Molybdenum ore beneficiation process and practical application

First, Overview of molybdenum ore

As a key strategic resource, molybdenum has an irreplaceable role in metallurgy, chemical industry, aerospace and other fields. The core of its beneficiation process lies in the efficient extraction of molybdenite - the most widely distributed mineral in nature with the highest economic value. Based on the characteristics of molybdenum ore and industrial practice, this paper systematically introduces the framework of single molybdenum ore and copper-molybdenum ore beneficiation process, to provide technical reference for the industry.

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Second, a single molybdenum ore beneficiation process framework

1. Typical process: multi-stage regrinding and high-precision selection 

Roughing stage: the raw ore is roughly ground to -200 mesh, accounting for about 70% of the total, rapid flotation recovery of highly floatable congeners, reducing the subsequent load. 

- Regrinding and dissociation: regrind the rough concentrate to -325 mesh accounting for 90%, fully dissociate the inclusions.

- Deep flotation: implement 8~10 times of selection + fine sweeping, gradually remove impurities.

2. Pharmaceutical system

- Capture agent: non-polar oil (e.g. paraffin), compounded sulfur-hydrogen-based agent (e.g. butylated yellow agent). 

- Foaming agent: Methyl Isobutyl Methanol (MIBC), Pineol oil. 

- Process optimisation: emulsified hydrocarbon oil (octinoxate) enhances the roughing efficiency, and YC-111 new type of foaming agent can improve the recovery rate by 8.44%.

3. Typical cases

- Jinduicheng Baihua Ling Concentrator (Asia's largest): 25,000 tonnes of raw ore per day, one stage of grinding and then flotation, 8 times of selection to obtain 53% concentrate, total recovery rate of 85%~87%. 

- Claymakers concentrator in the United States: five-stage selection process, concentrate grade of 54%, three times regrinding to accurately control the particle size to -20μm accounted for 80%.

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Third, copper and molybdenum coeval ore beneficiation process

1. Process route: mixed flotation - separation and extraction

- Mixed rougher flotation: collector (flavouring agent) + foaming agent combined, simultaneous recovery of copper and molybdenum minerals. 

- Separation key: inhibit copper minerals (chalcopyrite), flotation pyroxene molybdenite. 

2. Copper and molybdenum separation technology 

- Conventional flotation: sodium sulphide inhibitor removes copper mineral surface trap layer.

- Nitrogen-filled flotation: Inert environment slows down the oxidation of sodium sulphide and reduces the amount of chemicals used by 75% (Benefit case of Pima Concentrator, USA). 

- Magnetic separation: Using the weak magnetic property of chalcopyrite, non-magnetic pyromolybdenite is separated by pulsating high gradient magnetic separation. 

3. Typical cases

- Chile Chuquicamada Concentrator (the world's largest copper and molybdenum plant): adopting three stages of regrinding + five times of concentration, with a copper concentrate grade of 42% and a molybdenum recovery rate of 40%. 

- La Caridad Concentrator, Mexico: 24 hours of slurry passivation to enhance copper mineral suppression and eight concentrates to obtain 58% molybdenum concentrate.

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Fourth, Innovative processes for difficult-to-treat molybdenum ores

1. Molybdenum oxide ore treatment

- Adaptation of trapping agent: RJT selective trapping agent with Na₂CO₃ adjusts pH, and the concentrate grade is increased to 23.6%. 

- Leaching joint process: sodium hypochlorite decomposition + ion exchange, the recovery rate of all wet process reaches 85%. 3

2. Nickel-Molybdenum Ore Resourcing

- Roasting - leaching: 600℃ desulphurisation + alkaline leaching to extract molybdenum, leaching rate nearly 100%. 

- Processing and metallurgy synergistic: acid leaching extraction/alkali leaching ion exchange to produce molybdate, reduce tailings molybdenum residue to below 1.5%.

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Fifth Technology Trends and Challenges

1. Environmental transformation: cyanide / Knox chemicals are gradually phased out, nitrogen filling process and non-toxic inhibitor R & D has become the focus.

2. Fine control: automated grinding and classification system + dynamic optimisation of flotation parameters to reduce over-grinding losses.

3. Comprehensive utilisation of resources: development of complex polymetallic ore dressing-metallurgy joint process, enhancement of molybdenum and nickel and other synergistic recovery benefits.

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Conclusion

Molybdenum ore beneficiation is based on flotation as the core, through process optimisation and technological innovation to cope with the challenges of low-grade and complex symbiosis. In the future, we need to further develop green chemicals and intelligent control technology to promote the efficient and sustainable development of molybdenum resources.