Selection of additives in firebrick

Resin bonded carbon magnetite brick because of its good thermal shock resistance and slag resistance of iron and steel industry, in particular applied basic oxygen furnace and electric arc furnace. Carbon has excellent performance such as high thermal conductivity, low thermal expansion coefficient, high heat shock stability, at the same time and wettability of the job of slag has good corrosion resistance and anti erosion ability. As is known to all, the brick body carbon easy oxidation, which restrict its use in high temperature, the oxidation of carbon from the beginning of the 300 DEG C, with the increase of temperature oxidation speed.

Ceramic materials (SiC, carbon silicon oxide) do coating in the flake graphite or carbon fiber, were impregnated with phosphate, cement foam board price and the use of surface glaze etc… These expensive methods used in the refractory brick have certain limitations, another method is through the steam treatment of fine particle boron, TiB2, ZrB2 and SiC and other materials to do thermal barrier coating on graphite or carbon composite material.

A common method of refractory brick is to add fine-grained antioxidant materials, such as in MgO C SiC, B4C, brick added metal Al, Mg and (or) Si to prevent or limit carbon at high temperatures (> 1400 C) oxidation. Also, these additives are expensive, and can not completely prevent the oxidation of carbon at low temperature. Coating solution by liquid mixing 60% solid and 40% made, wherein the liquid binder is phosphoric acid and ethanol (liquid solution 30%) mixture. The outer coating brush MgO C brick thickness is about 0.8mm, the sample coating drying at room temperature is about 10min. In practice, the ladle after 5h pre heated to 1200 DEG C, because of some difficulties in the process of steel-making and sometimes need a longer time.