The comprehensive mining method is characterized by the fact that the working face moves along the ore body or along the inclined surface. The exposed area of ​​the stope is large, and the operation is carried out under the exposed roof. In the process of mining, the lean or stone in the ore body is generally left behind. If it is not taken, it will play the role of the pillar to maintain the goaf. These so-called pillars are irregular and generally no longer recover. If the recovery of precious and rare metals can also be manually set up the pillar without leaving pillars. Comprehensive mining method: the gently inclined ore body is divided into 15 to 30 m vertical height, and the stage length is 40 to 60 m. The top and bottom columns of 2 to 3 m are left between the stages, and the ore is still 50 to 60 m. The bearing area of ​​the stope can generally reach 1000~2000m 2 . When the forward recovery sequence is adopted, the stage transportation roadway should be ahead of the mining working surface by 30 to 50 m. This mining method can be divided into two types: intrapulmonary and extrapulmonary. In the excavation stage, the roadway is transported. In the stage, 1~2 uphills are taken as free faces. The bottom of the bottom column is opened every 5~6m. On the other side of the transport roadway, the electric winch winch chamber is set every 20m. The recovery sequence can be forward or reverse. The cut-off of the mountain in the ore can be spread to one side or both sides. For ore bodies below 3m, the comprehensive mining method is generally used for single-layer mining. When the thickness is large, it is layered with positive steps. The layering height is 2~3m, and the upper layer is 3~4.5m ahead, so that the bolt support can be carried out when necessary. . The falling mine adopts shallow hole rock blasting, and the hole depth is 1.2~3m. When the ore body thickness is small, it can be transported by electric raft. When the ore body is thick and the inclination angle is also small, the ore can also be transported by the trackless self- equipment . The transport distance is less than 200-300m, and the scraper of 20t or more is used. When the transport distance is larger, the dump truck can be used for 20~60t. Loader kit.
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The characteristics of children's book printing services are high printing quality, bright colors, full patterns, clear fonts, easy to read, and in line with children's psychological and cognitive characteristics. Attention should be paid to the use of environmentally friendly printing materials during the printing process to ensure the health and safety of children.
Children's book printing services usually include design, plate making, printing, binding, and other links. In the design process, it is necessary to consider factors such as children's age, gender, hobbies, and other factors to design patterns and formats that meet children's aesthetic needs. In the plate making process, high-quality printing plates should be used to ensure the restoration of colors and patterns. In the printing process, high-quality printing equipment and environmentally friendly printing materials should be used to ensure the quality and safety of printed products. In the binding process, it is necessary to choose a binding method suitable for children to ensure the durability and ease of reading of the book.
The comprehensive mining method is generally used in a mining method for mining gently inclined, thin and medium-thick ore bodies in the open field mining method. The single-layer mining requires that the ore is stable.