PROCESS FOR THE PURIFICATION OF PYRITE CINDERS FROM NONFERROUS METALS, FROM ARSENIC AND FROM SULFUR

摘要

A process for the purification of pyrite and pyrrhotite cinders from nonferrous metals, from arsenic and from sulfur. The process is characteristic in that the reduction of the hematite to magnetite is carried out in a fluid bed by direct injection of a hydrocarbon fuel and air in deficiency, at 850 DEG -950 DEG C. and with contact times from 15 to 45 minutes, up to a degree of reduction equal to from 10-90 percent, and in the presence of small quantities of HC1. The chlorination and reoxidation of the thus produced hot cinders is carried out in a fluid bed reactor with air and a chlorinating agent, at temperatures of from 650 DEG -1,000 DEG C., preferably at 850 DEG -950 DEG C. with contact time from 20 to 150 minutes, and that the gases leaving the reactor contain less than 0.5 percent by volume of free oxygen.