RU2571676C1 - Processing method of polymetallic ores - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: ore granulation is performed by sulphuric acid solution at flow rate 0.033-0.2 t/t of ore. Liquid glass with consumption 0.0-2.0% is used as binding addition. The liquid glass consumption depends on content of the clay minerals in ore. The sulphuric acid flow rate is selected depending on the ore acidity. Composition of the initial material can determine the necessity of additions - oxidants and additional binders. The stage of holding is performed, during it excessive moisture is removed, and granules obtain strength. The held granules are stockpiled and leached with water or subacid solution of sulphuric acid.

EFFECT: increased extraction of valuable components to the productive solution, reduced consumption of the leaching solution, reduced time of pile treatment, reduced volumes of production solutions, and hence volumes of discharge solutions; prevention of pile colmatation.

5 cl, 1 dwg, 2 tbl, 3 ex

Description

The invention relates to hydrometallurgical methods for processing clay polymetallic raw materials and can be used in the processing of clay and prone to crushing of uranium ores by heap leaching.

A known method of processing uranium ores, including heap and underground leaching of ore with a solution of sulfuric and sulfurous acids (Method for the extraction of uranium from ores. Pat. 2234550, Russian Federation, IPC ⁷ C22B 60/02, C22B 3/06).

The disadvantages of the method include the risk of failure of the heap due to mudding (or siltation) during the processing of clay uranium ores.

The closest is a method of processing uranium ores, including crushing them to a size class of -20 mm and heap leaching of the resulting material. (Method for opening uranium ores. Pat. 2154121, Russian Federation, IPC ⁷ C22B 60/02, C22B 3/08).

The disadvantages of the method include the high consumption of leaching solution, the time spent on stacking (several months), the risk of failure of the heap due to clogging (or siltation) - the formation of water-resistant layers consisting of ore fines and products of the destruction of the bearing rock (such as gypsum and silicic acids). The high content of clay minerals makes the processing of some ores by the KB method generally impossible, precisely because of the mudding.

The technical result of the proposed method for processing clay polymetallic raw materials is the following:

- increase the extraction of valuable components in a productive solution;

- reduction in leach solution consumption;

- reduction of the time spent on the stack;

- a decrease in the volume of productive solutions and, as a consequence, the volume of waste solutions;

- prevention of hematitis.

The technical result is achieved by the fact that in the process of preparing crushed clay raw materials by granulation with a solution of sulfuric acid, durable water- and acid-resistant, but permeable aggregates are formed - granules. Granulation is carried out with a solution of sulfuric acid with a flow rate of 0.033-0.2 t / t ore. As a binder, liquid glass is used with a flow rate of 0.0-2.0%. The granules obtained are stacked in heaps, aged, and then heaps are leached by irrigation with water or a slightly acidic solution of sulfuric acid.

The consumption of sulfuric acid depends on the acid intensity of the ore material.

In the case of a low content of clay minerals (less than 20%), binders (bentonite, cement) are additionally added to obtain strong granules.

Additionally, an oxidizing agent, hydrogen peroxide, can be introduced for granulation.

The formation of granules occurs due to the destruction of clay minerals and the formation of silicic acids:

Silicic acids formed bind ore fines into granules. At the stage of pellet aging, silicic acids lose moisture with the formation of a silica gel skeleton, which provides the granule with water and acid resistance. As a result, with heap leaching, material does not clog.

When sulfuric acid interacts with liquid glass, silicic acid is formed:

When hydrogen peroxide is introduced as an oxidizing agent, the extraction of uranium, rhenium, copper, cadmium, cobalt and nickel increases. The introduction of hydrogen peroxide allows you to achieve the following:

- increases the degree of extraction of uranium from minerals in which it is represented in the oxidation state +4, such as uranofan and brannerite.

- the degree of extraction of rhenium, copper, cadmium increases due to the transition of their insoluble sulfides to a soluble state, i.e. soluble sulfates are formed;

- the degree of extraction of cobalt and nickel increases due to the reaction of the interaction of arsenates (smaltin and kupffernickel) with sulfuric acid and the formation of soluble sulfates, while extremely toxic arsine (H ₃ As) is not released into the atmosphere, and the reaction proceeds by the following mechanism:

Example 1

The studies were carried out on uranium ore, the main minerals of which are quartz, clay minerals (20%) and feldspars. Among the uranium minerals in the ore are nasturan, uranium mobiles, arsenates, uranium phosphates and uranium mica. The uranium content in the test ore is 0.085%.

Uranium ore was ground to a particle size of -10 mm and granulated with sulfuric acid at a flow rate of the last 0.033 t / t of ore and 2% water glass, after which the obtained granules were subjected to heap leaching with a 5% sulfuric acid solution. During leaching, the granules did not collapse; no colmatation occurred.

The leaching results are presented in table 1.

Good leaching rates of granular material compared to the initial ore are due to the fact that the granulation of the ore is carried out with concentrated sulfuric acid with liquid glass, and soluble uranyl sulfate is formed in the granules, which leaches perfectly when treated with acidified water. When leaching the bulk material, the process of diffusion of sulfuric acid to the uranium mineral must first go through, and only after this is the reaction of formation of soluble uranyl sulfate and its leaching. Therefore, KB of granular material leads to an increase in uranium recovery by 9.4%, a decrease in the volume of productive solutions by a factor of ~ 2, and a decrease in the time cycle of 2.7 times.

Example 2

The studies were carried out on uranium ore, which is granites with mineralization superimposed on them, consisting of uranium minerals, zeolites, clay minerals (23%) and quartz. Among the uranium minerals in the ore are represented by beta-uranotyl, uranofan, otenite, and meta-tenit. As a result of radiometric ore sorting, a fraction with a uranium content of 0.39% was isolated.

Rich clay uranium ore was ground to a grain size of -10 mm and granulated with sulfuric acid at a flow rate of 0.05 t / t ore and 2% water glass, after which the obtained granules were subjected to heap leaching with a 5% sulfuric acid solution. During leaching, the granules did not collapse; no colmatation occurred.

As a result of granulation of rich uranium ore, uranium recovery is increased by 59.7%, the volume of productive solutions decreases by a factor of 3.5 and the time cycle is reduced by a factor of 9.

Example 3

The studies were carried out on uranium-rare metal ores, which are represented by three main components: fish bone detritus, iron sulfides and clays (42%). The most important of these is bone detritus, in which uranium (0.041%) and rare earth elements (0.14%) are concentrated. Uranium is represented by oxides and phosphates.

Due to the high clay content, direct heap leaching of such ore is impossible, while propaganda is not profitable. Therefore, a special ore preparation is required for KB ore, which included disintegration of the material (up to -10 mm) for mixing with acid, granulation of ore with sulfuric acid without liquid glass, temporary exposure of granules (maturation) until the leaching solution is supplied. The presence of sulfides in the ore, with which rhenium, cobalt (0.13%) and nickel (0.24%) are associated, determines the need for their oxidation. Hydrogen peroxide was used as an oxidizing agent.

The results of ore leaching are presented in Figure 1. Nickel and cobalt are extracted immediately, at the stage of acidification of the column, at low pH values of BP. Uranium is leached in 2 stages - first the oxide form, then with an increase in acidity - phosphate. REMs are recovered last at high acidity BP. Since the processing of this type of ore by other methods is impractical, a comparison with them is not given.

Claims (5)

1. A method of processing polymetallic ores, including crushing ore and heap leaching, characterized in that prior to leaching, the ore is preliminarily granulated with a solution of sulfuric acid with a flow rate of 0.033-0.2 t / t ore using liquid glass as a binder additive with a flow rate of up to 2 , 0%, the obtained granules are stacked in heaps and granules are discarded, after which heaps are leached by irrigation with water or a slightly acidic solution of sulfuric acid. 2. The method according to p. 1, characterized in that the consumption of sulfuric acid is selected depending on the acid intensity of the ore. 3. The method according to p. 1, characterized in that the flow rate of liquid glass is selected depending on the content of clay minerals in the ore. 4. The method according to p. 1, characterized in that in addition to the granulation is introduced an oxidizing agent - hydrogen peroxide. 5. The method according to p. 1, characterized in that when processing ore with a low content of clay minerals, binders are additionally introduced - bentonite, cement.