Cement Energy and Environment

Table2Break-up in thermal energy conservation from measures introduced S.No. I I. II. ... Ill. iv. v. vi. vii. I 175 c 165 _Q 155 ~;: 145 "' (1) "' E 135 c (1) 8o 125 ~o ~~ 115 ~:c 105 ~~ 0 95 (1) a. 85 (/) 75 Modification/measure introduced Modification in kiln chain system Instal_fation of bag j ~ 114r. 0-CtL'>lm.iJL;.~.tit Optimisation of Pillard burner operation Use of heat insulating bricks Use of high - calorific value coal Optimisation of air flow for improving secondary air temperature Use of slurry thinner Total Thermal Energy Saving 95 97 91-92 92-93 93-94 94-95 95-96 96-97 97-98 98-99 Year Fig. 1 Specific Power Consumption Courtesy : Shriram Cement Works ·- Reduction in Remarks specific heat consumption kcal/kg of clinker 80 Present specific heat consumption is 1280 kcallkg clinker 26 -· I - --=... ,.__ -- 5 5 LO 40 166 0.305 .-------------------, c 0.290 0 ~- 0.285 "' c "' Q) g ~ ~ () 0.265 ~0 Ot::: ,gl- ·g 0.245 a. (/) 0.225 +---r---.---...---r----.--.---~----i 91-92 92-93 93-94 94-95 95·96 96-97 97-98 98-99 Year Fig. 2 Specific Coal Consumption Feature of the Quarter REACTIVE BELITE CEMENT- A TECHNOLOGY FULL OF PROMISE FOR BETTER RESOURCE UTILISATION C ement manufacturers and entrepreneurs are often perplexed with the vexed question of using lower grade limestones. For many operating captive limestone mines, depletion of the "creamy layers " from prolonged exploitation leaves marginal grade I imestonc, which needs appropriate type of "sweeteners" for use. ln fact, most of the plants closed down in the second half of last century (e.g., Rohtas and Asoka, ACC-Suraj pur, Jai pur Udyog Ltd., Bhadrawati iron and Steel, etc.,) owe their demise to depletion of cement grade limestone reserve. . As a matter of fact. a large number of operating plants are facing acute shortage of good quality limestone in their quan-ies for 6 manufacturing cement of marketab le grade. Minin g engineers and cement technologists had always been looking for a sui table technology to make lower grade limestones usable for prolonging the life of mi nes and plants. However, several alternati ves attempted so f~u· could not provide any lasting remedy. 'lew Techuolug~ Recently. ACC's Research and Consultancy Directorate (RCD) has developed a proces technology for utilising marginal grade li mestones with high silica content. The 1