Project Overview
A local Mongolian mining operator planned to build a new gold beneficiation plant to expand production capacity. The client encountered multiple operational bottlenecks, including fluctuating ore grades, unreasonable process layout and insufficient in-house operational experience. To resolve these issues and optimize capital input and profit output, the client partnered with Zhongyi. We delivered a full EPC+M+O turnkey solution for a 1000TPD customized Gold Processing Plant. The full package covers ore testing, process design, complete equipment supply, site commissioning and daily mine operation management. During project execution, we focused on cost control, worker safety, eco-friendly production and circular utilization to maximize the recovery of free gold and dissolved gold from raw ore.
Project Challenges
- No applicable beneficiation process matching local gold ore characteristics, restricting gold recovery efficiency;
- Disordered equipment collocation led to high power consumption and unstable production;
- The on-site team lacked standardized operating and maintenance experience for large-scale mineral processing lines;
- Local environmental policies put forward strict requirements on cyanide emission control and tailings water recycling.
Customized Solution & Service Support
Based on ore analysis and site survey, Zhongyi configured a mature combined processing flow of gravity separation and cyanide leaching for this Gold Ore Processing Plant. Beyond equipment supply, we provided one-stop full-cycle services including process simulation, plant layout optimization, staff operational training and long-term after-sales support. This complete solution helped the client realize stable low-cost production while meeting local environmental compliance standards.
Beneficiation Process & System Equipment Configuration
The entire processing line consists of four core sections: crushing and screening, grinding and classification, ore separation, as well as tailings dewatering.
1. Crushing & Screening (Three-stage One Closed-circuit)
This closed-circuit crushing design is used to produce qualified fine ore with uniform particle size, eliminating oversize particles to reduce grinding pressure.
- Primary Crushing: Run-of-mine ore is coarsely crushed by jaw crusher, then delivered via belt conveyor to circular vibrating screens for primary screening;
- Secondary Crushing: Oversized materials (+30mm) from the upper screen deck are sent to another jaw crusher for medium crushing;
- Tertiary Crushing & Closed Circuit: Materials sized 15-30mm and 8-15mm are stored in a surge bin and fed into a cone crusher through a vibrating feeder for fine crushing. All crushed materials are transported to the secondary circular vibrating screen. Particles larger than +8mm are re-screened by a bar screen; +20mm materials return to tertiary crushing, while 8-20mm materials flow back to the surge bin to form a closed circulation. Final qualified fine ore (-8mm) is transferred to the grinding workshop.
2. Grinding & Classification (Two-stage Closed-circuit)
Dual closed-circuit grinding technology maintains optimal grinding fineness, effectively preventing over-grinding and under-grinding to improve separation performance.
- Primary Grinding: Qualified fine ore is processed by an energy-saving overflow ball mill. Discharged -3mm slurry is pumped to hydrocyclones for classification; underflow materials return to the ball mill for regrinding to form primary closed circulation;
- Secondary Grinding: Hydrocyclone overflow from the first stage flows into the separation section. Gravity separation tailings are pumped to secondary hydrocyclones. The underflow mixes with oversize materials from the cylindrical screen and enters the secondary overflow ball mill, forming a complete secondary closed-circuit grinding system.
3. Mineral Separation System
3.1 Gravity Separation
Hydrocyclone overflow from primary grinding is delivered to centrifugal concentrators for roughing gold separation. Concentrates from multiple centrifugal units are upgraded by shaking tables, and high-purity granular gold products can be directly sent for smelting. Tailings generated from shaking tables and centrifugal concentrators are collected for secondary grinding and reprocessing.
3.2 Cyanide Leaching
Slurry overflow from secondary grinding passes through linear debris screens to remove impurities like wood chips, then thickened to 40%-45% solid content in a pre-leaching thickener. The concentrated slurry is pumped to gradient-arranged leaching tanks for gravity-fed cyanidation. Sodium cyanide is added to each tank, and activated carbon is filled in the final tank to adsorb dissolved gold. Loaded gold carbon is transported between tanks by air lifters, and separated slurry flows back to the specified leaching tank for cyclic processing.
3.3 Desorption Electrolysis & Smelting
Gold-loaded carbon is processed in the desorption electrolysis system. Under stable working conditions of 150℃ and 0.5MPa, high-quality gold slime can be produced within 12 to 15 hours. The slime will be further smelted and refined into finished gold bullions.
4. Tailings Dewatering & Water Reuse
After gold leaching recovery, residual slurry is filtered by safety screens to intercept fine loaded carbon. The tailings are pumped to filter presses for pressure dewatering. Solid filter cakes are stacked in designated tailings ponds. The filtrate is disinfected with bleaching powder in buffer tanks and reused as industrial backwater for the whole beneficiation line, achieving zero discharge of production wastewater.
Project Specifications
| Parameter | Specification |
|---|---|
| Design Daily Processing Capacity | 1000 tons per day (TPD) |
| Crushing Closed-circuit Discharge Size | -8mm qualified fine ore |
| Pre-leaching Slurry Solid Density | 40% – 45% |
| Desorption Electrolysis Operating Conditions | 150℃ working temperature, 0.5MPa working pressure, 12-15h single batch processing cycle |
| Core Beneficiation Process Route | Three-stage one closed-circuit crushing + two-stage closed-circuit grinding + gravity separation + cyanide leaching + desorption electrolysis + tailings dewatering & water reuse |
| Main Equipment List | Jaw crusher, cone crusher, circular vibrating screen, bar screen, energy-saving overflow ball mill, hydrocyclone, centrifugal concentrator, shaking table, thickener, leaching tank, desorption electrolysis unit, filter press |
Project Results
This complete gold beneficiation plant consists of two major functional sections: mineral beneficiation and onsite smelting. After a full set of processing procedures including crushing, grinding, gravity separation, cyanide leaching and desorption electrolysis, the final finished product is high-grade gold bullion with purity over 95%. While delivering integrated EPC+M+O construction services for the hard rock gold processing line, Zhongyi attached great importance to ecological protection and sustainable resource utilization. We equipped the entire plant with a complete tailings dry stacking system and a closed-loop filtrate recycling system. The optimized green production design minimizes solid waste accumulation and reduces external freshwater consumption, enabling long-term, stable and eco-compliant high-quality operation for the whole gold extraction plant.
Client Feedback
“We chose Zhongyi due to their mature EPC+M+O mining service model. The customized complet Gold Processing Plant perfectly adapts to our ore features and desert-site operating conditions. The combined gravity and cyanide leaching process effectively boosted our overall gold recovery rate. In addition to reliable equipment, their on-site commissioning and professional training helped our team get started quickly. The recycled tailings water system also helps us easily meet local environmental regulations. We are satisfied with the stable daily output and economic returns.”
Get Custom Solutions
Looking for a dependable partner to build a high-performance gold beneficiation plant? Zhongyi provides tailor-made Gold Processing Plant solutions including ore feasibility testing, process design, equipment manufacturing, on-site installation and lifelong after-sales services. Feel free to contact our technical team to acquire a customized beneficiation flowchart and detailed budget quote.
