The length of the open-pit working line not only has a direct relationship with the production stripping ratio, but also has an impact on the distance of the open-pit and the amount of capital construction, thus affecting the economic benefit of the entire open-pit. At present, the coal seam mining of large open-pit coal mine mainly uses the semi-continuous process of single bucket excavation-truck semi-fixed crusher-belt conveyor, and the length of the working line plays a crucial role in the system. Compared with the semi-continuous process of the other moving crusher, the longer the working line, the more transportation costs are saved by the semi-continuous process of the self-moving crusher, and the higher the efficiency of the single-bucket excavator. In each link of the coal feeder breaker process, the equipment is fixed, that is, the annual production capacity of the whole system is certain. When the working line is short, the production capacity of the system will be affected by frequent shifting of the tape; When the working line is long, if the capacity of the coal feeder breaker process system is less than the advancing speed of the lower step, the inner dump can not follow up and the volume of the inner dump is reduced. Therefore, the reasonable working line length has a great impact on the performance of the process system.
1. The principle of determining the length of the working line
The length of the working line is determined by comparing the efficiency of the coal feeder breaker process with that of the single-bucket excavator in the semi-continuous process of the other mobile crusher. For the same single-bucket excavator, to complete the same workload, the required working time is the same, then by comparing the non-working time of the two process systems, the working line length suitable for the application of the semi-continuous process of the self-moving crusher is obtained. If the non-working time of the coal feeder breaker semi-continuous process is more than the non-working time of the continuous process of the other mobile crusher, it is not suitable to use the self-moving crusher semi-continuous process.
2. Non-working time of the process
The same amount of work in the same mine area means the same number of working zones, minus the same number of non-working hours, as compared to other mobile crusher semi-continuous processes, such as: The walking time of the single-bucket excavator, the time of the opening help incision, the time of the finishing work plate and the failure time of the single-bucket mining, etc., in order to simplify the research, the different non-working time only considers the internal factors of the system, and the maintenance time of other equipment is not considered. Therefore, compared with other semi-continuous processes of the mobile crusher, The non-working time of the coal feeder breaker process includes: walking time on the work surface and setting time of the belt conveyor. The traveling time of the self-moving crusher mainly depends on the traveling frequency, the length of the working line and the number of mining belts.
By analyzing the non-working time of the feeder breaker process and the semi-continuous process of other mobile crusher and comparing the non-working time of the two processes, the relationship between the efficiency of the feeder breaker process and the reasonable minimum working line length when the efficiency of the feeder breaker process is higher than the semi-continuous process of other mobile crusher is obtained. This paper provides the basis for the application of coal feeder breaker technology.
