Preparation and resource utilization of sludge-based fire-preventive and extinguishing composite gel for coal mine. Issue 2 (April 2023)

• Record Type: Journal Article
• Authors: Ma, Weixiang; Ma, Qihua; Zhao, Yanyun; Hu, Xiangming; He, Zhenglong; Chi, Lihui; Zhao, Xiaoxiao; Zhao, Yuxin; Sun, Feng; Chu, Chunyan
• Is Part Of: Journal of environmental chemical engineering. Volume 11:Issue 2(2023)
• Publication Date: 2023-04
• Subjects: Sludge -- Gel -- Orthogonal test -- Fire prevention and extinguishing -- Resource utilization; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2023.109465
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: We prepared a sludge-based fire-preventive and extinguishing composite gel for coal mines using sludge, HPAM, water glass, and sodium bicarbonate as the main raw materials. Orthogonal test was used to analyze the effects of each component and its level on the performance of gel to determine the optimal ratio of gel and then tested its fire-preventive and extinguishing characteristics. Finally, the gelling mechanisms of the gel are discussed. The composite gel prepared at the optimal level showed that the gelling time can be maintained at about 55 s, the water retention can reach up to 58.6% in 12 h at 100 °C. The gel has a dense microstructure and uniform pores, and has the best inhibition rate of coal spontaneous combustion. As compared with other materials, the coal piled with gel did not reignite. TGA showed that the gel hinders oxidation and complete combustion of coal. The in-situ infrared analysis confirmed that the coal sample treated with gel has a low content of aliphatic hydrocarbon and hydroxyl group. Infrared spectroscopy analysis indicated that the sludge in the gel plays the role of filler. The organic-inorganic composite network structure formed by the sludge and the gel not only prevents the system from water loss and coal oxidation but also absorbs a large amount of sludge and realizes the resource utilization of sludge. Therefore, the preparation of composite gel reduces the secondary pollution of sludge and lowers the cost of the material, making it an economical and environmentally friendly fire-preventive and extinguishing material. Graphical Abstract: ga1 Highlights: Prepared a sludge-based composite gel with high-efficiency fire preventive and extinguishing performance. HPAM can significantly enhance the thickening of sludge suspension and the water retention capacity of the composite gel. Explained the formation mechanism of organic-inorganic complex network structure in the sludge-based composite gel.