Utilization of sludge in manufacturing Energy Efficient Bricks

Abstract

The bricks are obtained by moulding clay in rectangular blocks of uniform size and then by drying and burning these blocks. Burnt clay bricks have good resistance to moisture, insects and erosion and create a good room environment. They are medium in cost and have medium to high compressive strength. In brick making the major input is fuel followed by labour. Bricks manufactured from dried sludge collected from textile wastewater treatment plant were investigated. Results of tests indicated that the sludge proportion and the firing temperature were the two key factors determining the brick quality. Results showed that the brick weight loss on ignition was mainly attributed to the organic matter content in the sludge being burnt off during the firing process. With up to 6.66% sludge added to the bricks, the strength measured at temperatures 500 0 C met the requirements of the National Standards. This study showed that the pulverized sludge could be used as a brick material in reducing the firing temperature for the production of energy efficient bricks. The bonding strength can be further enhanced by controlling operating conditions.