Study on Preparation and Properties of Polyvinyl Alcohol Oxygen-insulating Foam Material to Prevent the Coal Spontaneous Combustion

摘要

In order to develop a new material to prevent the spontaneous combustion of coal, the modifiers, coagulant agents and foaming agents were used to modify the polyvinyl alcohol (PVA) which is an excellent oxygen-insulating material. Then the oxygen-insulating characteristics and the stability of the PVA foam material were investigated. The results show that the 3# foaming agent performs well at 0. 04% (wt%), when the liquid precipitation half-life reaches up to 395 seconds in the half-life experiment. And when 1% (wt%) modifier A is added, the foam presents a good state. The optimum formulation of foam material (wt%) is 94. 81% water, 4% PVA, 1% modifier A, 0.15% coagulant agent B and 0.04% foaming agent. Simulated coal pile storage conditions, the oxygen-insulating characteristics and the stability of the PVA foam material have been investigated for 40 days. The oxygen concentration in coal pile could be decreased from 21% to 5% . The rate of coal oxidation and self-heating is weakened. After 40 days, the PVA foam material remains a good condition, nearly as well as before the experiment. So the PVA oxygen-insulating foam material can completely meet the requirements to prevent the spontaneous combustion of coal, it will have a good prospect.