Experimental study on the effect of CaCl2 solution on the inhibition effect of coal spontaneous combustion

Abstract

In this paper, CaCl2 solution was used as an inhibitor. Raw coal was soaked in CaCl2 solution with a mass concentration of 20%, and inhibited coal samples were prepared at different temperature conditions (30 ℃, 50 ℃, 70 ℃ and 90 ℃) for different periods of time. The inhibition effect of CaCl2 solution on coal spontaneous combustion was studied through temperature programmed tests and infrared spectrum experiments. It was found that the content of surface active groups (−CH3, −CH2, −COOH, −C=O) and coal oxygen consumption rate decreased significantly with the increase of pre-inhibition temperature and pre-inhibition time. The inhibition rate and cross point temperature also increase significantly. The results show that increasing the pre-inhibition temperature and the pre-inhibition time can obviously improve the inhibitory effects on the spontaneous combustion characteristics of coal.

Keywords

• coal spontaneous combustion
• halide salt
• inorganic inhibitor
• pre-inhibition
• inhibition rate
• cross-point temperature