CHLORINATION OF COPPER, LEAD, ZINC, IRON, SILVER AND GOLD

摘要

This invention relates to a process for making the chloride of a metal from the sulfide of said metal in the absence of air and for a metal selected from copper, iron, lead, zinc, silver and gold. The process consists of three broad steps. First, forming an intimate mixture of finely divided sulfides of the metals with finely divided chlorides, the latter being in an anhydrous state. Second, heating the mixture to a temperature at which there is a rapid reaction converting the metal sulfides to chlorides and elemental sulfur in the state of a solid aggregate mixture. Third, recovering the formed metal chlorides from the aggregate mixture by conventional means. This invention is a process for forming a metal chloride of a metal or itscompound comprising forming a mixture of one or more metal chlorides being selected from the group consisting of ferric chloride, ferrous chloride, cupric chloride and cuprous chloride, and a metal or its compound, heating the mixture in the presence of a chlorine source to form the metal chloride and elemental sulfur and recovering the metal chloride from the mixture. Chlorine gas or sulfur chloride may be introduced into the mixture as an additional source of chlorine for reaction with the metal or its compound and for regeneration of a portion of the ferrous chloride or cuprous chloride into ferric chloride or cupric chloride. The technical field is the forming of metal chlorides from metals or metalcompounds such as oxides, ,carbonates and sulfates. The chlorination may be for various purposes, such as the recovery of metals from their ores or the manufacture of the chlorides for subsequent use. The present commercial methods for treating sulfide ores and concentrates involve roasting and smelting the sulfides in a series of operations which convert the sulfur to volatile sulfur dioxide. The metal values are effectively recovered in these operations. However, the very large volumes of sulfur dioxide produced are not always conveniently recovered, so that serious air pollution can result. As a substitute hydrometallurgical processes are being extensively developed. These processes convert the sulfide to solid elemental sulfur, with the metals being dissolved and recovered by various means.