Cradle to Gate
Identity ID
878891a8-31c5-45aa-98a4-7ec78bf27e00
Materials
Associated ID
d7ecd423-f863-4480-a859-7051f0a1d79d
Included activities starts
Included activities ends
Description
This dataset represents the life cycle inventory (cradle-to-gate) of hematite ore processing in Hebei, involving stage grinding, coarse-fine classification, and gravity separation-magnetic separation-anionic reverse flotation technology, covering all activities related to iron concentrate production from the crushing stage onward. It excludes direct or indirect greenhouse gas emissions associated with the production of crushing and magnetic separation equipment, personnel travel, and daily office operations during the mineral processing. 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)', representing the average production level of Hematite processing in Hebei using staged grinding, coarse-fine separation, and gravity-magnetic-reverse anionic flotation technology.
Activity Description
This dataset describes the process of treating hematite using staged grinding, coarse and fine separation, gravity-magnetic separation-anion reverse flotation technology. The process flow is as follows:
1. Staged Grinding
Process Description:
First Stage Grinding: After crushing, the ore first enters the first stage grinding equipment (usually a ball mill or rod mill). The grinding fineness is controlled at **70%~80% -0.074mm**, ensuring effective liberation of larger mineral particles and sufficient crushing of coarse minerals, creating conditions for subsequent separation processes.
Second Stage Grinding: The material after coarsening enters the second stage grinding, further refining the mineral particles. The fineness is typically controlled at **over 90% -0.074mm**, ensuring sufficient liberation of fine minerals and resulting in better separation of fine minerals.
Results: Through two-stage grinding, the degree of mineral particle liberation is significantly improved, ensuring effective separation of minerals in subsequent beneficiation processes and improving concentrate recovery.
2. Coarse and Fine Separation
Process Description: After grinding, the ore pulp is classified using screening equipment to separate coarse and fine minerals:
Coarse Minerals: Coarse minerals are fed into the subsequent gravity separation-magnetic separation-acidic direct flotation process.
Fine Minerals: Fine minerals are fed into the continuous grinding-magnetic separation-anion reverse flotation process.
Effect: Coarse and fine separation effectively improves separation efficiency, allowing coarse and fine minerals to undergo different treatments, thereby optimizing subsequent beneficiation results.
3. Gravity Separation-Magnetic Separation-Acidic Direct Flotation of Coarse Minerals
Process Description:
Gravity Separation: Coarse minerals are first pre-separated using gravity separation equipment (such as jigs or spiral concentrators), utilizing density differences to separate high-density iron minerals.
Magnetic Separation: The gravity-separated ore pulp enters magnetic separation equipment for further separation, separating magnetic iron minerals, enriching the concentrate, and removing more gangue.
Acidic Direct Flotation: The magnetic concentrate is then further refined using acidic direct flotation, where acidic flotation reagents float gangue minerals while iron minerals settle and are recovered. Results: Through the combination of gravity and magnetic separation, the grade of coarse iron ore is significantly improved. Acidic direct flotation further enhances the purity of the concentrate, controlling the SiO₂ content below 4%, and achieving an iron concentrate grade of 64%–67%.
4. Continuous Grinding-Magnetic Separation-Anion Reverse Flotation for Fine-Grained Minerals
Continuous Grinding: Fine-grained minerals enter a continuous grinding system for further particle refinement, ensuring complete liberation of iron minerals from gangue minerals. The grinding fineness is typically controlled to be over 90% **-0.074 mm**.
Magnetic Separation: The ground slurry enters a magnetic separator to separate strongly magnetic iron minerals, initially enriching the iron concentrate and removing most gangue minerals.
Anion Reverse Flotation: Magnetic concentrate then enters the anion reverse flotation system. By adding anion collectors (such as fatty acid reagents), gangue minerals are selectively floated, while iron minerals settle and are recovered as concentrate.
Effects: Through the combination of continuous grinding and magnetic separation-anion reverse flotation, the grade of fine-grained iron concentrate can be increased to 64%~67%, with an iron recovery rate exceeding 90%. The iron content in the tailings is low, and the tailings grade can be reduced to below 11%.
5. Tailings Treatment and Concentrate Recovery
Tailings Treatment: The iron content of the tailings after flotation is usually below 11%. After treatment in tailings ponds or dry discharge technology, it can be used for backfilling or other environmentally friendly disposal methods.
Concentrate Dewatering: The iron concentrate after flotation enters a ceramic filter or other high-efficiency filtration equipment for dewatering, reducing the moisture content of the concentrate (usually controlled below 10%), facilitating subsequent transportation and storage.
Process Description
The iron concentrate in this dataset has a grade of 66%, belongs to transition metals, and is the primary product of the mineral processing stage. Typically in powder form, iron concentrate is widely used in downstream processing operations at sintering and pelletizing plants, serving as a key raw material for steel production.
Time period
2022
2026
Geography
China,Hebei
Geography comment
Forming Hebei average data through merging multiple datasets
Macroeconomic value
Business-as-Usual
Data validation
Yes
Technology
Current Technology
Technology comment
Stepwise grinding, coarse-fine particle separation, and a combination process of gravity separation-magnetic separation-anionic reverse flotation refers to the application of stage grinding, coarse-fine separation, and gravity separation-magnetic separation-acidic direct flotation for the coarse particle fraction; while for the fine particle fraction, continuous grinding followed by magnetic separation-anionic reverse flotation is employed. Applicability and characteristics of the technology: This technology enables full utilization of resources, relatively reduces mining volume, and reduces pollution at the source. Implementing this technology can produce iron concentrate with a grade of 64%--67%, tailings grade below 11%, and SiO₂ content below 4%. The technology is applicable to non-quartz gangue hematite ores or lean hematite ores in the Anshan region.