With the rapid development of China's economy, the demand for energy is increasing, which promotes the development of many industries such as coal mining and construction. In the process of coal mining, the support and protection of the roadway roof is the premise to ensure the safe and efficient production of coal mines. Chemical grouting is a technology developed in recent years, which can consolidate the broken coal and rock mass in a short time and achieve high strength, effectively improve the stability of the broken coal and rock mass in the mining process, and avoid and reduce the roof and sheet gang accidents caused by the crushing surrounding rock.

The performance of the grouting material determines the quality of roof reinforcement, polyurethane materials are widely used in the reinforcement of broken coal and rock mass, the plugging of roadway roof water inrush and other fields with the advantages of moderate viscosity, controllable curing time, and good toughness and strength of the consolidated body, and have broad application prospects.

Polyurethane rigid foam is usually used in coal mine reinforcement technology, and its raw materials are divided into white and black materials. The white material is a mixture of polyether polyols and additives, and the black material is isocyanate. When in use, the same volume of black and white material is pressed into the crushed coal rock mass with a grouting pump, and a series of complex chemical reactions begin to occur after full mixing, followed by cross-linking and solidification.

In a humid environment, the polyurethane slurry reacts with water to generate CO2 after being injected into the ground, which generates a large internal pressure without overflowing, promotes the deep diffusion of the slurry to the cracks and pores, and squeezes the slurry to form a strong bond with the surrounding interface, thereby blocking the leakage channel and improving the strength of the formation.

Finally, the consolidated body expands, penetrates and fills the entire fracture surface in the broken coal and rock body to form a network skeleton structure, which binds the loose coal and rock mass into a whole, improves the overall strength and toughness of the coal and rock mass, and achieves the reinforcement effect on the coal and rock mass.

Qichen is a manufacturer specializing in the production of Blended Polyols for Polyurethane rigid foam system and has been contributing to the development of the polymer grouting material for colliery industry.