Making sand and gravel aggregate from coal gangue

Coal gangue production building materials

The use of coal gangue to prepare building materials, mainly including bricks, cement raw materials, ceramic materials, etc.

1. Brick making. Coal gangue bricks usually use the calorific value of coal gangue to provide the required drying and baking energy. The calorific value of coal gangue in my country is 3300~6300 kJ/kg[5]. When the calorific value is low, part of coal can be added for production. Therefore, the use of coal gangue to make bricks can significantly reduce energy consumption. At present, the process of making coal gangue bricks in my country is relatively mature, and solid gangue bricks, porous load-bearing gangue bricks and hollow gangue bricks have been developed and produced. Coal gangue brick is made of coal gangue as raw material, mixed with a small amount of clay after being ground, pressed into shape, air-dried and then sent to the kiln for calcination. It weighs about 1400~1650kg per cubic meter.

2. Production of cement from coal gangue. The main components of coal gangue are SiO2 and Al2O3, which are similar in chemical composition to clay and can replace part of clay to produce cement. The crushed coal gangue and lime are mixed in a certain proportion, and then calcined to obtain clinker mainly composed of calcium silicate, which is then ground with gypsum and other materials to obtain cement with high compressive strength.

3. Concrete aggregate made of coal gangue. The use of coal gangue in aggregate usually requires certain heat treatment to remove the carbon and organic matter in the gangue, so as to reduce the weak components in the gangue aggregate, and at the same time make the minerals in it edging, generate active substances to improve the aggregate performance Surface activity.