| 摘要 |
A method of producing a lightweight aggregate for the building industry, whereby, in the first phase, coal-associated shales from wastes produced during coal mining and cleaning, are crushed; in the second phase, water is added to the crushed material and the material is ground; in the third phase, this material is heated in a rotary furnace working in counter-current, in which it passes through, subsequently, the drying zone, the zone of sintering at the temperature of 900-1150 degrees Celsius, the zone of cooling at the temperature below 1150 degrees Celsius; in the fourth phase, the finished product is classified. The gases produced in the rotary furnace, without separation or after separation of the dusty fraction, with the possibility of re-circulating to the rotary furnace as a charge material, are carried away to the emitter. It is characterised in that in the first phase, 4-15 parts by weight of coal are added per 100 parts by weight of these coal-associated shales, following earlier measurement of the coal content in them, then the material is crushed to granules not bigger than 50 mm. In the second phase, water is added in the amount of 30-40 percent of the crushed shales and coal mix, further it is wet ground to produce granules not larger than 1.0 mm, coal content in the sludge produced in such a manner is measured again, and any possible coal shortages are supplemented with coal granules not bigger than 1.0 mm to the amount after the first phase. In the third phase, the sludge is dried in the rotary furnace at the temperature of 20-700 degrees Celsius, where, in the first phase of the drying process, at the temperature of up to 120 degrees Celsius, water and later chemically combined water at 250-700 degrees Celsius from the decomposition of aluminosilicates contained in the charge are evaporated, and the aggregate is cooled from 1150 degrees Celsius to 200 degrees Celsius. In the fourth phase, the produced granules are classified according to their sizes and purpose. |
