RU2430172C1 - Extraction method of nickel from oxidised nickel ores - Google Patents

Abstract

FIELD: metallurgy. ^ SUBSTANCE: method involves heap leaching of nickel with sulphuric acid solution, neutralisation of production solution, sorption of nickel on ionite from it, processing of strippant so that nickel is obtained, supply of raffinate solution for heap leaching of ore during its revolution and circulation. At that, some part of raffinate is subject to neutralisation with lime milk and its cleaning from impurities of iron, manganese and magnesium by directing in the form of neutralised pulp to waste heap for deposition of iron, manganese and magnesium on it with further mixing with the main volume of cycling solution of raffinate and final strengthening with sulphuric acid. Volume of some part of raffinate, which is subject to neutralisation and cleaning, as per the amount of iron, manganese and magnesium, corresponds to their transition to production solution during leaching of nickel from the ore during circulation of cycling solution. ^ EFFECT: simplifying the utilisation process of iron, manganese and magnesium and heap leaching process of nickel. ^ 1 dwg, 1 tbl

Description

The invention relates to metallurgy, and in particular to methods for the extraction of nickel from oxidized nickel ores of ferrous and magnesian types.

As a prototype, a method was selected for the extraction of nickel from Ni-Fe-Mg lateritic ores containing a large amount of magnesium (US patent No. 5571308), in which magnesian ores are processed by heap leaching with a solution of sulfuric acid, followed by neutralization of the productive solution and then sorption of nickel on selective ionite resin. A high nickel content desorbate is sent for further processing with the extraction of cathode nickel by electro-winding, and part of the raffinate is neutralized with milk of lime and purified from impurities of iron, manganese and magnesium by sending in the form of a neutralized pulp to a spent pile to deposit iron, manganese and magnesium, followed by mixing with the main volume of the raffinate working solution and the addition of sulfuric acid.

The disadvantages of this method are the problems of utilization of a magnesium-containing solution, the disposal of iron hydroxide sediment and the need to constantly stabilize the volume of the leach solution by adding water to compensate for the volume removed from the turnover of the solution of magnesium sulfate and iron hydroxide.

The tasks to which the claimed invention is directed are to simplify the utilization of iron, manganese and magnesium and the entire process of heap leaching of nickel.

This problem is solved in that in a method for extracting nickel from oxidized nickel ores, including heap leaching of nickel with a solution of sulfuric acid followed by neutralization of the productive solution and sorption of nickel on the ion exchange resin, processing of desorbate, neutralization of part of the raffinate and precipitation of iron, part of the raffinate is sent to the spent heap for deposition of iron, manganese and magnesium, and the volume of the portion of the raffinate to be neutralized and purified, according to the amount of iron, manganese and magnesium, should correspond to their transition into the productive solution when leaching nickel from ore during the circulation of the circulating solution.

The method was carried out as follows.

A productive solution after heap sulfuric acid leaching of magnesia or gland ore containing nickel, cobalt, iron, magnesium, manganese and related impurities is fed to the operation of selective sorption of nickel and cobalt on a chelate-type ion exchanger, for example, DOWEX M4195. Sorption on a chelate-type ion exchange resin makes it possible to selectively sorb nickel and purify it of magnesium, manganese, and partially iron. Desorbate, reduced in volume by a factor of ten relative to the initial productive solution and containing up to 60 g / l of nickel and 5-6 g / l of iron, after hydrolytic purification from iron, is fed to the processing of the solution to produce cathode nickel by electro-winding or conditional nickel sulfate .

The precipitate of iron hydroxide formed during the cleaning of the desorbate is sent to the spent heap for joint disposal in the spent space of the quarry during its reclamation.

Part of the raffinate is subjected to neutralization with milk of lime and its purification from impurities of iron, manganese and magnesium by sending in the form of a neutralized pulp to the spent heap to deposit iron, manganese and magnesium on it, followed by mixing with the main volume of the raffinate working solution and adding sulfuric acid. Hydroxides of iron, magnesium and manganese are deposited on the ore material of the spent heap and are jointly stored in the spent space of the quarry for the extraction of oxidized nickel ore and its reclamation.

Moreover, the volume of the portion of the raffinate subjected to neutralization and purification, according to the amount of iron, manganese, and magnesium, should correspond to their transition to the productive solution during leaching of nickel from the ore during the circulation of the circulating solution.

After precipitation of iron, manganese and magnesium hydroxides on the spent heap, the solution is mixed with the main volume of the solution, added with sulfuric acid and fed to the heap ore leaching (see drawing).

This allows you to stabilize the circulating leach solution according to the content of iron, magnesium and manganese without filtering and the organization of special landfills for burial of precipitation of hydroxides of iron, magnesium and manganese.

The stabilization of productive working solutions by impurity content when a portion of the raffinate is fed after neutralization to the spent ore material to exclude hydroxides from the filtering process and the possibility of their precipitation on the spent ore material is confirmed by percolation leaching experiments performed on averaged core samples taken from the field nickel ores "Kungurskoye".

The chemical composition of magnesia ore,%:

Ni = 0.84

Co = 0.025

Fe = 12.39

Mn = 0.36

Mg = 14.65

Cr = 0.24

Ca = 8.8

SiO ₂ = 31.4

Table 1 shows the content of elements in the productive working solutions of percolation leaching after sorption of nickel on DOWEX M4195 ion exchange resin during the circulation of the solution without precipitation of hydroxides on the heap spent material and upon neutralization of 50% of these solutions and feeding them to the spent material on the percolation column.

First column.

Leaching and circulation of the leaching solution exiting the first column was carried out without neutralizing and removing impurities.

Second column.

A solution of sulfuric acid in an amount of 10 liters with a concentration of sulfuric acid of 100 g / l was fed into the top of the second column on the surface of the ore at a speed of 5 liters per hour / m ² . Leaching was carried out for 15 days. The total transit time of the solution through the ore layer is 3 days. Nickel sorption from the productive solution was performed on DOWEX M4195 resin. The raffinate was neutralized with milk of lime and fed to the surface of the ore in a spent percolation column. Then, the neutralized raffinate coming out of the spent column was analyzed for impurities and added with sulfuric acid to 100 g / L. After this, the reinforced solution was again fed to the surface of the ore to leach nickel.

From the above example it is seen that the removal of impurities from the raffinate is possible without organizing the process of separation of liquid and solid phases by filtration. It is enough to ensure the supply of neutralized pulp with hydroxides to the surface of the ore in a spent percolation column. This ensures stabilization of the salt composition of the productive solution, which allows more efficient control of the sorption process of Nickel.

Table 1 Heap leaching method The composition of the circulating leach solutions, g / l Ni With Fe Mg Mn Leaching time, day Percolation leaching without neutralization of the circulating solution 1. 1st productive solution 0.1 0.05 3,1 5.2 0.3 3 2. Revolving solution -1 0.1 0.06 6.9 14.8 0.7 6 3. The circulating solution - 2 0.1 0.06 7.2 16.1 0.8 9 4. The working solution is 3 0.1 0,07 8.7 18.3 1,1 12 5. The circulating solution is 4 0.1 0.08 10.3 20.5 1.3 fifteen Percolation leaching with neutralization and supply of circulating solution to the spent percolation column. 1. 1st productive solution 0.1 0.05 3,1 5.2 0.3 3 2. The circulating solution is 1 0.1 0.05 2.9 5.2 0.2 6 3. The circulating solution - 2 0.1 0,03 2.7 4.9 0.3 9 4. The working solution is 3 0.1 0.04 2.2 5.3 0.4 12 5. The circulating solution is 4 0.1 0,03 1.7 5,0 0.2 fifteen

Claims (1)

A method for extracting nickel from oxidized nickel ores, including heap leaching of nickel with a sulfuric acid solution, neutralizing the productive solution, sorbing nickel on it with an ion exchanger, processing the desorbate to produce nickel, supplying a raffinate solution to heap leaching of ore during its circulation and circulation, characterized in that part of the raffinate is subjected to neutralization with milk of lime and its purification from impurities of iron, manganese and magnesium by sending in the form of a neutralized pulp to the spent heap for precipitation on iron, manganese and magnesium, followed by mixing with the main volume of the raffinate working solution and adding sulfuric acid, while the volume of the part of the raffinate to be neutralized and purified, according to the amount of iron, manganese and magnesium, corresponds to their transition to the productive solution when nickel is leached from ore when circulating a circulating solution.

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