Influencing factors of power consumption in grinding iron ore with diamond cutter head

Abstract

ObjectivesThe existing mining equipments, such as coal mining machines, excavators, tunneling machines, and diamond tools, are combined to form a new mining equipment called the“grinding mining machine”, which is used for grinding mining. The main advantage of grinding mining applied in metal mines is that it greatly simplifies the mining process. However, whether it can be popularized and applied depends on whether its operating cost is close to or lower than the mining cost of drilling and blasting methods. Among these, the energy consumption cost of grinding mining machine operation is one of the most critical control indicators. The existing cutter heads of diamond tools, such as diamond circular saw blades and diamond grinding wheels, are used to grind iron ore. The relationship between grinding power consumption and the type of diamond cutter heads, the rock characteristics of iron ore, and the grinding operation parameters are studied. The factors affecting the grinding efficiency and the cost of the grinding mining machine are explored to find a reasonable range of values that can adapt to different situations.MethodsAn experimental platform was built, and two types of diamond circular saw blades and two types of diamond grinding wheels were used to conduct grinding experiments on two types of iron ore samples. There were a total of six experimental schemes, and power consumption experimental data were obtained for different blade heads and their grinding line speeds, grinding thicknesses, grinding widths, grinding movement rates, etc. Based on this, the rated grinding efficiency, the rated motor power consumption, and the rated grinding power consumption were calculated. The main influencing factors of power consumption in grinding iron ores with diamond cutter heads were analyzed by comparing the above data.ResultsAccording to the experimental data and the calculation analysis of the six experimental schemes, the following results were obtained: (1) The average rated motor power consumption of the magnetic iron zone of ore 1, the quartz zone, and the magnetic iron zone of ore 2 are 50.41, 36.05, and 15.17 (kW·h)/t, respectively. This indicates that the rock characteristics of ore, such as uniaxial compressive strength, quartz content, and particle size, have a significant impact on power consumption during grinding. The higher the uniaxial compressive strength of the ore, the higher the quartz content and the smaller the quartz particle size, the higher the power consumption of grinding the ore. (2) Two different types of diamond circular saw blades and two types of diamond grinding wheels were used to conduct grinding experiments on two different iron ore samples. Compared with other types of diamond heads, the use of sharp diamond heads with added iron sheets can significantly reduce power consumption during ore grinding operations. (3) Under the condition of constant rated power of the main motor, the grinding efficiency of the grinding wheel can be improved, and the power consumption of the motor can be reduced by optimizing the width and the diameter of the grinding wheel. (4) The single grinding movement distance Δs is closely related to grinding efficiency and directly related to the diamond cutting depth Δh. When the Δs value ranges from 6.01 to 14.35, 3.23 to 9.96, 4.14 to 15.04, 26.44 to 32.09, 1.62 to 5.37, and 2.02 to 5.64 μm in the six experimental schemes of M1 to M6, the grinding power consumption can be effectively reduced by adjusting the Δs value. When the Δs values of M1 to M6 are 14.35, 6.65, 15.04, 32.09, 5.37, and 3.22 μm, respectively, the grinding power consumption is the lowest. However, to determine the most suitable Δs value, it is necessary to comprehensively consider factors such as the size and the structure of the diamond tool, the performance of the cutting head, the characteristics of the ore rock, the operating parameters, and the force situation of the cutting head, in order to find a reasonable range of values that can adapt to different situations. Additionally, according to the force analysis of the diamond cutter head grinding ore and the phenomena observed in the experiment, selecting the appropriate grinding movement direction is conducive to pulp collection and maximizes the gain effect of tangential pushing on the cutting force.ConclusionsThe energy consumption of diamond cutter heads grinding ores should be optimized in two aspects: the manufacturing technology and the use parameters of the cutter heads. In terms of diamond cutter head manufacturing technology, optimization should be carried out from the aspects of diamond grade, diamond particle size, and matrix compositions, formula, processing technology, as well as the size design, shape and arrangement of diamond cutting heads. Cutting heads that are both sharp and durable for grinding different types of ores should be developed to reduce energy consumption and operating costs. In terms of using operational parameters, further optimization research should be conducted on grinding size parameters and dynamic parameters to improve grinding efficiency, reduce grinding energy consumption and operational costs, and provide experimental and theoretical basis for the manufacturing of grinding and mining machines. The core technology of the grinding mining machine lies in the manufacturing technology of the grinding drum, and optimizing diamond cutter head grinding ores is fundamental to improving the grinding drum manufacturing technology.

Keywords

• grinding and mining machine
• diamond saw blade
• diamond grinding wheel
• grinding efficiency
• grinding power consumption