Method for treating red soil nickel ore leaching liquid

Abstract

The invention discloses a method for separating nickel, magnesium and cobalt from red soil nickel ore leaching liquid based on a solvent extraction technology. The method is characterized by comprising the following steps of: adjusting the pH value of the leaching liquid to be between 3.5 and 5.5; extracting impurities by using diisooctyl acid phosphate, and adding into an organic phase; extracting the cobalt and the magnesium by using 2-ethylhexyl phosphonic acid single 2-ethylhexyl ester; making the nickel left in a water phase to separate the nickel from the cobalt and the magnesium; performing multi-stage reverser flow magnesium washing on the organic phase from which the cobalt and the magnesium are extracted by using sulfuric acid solution at slightly low concentration; adding the magnesium into the water phase, and making the cobalt left in the organic phase to separate the cobalt from the magnesium; and reversely extracting the cobalt by using sulfuric acid solution at slightly high concentration to obtain cobalt sulfate solution with high purity. In the method provided by the invention, a process is simple, a relatively expensive reagent is not required to be consumed, the nickel, the magnesium and the cobalt can be effectively separated from the red soil nickel ore leaching liquid, nickel sulfate solution and the cobalt sulfate solution which have high purity are produced, the nickel and the cobalt have high recovery rates and the magnesium can be recycled.

Description

technical field [0001] The invention relates to a treatment method for laterite nickel ore leachate, in particular to a method for extracting and separating nickel, magnesium and cobalt from the laterite nickel ore leachate. Background technique [0002] The lateritic nickel ore contains about 5-25% magnesium. During the leaching process of the ore to extract nickel, the acid used for leaching is mainly consumed to dissolve this part of the magnesium. About 90% of the magnesium in the ore enters the solution together with the nickel during the leaching process. In the subsequent metallurgical process of nickel, magnesium more or less enters the process along with nickel, and the separation of nickel and magnesium has become a major problem in wet nickel extraction. At present, the removal of magnesium in nickel sulfate solution generally adopts chemical precipitation method, and soluble fluoride such as sodium fluoride or ammonium fluoride is removed by reacting with magnesi...

AI Technical Summary

Problems solved by technology

Because nickel sulfate solution contains a large amount of magnesium, adopting this way of treatment requires consumption of a large amount of relatively expensive fluoride reagents on the one hand, and the separation method of magnesium is uneconomical; on the other hand, fluoride impurities will be introduced, which will affect the subsequent purification of nickel sulfate The process is affected; in addition, the nickel and cobalt in the solution cannot be separated

There is also a separation method that uses an exchange bed ion exchange resin to adsorb nickel but not magnesium. This method cannot separate nickel and cobalt. In addition, the operating cost of this method is relatively high

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