Preparation and Application of Geopolymer Binders from Industrial Waste

The effective recycling of industrial waste is a globally significant issue. In this study, a geopolymer binder was synthesized using an alkaline activator derived from brown coal gangue and blast furnace slag, along with silica fume as an industrial waste material. Also, the properties of these geopolymer binders are examined using them as a briquette binder. At temperatures above 700°C, roasted brown coal gangue is more active than the initial state. The optimum dosage of alkaline activator is 10M NaOH, silica fume/NaOH ratio of 3, specific gravity of 1.42, and the addition of binder of 6%. The main polymerization products of the alkali activated brown coal gangue geopolymer samples are N-A-S-H gel and amorphous aluminosilicate gel, while the main polymerization products of the alkali activated brown coal gangue -blast furnace slag geopolymer samples are N-A-S-H gel, C-(A)-S-H gel and amorphous aluminosilicate gel. Blast furnace slag is added during the preparation of briquette binder by brown coal gangue geopolymer, which increase the mechanical strength of the geopolymer binder and the optimum dosage is 30%. This study demonstrates a high-value and sustainable pathway for co-utilizing multiple industrial by-products.