Calcium silicon particles are used as deoxidizers in steelmaking, and its main elements are ca (24-31%) and si (55-65%), which are obtained by reducing silicon dioxide and calcium oxide with carbonaceous reducing agents in smelting . The raw materials are silica, lime, coke, charcoal and bituminous coal, and the production methods mainly include mixing method, layered feeding method, silicon thermal method and so on.
Since calcium in silicon-calcium particles has a strong affinity with oxygen, nitrogen, hydrogen, sulfur and carbon in molten steel, silicon-calcium particles are mainly used for deoxidation, degassing and carbon fixation of molten steel. Adding calcium silicon to molten steel will produce a strong exothermic effect. Calcium turns into calcium vapor in molten steel, which has a stirring effect on molten steel and is beneficial to the floating of non-metallic inclusions. After the silicon-calcium alloy is deoxidized, non-metallic inclusions with large particles and easy to float are produced, and the shape of non-metallic inclusions also changes. and nature. Silicon-calcium alloy produces clean, low-oxygen, and low-sulfur high-quality steel. And special-performance steel with low oxygen and low sulfur. Adding silicon-calcium particles can eliminate the problems of nodulation at the ladle nozzle and clog the continuous casting molten steel tundish nozzle with aluminum as the final deoxidizer.
In the refining technology outside the furnace of steel, silicon-calcium particles or core wires are used for deoxidation and desulfurization, so that the oxygen and sulfur content in the steel is reduced to a shallow level, and they exist in the steel in the form of sulfide. It can also control molten steel while improving the utilization rate of calcium. In the production of cast iron, in addition to deoxidation and purification, silicon-calcium particles also play an inoculating role, helping to form fine-grained or spherical graphite, so that the graphite in gray cast iron is evenly distributed, reducing the tendency of whitening, and can increase silicon and desulfurization, Improve the quality of cast iron.
The existing silicon-calcium particles are used as deoxidizers in steelmaking, the main elements are Ca (24-31%) and Si (55-65%), which are reduced to silicon dioxide by carbonaceous reducing agents in submerged arc furnaces and Oxidized. Calcium is obtained from silica, lime, coke, charcoal and bituminous coal. Its production methods mainly include the mixing method, layered feeding method, silicon thermal method, and so on. Taking the layered feeding method as an example, the basic process is 1. After coming out of the furnace, smash, add new material, pound the furnace to ventilate, and raise the temperature with a slow fire (about 1-2 hours); 2. Mix the lime and cola evenly, add the electrode Stew around; 3. After the lime is melted, add new material, add silicon dioxide to destroy CaC2 after simmering for half an hour, so as to form silicon-calcium particles and come out of the furnace.
During the production process of silicon-calcium particles, the raw materials are mixed and stirred evenly and put into a special induction furnace for heating for about two and a half hours. The furnace temperature is about 1800°C. During the smelting process, the charge is stirred according to the furnace conditions. , and break into silicon-calcium particles after cooling.
As a deoxidizer for steelmaking, silicon-calcium particles have good fluidity in molten steel, fewer nodulation accidents, and significantly reduced pollution. Compared with other deoxidized alloy products, silicon-calcium particles are not easily differentiated and have stable quality labels.