Pyrometallurgy

A subfield of extract changes in the materials that allow for the recovery of precious metals. Pyrometallurgical processing can result in products that can be marketed, such as pure metals, intermediate compounds, or alloys that are good feedstock for more processing. The oxides of less reactive elements including iron, copper, zinc, chromium, tin, and manganese are examples of elements that may be recovered by pyrometallurgical methods. Calcinating, roasting, smelting, and refining are the broad categories into which pyrometallurgical operations fall. Energy is needed to maintain the temperature for the majority of pyrometallurgical operations. The energy is often produced by burning. Typically, combustion or electrical heat are used to produce the energy. The term "autogenous" refers to a process that can maintain its temperature only by exothermic reaction i.e., without the need of fuel or electrical heat and that has a sufficient amount of material in the feed. Some sulphide ores' processing makes use of the exothermicity of their burning.