Recycling of spent industrial soil in manufacturing process of clay brick

Abstract

The present study aimed to investigate the feasibility of using Spent Industrial Soil (SIS) generated in the process of Aromatics production in manufacturing clay brick. The physicochemical properties of raw clay and SIS were analyzed using different lab tests such as X-ray Fluorescence (XRF) and X-ray diffraction (XRD). Six different amounts of SIS (i.e. 0, 5, 10, 15, 20 and 25 % by weight) were mixed with clay soil and fired by electric furnaces at 950 °C for 8 h to make fired brick samples. Magnified images were taken using Scanning Electron Microscope (SEM) for all samples to indicate the significant changes in pores size due to adding SIS. The results showed that SIS increases the water absorption and water suction and reduces the density of brick samples due to increasing porosity in the structure of brick. Also the linear shrinkage is reduced in samples containing SIS and this finding is justified by the lower amounts of hydrophilic elements (i.e. Ca, Mn, and Mg) in SIS, compared with raw clay soil. On the other hand, the compressive strength of brick samples which is affected by both porosity and SiO2 amount has been increased by mixing SIS content of 20 %. Thus using SIS in clay brick construction is an effective way to make a porous and lighter brick which meets the required standards of structural and environmental issues.