Application of fused magnesia

At present, the process method of producing fused magnesia by electric furnace is generally used to smelt the fused magnesia directly. The disadvantage is that the power consumption is large. Furthermore, 80 kg of carbon rod is required for each ton of qualified fused magnesia (purity higher than 96.5%) smelted by the existing process. Relevant data (Special Refractory Materials, Magnesia Technology, and Papers on High-temperature Refractory Materials) show that the light magnesia is heated by electric arc, It can generate cubic crystal, i.e. heavy magnesium oxide with a melting point of 2800 ℃, i.e. fused magnesia. The fused magnesia can be produced by recrystallization of magnesia produced by furnace melting. The clinker particles in the kiln are formed under the action of the liquid phase (some data call it melt), and the liquid phase forms a capillary bridge outside the crystal. The liquid-phase capillary bridge plays two roles: one is to combine the particles, and the other is to act as the medium between the medium-electric fused magnesia, so that CaO and C2S are fused

C3S is generated by diffusion in the molten state. The strength of the particles is determined by the strength of the capillary bridge. The strength of the bridge, that is, the force connecting the particles, increases with the increase of the surface tension of the liquid phase and the decrease of the particle diameter. The number of capillary bridges is inversely proportional to the square root of particle diameter. In order to agglomerate well, there must be enough liquid phase, and the particles should be evenly distributed in the liquid phase to form a higher surface tension, a lower liquid viscosity, and a suitable granulation time and temperature. Chemically bonded refractory mud is a mixture composed of refractory fine aggregate and chemical binding agent (inorganic, organic-inorganic, organic). The delivery state can be either slurry or dry, hardening below the ceramic bonding temperature. According to the hardening temperature, the refractory mud can be divided into two types: gas hardening and thermal hardening. The gas-hard refractory mud is usually prepared with water-glass and other gas-hard binders. Thermally hard fused magnesia refractory mud is usually prepared with phosphoric acid or phosphate and other thermosetting binders. After hardening, this kind of refractory clay has not only high strength at various temperatures, but also small shrinkage, tight joints and strong corrosion resistance.