Cradle to Gate
Identity ID
35b20fbe-300d-4ec0-8c80-5faeb3ade328
Materials
Associated ID
e9683e6c-5d68-4382-981f-bdbc59032c28
Included activities starts
Included activities ends
Description
This dataset represents the life cycle inventory (cradle-to-gate) of coal preparation starting from jigging and flotation combined processes to the production of Coking clean coal, covering all activities associated with coal washing, but excluding external conditions beyond the coal preparation plant (such as raw coal mining, utilization of the Clean coal), as well as direct or indirect greenhouse gas emissions from employee commuting and daily office operations during the coal washing process. The dataset is based on national standards, including the "Cleaner Production Standard for the Coal Mining and Preparation Industry" (HJ 446-2008) and the "Emission Standards of Pollutants for the Coal Industry", and is compiled from multiple data sources, representing the average production level in Shanxi province.
Activity Description
This dataset describes combined jigging and froth flotation coal preparation, a process that integrates both jigging and froth flotation methods, primarily used for treating coals of different sizes and qualities to achieve optimal separation efficiency. Below is a detailed description and introduction of the entire production process of combined jigging and flotation coal preparation:
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. are then subjected to flotation separation. The crushed coal is classified by particle size using screening equipment, and coal of different particle sizes is sent to the corresponding coal beneficiation equipment. 2. Jigging Separation
Jig Preparation:
Coarse and medium-sized coal is separated using a jig. The jig utilizes pulsating water to stratify coal and 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:
Coal enters the feed hopper of the jig and mixes with water to form a slurry. Under the action of the jig, clean coal and impurities are stratified; the clean coal is collected through an overflow chute or discharge device, while impurities are discharged through a tailings outlet. Flotation Separation
Grinding:
Coarse and fine coal particles need further grinding before entering the flotation machine to achieve a suitable size for flotation (typically below 0.1 mm).
Flotation Reagent Addition:
The ground coal powder is mixed with water to form a slurry. After adding flotation reagents (such as collectors, frothers, and modifiers), it is 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. Coking coal processing
Dewatering:
After jigging coal preparation and froth 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:
After dewatering, the clean coal is stored and transported. To prevent moisture absorption and spontaneous combustion during storage and transportation, protective measures are required, such as using coal sheds or sealed stockyards for storage. Tailings Management
Tailings Disposal:
The tailings generated during jigging and flotation processes (primarily gangue and impurities) are discharged via discharge devices to a designated tailings management area.
Tailings Dewatering and Wastewater Treatment:
The moisture contained in the tailings is further treated through thickeners or filters for dewatering. The solid tailings are then stockpiled or subjected to further processing. Wastewater generated during the flotation process is treated for recycling or discharged in compliance with environmental standards, thereby minimizing environmental pollution.
Process Description
Coking coal in Shanxi Province is widely distributed in the Taiyuan Formation and the Shanxi Formation. The Taiyuan Formation includes gas coal, fat coal, coking coal, lean coal, and gas-fat coal, while the Shanxi Formation includes gas coal, fat coal, coking coal, and lean coal. For raw coal from the Taiyuan Formation, ash content ranges from 6.95% to 37.97%, volatile matter from 9.6% to 41.01%, maximum thickness of the vitrinite layer from 0 to 40 mm, total sulfur from 0.68% to 5.97%, and the net calorific value on an as-received basis (Qnet,ar) from 7712 to 9078 kcal/kg. For raw coal from the Shanxi Formation, ash content ranges from 16.53% to 34.33%, and volatile matter from 13% to 40%. 0.03%, the maximum thickness of the vitrinite layer ranges from 0 to 75 mm, and the net calorific value on an as-received basis (Qnet,ar) ranges from 7400 to 8660 kcal/kg.
Time period
2022
2026
Geography
China,Shanxi
Geography comment
Forming Shanxi'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.