What are the aspects of chemical corrosion of ramming materials?

Ramming material refers to unshaped refractory materials that are constructed by ramming (manual or mechanical) and hardened under the action of heating above normal temperature. It is made by adding water or other liquids by mixing. According to the material, there are high alumina, clay, magnesia, dolomite, zirconium and silicon carbide-carbon refractory ramming materials. The chemical corrosion of ramming materials mainly includes the following several aspects.

(1) Corrosion of molten iron. The furnace lining is mainly corroded by carbon in molten iron. SiO2 plus 2C—Si plus 2CO corrodes and smelts gray cast iron, both in ductile iron, and more severe in smelting ductile iron.

(2) Slag invasion. CaO, SiO2, MnO, etc. in scrap iron and steel are easy to form low-melting slag, especially CaO damage is greater. Therefore, attention should be paid to the cleanliness of the raw materials used, and the amount of slag generated by severely oxidized thin-walled waste is more. , It should be used as little as possible or in batches, and less added to each furnace.

(3) Refractory slag. The high melting point slag is caused by the original aluminum. It reacts with SiO2 in the furnace lining to form mullite (3A12O3-2SiO2), and the melting point is 1850 degrees Celsius. Therefore, the aluminum in the original guess should be removed. , so as to avoid the formation of high melting point slag.

(4) Auxiliary agent. If slag coagulant or slag flux is used in the smelting operation, it will aggravate the corrosion of the furnace lining, so it should be avoided as much as possible.

(5) Carbon accumulation. The carbon accumulation is on the ice face of the furnace lining, and even accumulates in the thermal insulation layer. The reason for the carbon accumulation is that oil-impregnated wastes, such as chips, are used in the initial stage of furnace reuse, because the furnace lining is not fully During sintering, CO enters the back of the furnace lining, and the 2CO-2C plus O2 reaction occurs. The generated carbon accumulates in the ice face of the furnace lining or in the pores of the thermal insulation material. When carbon accumulation occurs, it will cause the furnace body to earth leakage, and even the coil will catch fire. flower.