Sustainable management of basalt in clay brick industry after its application in heavy metals removal

Abstract

This laboratory study aims to evaluate the removal capabilities of basalt quarry waste (BW) for heavy metals from industrial wastewater and the reuse of contaminated basalt in clay brick industry. The replacement percentages of sand by contaminated basalt were 0, 5, 10 and 20 wt%. The lab made cylinders of different mixes were fired at 800 °C and 850 °C (5 °C/min and 2 h as a holding time) then after were tested and the results were evaluated according to the Egyptian Code (204–2014). The results indicated that the use of BW could be in principle very convenient for the treatment of contaminated industrial wastewater in both economic and environmental terms. The tested properties for the fired briquettes of different mixes achieved the acceptable limits of the Egyptian Code. Also, the physico-mechanical results showed that the incorporation of basalt quarry waste to the clay-based mixes up to 20% fired at 800°C and up to 10% at 850°C are capable to improve the physical and mechanical properties of the fired briquettes to be successfully used as non-load bearing walls. Furthermore, diopside phase is played an important role in the cracking of briquettes due to its thermal expansion characteristics found at 850°C. In addition, it was found that the firing process acts as immobilizer for the studied heavy metals particularly at 800 °C, which is environmentally very beneficial.

Keywords

• Basalt quarry waste
• Heavy metals
• Clay-based mixes
• Walls construction
• Properties