Granite mining knowledge
In granite mining, the first mining area should be selected according to resource conditions and market demand, and the mining boundary, mine production scale and mine work system should be determined. On the basis of comprehensive analysis of the natural environment, economic and technical conditions, mining is carried out. The mining process can be divided into development and transportation, stripping and mining.
The mining mountain should be stripped of surface overburden, weathered layer, interlayer, surrounding rock and some crushed ore with no mining value.
The basic process of granite mining: separation, segmentation and shaping.
(1) Separation process: Commonly used methods include split separation, drill and blast separation, flame cutting separation and combined separation.
(2) Splitting and separation: Several iron wedges can be directly driven into the rock mass at certain intervals. In this way, cracks can be generated in the rock mass as required. This method is suitable for small mines, with low cost and low efficiency. Another method is to separate the expansion agent in the borehole, mix the expansion agent with water, and pour it into the drainage hole of the borehole. The swelling force generated by the hydration of the expansive agent is used to break the rock mass. This method is simple and safe, but not efficient.
Flame cutting and separation: high-speed flame is sprayed from the nozzle of the flame cutting machine, heating and impacting the rock. Because different minerals in rocks have different response characteristics to heat. So they will burst and peel off, and gradually form separation grooves. This method is only suitable for rocks with high time content, small heat capacity, and poor thermal conductivity. Such as granite, diorite and syenite.
Rock drilling and blasting are separated: the rock drill drills holes in the rock mass and loads blasting materials (currently using black powder, combustion agent and detonating cord) for controlled blasting. This method has high efficiency and a wide range of applications, but the blasting force should be strictly controlled in use. Avoid harmful cracks.
(3) Segmentation process: the strips separated from the rock mass are turned over with a top rock machine (or top rock bag). Then, according to the crack law and the specifications of the waste material, the strip stone is divided into the required waste material by the splitting method.
(4) Forming process: Reshape the cutting waste that does not meet the requirements. Commonly used hammer drilling method or forming machine to remove the excess waste part, make it smooth and neat.
Let's take a look at the fire drilling method.
Fire drilling
The rock-drilling mining method discussed here is a manual drilling using flame cutting, hand-held rock drills. Combine the detonating cord to control the blasting method of mining granite. Rock drilling technology and technology is the basic method of granite mining in my country, and it is also the most widely used granite mining method.
The main mining process of fire drill mining is similar to artisanal mining. In order to make the separation between the separated body and the ore body easier and more reliable, a flame cutting process is added, and the joint surface between the separated body and the ore body is cut with a flame cutting machine. The separated body and the ore body are connected by only a vertical surface and a horizontal bottom surface. In the subsequent blasting separation of the separated body, a state of controlled blasting on both sides is formed, making the separation operation easier and more reliable. Except for burning and separating one side of the separated body, the other processes are the same as the above-mentioned artificial mining method.
