Nickel sulphide concentrate processing via low-temperature calcination with sodium chloride. Part 1 – Identification of interaction products

Abstract

The low-temperature calcination of nickel sulphide concentrates with sodium chloride and subsequent hydrometallurgical processing is a promising alternative methods. This study aims to identify the interaction products of sulphide nickel concentrate components with sodium chloride at temperatures of 400–450 °C. Thermodynamic studies have demonstrated that nickel sulphates, chlorides, and oxides are the probable nickel-containing products of the interaction between nickel sulphide and sodium chloride in the presence of oxygen. At 350–450 °C, the formation of nickel sulphate is preferred; as the temperature increases, the probability of oxide formation also increases. We experimentally confirmed that nickel sulphate is the main nickel-containing product of the reaction between nickel sulphide concentrate and sodium chloride at 400 °C, and the reduced nickel oxide and chloride content was identified in the calcine. The other main products included iron oxide (III) and sodium sulphate. During calcination at 400 °C, up to 75% of the sulphur contained in the concentrate was bound to sodium sulphate.