Subject: Maximizing Yield & Minimizing Downtime in HighVolume Sand & Gravel Operations

1. PAINPOINT DRIVEN OPENING

Every ton of sand and gravel you process carries a hidden cost. Are your current screening and washing systems struggling with inconsistent feed material, leading to 1520% fines loss in your washed sand? Is your plant experiencing 46 hours of unplanned downtime per week due to clogged screens or worn impeller blades in your sand washing equipment? For plant managers and engineering contractors, the operational challenges are clear: rising energy costs (often $0.08$0.12 per ton processed), strict environmental regulations on silt content (typically <3% for concrete sand), and the constant battle against equipment abrasion that reduces component life by 3040% in highsilica deposits.

Your current setup likely faces three specific bottlenecks: inefficient fines recovery (losing saleable product to settling ponds), high water consumption (exceeding 1,500 gallons per ton of sand produced), and frequent mechanical failures in the dewatering phase. How can you increase your spec sand output by 15% while cutting water usage by 25%? The answer lies in a system designed for the specific abrasion and classification demands of China’s aggregate deposits.

2. PRODUCT OVERVIEW

The HighEfficiency Sand Washing & Fines Recovery System (Model: SWR3000) is a modular, closedloop processing unit engineered specifically for sand and gravel mining operations processing 150300 tons per hour. This system integrates three core functions: scrubbing, classification, and dewatering into a single, compact footprint.

Operational Workflow:
1. Feed & Scrubbing: Runofmine sand (010mm) enters a dualshaft spiral classifier. Hightorque paddles break down clay balls and organic matter, achieving a 95% liberation rate of sand particles.
2. HydroCyclonic Classification: Slurry (2025% solids) is pumped into a cluster of polyurethane hydrocyclones. This stage separates saleable sand (75600 micron) from ultrafine silt (<75 micron) with a cutpoint accuracy of ±5 microns.
3. Dewatering & Stockpiling: The classified sand slurry flows onto a highfrequency dewatering screen (0.5mm aperture). The screen produces a dripfree sand product with a surface moisture content of 1215%, ready for immediate stockpiling or loading.

Application Scope: Ideal for river sand, crushed sand (manufactured sand), and natural gravel wash plants. Limitations: Not designed for materials with >8% clay content without prescreening; requires a consistent feed rate of ±10% to maintain hydrocyclone efficiency.

3. CORE FEATURES

AbrasionResistant Polyurethane Components | Technical Basis: Highdensity polyurethane (Shore A 90) vs. standard rubber | Operational Benefit: Reduces wear part replacement frequency by 60% in highsilica sand (Mohs hardness 7) | ROI Impact: Saves $12,000$18,000 annually in spare parts and labor for a 200 TPH plant.

Variable Frequency Drive (VFD) on Main Pump | Technical Basis: 160kW motor with VFD controlling pump speed (8001450 RPM) | Operational Benefit: Allows operators to adjust cutpoint and recovery rate onthefly to match feed variations | ROI Impact: Reduces energy consumption by 1822% compared to fixedspeed pumps, saving $0.015 per ton.

Integrated Silt Thickening Cone | Technical Basis: Gravity settling with a 45degree cone angle and underflow density control | Operational Benefit: Captures 90% of process water for immediate reuse, reducing fresh water intake | ROI Impact: Cuts water consumption from 1,500 gal/ton to 400 gal/ton, lowering pumping and treatment costs.

QuickRelease Screen Panels | Technical Basis: Tensioned polyurethane panels with wedgelock system | Operational Benefit: Screen deck changeout time reduced from 4 hours to 45 minutes | ROI Impact: Increases plant availability by 34% per year, translating to 1,500 additional tons of production.

DualFeed Inlet Design | Technical Basis: Two independent feed points with adjustable flow dividers | Operational Benefit: Ensures even distribution across the hydrocyclone cluster, preventing roping and blockages | ROI Impact: Eliminates 90% of cyclone blockages, reducing maintenance downtime.

Automatic Lubrication System | Technical Basis: Centralized grease pump with programmable intervals for all bearings and seals | Operational Benefit: Eliminates manual greasing errors and extends bearing life by 40% | ROI Impact: Prevents catastrophic bearing failures, saving $5,000 per repair event.

CorrosionResistant Steel Frame | Technical Basis: Hotdip galvanized steel (85micron coating) on all structural members | Operational Benefit: Withstands constant exposure to water and abrasive slurry without rust | ROI Impact: Extends equipment lifespan by 1015 years in coastal or highhumidity environments.

4. COMPETITIVE ADVANTAGES

| Performance Metric | Industry Standard (Spiral Washer) | SWR3000 Solution | Advantage (% Improvement) |
| : | : | : | : |
| Fines Recovery Rate | 7580% (lost to pond) | 9295% (recovered) | +1520% |
| Product Moisture Content | 1822% | 1215% | 33% |
| Water Consumption | 1,2001,800 gal/ton | 350450 gal/ton | 70% |
| Wear Part Life (Silica Sand) | 400600 hours | 1,2001,500 hours | +150% |
| Energy per Ton Produced | 1.82.2 kWh/ton | 1.21.5 kWh/ton | 30% |
| Changeover Time (Screen) | 4 hours | 45 minutes | 81% |

5. TECHNICAL SPECIFICATIONS

• Model: SWR3000
• Capacity: 200300 TPH (dry sand basis)
• Feed Size: 010 mm (max 15 mm)
• Power Requirements: 185 kW total (160 kW main pump + 25 kW screens & conveyors) @ 380V/50Hz/3Phase
• Material Specifications: Polyurethane (cyclones & screens), AR400 steel (spiral shafts), 316L stainless steel (water piping)
• Physical Dimensions: 18m (L) x 4.5m (W) x 6.5m (H) – modular skid design
• Weight: 28,000 kg (operational)
• Environmental Operating Range: 0°C to 45°C ambient; slurry temperature up to 60°C
• Water Requirement: 350450 m³/hour at 34 bar inlet pressure

6. APPLICATION SCENARIOS

LargeScale River Sand Operation (Sichuan Province) | Challenge: A 500 TPH plant was losing 40 TPH of fine sand (<150 micron) to settling ponds due to inefficient spiral classifiers. Water usage was 1,600 gal/ton, exceeding local extraction permits. | Solution: Installed two SWR3000 units in parallel to process the 05mm fraction from the primary screen. | Results: Fines recovery increased to 94%, adding 35 TPH of saleable concrete sand. Water consumption dropped to 420 gal/ton. The client achieved a 14month ROI on the equipment cost.

Manufactured Sand (Crushed Granite) Plant (Guangdong Province) | Challenge: The VSI crusher produced sand with high fines content (18% passing 75 micron), making it unsuitable for C30 concrete. Dewatering screens clogged every 2 hours. | Solution: The SWR3000 was configured with a 100micron hydrocyclone apex to remove excess fines. | Results: Fines content in final product reduced to 5%. Screen blinding eliminated. The plant now produces 220 TPH of speccompliant manufactured sand, commanding a $2.50/ton premium.

Gravel Wash Plant Upgrade (Hebei Province) | Challenge: Existing bucket wheel washers consumed 2,000 gal/ton and produced sand with 22% moisture, causing stockpile slumping and truck loading issues. | Solution: Replaced bucket wheel with SWR3000 system. | Results: Moisture content reduced to 13%. Stockpile stability improved. Water recycling allowed the plant to operate on a closedloop system, eliminating discharge fees.

7. COMMERCIAL CONSIDERATIONS

Equipment Pricing Tiers (FOB Shanghai Port):

• Standard Package (SWR3000S): $185,000 $210,000. Includes base unit, standard polyurethane wear parts, and manual lubrication.
• Premium Package (SWR3000P): $245,000 $275,000. Includes VFD on main pump, automatic lubrication system, and 2year supply of wear parts.
• Turnkey Package (SWR3000TK): $320,000 $360,000. Includes all above, plus feed conveyor, product conveyor, control panel with PLC, and onsite commissioning (5 days).

Optional Features:

• Remote monitoring system (SCADAready): +$12,000
• Additional hydrocyclone cluster for higher capacity: +$18,000
• Slurry density gauge for automated cutpoint control: +$8,500

Service Packages:

• Basic Warranty: 12 months on mechanical components, 6 months on wear parts.
• Extended Service Contract: $15,000/year includes 2 site inspections, priority technical support, and 10% discount on spare parts.
• Performance Guarantee: Optional addon guaranteeing 90% fines recovery or contract penalty.

Financing Options:

• 30% down payment, 70% balance upon delivery.
• Leasing options available (3660 months) through partner financial institutions.
• Volume discounts for orders of 3+ units (5% discount).

8. FAQ

Q: Can the SWR3000 handle feed material with high clay content (58%)?
A: Yes, but we recommend a prescreening step (2mm aperture) to remove large clay balls. The dualshaft spiral scrubber is effective at breaking down clay coatings, but excessive clay (>8%) can overload the hydrocyclone underflow.

Q: What is the typical payback period for this system?
A: Based on field data from 12 installations, the average payback period is 1418 months. This is driven by water savings ($0.03/ton), increased fines recovery (adding $0.50$1.00/ton in revenue), and reduced maintenance costs.

Q: How does the system perform with manufactured sand from a VSI crusher?
A: It is highly effective. The hydrocyclone cluster can be tuned to remove excess fines (typically 1520% in VSI sand) down to 35%. This is a common application for clients upgrading their MSand quality.

Q: What is the lead time for delivery?
A: Standard lead time is 810 weeks from order confirmation. Turnkey packages require 1214 weeks due to integration and testing. Expedited delivery (6 weeks) is available for an additional 10% fee.

Q: Can the system be integrated with an existing plant control system?
A: Yes. The standard PLC uses Modbus RTU protocol. We can integrate with AllenBradley, Siemens, or Schneider systems. The SCADAready option provides OPCUA connectivity.

Q: What is the warranty on the polyurethane wear parts?
A: Polyurethane cyclones and screen panels carry a 6month warranty against manufacturing defects. Expected service life in typical sand (23% silica) is 1824 months. In highsilica sand (>5%), expect 1218 months.

Q: Do you provide onsite training for operators?
A: Yes. The Turnkey package includes 2 days of onsite training covering operation, maintenance, and troubleshooting. Additional training days are available at $1,500/day plus travel expenses.