The loading system of wear-resistant materials mainly refers to the effect of factors such as the shape and size of wear-resistant materials, filling rate, suitable ratio, and reasonable addition on the production efficiency of grinding machines.
Firstly, the shape and material of wear-resistant materials
For a long time, people have been accustomed to using wear-resistant materials in the shape of round balls or long rods. The former grinding method is point to point contact, suitable for fine grinding, while the latter grinding method is line to line contact, suitable for rough grinding, but the grinding efficiency is higher than the former. In recent years, people have designed a medium shape called baseball, which has a higher grinding efficiency than a round ball but is second to a rod and has a wider range of applications than balls and rods. Its grinding method has the characteristics of point, line, and surface contact, and can be used for coarse, medium, and fine grinding.
The selection of materials should consider factors such as the specific gravity, hardness, wear resistance, price, and difficulty in processing and manufacturing of wear-resistant materials. China has long used steel balls and cast iron balls. The specific gravity of steel balls is large, and their impact and grinding effects are much better than those of iron balls of the same size. At the same time, due to the large specific gravity, the size of the balls can be correspondingly reduced and increased, thereby increasing the number of strikes on the ore per unit time. In addition, the high density medium has a low filling rate, which increases the effective volume of loaded materials, can increase the feeding amount, and increase the productivity of the grinding machine. But the processing of steel balls is complicated, and the price is 40-50% higher than that of cast iron balls.
Secondly, the appropriate ratio of wear-resistant materials
In production, ball mills are equipped with balls of various diameters to process materials composed of ore particles of different sizes. In theory, only by ensuring that the weight ratio of various balls is suitable for the particle size composition of the ground material can good grinding results be achieved. Due to the constant changes in the particle size composition of the ground material and the size of the medium during the grinding process, it is impossible to require the ball ratio to be absolutely compatible with the particle size composition of the ground material. The beneficiation plant strives to promote the medium to be in a suitable ratio through the initial ball loading of the grinding machine and continuous reasonable ball filling, in order to improve the grinding effect.
Thirdly, the loading amount and ball load filling rate of wear-resistant materials
When the speed rate of the grinding machine is high, the amount of balls loaded should be less. Conversely, when the speed rate of the grinding machine is low, the amount of balls loaded should be more. Under the premise of a certain rotational speed, it is necessary to find the appropriate ball loading amount and strive to maintain stability in production to improve grinding efficiency. Experimental results have shown that when the rotational speed of the ball mill is between 80-85%, it is advisable to set a medium filling rate of 40-50%; Under the condition of high-speed grinding (with a speed rate of 100-120%), the filling rate of wear-resistant materials should be reduced to around 35-40%. The filling rate of a rod mill is lower than that of a ball mill, generally ranging from 35% to 45%.
Fourthly, the size of wear-resistant materials
The size of wear-resistant materials mainly depends on the physical and mechanical properties and particle size composition of the ore. When processing ores with high hardness and coarse particle size, a larger impact force is required, so larger balls should be loaded. When the ore is soft and the feed particle size is not very large, and it is required that the grinding product has a finer particle size, grinding force should be the main method, and smaller balls (with a large surface area and strong grinding effect) can be loaded.
扫一扫
