PADDY HUSK AS RAW-MATERIAL AND FUEL FOR MAKING PORTLAND-CEMENT

Paddy husk has been finding world wide attention for its utilization i n various applications. Most of the research in this area, particularl y in the field of cement and building materials has been carried out i n the development of lime-rice husk ash cementitious materials. Howeve r, the strengths of these cements are low. The present paper deals wit h the utilization of both calorific value and reactive silica of paddy husk for producing Portland cement type clinkers. The physico-chemica l and minerological properties of the clinkers and cements produced ar e presented. The burnability of the raw mixes containing husk as fuel is found to be better than those prepared with other fuels following t he same process. This is attributed to the high reactivity of the insi tu generated silica in the ash and rapid burning and cooling schedule maintained in the process of clinkerisation. Cements of various techno logical properties comparable to ordinary Portland cement can be produ ced using paddy husk as fuel at a significantly low LSF and low temper ature of around 1300 deg.C. The clinkers generated are soft and porous and the fuel also being a waste material, the cement produced is expe cted to be of low cost.