Potential recycling of metallurgical slag waste into geopolymer products: A brief review

Abstract

Steel manufacturing process may produce waste such as slag, sludge, dust and mill scale. Since it is an unavoidable waste, the abundance of their production is becoming an environmental concern regarding the high rise of solid waste from the industry. There has been some well-known utilization of slag usage in the industry in handling the waste such as in road construction, cementing material as well as sorbent material. These past years had witnessed the evergrowing interest in the slag incorporation into geopolymer product due to their flexibility of the raw material range that makes incorporation of metallurgical slag waste possible. Thus, this paper seeks to review about the utilization of metallurgical slag waste into geopolymer product. The review focusing on the methodology, chemistry and the resulting properties of the geopolymers. Therefore, the paper will highlight on the characterizations of both raw materials and final product in terms of their microstructural, crystalline phase present and functional groups. Moreover, factors affecting the final product properties such as the alkali concentration, type of alkali, curing temperature, weight ratio and other factors that are mostly discussed by previous researchers are also critically reviewed.