in the crystalMicrosilicaIn the production process of magnesium-aluminum refractory castable prefabricated parts, the forming surface often rises, resulting in the phenomenon of product delamination, which will seriously affect the service life and yield of refractory products.
There are two kinds of SiO2 micropowder: one is made of high-purity silica, and the other is a by-product of producing metallic silicon or ferrosilicon.
But it needs to have stable physical and chemical properties, otherwise it will affect the performance of the product. Usually, the silica micropowder used in refractory materials refers to the latter, which is hollow spherical, active, non-agglomerated, and has good filling properties. The pozzolanic reaction and the natural formation of mullite with Al2O3 at high temperature are beneficial to the improvement of the strength of the castable.
In the production process of refractory prefabricated parts, it often occurs because of the batch replacement of the original silicon micropowder, resulting in fluctuations in the molding machine of the product. The solution to this problem is to first sieve the used silicon micropowder to uniformity. Secondly, in the process of mixing, increase the amount of retarder added, increase the amount of water appropriately, and at the same time properly extend the wet stirring time, and then shape; properly reduce the maintenance temperature of the product, so that the problem can basically be solved. Treatment. The obvious manifestation during this period is that the formed product rises and stratifies.