RU2413018C1 - Procedure for extracting valuable metals out of ore - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: procedure consists in saturating pulp prepared from ore with oxygen and in introducing leaching reagents and sorbents. Further, there are performed sorption leaching with saturation of sorbent with metal impurities and partially with valuable metals, in counter-flow sorption of base part of valuable metals and in withdrawing sorbents saturated with valuable metals. Also, before introduction of leaching reagents activating solution, treated with light radiation in ultraviolet region of spectre or photo-electro-chemically treated, is introduced into pulp prepared out of ore containing valuable metals in dispersed form. Sorption leaching is carried out in electric field for electro-sorption extraction of primarily leached metals with periodic withdrawal of sorbent from zone of electro-sorbtion.

EFFECT: reduced losses of industrially valuable metals.

3 cl

Description

The invention relates to hydrometallurgy of non-ferrous, noble and radioactive metals and can be used in the extraction of metals from ores, for example gold-bearing, with both industrial and non-industrial metal content.

A known method of extracting non-ferrous metals from solutions and pulps, in which to reduce the number of sorption steps and reduce the sorbent flow during continuous stepwise-countercurrent sorption on ion exchange resin, the ion exchange resin is additionally treated with an alkaline reagent at intermediate stages of sorption (see ed. Certificate of the USSR No. 933766, IPC 3 С22В 3/00, publ. 06/07/1982).

There is also known a method of extracting gold from ores containing natural sorbents, in which, to reduce the loss of gold with sorption leaching tailings, the product of gravity-flotation concentration is subjected to sorption leaching, with sorption leaching of the intermediate product in the first stage, and flotation concentrate and tailings of the first stage in the second stage, while the sorbent of the second stage is saturated at the first stage (see RF patent No. 2094503, IPC 6 C22B 11/00, publ. 10/27/1997).

The disadvantage of these methods is their low efficiency if in the processed pulp there are impurities of elements that reduce the capacity of the used sorbents for base metals.

The closest in technical essence and the achieved result is a method of sorption leaching of metals with reduced reagent treatment, including the introduction of pulp containing metals and impurity elements into the first of the sequentially installed packs, saturation of the pulp with oxygen, introduction of leaching reagents and sorbents into the pulp, metal leaching , their countercurrent sorption and removal of sorbents saturated with leached metals. Moreover, the introduction of leaching reagents is carried out after saturation of the pulp with oxygen in the next in the direction of the pulp movement of the pack, into which or in the next pack is introduced a sorbent for direct-flow sorption of dissolved impurities and part of the leached metals. After that, the output of these sorbents from the last patchouk direct-flow sorption. Countercurrent sorption of leached metals is carried out with the movement of the sorbent from the last in the direction of movement of the Pachuca pulp, and the output of sorbents saturated with leached metals is carried out from the last Pachuca of direct-flow sorption or from the next Pachuca following the movement of the pulp.

As the sorbent for direct-flow and counter-current sorption using ion-exchange resin or coal.

If gold and silver are jointly present in the solution, in order to reduce the loss of silver during sorption in the mode of maximum saturation of the resin with gold, it is proposed in this method to carry out sorption in two stages, gold is sorbed in the first stage, silver is sorbed in the second stage (see RF patent No. 2268316 IPC С22В 11/00, published on January 20, 2006).

The disadvantage of this method is its low efficiency in the case of the presence in the processed pulp of mineral particles containing dispersed gold or other noble metals and impurities of elements that reduce the capacity of the used sorbents for base metals, since in these cases the noble metals enter the liquid phase and sorbent in stages . Thus, the metal forms leached in the first tens of minutes from the surface areas of the mineral particles can be reprecipitated into clay and mica minerals, and the impurity elements, being absorbed by sorbents, create difficulties for the sorption of dispersed forms of noble metals passing into the liquid phase of the pulp at the final stage of the process.

The problem to which this invention is directed, is to increase the efficiency of extraction of precious metals from ores.

The technical result that can be obtained by implementing this invention is to reduce the loss of industrially valuable metals, including those in particulate form in the mineral matrix of solid pulp particles.

The specified technical result is achieved by the fact that in the method for extracting precious metals from ores, including saturating pulp prepared from ore with oxygen, introducing leaching reagents and sorbents, sorption leaching with saturating the sorbent with metals with impurities and partially noble metals, countercurrent sorption of the main part of the noble metals and removing saturated noble metals of sorbents, according to the invention, into a pulp prepared from ore containing precious metals in a dispersion In the first form, before the leaching reagents are introduced, an activating solution is introduced that has been subjected to light irradiation in the ultraviolet region of the spectrum or photoelectrochemical treatment, sorption leaching is carried out in an electric field for electrosorption extraction of primarily leached metals with periodic withdrawal of the sorbent from the electrosorption zone. In addition, the activating solution is preliminarily saturated with oxygen, and the sorbents are subjected to preparation by treatment in an activating solution that has undergone irradiation with light in the ultraviolet region of the spectrum and / or photoelectrochemical treatment.

Distinctive features of the proposed method are: in the pulp prepared from ore containing noble metals in dispersed form, before entering the leaching reagents, an activating solution is introduced, which has been subjected to light irradiation in the ultraviolet region of the spectrum or photoelectrochemical processing, sorption leaching is carried out in an electric field for electrosorption extraction primarily leached metals with periodic withdrawal of the sorbent from the electrosorption zone, in addition, an activating solution redvaritelno saturated with oxygen, and the sorbents are subjected to a preparation treatment activating solution held light irradiation in the ultraviolet region of the spectrum and / or photoelectrochemical processing.

As an activating solution that has undergone light treatment in the ultraviolet region of the spectrum or photoelectrochemical treatment, solutions of alkali metals, in particular sodium chloride and oxygenated sodium hydroxide, can be used as an sorbent ion-exchange resin or coal.

Irradiating the activating solution with light in the ultraviolet region of the spectrum and photoelectrochemical treatment make it possible to produce ion-radical clusters in it, which transmit excitation to ions in the double electric layer and excitation of parts of the crystal lattice with dispersed gold through its active centers. Accordingly, the diffusion of gold atoms in the solid phase to the surfaces of microcracks and pores and its ions from film water to the bulk of the liquid phase of the pulp is enhanced.

Photoelectrochemical treatment involves the use of ultraviolet radiation in the electrode areas with the production of atomic oxygen, ozone, hydroxyl radical and other active compounds of oxygen and hydrogen, or irradiation of electrolytically treated solutions: anolyte, catholyte, and mixtures thereof.

The electrosorption sorption of primary leached metals with periodic withdrawal of the sorbent from the electrosorption zone allows, due to the intensification of dissociation of complex gold ions, its cations periodically diffusing toward the cathode. Consequently, in the cathode zones, the gold concentration increases, and the sorption process is intensified accordingly.

The preparation of the sorbent in an activating solution makes it possible to concentrate active ion radical complexes in their film phase and upper layers of the gel phase, which intensify the process of dissolution of dispersed gold.

Thus, this set of features contains features, each of which is necessary to achieve the claimed technical result in all cases of using the invention.

The method is as follows.

The initial mixed ore of the Kokpatas deposit, after being mined and transported to the processing site, is crushed and ground to yield a grade of 74 μm of 70%. The resulting pulp is concentrated to W: T = 1.1: 1 and fed to the first of 12 sequentially installed packs, where the pulp is saturated with atmospheric oxygen. From the first patchuka pulp is fed into the second and then into the third, in which they continue to saturate the pulp with atmospheric oxygen and at the same time through the pipeline they supply an alkali activating solution (for example, 10% NaOH) saturated with oxygen and subjected to photoelectrochemical treatment in a special reactor, which is a container with corrosion-resistant electrodes and a UV lamp mounted above them, acting on the anode space of the electrolytic cell. During the photoelectrochemical treatment of an oxygen-saturated solution, ion-radical complexes are produced that, upon subsequent mixing with the pulp, activate diffusion processes in the double electric layer, form additional active centers and excite clusters and dispersed gold atoms in the crystal lattices of carrier minerals. The same solution is used to prepare the sorbent - bifunctional anion exchange resin A-100 by adding to it a 2% solution of sodium cyanide, processing it with resin and subsequent separation on sieves. The sorbent simultaneously with cyanide solutions is fed into the 4th patch from the condition that the final concentration of cyanide reaches 0.3%, and then, together with the pulp, it is pumped into the 5th and 6th packs. These packs are equipped with a system of submersible tubular electrodes placed in the space between the jacket and the airlift conveying pipe, to which a voltage of 5-8 V is applied, which provides electrodiffusion of gold to the cathode space and, accordingly, a local increase in its concentration and intensification of sorption by an ion exchanger acting as a movable membrane. This is accompanied by intensive leaching of gold and at the same time its sorption, eliminating the reprecipitation of dissolved gold on sorbent minerals (clay miner als and carbon inclusions). The extraction of gold into the resin at the exit of the pulp from the 6th patchoux is 65% compared with 32% achieved in 3 hours of preliminary cyanidation using traditional technology. Further leaching of the pulp is carried out by a second portion of resin moving against the direction of movement of the pulp. At the same time, an additional recovery of another 23% of gold is achieved. Thus, the total recovery is 88% (by traditional technology -71%).

Claims (3)

1. A method of extracting precious metals from ores, including saturating pulp prepared from ore with oxygen, introducing leaching reagents and sorbents, sorption leaching with saturation of the sorbent with metals and partially noble metals, countercurrent sorption of the bulk of the noble metals and removing sorbents saturated with noble metals, characterized in that in the pulp prepared from ore containing precious metals in dispersed form, activating p is introduced before the introduction of leaching reagents target, the last treatment by light irradiation in the ultraviolet or photoelectrochemical processing absorption leaching is carried out in an electric field for extracting primary Electrosorption leached metals peck electrosorption of sorbent zones. 2. The method according to claim 1, characterized in that the activating solution is pre-saturated with oxygen. 3. The method according to claim 1, characterized in that the sorbents are subjected to treatment by treatment in an activating solution that has undergone irradiation with light in the ultraviolet region of the spectrum, and / or photoelectrochemical treatment.