Electrode paste, as a conductive material for electric furnace equipment such as ferroalloy furnaces and calcium carbide furnaces, relies on the heat inside the mineral thermal furnace to complete the roasting process. The key is to match the roasting speed with the electrode consumption speed. With the development of mineral thermal furnace technology, it has evolved towards large-scale and enclosed direction, making large electric furnaces the mainstream, and electrode paste is mostly enclosed paste. After being loaded into the electrode cylinder, the electrode paste is self coking and sintered into electrodes, which can be continuously used and extended while being used, and sintered into shape.
Electrode paste is divided into standard paste and sealed paste. Standard paste is used in open type calcium carbide furnaces, using ordinary calcined anthracite and metallurgical coke as raw materials, and medium temperature asphalt as a binder. Its characteristics are high ash content, high electrical resistivity, slow sintering speed, but low price. Sealed paste is used in sealed mineral thermal furnaces, with ordinary calcined smokeless coal, artificial graphite chips, and petroleum coke as the main raw materials. Coal tar is added to coal tar pitch to reduce the softening point. It has good electrical and thermal conductivity, low ash content, fast sintering speed, and is relatively expensive.
The production process of electrode paste mainly includes raw material calcination, crushing, screening, grinding, mixing and shaping. The main raw materials include residual anode, anthracite, graphite flakes, petroleum coke, and asphalt coke, with asphalt and coal tar as binders. The electrode paste is roasted in the operation of the mineral thermal furnace, without involving roasting and subsequent graphitization processes. The ash content of electrode paste should be less than 10%, the moisture content should be less than 1%, the particle size composition should be suitable, and the volatile content of about 13-19% is more appropriate. The raw materials for manufacturing electrode paste should mainly be anthracite and coke, with a softening point of 55-70 degrees for asphalt. The main domestic manufacturers of electrode paste include Luoyang Longxin Furnace Material, Gongyi Sanjing Carbon, Sunshine Carbon, Qinjin Graphite, Rongxin Carbon, etc.