This article is following the lastest article talks about the last choices of Magnesia carbon brick raw materials.
4. The reaction mechanism of antioxidant
There are three methods for preventing oxidation of magnesium carbon bricks: First, external coating anti -oxidant, forming glass material to prevent carbon oxidation at low temperature, but lost its effect at high temperature. The second is the method of density, changing the particle size, binding agent, and the method of increasing the molding pressure. The third is to add a small amount of metal or non -metallic compound additives that are more prone to oxidized than oxidation to inhibit the oxidation of carbon. Such as: aluminum, silicon, magnesium, calcium, etc., or binary or ternary alloys such as aluminum magnesium, silicon, magnesium calcium, aluminum magnesium calcium instead of metal, as well as compounds such as silicon carbide, boron carbide, calcium boron, and titanium dioxide. It plays a role in preventing carbon oxidation. The antioxidant causes small pores at a lower temperature, reducing the breathability of magnesium carbon bricks, thereby preventing the entry of oxygen. At high temperature, the high temperature strength of the bricks can be enhanced. Metal aluminum and silicon powder form a variety of reaction products between 1000 degrees and 1400 degrees. After filling with carbon oxidation, the remaining stomach is filled, thereby improving high temperature intensity and improving antioxidant performance. The high temperature intensity of the brick body of metal aluminum at 1120K is lower than the high temperature strength of the addition of metal silicon and aluminum, while the 1568K is the opposite, but its water resistance is decreased as the silicon increases.
Adding silicon carbide can improve its antioxidant performance, but if the amount of addition is too large, it reduces its corrosion resistance. It is more obvious at high temperature. Adding titanium dioxide is based on the increase in iron water to increase the viscosity of iron, thereby increasing corrosion resistance, but it is not obvious in the turntable.
Adding metal calcium powder can improve the antioxidant performance of magnesium carbon bricks in the low temperature and medium temperature zone. The metal magnesium reactive metal magnesium can be oxidized and generated. The residual expansion is low, which improves the volume stability, so the use of the steel port and the slag line is effective.
