Application of foam flotation extraction for wastewater treatment and production of pure nickel sulfate

Abstract

The basic technological scheme for producing pure nickel sulfate (nickel sulfate of higher grades) from wastewater of the Severonickel Combine developed and tested on a single technological sample is described. The effluents of the combine can be characterized as relatively poor solutions suitable for obtaining nickel in the form of commercial products - seven-water nickel sulfate. The proposed technology includes the following main operations: oxidative hydrolysis for purification from Fe, AI, etc.; purification from Co; froth flotation extraction; control flotation; operations on separation of aqueous and organic phases; reextraction of nickel; regeneration of the extractant and crystallization of nickel sulfate. The obtained nickel sulfate meets GOST requirements for nickel sulfate of higher grades. The pre-feasibility study showed that the water treatment process is costless due to profit from sales of the resulting commercial products.