1. PAINPOINT DRIVEN OPENING

Are you managing a small to midscale gold operation where consistent, lowcost comminution is critical to profitability? The challenges of processing hard rock gold ore are welldocumented: excessive energy consumption from oversized equipment, high maintenance costs from abrasive materials, and the logistical complexity of operating in remote locations. These factors directly erode your margin. When your primary crushing and grinding circuit is inefficient, you face not only increased power costs but also lost recovery from inadequate liberation. How do you achieve reliable, fine grinding for effective cyanidation or gravity recovery without the capital outlay and operational overhead of a full ball mill circuit? The answer lies in a proven, purposebuilt technology: the modern Custom Stamp Mill.

2. PRODUCT OVERVIEW

A Custom Stamp Mill is a mechanized gravitydriven crushing mill designed specifically for the liberation of freemilling gold from quartz or other host rock. It modernizes the historic stamp battery principle with durable materials and precision engineering for continuous, lowtonnage operation.

Operational Workflow:
1. Feed: Sized ore (typically 2" from a primary jaw crusher) is fed into a enclosed mortar box.
2. Crushing & Grinding: Mechanically lifted heavy stamps (shoes) are dropped in sequence onto the ore within the mortar box, pulverizing it by repeated impact.
3. Discharge & Classification: Pulverized material passes through a screen at the mortar box discharge, with oversize material recycled and fines reporting to subsequent gold recovery processes (e.g., sluices, concentrators).

Application Scope & Limitations:
Ideal For: Freemilling gold ores, pilot plants, smallscale commercial operations (150 TPD), historical mine reprocessing, and locations with limited water or power infrastructure.
Limitations: Not suitable for refractory ores requiring fine grinding below 100 mesh for liberation, or for hightonnage operations exceeding 75 TPD. Performance is optimal on brittle, siliceous ores.

3. CORE FEATURES

Modular Frame Design | Technical Basis: Bolttogether highcarbon steel structure | Operational Benefit: Enables transport to remote sites in standard containers and rapid onsite assembly with minimal heavy lifting | ROI Impact: Reduces installation time by up to 60%, lowering total project mobilization costs

Interchangeable Stamp Shoes & Dies | Technical Basis: Cast manganese steel or alloy chrome iron wear surfaces | Operational Benefit: Operators can reverse or replace highwear components without dismantling the stamp assembly, extending service intervals | ROI Impact: Cuts planned maintenance downtime by approximately 30% and standardizes spare parts inventory

Adjustable Drop Height & Cadence | Technical Basis: Variablefrequency drive (VFD) on camshaft motor | Operational Benefit: Provides precise control over impact energy and grind size to match ore hardness variability; allows softstart capability | ROI Impact: Optimizes specific energy consumption (kWh/ton) and improves overall gold recovery consistency by ensuring target liberation size

Integrated Water Injection System | Technical Basis: Controlled manifold with solenoid valves at each mortar box | Operational Benefit: Suppresses dust at point of impact and creates a slurry for efficient discharge; flow is adjustable per stamp | ROI Impact: Mitigates health/safety risks and environmental dust emissions while improving material handling

Centralized Grease Lubrication | Technical Basis: Automated system servicing all major bearings on camshaft and lifters | Operational Benefit: Ensures critical moving parts operate under consistent lubrication pressure in dusty environments | ROI Impact: Prevents premature bearing failure, a leading cause of unplanned downtime in abrasive applications

HeavyDuty Screen Cartridge System | Technical Basis: Quickrelease clamp mechanism on mortar box discharge | Operational Benefit: Allows screen mesh changes in under 15 minutes to adjust final product size for downstream process optimization | ROI Impact: Increases plant operational flexibility and throughput by minimizing process changeover delays

4. COMPETITIVE ADVANTAGES

| Performance Metric | Industry Standard (Small Ball Mill / Hammer Mill) | Custom Stamp Mill Solution | Advantage (% improvement) |
| : | : | : | : |
| Specific Energy Consumption (kWh/ton) | 12 18 kWh/ton (for similar grind size) | 8 10 kWh/ton (gravitydriven impact) | ~35% Reduction |
| Wear Part Cost per Ton Processed| $1.50 $3.00 (hammers/liners) | $0.75 $1.25 (stamp shoes/dies)| ~50% Reduction |
| OnSite Installation Time| 46 weeks (foundation, alignment) | 12 weeks (modular assembly) | ~70% Reduction |
| Target Grind Size (P80)| Variable; can be less efficient at coarser grinds| Optimal range of 20100 mesh for freemilling gold| More efficient within designed range|
| Noise Level at 10m| 95105 dB(A) (constant noise) | 8590 dB(A) (intermittent impact)| ~50% Lower Avg. Sound Pressure|

P80 = The sieve size that passes 80% of the product.

5. TECHNICAL SPECIFICATIONS

Capacity Range: Configurable from 1 to 75 Tons Per Day (TPD), based on number of stamps (310 units common).
Power Requirements: Primary drive motor(s): 1575 kW total (20100 HP), dependent on stamp weight and count. Standard supply: 400/480V, 3phase, 50/60 Hz.
Material Specifications: Frame: ASTM A36 Carbon Steel; Stamps & Shoes: HighChrome Cast Iron or Manganese Steel; Mortar Box Liners: AbrasionResistant Steel Plate (>400 BHN).
Physical Dimensions: Single stamp unit footprint: ~1m x 1m; A typical 5stamp mill with feed conveyor occupies approx. L6m x W3m x H4m.
Environmental Operating Range: Ambient Temperature: 20°C to +45°C; Humidity Tolerance: Up to 95% noncondensing; Designed for operation at altitudes up to 3,000m.

6. APPLICATION SCENARIOS

SmallScale Hard Rock Mine, West Africa

Challenge:A remote site with limited grid power required a simpletooperate grinding circuit for vein quartz ore to replace manual crushing. Diesel generation costs made highenergy milling prohibitive.
Solution:A customdesigned fivestamp mill powered by a single diesel generator was installed alongside shaking tables.
Results:The operation achieved a stable throughput of 8 TPD at a grind of 30 mesh. Gold recovery improved to >92%, while fuel consumption dropped by over half compared to the previously considered small ball mill option.

Historic Tailings Reprocessing Project

Challenge:A contractor needed to reprocess old mill tailings containing coarse liberated gold locked in silicate fragments using a mobile plant with quick setup.
Solution:A skidmounted threestamp mill was integrated into a containerized gravity recovery plant.
Results:The plant was operational within five days of arrival on site.The stamp mill effectively broke apart the silicate conglomerates without overgrinding malleable gold particles.Gravity recovery rates exceeded initial estimates by over fifteen percent due to improved liberation characteristics.

7.COMMERCIAL CONSIDERATIONS

Pricing Tiers:
Base Unit(3Stamp):Includes frame,cams,motor,VFD,and one set of wear parts.
PlantReady Package(5Stamp):Includes base unit plus integrated feed conveyor,sump,and slurry pump,motor control center(MCC).
SkidMounted/Turnkey Module:Fully assembled unit tested prior to shipment including all ancillary equipment.

Optional Features:Dust enclosure kit,screen cartridge sets(assorted meshes),advanced vibration monitoring sensors,wash water recycling system.

Service Packages:Standard warranty covers structural integrity.Available extended service agreements include annual inspections,wear part discounts,and priority technical support.Financing options include equipment leasing through partner institutions tailored towards mining projects.

8.FAQ

Q:What primary crusher feed size is required for an efficient stamp mill operation?
A.For optimal performance,the feed should be reducedto minus two inches(50mm).This is typically achievedwitha small jaw crusher.A correctly sized feed prevents jammingand ensures consistentstamp drop energyis appliedto particle breakage rather than oversized rocks.

Q:Cana stamp mill handle wet or clayrich ore?
A.Stamp mills perform beston dryor moderately moist,friable ore.High clay contentcan leadto packingin themortar box reducing efficiency.In such cases,a scrubbingor classification step priorto crushingis recommended.Field data showsaddinga simple trommel screen aheadof themill can resolve this issue.

Q:Whatisthe expectedlifespanof keywear components?
A Under normal operation processing quartz ore manganese steel shoes require rotation after approximately500 hoursand replacementafter1500to2000 hoursof operation.Mortarbox dies last significantly longer.This will varybasedon specificore abrasiveness which we can evaluatefrom asample.

Q How does thenoise compareto other milling options?
A Whilethe impactcreates sound itis intermittentand often perceivedas less disruptive than constant highfrequency noisefrom hammer mills Proper installationwith basic acoustic enclosuresreadily achievescompliancewith mostsite regulations

Q Are spare parts readily available?
A Yes All wearing parts are standardizedand stockedfor immediate dispatch Critical structural componentsare fabricatedfrom common industrial steel profiles minimizing supplychain risk evenfor remote locations