This dataset describes the process flow of underground mining for raw coal:\\n1. Development of access tunnels\\nThe first step of underground mining is the excavation of access tunnels, which means creating passages to reach the coal seam. These tunnels are typically excavated by roadheader or blasting methods. Access tunnels are divided into main tunnels (such as transportation tunnels and ventilation tunnels) and auxiliary tunnels (such as pedestrian tunnels and drainage tunnels), which are used for coal transportation, ventilation, pedestrian access, equipment, and waste movement. Coal mining After the development of drifts is completed, extracting coal is the central step of underground mining. Depending on the structure, thickness of the coal seam, and mining technology, different coal mining methods are used. Common underground mining methods include: Longwall mining: A large-scale mining method where the coal seam is mined over a large area at once, usually accompanied by drift support. Room-and-pillar mining: Dividing the coal seam into smaller sections, using pillars for support, and gradually exploiting it. Mechanical Equipment\\nCoal mining and transportation processes rely heavily on mechanical equipment, including:\\n- Coal cutter: Used for cutting coal seams in longwall mining.\\n- Hydraulic supports: Support the roof to prevent roadway collapse.\\n- Roadheader: Used for roadway excavation.\\n- Belt conveyors: Transport the mined coal from the working face to the transportation system. Underground + In-plant Transport\nUnderground transport refers to the conveyance of coal from the working face to the shaft collar, typically using belt conveyors or mine cars. After reaching the shaft collar, the coal is transported within the plant through systems (such as belt conveyors or trains) to the coal preparation plant or external market. Improvements in efficiency at this stage directly impact the efficiency of the entire production process. Ventilation\\nVentilation systems are an indispensable part of underground mining. Since the underground working environment is enclosed, the ventilation system needs to ensure the circulation of fresh air, removing toxic gases (such as methane) and dust to ensure the safety of workers. Ventilation systems typically consist of fans, ventilation ducts, ventilation outlets, etc., maintaining the circulation of air underground. Pollutant Treatment and Disposal\\nMajor pollutants generated during underground mining include:\\nMine water: It usually contains coal dust, suspended solids, and chemicals, which need to be treated via sedimentation tanks and water treatment facilities.\\nCoal dust: It can pose a hazard to miners health and the environment, typically controlled by means such as wet dust extraction and spray dust suppression.\\nWaste residue: Mine waste and waste rocks will be transported to the surface, stored in designated areas, and managed and reclaimed. Ecological Restoration and Management\\nUnderground minings impact on the surface environment is mainly reflected in aspects such as ground subsidence and changes in groundwater flow. Therefore, ecological restoration measures include:\\nLand reclamation: Filling in the subsidence areas caused by mining and restoring them for agricultural or vegetation use.\\nWater resource management: Restoring the groundwater system, preventing water pollution or loss.\\nVegetation restoration: Planting vegetation in affected areas to prevent soil erosion and improve the ecological environment.

The coal varieties in Hebei Province are complete, ranging from low-rank lignite to high-rank anthracite. The province mainly features coking coal with non-coking coal as a secondary type. The coking coals include gas coal, gas-fat coal, fat coal, coking coal, and lean coal and are mainly found in the Jingxing, Lincheng, Xingtai, Fengfeng, and Kailuan mining areas. Non-coking coals include lean coal, anthracite, weakly caking coal, non-caking coal, long-flame coal, and lignite and are mainly distributed in mining areas such as Weixian, Wanquan, Xuanhua, Liujiang, Sandhe, as well as Laiyuan Doujunwan and Fengning Qinglajar. The moisture content of these coals is between 0.56% to 1.98%, the ash content is between 7.92% and 42.69%, and the volatile matter content is between 2.34% and 43%. 99%, total sulfur 0.2~11.42%, Qnet,ar net calorific value on as-received basis 4122~8873 kcal/kg.