Cradle to Gate
Identity ID
796277af-3c97-4f65-892f-87174357fa09
Materials
Associated ID
c7dce94c-3d13-48e7-9a13-c44f0387ea32
Included activities starts
Included activities ends
Description
This dataset represents a life cycle inventory (cradle-to-gate) of bituminous and anthracite production starting from open-pit coal mining, covering all activities related to raw coal production but excluding coal washing processes, as well as direct or indirect greenhouse gas emissions from the production of equipment such as conveyors and mining vehicles, personnel transportation during coal production, and daily office operations. The dataset was compiled from multiple data sources based on national standards such as "Clean Production Standards for Coal Mining and Preparation Industry" (HJ 446-2008), "Emission Standards of Pollutants for Coal Industry", and "Soil Environmental Quality Standards" of the People's Republic of China, and is representative of the average production level in Shaanxi.
Activity Description
This dataset describes underground mining of bituminous coal and anthracite, with the following process steps:
1. Drifting
The first step in underground mining is drifting, which involves creating tunnels to access coal seams. These tunnels are typically excavated using roadheaders or blasting methods. Drifts are categorized into main tunnels (such as haulage and ventilation drifts) and auxiliary tunnels (such as personnel access and drainage drifts), serving purposes including coal transportation, ventilation, personnel movement, and the handling of equipment and waste materials. Coal Mining
After the completion of roadway excavation, coal extraction is the core step in underground mining. Depending on the coal seam structure, thickness, and mining technology, different coal mining methods are employed. Common underground mining methods include:
Longwall Mining: A large-scale mining method where the coal seam is extracted over a wide area at once, usually accompanied by roadway support.
Room and Pillar Mining: The coal seam is divided into smaller blocks, supported by pillars, and mined progressively. Machinery and Equipment
The coal mining and transportation process heavily relies on machinery and equipment, including:
Coal Cutters: Used for cutting coal seams in longwall mining.
Hydraulic Supports: Support the roof to prevent tunnel collapse.
Roadheaders: Used for tunnel excavation.
Belt Conveyors: Transport extracted coal from the working face to the transportation system. Underground + In-plant Transportation
Underground transportation refers to moving coal from the working face to the shaft mouth, typically using belt conveyors or mine cars. After reaching the shaft mouth, coal is transported to coal preparation plants or external markets via in-plant transportation systems (such as belt conveyors or trains). Improving the efficiency of this stage directly affects the overall production process efficiency.
5. Ventilation
Ventilation systems are an essential component of underground mining. Due to the confined nature of underground working environments, ventilation systems must ensure a continuous supply of fresh air, while removing harmful gases (such as methane) and dust to safeguard worker safety. A typical ventilation system consists of fans, ducts, and vents, which together maintain airflow underground.
6. Pollutant Treatment and Disposal
The main pollutants generated during underground mining include:
Mine water: Typically contains coal dust, suspended solids, and chemicals, which require treatment through settling ponds and water treatment facilities.
Coal dust: Poses hazards to miners' health and the environment, usually controlled by wet dust removal, spray suppression, and other methods.
Waste residue: Mine waste and rock are transported to the surface, stored in designated areas, and managed with reclamation measures. Ecological Restoration and Management
The impact of underground mining on the surface environment is mainly manifested in surface subsidence and changes in groundwater flow direction. Therefore, ecological restoration measures include:
Land Reclamation: Filling subsidence areas caused by mining to restore agricultural or vegetative land use.
Water Resource Management: Restoring groundwater systems and preventing water pollution or loss.
Vegetation Restoration: Planting vegetation in affected areas to prevent soil erosion and improve the ecological environment.
Process Description
The coal quality of bituminous and anthracite coal in Shaanxi Province is as follows: raw coal ash content 6.12–43.57%, volatile matter 4.68–53.54%, total sulfur 0.23–7.57%, and net calorific value on as-received basis (Qnet,ar) 4037–7045 kcal/kg. The washed coal ash content is 2.84–22.17%, volatile matter 7.06–44.61%, carbon content 76.84–95.78%, and net calorific value on as-received basis (Qnet,ar) 7324–8694 kcal/kg.
Time period
2022
2026
Geography
China,Shaanxi
Geography comment
Forming Shaanxi's average data through merging data from multiple sources
Macroeconomic value
Business-as-Usual
Data validation
Yes
Technology
Current Technology
Technology comment
Underground mining includes tunneling, coal extraction, machinery and equipment, underground and in-plant transportation, ventilation, pollution treatment and disposal, ecological restoration and management.