Overview of Unit Processes in the Concentrator Circuit
The Morenci concentrator processes sulfide ores, utilizing multiple stages to liberate, concentrate, and separate copper and molybdenum. Each unit process, from crushing to flotation, plays a critical role in efficient recovery.
1. Primary Crushing
Process: Ore is transported from the mine to primary crushers, reducing the ore size for downstream processing. Primary crushers handle large chunks of ore, making it easier to manage and further crush.
Equipment: Includes jaw crushers and cone crushers for initial and secondary crushing.
2. Secondary and Tertiary Crushing
Process: After primary crushing, ore moves to secondary and tertiary crushers for finer particle size reduction.
Equipment: Cone crushers and sometimes hydraulic roll crushers (HRC) perform secondary reduction, enhancing copper and molybdenum mineral liberation.
3. Milling (Primary Grinding)
Process: Fine ore is fed to primary ball mills in closed circuit with spiral classifiers, reducing ore size further and liberating copper and molybdenum particles from gangue.
Equipment: Primary ball mills and spiral classifiers. Spiral classifiers segregate coarse and fine particles for additional grinding or flotation.
4. Cyclone Classification
Process: Cyclone classifiers separate finer particles from coarser particles in mill discharge. Coarse particles return to ball mills, while fine particles proceed to flotation.
Purpose: Ensures optimal particle size distribution for flotation.
5. Rougher Flotation
Process: Chemicals are added to create bubbles that adhere to copper and molybdenum particles, lifting them to the surface and separating them from gangue.
Outcome: Rougher concentrate advances to regrind mills for additional size reduction and purification.
6. Regrinding Mills
Process: Rougher concentrate undergoes regrinding to increase particle surface area, enhancing cleaner flotation.
Equipment: High-energy regrind mills achieve the fine grind needed for effective cleaner flotation.
7. Cleaner Flotation
Process: Concentrate passes through cleaner flotation stages to remove impurities and further concentrate copper and molybdenum.
Stages: Multiple cleaner stages produce higher-grade concentrate with cleaner tailings that can be recirculated.
8. Copper/Molybdenum Separation Circuit
Process: Copper/molybdenum concentrate enters a specialized flotation circuit for metal separation, with flotation conditions adjusted for selective copper or molybdenum flotation.
Products: Copper concentrate and molybdenum concentrate, both thickened and filtered before off-site transport.
9. Thickening and Filtration
Thickening: Tailings and concentrates from flotation are thickened for water recovery, recycled back to the concentrator to enhance water efficiency.
Filtration: Filtered copper and molybdenum concentrates are stored for later transportation.
10. Tailings Management
Process: Flotation tailings are thickened and pumped to tailings storage facilities, where process water is recovered and recycled for sustainability.
