A kind of high-magnesium and low-silicon drainage sand for ultra-low carbon steel

Abstract

The invention discloses high-magnesium and low-silicon flow guiding sand for ultra-low carbon steel. The high-magnesium and low-silicon flow guiding sand is composed of raw materials including 96-97% of re-melt type fused magnesite and 3-4% of soda feldspars. The high-magnesium and low-silicon flow guiding sand for the ultra-low carbon steel is composed of following chemical components in percentage by mass: more than or equal to 94.5% of MgO, less than or equal to 1% of Al2O3, less than or equal to 3% of SiO2, less than or equal to 1% of CaO, less than or equal to 0.5% of Na2O and the balance of unavoidable impurities. All the raw materials are popular raw materials which are easily purchased on the market; the production process is simple and controllable; and the production cost is more than 15% lower than that of chromium flow guiding sand on the market. According to the flow guiding sand, the problems of poor heat insulation effect, crusting and the like of the flow guiding sand under a carbon-free condition are solved, and the sintering can be controlled; the recarburization problem of continuous casting molten steel is effectively solved; the good quality of a casting is guaranteed and the natural mobility of the flow guiding sand is good; the self-opening rate is more than 99.6%; a method for adopting an oxygen lance to boil to assist flow guiding is not needed and the quality of the molten steel is not influenced; the steel casting cost is not increased and the safety of equipment and operators is not threatened; and the continuous production efficiency of steelmaking is high.

Description

technical field [0001] The invention relates to drainage sand for ladles, in particular to a high-magnesium and low-silicon drainage sand for ultra-low carbon steel. Background technique [0002] The main function of drainage sand in steelmaking is: when "steel is filled", the upper surface of the drainage sand filled in the ladle nozzle produces a thinner sintered layer under the heat of high-temperature molten steel, forming a "shell". It prevents the infiltration and leakage of molten steel, which is beneficial to ladle transportation and processing of molten steel; when the steel is tapped, once the lower plate is opened, most of the unsintered drainage sand under the "shell" falls freely (drainage), resulting in a "shell" that loses support Body" is crushed by the static pressure of molten steel, and the molten steel flows out automatically (automatic opening and closing). If the pouring cannot be started automatically, it needs to be boiled by an oxygen lance to assis...

AI Technical Summary

Problems solved by technology

In the past, our main idea to solve this kind of problem was to reduce the free carbon content in the drainage sand as much as possible, that is, introduce as little carbonaceous materials as possible, but as long as carbonaceous materials are used, molten steel may increase carbon, and less carbonaceous materials will lead to Drainage sand has poor thermal insulation effect, crusting and other problems, so the overall effect is not ideal

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