As we all know, the ball mill grinder undertakes the grinding operation of the whole concentrator with large investment and high energy consumption, so the concentrator is also very cautious in the selection and use of grinding equipment. Recently, many customers have consulted the daily maintenance of the ball mill grinder in winter due to the sudden drop in air temperature.
The repair and maintenance of the ball mill grinder is a kind of daily work, its work effect directly determines the operation efficiency of the ball mill. The cold climate in winter, the large temperature difference between the equipment in operation and the temperature will lead to different degrees of influence on the use and storage of the ball mill, and may even lead to the temporary stop or stop grinding for a winter, which virtually put forward higher requirements on the daily maintenance of the ball mill grinder.
Use the table of contents below to navigate through the guide:
Compared with other seasons, the ball mill in winter may aggravate the wear, link loosening, metal structure corrosion, resulting in various decreases of technical, economic, and safety performance. In addition, the ball mill operator should also ensure the daily cleaning of the ball mill, and prevent the corrosion, rust, and even blockage and wear of the ball mill due to impurities "freezing".
■ In winter, it is necessary to preheat the ball mill grinder in advance. The winter temperature is low, and the electronic control device of the ball mill generally sets the starting temperature (22°-23°C or so). The ball mill cannot start or work normally without preheating;
■ In winter production, the dry mill should pay attention to exhaust gas and heat preservation work. If it is lower than the dew point, the cooling water will appear and damage the dust collector;
■ Considering the thermal expansion and cold contraction, the ball mill operator need to tighten the screws in the main parts and check the hollow shaft, main bearing, barrel, reducer, gear, and other important parts, then make a good record;
■ Control and inspect the temperature well. In the running process, the lubricating oil temperature of the main bearing shall not exceed 55℃, the temperature of transmission bearing and reducer shall not exceed 55℃, and the upper limit shall not exceed 60℃. Although the outdoor temperature is low in winter, the ball mill grinder will be heated by friction in the operation process, causing the temperature to rise;
■ Check whether there is ore leakage at the bolt connection of ball mill barrel body, barrel body and end cover link, ore feeding trolley, and so on;
■ Monitor the wear condition of steel ball in real-time, timely ensuring the replacement in case of serious wear.
■ If the stop time is long, the three-way cock installed at the water outlet of the main bearing should be transferred to the water discharge position, and the water in the channel of the spherical tile string should be removed by siphon, avoiding the freezing crack of the spherical tile or bearing seat;
■ When the grinding is stopped for a long time, the cooling water needs to be stopped after the temperature of the grinding body is completely reduced to the same as the ambient temperature, and the water in the memory of the spindle tile is blown clean with compressed air;
■ Every 5-10 minutes after stopping, turn the mill half circle and stop it in the opposite position until the mill is fully cooled, which can prevent the deformation of the mill body;
■ The steel ball and material should be poured out in advance, so as to avoid the deformation and bending of the ball mill barrel, and scab into a block of the steel ball and material.
■ Ensure that there is no ash accumulation in the operation room or machine room, and spare parts, materials, and tools are stored neatly.
■ The staff clean the ball mill by shift and once a week;
■ Except for the running part, all platforms should be cleaned in time to avoid dust accumulation.
With the arrival of winter, the temperature decreases, the viscosity of lubricating oil increases, and the fluidity decreases, which greatly affects the lubrication effect of the ball mill.
Due to the large temperature change after shutdown and in the operation, the valve in each startup needs to be adjusted until the oil supply pressure reaches 0.2 ~ 0.4MPa. But with the increase of running time, the lubricating oil temperature increases, the viscosity continues to decline, and the pressure is also reduced. If the valve is not adjusted in time and the pipeline resistance is increased at this time, the continuous low oil supply pressure will cause the thin oil station to alarm and stop grinding. Therefore, it is very important to make sure the lubrication work of the ball mill in winter.
■ Choose the low oil number of lubricating oil, the oil quality is thin and can ensure a better fluidity at low temperature. The high oil number of lubricating oil has a thicker oil quality and poor liquidity. If there is no indoor heating and lubricating oil preheating device, the oil pump station cannot work at all;
■ At the beginning of winter, all lubricating oil in the ball mill should be released after the continuous operation for a month, thoroughly cleaned and replaced with new oil;
■ When starting, refueling or changing the oil in winter, the oil should be heated to about 25°C in advance. If the grinding is stopped for more than 8 hours, the lubricating oil of the main bearing should be released and heated to 20℃ before starting and then poured into the bearing.
■ The large and small gear spray lubrication system is equipped to enhance the lubrication effect, reduce the gear wear, automatically control the oil injection and display the working process, ensuring a stable lubrication state;
■ The lubricating oil that has deteriorated or is not clean cannot be used.
■ It is necessary to filter new lubricating oil before adding the new lubricating oil;
In a harsh environment, the ball mill grinder operators should give priority to prevention, adhere to the combination of daily maintenance and scientific plan maintenance, ensure the good working condition of the ball mill through a "combination of transportation and inspection" and guarantee the economic benefits of concentrator.