Environment-friendly type long-life fettling sand and production method thereof

Abstract

The invention relates to environment-friendly type long-life fettling sand, which is prepared from the following raw materials (by weight): 65-90 parts of sintered magnesia, 12-20 parts of a composite carbon source composed of carbon-containing resin powder and carbon black, 0.01-0.20 part of pitch fiber, 2.5-4.5 parts of a composite fluidizing reagent composed of refined naphthalene and allyl polyethenoxy ether, 0.2-1.5 parts of a composite sintering agent composed of silicon carbide micro-powder and borax, and 2.0-5.5 parts of a composite antioxidant composed of metallic aluminum powder and metallic silicon powder. In comparison with the prior art, the invention has the following beneficial effects: sintering time is short; scour resistance and spalling resistance are greatly improved; especially the environmental protection effect is prominent; smoke amount is obviously reduced; there is no peculiar smell; total service life is raised by 25-32%; fettling time is reduced; labor intensity is lowered; and win-win relationship between steel mills and refractory suppliers is realized.

Description

technical field [0001] The invention relates to the technical field of refractory materials used for furnace protection of iron and steel smelting converters, in particular to an environment-friendly and long-life repairing sand and a production method thereof. Background technique [0002] Furnace repair sand for converter protection is the most widely used refractory material for converter protection. Its service life directly affects the effect of converter protection and also affects the furnace life of the converter. [0003] The principle of repairing sand is the process of interfacial reaction between magnesia particles and carbonaceous materials softened and melted at high temperature. At the same time, to resist the erosion of molten steel, in order to make the formed magnesia-carbon sintered body strong and uniform in structure, a fluidizing agent should be added to reduce the surface tension of magnesia particles, so that magnesia particles can be fully sintered. ...

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Problems solved by technology

[0007] 2) Synthetic resin is made by the reaction of phenol and formaldehyde. It can be well mixed with refractory particles at room temperature. After carbonization, the residual carbon rate is high. The current production of magnesia carbon bricks and furnace sand is very large; but it The glassy network structure formed after carbonization is not ideal for the thermal shock resistance and oxidation resistance of refractory materials. In addition, the smell of phenol has also caused strong dissatisfaction from many parties.

[0009] 1) Since pitch, coal tar or phenolic resin are mainly used as carbon sources, a large amount of smoke is generated during the furnace repair process, which pollutes the environment;

[0010] 2) The corrosion resistance is not good, and the number of times of use is low, resulting in large consumption of refractory materials and high labor intensity;

[0011] 3) Affect the further increase of the overall furnace life, especially the low life of the converter for smelting pure steel;

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