Dust treatment in the crushing workshop of the beneficiation plant is a systematic project, which requires specific dust conditions (temperature, humidity, particle size, acidity and alkalinity, cohesiveness, infiltration, etc.), pipeline layout, collection methods, and equipment at specific dust process points. Comprehensive consideration of all aspects such as operating cycle. We have summed up the dust management experience in the crushing workshops of hundreds of mines in quarries, copper mines, iron ore, lead-zinc mines, etc., and put forward the following problems that are prone to dust management in mine crushing workshops.
Summary of problems that often occur in dust removal systems
1. The total air volume of the system is unreasonably selected. If the total air volume of the system is too large, the equipment investment will be large, the equipment operation will consume a lot of electricity, and the operation cost will be high. If the total air volume of the system is too small, the dust collection will be incomplete and the dust control effect will be poor.
2. The selection of dust control points is unreasonable. Unreasonable and incomplete selection of dust control points, omission of dust sources, improper size, shape, and location of the dust hood will affect the dust control effect.
3. Unreasonable selection of pipe wind speed. If the wind speed of the pipeline is too low, dust is easy to deposit in the pipeline, which affects the operation of the equipment. If the wind speed of the pipe is too high, it is easy to cause abrasion of the pipe.
4. The pressure in the pipe network is unbalanced. The system has not performed reasonable pressure balance calculations, and the air volume and pressure distribution of each dust point are unbalanced, and the dust collection effect of each dust point is difficult to achieve the ideal state.
Summary of the prone problems of bag house dust collector
1. The filter wind speed of the bag filter is unreasonable, the filter wind speed is too low, and the equipment cost is high. If the filter wind speed is selected too high, the dust bag is easily damaged, and the filter bag is replaced frequently, which increases the maintenance cost. If the damaged filter bag is not replaced in time, the fan and other equipment behind it will be damaged.
2. The design and manufacture of the dust hopper of the dust collector is unreasonable, which makes it difficult to unload the dust and causes the dust collector to be blocked.
3. The backward dust removal method of the dust collector is likely to cause incomplete dust removal of the filter bag, which increases the energy consumption of the fan.
Reasonable dust removal design plan requirements
Based on the above problems, we should pay special attention to the following points when designing the dust removal plan for the concentrator:
1. It is difficult to collect fine dust. A bag filter and polyester needle felt filter cloth with better filtering effect should be used. The compressed air pulse cleaning method is adopted, and the cleaning effect is better.
2. Each dust point is equipped with a dust suction hood, and the hood mouth is downward facing the dust diffusion direction, which is beneficial to dust collection. The gaps around the dust points should be sealed as much as possible to reduce the amount of air used for dust collection as much as possible. Reduce equipment investment and energy consumption.
3. At the bottom of the dust collector, a screw conveyor and a star-shaped unloader with air lock function are installed at the bottom of the dust collector to gather the dust collected in the dust collector in one place for easy recycling.
4. The dust collecting hood should be as close as possible to the dust source under the premise of not affecting production and maintenance, and should be kept as airtight as possible.
5. The dust suction cover of the vibrating screen adopts the sealing cover of the upper part of the vibrating screen. The gap between the sealing cover and the vibrating screen is sealed with a rubber plate. The front and top of the dust hood are provided with movable inspection doors to facilitate inspection and repair.
6. The distance between each dust hood and the dust source should be reasonable, and the dust suction port should be equipped with a protective net to prevent foreign matter from entering the dust collector and jamming the rotary unloader.
7. According to the collected mineral dust hardness, dispersion and other physical properties, combined with professional standard requirements and practical experience, comprehensive consideration of equipment investment, motor power, maintenance costs and other factors, the filter speed of the dust collector should be less than 1.2m/min.
8. Design the system pipe network according to the air volume allocated by each dust point, and select a reasonable pipe wind speed. At the same time, consider the pressure balance of each suction point. In addition to the reasonable selection of pipe diameters, an air regulating valve should be installed as an auxiliary measure to adjust the pressure balance.
Reasonable pipe wind speed is the key to the normal operation of the entire dust removal system. If the pipe wind speed is selected too high, the resistance of the system pipe network will be too large, the total air volume of the system will be reduced, the dust collection effect will be worse, and the dust will accelerate the wear of the pipe. If the pipe wind speed is too low, it will cause large-size dust to settle inside the pipe and affect the normal operation of the dust removal system. At the same time, if the pipe wind speed is too low, it will increase the investment.
According to requirements, the minimum wind speed of heavy mineral dust vertical pipeline is V=10m/s, and the minimum wind speed of horizontal pipeline is V=12m/s.
9, Recovery and utilization of dust in the crushing workshop of the concentrator.
After adopting the bag pulse dust collector, 99.99% of the dust sucked into the dust collector is collected. After the dust in the crushing workshop of the concentrator is treated, the clean production of the crushing section can be completely realized, and the occurrence of occupational diseases can be prevented. At the same time, if reasonable dust recovery equipment and technology are used, a large amount of high-value mineral powder can be recovered, creating greater economic benefits.