Pyrometallurgical processes are part of the extractive metallurgy and are also called dry-track operations, its objective is to obtain and purify metals using high temperatures, this process is the oldest in the recovery of metals, and 10,000 years ago, cavemen use fire to obtain metals.
In this article we will mention some concepts of this part of extractive metallurgy, we can start by mentioning some operations:
In this operation the humidity of the mineral is eliminated, usually when passing hot air over the product, in this way the humidity is transferred to the air cooled by the product and therefore the mineral lowers its humidity content considerably.
In this operation the oxides contained in the ore are decomposed, to do this a very high temperature is required, but has to be lower than the melting point of the mineral, this causes the thermal elusion, which eliminates the sterile matter in gaseous form, to facilitate the reduction.
The roasting consists in the change of the chemical composition of a mineral, through high temperatures, but without changing its solid state, the objective here is not to eliminate the sterile matter, is to transform it. Toasting can also be conceptualized as a calcination with a chemical decomposition.
It consists of obtaining free metal from metal oxides and it does in a furnace where a reducer in many cases coal, or hydrogen is added, we must mention that many times in nature the metals are already in the form of oxides, and some others in the form of sulfides, the sulfides must be toasted to turn them into oxides, and in the case of carbonates a calcination is required.
The fusion is a process of concentration where the light residues join and form an element called slag, with the fusion the solid state of the elements is modified by the use of high temperature, converting them into liquids.
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