What is the role of silicon calcium alloys in the steelmaking process?

Silicon calcium alloy is a composite alloy composed of elements silicon, calcium and iron. Silicon calcium alloy is an ideal composite deoxidizer and desulfurizer. Silicon calcium alloy is widely used in the production of high-quality steel, low-carbon steel, stainless steel and other steel grades and special alloys such as nickel-based alloys and titanium-based alloys; it is also suitable as a warming agent for converter steel refining workshops; Silicon calcium alloy can also be used as an inoculant for cast iron. and additives in the production of ductile iron. Since about 1907, silicon-calcium alloys have been produced by the electrosilicothermic method.

 

Product specifications mainly include 0-3mm, 200 mesh, 150 mesh, 100 mesh, and various specifications and sizes can also be provided according to customer requirements.

Purpose

Both calcium and silicon have a strong affinity for oxygen. Calcium, in particular, not only has a strong affinity with oxygen, but also has a strong affinity with sulfur and nitrogen. Therefore, silicon-calcium alloy is an ideal composite colloidal oxygen agent and desulfurizer. Silicon alloy not only has strong deoxidation ability, and the deoxidized products are easy to float and discharge, but also can improve the performance of steel, and improve the plasticity, impact toughness and fluidity of steel. At present, silicon-calcium alloys can replace aluminum for final deoxidation. Applied to high-quality steel. Special steel and special alloy production. For example, steel grades such as rail steel, low carbon steel, stainless steel, and special alloys such as nickel-based alloys and titanium-based alloys can all use silicon-calcium alloys as deoxidizers. Silicon-calcium alloy is also suitable as a warming agent for converter steel refining workshop. Silicon-calcium alloy can also be used as an inoculant for cast iron and an additive in the production of ductile iron.

 

Production

Silicon-calcium alloy is prepared by reducing silicon dioxide and calcium oxide with carbonaceous reducing agent in a reducing electric furnace. The main raw materials are silica, lime, coke, etc. feeding method) and two-step method. In fact, the methods of industrial production of silicon-calcium alloys are all realized by using CaC2 as a transition product. The density of silicon-calcium alloy is slightly smaller than that of slag, and the silicon-calcium alloy is basically concentrated in the upper part of the molten pool during the smelting process, which is the characteristic of smelting silicon-calcium alloy. Special measures should be taken to separate it from the slag when it is released. According to the above analysis, there are three processes for smelting silicon-calcium alloy by electric carbothermic (reduction) method, namely, mixed feeding method, layered feeding method and calcium carbide method. The electro-silicothermal (reduction) method is also one of the methods for producing silicon-calcium alloys.