Method for collecting nickel and cobalt from laterite-nickel ore lixivium by using sulfide precipitation

Abstract

The invention provides a method for enriching nickel and cobalt from lateritic nickel ore lixivium. The method comprises the steps of concentration and pH value adjustment of pickle liquor, precipitation through adopting composite vulcanizing agent, solid-liquid separation, washing and filtrate processing. The composite vulcanizing agent consists of vulcanizing agent A containing hydrogen ions and vulcanizing agent B without the hydrogen ions. The method uses 1 to 95 percent of the vulcanizing agent A and 5 to 99 percent of the vulcanizing agent B in the composite vulcanizing agent. The pH value of the pickle liquor can be maintained or changed slowly through adjusting the pH value of the pickle liquor of the lateritic nickel ore to be a set value and slowly adding the composite vulcanizing agent, thereby acquiring a sulphide product enriched with nickel-cobalt. The mass ratio of nickel and the vulcanizing agent is between 1 to 1.6 and 5. A buffer system formed by the vulcanizing agent A and the vulcanizing agent B in the invention adjusts and controls changes of the pH value during the process of sulphuration precipitation, prevents iron chloride and magnesium chloride from being hydrolyzed into hydroxide and entering a sulphide, and improves the separation rate of nickel and cobalt and the separation rate of iron and magnesium; the acquired precipitation of the sulphide can be easily filtered; and the dosage of the vulcanizing agent is small.

Description

technical field [0001] The invention relates to a method for enriching valuable metals such as nickel and cobalt from laterite nickel ore, which belongs to the field of nonferrous metallurgy. Background technique [0002] Laterite nickel ore is a kind of nickel oxide ore, accounting for more than 65% of the total nickel reserves. Lateritic nickel ore can be divided into limonite type and silicon magnesium nickel ore type. The limonite type is located in the upper part of the deposit, with high iron, low nickel, low silicon and magnesium, but relatively high cobalt content, and should be treated by hydrometallurgy. The silicon-magnesium-nickel ore is located in the lower part of the deposit. The content of silicon and magnesium is relatively high, the content of iron and cobalt is relatively low, but the content of nickel is relatively high, so it should be treated by pyrometallurgy. The ore in the middle transition can adopt pyrometallurgy or hydrometallurgy. [0003] The...

AI Technical Summary

Problems solved by technology

However, there are some deficiencies in the existing method of using metal sulfide as a sulfidation precipitant: the obtained amorphous sulfide precipitated particles are very small, difficult to filter and wash, reduce equipment production capacity and work efficiency, and increase energy consumption; The amorphous sulfide obtained in the process is easy to adsorb and include magnesium, iron ions and their compounds, which reduces the separation rate of nickel, cobalt and base metals such as magnesium and iron during the vulcanization process; due to the precipitation of a large amount of iron sulfide and magnesium sulfide, the sulfide The dosage of the agent is relatively large; the leaching solution needs to be neutralized to a higher pH before the sulfide precipitation, and more neutralizers such as magnesium oxide, calcium oxide, and iron oxide are consumed; the pH value rises rapidly during the sulfide precipitation process, resulting in iron, A large amount of magnesium is hydrolyzed into iron hydroxide and magnesium hydroxide into sulfide products, which reduces the separation rate of nickel, cobalt, iron and magnesium

The above-mentioned deficiencies lead to low separation rate of nickel, cobalt, iron and magnesium in the process of sulfidation precipitation, large material consumption and high production cost