Espansione di un impianto di flottazione per oro da 2 milioni di t/a in Xinjiang, Cina

Upgraded Crushing & Screening:

• Integration of a new primary gyratory crusher to handle increased throughput.
• Existing two-stage crushing circuit (Jaw + Cone Crusher) optimized and retrofitted to form a robust three-stage crushing system, ensuring consistent feed size of 12mm below for grinding.

Circuito di flottazione migliorato:

• Installation of new, high-efficiency 200 m³ flotation cells to form an expanded circuit.
• Implementation of a “1-stage Rougher, 3-stage Cleaner, 2-stage Scavenger” configuration for superior selectivity and recovery.
• Introduction of an advanced automated reagent dosing system to optimize collector and depressant usage, particularly for controlling arsenic.

Controllo di Processo e Automazione:

• DCentralized PLC/DCS control system integrated with the existing plant control room.
• Addition of online particle size analyzers (PSD) and pH/ORP sensors for real-time process optimization, ensuring stable operation at the expanded capacity.

Grinding Circuit Expansion:

• Addition of a second Φ5.0m x 8.5m Ball Mill operating in parallel with the existing unit.
• Formation of a closed-circuit grinding system with hydrocyclones to achieve a target grind size of 80% passing 75µm, essential for liberating fine gold locked in sulfides.

Concentrate & Tailing Handling:

• New addensante ad alta velocità for flotation concentrate dewatering.
• Installation of a filter press for the concentrate to produce a low-moisture filter cake, reducing transportation costs.
• Upgraded tailing pumping system and pipeline to the existing tailings storage facility, designed to handle the increased volume.

Key Features & Outcomes of the Expansion:

• Capacity Leap: Successfully increased processing capacity by 800,000 t/a, achieving the 2 Million t/a target.
• Recovery Boost: Through finer grinding and optimized flotation, the overall gold recovery rate was significantly enhanced by 6.5%.
• Proven EPC Capability: Demonstrated strong capability in brownfield project execution, seamlessly integrating new systems with existing infrastructure with minimal disruption to ongoing production.
• Adapted to Refractory Ore: The flowsheet is specifically designed to tackle the challenges of refractory sulfide gold ores prevalent in the region.
• Emphasis on Eco-Efficiency: The expansion prioritized water recycling from the thickener overflow and dry tailing stacking where applicable, aligning with stringent environmental policies in Xinjiang.