Technical properties and processing of silica fume

Wollastonite also has unique technical properties. For example, after using wollastonite raw materials, the shrinkage rate of the billet can be effectively reduced. Moreover, it can reduce the hygroscopic expansion of the billet and prevent the later dry cracking of the ceramic billet. The billets containing siliceous limestone also have higher mechanical strength and lower dielectric loss. Introduction of wollastonite body, mature more quickly in the sintering process, can make the body in more than ten minutes to dozens of minutes mature, greatly reduce the heat loss of unit products, its firing cycle also from the last 90 hours, reduced to just 50 minutes. Wollastonite was first introduced into the glaze brick blank formula, which reduced the heat loss from 3,600 calories/kg to 1,850 calories/kg. In addition to glazed tile, silica limestone raw materials have expanded its application scope. Its effect of saving energy and reducing consumption has been widely recognized in the ceramic industry.

The purification of wollastonite is to select harmful iron ore and reduce the limited mineral content of calcite, dolerite, garnet and quartz. The purification methods include manual selection, screening, magnetoelectric selection, flotation and combined selection. As a new material of industrial concern, wollastonite comes from its special needle-like structure. In addition to other mineral powders should have fine granulation and surface activity, and should maintain as long diameter ratio as possible. Natural wollastonite products can be divided into block particles, common powder, fine powder, ultra-fine powder and needle-like powder according to the particle size. The preparation method of powder is mainly mechanical crushing. The equipment used in the copying and processing of silica limestone is gravel grinder, airflow mill, and tell the mechanical impact magic machine. Mechanical crushing can be divided into dry method and wet method. Wet method can save energy and protect fiber length-diameter ratio. The dry law disagrees with the reunion. The ultrafine powder of siliceous limestone with high aspect ratio can be obtained by shearing force.