Resource-efficient technology for the utilization of serpentine technogenic waste with the production of magnesium oxide

Abstract

The article discusses the possibility of using serpentine and serpentine waste from Zhitikara deposit for the production of inorganic magnesium compounds: MgSO₄, Mg(OH)₂ and MgO. The aim is to produce magnesium sulfate, whose quality characteristics would further enable the production of high-purity magnesium hydroxide and magnesium oxide. A step-by-step process for obtaining magnesium compounds is proposed, initially starting with the purified magnesium sulfate solution, from which magnesium hydroxide and magnesium oxide can be produced. The proposed process differs from other known methods in the choice of reagent for neutralizing and purifying the initial sulfate solution to obtain high-purity magnesium hydroxide and magnesium oxide.

A technical and economic analysis was conducted on the efficiency of producing industrially important inorganic magnesium compounds from serpentine waste derived from the processing of chrysotile ore at Zhitikara deposit. The technology’s resource intensity, energy efficiency, and economic feasibility of the new approach to processing serpentine waste for the production of magnesium compounds are shown. The advantages of using an acid method in combination with thermally activated serpentine for neutralizing and purifying the initial sulfate leaching solution are discussed. Based on experimental data obtained from studying magnesium extraction processes from serpentine, as well as the production of magnesium hydroxide and magnesium oxide from the purified magnesium sulfate solution, and the technical and economic analysis of each stage, it is concluded that the proposed process becomes more efficient when the final product is magnesium oxide. The potential for utilizing technogenic waste containing serpentine for sustainable magnesium compound production is considered.

Keywords: serpentine, magnesium sulfate, magnesium hydroxide, magnesium oxide, resource efficiency.