مراحل استخراج گرانیت و الزامات فنی

استخراج گرانیت به طور کلی به مراحل زیر تقسیم می شود:

معدن گرانیت, اول از همه, با توجه به شرایط منابع و تقاضای بازار, اولین منطقه معدن را انتخاب کنید, تعیین مرز معدن, mining production scale, mining work system, غیره. Mining is carried out on the basis of comprehensive analysis of natural environment, economic and technical conditions. The mining process can be divided into development transportation, stripping and mining.

1. Development transportation and loading

The task of development transportation is to open up the transportation route between the mining industrial area and the working steps in the mining area and the transportation route to the waste rock dump. Common development transportation methods for granite open-pit mines are:

(1) Highway development car transportation, which is flexible and can give full play to the efficiency of loading equipment and is widely used.

(2) Trenchless development mast crane hoisting. This method does not require digging a transportation trench from the surface to the mining step, and directly loads the transportation equipment by mast crane. This method has a small amount of engineering and low investment, but is limited by the capacity and working range of the mast crane and has poor flexibility.

In addition, there are also methods such as slope winch highway development trolley transportation and highway car and mast crane combined development transportation.

There are two types of loading equipment for loading raw materials onto transportation equipment: fixed and mobile. Mast cranes are fixed. They have a large lifting height and a large lifting capacity, and can be used for both loading and transportation. Crawler cranes and tire cranes are mobile loading equipment. They are flexible and maneuverable, but have a small lifting height and a small lifting capacity, and are not suitable for loading large-sized raw materials. Mine waste rock transportation usually uses manual carts, front loaders, bulldozers, cranes, cars and other equipment.

2. Raw material mining can be roughly divided into the following processes:

(1) Overburden stripping: It is the process of stripping the floating soil layer and non-ore rock layer covering the ore to facilitate ore mining. At present, most mines use manual stripping, and only some mining areas use mechanical stripping such as bulldozers and wheel loaders.

(2) Separation: It is the second process of separating the strip blocks from the original rock of the ore layer. Limited by the scale and production methods of existing mines, mining basically uses two methods: manual drilling and controlled blasting. The manual drilling and splitting method is to use traditional manual drilling and wedge splitting. This method is laborious and inefficient, but has a high scrap rate and is easy to shape; the controlled blasting method is to use a handheld pneumatic drill to drill holes and use black powder or small gunpowder rolls for controlled blasting.

(3) Turning over: turning the strip block over to facilitate its cutting and separation. There are many tools for turning over, including manual jacks, hydraulic rock lifters, airbags, traction methods, غیره. At present, the main methods used in mines are jacks and traction methods.

(4) Disintegration and segmentation: dividing the strip block into blanks or waste according to the required scale. The disintegration and segmentation methods are roughly similar to the separation method, mainly using manual wedges, drilling and splitting, controlled blasting and other methods.

(5) Shaping: Shaping is to process the split blanks into finished waste that meets the scale through certain processing. Shaping methods include manual hammering, small handheld drills, handheld rock drills, beaded diamond wire saws, shaping machines, غیره. At present, the methods used by mines are mainly simple methods such as manual hammering and chiseling, without mechanical operation.

(6) Lifting and loading: It is the process of transporting the processed roughcast to the transportation tool. There are many kinds of lifting tools. At present, most mines use mast cranes, and a few mines also use truck cranes, loaders, and crawler cranes.

(7) Mud removal: It is the process of transporting the crushed non-raw stone away from the raw material processing site.

Technical requirements for granite mining

Under normal conditions, when the production stripping ratio is about 0.3, the minimum economic raw material rate of granite mines is 15% به 25%.

(1) When a mobile crane is used in the mining area, the step height is 4 to 6m; when a small mast crane is used, the step height is less than or equal to 14m; when a large mast crane is used, the step height is less than or equal to 62m. The step slope angle is generally 90°, and the final slope angle is determined according to the stability of the rock mass.

(2) The width of the stone strip is determined according to the performance of the mining equipment, the waste specifications and the crack conditions, and is generally 1 to 3m.

(3) The length of the working face is generally 5 to 15m for manual mining and 15 to 20m for flame cutting machine mining. The minimum working platform width: generally 20 to 25m.

Overall, the current mining work is mainly in a semi-mechanized and semi-manual mining state, and has not yet formed a certain scale, and the management lacks unification and systematization.