Refractory process
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Author:haoyangnaihuo
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Published time: 2018-03-27
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According to the degree of compactness and appearance of products, there are sintering, melting and melt blowing. Sintering method is to pre-burn some of the raw materials into clinker, crushing and sieving, then mixing with the raw materials according to a certain ratio, forming, drying and firing. The purpose of the raw material burn-in is to burn out the moisture, organic impurities, and sulphate-decomposed gas, so as to reduce the firing shrinkage of the product and ensure the accuracy of the product's external dimensions. The raw materials need to be sifted after crushing and grinding, because the blanks are graded with powders of different sizes, which can ensure the closest packing and obtain compact bodies.
According to the degree of compactness and appearance of products, there are sintering method, fusion casting method and melt blowing method. The sintering method is to pre-burn some of the raw materials into clinker, crushing and sieving, then mixing with the raw materials according to a certain ratio, and forming, drying and firing. The purpose of the raw material burn-in is to burn out the moisture, organic impurities, and sulphate-decomposed gas, so as to reduce the burning shrinkage of the product and ensure the accuracy of the product's external dimensions. The raw materials need to be sifted after crushing and grinding, because the blanks are graded with powders of different sizes, which can ensure the closest packing and obtain compact bodies.
In order to homogenize the ingredients and granules of various raw materials and clinker, kneading is performed and a binder is added at the same time to enhance the binding strength of the blank. For example, the aluminum silicate raw material is added with the binding clay, the magnesium slate is added with the sulfite pulp waste liquid, and the silicon material is added with lime milk. Depending on the moisture content of the blank, semi-dry molding (about 5% moisture), plastic molding (about 15% moisture) and grouting (about 40% moisture) can be used. It is then dried and fired. The smelting method is the process of mixing raw materials and fine grinding and other processes, melting at high temperature, direct casting, cooling crystallization, annealing into products. Such as casting mullite brick, corundum brick and magnesium brick. Their green compact, high mechanical strength, high temperature structure strength, good slag resistance, the scope of use is constantly expanding. Melt-blowing is a method in which the ingredients are melted and blown with high-pressure air or superheated steam to disperse them into fibers or hollow balls. The products are mainly used as lightweight fire-resistant and heat-insulating materials. In addition, it can also be made into powdery or granular monolithic refractories. When it is used, it can be cemented with binders such as tar, asphalt, cement, phosphate, sulfate, or chlorinated salt. It can be used without molding and sintering.
