Research Projects

Objective: To develop economical and environmental friendly bricks and pavement blocks with the application of chemically activated kime sludge for replacement of cement.; To develop calcium oxide and calcium carbonate based wall putty with the application of lime sludge and activities.

Summary: The purpose of this study is to utilize paper mill lime sludge (industrial waste) as a replacement material in building products. Hence there should be strong needs to develop materials and technologies that utilize various wastes in an effective and economical context for new product developments in construction industries. So utilization of lime sludge in building materials can also make the proposed hypotheses more important' Lime sludge is generated in the recovery section of the paper industry. Conventionally' lime is recovered from the lime sludge in the paper mill through lime kilns' However it is an energy intensive process in general and specifically in lndian paper mills high silica content poses scaring and other problems during ,.me recovery. A very few mills in lndia are running lime recovery section, many of them are disposing lime sludge through landfilling which is the cause of environmental concern' The proposed development of concrete bricks, pavements and wall putty can be an effective solution for rime sludge utilization and at the same time alternative material to the cement which will decrease the emission of GHG gases The lime sludge will be subjected to chemical treatment using NaOH and fly ash as activator. The approach for proposed study is to convert inert CaCOs of lime sludge into more reactive phase which can be used as a binder. The concentration of NaOH would be 1-2 Molar. Higher concentration may also be used for effective reactivity Calcium oxide and calcium carbonate based putty development from the lime sludge will be another target of this proposal. For calcium oxide based putty, lime sludge will be calcined in electric furnace and adhesive will be added to maintain the plasticity (>2OO Emley units, according to ASTM Cl 10) of paste during the hydration process. lt will produced by adding more water during hydration, approx. 1 part of quick lime to '1-1 4 parts of water by weight will be mixed to produce a moldable mass inform of putty.