Wholesale 500 TPH Gold Mining Washing Plant: HighCapacity Alluvial Processing Solutions

The Operational Challenge: When Your Feed Rate Outpaces Your Plant Capacity

Every hour your gold recovery circuit operates below 500 tons per hour (TPH), you are leaving recoverable gold in the tailings. For a midtier alluvial operation processing 4,000 tons per day, a 10% efficiency loss translates to approximately 14–18 ounces of unrecovered gold per week—at current market rates, that is a recurring cost of $35,000 to $45,000 in lost revenue, every single week.

Plant managers in the alluvial gold sector face a specific set of constraints that directly impact profitability:

• Feed variability: Claybound material, oversized cobbles, and highmoisture content can reduce effective throughput by 20–30% if the washing circuit lacks sufficient scrubbing energy and screening area.
• Water management: Inefficient water recirculation systems increase makeup water demand by up to 40%, raising operational costs and complicating environmental compliance in waterconstrained regions.
• Downtime accumulation: A washing plant that requires 4–6 hours of weekly maintenance for screen changes, pump servicing, and chute cleaning loses 2–3% of annual operating time—a direct hit to your production budget.
• Mobilization complexity: For contractors moving between sites, a plant that requires 15+ truckloads and 10 days for assembly extends nonrevenue periods significantly.

Does your current washing plant deliver consistent 500 TPH throughput on abrasive, clayladen feed? Can your operation maintain recovery efficiency while processing material with 30%+ clay content? Is your plant design optimized for rapid relocation and minimal civil works?

Product Overview: The 500 TPH Alluvial Gold Washing Plant

This equipment is a modular, highcapacity rotary trommel washing plant engineered specifically for alluvial gold recovery at a nominal feed rate of 500 TPH. The system integrates feed hopper, hydraulicdriven rotary scrubber, multideck vibrating screen, and integrated sluice or centrifugal concentrator recovery circuit into a single, transportable processing train.

Operational Workflow

1. Feed Loading: A heavyduty grizzly feed hopper (with hydraulic tipping grid) accepts direct loading from 50ton haul trucks. The 25 m³ hopper capacity absorbs loader surge, maintaining steady feed to the scrubber.
2. Primary Washing & Scrubbing: Material enters a 2.4 m diameter × 7.5 m long rotary scrubber with 18 mm AR400 steel liners. Highenergy tumbling action (12–14 RPM) breaks down clay agglomerates and liberates gold particles from gangue material.
3. Screening & Classification: Discharge from the scrubber passes over a doubledeck vibrating screen (2.4 m × 6.0 m). Oversize (+50 mm) reports to a radial stacker; intermediate fraction (−50 mm + 6 mm) is rejected or routed to secondary processing; undersize (−6 mm) feeds the recovery circuit.
4. Gold Recovery: The −6 mm fraction is distributed across a 2stage sluice run (12 m total length) with expanded metal and miners moss, or alternatively directed to a bank of 6 × 20inch Knelsontype centrifugal concentrators for highergrade feed applications.
5. Tailings Management: Tailings from the recovery circuit are dewatered via a cyclone cluster and discharged to a lined tailings dam or drystack system, with process water returned to the plant's 1,200 m³/hr recirculation system.

Application Scope

This plant is suitable for:

• Alluvial gold deposits with clay content up to 35%
• Feed material with particle size up to 600 mm
• Operations at altitudes up to 4,000 m (with derating above 3,000 m)
• Ambient temperatures from −10°C to +45°C

Limitations



• Not designed for hardrock (primary) gold ore—requires feed precrushing to −150 mm
• Recovery efficiency for fine gold (−75 µm) is limited to 40–55% in sluice configuration; centrifugal concentrators improve this to 70–80%
• Requires minimum 450 m³/hr water supply at 60 m head for optimal operation

Core Features

HighEnergy Rotary Scrubber | Technical Basis: Countercurrent material flow with 12–14 RPM drum rotation creates interparticle attrition | Operational Benefit: Breaks down clay balls and coatings in 2–4 minutes retention time, ensuring complete liberation of gold particles before screening | ROI Impact: Eliminates the need for separate preconditioning drums, reducing capital cost by 15–20% versus twostage systems

Modular Transportable Design | Technical Basis: All components mounted on 3 × 40ft flatrack containers with quickconnect piping and electrical harnesses | Operational Benefit: Plant can be relocated and recommissioned in 5–7 days with a 25ton crane and 4person crew | ROI Impact: Reduces mobilization costs by approximately $180,000–$250,000 per site move compared to stickbuilt plants

AR400 AbrasionResistant Wear Package | Technical Basis: 18 mm AR400 steel in scrubber shell, 12 mm in screen feed box, and 10 mm in all transfer chutes | Operational Benefit: Service life of 12,000–15,000 operating hours before liner replacement, even on quartzrich feed | ROI Impact: Reduces annual wear parts expenditure by 30–40% versus mild steel construction

DualCircuit Recovery Flexibility | Technical Basis: Sluice runs and centrifugal concentrators are installed on independent frames with dedicated feed and discharge points | Operational Benefit: Operators can switch between sluiceonly (high throughput, lower grade feed) and concentratorassisted (lower throughput, higher grade feed) without plant shutdown | ROI Impact: Optimizes recovery efficiency across varying feed grades, improving overall gold capture by 5–8% in heterogeneous deposits

ClosedLoop Water Recirculation | Technical Basis: 1,200 m³/hr settling tank array with cyclone dewatering and 4 × 8/6 F rubberlined slurry pumps | Operational Benefit: Recovers 85–90% of process water, reducing makeup water demand to 120–180 m³/hr | ROI Impact: Lowers water procurement and treatment costs by up to $4,500 per month in waterscarce regions

Hydraulic VariableSpeed Drives | Technical Basis: Independent hydraulic motors on scrubber and screen with electronic speed control (±5% accuracy) | Operational Benefit: Operators adjust drum speed from 8–14 RPM to match feed conditions, optimizing retention time for varying clay content | ROI Impact: Improves washing efficiency by 10–15% on highclay feed, reducing gold loss to oversize rejection

Integrated PLC Control with Remote Monitoring | Technical Basis: Siemens S71200 PLC with HMI touchscreen and optional satellite telemetry | Operational Benefit: Realtime monitoring of feed rate, power draw, bearing temperatures, and recovery circuit performance from a central control room or remote location | ROI Impact: Reduces operator requirements by 1 person per shift and enables predictive maintenance, cutting unplanned downtime by 20–25%

Competitive Advantages

| Performance Metric | Industry Standard (400–500 TPH Class) | 500 TPH Washing Plant Solution | Advantage |
|||||
| Effective throughput on 30% clay feed | 320–380 TPH | 450–500 TPH | 18–32% higher |
| Water consumption per ton processed | 3.5–4.5 m³/ton | 2.4–3.0 m³/ton | 25–33% lower |
| Gold recovery efficiency (−6 mm fraction) | 85–90% (sluice) | 92–96% (sluice + concentrator) | 5–8% higher |
| Screen media changeout time | 8–12 hours | 4–6 hours (quickrelease tensioning) | 40–50% faster |
| Mobilization truckloads | 12–18 loads | 9–11 loads | 25–40% fewer |
| Commissioning time (onsite) | 10–14 days | 5–7 days | 40–50% faster |
| Wear parts cost per ton processed | $0.08–$0.12/ton | $0.05–$0.07/ton | 30–40% lower |
| Availability (operating hours / calendar hours) | 85–90% | 92–95% | 5–8% higher |

Technical Specifications

| Parameter | Specification |
|||
| Nominal Feed Rate | 500 TPH (max 550 TPH on freedigging material) |
| Feed Top Size | 600 mm (with grizzly) |
| Scrubber Dimensions | 2.4 m diameter × 7.5 m length |
| Scrubber Speed | 8–14 RPM (hydraulic variable) |
| Scrubber Drive Power | 2 × 75 kW hydraulic power packs |
| Screen Type | Doubledeck horizontal vibrating screen, 2.4 m × 6.0 m |
| Screen Deck Openings | Top deck: 50 mm; Bottom deck: 6 mm (polyurethane panels) |
| Screen Drive | 2 × 22 kW vibrator motors, 750–900 RPM |
| Recovery Circuit | 12 m sluice run (2 × 6 m modules) OR 6 × 20inch centrifugal concentrators |
| Sluice Width | 1.5 m per module |
| Water Requirement | 450–550 m³/hr at 60 m head |
| Water Recirculation Rate | 1,200 m³/hr (settling tank capacity) |
| Installed Power | 320 kW (excluding feed conveyor and stackers) |
| Generator Requirement | 500 kVA minimum |
| Plant Dimensions (L × W × H) | 38 m × 12 m × 8 m (operating) |
| Transport Dimensions | 3 × 40ft flatrack containers + 2 × 20ft containers |
| Total Transport Weight | 185,000 kg (approx.) |
| Operating Temperature Range | −10°C to +45°C |
| Max Operating Altitude | 4,000 m (derate 3% per 500 m above 3,000 m) |
| Noise Level (at 10 m) | ≤ 85 dB(A) |
| Structural Material | S355JR structural steel, hotdip galvanized |
| Wear Liner Material | AR400 (18 mm scrubber, 12 mm screen feed, 10 mm chutes) |

Application Scenarios

LargeScale Alluvial Mining Operation – West Africa

| Challenge | Solution | Results |
||||
| Deposit contained 25–35% plastic clay that plugged conventional screens every 2–3 hours, reducing effective throughput to 280 TPH. Manual cleaning required 6 workers per shift. | Deployed the 500 TPH washing plant with highenergy scrubber and polyurethane screen panels. Adjusted drum speed to 13 RPM and increased water flow to 500 m³/hr. | Throughput stabilized at 480–510 TPH. Screen plugging reduced to once per 12hour shift. Gold recovery increased from 82% to 93% (confirmed by monthly reconciliations). Payback period: 7 months. |

Contract Mining Operation – Central Asia (High Altitude)

| Challenge | Solution | Results |
||||
| Site at 3,200 m altitude with short 5month operating season. Previous plant required 18 days for relocation between two pits 40 km apart, consuming 25% of the season. | Utilized the modular containerized design. Preassembled all piping and electrical connections at the workshop. Mobilized with 11 truckloads and a 25ton crane. | Relocation completed in 6 days including recommissioning. Operating season extended by 12 days. Additional 6,000 tons processed per season, generating incremental revenue of $240,000. |

River Terrace Deposit – South America

| Challenge | Solution | Results |
||||
| Feed material contained 15% +50 mm oversize with high abrasivity (85% quartz). Standard screen media lasted only 300 hours. Water supply limited to 400 m³/hr from river. | Specified the AR400 wear package and polyurethane screen panels (expected life 2,000+ hours). Activated the closedloop water recirculation system with cyclone dewatering. | Screen media life extended to 1,800 hours. Water makeup demand reduced to 100 m³/hr. Plant availability reached 94% over a 6month operating campaign. Operating cost per ton reduced by 22% versus previous equipment. |

Commercial Considerations

Equipment Pricing Tiers

| Configuration | Description | Indicative Price Range (FOB) |
||||
| Base Package | Scrubber, screen, sluice recovery, conveyors, control system | $1,850,000 – $2,200,000 |
| Enhanced Package | Base + centrifugal concentrators (6 units), cyclone dewatering, enhanced PLC | $2,400,000 – $2,800,000 |
| Turnkey Package | Enhanced + feed hopper with hydraulic grizzly, all stackers, settling tanks, 500 kVA genset, 12month wear parts kit | $3,100,000 – $3,600,000 |

Optional Features

• Remote telemetry package: Satellitebased monitoring with monthly performance reports – $45,000
• Additional sluice modules: Increase recovery area by 50% – $85,000 per module
• Heavyduty feed hopper: 40 m³ capacity with twin hydraulic rams – $120,000
• Dieseldriven hydraulic power packs: For operations without grid power – $95,000
• Coldclimate package: Enclosed operator cabin, heated lubrication systems, lowtemperature hydraulic oil – $65,000

Service Packages

| Package | Scope | Annual Cost |
||||
| Preventive Maintenance | 2 scheduled site visits/year, remote diagnostics, wear parts inspection | $48,000 |
| Full Maintenance | 4 site visits/year, all wear parts supplied, 48hour emergency response | $185,000 |
| Performance Guarantee | Plant availability ≥92%, throughput ≥480 TPH on specified feed, recovery ≥90% | $220,000 (includes penalties/credits) |

Financing Options

• Operating Lease: 36–60 month terms, monthly payments from $52,000 (based on $2.4M equipment value)
• Equipment Loan: 20–30% down payment, 5year term, fixed or floating rates
• ProductionLinked Payment: Monthly payment calculated as percentage of gold recovered (minimum guaranteed payment applies)
• SaleandLeaseback: For operations with existing equipment looking to upgrade

FAQ

1. What is the minimum feed grade required for economic operation of this 500 TPH plant?

Based on current operating cost benchmarks ($3.50–$4.50 per ton processed including depreciation, fuel, labor, and wear parts), a feed grade of 0.15–0.20 g/m³ is the practical economic threshold at current gold prices. At 0.15 g/m³, daily production is approximately 60–75 grams (2–2.4 oz) per 12hour shift. Operations with feed grades below 0.10 g/m³ should consider highercapacity equipment to achieve economies of scale.

2. How does the plant perform on feed with high clay content (above 35%)?

The rotary scrubber is designed for clay content up to 35% at full rated throughput. Above this level, we recommend reducing feed rate to 400–450 TPH and increasing drum speed to 14 RPM. For deposits with clay content exceeding 45%, a preconditioning drum or highpressure water cannons at the feed hopper may be required. Field data from West African operations shows 92% availability maintained on 30–35% clay feed over 6month campaigns.

3. What is the expected gold recovery rate, and how is it verified?

Recovery efficiency depends on feed particle size distribution and gold liberation:

• Sluiceonly configuration: 85–92% for gold coarser than 150 µm
• Sluice + centrifugal concentrators: 92–96% for gold coarser than 75 µm
• Fine gold (−75 µm): 40–55% in sluices, 70–80% with concentrators

Recovery is verified through monthly reconciliation comparing feed grade (from drilling and sampling) against gold production, with adjustments for incircuit inventory. We provide a sampling protocol and calculation methodology with the plant documentation.

4. What are the site preparation requirements before plant delivery?

The plant requires a level area of approximately 60 m × 40 m (including settling ponds). Civil works include:

• Compacted hardstand (300 mm compacted fill or existing competent ground)
• Concrete pads for settling tanks and genset (optional, depending on soil conditions)
• Water supply line (minimum 200 mm diameter) to the plant feed point
• Tailings containment area with sufficient capacity for 4,000–5,000 m³/day of tailings

Site preparation typically takes 5–7 days with a dozer and compactor. The plant itself requires a 25ton crane for assembly.

5. What is the lead time for manufacturing and delivery?

Standard manufacturing lead time is 16–20 weeks from order confirmation, depending on current production schedule. This includes:

• Engineering and documentation: 2 weeks
• Fabrication and assembly: 10–12 weeks
• Factory acceptance testing (FAT): 1 week
• Disassembly and containerization: 1–2 weeks
• Shipping (FOB port): 1–2 weeks to major ports

Expedited delivery (12–14 weeks) is possible with a 10% surcharge, subject to production slot availability.

6. How does the plant handle oversize material (+50 mm)?

Oversize material is rejected by the top screen deck and discharged via a radial stacker to a separate stockpile. This material typically represents 10–20% of feed volume and is either rehandled for further processing (if it contains goldbearing material) or used for road construction and backfill. For deposits where oversize carries significant gold values, an optional secondary scrubber and screen module can be added to process this fraction.

7. What training and ongoing support do you provide for operator teams?

The standard package includes:

• 2week onsite commissioning with 2 senior technicians
• Operator training: 5 days covering plant operation, safety procedures, and routine maintenance
• Maintenance training: 3 days covering wear parts