There are different types of molding materials for the production of ceramic abrasive tools in China. Some factories may have lower requirements for the strength of the wet billet. For example, the brown fused alumina price is used for drying and the aluminum base plate is used for drying. Suction cup, the workshop floor is relatively flat, wet billet transportation conditions are good, etc. Therefore, low-dextrin dosage and wet molding material are used to ensure a high dry billet strength to adapt to the dry billet handling and kiln loading Requirements.
Sapphire corundum smelting is performed in a short furnace reduction electric furnace. Heat is provided by electrical energy to melt the raw materials and allow the reduction reaction to proceed. We said that the reduction reaction in the smelting process is performed after the alumina is melted, and the reducing agent is solid carbon. The carbon monoxide gas generated by the reaction burns at the furnace mouth and escapes. After melting and reducing the bauxite, it becomes a corundum melt. After the smelting is completed, it will be cooled down to form a corundum frit.
This process is suitable for high-power electric furnaces, especially furnaceless lining electric furnaces, brown fused alumina which has the advantages of higher heat utilization rate, shorter melting time and convenient mechanical feeding. Control is to stop feeding in a certain period of time, generally in the middle of melting, so that the charge in the furnace is melted as much as possible, and the melting area is enlarged. During this period, the lower voltage, maximum power, and maximum temperature of the furnace liquid level are used to make the furnace liquid surface form a red cap. At this time, the control can be ended.
The performance of products is related to the processing quality, service life and safety of products. Under the condition of ensuring the use performance of products, raw materials shall be saved as much as possible and the cost of abrasives shall be reduced. Or in the case of no increase in cost, try to improve the product quality, without affecting the product quality, so that the formula has good mixing process performance and molding process performance, and is conducive to shortening the hardening time and improving the equipment productivity.
The dispersion degree of alumina raw materials and the calcination temperature of sintered corundum clinker can determine the basic properties, porosity and density of corundum clinker, which play a decisive role in the production process of brown aluminum oxide refractory products, mainly the firing temperature of products and the basic properties of products. In the production process of corundum refractory products, from alumina raw materials to corundum refractory products, the total volume shrinkage is about 24%.
When making such products, it is necessary to consider that the black corundum is a flexible wear-resistant material. The particle size can be slightly coarser than the original abrasive, and the proportion of the black corundum abrasive in the products can be increased as much as possible to increase the durability of the products. Black corundum abrasives are traditionally used for surface treatment of various workpieces, especially for stainless steel polishing.
More than 70% of bauxite resources in China are low-grade ores, and a few are high-grade ores. For many years, aluminum industry, refractories, high alumina cement, oil fracturing proppant, and brown aluminium oxide smelting use high-grade bauxite, resulting in high-grade ore in short supply, and a large number of powder ore, surface ore and low-grade ore are idle. In the bauxite calcination industry in the upstream of brown corundum smelting, bauxite block is still generally calcined in shaft kiln, resulting in high energy consumption and low yield of finished products.