The main difference in the production of silica brick is the way to prepare lime-sand mixture, and isolated drum silo way. We give a brief description of each of these ways: Drum way: essence of this method is as follows: sand and fine ground lime, obtained by grinding in a ball mill, lump lime, arrive in separate bunkers over gasilnym drum. From the bunker sand and lime periodically loaded into the drum gasilny. And the sand is dosed by volume, and lime – by weight. Gasilny drum hermetically closed and steam under pressure 0.15-0.2 MPa occurs when lime is continuously a rotating drum.
The process of slaked lime lasts 40 minutes. Silo way: pre-mixed and moistened with a lot of direct to absorb into silos. Here it should be noted that the process of extinction in the last bins 7.12 h, ie 10 – 15 times longer than the drums, which undoubtedly is a significant drawback silos ways. After the extinction phase of lime-sand mixture enters the blade agitator or runners, where it is further moistened and stirred, and then sent further to the weight pressing. Density and strength of brick is provided by mechanical compaction pressure of 15 20 MPa. Raw, molded bricks are laid on truck, which is directed into an autoclave for curing. The shape of the autoclave is a cylinder with a diameter of two meters long and 20 m, with the ends of the autoclave lid.
As you know, when the temperature accelerates the reaction between lime and sand, and at a temperature of 174 C, it takes at least 8-10 h. Fast-curing takes place not only at high temperatures, high humidity, but for this to let steam autoclave pressure to 0.8 MPa and this pressure is kept 6-8 hours of steam pressure is raised and reduced over 1.5 hours steaming cycle lasts 10-14 hours silicate brick manufacture size 250X120x65 mm; brands – M75, 100, 125, 150 and 200, water absorption – 8-16%, thermal conductivity – 0,70-0,75 W / m – C with a weight – 1800-1900 kg/m3, ie, slightly higher than that of clay bricks, frost SSE 15. Heat-insulating qualities of the walls of silica brick and clay is almost equal. silicate brick