Energy saving and consumption reduction has become a very important task in the sustainable development of concentrators. We should take various effective measures to improve production efficiency, reduce energy consumption, and then improve the economic and ecological benefits of concentrators. The common methods of energy saving and consumption reduction in concentrators are as follows:
1. More grinding and less grinding to determine reasonable grinding size
Production practice shows that about 60% of energy consumption in mineral processing is consumed in the grinding operation of ore, so energy saving in mineral processing should first work hard in the grinding stage. For the concentrator being produced, the crushing and grinding equipment has been basically fixed, and efforts can only be made on how to balance the crushing and grinding capacity. This requires that, on the basis of guaranteeing the crushing capacity, the discharging outlets of crushers in each section should be adjusted reasonably, and the comprehensive capacity of crushing system should be brought into full play so as to reduce the final particle size of crushing system, reduce the pressure of grinding section and increase grinding efficiency.
2. Automatic control of crushing production
The automatic control system can realize the functions of sequence control, logical chain control, fault protection control, automatic control of crusher feeding and automatic control of ore bin distribution of crushing process equipment, reduce the labor intensity of workers, reduce the rate of equipment failure and improve the production efficiency of equipment.
3. Selection of High Pressure Roller Mill
High-pressure roll mill is composed of a pair of rollers which rotate synchronously in opposite direction. One of them is fixed roll and the other is movable roll. Compared with other crushing equipment, it has obvious energy-saving advantages. Material enters from the inlet port above the press roll and is brought into the roll room by the rotation of the press roll. After strong extrusion, crisp muffin is formed and discharged from the machine. In the crushing process of high-pressure roller mill, quasi-static crushing is implemented, which saves about 30% energy consumption compared with impact crushing. High-pressure roller mill implements material layer crushing, which is the mutual crushing between material and material. Comparing with other crushing methods, the crushing energy loss of compressive stress material layer is small, and the utilization ratio is high. The discharged cake not only contains a large proportion of fine particles, but also produces a large number of cracks in the particle, which improves the grindability of material for subsequent grinding, increases the production capacity of grinding system, and greatly reduces the grinding power consumption and steel consumption.
4. Selection of efficient large grinding equipment
Large grinders generally use advanced equipment such as hydraulic power, hydrostatic bearings and fuel injection devices, which effectively improve the economic benefits of the operation of the mill. At the same time, its unit energy consumption is significantly lower than before. The use of large ball mills can not only reduce energy consumption, but also enhance the stability of the process and improve production efficiency.
5. Improving classification efficiency
Classification efficiency has a very significant impact on the production capacity of concentrators. In order to ensure the scientificity and rationality of classification size, many concentrators currently use closed circuit grinding classification system in production. Overgrinding is particularly common in concentrating production, and it is also an important source of energy consumption.
Overgrinding is closely related to classification efficiency. At the present stage, a large number of new equipment are gradually appearing in the production link, which also ensures the effect of strengthening classification. Furthermore, the coarse-grained classification can also be accomplished by means of fine screening, so as to reduce the energy consumption produced in the operation of the screw classifier. High efficiency separation equipment such as hydrocyclone or high frequency fine screen can be used in fine particle classification. Under the function of intensified classification operation, the system can separate qualified particles in time, avoid over-grinding and effectively reduce energy consumption in grinding process.
6. Automatic control of grinding and classification
Actively take effective measures to implement automatic control. The automatic control system of ball mill can detect the audio frequency, power and grading current of the mill by itself, and make a comprehensive analysis and study of the running state of the mill. The automatic control can be realized in the aspects of ore feeding, concentration and grading overflow granularity. The efficiency of grinding and grading can be improved continuously, and the function of grinding and grading machine can be displayed to the greatest extent.
The investigation shows that after the automatic control of grinding and classification circuit, the output of grinding machine and the recovery of beneficiation metals increase obviously, the energy consumption decreases by 10%. The grinding process has strong stability and obvious advantages.
7. Selection of efficient sorting equipment
The use of new and efficient sorting equipment is one of the keys to realize energy saving and consumption reduction in sorting. At present, various types of flotation equipment emerge in an endless stream, and the quality is different. When selecting flotation equipment, schemes should be compared according to different conditions. For example, compared with the small flotation machine, the large flotation machine has the characteristics of low energy consumption, small floor area and high automation. Compared with the flotation machine, the flotation column can simplify the cleaning times, reduce the dosage of reagents and reduce energy consumption when obtaining the same grade.
8. Using Frequency Conversion Control Technology
As an effective way to save energy, frequency conversion control has been widely used in many mines. Frequency converter can realize soft start of motor, achieve energy saving and speed regulation by changing the input voltage frequency of equipment, and provide protection functions such as over-current, over-voltage and over-load for equipment. Frequency conversion control can be used on belt conveyor, compressor, slurry pump and other loads, which can not only rationally adjust process parameters, but also significantly reduce energy consumption.
9. Electricity for peak avoidance and valley filling
Because the peak price is much higher than the valley price, the implementation of peak power transfer, peak avoidance and valley filling, although the total electricity consumption has not been reduced, but can greatly save electricity costs and reduce production costs. Most concentrators produce continuously, but some links can be controlled. The crushing process makes full use of the powder silo in the intermediate buffer link of mineral processing production, carries out reasonable regulation and control, avoids peak and fills valley, carries out equipment maintenance during the peak period of power consumption, enlarges horsepower production during the peacetime and valley period, and only opens the main production equipment during the peak period of grinding and separation process, so as to minimize the cost of electricity consumption.
10. Continuous optimization of mineral processing process
Technology, equipment and technological process have a very significant impact on the quality and efficiency of production. Advanced energy-saving technology and energy-saving equipment improve the quality of mineral processing and simplify the process of mineral processing. If energy-saving technology and equipment can be applied scientifically in the process of mineral processing, it can play a positive role in a variety of processes, technologies and equipment, on the one hand, simplify the process. Processes, on the other hand, also reduce energy consumption.
In short, energy saving and consumption reduction is a long-term and arduous task for mineral processing enterprises. We should tap the potential of energy saving and continuously develop and apply new energy-saving technologies, new technologies and new equipment.