Coke and Coke breeze. These wastes are in the coal mines and steel mills. A promising way of recycling - briquetting in domestic and industrial fuel briquettes for high-power rotary presses (briquette size 70x70x40mm). Briquettes can be sold to the public and metallurgical plants.
The briquettes are made in a formation machine for concrete products whereby the briquettes are shaped as cubes having an edge of about 8 cm . The wet cubes are stored for 12 days, whereupon they are dried for 24 hours and at a temperature of 60° C. The pressure strength of the briquettes in cold state is measured to 2,639 kPa (26.9 kg/cm 2 ), which value is an average value of six briquettes.
For making it possible to check the heat strength of the briquettes they are subjected to a temperature of 900° C. for one hour, whereupon they were allowed to cool for 24 hours before the heat strength was measured. A value of 2,246 kPa (22.9 kg/cm 2 ) was obtained, which value is an average value for six briquettes.
Briquettes having the above identified composition have a pressure strength in cold state which is slightly less than the above mentioned recommended value of about 2,943 kPa (30 kg/cm 2 ), whereas the heat stength is substantially higher than the above mentioned recommended value of 981 kPa (10 kg/cm 2 ). In the following tables A and B an additional number of examples are given for different mixtures for the manufacture of briquettes, whereby the tables give information about composition, pressure strength, heat strength, evaluation of the strength and observations:
Claims: 1. A briquette suitable for use as an auxiliary fuel in a shaft furnace for melting of mineral in the manufacture of mineral wool comprising:
(a) 30-75% by weight, based on the dry weight of the briquettes, of particles of coke fines or coal fines or both, said fines consisting essentially of particles having a particle size of from 2 to 25 mm ;
(b) at least 7% by weight, based on the dry weight of the briquette, of a hydraulic binder;
(c) at least 15% by weight, based on the dry weight of the briquette, of a fine grain oxidic mineral component selected from the group consisting of sand, slag, stone powder, fly ash, limestone powder, dolomite powder, silicon dioxide, and waste material from mineral wool manufacturer, said fine grain oxidic mineral component having a particle size of less than 2 mm . 2. A briquette according to claim 1 wherein component (a) comprises a mixture of coal and coke particles, the amount of coal particles being 10-50% by weight of the mixture.
3. A briquette according to claim 1 wherein compound (b) comprises cement in an amount of 8-35% by weight, based on the dry weight of the briquette.
4. A briquette according to claim 1 wherein component (c) is present in an amount of up to 35% by weight, based on the dry weight of the briquette.
5. A briquette according to claim 1 wherein said minimum particle size of component (a) is 5 mm .