A capability of control of melting alumina composition by means of a value of phase volt-age dc component is shown.
The presence of even harmonic components of current and, above all, the harmonic component with a frequency of 100 Hz is possible only if the electric circuit elements, the resistance of which depends on the direction of current. Such elements may be a contact of electrode with the melt and the electric arc AC. Change the relative content in electrode current harmonic component with a frequency of 100 Hz dependent from the penetration of the electrode in the melt and the degree of electric arc development.
On example of phosphoric and carbide furnaces is considered character of change and the nature of existence a constant component (Ucc) in a phase voltage of ore-smelting furnaces with closed furnace throat. The size and direction Ucc depends on a ratio of electrode processes chemical interaction with reactionary zone components and a degree of development and a condition of burning electric arch.