process for beneficiation of tantalum and columbium content of zinnschlacke

摘要

1287010 Tantalum and columbium in tin slags KAWECKI BERYLCO INDUSTRIES Inc 5 Dec 1969 [5 Dec 1968] 59668/69 Heading C1A The tantalum and niobium contents of tin slags are upgraded by smelting the slag with carbon to reduce at least the iron, tantalum and niobium contents and forming the Ta and Nb carbides. After pouring off the supernatant slag, the product is comminuted to at least 50% minus 350 mesh (Tyler) and a maximum of 10% plus 100 mesh, and mixed with a mixed acid of HCl in at least the stoichiometric quantity required to form chlorides of the Fe, Ca, Al, Ti and W, and HF in stoichiometric quantity required to form SiF 4 from the silicon content, and in a concentration of 2 to 5À5% weight of mixed acid. The carbide product is then heated in the mixed acid for a time sufficient to solubilize the iron, calcium, silicon, Al, Ti and W contents of the carburized slag, i.e. about 100‹ C. for 3-4 hours, and the solid residue is separated out and calcined in air at 600‹ to 900‹ C.