EA026961B1 - Method for processing metal-containing materials including ores, technogenic materials and metallurgical industry process wastes - Google Patents

Abstract

The invention is related to metallurgy, namely, to methods for processing of ores, technogenic materials and metallurgical industry process wastes. It can be used in metallurgy, in ores and technogenic materials leaching processes, for extraction of ferrous, non-ferrous, noble metals and rare-earth elements to water-soluble complexes. The method for processing of metal-containing materials includes source material grinding and treatment with a leaching agent. The leaching agent used is 5-10% hydrochloric acid solution earlier subjected to anode-cathode activation in a special module at a current intensity of 10-16 A producing gas-condensate oxidant mix and hydrogen. The oxidant mix is fed to a reactor containing raw material for leaching. The leaching process is run under normal conditions with continuous stirring during 1-5 h. Hydrogen from the acid activation module is discharged, through a special valve, to the pyrosynthesis chamber, this chamber receiving also excessive chlorine from the leaching stage; in the chamber, at a temperature of 400°C, synthesis takes place that produces hydrochloric acid which, after dilution with water, is introduced into the activation process again. To achieve complete leaching of the raw material, relationship between hydrochloric acid and the source material being processed must correspond to the ratio S:L=1:1.5. Suspension produced after leaching is filtered to produce cake and enriched electrolyte. The electrolyte is subjected to the electric extraction process to obtaine the target product.

Description

The invention relates to metallurgy, and in particular to methods of processing ores, industrial materials and technological wastes of the metallurgical industry. It can be used in hydrometallurgy, in the leaching of ores and industrial materials, for the extraction of ferrous, non-ferrous, noble metals, as well as rare-earth elements in water-soluble complexes.

There is a method and composition for extracting gold from ores into an aqueous solution for leaching gold using sodium or potassium hypochlorites (application 5026132/03, 1991.11.26, Blokhin N.N .; Fedotov G.P .; Khmelevskaya G.A. and others .). Immediately before being fed into the ore, the hydrochloric acid solution is neutralized by adding a solution of salable alkaline sodium or potassium hypochlorite to it. Use sodium hypochlorite (TU-6-15-746-87) or obtained by electrolysis. A solution of sodium hypochlorite (TU-6-15-746-87) is served in an amount of 0.6 vol. at 1-4 about. hydrochloric acid solution.

The disadvantages of the method include the consumption of a large amount of sodium or potassium hypochlorites, necessary to neutralize the pH level and the allocation of atomic chlorine;

a neutral environment promotes the release of a large amount of arsenic into the solution, which pollutes the solution and subsequently is released at the cathode during electroextraction, while being a potent poison;

gold yield is 85%.

A known method of complex processing of aluminosilicate raw materials (application 2007143435/15, 05.27.2009, Kosmukhambetov A.R., Kaniev B.S.). Ore is sintered with sodium carbonate and sodium hydroxide, the resulting cake is leached with a hydrochloric acid solution. The pulp obtained by leaching is separated to obtain a chloride solution and a solid residue. More electropositive metals than aluminum are isolated from the chloride solution in an electrolyzer with a separated anode and cathode space at a cathodic current density of at least 500 A / m ² . After that, the purified chloride solution is subjected to heat treatment to obtain a product containing aluminum and sodium oxides and a hydrochloric acid solution. The solid leach residue is dissolved in an alkaline solution, and the resulting solution is carbonized to give a solution of sodium carbonate and a precipitate of amorphous silica. Purified from more electropositive metals than aluminum, the chloride solution is subjected to heat treatment with evaporation of the solution and obtaining aluminum chloride hexahydrate in the first stage, calcining it at 400-600 ° С to obtain a product containing aluminum and sodium oxides in the second stage and condensing the solution hydrochloric acid from heat treatment gases. The feedstock is pre-treated with a solution of hydrochloric acid, after which the solution is separated from the solid residue, which is washed with water and fed to sintering, and the chloride solution is processed to obtain an iron-containing product.

The disadvantages of the method include the presence of pyrometallurgy in the method, which necessitates the construction of furnaces with a temperature of 500 ° C, as well as evaporators;

the use of a highly concentrated hydrochloric acid solution (250 g / dm ³ ); ratio W: T = (2.5-3): 1, i.e. very large water circulation;

copper recovery in the process was 94%; precious metals recovery was not indicated.

Closest to the claimed invention is a method of processing waste containing copper, zinc, silver and gold, including leaching of copper, zinc, silver and gold in the presence of a chlorine-containing oxidizing agent, followed by extraction of metals from the resulting solution. Leaching of copper, zinc, silver and gold in the presence of a chlorine-containing oxidizing agent is carried out with alkaline ammonia-salt solutions. As a leaching agent, alkaline ammonia-salt solutions containing oxidizing agents having complexing properties are used. As an oxidizing agent, active chlorine is used, which is dosed into the leach pulp in the form of hypochlorite to maintain the oxidation potential. Thus, immediately before being fed into the material, ammonia-salt solutions are mixed with a solution of hypochlorites and the oxidation potential necessary for transferring metals to the solution is controlled. The solid and liquid phases are then separated. Then, the resulting liquid phase is sent for electroextraction. (Application number: 96102649/02, class С22В7 / 00, С22В11 / 00, authors: Verevkin G.V .; Denisov V.V .; Buzlaev Yu.M.).

The disadvantages of the method include the need to use hypochlorites, ammonia and ammonium salts, which is associated with additional economic costs for their purchase, delivery and storage;

the need to use selective, for each specific element, organic and inorganic reagents.

The authors were faced with the task of developing a universal method of processing metal-containing materials suitable for both poor and rich ores, for processing technogenic materials and wastes of the metallurgical industry, which allows to increase the amount of elements recovered in the solution and at the same time being quite economical, as well as to reduce the leaching time and transferring the target components to the solution.

A method for processing metal-containing materials is proposed, including grinding the initial 1,026,961 material and treating it with a leaching agent. As a leaching agent, a 5-10% solution of hydrochloric acid, previously subjected to anodic-cathodic activation in a special module at a current strength of 10-16 A to obtain a gas-condensate oxidant mixture and hydrogen, is used. The oxidant mixture is fed into the leach reactor. The leaching process is carried out under normal conditions and with constant stirring for 1-5 hours. Hydrogen from the acid activation module is diverted through a special valve to the pyrosynthesis chamber, excess chlorine is fed into the chamber from the leaching stage, and synthesis occurs at 400 ° C with the formation of hydrochloric acid acid, which after dilution with water is again introduced into the activation process. To achieve complete leaching of the starting material, the ratio of hydrochloric acid to the starting material to be treated must correspond to the ratio T: W = 1: 1.5. After leaching, a suspension is obtained, filtered, obtaining cake and enriched electrolyte. The electrolyte is subjected to an electroextraction process to obtain the desired product.

The technical result is achieved due to the totality of the claimed features.

New and non-obvious is that the hydrochloric acid solution used as the leaching agent is preliminarily subjected to anodic-cathodic activation. The result is a gas-condensate mixture of oxidants, which, with a constant supply to the reactor with the starting material, allows leaching of the starting material. It is unexpected that leaching is so complete that both poor and rich ores, industrial materials, and waste from the metallurgical industry can be used as starting material. The state and formation of oxygen radicals of the electroactivation process, as well as hypochlorous acid in aqueous solutions of hydrochloric acid, looks like this:

Н ₂ О + С1 ₂ - (НСУ) + НС1 - 2НС1 + О 'Еа _its = -2.77 V

Hypochlorous acid is very unstable and subsequently passes into hydrochloric acid. The oxygen radical formed by itself has an electric potential of -2.77 V, which makes it possible to oxidize and convert gold, platinum, palladium, rhodium and other hardly soluble metals into water-soluble compounds. As a result, metal chlorides are formed, including complexes, depending on their valencies AiC1, AiC1 ₃ , CuC1, AdC1 and others. Together with parallel reactions and the formation of active compounds and radicals, the mixture has very high oxidizing properties. The chemistry of the reactions is as follows:

No. С1 + Н ₂ О -е -> ΝαΟΗ + 0.5 Н ₂ + 0.5 С1 ₂ Е _а «= - 2.20 V

2КаС1 + 6Н ₂ О - 10е 2С1О ₂ + 2ΝαΟΗ + 5 Н ₂ Е ₄ , _g = 1.74 V

2H ₂ O - 4e> 2H ₂ + O ₂ O as ZN - 6e> ZN ₂ O ₃ + E _Lk = -1,60 V

Leaching according to this technology does not require a high degree of grinding of the material, since the agent itself is a gas condensate mixture. Therefore, the optimum degree of grinding is a material fineness of -1 mm (minus 1 mm) 80%, this on the one hand allows you to open most of the ore and the precious and rare-earth metals interrupted in it, and on the other hand, simplifies the filtering process. The particle size of the starting material, for example, for ore, is -1 mm (minus 1 mm) 80% much more technologically advanced than the traditional flotation pulp, which is by industry standards 0.074 microns 60-80%. An important stage is the mixing process, the material of which the reactor is made and the design of the reactor are important, since the medium is very aggressive and is able to dissolve almost all metals, including legiars.

For leaching, a reactor is used, which should be made of fluoroplastic, or from combined sandwich structures made of metal, fluoroplastic and polymers. Traditional lining is also possible. Allowed the use of Teflon and vinyl, traditional for industry. Mixing is also carried out in a combined way and may include mechanical mixing, aeration mixing, bubble-type mixing, comb mixing, mixing with special paste pumps, as well as the use of other methods and types of contact and non-contact mixing. By using the preliminary activation of hydrochloric acid and obtaining the strongest oxidant mixture, the technology does not require heating the reactor or creating additional pressure. The entire leaching process is carried out under normal conditions. The production of 1 kg of oxidants in terms of chlorine requires 2.5 kW / h, this amount is enough to leach 400-700 kg of material per hour, depending on the composition of the leach material. As working examples of installations for the electroactivation of solutions, the installations described in the following sources can be used: Bahir V.M., KP and KP 2181106, Key Plitman V.L .; Krymsky V.V.

All of the above indicates that the claimed method is universal and quite simple in comparison with the methods of leaching materials known from the prior art.

In FIG. 1 is a flow diagram of a cyclic laboratory process.

The technological scheme of the process is described in stages below.

1. A concentrated solution of rock salt is fed into a special electrolyzer, where it occurs

- 2 026961 decomposition of rock salt into hydrochloric acid (HC1) and caustic (ΝαΟΗ) in a volume of approximately 1: 1. Caustic is separated.

2. HC1 solution 5-10% is fed into the storage tank at a given speed, this ensures constant maintenance and control of the concentration and volume of hydrochloric acid supplied to the preliminary electrochemical module (TEM) of the hydrochloric acid electroactivation unit (UECC).

3-4. Then the HC1 solution of 5-10% enters the preliminary electrochemical module (TEM), where the anodic-cathodic electroactivation of the hydrochloric acid solution takes place with the release of a large amount of oxidants (such as C1, C1 ₂ , C1 ₃ , O, O ₂ , O ₃ , and also chlorine oxides), radicals and hydrogen. Hydrogen is discharged into the pyrosynthesis chamber of hydrochloric acid.

5. A gas-condensate mixture of oxidants is fed into the reactor and saturates the material in it with chlorine, the saturation process proceeds with constant stirring. To completely remove the remaining excess chlorine (by sampling) at the end of the process, the reactor is purged with air. The process is carried out for 1-5 hours (at a concentration of HC1 10% in the supply to the TEM, even the most resistant materials are leached out completely). Excess chlorine through a special valve enters the pyrosynthesis chamber.

6. Hydrogen chloride is synthesized in a pyrosynthesis chamber at a temperature of 400 ° C, which, with an adjusted supply of chlorine, ensures complete combustion of chlorine in hydrogen by reaction

C1 ₂ + H ₂ —400С ° - 2НС1

For reliability, special gas cylinders are installed through which, under atmospheric pressure or slightly higher, it is possible to accumulate and supply agents (chlorine and hydrogen). Thus, the regeneration of excess chlorine into hydrochloric acid is carried out.

7. After the end of the leaching process, as judged by sampling, the enriched suspension with a special pump through the valve is output to the filtration. This system must be airtight to prevent chlorine leakage.

8. During the filtration process, cake and an electrolyte solution are formed.

In suspension, the ratio Liquid: Solid, when applied to the filtration, is approximately 1: 1.5. Those. after filtering the suspension, we get about 1000 ml of electrolyte per 1 kg of cake at a cake humidity of 5%. That allows you to get a fairly concentrated solution of electrolyte for electrolysis.

The metal-containing material is pre-crushed to a particle size of -1 mm (minus one) 80%. A sample of material weighing 2.5 kg is placed in a reactor equipped with a mixing device. The hydrochloric acid solution from the storage tank is fed to an electroactivation unit equipped with anodic-cathodic electrochemical modules. Electroactivation takes place at a current strength of 10-16 A. Hydrogen generated at the cathode is constantly removed from the modules into the pyrosynthesis chamber. At the same time, the valve for supplying the electroactivated solution (oxidant) from the activating module to the reactor with the starting material is opened. The material is saturated with a gas condensate oxidant and the leaching of metals occurs. Excessive active chlorine from the reactor through a slide valve enters the pyrosynthesis chamber. In the pyrosynthesis chamber at 400 ° C, hydrogen and chlorine are synthesized with the formation of hydrogen chloride. From the pyrosynthesis chamber, hydrogen chloride is diverted to a receiver filled with water, where it is cooled and diluted to obtain hydrochloric acid up to 5-10%. From the receiver, the resulting hydrochloric acid solution is fed back to the electrochemical activation modules. The process of leaching the material takes from 1 to 5 hours, depending on the elemental composition of the material. The reactor is equipped with a valve pocket, through which samples are taken for analysis every 30 minutes, according to which the end of the leaching process is judged. Then, the entire suspension formed is pumped to filtration, where the cake and the electrolyte solution enriched with valuable components are separated. Next, the solution is supplied for electroextraction.

The enriched electrolyte solution from the filtration process can be implemented as an intermediate or can be submitted for electroextraction and electrolysis. Previously, before electrolysis is supplied, the volume of the electrolyte can, and if necessary, with a low metal content in the starting material, be reduced. This is achieved by removing accompanying impurities on ion-exchange resins, or by collecting the target components on ion-exchange resins, by introducing membranes or diaphragms with reverse osmosis technology into the process, and also by using other methods of concentration of the electrolyte solution, including evaporation, vacuum evaporation, distillation processes and others. This system must be airtight and have good ventilation.

Below are examples of specific experiments on various metal-containing materials.

For all materials, a single leaching regime was used, optimal according to the results of preliminary studies. The difference is established only for the leaching time necessary for the complete extraction of elements into the solution and depending on the composition of the material.

- 3,026,961

Example 1

Sulfide ore was used. Leaching time was 170 minutes. The chemical composition of the experimental ore

No. pp Name Content,%, g / t Si Aw g / t g / t P ^ rO} CaO mgo A1 ₂ o ₃ 5U ₂ ^ general ⁸ ds = 1111 and one Sulfide Ore Composite Sample 0.58 0.8 3.04 3.22 3.57 2.15 15.07 64.48 0.48 0.44 0.04 1.2

The chemical composition of the cake after the leaching process

No. P P Name Content,%. g / t Si Aw g / t Ayo g / t LUO-. CaO . \ 1 "About A1, O ₃ 5U ₂ 5rbsch 5 ₃ ⁸ 50 ' ΙΪΠ11 one Residual content in cake after leaching 0.004 0,052 0.18 1.17 2.01 0.73 4.92 61.7 0.21 n / a n / a

Example 2

Oxidized ore was used. Leaching time was 75 minutes. The chemical composition of the experimental ore

Clinker was used.

Leaching time was 211 minutes. The chemical composition of clinker

- 4,069,961

The chemical composition of the used tailings

No. P P Name Content,%, g / t Si Ai g / t g / t Re ₂ About ₃ CaO MgO ABOz 5ίΟ ₂ <5. ° ΟΟΙΙ | $ 5 Org one Composite test oxidized ore 0.21 0.9 4.71 3.39 4.42 3.25 3.07 45.55 18.5 n \ n 0.37

The chemical composition of the cake after the leaching process

No. No. P P Name Content,%, g / t Si Ai g / t Ag g / t Ate CaO Mvo Battery SJ ₂ 5total Org one Residual content in cake after leaching 0.001 0.004 0.035 1.33 0.95 0.18 1.11 42.20 15.1 n / a 0.10

The practical recovery of the target metals from ore for copper, silver and gold was 99, 94 and

93% respectively. Losses fit into the technological schedule and are due to the low efficiency of the filter elements used, insufficient grinding to completely leach gold and silver in the interstitium, as well as a completely possible analytical error.

Leaching according to this technology does not require a high degree of grinding of the material, since the agent itself is a gas condensate mixture. Therefore, the optimum degree of grinding is a material fineness of -1 mm (minus 1 mm) 80%, this, on the one hand, will allow to reveal most of the material, including ores and precious and rare-earth metals intersted in them, and on the other hand, it will simplify the filtration process. Particle size -1 mm (minus 1 mm) 80% is much more technological than flotation pulp, which is, according to traditional industry standards, 0.074 microns 60-80%. The technology does not require heating the reactor or creating additional pressure. The entire leaching process is carried out under normal conditions. The production of 1 kg of oxidants in terms of chlorine requires 2.5 kW / h, this amount is enough to leach 400-700 kg of material per hour, depending on the composition of the leach material.

Claims (6)

CLAIM 1. A method of processing metal-containing materials, including grinding the material, treating it with a leaching agent, filtering the resulting suspension to obtain cake and electrolyte and feeding the latter to electroextraction to obtain the target product, characterized in that a 5-10% solution is used as the leaching agent hydrochloric acid, which is preliminarily subjected to anodic-cathodic electroactivation in a special module with a current strength of 1016 A to obtain a gas condensate oxidant mixture and hydrogen, the oxidant mixture is fed into the reactor with the leachate starting material with the formation of excess chlorine, while leaching is carried out for 1-5 hours under normal conditions and the ratio of hydrochloric acid fed to electroactivation to the starting material to be processed is preliminarily calculated using known methods taking into account the quantitative elemental the composition of the material for complete leaching. 2. The method according to claim 1, characterized in that the source material is ground to a particle size of -1 (minus one) mm 80%. 3. The method according to claim 1, characterized in that the excess chlorine from the leaching stage and hydrogen from the specified electrochemical module through a special valve is fed into the pyrosynthesis chamber. 4. The method according to claim 3, characterized in that the temperature in the pyrosynthesis chamber is maintained within 400 ° C. 5. The method according to claim 3, characterized in that the newly synthesized hydrogen chloride is fed to the receiver with water for cooling and diluting it to a concentration of 5-10% to obtain hydrochloric acid. 6. The method according to claim 5, characterized in that the resulting hydrochloric acid is again fed to electroactivation for subsequent leaching.