In the mining industry, long-term partnerships are established through consistent project delivery and reliable plant operational performance. This principle is exemplified by Xinhai Mining’s continued cooperation with a gold producer in West Asia. Following the successful completion of a 500 t/d cyanidation plant, Xinhai was reselected to undertake the client’s 1,200 t/d expansion project—which is currently operating at a capacity exceeding its design specifications.
This project embodies the practical application of Xinhai’s EPC+M+O services for gold processing plants, with a focus on controlled project execution, rapid ramp-up to full capacity, and sustained stable operation.
The expansion project is built upon an oxide gold processing plant initially delivered by Xinhai in 2020. The Phase I plant, designed with a throughput of 500 t/d, was completed and commissioned within one year. On-site technical support was promptly provided to effectively resolve installation and start-up challenges, ensuring the absence of major project delays.
(Gold Plant Expansion to 1,200 t/d in West Asia)
Post-commissioning, the Phase I plant operated at a throughput of 600 t/d, surpassing its design capacity while maintaining stable gold recovery rates. Importantly, the plant demonstrated excellent operability and maintainability under on-site conditions, which laid a solid foundation for consistent production performance and the client’s decision to proceed with Phase II.
The expansion project processes oxide gold ore with an average grade of 1.2 g/t, with a designed throughput of 1,200 t/d. Xinhai delivered a fully integrated engineering package encompassing all critical components required by the client:
Process design and construction drawings
Fine ore storage, grinding, leaching, and adsorption systems
Thickening and tailings dewatering
Desorption and electrowinning
Supporting systems (water supply, drainage, power distribution, civil works, and plant layout)
Throughout the project lifecycle, Xinhai provided comprehensive installation guidance and commissioning support to ensure the smooth progression of all work stages.
The adopted process flowsheet is proven and operationally robust, adhering to the following sequence: Crushing → Grinding & Classification → Cyanide Leaching → Carbon Adsorption → Desorption & Electrowinning → Gold Tailings Dewatering Solutions. The design prioritizes operational stability, controllability, and maintainability, avoiding unnecessary process complexity.
Xinhai’s engineering strategy focused on practical upgrades derived from on-site conditions and operational experience gained from Phase I, rather than relying on standardized templates.
1.Maximizing existing infrastructure
The original crushing circuit was retained to minimize capital expenditure and shorten the construction schedule. Additional conveyors were installed to connect the existing circuit to the new fine ore bin, achieving cost-effectiveness and efficiency.
2.Stable grinding and classification
A two-stage closed-circuit grinding system was implemented to ensure consistent particle size control, which is critical for optimizing downstream process performance:
Ball mill + classifier (primary stage)
Ball mill + hydrocyclone (secondary stage)
3.Leaching system upgrade
The leaching tanks were upgraded to a 10-stage circuit, providing a total ore residence time of 26 hours. High-pressure Roots blowers were introduced to maintain adequate dissolved oxygen levels, thereby enhancing leaching kinetics and overall gold recovery performance.
4.Carbon adsorption and recovery
Gold recovery was achieved through carbon-in-leach (CIL) process, which transfers dissolved gold onto activated carbon. The loaded carbon was subsequently processed via desorption, electrowinning, and smelting to obtain the final gold product.
5.Tailings management
Tailings were dewatered using filter presses, producing low-moisture filter cake for transportation to the tailings storage facility. This approach improves handling efficiency and ensures compliance with environmental regulations.
✧Throughput above design capacity
The plant, designed for a throughput of 1,200 t/d, is currently operating stably at 1,500 t/d. This additional production capacity is achieved without significant modifications to the installed system, delivering enhanced value to the client.
✧Improved operating efficiency
Targeted optimizations were implemented to enhance operating efficiency, including:
✧Grinding fineness optimization: Adjustments were made based on ore characteristics to balance gold recovery rates and throughput, avoiding a one-size-fits-all approach.
✧Return sand handling improvement: Classifier-based return systems replaced steep-angle conveyors, reducing material spillage, improving plant cleanliness, and enhancing operational safety.
✧Efficient tailings dewatering: A squeeze and backwash filter press was employed to improve solution recovery and reduce tailings moisture content, optimizing water utilization and disposal efficiency.
These incremental improvements collectively contribute to reduced operating costs per tonne and more stable plant performance.
✧Expansion Without Production Interruption
Maintaining continuous production during the expansion phase was a key requirement for the client, as unplanned downtime would result in significant losses. To address this, Xinhai implemented coordinated engineering measures, including:
Optimized piping layouts to avoid disrupting existing operations
Increased diameters in key leaching pipelines to accommodate higher flow rates
Modified drum screens to enhance handling capacity
These measures enabled the expansion work to proceed without interrupting the plant’s normal operations, ensuring production continuity. Additionally, extra fresh water storage capacity was added to stabilize the water supply, guaranteeing consistent plant operation under on-site conditions.
✧Consistent Delivery Across Project Phases
This project demonstrates that strong performance in the initial phase of a project can effectively reduce risks associated with subsequent expansions. Design decisions for Phase II were based on actual operational data from Phase I, rather than theoretical assumptions.
Xinhai’s contribution extended beyond engineering design and equipment supply. Responsive on-site support and practical problem-solving ensured the stable execution of the project throughout its entire lifecycle. The core of Xinhai’s approach remains unchanged: practical solutions, reliable delivery, and long-term operational support.
Through its EPC+M+O model, Xinhai Mining provides integrated solutions covering the full lifecycle of mineral processing projects—from initial construction to expansion and ongoing optimization. The West Asia gold plant expansion project exemplifies a repeatable approach: combining proven process designs with site-specific engineering decisions to deliver stable, scalable production performance that meets the client’s long-term needs.
Share your project details and our engineers will get back to you shortly.
CHAT
MESSAGE
