Silicon Brick Production Process
The first, determine the ratio of raw materials and particle composition.
The raw materials for making silica bricks are silica bricks and waste bricks containing more than 96% of Sio2, as well as limestone, mineralizers and organic binders.
The addition of waste silicon bricks can reduce the firing expansion of the bricks, but at the same time reduce the refractoriness and strength of the products and increase the porosity. Therefore, the amount of waste silicon bricks to be added should be determined according to different conditions. The larger the single weight of the refractory product, the more complicated the shape, and the more the amount added. Generally should be controlled at 20%.
Lime is added to the billet in the form of lime milk,which acts as a binder to increase the strength of the brick after drying and acts as a mineralizer in the firing. The lime used to produce silica bricks requires an activity of Cao>90%,a carbonate of no more than 5%,and an Al2o3+Fe2o3+Sio2 of no more than 5%.The blockiness of line is about 50mm,and the power is as small as possible.
The mineralizers used in production mainly include rolled steel sheets (iron scales).The quality requirement is:fe203+Sio2>90%,and must be finely pulverized in the ball mill,less than 80% of the power of less than 0.088mm.
Sulfite pulp waste liquid is often used as a binder.
The general principle for determining the composition of silica brick particles should be:
1) When selecting critical particles ,it should ensure that the brick get the maximum density and the heating volume is stable .
2) The critical particles in the billet are small and there are many fine particles.
3)when using several kinds of silica mixed ingredients,the particle size should be determined according to the difference in the height of the violent expansion temperature,and the coarse expansion temperature is high,and the coarse particles are added.
4)The nature of the raw material must be considered to determine the particle composition.The dense silica raw material particles may be coarser,and vice versa.In production,the critical particle size of the general silica brick is preferably 2mm~3mm,and when the pulse quartz is used as the raw material ,the largest particle is 2mm.
How to Shape Silica Bricks
The characteristics of silica brick molding are mainly manifested in:blank forming characteristics ,brick shape and single weight difference.
The siliceous billet is a binder which is bonded and malleable.when molding,the molding pressure should be appropriately increased to increase the density of the silica brick.The molding to increase the silicon density ,the shape of the coke oven silicon brick is complex,the single weight is large ,and the forming thickness can reach 160~600mm,preferably double sided pressing.the methods for forming silicon bricks mainly include mechanical pressing methods,and some large and complex shaped products are formed by vibration molding or air hammer tamping .when the silica brick is fired ,the brick body expands, so the size of the brick mold should be reduced accordingly.
