable component, including dispersing the feedstock in an aqueous medium, mixing the resulting pulp with a dispersion containing colloidal magnetic particles, processing the resulting mixture in a magnetic field to extract a concentrate of a valuable component, characterized in that the dispersion is stabilized beforehand magnetic particles by treatment in an aqueous medium with reagents with the generalized formula A1-R-A2, where R is a hydrocarbon radical selected from the series C ₃ -C ₁₈ , group A1 is COOH or CONOH, A2 is O H or CH (OH), or by treating in a liquid hydrocarbon medium with reagents the generalized formula A1-R, where R is a hydrocarbon radical selected from the series C ₃ -C ₁₈ , group A1 is COOH or CONOH, after stabilization the dispersion is treated with a functionalizing reagent and mixed with a pulp of feedstock containing a valuable component, and the extraction of a valuable component concentrate and magnetic particles from a mixture of mineral particles is carried out by deposition in a gravitational field in the form of magnetic flocs at a field strength in the range of 80-880 kA / m or on magnetic separators tori in the form of magnetic flocs with a field strength in the range of 32-800 KA / m. 2. The method according to claim 1, characterized in that for processing the dispersion of magnetic particles in an aqueous medium, a functionalizing reagent is used using the generalized formula A3-R-A4, where R is a hydrocarbon radical selected from the series C ₃ -C ₁₈ , group A3 is selected from the group COOH or CONOH, and group A4 from the group SH or OCS (SH). 3. The method according to claim 1, characterized in that for processing the dispersion of magnetic particles in a liquid hydrocarbon medium, a functionalizing reagent of the generalized formula A4-R is used, where R is a hydrocarbon radical selected from the series C ₃ -C ₁₈ and the group A4 is selected from SH or OCS (SH). 4. The method according to claim 1, characterized in that the processing of the resulting mixture is carried out in a porous matrix in a magnetic field with the deposition of magnetic flocs on the media, and non-magnetic particles are removed by a stream of water. 5. The method according to claim 1 or 4, characterized in that in order to intensify the flocculation process, a suspension of magnetite is added to the mixture in an amount of 0.1-10% by weight of the raw material. 6. The method according to claim 1 or 4, characterized in that the magnetic field is selected in the range from 720-880 kA / m 7. The method according to claim 4, characterized in that as carriers use an iron fraction of 3-6 mm 8. The method according to claim 4, characterized in that steel wool is used as the carrier.