Submerged-arc furnace for phosphorus production

A smelting reduction furnace (English: Submerged Arc ( - resistance) Furnace, SAF) is a special form of the electric arc furnace.

Area of ​​application

Typically used as the initial smelting of alloy constituents, ferro alloys, or so-called aggregates. The products of smelting reduction furnaces are mainly used in metallurgy application to convert, for example, unwanted components of a melt into slag and thereby remove from the melt.

On a larger scale nickel, calcium carbide or metallurgical silicon are melted, the furnaces are each designed specifically for the melt.

Another application of enamel - reduction furnaces is the reaction of calcium phosphate in the form of the mineral apatite or phosphorite with coke and silica sand to about 1400 ° C to obtain white phosphorus at temperatures.

Heat generation

In contrast to the electric arc furnace with the unloaded between the weld pool and electrode arc, the electrode is immersed into the slag. The heating is primarily caused by the current flow through the electrical resistance acting as a slag and partially inside the slag forming arcs. The melt itself need not be electrically conductive.

Usually, the supplied with three-phase alternating current 3 - electrode design is in star connection with round furnaces, the electrodes are positioned itself in an equilateral triangle.

The melt is electrically conductive, the number of electrodes can be reduced to one. Such furnaces are operated with direct current; the melt represents the antithesis