PROCESS FOR THE PREPARATION OF A MAGNESIUM CHLORIDE SOLUTION BY QUICK LIXIVIATION OF ASBESTOS TAILINGS

摘要

A process for the preparation of a magnesium chloride solution by lixiviationofasbestos tailings with an aqueous solution of hydrochloric acid having aconcentrationof about 20% by weight. In this process, the asbestos tailings used asstarting materialhave a granulometry equal to or lower than 62 mesh; the lixiviation is carriedout at atemperature close to the temperature of ebullition of the mixture, thistemperature ofebullition ranging between 115 and 120°C; and the lixiviation iscarried out withasbestos tailings and hydrochloric acid in such amounts that thestoichiometric ratiotailings/HCl ranges between 1.2 and 2.25. Under the above conditions ofoperation, thetime required to obtain almost entire transformation of the hydrochloric acidintomagnesium chloride and other metal chlorides is of about 5 to 15 min. andthere is nofiltration problem because of the presence of silica gel.