Unfired magnesia-calcium-carbon brick and preparation method thereof

Abstract

The invention discloses an unfired magnesia-calcium-carbon brick which is prepared from the following raw materials in parts by weight: 60 to 100 parts of magnesia-calcium sand, 20 to 40 parts of fused magnesia, 5 to 10 parts of crystalline flake graphite, 3 to 8 parts of zirconium oxide micro powder, 3 to 8 parts of silicon carbide micro powder, 2 to 5 parts of phenolic resin and 2 to 5 parts of modified asphalt. The preparation method comprises the following steps: (1) weighing the raw materials; (2) carrying out dry mixing on magnesia-calcium sand, fused magnesia and zirconia micro powder, then adding phenolic resin and modified asphalt, carrying out wet mixing, then adding the crystalline flake graphite mixture, and finally adding the silicon carbide micro powder mixture; (3) pouring into a mold, pressurizing to form a blank, and baking; and (4) dipping with paraffin, and packaging by adopting double-layer plastic package. The unfired magnesia-calcium-carbon brick prepared by the preparation method is large in volume density, high in strength, difficult to hydrate and crack, strong in erosion resistance, good in high-temperature stability, difficult to peel off during use, long in service life and applicable to steel ladles of high-grade steel such as stainless steel, special steel and the like.

Description

technical field [0001] The invention relates to the technical field of refractory materials, and more specifically relates to an unfired magnesia-calcium-carbon brick and a preparation method thereof. Background technique [0002] Unfired magnesia-calcium-carbon brick is an alkaline refractory material made of MgO, CaO and C as the main components, which is pressed under high pressure and dried by electric heating. It has excellent slag erosion resistance, slag permeability, and thermal shock stability. and thermal conductivity. [0003] At present, unfired magnesia-calcium-carbon bricks are widely used in stainless steel refining VOD furnaces, AOD furnaces and LF furnaces. They have broad market prospects and will play a huge role in promoting the technological progress of my country's iron and steel enterprises. However, the corrosion of unfired magnesia-calcium-carbon bricks for AOD furnaces is mainly due to the dissolution and penetration of the silicate liquid phase, w...

AI Technical Summary

Problems solved by technology

However, the corrosion of unfired magnesia-calcium-carbon bricks for AOD furnaces is mainly due to the dissolution and penetration of the silicate liquid phase, while unfired magnesia-calcium-carbon bricks for VOD ladles are subjected to many chemical media and mechanical forces during use. Erosion will cause the brick body to crack and deform until the brick body falls off; at the same time, due to the easy hydration characteristics of magnesium-calcium refractory materials, it has become an important issue in the promotion of magnesium-calcium refractory materials