Cradle to Gate
Identity ID
8964dc61-ccc2-413c-b2a0-dfb5749394f1
Materials
Associated ID
ad42cb41-07a7-42ef-abda-6c68126bde52
Included activities starts
Included activities ends
Description
This dataset represents a life cycle inventory (cradle-to-gate) for the entire process of coal preparation from a combined jigger-flotation coal beneficiation system to the production of clean coal. It covers all activities related to coal washing, but excludes external factors beyond the coal preparation plant (such as raw coal mining and the use of clean coal), as well as direct or indirect greenhouse gas emissions arising from personnel commuting and daily office operations during the coal preparation process. Based on Chinese national standards such as "Clean Production Standard for the Coal Mining and Washing Industry" (HJ 446-2008) and "Emission Standards for Pollutants from the Coal Industry", this dataset was compiled from multiple data sources and is representative of the average production level in China.
Activity Description
This dataset describes the combined jigging and flotation coal beneficiation process, which integrates both jigging and flotation methods, primarily used for processing coal of different particle sizes and qualities to achieve optimal separation efficiency. Below is a detailed description and introduction of the entire production process for combined jigging and flotation coal beneficiation:
1. Raw Coal Preparation
Coal Crushing and Screening:
Raw coal is first crushed by crushers into particles suitable for jigging and flotation. Generally, coarse-sized coal (above 50 mm) will undergo jigging separation, while fine-sized coal (0.5–50 mm) and slimes (below 0.5 mm) are treated by flotation. are then subjected to flotation separation. The crushed coal is classified by particle size using screening equipment, and coal of different sizes is sent to the corresponding coal preparation equipment. 2. Jigging Separation
Jig Preparation:
Coarse and medium-sized coal is separated using a jig. The jig employs pulsating water to stratify coal from impurities based on density. The lighter clean coal rises to the upper layer, while the heavier gangue and impurities sink to the lower layer.
Separation Process:
The coal enters the feed hopper of the jig and mixes with water to form a slurry. Under the action of the jig, the clean coal and impurities become stratified. The clean coal is collected via an overflow chute or discharge device, while the impurities are discharged through the discharge outlet. Flotation separation
Grinding:
Coarse and fine coal particles need to be further ground before entering the flotation machine, to achieve a suitable particle size for flotation (typically below 0.1 mm).
Flotation reagent addition:
The ground coal powder is mixed with water to form a slurry, and flotation reagents (such as collectors, frothers, and modifiers) are added before being fed into the flotation cell.
Flotation process:
Inside the flotation cell, bubbles are generated through mechanical agitation and air injection. Coal particles attach to the bubbles and rise to the surface of the slurry, forming a froth layer. This froth layer is collected to obtain high-purity clean coal. Clean coal processing
Dewatering:
After jigging and flotation coal preparation, the clean coal contains a certain amount of moisture and needs to be dewatered using dewatering equipment (such as dewatering screens, centrifuges, or filter presses) to reduce moisture content and improve the quality of clean coal.
Storage and transportation:
The dewatered clean coal is stored and transported. To prevent moisture absorption and spontaneous combustion during storage and transportation, protective measures must be taken, such as storing in coal sheds or sealed stockyards. Tailings Management
Tailings Discharge:
The tailings generated during jiggering and flotation processes (mainly gangue and impurities) are discharged through discharge equipment and transported to the tailings management area.
Tailings Dewatering and Wastewater Treatment:
The moisture in the tailings requires further processing. 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 discharged in compliance with environmental standards, minimizing environmental pollution.
Process Description
Cleaned coal refers to high-quality coal that has been processed in a coal washing plant, reducing ash and sulfur content and removing certain impurities, making it suitable for specific applications.
Time period
2022
2026
Geography
China
Geography comment
Forming China's average data through merging data from multiple sources.
Macroeconomic value
Business-as-Usual
Data validation
Yes
Technology
Current Technology
Technology comment
Jigging and flotation combined coal washing is an efficient and flexible coal preparation process that effectively handles coal of different particle sizes and qualities by combining jigging and flotation methods. Its production process includes coal crushing and screening, jigging separation, grinding, flotation separation, clean coal processing, and tailings management. This process significantly improves coal purity and utilization efficiency, offering high processing capacity, high separation efficiency, and environmental friendliness, and is widely applied in coal preparation plants.