Study On Properties And Structure Of Outer Lining Materials For Reducing Retort Of Magnesium Refining

Since the pidgeon process was invented for the magnesium produce in the 1940s, it becomes the most important for the magnesium produce, because there are some advantages, the cost of the plant is low, the built of the plant is fast and the quality of the product is good. For a long time, People used to prolong life and reduce the cost of production as the goal, they have done extensive research for Reduction retort manufacturing technology. In order to prolong the service life of reducing retort of magnesium refining, composite materials used in producing reducing retort and coating materials technology are both studied in this issue.SiC-based outer lining material for protective layer was introduced into founding reducing retort by using centrifugation. The effects of the species and the proper quantities of additive on the sintering and antioxidation characters of Al₂O₃-SiC refractory were discussed, thermoplastic phenolic resin was binder and proper additive was added, the samples which via mixing, molding and solidifying, were sintered at 1300℃, 1400℃, 1500℃for 3h. The results show that: The cold modulus of rupture and the crushing strength tend to rise with the bonding agent increasing in quantity. Taking into account the performance of products and production costs, so the content of the phenolic resin powder in the sample is 5wB% and the baking temperature at 220℃～250℃. Sintering and the physical properties of SiC-based materials are enhanced by adding 3wB% Fluorite or 4wB% Borax at 1300℃for 3h. And also Sintering and the physical properties of SiC-based materials can be enhanced by adding 2wB% Fluorite or 2wB% Borax at 1400℃or by adding 1wB% Fluorite or 2wB% Borax at 1500℃for 3h. The antioxidation can be enhanced by adding additive. The antioxidation of samples by adding additive Fluorite is better than by adding additive Borax. The best synthetical properties can be achieved by adding 2wB% Fluorite at 1400℃.High temperature antioxidation coating materials are coated in the out surface of reducing retort in the coating materials technology. Diatomite and quartz powder are used for the solute and the water glass or silica sol is used for solvent. The results show that: Adhesive properties are good by using sodium silicate as the solvent. Glaze layers with the role of antioxidation are generated in the surface sintered at 1100℃for 1h or 1200℃for 2h. And the dope used the silica sol as solvent has great mobility, but poor bond ability, and is not suit to coat in the out surface of reducing retort, and glaze layers are not generated after sintered at 1100℃for 1h.The bond strength can be enhanced by increasing the quantity of the diatomite and sodium silicate.