Process development for impurity removal from a tin gravity concentrate

A new process for the removal of impurities from tin gravity concentrate using flotation has been developed in this work. Removal of zircon, tantalum and columbite from a tin gravity concentrate has been accomplished by direct tin flotation using a mixture of sulphosuccinate collectors modified with fatty alcohol ester sulphate, and depression of impurities using organic acids and sodium silicate. When using this method, more than 90% of the impurities were removed from the gravity concentrate. The concentrate was upgraded from 58% to approximately 90% SnO2. jor factors affecting selective flotation of tin from tantalum, niobium and zircon were the degree of collector modification, type and amount of depressant, and the flotation pH. The process has been confirmed in a number of continuous batch tests.