The initial construction scale of Xinjiang opencast coal mine was 1.5 million t/a, and after being put into operation, the scale gradually reached 7 million T /a after repeated renovation. At present, the mine adopts semi-continuous mining technology, which is mainly composed of fixed crushing station under pit, 1" screening workshop, final coal loading bin, 3# and 4 screening crushing system, coal storage facilities, off-site road and living facilities. Due to the small equipment selection of 3 screening crushing system, the crushing station, loading warehouse and other related facilities cannot produce at full capacity. At present, part of the lack of capacity depends on the ground flow crushing station. Meanwhile, in order to solve the problem of drainage in the mine, a new set of crushing station and related conveying facilities are set up in the southeast of the mine.
The semi-continuous mining process is between continuous process and intermittent process, which can complement the advantages of both. As the core equipment of the process, the crushing station not only accepts the materials unloaded by the dump truck in the discontinuous process, but also connects with the mobile belt conveyor in the continuous process, playing an important role in connecting the above and the next. According to whether they have walking devices, common crushing stations are mainly divided into three types: fixed type, semi-mobile type and full-mobile type. The fixed crushing station is simple in structure, but it needs a lot of civil engineering and is not easy to move, and with the increase of the depth of the stope truck distance and cost; Although fully mobile crushing station can follow the stope constantly moving, but its structure is complex, high technical content and expensive: feeder breaker structure is relatively simple, can be moved and installed by block through track car, flexibility is greatly increased than fixed type, high cost performance. The mining mode of single bucket, one truck, one feeder breaker belt conveyor has been widely used at home and abroad with mature technology. The newly added crushing station in Xinjiang coal mine is set in the southeastern part of the pit, with open layout to accept the raw coal transferred from the mining face by the dump truck: the coal particle size of the mining face is large, in the range of 0-1000mm, which can be crushed to less than 250mm and transferred into the coal transport system. With the change of mining location in open pit coal mine, crushing station can be moved to a new location and heavy duty system can be adopted. According to the mining technology and site requirements of Xinjiang coal mine, feeder breaker structure is undoubtedly the best choice for the new crushing station. 2feeder breaker structure and key components
feeder feeder, which integrates the functions of material acceptance, conveying and crushing, can meet the requirements of large and medium-sized open-pit coal mine for centralized operation of materials. It is the core equipment for semi-continuous mining of open-pit mine. It mainly includes receiving bin, feeder, main steel structure, crusher, operation room, discharge belt conveyor and other components.
2.2 Key components (1) Receiving bin The receiving bin is a steel structure spliced bin, and the volume of the receiving bin should fully consider the discontinuity of truck transportation. The crushing station is equipped with a unloading section, which is unloaded from the dump truck to the steel bin, and the storage capacity should meet 3 unloading Spaces. The receiving bin has changed the structure of the traditional receiving bin, designed into a polygonal sliding bin structure, can make the material slowly slide to the feeder, effectively reduce the impact of dumping hundreds of tons of materials in the dump truck on the receiving bin and the feeder, to achieve the purpose of slow feeding, impact resistance.
According to feeding mode, there are plate feeder crushing station and heavy duty scraper crushing station. The material of plate type feeder crushing station is transported by rolling friction, with low installed power, but the coal is serious in the return section of plate type feeder, so a sweeping belt conveyor or scraper conveyor must be arranged under the plate type feeder, which leads to complex process system, higher coal unloading platform, high operating cost of dump truck, and high cost of plate type feeder. The heavy scraper conveyor has the advantages of simple structure, low manufacturing cost, large processing capacity, high tensile strength of the scraper, and the ability to resist the impact of large materials is obviously better than that of the plate feeder. Therefore, the feeder breaker is designed with a heavy duty scraper feeder. According to the crusher form, hammer crushing station and double tooth roller crushing station are most popular. Hammer crushing station has the advantages of simple structure, saving construction cost, short installation cycle and overload protection. However, the crushing of slender materials in the hammer crushing station only depends on the extrusion pressure between materials, and the hammer head cannot act directly, resulting in the slender materials can not be broken and directly enter the follow-up system through the crushing chamber, affecting the operation of the follow-up system. The double-toothed roller crushing station has the advantages of compact structure, small size, large processing capacity, strong adaptability to materials, no clogging: the product size and shape are easy to control over crushing small, simple operation and double overload protection function. Therefore, the feeder breaker is designed with double tooth roller breaker. To sum up, the semi-mobile crushing station adopts modular arrangement dump truck to unload coal into polygonal sliding silo, and the heavy scraper feeder sends the material to the double-toothed roll crusher. The crushing is suitable for the long distance transportation of the belt shaft, and the layout is along the surface of the open pit mine. The current material receiving, crushing and transportation are integrated operation.
Technical characteristics