Special steel drainage agent and preparation method thereof

Abstract

The invention provides a special steel drainage agent and a preparation method thereof and belongs to the technical field of metallurgical fireproof materials. The special steel drainage agent is prepared by following raw materials of, by weight, 22-75 parts of natural zircon sand with granularity of 0.1-0.5mm, 8-40 parts of chrome ore with granularity of 0.1-0.5mm, 15-35 parts of desert sand withgranularity of 0.3-0.6mm and 1-3 parts of liquid graphite. According to the invention, the pouring rate of a product can be effectively improved; compared with the existing drainage agent, the automatic pouring rate can be improved by 10% or over and the basic automatic pouring rate can reach 100%; requirements are met that there are many types of special steel currently, the difference of components is big and long-time smelting is required; and the drainage agent and better drainage effects for steel types in war industry, nuclear power and special high-quality products are achieved.

Description

technical field [0001] The invention relates to the technical field of metallurgical refractory materials, in particular to a drainage agent specially used for smelting special steel and a preparation method thereof. Background technique [0002] Ladle drainage agent, also known as drainage sand, is an unshaped refractory material with high refractoriness, stable performance at high temperature, and corrosion resistance to molten steel. It is a kind of bulk refractory material used to fill the ladle sitting brick and the upper nozzle. It is put into the ladle nozzle before the converter and electric furnace tap to prevent the molten steel from entering, and it will not be sintered as a whole under high temperature. It is released when steel is poured to guide the steel flow, which is the key link for the smooth progress of high-speed continuous steel casting. [0003] At present, with the transformation and upgrading of steel enterprises' products, the original general-to-e...

AI Technical Summary

Problems solved by technology

It can be proved by the facts that the drainage agent currently available in the market can basically meet the market demand in the use of ordinary steel, but in the use of special steel smelting, there are relatively large defects, and the smooth production cannot be guaranteed

The specific manifestations are as follows: 1) Chromium drainage agent: Although the self-opening rate can meet the use requirements under the smelting conditions of ordinary steel types, there are more alloy components in the smelting of special steel, which has a greater impact on the refractoriness of sand. In addition, the self-opening rate is difficult to stabilize under the high temperature state of long-term treatment

And due to the characteristics of chrome ore, it is easy to cause contamination of molten steel and poor fluidity caused by high heat transfer coefficient, which leads to many drainage agent accidents.

2) Silicon drainage agent: the expansion coefficient is large, the fluidity is poor after the slide plate is opened, it is easy to cause shed material, and affect the self-opening rate of the ladle

3) Although aluminum and magnesium drainage agents can achieve self-opening under the smelting conditions of individual steel types, they are likely to cause bonding between sand particles during the long-term high-temperature smelting process, resulting in blockage of the nozzle, which cannot meet the excellent performance requirements at all. Self-opening demand for steel

4) Zirconium-chromium drainage agent: Although the performance is stable under high temperature conditions, on the one hand, the particle size and composition of the zirconium raw materials used are special, and they need to be put into use after special treatment and purification and granulation in the early stage, resulting in high product costs. Enterprises cannot promote the use of

However, this technical solution has defects such as complex raw material composition and cumbersome preparation methods, and the actual self-opening rate for special steel drainage is lower than 85%, which needs to be improved