Cradle to Gate
Identity ID
f6a246be-adc9-48be-8726-4e4e697f5b91
Materials
Associated ID
fd3ec9fd-80a6-421f-8472-bf090f4602dc
Included activities starts
Included activities ends
Description
This dataset represents the life cycle inventory (cradle-to-gate) for thermal coal concentrate production starting from coal preparation, covering all activities related to coal washing, but excluding conditions external to the coal preparation plant (such as raw coal mining, utilization of clean coal, etc.), as well as direct or indirect greenhouse gas emissions from personnel commuting and daily office operations during the coal washing process. Based on national standards such as "Clean Production Standards for the Coal Mining and Washing Industry" (HJ 446-2008) and "Emission Standards of Pollutants for Coal Industry", this dataset is compiled from data from multiple sources and represents the average production level in China.
Activity Description
Coal preparation refers to the process of removing gangue and other impurities from coal through various physical, chemical, or physicochemical methods, thereby improving coal quality. Below is a detailed description and introduction of the entire coal preparation production process in China:
1. Raw Coal Preparation
Coal Crushing and Screening:
Raw coal is first crushed by crushers into particles suitable for coal preparation. The crushed coal then enters screening equipment for particle size classification, directing coal of different sizes to corresponding coal preparation equipment.
The screening process can be divided into several stages to ensure that coal of different particle sizes receives optimal treatment. Pre-selection
Impurity removal equipment:
Before formal coal preparation, use magnetic separators, iron removers, and other equipment to remove metallic impurities and large gangue pieces from raw coal.
The goal of the pre-selection stage is to reduce the impurity content entering subsequent coal preparation processes and improve coal preparation efficiency.
3. Jig Coal Washing
Jigging separation:
Coarse coal is separated using a jig. The jig utilizes the pulsating action of water to stratify coal and impurities based on density. The lighter clean coal rises to the upper layer, while the denser gangue and impurities settle to the lower layer.
Coal enters the feed compartment of the jig and is mixed with water to form a slurry. Under the action of the jig, the clean coal and impurities are stratified. The clean coal is collected via an overflow trough or discharge device, while the impurities are discharged through a discharge outlet.
4. Dense Medium Coal Preparation
Dense medium separation:
Medium-sized coal is separated through a dense medium separator. In the dense medium suspension, coal with lower density floats, while impurities with higher density sink, thus achieving separation between coal and impurities.
Magnetite powder or other dense medium materials are mixed with water to form a suspension of specified density. After separation, the dense medium suspension passes through a magnetic separator to recover the magnetite powder for recycling.
5. Froth Coal Flotation
Grinding:
Fine coal must be further ground before entering the flotation machine to achieve a particle size suitable for flotation (typically 0. Particles smaller than 1 mm).
Flotation separation:
The ground coal powder is mixed with water to form a slurry. After adding flotation reagents (such as collectors, frothers, and modifiers), the slurry is fed into flotation cells. Through mechanical agitation and air injection, bubbles are generated. Coal particles attach to the bubbles and rise to the surface of the slurry, forming a froth layer. The froth layer is collected to obtain high-purity clean coal.
6. Clean Coal Processing
Dewatering:
After coal preparation methods such as jigging, heavy medium separation, or flotation, the resulting clean coal contains a certain amount of moisture. Dewatering equipment (e.g., dewatering screens, centrifuges, or filter presses) is used to reduce moisture content and improve the quality of the clean coal.
Storage and Transportation:
Dewatered clean coal is stored and transported. To prevent moisture absorption and spontaneous combustion during storage and transportation, protective measures should be implemented, such as storing in coal sheds or enclosed stockyards. Tailings Management
Tailings Discharge:
Tailings (mainly gangue and impurities) generated during jigging, dense medium, and flotation coal preparation processes are discharged via discharge equipment to the tailings management area.
Tailings Dewatering and Wastewater Treatment:
Moisture contained in the tailings must be further processed. After dewatering using thickeners or filters, solid tailings are either stockpiled or subjected to further treatment. Wastewater generated during the flotation process is treated for recycling or for compliant discharge, minimizing environmental pollution. Environmental Protection and Safety Measures
Environmental Protection Measures:
Coal preparation plants should implement environmental protection measures such as dust control and wastewater treatment to minimize environmental impacts. Treated wastewater can be recycled or discharged in compliance with regulatory standards, reducing water resource consumption.
Safety Measures:
Establish and enforce safety production regulations, conduct regular safety inspections and training, and equip the facility with protective devices and emergency response systems to ensure worker safety.
Process Description
Thermal coal refers to coal used as a power feedstock. In a narrow sense, it generally refers to coal used for thermal power generation. In a broader sense, coal used for power generation, locomotive propulsion, boiler combustion, or other purposes to generate power is classified as power coal, commonly known as thermal coal.
Time period
2022
2026
Geography
China,Xinjiang Uygur Autonomous Region
Geography comment
Forming average data for Xinjiang through data integration from multiple sources
Macroeconomic value
Business-as-Usual
Data validation
Yes
Technology
Current Technology
Technology comment
Not specified