Gas Purging Systems

METTOP FIS offers gas purging systems to improve the efficiency of different furnace types in nonferrous metallurgy. The system consists of a set of purging elements, such as porous plugs, and a gas control and regulation unit. Porous plugs are used for example to introduce additional gas (e.g., N₂) into the melt.

The gas flow for each individual plug is controlled by the gas control unit. Purging programs for different metallurgical processes and single process steps are developed to obtain the maximum benefits from gas purging.

 

In drum type furnaces, it is also possible to equip the porous plug sets with an exchangeable mechanical system. This enables the plugs to be changed even under hot furnace conditions. The exchangeable system is cooled on the outside with compressed air and each plug contains a residual thickness control, based on thermocouples, that indicates the appropriate time for exchange.

In copper metallurgy, anode furnaces produce a low oxygen and sulphur containing anode copper, typically through an oxidation and reduction step. However, the reaction kinetics is slow and additional heat is required to maintain the necessary temperature.

During the two step converting process, oxygen enriched air is injected through a row of tuyeres into the copper matte received from a primary smelting unit. In the first step the iron content is oxidized into a fayalithic slag, which is formed by silica addition. During the second step, the remaining copper sulphide is converted into blister copper with a final sulphur content of approximately 200 ppm. The overall efficiency of this process is determined by the total reaction time, the slag quality and quantity and the chemistry of the final blister copper.