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

Abstract

The invention relates to a method for processing laterite ore comprising nickel by means of microwave reduction roasting-hematite deposit transformation, which is characterized in that the method comprises the following steps: (1) a carbonaceous reducing agent is added into the laterite ore, and heated for 5min to 20min under microwave radiation after even blending so as to obtain laterite ore calcine; and (2) the laterite ore calcine is leached in a high-pressure container. The concentration of ore slurry leached is 10 percent to 30 percent, and the ore slurry is fed into oxygen-enriched air or pure oxygen to carry out oxidation leaching reaction. Nickel cobalt in the laterite ore enters the leached liquid, with iron transformed to hematite deposit. The method consumes less acid, with the leaching temperature greatly lower than that of the existing high-pressure acid leaching method, thereby being favorable to the decrease in manufacturing cost of leaching equipment; simultaneously, the scale in equipment is greatly decreased, the content of sulfate radical in the leaching residue is accordingly lowered, thus being favorable to the comprehensive utilization of the leaching residue.

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-hematite 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, for 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, which are highly dispersed and cannot be enriched by direct beneficiation. Only direct chemi...

AI Technical Summary

Problems solved by technology

[0012] 1. When the temperature is in the range of 250-270°C, the pressure is as high as 3.9-5.4MPa, which puts forward high requirements on the sealing of equipment such as the sealing of mechanical stirring shaft sleeves; considering the problem of anti-corrosion, it is necessary to use an autoclave lined with titanium, so the whole set Huge investment in system equipment and harsh operating conditions

[0013] 2. When leaching in the temperature range of 250-270°C, not only the stability of ferric sulfate decreases, but also the stability of aluminum sulfate decreases

The leaching residue contains relatively high sulfate radicals (often above 10-15%), is thermodynamically unstable, and the current technical conditions cannot be processed in large quantities, so long-term storage will cause harm to the environment

[0015] 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 leaching residue are currently difficult to solve