Cradle to Gate
Identity ID
b8a3c8bd-6e81-4acf-9bcf-9962ed00518d
Materials
Associated ID
fc2bcf11-d3d5-4e6e-b345-2d2b31d1da03
Included activities starts
Included activities ends
Description
This dataset represents the processing of magnetite in China using ultra-fine crushing and wet magnetic separation with tailings rejection technology. It provides a life cycle inventory (cradle-to-gate) covering all activities associated with iron concentrate beneficiation production, from crushing to the output of iron concentrate, but excluding direct or indirect greenhouse gas emissions from the production of crushing equipment, magnetic separation equipment, personnel commuting, and daily office operations during the beneficiation process. The dataset was compiled from multiple data sources based on national standards such as the 'Manual of Production and Emission Coefficients for the Iron Ore Mining and Processing Industry (0810)', 'Emission standard of pollutants for mining and mineral procressing industry (GB 28661-2012)', 'Cleaning production standard Iron ore mining and mineral processing industry', and 'The norm of the energy consumption per unit product of iron ore dressing(GB31337-2014)', and represents the average production level of ultra-fine crushing - wet magnetic separation tailings rejection technology for magnetite processing in China.
Activity Description
This dataset describes the ultrafine crushing-wet magnetic separation tailings disposal technology for magnetite, with the following process flow:
1. Crushing Stage
Coarse Crushing: The ore undergoes coarse crushing using a jaw crusher, breaking large pieces into smaller particles, typically below 100mm.
Medium and Fine Crushing: The coarsely crushed ore enters a cone crusher or impact crusher for further crushing into even smaller particles, with the final particle size generally controlled between 5 and 15mm, preparing for the ultrafine crushing process.
2. Ultrafine Crushing (High-Pressure Roller Mill)
High-Pressure Roller Mill: The high-pressure roller mill is the core equipment in the ultrafine crushing process. Under high pressure, the ore is crushed, refining the particle size to below 5mm or 3mm, achieving the particle size required for magnetic separation. The high-pressure roller mill not only performs physical crushing but also improves the ore's liberation degree by generating microcracks, reducing energy consumption and improving the efficiency of subsequent magnetic separation.
Ultrafine Crushing Effect: The ore particles are significantly reduced after high-pressure roller milling, the liberation degree is significantly improved, and the separation of iron minerals from gangue is more thorough. This particle size (typically -5mm or -3mm) ensures optimized magnetic separation performance.
3. Wet Magnetic Separation Tailings Removal
Wet Magnetic Separation Equipment: The wet magnetic separation process uses a permanent magnet medium-intensity magnetic separator. This equipment separates iron minerals from gangue through magnetic separation. Magnetic minerals are adsorbed by the magnetic separator drum, while non-magnetic gangue is discharged as tailings.
Tailings Removal Effect: Wet magnetic separation can remove approximately 40% of the coarse tailings, significantly reducing the amount of material entering subsequent grinding and beneficiation processes. This not only reduces energy consumption and costs but also effectively improves beneficiation efficiency. The iron content of the tailings is typically controlled below 10%, while the iron grade of the iron concentrate is increased to over 65%.
4. Concentrate Recovery and Tailings Treatment
Grinding Processing: After wet magnetic separation tailings removal, the iron grade of the mineral material entering the grinding process is significantly increased to around 40%, providing high-quality raw materials for subsequent grinding and beneficiation processes. The grinding process further improves the concentrate grade through grinding and multi-stage magnetic separation. Concentrate beneficiation and dewatering: The beneficiated iron concentrate is further purified by magnetic separation, ultimately achieving an iron concentrate grade of over 65% and SiO₂ content controlled below 4%. Dewatering equipment (such as disc filters) dewaters the slurry, ultimately forming iron concentrate with low water content, facilitating transportation and storage.
Tailings treatment: The tailings generated from the tailings disposal process have a low iron content (usually below 10%). After treatment in tailings ponds or other facilities, the tailings are either landfilled or disposed of as other waste, reducing pressure on tailings ponds and mitigating environmental impact.
Process Description
The iron concentrate in this dataset has a grade of 65%, belongs to transition metals, and is the primary product of the mineral processing stage. Iron concentrate is typically in powder form and is widely used in downstream processing operations at sintering and pelletizing plants, serving as a key raw material in steel production.
Time period
2022
2026
Geography
China
Geography comment
Forming China's average data through merging multiple provincial datasets
Macroeconomic value
Business-as-Usual
Data validation
Yes
Technology
Current Technology
Technology comment
Technical principle of ultra-fine crushing-wet magnetic separation and tailings rejection technology: Crush ore into ultra-fine particles below 5 mm or 3 mm using a high pressure roller mill, followed by wet magnetic separation and tailings rejection using a medium-intensity permanent magnetic separator. Technology applicability and characteristics: The ultra-fine crushing-wet magnetic separation and tailings rejection technology can improve metal recovery rates and reduce pollution at the source. By applying this technology, approximately 40% of coarse tailings can be rejected, increasing the iron grade of material fed into grinding to about 40%, producing iron concentrate with an iron grade above 65% and SiO2 content reduced to below 4%, while keeping tailings grade under 10%. However, this technology requires a high degree of automation control. This technology is widely applicable to both existing and newly built magnetite mines, especially suitable for extremely lean ores.