1 The complex rock and surrounding rock are soft and easy to collapse; 2 the steep ore thick ore body. (When the ore body falls <4~5 meters or the inclination angle is small, the "false roof" is difficult to fall, increasing the loss of pit wood consumption and loss of ore and depletion); 3 the ore of various hardness and medium-priced ore. Advantages: 1 Loss of ore, low depletion. 2 The mining and recovery work is simple (roadway or recovery); 3 Application flexibility (some hand selections can be made on the work surface). Disadvantages: 1 Nugget productivity and labor productivity are low; 2 pit wood is expensive and there is a fire hazard; 3 Poor ventilation. Archway Metal Detector, in some place people call like that, also because it's designed like archway gate. Mostly they are 6 Zones Archway Metal Detector, but also 18 zones, 33 zones. Archway Metal Detector Gate protect people's life from being hurt and property being damaged by terrorism. Chinese Walk Through Metal Detector is cheap but also good in use. And also offer 1 year warranty, it worth your choice! Archway Metal Detector Archway Metal Detector,6 Zones Archway Metal Detector,Waterproof Archway Metal Detector,Arched Metal Detector Shenzhen Mama Security Technology Co., Ltd. , https://www.mamasecurity.com
The stratified caving method is to return the mining block (or stage) from the top to the bottom, and at the same time, as the mining work declines, the rock formation and surrounding rock are covered and collapsed in time, filling the goaf. Complex before crumbling rock, the base plate has been required in the mining face, Cushion (i.e., off the top) sheet with a large (or metal mesh). Under normal circumstances, the thickness of the "false roof" should be greater than one layer height.
(2) Applicable conditions
(3) Evaluation
The essence and evaluation of stratified caving
(1) The essence of the stratified caving method