At present, quite a few coal mines in China still use U-type mine car. Due to the wet and frozen stickiness of pulverized coal at high water content, it brings great difficulties to production, and becomes one of the major technical problems puzzling industrial and mining production. According to incomplete statistics, the average coal sticking rate of coal mining vehicles in coal mines is about 15%, and the economic loss caused by wet sticking alone amounts to 400 million yuan per year. The relevant departments in China have conducted on-site investigations on the "bottom sticking" situation of nearly 500 U-type mine car in 12 mines. The investigation results show that for water mining or rainy season mining, the coal adhesion rate of tramcars varies from 5% to 40% depending on the coal quality and working conditions. In winter, the average outdoor temperature in northern China is 15 to 30 ℃, and the coal sticking rate of mining cars and other coal transporting vehicles reaches 3O to 60%. This greatly reduces production efficiency.
In addition to the above, the adhesion and corrosion of the mining car coexist with each other. On the one hand, corrosion greatly reduces the service life of the mining car, and on the other hand, due to corrosion, the inner wall of the car becomes rough, making it easier to produce adhesion and accumulation of the bottom. Sticky and accumulated bottoms not only occupy an effective volume of 30 to 5O, but also are extremely prone to severe crevice corrosion, accelerating the damage rate of tramcars. Therefore, it is of great significance to study the mechanism of wet adhesion of coal and seek effective technology for reducing adhesion and coal removal.
Today, let's take a look at the causes of wet adhesion.
Main reasons for adhesion of mine car:
The first is relatively soft coal, with a high pulverized coal rate and a colloidal shape when encountering water;
The second is that the cavity layer of fat coal and coking coal is thick and easy to bond when encountering water;
The third is the coal mine excavation gangue, which contains a lot of powder;
The fourth is the dirty and miscellaneous coal washed out from the bottom of the well and cleaned from the water sump, which has a high content of pulverized coal and is prone to coal-water mixing and coalescence;
The fifth is to use mining trucks to transport cement, or even manually mix materials (such as cement) inside the truck.
In addition, the adhesion of the mine car is also related to the smoothness of the interior of the tramcar and the shape of the bottom of the mine car. Generally, when the inner wall is relatively smooth, it is relatively difficult to adhere to the bottom. U-shaped tramcars are most likely to adhere to the bottom, while the bottom accumulation situation of tramcars with convex and flat bottoms has significantly improved.
From the above, we can see the causes of wet adhesion. If everyone pays more attention to such causes and tries to minimize or avoid the above situations, we believe that the efficiency of coal mine production will be greatly improved. I hope today's content will be helpful to everyone.
