At present, many mines in the United States adopt the stage natural caving method, and this method is rarely applied in China, but the history of this method is still relatively long (about 50 to 60 years). This method is strictly used, so it is not widely used in China (nearly).   (1) The essen ......Reading more

Recently, the first national new energy vehicle charging facility quality supervision and inspection center in the province was approved to be built in Su, and is expected to be completed next year. At present, there is a lack of national testing centers for the detection and monitoring of electri ......Reading more

1. Geological factors Second, economic factors: Captive Panel Screws Material is Stainless Steel per ASTM-A581/A582. Ideal for use on equipment and electronics where mounting hardware is subject to loss.Keystone`s captive screws  are easily installed  for secure equipment assem ......Reading more

When mining is carried out by the caving method, the roof of the empty area or the rock on the upper plate may fall. With the expansion of the goaf range, the range of slump and uneven subsidence will involve large rock masses, and the roadways will also be dragged to cause deformation and damage. I ......Reading more

Regardless of the deepening construction plan, protection devices must be provided between the production stage and the extension section, or the protective rock pillars (8~10m ) should be reserved , or artificial protection plates (4~8m ) should be constructed to prevent the accident. When lifting ......Reading more

In the 1980s, paste filling technology was successfully tested in the Grunde mine in Germany [1], which solved the problem of serious low-concentration slurry filling and bleeding. 90 years of Gansu Jinchuan built a paste filling system [1], the system in preparation paste and delivery terms for ou ......Reading more

When the top plate is partially soft or has fallen, and it cannot be supported by a single column or a column, it is suitable to use the raft support. The raft supports the pressure of the stope and can be a solid raft or a hollow raft. In practical work, wood substitutes should be sought as much a ......Reading more