Process for removing chromium from laterite-nickel ore

Abstract

The invention discloses a process for removing chromium from laterite-nickel ore. The process comprises the steps of 1, an ore washing process and 2, a chromium screening process, specifically, the laterite-nickel ore is subjected to the ore washing to separate raw ore pulp with the particle size of -1.5 mm, and then coarse-fine classification is carried out to form coarse raw ore pulp with the particle size of +0.058 mm to -1.5 mm; the coarse raw ore pulp enters a spiral chute to obtain tailings and concentrates; the concentrates enter a first-stage shaking table for screening to obtain first-stage shaking table tailings and first-stage shaking table concentrates; the first-stage shaking table concentrates enter a second-stage shaking table for re-screening to obtain second-stage shakingtable tailings, second-stage shaking table middlings and second-stage shaking table concentrates; and the second-stage shaking table middlings is returned to the second-stage shaking table for re-screening after being subjected to grinding, and the first-stage shaking table tailings and the second-stage shaking table tailings are subjected to magnetic screening after being subjected to grinding. According to the process for removing the chromium from the laterite-nickel ore, the content of chromite in the laterite-nickel ore raw ore is reduced, the recovery rate of the chromium concentrates ishigh, the abrasion of the chromium concentrates to laterite-nickel ore wet smelting equipment is reduced, and meanwhile, part of the qualified chromium concentrates is obtained.

Description

technical field [0001] The invention relates to the technical field of ore dressing, in particular to a process for removing chromium from laterite nickel ore. Background technique [0002] Laterite nickel ore is a loose clay-like polymer containing oxides of nickel, iron, magnesium, cobalt, silicon, aluminum and other elements formed by nickel-bearing olivine bedrock through long-term geological processes. The iron element contained in it is +3 due to serious oxidation. Its overall appearance is reddish brown, so it is named lateritic nickel ore. Laterite nickel ore is a refractory type of oxide ore, which cannot be effectively enriched by ore dressing. At present, the development of lateritic nickel ore mainly includes fire method (mainly RKEF nickel-iron process) and wet route (mainly high pressure acid leaching process). For the limonite layer with lower nickel grade in lateritic nickel ore, it cannot be utilized in pyrotechnics, and can only be processed by hydrometal...

AI Technical Summary

Problems solved by technology

Hydrometallurgy, especially high-pressure acid leaching, will cause corrosion to the equipment used. In addition, the associated spinel-type chromite in laterite nickel ore also has a strong abrasive effect on the equipment. Therefore, hydrometallurgy of laterite nickel ore needs to be used Expensive corrosion-resistant equipment increases equipment costs and brings unpredictable safety risks

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