As we all know, the ball mill undertakes the important task of grinding operation in the whole concentrator, with large investment and high energy consumption, so each concentrator is also very cautious in the selection and use of grinding equipment. Recently, the temperature dropped sharply and the cold air will attack again. Many customers came to consult about the daily maintenance and maintenance of the ball mill in winter.
The maintenance and repair of ball mill is a daily work, and its working effect directly determines the operation efficiency of ball mill. The cold climate in winter and the large temperature difference between the equipment and the air temperature during operation (one cold and one hot) will cause the ball mill to be affected to varying degrees in the process of use and storage, and may even cause the mill to be stopped temporarily or for a winter, which virtually puts forward higher requirements for the daily maintenance and maintenance of the ball mill.
Ensure daily inspection and cleaning of ball mill
Compared with other seasons, the ball mill may aggravate the problems of wear, loose links and metal structure corrosion in winter, resulting in the reduction of the technical performance, economic performance and safety performance of the ball mill to varying degrees. In addition, the ball mill operators should also ensure the daily cleaning of the equipment to prevent the ball mill from corrosion, rust, even blockage, wear and other problems caused by the “freezing” of impurities.
- During winter operation
■ warm up in advance when starting up in winter. The temperature is low in winter, and the electric control devices of the ball mill generally set the starting temperature (about 22 ° – 23 ° C). If the ball mill is not preheated, it cannot be started or can not work normally;
■ during production in winter, pay attention to the tail gas and thermal insulation of the dry mill. If it is lower than the dew point, cooling water will appear and damage the dust collector;
■ considering the factors of thermal expansion and cold contraction, the operator should always tighten the screws at the main parts of the ball mill, check the hollow shaft, main bearing, cylinder, reducer, large and small gears and other important parts, and make records;
■ do a good job in temperature control and inspection. During the operation of the ball mill, the lubricating oil temperature of the main bearing shall not exceed 55 ℃, the temperature of the 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 will generate heat by friction during operation, resulting in a rise in temperature;
■ check whether there is ore leakage at the bolt connection of ball mill cylinder, cylinder and end cover, ore feeding trolley and so on;
■ monitor the wear of steel balls in real time to ensure timely replacement in case of serious wear.
- Stop grinding in winter
■ if the grinding is stopped for a long time, turn the three-way cock installed at the water outlet of the main bearing to the drainage position, and use the siphon to drain the accumulated water in the water channel of the spherical tile string, so as to avoid frost cracking of the spherical tile or bearing seat;
■ when the grinding is stopped for a long time, stop the cooling water after the grinding body temperature is completely reduced to the same as the ambient temperature, and blow out the water in the main bearing bush with compressed air;
■ after stopping the grinding, turn the grinding for half a circle every 5-10 minutes or so and stop at the original opposite position until the grinding body is fully cooled to prevent the deformation of the grinding body;
■ the steel balls and materials shall be poured out in advance to avoid deformation and bending of the ball mill cylinder and scabbing of the steel balls and materials.
- Daily cleaning
■ ensure that there is no dust in the operation room or machine room, and the parts, materials and tools are stored neatly;
■ it needs to be cleaned by staff in shifts and once a week;
■ except for the operation part, all platforms shall be cleaned in time without ash accumulation.
Do a good job in ball mill lubrication
With the arrival of winter, the temperature decreases, the viscosity of lubricating oil increases and the fluidity decreases, which has a great impact on the lubrication effect of ball mill.
Due to the large temperature change during shutdown and operation, the valve shall be adjusted every time the ball mill is started to make the oil supply pressure reach 0.2 ~ 0.4MPa. However, with the increase of operation time, the lubricating oil temperature increases, the viscosity decreases, and the pressure decreases. If the valve is not adjusted in time at this time to increase the pipeline resistance, the continuous low oil supply pressure will cause the thin oil station to alarm and stop grinding. Therefore, it is very important to lubricate the ball mill after entering winter.
■ low oil grade lubricating oil is selected, which is thin and can ensure good fluidity at low temperature. High oil grade lubricating oil is used, which is thick and has poor fluidity. If there is no heating and lubricating oil preheating device indoors, the oil pump station will not work at all;
■ at the beginning of winter, all lubricating oil shall be discharged when the ball mill is put into continuous operation for one month, thoroughly cleaned and replaced with new oil;
■ when starting up, refueling or changing 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 shall be discharged and heated to 20 ℃ before starting the machine, and then poured into the bearing.
Configure the spray lubrication system of large and small gears, enhance the lubrication effect, reduce gear wear, automatically control the injection volume and display the working process to ensure stable lubrication status.
■ do not use deteriorated or unclean lubricating oil;
■ before adding new lubricating oil, filter the new lubricating oil;
■ check the lubrication and oil level at each lubrication point at least every four hours.
The above are the basic precautions for daily maintenance and repair of ball mill in winter summarized by Fodamon engineer. Under the harsh environment, the operators should focus on prevention, adhere to the combination of daily equipment maintenance and scientific planned maintenance, and ensure the good working condition of ball mill equipment through “combination of operation and inspection”, so as to ensure the economic benefits of the concentrator.