Innovative Process in Manufacture of Cold Setting Building Brick From Mining and Industrial Wastes

摘要

During mining and industrial processing of different raw materials, a lot of unutilized materials are generated which are discarded as solid wastes. Disposal of these materials not only occupies the valuable land but also causes environmental pollution. At present, the building materials industry is a fast growing sector, where a large quantity of natural resources is being used to meet the requirement. Utilization of waste materials generating from mining and industrial process in making building materials has been paid more attention to conserve the natural resources and minimize the environmental pollution. Manufacture of building bricks without burning of solid fuel is one of the options for utilization of these waste and reduction of CO_2 emission. A considerable research is being persuaded at IMMT, Bhubaneswar to establish alternative methods of non-firing processes in making building materials. Innovative and sustainable processes such as mineral polymerization and mineral cementation have been developed for manufacture of cold setting building bricks to utilize these industrial wastes. Mineral polymerization is a path of chemical reaction in alkaline condition to formulate hydrous chain alumino-silicates phases which on curing in atmospheric temperature ranging 20-35℃ and hot air temperature below 100℃ develops binding strength. The waste materials containing mostly silica, alumina and lime are suitable for mineral polymerization reaction in making building products having crushing strength 60 to 400 kg/cm~2. In this process the alumina silica bearing material such as fly ash and B.F. slag is used 90-95% in manufacture of building brick and block. Mineral cementation is a multi component reaction process that forms hydrous minerals phases similar to hydraulic cement. The waste materials containing hydraulic reaction in presence of water. This process is suitable for all kinds of industrial wastes and tailings to formulate the building products. Performance and properties of the new innovative process adopted in manufacture of cold setting building bricks and blocks from different wastes such as fly ash, red mud, beneficiated iron ore tailings, gypsum, slag etc have been discussed.