A Viable Solution for Industrial Waste Ash: Recycling in Fired Clay Bricks

Abstract

The rapid increase in the generation of industrial ash alerted the authorities to seek efficient management of this harmful waste. This research seeks an entirely new use of industry ash to manufacture bricks. While brick is the most prominent construction product worldwide, the brick manufacturing industry cannot deliver the increased demand due to a new challenge: clay shortage. Two different industry waste ash types (IWA 1-CaO rich and IWA 2-SiO2 rich) were tested at different percentages of 10%, 20%, and 30% (by weight) for their suitability in manufacturing bricks. Compressive strength, water absorption, the initial rate of absorption, thermal conductivity test, 3D-CT scanning, scanning electron microscope analysis, x-ray diffraction analysis, x-ray fluorescence analysis, salt-resistance test, and heavy metals leaching test were performed to determine the physical, chemical, mechanical, durability and leachate characteristics of waste reformed bricks and to ascertain the product compliance of the lab prototype. The results indicated that the novel brick product manufactured from industrial waste can be superior to control brick (0% of waste ash) in thermal characteristics and compressive strength while achieving essential compliance requirements satisfying national standards. The thermal conductivity of ash reformed bricks was 40% lower compared to standard bricks when 30% ash is mixed into the composition. In addition, the maximum compressive strength of 72.53 MPa was achieved with the addition of 10% IWA 2 at a firing temperature of 1,050°C. The outcomes from this project could potentially provide a sustainable product for the brick industry, which has exponential demand in the current market, while resolving a growing solid waste catastrophe and clay shortage.