Mining and its types
Mining is a cavity that formed in a mountain massif after extraction of minerals and rocks from it.
Depending on the purpose, work with the rock is divided into species.
Process description
Underground mining is characterized by the fact that itsThe cross-section has a closed circle, regardless of whether there is a direct exit to the surface. In addition to underground work, there are those that are carried out on the ground. Open mining has a non-closed contour of the cross section.
Under the underground method of work, it can be:
- mining exploration;
- Mining and capital;
- Mining and preparatory;
- threaded;
- mortgage;
- cleaning.
Mining, depending on the destination,is exploratory and operational. The first one is used for exploration and prospecting of new deposits, the second - for development of deposits with the purpose of extracting minerals from the bowels. Operational work is divided into disclosure, preparation and purification.
Disclosing mining is designed to open the mine and provide access to minerals.
Preparatory works are preparing for the development of a mine field, and in the process of purification from ore, minerals are released.
The species of the rock determines whether the formation or the field will work. The first is conducted along the bed, the second - along the empty rocks.
Mining can be extended andvolume, which is determined by the relationship between the longitudinal section and the cross-sectional area of the processed rock. Extended, in addition, are horizontal, inclined and vertical.
Open mining is divided into trenches, ditches, wells, congresses.
Transverse section
The shape of the cross section in the horizontal method depends on the properties of the rocks and their state, the direction and force of the rock pressure, the service life and the fixing structure.
The vaulted shape of the cross section is given to workings that can not be fastened, since it is close to the shape of the natural arch.
If there is no lateral pressure of the rocks, a rectangular cross-sectional shape is used. In this case, the development is fixed with a wooden, mixed or rod fastening.
Trapezoidal form withstands both vertical and lateral pressure. The fastening is made of wood, prefabricated reinforced concrete and metal.
The vaulted form is used for concrete and stone fastening.
Arched fastening is used at vertical and lateral pressure of rocks. In this case, the development is strengthened by various metal arches.
With all-round pressure best suitedround section. Coal wells may not be attached at all. Ellipsoidal cross-section is used if one of the pressure components is much larger than the others.
In the construction of tunnels, hydrotechnicalstructures, subways use elliptical intersections with the horizontal and vertical axes. The shape of the cross section depends on what the mine is designed for, and also on the mining conditions. In particular, the vector is affected by the vector of the action of the maximum pressure component, in parallel with which the axis of the ellipse is located.
