Study of resource utilization and fire prevention characteristics of a novel gel formulated from coal mine sludge (MS)

Abstract

In order to utilize coal mine sludge (MS) and reduce material cost, this paper reports the preparation method of a novel MS/CMC-Al3+ fire prevention and extinguishing material by mixing MS with sodium carboxymethyl cellulose (CMC), polyaluminium chloride, and citric acid. The experimental results indicate that with MS: CMC: AlCit (aluminum citrate): H2O = 15:1:4:35, MS/CMC-Al3+ gel displayed the best compressive strength and inhibitory effect. The combination of Raman spectroscopy and FTIR spectroscopy showed that HPAM-Al3+/Fe3+ gel in MS and CMC form a strong chelation force between ions. SEM analysis showed that the surface structure of MS/CMC-Al3+ gel was extremely dense and MS, CMC, Al3+, and Fe3+ were evenly distributed in the composite colloid, suggesting that HPAM-Al3+/Fe3+ gel and CMC were completely crosslinked. By analyzing the oxidation characteristics of MS/CMC-Al3+ gel via TG-IR, it was found that MS/CMC-Al3+ gel can effectively inhibit the increase in coal temperature and heat accumulation, which is beneficial for spontaneous combustion process of coal. Simultaneously, MS/CMC-Al3+ gel can also inhibit the generation of CO and CO2 from combustion, which plays a significant inhibitory role. MS/CMC-Al3+ gel reduces pollution and cost by the recycling of wastes; hence, it is a clean fire protection and extinguishing material.