High Alumina Cement

• High alumina cement is obtained by fusing or sintering a mixture, in suitable proportions, of alumina and calcareous materials and grinding the resultant product to a fine powder. The raw materials used for the manufacture of high alumina cement are limestone and bauxite.
• These raw materials with the required proportion of coke were charged into the furnace. The furnace is fired with pulverised coal or oil with a hot air blast. The fusion takes place at a temperature of about 1550-1600°C. The cement is maintained in a liquid state in the furnace. Afterwards the molten cement is run into moulds and cooled. These castings are known as pigs. After cooling the cement mass resembles a dark, fine gey compact rock resembling the structure and hardeness of basalt rock.
• The pigs of fused cement, after cooling are crushed and then ground in tube mills to a finess of about 3000 sq. cm/gm.