Precipitação da nesqueonita a partir de solução de sulfato de magnésio para recuperação da magnésia

Abstract

The nesquehonite (MgCO3.3H2O) has shown to be increasingly attractive as a source of magnesium oxide (MgO), as it is a precipitate of easy filtration and which, after calcination, can produce a high-quality product. In addition to having high potential as CO2 sequestrating, the nesquehonite can also be used in the storage of nuclear waste and in the manufacture of functional and environmental protection materials. As part of nickel’s processing, magnesia (MgO) is used as a precipitating agent for MHP (Mixed Hydroxide Precipitation) in an intermediate stream of ore leaching by sulfuric acid, rich in nickel and cobalt, generating a concentrated stream in magnesium sulfate. In this context, the present work aims to obtain a reactive magnesia from a synthetic solution of magnesium sulfate of similar copmposition of the effluent from the nickel processing industry by nesquehonite precipitation. For this, the system was modeling using the software PHREEQC for different stoichiometric ratios of Mg2+/CO32-. The study suggests the possibility of using PHREEQC in the modeling of liquor magnesium carbonate for nickel’s processing with nesquehonite formation so that it can be later calcined and produce magnesia.