RU2398903C1 - Procedure for processing persistent uranium containing pyrite and valuable metals of materials for extraction of uranium and production of concentrate of valuable metals - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: procedure consists in sulphuric acid leaching of uranium. Also source material of 0.1-0.3 mm dimension is subjected to sulphuric acid leaching in autoclave till over 95% of uranium is transited to solution and till degree of pyrite oxidation reaches not less, than 50%. Upon separation of uranium containing solution from a solid phase in form of a cake the latter is conditioned by flotation of valuable metals with sulphydric collector and oxy-ethylated compound at pH 2.5-7.0 thus producing concentrate of valuable metals.

EFFECT: high degree of decomposition of persistent minerals of uranium and pyrite oxidation associating silver and gold and efficient extraction of uranium into water phase and valuable metals into floated concentrate.

17 cl, 1 dwg, 7 tbl, 5 ex

Description

The invention relates to the field of hydrometallurgy and enrichment of uranium and precious metals, in particular to the processing of refractory refractory resistant uranium gold-bearing materials from the Elkon plateau deposit of the Elkon uranium ore region.

The main concentrator of uranium (80%) in these ores is brannerite - uranium titanite, poorly soluble in acids. It contains abundant impregnation of pyrite, with a size from fractions to 10 microns. The concentrator of gold is pyrite, the gold content in it is at the level of 0.006-0.009%. The ore belongs to the class of refractory uranium ores and highly refractory gold-bearing ores, as gold has micro- and submicroscopic fineness and is finely associated with pyrite. The host rocks are characterized by a high content of acid-intensive minerals - carbonates, mica and chlorites.

The pyrometallurgical (roasting) and hydrometallurgical methods (propaganda, heap, underground, bacterial leaching) of the conversion of uranium into the aqueous phase are known, including using “reagent-free” radiation-chemical technology (Pat. RF No. 2323277 / Zaitseva A.V., Petrenko V .V., Pirkovsky S.A. et al. // Bull. No. 16, 2008).

Testing of these methods in relation to ores of the Elkon uranium ore region has shown that direct processing is the most economical technology, taking into account the forms in which uranium and gold are found, the nature of their association with ore-forming minerals, the material and mineralogical composition, and the need for processing in permafrost sulfide uranium ores in autoclaves.

The closest to the claimed technical essence and the achieved results is a method of processing uranium gold-containing materials, including grinding material to a particle size of 84% class -0.074 mm, sulfide flotation, sulfuric acid leaching of uranium from pyrite gold-uranium-containing concentrate, oxidative firing of cake after uranium leaching, extraction uranium from the aqueous phase by liquid extraction, the extraction of gold from cinder and tailings of sulfide flotation by cyanidation (Lodeishchikov V.V. value of gold and silver from refractory ores. In 2 volumes. - Irkutsk: OAO Irgiredmet, 1999, v.2, p.556).

The disadvantages of the method are multi-stage, low extraction of uranium and gold, as well as harmful effects on the environment due to the release of dust, toxic gases during firing of cake and the need to capture them.

The technical result of the invention is to increase the completeness and complexity of the processing of refractory uranium-containing pyrite and precious metals materials, increasing the efficiency and environmental safety of the process.

The problem is solved in that in the proposed method for the processing of persistent uranium containing pyrite and precious metals materials, sulfuric acid leaching is subjected to the source material with a particle size of minus 0.1-0.3 mm and lead it in an autoclave until more than 95% of uranium is transferred into the solution and oxidation state pyrite not less than 50%, after separation of the uranium-containing solution from the solid phase in the form of cake, cake is conditioned by flotation of precious metals with a sulfhydryl collector and an ethoxylated compound at pH 2.5-7.0 s Acquiring a concentrate of precious metals. In this case, the sulfuric acid leaching of the starting material is carried out with sulfuric acid at a temperature of 160-180 ° C, a partial pressure of oxygen of 10-15 atm and residual acidity of 10-20 g / l or a temperature of 130-140 ° C, air pressure of 3-5 atm and residual acidity 20 g / l in the presence of a catalytic amount of nitric acid. Noble metal flotation is carried out at a particle size of the solid phase minus 0.1-0.3 mm and a pulp density of 25-35% solid or at a particle size of the solid phase minus 0.3 + 0.044 mm and a pulp density of 45-55% solid. As the ethoxylated compound using one of the reagents:

- ethoxylated alcohol of the general formula: C _n H _{2n + 1} O (C ₂ H ₄ O) _m H, where n = 8-20, m = 6-100, including the reagent bearing the DS-10 trademark, where n = 10-18, m = 8-10 or a reagent bearing the brand name "Drug OS-20", where n = 14-18, m = 20;

- ethoxylated alkyl phenol of the general formula: C _n H _{2n + 1} C ₆ H ₅ O (C ₂ H ₄ O) _m H, where n = 8-10, m = 4-20, including the reagent bearing the trademark Neonol AF 9-6 ", where n = 8-10, m = 6;

- ethoxylated acid of the general formula: C _n H _{2n + 1} COO (C ₂ H ₄ O) _m H, where n = 11-20, m = 5-10, including the reagent bearing the brand name "Laurox-9" ( L-9), where n = 11, m = 9;

- polyethylene glycol of the general formula: - (OS ₂ H ₄ -) _m , where m = 4-60, including the reagent bearing the PEG-1500 trademark (m = 32);

- organophosphorus compound of the general formula: [RO (C ₂ H ₄ O) _m ] ₂ P (O) OM, where R is C _4-20 alkyl, C ( _8-10 ) alkyl, phenyl, MH, K, HN ( CH ₂ CH ₂ OH) ₃ , m = 4-12, including the reagent bearing the Meteks trademark (MT, R is C ₉ phenyl alkyl, M = K, m = 10) or the reagent having the Oxifos metal trademark B "(OB, R is alkyl C _8-10 , M = K, m = 6).

The difference of the proposed method from the prototype method lies primarily in the conditions of the opening of uranium minerals and gold minerals.

In the prototype method, the sulfuric acid leaching of uranium, represented mainly by uraninite, is carried out in packs of hot sulfuric acid. Moreover, uranium recovery is only 20%.

To open the refractory gold in a known method, oxidative calcination of gold-containing pyrite (cake after leaching of uranium) is used to obtain a gold-containing concentrate (cinder). Firing cake is carried out at a temperature of 650-750 ° C. Gold recovery is 40%.

The disadvantages of firing are high energy intensity, as well as the need to capture dust and purify sulfur-containing gases, which affects the ecology of the process. In addition, in view of the low uranium recovery, an additional stage of sulfuric acid leaching is required.

In the inventive method, the leaching of uranium and the oxidation of pyrite is carried out in one stage in the following modes:

- sulfuric acid at a temperature of 160-180 ° C, a partial oxygen pressure of 10-15 atm with a residual acidity of 10-20 g / l;

- sulfuric acid in the presence of 1% nitric acid (calculated on the starting material), at a temperature of 130-140 ° C, air pressure 3-5 atm, residual acidity 20 g / l.

Increasing the concentration of sulfuric acid leads to an increase in its irrational consumption during leaching, including acid-absorbing waste rock. Therefore, the residual concentration of sulfuric acid is limited to 20 g / dm ³ . When the concentration of sulfuric acid is below 10 g / dm ^{3, the} oxidation efficiency decreases and the required degree of opening of minerals is not provided.

The selected concentration of H ₂ SO ₄ provides the opening of brannerite and the oxidation of pyrite at a temperature of 160-180 ° C.

Adding a catalytic amount of nitric acid allows leaching of refractory minerals under milder conditions (at a temperature of 130-140 ° C) due to the initiation of the process by nitrogen oxides formed during the reaction and oxidized in the water and gas phases with the formation of nitric and nitrous acids according to the reactions:

2NO + 3 / 2O ₂ + H ₂ O → 2HNO ₃

2NO + 1 / 2O ₂ + H ₂ O → 2HNO ₂ + O ₂ → 2HNO ₃ ,

In this case, nitric acid is regenerated directly in the autoclave, and the process proceeds practically without the release of nitrogen oxides into the environment.

The claimed boundaries of the temperature and pressure of oxygen correspond to the transfer of more than 95% of uranium to the solution and the degree of oxidation of pyrite is not less than 50%, with obtaining, after filtering, washing and repulping, of gold-containing cakes dumped by uranium. As an oxidizing agent, oxygen or air is used.

When autoclaved leaching of persistent uranium gold-bearing materials in the claimed conditions, the following processes occur:

- uranium (IV) is oxidized to uranium (VI), which goes into solution and is then extracted from the aqueous phase by known methods;

- iron (II) is oxidized to iron (III), sulfide sulfur is oxidized to sulfate sulfur:

2FeS ₂ + 71 / 2O ₂ + Н ₂ O = Fe ₂ (SO ₄ ) ₃ + Н ₂ O

The resulting ferric sulfate undergoes hydrolysis with the formation of iron hydroxide and basic iron sulfate. Iron hydroxide, when the temperature rises above 130 ° C, loses water and passes into hematite:

Fe ₂ (SO ₄ ) ₃ + (3 + n) Н ₂ O = Fe ₂ O ₃ nH ₂ O + 3H ₂ SO ₄

Fe ₂ (SO ₄ ) ₃ + (2 + 2n) H ₂ O = 2 [Fe (OH) SO ₄ · nH ₂ O] + H ₂ SO ₄

Fe ₂ O ₃ · nH ₂ O = Fe ₂ O ₃ + H ₂ O

As a result of the oxidation of gold-containing pyrite in the conditions of the proposed method, secondary gold is formed, the particles of which are nanometer in size and are closely associated with iron hydroxide. Gold after sulfuric acid leaching of uranium is floated and extracted from the concentrate by known methods.

The choice of autoclave leaching parameters corresponds to the maximum high speed of the process and the degree of decomposition of the most resistant uranium minerals is more than 95% and the degree of oxidation of pyrite is at least 50%, which determines the increased recovery of precious metals during subsequent flotation enrichment. Leaching cakes are uranium dump (uranium content <0.01%) and contain 1.0-1.5 g / t gold and 12-16 g / t silver.

The degree of disclosure of uranium minerals is estimated by the results of analysis of uranium in the aqueous phase and leach cake, the degree of disclosure of pyrite is determined by analysis of sulfide sulfur in the initial product and leach cake.

Thus, the advantage of the autoclave version of leaching of uranium and oxidation of pyrite compared with the prototype method is the high degree of opening of the resistant minerals of uranium and gold, which allows you to translate more than 95% of uranium into solution and oxidize pyrite by at least 50%. In addition, the inventive method is more economical and environmentally friendly.

Another difference of the proposed method from the prototype method lies in the sequence of operations flotation of sulfides - leaching of uranium.

The flotation of sulfides in the prototype method is carried out before leaching of uranium. For processing refractory uranium gold-bearing ores of the Elkon deposit, when uranium and gold minerals are not available for interaction with flotation reagents, this sequence of operations is not suitable. The flotation of precious metals should be carried out only after autoclave leaching, when the most resistant uranium mineral, brannerite, and the associating gold and silver pyrite are oxidized (the claimed method).

The next difference is the size of the processed material. So, the flotation of sulfides in the prototype method is carried out at a particle size of the solid phase of 84% of the class -0.074 mm

In the proposed method, flotation is carried out at a particle size of the solid phase minus 0.1-0.3 mm and a pulp density of 25-35% or at a particle size of the solid phase minus 0.3 + 0.044 mm and a pulp density of 45-55% without additional costly grinding. This greatly simplifies the hydrometallurgical redistribution scheme: a material of this size is quickly filtered and does not require the introduction of additional reagents. Therefore, the flotation of gold in the conditions of the proposed method (on a larger material and in a denser pulp) is economically more profitable.

The fourth difference is flotation at pH 2.5-7.0. This is technologically justified: it does not require deep washing of the cake from sulfuric acid after leaching of uranium and thickening of the pulp before flotation. In the proposed method, the cake after leaching of uranium is filtered, washed with water at T: W = 1: 1 and pulp.

And finally, in the prototype method, sulfhydryl collectors are used for the extraction of gold and sulfides: sodium mercaptobenzothiazole and sodium dithiophosphate.

In the inventive method for flotation of precious metals from cake after leaching of uranium together with sulfhydryl collectors (potassium butyl xanthogenate and sodium dibutyl dithiophosphate) use an ethoxylated compound:

- ethoxylated alcohol of the general formula: C _n H _{2n + 1} O (C ₂ H ₄ O) _m H, where n = 8-20, m = 6-100; including the reagent "DS-10" (n = 10-18, m = 8-10) and "Preparation OS-20" (n = 14-18, m = 20);

- ethoxylated alkyl phenol of the general formula: C _n H _{2n + 1} C ₆ H ₅ O (C ₂ H ₄ O) _m H, where n = 8-10, m = 4-20; including ethoxylated alkyl phenol - neonol AF 9-6 (n = 8-10, m = 6);

- ethoxylated acid of the general formula: C _n H _{2n + 1} COO (C ₂ H ₄ O) _m H, where n = 11-20, m = 5-10; including reagent "Laurox-9" (n = 11, m = 9);

- polyethylene glycol of the general formula: - (OS ₂ H ₄ -) _m , where m = 4-60; including PEG-1500 polyethylene glycol (m = 32);

- organophosphorus compound of the general formula: [RO (C ₂ H ₄ O) _m ] ₂ P (O) OM, where R is C _4-20 alkyl, C ( _8-10 ) alkyl, phenyl, M = H, K, HN ( CH ₂ CH ₂ OH) ₃ , m = 4-12; including Metex (MT, R is alkyl C ₉ phenyl, M = K, m = 10) and Oksifos B (OB, R is alkyl C _8-10 , M = K, m = 6).

The introduction of ECO to sulfhydryl collectors increases the recovery of precious metals and their stability in acidic environments.

Apparently, flotation by individual sulfhydryl collectors extracts gold in unoxidized sulfides and in a separate form, and when used together with OES, noble metal nanoparticles are additionally sorbed from the pyrite lattice and associated with iron oxide and hydroxide. This is probably one of the reasons for increasing the recovery of precious metals in concentrate.

BKK and BTF are used in quantities of 0.1 and 0.3 kg / t, respectively. ECO consumption is 0.1 kg / t.

All used in the present method, ethoxylated compounds are produced by domestic industry and are widely used in various fields of national economy.

It is known to use the ethoxylated compounds described in the proposed method for mineral processing. So ethoxylated alcohols and ethoxylated fatty acids are recommended for use in the processing of carnallite ores (US Pat. RF No. 2079378. Method for the processing of carnallite ores // Titkov SN; Panteleeva N.N .; Kololeev N.V. et al., B03D 1 / 02, 1994).

Neonols are used as:

- a dispersant in the flotation of feldspars, magnesite and phosphates using aspartic F or oleic acid as the main collectors [Mining Chemicals Flotation Reagents. Clariant, 1997, p. 19];

- emulsifier in the flotation of phosphate ores [US Pat. USA No. 4732666, MKI B03D 1/02, NCI 209-166, 1986].

- flotation regulator of fluorite and calcite [US Pat. GDR No. 140712, B03D 1/02, 1977].

Oxyphos is recommended for flotation of rare metals and tin ores [A.S. No. 1645024 (USSR). The flotation method of ores of rare metals and tin // Utkelov B.A., Gak T.L., Abdurakhmanova I.K. et al. B03D 1/014. Publ. in 1991, B.I. No. 16, Pat. No. 1451194 (Great Britain), B2H, 1976].

Phosphorus-containing reagents (Fosfenoks (FN 6B), Meteks (MT), Fosfol 10, Fosfol 10T) are declared as collectors for flotation of fluorite ores (RF Patent No. 2319550, 2008. Collector for flotation of fluorite ores B.I. No. 8, 2008. Authors: Kurkov A.V., Pastukhova I.V. B.I. No. 8, 2008,).

A positive decision was received from 08.19.09 on the application No. 2008133081 from 11.08. 2008. The method of flotation of ores of rare metals and tin. Authors: Kurkov A.V., Pastukhova I.V. (the same reagents and Oxyphos).

The use of hydroxyethylated alcohols, hydroxyethylated acids, hydroxyethylated alkyl phenols, polyethylene glycols and organo-ethylene phosphorus compounds for the processing of refractory uranium materials containing pyrite and precious metals is not known.

Thus, the distinctive features of the proposed method are:

- the implementation of the degree of conversion of uranium minerals into solution of more than 95% and the degree of oxidation of pyrite is not less than 50%, which is ensured by the conditions for autoclave leaching;

- carrying out flotation after autoclave leaching;

- flotation at pH 2.5-7.0;

- carrying out flotation at a particle size of the solid phase minus 0.1-0.3 mm and a pulp density of 25-35% about solid or at a particle size of the solid phase minus 0.3 + 0.044 mm and a pulp density of 45-55% solid;

- joint use for flotation of precious metals sulfhydryl collector and ethoxylated compounds.

The claimed method can be applied to ore after grinding it to a particle size minus 0.1-0.3 mm (example 1) or a commercial radiometric screening product (PMC), including concentrate, sorting intermediate product and an unsortable grade of -25 mm (example 2). Preliminary radiometric ore sorting makes it possible to transfer about 30% of the processed material into a dumped uranium product and reduce the load on equipment and the consumption of reagents.

The inventive method of processing refractory uranium gold materials allows you to:

- to increase the completeness and complexity of the processing of refractory uranium containing pyrite and precious metals materials by leaching uranium and oxidizing pyrite in one stage with the transfer of more than 95% uranium to the aqueous phase and not less than 50% gold to concentrate;

- increase the efficiency and environmental safety of the process by eliminating the stage of firing cake after leaching of uranium;

- reduce by 10 times the volume of the processed material by including flotation in the technological scheme after leaching of uranium and oxidation of pyrite;

- to simplify the operation of grinding material, not finishing it to a particle size of -0.074 mm;

- replace the deep washing of the cake after leaching of uranium to a neutral medium with subsequent thickening of the pulp in the operation of washing the cake with water at T: W = 1: 1, followed by pulping. This allows you to reduce the amount of washing and wastewater and to ensure the efficiency and environmental friendliness of the method as a whole;

- to increase the extraction of precious metals in the concentrate by introducing additional hydroxyethylated compounds to sulfhydryl collectors.

Thus, in the invention with a minimum number of operations, the maximum technical result is achieved - high extraction of uranium in the aqueous phase and noble metals in flotation concentrate.

Specific examples of the implementation of the method.

Example 1. Extraction of noble metals from cake after leaching of uranium from ore using SS and MT at pH 2.8, material fineness -0.1 mm and pulp density 28% solid.

For the experiments, an ore sample was used, the chemical and mineral composition of which is presented in Tables 1 and 2.

Table 1 The results of the chemical analysis of the ore sample of the Elkon deposit,% SiO ₂ TiO ₂ Al ₂ O ₃ Fe ₂ O ₃ FeO MnO MgO Cao Na ₂ O K ₂ O P ₂ O ₅ P.p.p. Amount 57.55 1,50 12.12 4.34 1.15 0,03 1.80 5.16 1,08 7.03 0.22 5.79 97.77 Au g / t Ag, g / t U SO ₄ S _total CaF ₂ CaCO ₃ Mo 0.90 11.5 0.144 0.15 2.07 1.22 7.65 0.002

table 2 The mineral composition of the ore sample of the Elkon deposit Mineral Content% Mineral Content% Kalishpat 37.87 Apatite 0.52 Quartz 22.27 Fluorite 1.22 Plagioclase 10,2 Garnet Units characters Carbonates 8.57 Wollastonite Amphiboles, 4.0 Pyrite, Marcasite 3.13 pyroxenes Biotite, 3.0 Magnetite, 2.27 phlogopite titanomagnetite chlorite ilmenite, Fe hydroxides Sericite 5,0 Minerals Ti 1,1 hydromica Barite 0.6 Minerals U 0.25

The technological scheme of the proposed method is shown in the drawing.

Ore with a particle size of 95% of the class -0.1 mm in the form of a water pulp was subjected to an autoclave oxidation treatment carried out in an acid-resistant horizontal autoclave equipped with a mechanical stirrer and temperature and pressure control systems. For oxidation, oxygen was used.

Autoclave leaching conditions: material fineness -0.1 mm, temperature 160-180 ° С, oxygen partial pressure 10-15 atm, residual sulfuric acid concentration 10-20 g / l, leaching time - 4 hours.

Kek after leaching of uranium, filtering, washing and repulping at W: T = 1: 1 was conditioned with SS and OES, the aqueous solution was directed to sorption separation of uranium.

The leach cake is uranium dump (U content 0.017%) and contains 1.3 g / t gold and 16 g / t silver.

Flotation was performed in a laboratory flotation machine of a mechanical type (Mekhanobr) with a volume of 3.9 L with a weight of 1.25 kg according to the scheme, including the main, control and cleaning operations. The duration of the main and control flotation is 20 minutes, cleaning operations - 5 minutes The fineness of the material is 0.1 mm. Pulp density 28% solid.

A mixture of BCC - 0.1 kg / t and BTF - 0.3 kg / t were used as sulfhydryl collector, and MT - 0.1 kg / t as an ethoxylated compound.

Carrying out the experiment in the conditions of example 1 provides a degree of disclosure of minerals of uranium (mainly brannerite) 97.0%, the extraction of Au from ore, characterizing the degree of disclosure of pyrite, is 56.5%.

Table 3 presents the results of flotation of precious metals from cake after leaching of uranium from ore.

Table 3

Flotation indices of uranium and precious metals from cake after leaching of uranium from ore,%

The fineness of the material is 0.1 mm. Pulp density 28% solid. pH 2.8. BKK - 0.1 kg / t, BTF - 0.3 kg / t

Enrichment products Exit Content Extraction Au g / t Ag, g / t U S _sulphide Au Ag U S _sulphide MT = 0.1 kg / t Concentrate 18.3 4.43 56.2 0,022 3,58 62.3 64.3 23,4 72.8 Tails 81.7 0.60 7.0 0.016 0.30 37.7 35.7 76.6 27,2 Cake after leaching U from ore 100.0 1.30 16,0 0.017 0.90 100.0 100.0 100.0 100.0 without MT Concentrate 13.6 4.47 61.3 0.0264 4.08 46.8 52.1 21.1 61.6 Tails 86.4 0.80 8.9 0.015 0.40 53,2 47.9 78.9 38,4 Cake after leaching U from ore 100.0 1.30 16,0 0.017 0.90 100.0 100.0 100.0 100.0

The results of the studies, shown in Table 3, show that upon flotation of precious metals from cake after leaching of uranium from ore using sulfhydryl collectors, a concentrate containing 4.47 g / t of gold and 61.3 g / t of silver was obtained during gold recovery 46 , 8% and silver 52.1%.

With the combined use of sulfhydryl collectors and MT, the extraction of gold in concentrate increases by 15.5%, silver by 12.2%.

Example 2. Extraction of noble metals from cake after leaching of uranium from a PMC commercial product using CC and MT at pH 6.8, material fineness -0.15 mm and pulp density 30% solid.

For the experiments, a sample of the commercial product RMS was used, which contains 0.35% U, 2.25% S _total. , 1.2 g / t Au and 12 g / t Ag.

A material with a particle size of 90% of the class -0.15 mm in the form of a water pulp was subjected to an autoclave oxidation treatment carried out in an acid-resistant vertical autoclave with pneumatic stirring equipped with temperature and pressure control systems. For oxidation, air was used.

Autoclave leaching conditions: material fineness -0.15 mm, nitric acid consumption - 1% per commodity product, temperature 130-140 ° С, oxygen partial pressure 3-5 atm, residual sulfuric acid concentration 20 g / l, leaching time - 4 hours.

Carrying out the experiment in the conditions of example 2 provides a degree of disclosure of minerals of uranium (mainly brannerite) 96.8%. The extraction of Au from ore, characterizing the degree of disclosure of pyrite, is 60.4%.

The leach cake is uranium dump (U content is 0.019%) and contains 1.3 g / t gold and 11.7 g / t silver.

Cake after leaching of uranium, filtering, washing and repulpation to a pulp density of 30% solid without regrinding was conditioned with SS and OES and floated noble metals at pH 6.8; the aqueous solution was directed to sorption separation of uranium.

The conditions and equipment during the flotation are the same as in example 1. The difference is that the flotation was carried out on a material with a particle size of -0.15 mm at a pulp density of 30% solid, at a pH of 6.8.

Table 4 shows the results of experiments on the extraction of gold and silver from cake after leaching of uranium from the PMC commercial product using only sulfhydryl collectors (SS) and the combined use of SS and MT.

Table 4

Indicators of flotation of gold and silver from cake after leaching of uranium from a commercial product RMS,%

The fineness of the material is 0.15 mm. Pulp density 30% solid. pH 6.8. BKK - 0.1 kg / t; BTF - 0.3 kg / t

Enrichment products Exit Content Extraction Au g / t Ag, g / t U S _sulphide Au Ag U S _sulphide MT = 0.1 kg / t Concentrate 15.3 4.6 39.1 0,03 3.00 54.1 51.1 24.2 51.6 Tails 84.7 0.7 6.8 0.017 0.51 45.9 48.9 75.8 48,4 Cake after leaching U from a commercial product PMC 100.0 1.30 11.7 0.019 0.89 100.0 100.0 100.0 100.0 without MT Concentrate 12.7 4.8 43.5 0,033 3.23 46.6 47.2 22.1 46.1 Tails 87.3 0.8 7.06 0.017 0.55 53,4 52.8 77.9 53.9 Cake after leaching U from a commercial product PMC 100.0 1.3 11.7 0.019 0.89 100.0 100.0 100.0 100.0

The results of Table 4 show that, in the presence of MT, the extraction of gold from cake after leaching of uranium from the commercial product RMS is higher by 7.5%, silver - by 3.3% compared with the extraction of gold and silver with a mixture of BCC and BTF with a close content of noble metals in concentrate.

Example 3. Extraction of precious metals from cake after leaching of uranium from a commercial product RMS using SS and OES at pH 6.0, material fineness -0.3 mm and pulp density 35% solid.

The conditions and equipment during the autoclave leaching and flotation are the same as in example 1. The difference is that the material with a particle size of -0.3 mm was fed to the autoclave leach, flotation was carried out at pH 6.0 on a material of the same size (-0 , 3 mm) with a pulp density of 35% solid, and other hydroxyethylated reagents were used instead of MT.

Table 5 shows the results of experiments on the extraction of gold and silver from cake after leaching of uranium from the commercial product RMS using SS and ethoxylated compounds (OES).

Table 5

Indicators of flotation of gold and silver from cake after leaching of uranium from a commercial product of RMS using SS and ECO

The fineness of the material is 0.3 mm. Pulp density 35% solid. pH 6.0; BKK - 0.1 kg / t; BTF - 0.3 kg / t

Enrichment products Exit, % Content, g / t Recovery% ECO Au Ag Au Ag Concentrate 18.2 4.44 60.9 62,2 69.3 OS-20 Tails 81.8 0.60 6.0 37.8 30.7 Cake after leaching U from a commercial product PMC 100.0 1.3 16,0 100.0 100.0 Concentrate 17.1 4.2 60.6 55,4 64.8 DS-10 Tails 82.9 0.7 6.8 44.6 35,2 Cake after leaching U from a commercial product PMC 100.0 1.3 16,0 100.0 100.0 Concentrate 19.3 4.0 53.6 59.6 64.7 PEG 1500 Tails 80.7 0.65 7.0 40,4 35.3 Cake after leaching U from a commercial product PMC 100.0 1.3 16,0 100.0 100.0 Concentrate 19.6 3.35 48.8 50,5 59.8 AF 9-6 Tails 80,4 0.8 8.0 49.5 40,2 Cake after leaching U from a commercial product PMC 100.0 1.3 16,0 100.0 100.0 Concentrate 25,2 2.79 46.7 54.0 71.9 ABOUT Tails 74.8 0.8 6.0 46.0 28.1 Cake after leaching U from a commercial product PMC 100.0 1.3 16,0 100.0 100.0 Concentrate 21.0 3.18 49.8 51,4 65,4 L-9 Tails 79.0 0.8 7.0 48.6 34.6 Cake after leaching U from a commercial product PMC 100.0 1.3 16,0 100.0 100.0 Concentrate 13.6 4.47 61.3 46.8 52.1 - Tails 86.4 0.80 8.9 53,2 47.9 Cake after leaching U from a commercial product PMC 100.0 1.30 16,0 100.0 100.0

The results of Table 5 show that, when sulfhydryl collectors and OES are used together, the extraction of gold into concentrate during flotation of precious metals from cake after leaching of uranium from the PMC product is at the level of 50-62%, silver - 60-72%, i.e. 3.7-5.4% higher for gold and 7.7-19.8% higher for silver than without ECO. In this case, the maximum recovery of gold is observed with the use of MT and OS-20 reagents, and silver is better recovered by the addition of Oxyphos B. to sulfhydryl collectors.

Example 4. Extraction of precious metals from cake after leaching of uranium from a commercial product RMS using SS and OS-20 at pH 6.0, material fineness -0.3 + 0.044 mm and pulp density 50% solid (flash flotation).

For the experiments, a sample of the commercial product RMS was used, which contains 0.35% U, 2.25% S _total. , 1.2 g / t Au and 12 g / t Ag.

Material with a particle size of 95% class — 0.3 mm in the form of an aqueous pulp was subjected to an autoclave oxidation treatment under the conditions of Example 2.

The oxidized product is classified into sand and sludge. Sands (material with a grain size of -0.3 + 0.044 mm) after filtering (cake), washing and repulping to a density of 50% solid are conditioned with SS and OS-20 and flash flotation of noble materials is carried out, followed by their separation from the concentrate by known methods. The sludge after classification of the leaching product (material with a particle size of -0.044 mm) and the aqueous solution after filtration are sent to the sorption separation of uranium.

Flotation conditions: pH 6.0, material fineness of -0.3 + 0.044 mm at a pulp density of 50% solid. Reagent consumption, kg / t: BCC - 0.05; BTF - 0.15, OS-20 - 0.05. The duration of the main and control flotation is 10 minutes, the cleaning operation is 3 minutes.

Table 6 shows the results of experiments on the extraction of gold and silver from cake after leaching of uranium from a commercial product RMS using SS and OS-20.

Table 6 Indicators of flotation of gold and silver from cake after leaching of uranium from a commercial product PMC using SS and OS-20 in a dense pulp BCC - 0.05 kg / t; BTF -0.15 kg / t Enrichment products Exit, % Content, g / t Recovery% Flotation conditions Au Ag Au Ag Concentrate 10.7 8.44 68.7 66.9 61.3 Pulp density 50% tv. pH 6.0. Fineness -0.3 + 0.044 mm. OS-20 - 0.05 kg / t Tails 89.3 0.5 5.2 33.1 38.7 Cake after leaching U from a commercial product PMC 100.0 1.35 12.0 61.3 100.0 Concentrate 18.2 4.44 60.9 62,2 69.3 Pulp density 35% tv. pH 6.0. Fineness - 0.3 mm. OS - 20-0.1 kg / t Tails 81.8 0.60 6.0 37.8 30.7 Cake after leaching U from a commercial product PMC 100.0 1.3 16,0 100.0 100.0

The results of Table 6 show that flotation of precious metals from cake after leaching of uranium from a PMC product using CC and OS-20 in a dense pulp allows one to obtain high technological parameters for the extraction of gold and silver while reducing reagent consumption and flotation time by 2 times . In addition, flotation in a dense pulp proceeds more selectively: the gold content in the concentrate is 1.9 times higher than at a pulp density of 35%.

Example 5. Extraction of platinum and palladium from cake after leaching of uranium from the commercial product PMC.

For the experiments, cake was used after leaching of uranium from the PMC commercial product having the following composition, g / t: Pt - 0.03; Pd - 0.042; Au - 1.15; Ag - 16.0; U - 0.018%; S _sulfide - 1.35%.

The conditions and equipment during autoclave leaching and flotation are the same as in Example 2. After the uranium was leached, filtered, washed and repulped to a pulp density of 30% solid, platinum and palladium were floated from the cake. The flotation results are shown in table.7.

Table 7

Flotation indices of platinum and palladium from cake after leaching of uranium from the PMC commercial product at pH 6.8 and using CC and MT

The fineness of the material is 0.15 mm. Pulp density 30% solid.

Enrichment products Exit, % Content Extraction Reagent consumption, kg / t Pt, g / t Pd g / t Pt,% Pd% Concentrate 11.3 0.16 0.30 62.9 76.1 BKK-0,1; Tails 88.7 0.012 0.012 37.1 23.9 BTF-0.3; Cake after leaching U from a commercial product PMC 100.0 0,0287 0.0445 100.0 100.0 MT-0.1 Concentrate 11.0 0.12 0.22 55.3 69,4 BKK-0,1;
BTF-0.3 Tails 89.0 0.012 0.012 44.7 30.6 Cake after leaching U from a commercial product PMC 100.0 0.024 0,035 100.0 100.0

The results of table 7 show that the inventive method can effectively extract not only gold and silver (Table 4 and 5), but also platinum and palladium from the cake after leaching of uranium from the PMC product. In the presence of an OES (for example, MT), the extraction of platinum and palladium is 7.6 and 6.7% higher, and the content of these metals in the concentrate is higher by 0.04 and 0.08 g / t, respectively, than in their absence.

Thus, the inventive method makes it possible to involve in the processing and production of uranium and gold additional sources of raw materials - refractory ores of unconventional deposits of the Elkonsky gold-uranium region.

As starting materials can be: ore, commercial product RMS and other products of its enrichment.

The above examples indicate that the proposed method, regardless of the nature of the used source uranium gold-containing materials, provides high extraction of uranium in the aqueous phase and noble metals in the collective concentrate.

An additional introduction to the traditionally used sulfhydryl collectors of ethoxylated compounds during the flotation of precious metals from cakes after leaching of uranium from a commercial product of PMC allows to increase the recovery of gold in concentrate by 3.7-7.5%; silver by 7.7-19.8%, platinum by 7.6% and palladium by 6.7%.

The combined use of sulfhydryl collectors and MT in the flotation of precious metals from cakes after leaching of uranium from ore leads to an increase in the extraction of gold in concentrate by 15.5%, silver - by 12.2%.

The reagents used in the inventive method are produced by the domestic industry in significant quantities, they are not toxic and not explosive.

Flotation of precious metals from cake after leaching of uranium from a PMC product in dense pulp (at a pulp density of 45-55% solid) with the combined use of SS and OES allows to obtain higher technological parameters for the extraction of gold and silver while reducing reagent consumption and flotation time 2 times.

The research results indicate the high efficiency and versatility of the proposed method for the enrichment of persistent uranium gold-containing materials.

The inventive method can be recommended for the industrial processing of refractory uranium gold-bearing materials in the processing plants, including for the processing of ores of the Aldan ore field and other samples of ores of the Elkonsky gold-uranium district (Yuzhnaya zone - Elkon, Kurung sections).

The commercialization of refractory complex uranium gold-bearing ores of the Elkonskoye deposit will ensure the main increase in uranium production in the Russian Federation with the integrated extraction of uranium, gold, silver, platinum and palladium.

Claims (17)

1. A method of processing refractory uranium containing pyrite and precious metals materials to extract uranium and obtain a concentrate of noble metals, including sulfuric acid leaching of uranium, characterized in that the sulfuric acid leaching is subjected to the source material with a particle size of minus 0.1-0.3 mm and lead it in an autoclave until more than 95% of uranium is transferred to the solution and the pyrite oxidation state is at least 50%, after separation of the uranium-containing solution from the solid phase in the form of cake, cake is conditioned by flotation of noble metals thallium with sulfhydryl collector and ethoxylated compound at pH 2.5-7.0 to give a precious metal concentrate. 2. The method according to claim 1, characterized in that the sulfuric acid leaching of the starting material is carried out with sulfuric acid at a temperature of 130-140 ° C, an air pressure of 3-5 atm and a residual acidity of 20 g / l in the presence of a catalytic amount of nitric acid. 3. The method according to claim 1, characterized in that the leaching of the starting material is carried out with sulfuric acid at a temperature of 160-180 ° C, a partial oxygen pressure of 10-15 atm and a residual acidity of 10-20 g / L. 4. The method according to claim 1, characterized in that as the ethoxylated compounds use ethoxylated alcohol of the General formula:
C _n H _{2n + 1} O (C ₂ H ₄ O) _m H, where n = 8-20, m = 6-100. 5. The method according to claim 4, characterized in that the reagent having the trademark "DS-10", where n = 10-18, m = 8-10, is used as ethoxylated alcohol. 6. The method according to claim 4, characterized in that as the ethoxylated alcohol, a reagent having the brand name “Drug OS-20” is used, where n = 14-18, m = 20. 7. The method according to claim 1, characterized in that the alkylated phenol of the general formula is used as the ethoxylated compound: C _n H _{2n + 1} C ₆ H ₅ O (C ₂ H ₄ O) _m H, where n = 8-10, m = 4-20. 8. The method according to claim 7, characterized in that as a hydroxyethylated alkyl phenol, a reagent having the trademark "Neonol AF 9-6" is used, where n = 8-10, m = 6. 9. The method according to claim 1, characterized in that as an ethoxylated compound, an ethoxylated acid of the general formula is used:
C _n H _{2n + 1} COO (C ₂ H ₄ O) _m H, where n = 11-20, m = 5-10. 10. The method according to claim 9, characterized in that as a hydroxyethylated acid, a reagent having the brand name "Laurox-9" (L-9) is used, where n = 11, m = 9. 11. The method according to claim 1, characterized in that as the ethoxylated compounds using polyethylene glycol of the General formula: - (OS ₂ H ₄ -) _m , where m = 4-60. 12. The method according to claim 11, characterized in that the polyethylene glycol used is a reagent having the trademark "PEG-1500", where m = 32. 13. The method according to claim 1, characterized in that the organophosphorus compound of the general formula: [RO (C ₂ H ₄ O) _m ] ₂ P (O) OM, where R is C _4-20 alkyl, alkyl (C _8-10 ) phenyl, where M is H, K, HN (CH ₂ CH ₂ OH) ₃ , m = 4-12. 14. The method according to p. 13, characterized in that the organophosphorus compound used is a reagent bearing the brand name Metex (MT), where R is alkyl C ₉ phenyl, M = K, m = 10. 15. The method according to item 13, wherein the organophosphorus compound is a reagent having the trademark Oxyphos B (OB), where R is alkyl C _8-10 , M = K, m = 6. 16. The method according to claim 1, characterized in that the flotation of precious metals is carried out at a particle size of the solid phase minus 0.1-0.3 mm and a pulp density of 25-35% solid. 17. The method according to claim 1, characterized in that the flotation of precious metals is carried out at a particle size of the solid phase (-0.3) - (+0.044) mm and a pulp density of 45-55% solid.

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