Submitted by: Kerman Cement Industrial Group (KCIG)
Implemented country: Iran, Islamic Republic of
Title: Utilization of the Zarand coal washery improves the cement manufacturing process from alternative fuels and raw materials
More than 300000 tons of refuse are generated from coal washing operations each year in Zarand, a small city near Kerman,.Over years of accumulation, more than 10 millions tons of coal rejects are landfilled and have not found a beneficial reuse. Rejects typically contain residual coal than can emit significant fuel value. Utilization of Zarand coal washery plant rejects in cement manufacturing process as alternative fuel and raw materials has been studied by KCIG R&D department and Kerman Technical university. The Aim is The procedure of using this intrinsic coal content as a fuel supplement in the energy- intensive process of cement manufacturing potentially leading to the multiple benefits of natural resources and energy conservation, waste recycling, and reducing local environmental effects.
Rejects from coal enrichment process has significant environmental effects through dust emission to the air and heavy metal elements penetration to the soil and underground aquifers. Some of these dangerous metal elements are Chrome (Cr), Arsenic (As), and Mercury (Hg). This reject contains about 30% unburned carbon and volatile organic matters with a remarkable heat value (almost 2,200 Kcal/Kg). Besides, the ash of coal washery reject which has a chemical composition similar to cement raw materials (clay and silica) can be a suitable partial alternative material. Since sintering temperature in cement manufacturing is about 1450°C, the whole heavy metal compounds in the reject are imprisoned in the clinker crystal phases and their environmental disadvantages are completely omitted. The reject usage is limited to particular types of cement.