A novel biomass sodium alginate gel foam to inhibit the spontaneous combustion of coal

In order to address the environmentally friendly issue of fire prevention and extinguishing materials in coal mines, A new biomass sodium alginate gel foam (SC-GF) was prepared by using sodium alginate (SA), calcium L-lactate (CL), alkyl glycoside (APG) and tea saponin (TS). The effect of different concentrations of CL on the properties of SC-GF was analyzed by studying the gelation time, foaming volume and half-life of the SC-GF. The results show that the gelation time of SC-GF is successfully controlled by using the weak electrolyte CL as the cross-linking agent. When SA: CL: APG: TS = 4 : 1 : 2 : 1, the gelation time of SC-GF is 10 min with half-life of 16 days. Furthermore, A metal coordination bond favorable to the stability of SC-GF is formed by the carboxylate ion of α-L-gulonic acid in SA and Ca2+ ionized by CL. SC-GF exhibits excellent fire prevention and extinguishing properties. The CO concentration of the coal sample treated with SC-GF decreases from 7556.8 to 34.92 ppm in the process of oxidation at room temperature for 48 h. The temperature-programmed oxidation test shows that SC-GF can delay the accelerated oxidation temperature from 120 to 160 °C, and the CO inhibition rate is as high as 60.5 % at 200 °C. The fire extinguishing test indicates that SC-GF can significantly reduce the temperature of the coal sample and extinguish the coal fire quickly. The study is useful to develop efficient and environmentally friendly coal mine fire prevention and extinguishing materials.