RU2763088C1 - Method for extraction of copper from sulfide and mixed (sulfide and oxidized) ores with associated extraction of precious metals - Google Patents

Abstract

FIELD: non-ferrous metallurgy.

SUBSTANCE: invention relates to the extraction of non-ferrous and precious metals from ores, in particular from sulfide and oxidized copper ores. The method includes crushing the ore to a fineness class of -630 + 160 microns, leaching of copper and precious metals with a solution containing, g/l: copper (II) chloride 2-aqueous 200-300, sodium chloride 150-300 or a solution containing, g/l: copper (II) chloride anhydrous 20-100, sodium chloride 100-200, iron (III) chloride 6-aqueous 50-150. The pH of the solution is 1.0 - 1.9. After that, the solid leaching waste from the solution residues is washed with water, sorption, extraction, re-extraction and electrolysis are carried out. Leaching and washing of solid leaching waste from solution residues is carried out in a countercurrent pulsation column, and leaching, sorption and extraction are carried out in a closed cycle.

EFFECT: method provides high degree extraction of metals from ore with the possibility of joint processing of ores of different origin (sulfide and oxidized) in any ratio with the associated extraction of precious metals.

1 cl, 2 dwg, 2 tbl

Description

FIELD OF TECHNOLOGY

The present invention relates to a new, environmentally and economically more favorable method for the extraction of non-ferrous and precious metals from ores, in particular from sulfide and oxidized copper ores, in comparison with the methods of sulfuric acid, nitric acid or chloride leaching. The invention relates to an improved method and instrumental scheme for the extraction of non-ferrous metals from ores at hydrometallurgical enterprises, in particular to a technique for the extraction of non-ferrous and noble metals and the production of high-purity non-ferrous metals in metallic form and precious metals in the form of chemically pure compounds and / or alloys directly at the deposit where ores are mined and processed.

LEVEL OF TECHNOLOGY

From patent RU 2179589 C1 "Method for processing copper-containing products", publ. 02/20/2002, the invention is known, which relates to methods of processing oxidized copper ores, mixed sulfide-oxidized copper ores, as well as intermediate products, tailings and slags containing oxidized copper compounds. The method includes crushing and grinding the initial product to a size of fractions that exceeds the required size of fractions for flotation, leaching followed by separation of the liquid and solid phases of the product with simultaneous washing with a part of the extraction raffinate and water, after which the solid phase of the product is re-ground and flotation is carried out, and the liquid phase is subjected to extraction with the release of raffinate and copper-containing extractant solution, while the raffinate is repeatedly used in leaching and washing. In addition, it is possible to strip copper from the copper-containing solution of the extractant, and the regenerated extractant is used in the extraction, and the pure copper-containing solution is subjected to electro-extraction, after which the spent electrolyte is used during strip extraction, while the extraction is performed by contacting the copper-containing solution with an organic extractant of the cation-exchange type; recovering copper and improving the environmental friendliness of the process.

From patent US 8871162 B2 "The process of extracting gold and copper from mixed oxide-sulfide copper ores", publ. On October 28, 2014, a method is known for recovering gold and copper from gold-bearing copper ores obtained from mixed oxide-sulfide copper ore bodies through a series of flotation stages. More specifically, the present invention relates to a method for recovering gold and copper in which gold-bearing ores obtained from mixed oxide-sulfide copper ore bodies and / or their copper flotation by-products are subjected to at least one flotation stage after the dewatering stage. In particular, the method extracts copper and gold from the oxidized zone of porphyry and other mixed ore deposits. Likewise, the present method allows for the recovery of copper and gold from tailings and sink concentrates that are no longer suitable for further processing in the conventional process.

In accordance with one embodiment, ores originating from mixed oxide-sulfide copper ore bodies containing gold are subjected to copper flotation using xanthate as a collector after crushing, screening and grinding to a certain size sufficient to recover the minerals. Copper flotation by-products from copper flotation are subjected to at least one flotation stage using a combination of xanthate and fatty acid after a dewatering stage to recover copper and gold. The pre-concentration process, applied prior to conventional leach procedures, reduces the amount of gold-rich copper concentrate that can be acid leached without compromising metal recovery in the acid leach stage.

In another embodiment, there is provided a method for recovering copper and gold, in which ores separated from mixed oxide-sulfide copper ore bodies undergo at least one flotation stage using a combination of xanthate and a fatty acid as collectors after crushing, screening, grinding to the appropriate size (200 mesh) and dehydration. Then the copper-gold concentrate is subjected to acid (sulfuric acid) leaching before separating the solid and liquid phases.

The disadvantages of the technologies known in the prior art are the applied conditions of crushing and opening of minerals, leading primarily to an increase in operating costs and equipment.

The claimed technology dispenses with additional expensive fine grinding. This greatly simplifies the hydrometallurgical processing scheme: the material of the declared size does not require the introduction of additional flotation reagents.

The closest in essence technologies (analogs) are the following.

From the international application WO2004059018A1 "Recovery of metals from sulfide materials", publ. 07/15/2004, it is known to leach gold using the "Intec Copper" technology, which uses a chloride system containing copper (II) chloride - CuCl2, and sodium chloride - NaCl of a certain concentration. The process is carried out at atmospheric pressure and a temperature of 80-85 ° C, in a contact system. The authors of the invention have established the possibility of extracting gold subject to a number of technological parameters. Intec has also developed the Intec Gold Process (IGP) chlorination leach process for processing refractory arsenopyrite concentrates (https://www.yumpu.com/es/document/read/14807336/el-proceso-de-oro- intec-igp-intec-ltd).

From the textbook (Kotlyar Yu.A., Meretukov M.A., Strizhko L.S. Metallurgy of noble metals: Textbook in 2 kn.-M .: MISIS, Publishing house "Ore and Metals", 2005. -Kn. 2.-392 p.) The process of leaching with halogen-containing solutions is known, which is a method for extracting gold and other metals, especially from arsenic-containing ores, concentrates and residues, developed in 1959 in Germany. According to this technology, it was established that it is possible to extract gold and other metals from arsenic-containing ores, concentrates and residues (tailings) using hydrochlorination, if certain technological parameters are maintained during the process.

DISCLOSURE OF THE INVENTION

The technical problem that is solved by the application of the claimed method for extracting copper from sulfide and mixed (sulfide and oxidized) ores with the associated extraction of noble metals is to improve the process of extracting non-ferrous and noble metals from ores at enterprises (to obtain increased extraction, associated extraction of noble metals), without unacceptable deterioration of results (increased costs, the emergence of hazardous waste, etc.); to increase the extraction of metals from ores to 96 - 98% and to ensure the possibility of joint processing of sulfide and oxidized ores in any of their ratios, with associated extraction of precious metals from ores.

The technical result consists in increasing the efficiency of extracting metals from ore, as well as the possibility of joint processing of ores of different genesis (sulfide and oxidized) in any ratio with the associated extraction of precious metals.

The claimed technology has the following advantages:

• The high concentration, permeability and activity of the halogen leach solution allow the process to be carried out in a closed cycle on high-coarse ore (630 microns). The leaching solution is recyclable, which makes it possible to minimize the consumption of reagents and increase the throughput of metals up to 96-98% due to the leaching process with high excess acidity. Leaching time is 30-90 minutes. The achieved effect: the ability to work on coarse grinding ore (no ball grinding), higher recovery (up to 98%), lower (tens of times) acid consumption, low operating costs (2 or more times), as an advantage, significantly lower capital costs for equipment and construction of buildings. On analogous methods, high concentrations of leaching agents are impossible due to the non-closed nature of the technological process and the need to neutralize them.

• Coarseness of the processed ore, namely, the absence of ball grinding (minus 630 plus 160 microns versus 74 microns and less for analogs) with high recovery. The inventive method dispenses with: expensive ball grinding, without thickening of products and their filtration, without building a tailing dump, the ore after extraction of useful metals from it does not contain significant tailings of metals, and can be used for the construction or reclamation of mined pits, laying underground workings, construction roads. An economic effect is achieved: due to the use of an instrumental circuit based on countercurrent pulsation columns, which makes it possible to abandon the flotation of sulfide ores and conduct direct leaching of the original sulfide and mixed ore by a hydrometallurgical method, eliminating expensive processing of grinding, flotation, thickening, filtration, significant water consumption and stacking tailings in the tailing dump. The use of ball grinding on analogous methods and technologies, which is necessary for the flotation of sulfide ores, makes it impossible to refuse thickening and filtration due to the low hydraulic size of the material, which does not allow obtaining a solution without suspensions in the absence of the indicated conversions.

• Obtaining a commercial pure solution of copper and associated metals without suspensions, which makes it possible to abandon sorption from pulps, and leads to a reduction in the sorption time from 10 hours to 30-15 minutes, and also allows to significantly reduce the volume of sorption equipment, eliminating abrasive wear of the sorbent and reducing its consumption. The absence of suspensions in the solution also allows the commercial solution to be sent for extraction without preliminary settling and filtration.

Thus, the distinctive features of the proposed method in comparison with analogues are:

• the use of coarse grinding ore minus 630 plus 160 microns, which makes it possible to simplify the ore preparation operation - by crushing, excluding its ball grinding to a size of minus 74 microns (required for flotation), the specific power consumption is reduced by 3 times;

• high concentrations of the leaching agent (halogen solution) and high excess acidity, high activity and permeability of the halogen leaching solution provide increased recovery of non-ferrous and precious metals from ore (up to 98%);

• no filtration process - significant savings in capital and operating costs;

• hardware design, due to which an increased rate of ongoing leaching processes is achieved, which leads to a significant reduction in equipment costs (decreases in its number), which leads to a decrease in the volume of buildings and structures and their cost, respectively;

• closed cycle: halogen solution, wash water, sorbents / extractants are in circulation, as a result, low specific consumption of reagents and heat is achieved;

• efficiency and environmental safety of the process due to the closed cycle, exclusion of the stage of neutralization, thickening and filtration of the pulp, decontamination of tailings and exclusion of the tailing dump, which contains reagents;

• Possibility to use ore after leaching (after washing with water) for various purposes, laying workings, for road construction, in open-pit mining, reclamation of open pits.

• production of a consumable reagent directly on site from generally available sodium chloride (from table salt);

• production of cathode metal directly at the mine;

• full automation of the process;

• joint processing of mixed ores containing both sulfide and oxidized mineralization at any ratio;

• the ability to profitably extract associated precious metals with low concentrations in the ore.

The claimed technical result is achieved due to the proposed improved method for the production of copper from sulfide and mixed (oxidized and sulfide) ores with associated extraction of noble metals, including crushing of ore, leaching of non-ferrous and noble metals with a solution, washing with water of solid leaching waste from solution residues, sorption, extraction , reextraction, electrolysis, characterized in that the leaching is carried out with a halogen solution at a size of minus 630 plus 160 microns.

In this leaching of non-ferrous and noble metals, a halogen solution containing copper (II) chloride 2-water - 200-300 g / l, sodium chloride - 150-300 g / l or a halogen solution containing copper (II) chloride anhydrous - 20 -100 g / l, sodium chloride - 100-200 g / l, iron (III) chloride 6-aqueous - 50-150 g / l.

In this case, the acidity of the halogen solution is maintained in the pH range of 1.0 - 1.9.

In this case, the leaching of non-ferrous and noble metals with a solution and the washing of solid leaching wastes from the residues of the solution is carried out in a counter-current pulsation column.

In this case, the process of leaching, sorption and extraction is carried out in a closed cycle.

The above and other objects, features, advantages, as well as the technical significance of the present invention will be better understood from the following detailed description of the invention with reference to the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a schematic process flow diagram, where 1 is a crushing complex; 2 - pulsating leaching column; 3 - pulsating washing column; 4 - apparatus for separating solution and water; 5 - sorption apparatus; 6 - desorption apparatus; 7 - apparatus for liquid extraction; 8 - reextraction apparatus; 9 - electrolyzer.

FIG. 2 shows a block diagram of a method for producing cathode copper from sulfide and mixed (sulfide and oxidized) ores with associated extraction of precious metals.

CARRYING OUT THE INVENTION

The method includes the following basic operations:

• Crushing of ore;

• Leaching with solution and washing with water in counter-flow pulsating columns;

• Sorption

• Extraction, re-extraction;

• Electrolysis.

Crushing of ore.

Ore crushing is carried out by a dry method with air classification to the required size (minus 630 plus 160 microns). Material of this size is coarsely ground. The degree of crushing depends on the size of the source material coming from the deposit. With an average feedstock size of 250,000 microns, the final degree of crushing is 630 microns, which is distributed between 4-5 stages. For crushing of the first stage, a jaw crusher is used, for the subsequent ones, cone crushers and / or roller crushers. The finished class is displayed after each stage of crushing by means of air classification.

Leaching.

For direct leaching of ores containing non-ferrous and noble metals in the technology proposed for patenting, a counter-current pulsation column and one of the halogen solutions proposed below are used:

Solution No. 1: copper (II) chloride 2-water - 200-300 g / l, sodium chloride - 150-300 g / l.

Solution No. 2: anhydrous copper (II) chloride - 20-100 g / l, sodium chloride - 100-200 g / l, iron (III) chloride 6-aqueous - 50-150 g / l.

The acidity of the solution is maintained in the pH range 1.0 - 1.9 (changes during the entire process). The redox potential of the transfer of metals into solution is well known, and is selected according to the initial composition of the ore. The activity of the solution allows you to close the leaching process into a cycle, repeatedly returning the solution to the head of the process.

Washing of solid leaching wastes from solution residues is carried out in the same way - in a pulsating column. The return of the wash water to the washing process is carried out through the process of separating the reagents dissolved in it.

Sorption.

Sorption is carried out in a closed cycle using pressure sorption columns. After electrolysis, the stripping solution is returned to the process. The eluate is returned to the leaching process. The parameters of the sorption process are determined in a generally known manner and do not need a detailed description.

Extraction.

Liquid extraction is also performed in a closed cycle; after electrolysis, the stripping solution is returned to the stripping process. The raffinate is returned to the leaching process. The extraction process is carried out in any of the existing types of equipment using existing extractants. The parameters of the extraction process are determined in a generally known manner and need not be described in detail.

Electrolysis.

Metal electrolysis is performed from stripping / desorption solutions.

The electrolysis process parameters are determined in a generally known manner and need not be described in detail.

Description of the basic technological scheme for the production of cathode copper from sulfide and mixed (sulfide and oxidized) ores with associated extraction of precious metals, shown in figure 1.

The technological process is carried out by the following sequence of steps:

1. The original ore undergoes dry multistage crushing with air classification in pos.1. Sludge with an output of no more than 10% is processed in a separate branch.

2. Ore of the required size class minus 630 plus 160 microns is fed for leaching with circulating solution in a counter-flow pulsating column (item 2).

3. The solution saturated with metal from the ore is sent to pos. 5, into the sorption apparatus.

4. The cake from the column (pos. 2) is sent for washing to pos. 3 and subsequent storage in a semi-dry state.

5. The solution diluted with water from the washing column (item 3) is sent to the apparatus for separating solution and water (item 4), the water from which is returned to the washing process (item 3), and the solution is combined with a saturated leaching solution and sent to item ... 5.

6. As a result of sorption (item 5), valuable components of the solution pass into the sorbent and are sent to the desorption process (item 6) to obtain a commercial solution supplied for electrolysis (item 9). The sorption eluate is sent to pos. 7 for liquid extraction.

7. Sorbent in the process of desorption pos. 6 is cleared of valuable components and returned to pos. 5 for sorption. The commercial solution is fed to pos. 9 for electrolysis.

8. As a result of liquid extraction (pos. 7) valuable components of the solution pass into the organic phase and are sent to the re-extraction process (pos. 8) to obtain a commercial solution supplied for electrolysis (pos. 9).

9. The organic phase in the process of re-extraction (pos. 8) is cleaned of valuable components and returns to pos. 7 for extraction. The commercial solution is fed to pos. 9 for electrolysis.

10. After electrolysis - electrolyte with high acidity is returned to the desorption process (item 6) and to the re-extraction process (item 8).

It should be noted that, if it is necessary to isolate both noble metals (using sorption) and non-ferrous metals, which are released during extraction, electrolysis (item 9) is performed separately for non-ferrous and separately for noble metals.

Comparison of the claimed technology with analogs is presented in table 1.

Table 1

Examples of technology implementation.

The studies were carried out on the ores of deposits, which by their nature have sulfide and oxide components in different proportions.

Almalyk deposit. The Republic of Uzbekistan.

The research was carried out on oxidized and sulphide ore, size minus 630 plus 160 microns and minus 160 microns. The leaching and washing process took 90 minutes. Solution No. 2 was used, the process temperature was 95 ° C.

Udokan deposit. RF, Trans-Baikal Territory.

The research was carried out on oxidized and sulphide ore, size minus 630 plus 160 microns. The leaching and washing process took 60 minutes. Solution No. 1 was used, the process temperature was 95 ° C.

The average research results are presented in table 2.

table 2

The non-obviousness of the solution lies in the combination of the use of high-size ore, a highly active and highly permeable halogen solution, a closed technological process, the absence of intermediate enrichment conversions, and the absence of filtration of the ore processing process (method). The exclusion of a significant part of the processes in accordance with the list above does not worsen the final result, but only reduces the costs of maintaining these redistributions. Attempts to eliminate the processes of filtration, flotation, ore crushing, chemical neutralization of reagents with similar methods will lead to the impossibility of work, or a significant deterioration in the final result.

Thus, in the invention with a minimum number of operations, the maximum technical result is achieved - a high extraction of metals from the ore, as well as the possibility of joint processing of ores of different genesis (sulfide and oxidized) in any ratio with the associated extraction of precious metals. As an advantage, a low cost of production of non-ferrous and noble metals and a low cost of capital investments are achieved, which makes it possible to ensure the economic and environmental friendliness of the method for the production of metallic copper with the associated extraction of non-ferrous and noble metals in comparison with existing analogues, directly at the deposit.

The environmental friendliness of the method consists in a significant reduction, both qualitatively and quantitatively, emissions of harmful and hazardous substances (into the atmosphere, hydrosphere) and waste, due to the closed nature of the technological process. Waste in the form of semi-dry cake is class V waste and is suitable for use in construction, which is confirmed in accordance with the "Criteria for classifying waste as IV hazard classes according to the degree of negative impact on the environment" (APPROVED by order of the Ministry of Natural Resources of Russia dated December 4, 2014 N 536) ...

Claims (1)

A method for extracting copper from sulfide and mixed oxidized and sulfide ores with associated extraction of precious metals, including crushing of ore, leaching of copper and precious metals with a solution, washing with water from solid leaching waste from solution residues, sorption, extraction, stripping, electrolysis, characterized in that crushing ores are carried out to a size class of -630 +160 microns, for leaching a solution is used containing, g / l: copper (II) chloride 2-aqueous - 200-300, sodium chloride - 150-300 or a solution containing, g / l: anhydrous copper (II) chloride - 20-100, sodium chloride - 100-200, iron (III) chloride 6-aqueous - 50-150, while the acidity of the solution is maintained in the pH range 1.0-1.9, and leaching and Washing of solid leaching wastes from the solution residues is carried out in a countercurrent pulsating column, and leaching, sorption and extraction are carried out in a closed cycle.

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