Method for treating low-grade nickel laterite ore

Abstract

The invention relates to the field of wet metallurgy, in particular to a method for extracting nickel and cobalt by using wet processing from low-grade nickel laterite ore. Brown iron ore and transitional ore can be treated at the same time, and sulfuric acid does not need to be added additionally in the pressure leaching stage of high-silica magnesite ore. Fe<3+> in atmospheric pressure leaching liquid is hydrolyzed to form sediment, protons are released and then low-silica magnesite high iron ore is leached, and then Fe<3+> is further hydrolyzed to form sediment to be filtered out under the conditions of pressurization and heating, so that the consumption of sulfuric acid is reduced, and the content of iron in pressure leaching slag after solid-liquid separation is higher and can reach 58-65%; pressure leaching is realized by medium and low pressure equipment, so that the defects that high-pressure autoclave equipment is expensive and easy to scale are avoided. According to the method, iron slag and silicon slag can be naturally and conveniently separated in the technological process, and the content of silicon dioxide in the pressure leaching slag reaches 65-90%, so that leached slag can be effectively utilized, and efficient development and utilization for low-grade nickel laterite ore are realized; the method is simple in technological operation, safe, short in technological time and high in efficiency.

Description

technical field [0001] The invention relates to the field of hydrometallurgy, in particular to a method for extracting nickel and cobalt from low-grade laterite nickel ore by wet treatment. Background technique [0002] Laterite nickel ore is a nickel oxide ore formed by nickel-bearing peridotite after large-scale long-term weathering and leaching metamorphism in tropical or subtropical regions. Due to differences in geographical location, climatic conditions and weathering degrees, the types of laterite nickel ore in various parts of the world are different. exactly the same. [0003] The weathering process generally produces layered deposits in which complete or most complete weathering is present near the surface, gradually becoming less weathered with increasing depth, and finally terminating at some deeper depth as unweathered rock. [0004] Highly regolithed layers typically have most of the nickel they contain finely distributed in finely divided goethite grains. ...

AI Technical Summary

Problems solved by technology

However, this method has the following disadvantages and deficiencies: firstly, the leached slag obtained is a mixed slag of silicon and iron, and it is necessary to increase the cost to separate the mixed slag of silicon and iron, resulting in very poor economic benefits for the development and utilization of the leached slag; Limonite takes a long time, usually more than 4 hours, so the atmospheric pressure leaching equipment required is huge; third, the amount of saprolite ore used is twice that of limonite, which is contradictory to the ore belt composition of laterite nickel ore , it is well known that in laterite nickel deposits, the amount of limonite: the amount of saprolite ≥ 2:1

[0015] In short, in the invention patents of lateritic nickel ore hydrometallurgy mentioned above, the disadvantages of the high-pressure acid leaching (HPAL) process and the improved high-pressure acid leaching process are: complex High-temperature, high-pressure autoclaves and related equipment are expensive to install and maintain; the HPAL process consumes more sulfuric acid than is required to stoichiometrically dissolve the non-ferrous metal components in the ore; the HPAL process is limited to processing mainly It is the raw material of limonite; during the operation of the HPAL process, the autoclave is prone to fouling, and it needs to be shut down for cleaning regularly, and the operating rate is low

The disadvantages of the atmospheric pressure acid leaching process and the improved atmospheric pressure acid leaching process are: high sulfuric acid consumption; low nickel and cobalt leaching rates; long reaction time and huge equipment required

High-pressure acid leaching includes improved high-pressure acid leaching process and atmospheric pressure acid leaching process, including improved atmospheric pressure acid leaching process. The common disadvantage is that the amount of leached slag is large, and it is a mixed slag of silicon and iron, which cannot be economically and effectively developed and utilized.

Images