Method for treating nickel-containing laterite by microwave reducing roasting-goethite precipitation conversion method

Abstract

The invention relates to a method for processing laterite comprising nickel by means of microwave reduction roasting-goethite deposit transformation, which is characterized in that the method comprises the following steps: (1) a carbonaceous reducing agent is added into the laterite, and heated for 5min to 20min under microwave radiation after even blending so as to obtain laterite calcine; and (2) the laterite calcine is blended into slurry and leached, the concentration of the mine slurry is 10wt percent to 30wt percent, the leaching temperature is 80 DEG C to 120 DEG C, the duration for leaching is 2h to 5h, and nickel cobalt in the laterite enters the leached liquid, with iron transformed to goethite deposit. The method consumes less acid which is equal to that of the high-pressure acid leaching method, but the operation temperature and pressure at the leaching stage are greatly lowered by reduction roasting, which is favorable to the decrease in manufacturing cost of leaching equipment.

Description

technical field [0001] The invention belongs to the technical field of mineral extraction and metallurgy. Specifically, the invention relates to a method for treating nickel-containing laterite ore by a microwave reduction roasting-goethite precipitation transformation method. Background technique [0002] Nickel is a versatile metal, often used in the production of stainless steel, superalloys, electroplating, catalysts and magnets. [0003] Although nickel exists in many kinds of minerals, there are currently two kinds of mineral raw materials for large-scale smelting and extraction of nickel, sulfide ore and oxide ore. Sulphide ore can generally be obtained by beneficiation of nickel concentrate. However, nickel-containing oxide ores such as laterite ores, due to the different origins of the minerals, nickel and cobalt exist in the minerals in the form of lattice replacement, are highly dispersed, and cannot be enriched by direct beneficiation methods, only direct chemic...

AI Technical Summary

Problems solved by technology

There are still two serious problems in the production of the high-pressure acid leaching process: one is that the aluminum dissolved during the leaching process is partially hydrolyzed at high temperature to form alunite / aluminite and other precipitates, which are deposited on the inner wall of the container, resulting in serious scaling of the equipment, which often has to be Stop production for equipment cleaning; Second, the iron part of the leaching slag exists in the form of jarosite, which contains a large amount of sulfate radicals. The leaching slag in the form of jarosite is thermodynamically unstable, and the current technical conditions cannot be processed in large quantities, so long-term stockpiling harmful to the environment

When the Caron method is used for treatment, iron will generate hydroxide precipitates when leaching under alkaline conditions, and the adsorption loss of nickel, especially cobalt, is large, so the recovery rate of nickel and cobalt is low, nickel is about 70-85%, and cobalt generally does not exceed 60%. %

[0010] In summary, there are still great difficulties in the treatment of nickel-containing laterite ore by wet process: the equipment for leaching with sulfuric acid at atmospheric pressure is simple, but the consumption of acid and alkali reagents is large; the energy consumption of the Caron process is relatively high, and the recovery rate of nickel and cobalt is low; Acid leaching can achieve a high leaching rate of nickel and cobalt under the condition of effectively reducing acid consumption. The technology is advanced, but the equipment is complicated and the investment is huge. At the same time, the scaling problem of equipment in production and the treatment of jarosite slag in leaching residue are currently Difficult to solve