RU2585593C1 - Method for heap leaching of gold from refractory ores and technogenic mineral raw material - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to method of heap leaching of gold from starting material in form of gold-containing refractory ore and man-made mineral stock. Method involves agglomeration of initial raw material by adding to it of binding material, forming a pile, leaching of gold by supplying the solution of leaching reagent, recycling of working solutions, collection of productive solutions and extraction of gold. Primary leaching of free gold and gold in intergrowths is performed with solution of reagent-complexing agent, followed by maintenance and supplied to stack sulfuric-peroxide and carbonate-peroxide solutions, past photoelectrochemical treatment, followed by further exposure and additional leaching of fine and gold, opened during oxidation of magnetite, sulphide-sulphosalt minerals and transformation of structure of quartz-chalcedony.

EFFECT: higher efficiency of leaching of gold from starting material.

2 cl, 1 ex

Description

The invention relates to hydrometallurgy of non-ferrous and noble metals, namely to the extraction of gold from refractory ores and technogenic mineral raw materials, and is intended for the extraction of industrially valuable metals and the removal of migration-active elements toxic to biota from it.

A known method of leaching gold from ores, including crushing them, forming stacks from crushed ores, irrigating the stack with a solution of leaching reagents and collecting productive solutions (see Heap and underground metal leaching. M .: Nedra. 1982).

The disadvantage of this method is its low efficiency due to the low extraction of dispersed and fine gold, which makes up the bulk of the reserves of refractory ores and technogenic formations, due to the low permeability of ores for solutions and their insufficient access to intramineral inclusions of gold.

Closest to the claimed is a method of extracting dispersed gold from refractory ores and industrial mineral raw materials, including sintering the gold-containing mineral mass of the feedstock by adding a binder to it, forming a stack, leaching of gold by feeding a solution of gold leaching reagent to the stack, collecting working solutions, followed by the allocation of gold from them (see RF patent 2461637, IPC С22В 11/00, publ. September 20, 2012).

The effectiveness of this method is also not large enough due to the impossibility of extracting most of the dispersed gold contained in particles of magnetite, sulfide-sulfosalt (sulfosol) minerals, as well as quartz and chalcedony.

The technical result of the invention is to increase the efficiency of gold extraction from ores and man-made mineral formations by increasing the extraction of fine and dispersed gold contained in magnetite, sulfide-sulfosalt (sulfosol) minerals, as well as in particles of quartz and chalcedony.

The specified technical result is achieved by the fact that the method of extracting dispersed gold from refractory ores and man-made mineral raw materials, including sintering the gold-containing mineral mass of the feedstock by adding binder to it, forming a stack, leaching of gold by feeding a solution of a leaching reagent to the stack, recycling of working solutions, the collection of productive solutions with the subsequent separation of gold from them, characterized in that after the formation of the stack carry out primary leaching free gold and gold in the intergrowths with a complexing reagent solution, pause and feed into the stack sulfuric acid peroxide and carbonate peroxide solutions that have undergone photoelectrochemical treatment, hold the next pause, after which additional thinning of fine and dispersed gold exposed during the oxidation of magnetite is carried out, sulfide-sulfosalt minerals and the transformation of the structure of quartz-chalcedony, a solution of a complexing reagent with a repeat of the irrigation cycle to ec cally justified extraction level.

The method also differs in that the supply to the stack of sulfuric acid peroxide and carbonate peroxide solutions that have undergone photoelectrochemical treatment is carried out either simultaneously or sequentially, depending on the ratio of gold-containing minerals:

magnetite, quartz-chalcedony and sulfide-sulfosalt (sulphosol) minerals.

Distinctive features of the proposed method is that after agglomeration, the agglomerated ore is stacked and the primary leach of free gold and gold in intergrowths is carried out with a complexing reagent solution, and after recirculation of working solutions, collection of productive solutions, and the separation of gold from them, they pause and feed a stack of sulfuric acid-peroxide and carbonate-peroxide solutions that have undergone photoelectrochemical treatment, pause for a second time, after which and they perform additional leaching of dispersed and finely disseminated gold, discovered during the oxidation of magnetite, sulfide-sulfosalt minerals, transformation of the quartz-chalcedony structure, a solution of a complexing agent with a repeat of the irrigation cycle to an economically justified recovery level.

The method is as follows.

The initial gold-containing raw material (ore or man-made mineral mass) undergoes agglomeration (pelletizing) by adding to it a binder material, such as cement, water, and processing the resulting mixture in an agglomerator.

A stack is formed from the pelletized material and primary leaching of “free” gold and gold in the intergrowths is carried out by irrigation of the surface with a reagent-complexing agent solution from its surface and recycling of the working solutions until it reaches the gold content required by sorption conditions. After that, productive solutions are collected and gold is precipitated from them by precipitation or sorption. The stack is then not irrigated for several days. After pausing, two types of active oxidizing solutions are fed to the stack: sulfuric acid peroxide and carbonate peroxide.

, мононадугольной H₂CO₄ и надугольной Н₂С₂О₆ кислот. Активные соединения углерода совмещают свойства окислителей и комплесообразователей для железа, меди и других металлов в составе сульфидно-сульфосолевых минералов, а также способны переводить окись кремния в поликремниевые кислоты.Oxidizing solutions are prepared in a photoelectrochemical reactor. An active carbonate-peroxide solution is prepared by bubbling air with an initial solution of alkali metal carbonate or hydrogen carbonate, membraneless electrolysis with the formation of dissolved diatomic oxygen and carbon dioxide in it, released on the anode, and then irradiating the electrolysis solution with UV light in the range of 180-300 electromagnetic wavelengths nanometers by circulating the solution through submersible UV lamps or by irradiation with mounted (external) UV lamps, with continued electrolysis, mainly in the cm zone Shivani anolyte and catholyte to form eventually active oxygen, under which commonly understood various allotropic forms proper oxygen and its compounds with hydrogen (ozone, hydrogen peroxide, hydro-xylo-radical) and ion $$C_2{O}_{\mathrm{four}}^{+}$$

mono-angular H ₂ CO ₄ and sub-angular H ₂ C ₂ O ₆ acids. Active carbon compounds combine the properties of oxidizing agents and komplesoobrazovateli for iron, copper and other metals in the composition of sulfide-sulfosalt minerals, and are also able to convert silicon oxide to polysilicic acid.

Sulfuric acid peroxide solution is prepared in a similar manner in a photoelectrochemical reactor from a basic aqueous solution of sulfuric acid. In this case, the specific (from one mole of sulfuric acid) yield of reactive oxygen species (ROS) will be higher, since only molecular diatomic oxygen and water vapor will be released on the anode, and hydrogen peroxide will be formed not only by irradiating electrolytic oxygen and UV vapor rays, but also through the formation on the anode of a metastable mononadseric acid. The obtained carbonate-peroxide solution containing reactive oxygen species and its compounds with hydrogen and carbon, and the sulfuric acid-peroxide solution are jointly used for the oxidation and structural transformation of mineral matrices containing finely disseminated and / or dispersed gold in the composition of ores or technogenic mineral mass. In this case, intense oxidation and leaching of iron and copper by hydrogen carbonates and sulfates, oxidation of sulfur by reactive oxygen species (ROS), with the formation of additional sulfates, a local conversion of silicon oxide to metasilicic acid with its subsequent polymerization, active compounds of carbon with oxygen and hydrogen, which provides on the whole, the preparation of the mineral matrix for the subsequent leaching of the fine and dispersed gold included in it.

Arsenic and antimony, which are dissolved in the components of the sulfuric acid peroxide solution, as part of arsenopyrite, stibnite, sulfosalt (sulfosol) minerals, are extracted from productive solutions by ion-exchange sorbents, which subsequently significantly reduces environmental pollution as a result of migration with rainwater from spent KB stacks. Mixing 2 types of solutions in a stack material (in a certain ratio) allows one to form a metastable reactive medium in it with the presence of carbon dioxide, sulfate anion, and ROS that are aggressive towards sulfide-sulfosalt minerals.

Metastable active carbonate complexes and hydroxylions provide a complex effect on the matrix of gold-containing mineral particles of quartz and chalcedony. In the event that sulfides and / or sulfosalts prevail in the gold-bearing mineral mass, then sulfuric acid peroxide solution is first fed to the stack, and then carbonate-peroxide solution, with the predominance of productive quartz-chalcedony paragenesis, carbonate-peroxide is first fed to the stack, and then sulfuric acid peroxide solution. With a close value of the content in the mineral mass of these groups of gold-bearing minerals, the sulfuric acid peroxide solution and the carbonate peroxide solution are fed to the stack simultaneously or as a mixture. After supplying the active solutions to the stack, a pause is maintained for a duration of several days to several tens of days.

The processing of the stack material with leached “free” gold and gold in splices and oxidized and structurally prepared mineral matrices with finely disseminated and dispersed gold at the final stage is carried out with a solution with a complexing agent for gold.

An example of a specific use of the method.

The method was tested on the stale tailings of the Talatuysky ore ore deposits of the Darasunsky ore field, in which there is gold in aggregates and not recovered in concentrate contained in mineral particles of magnetite, chalcopyrite, arsenopyrite, quartz, chalcedony, “fine” and dispersed gold. Moreover, dispersed gold is not extracted from refractory ores and tailings by heap leaching using a simple “oxygenated” cyanide solution, but only with active solutions.

An active carbonate-alkaline solution was prepared from a 2% soda solution in a photoelectrochemical reactor by bubbling with air to saturate with oxygen for 1 hour, electrolysis for 1 hour and irradiation with UV light in the range of 180-300 nanometers with DRT-230 lamps for 10 min with ongoing electrolysis. An active sulfuric acid-peroxide solution was prepared from a 0.3% sulfuric acid solution in a photoelectrochemical reactor by bubbling with air to saturate with oxygen for 1 hour, electrolysis for 1 hour, then injected to a concentration of 0.1% hydrogen peroxide and irradiated with UV light in the range 180- 300 nanometers with DRT-230 lamps for 20 minutes

The tails were mixed with water (7.5% by weight), cement 5 kg / t and lime 0.3 kg / t and agglomerated (pelletized) in an agglomerator. After pelletizing, the pellet-shaped mineral mass was stacked and kept for 3 days to solidify the pellets and a working solution was supplied at a rate of 500 g of cyanide / t solid as the main leaching reagent and conditioning alkali, added until the solution reached pH 10. The resulting productive solution was fed in sorption columns loaded with coal. The mother liquor was supplemented with cyanide, the pH was adjusted with alkali and fed to a stack. The cycles continued until the gold content in the productive solution fell below 0.3 mg / L. After a 5-day pause, a sulfuric acid-peroxide solution obtained in a photoelectrochemical reactor was fed into the stack before it started to drain through the drainage.

Then a pause of 10 days was held and a carbonate-peroxide solution, also obtained in a photoelectrochemical reactor, was fed into a stack. After another 3 days of aging in a stack of a combined solution with a pH of 9.5, water was fed into the stack. The resulting solution was passed through sorption columns with ion exchangers selectively sorbing arsenic, antimony and heavy metals, including copper. After washing the stack, a solution of sodium cyanide with a concentration of 0.08%, prepared on the basis of water, was fed into it. Working solutions of the first leaching stage with a gold concentration of more than 20 mg / L were collected in a drainage ditch and fed to sorption columns of the 1st stage of sorption, in which ion-exchange resins prepared in an active alkali-reinforced solution were placed, sorbing complex anions of iron, copper, silver and gold. The gold content of the resin was 7 mg / g.

After the solution of the first leaching stage was discharged, a concentrated (2%) sodium cyanide solution was again freshly prepared on the basis of the active soda solution and was added to the stack at the rate of T: W = 10: 1, which was kept in the stack for two days, after which dehydrated solutions of the first stage. At the same time, such anhydrous solutions with impurities extracted from them were strengthened with cyanide and saturated with atmospheric oxygen before being fed for re-irrigation. Working solutions of the second stage, after releasing them from the stack, were sent to coal sorption columns. The concentration of gold on coal was 5 mg / g. Next, the resin and coal were sent for desorption. Anhydrous solutions were further fortified with cyanide to a concentration of 300 mg / L, oxygenated with air and pumped into a stack to control gold recovery. The cycles of the second leaching stage were continued until a critical concentration of gold in solution of 0.1 mg / L was reached.

Claims (2)

1. The method of extracting dispersed gold from the feedstock in the form of gold-bearing refractory ores and man-made mineral feedstock, including sintering the feedstock by adding a binder to it, forming a stack, leaching gold by feeding a solution of a leaching reagent to the stack, recycling working solutions, collecting productive solutions with the subsequent separation of gold from them, characterized in that after the formation of the stack, primary leaching of free gold and gold in intergrowths of p with a solution of a complexing reagent, hold and feed sulfuric acid-peroxide and carbonate-peroxide solutions into the stack, which underwent photoelectrochemical processing, then hold, after which additional thinning of fine and dispersed gold revealed during the oxidation of magnetite, sulfide-sulfosalt minerals and structural transformation is carried out quartz-chalcedony. 2. The method according to p. 1, characterized in that the supply to the stack of sulfuric acid-peroxide and carbonate-peroxide solutions that have undergone photoelectrochemical treatment is carried out simultaneously or sequentially, depending on the ratio of gold-containing minerals in the form of magnetite, quartz-chalcedony and sulfide-sulfosalt minerals.