Air-Operated Double Diaphragm Pumps in Mining

AODD pumps can offer a safe and efficient solution for diverse fluid-handling challenges.

Laura García Nava | SAMOA Industrial

Air-operated double diaphragm (AODD) pumps are widely used in the mining industry due to their versatility and ability to operate reliably in harsh and demanding environments. Mining operations often involve abrasive slurries, corrosive chemicals, high-solid-content fluids and challenging working conditions such as remote locations or explosive atmospheres. In this context, AODD pumps can provide a dependable and flexible solution for fluid handling across multiple stages of the mining process.

One of the main advantages of AODD pumps is their performance capability. They can deliver high flow rates of up to 1,000 liters per minute (l/min) (264 gallons per minute [gal/min]), while also allowing precise regulation of the flow according to process requirements. Flow can be easily adjusted by controlling the air supply, which makes these pumps highly adaptable to changing operating conditions. This flexibility is particularly valuable in mining, where process parameters may vary depending on production rates, ore characteristics or seasonal factors such as groundwater levels.

Another benefit is their solids-handling capability. Diaphragm pumps can transfer fluids containing suspended solids of up to 13 millimeters (mm) (0.6 inches) in diameter without clogging or damaging internal components. AODD pumps do not rely on high rotational speeds, which reduces wear when handling abrasive media. In addition, because they are air-driven and not electrically powered at the pumping mechanism, they do not significantly increase the temperature of the pumped fluid. This is especially important when working with temperature-sensitive chemicals or volatile substances.

Simplicity is also a characteristic of AODD pumps. Their design includes fewer moving parts, which simplifies installation, operation and maintenance. In remote mining sites where technical support may be limited, ease of maintenance becomes a critical factor. Routine service tasks such as diaphragm replacement or valve inspection can be performed quickly, minimizing downtime and reducing operational costs.

Safety and portability further enhance their suitability for mining applications. Being air-operated, these pumps can safely function in hazardous or potentially explosive environments. Explosive Atmospheres (ATEX)-certified models ensure compliance with strict safety regulations in areas where flammable gases or dust may be present. Their compact and modular design allows them to be mounted on carts for mobility or installed on walls and fixed structures depending on site layout. This portability is particularly useful in temporary operations or when pumping points frequently change location within a mine.

Finally, durability is essential in mining, and AODD pumps are able to withstand tough operating conditions. Their construction materials—such as aluminum, stainless steel, polypropylene or polyvinylidene fluoride (PVDF)—provide resistance against corrosion, abrasion and chemical attack.

As a result, they offer long service life even when handling aggressive fluids or operating continuously in heavy-duty applications.

| IMAGE 1: Performance graph used to study the behavior of a pump depending on its working conditions (Images courtesy of SAMOA Industrial)

In Which Mining Processes Are AODD Pumps Used?

Mine-face water evacuation, groundwater extraction from open pits and transfer to central collection ponds
High-pressure filter press feeding to remove solid particles from mine water before recirculation or discharge
General fluid and wastewater evacuation in processing plants
Ore leaching operations, including the transfer and dosing of cyanide or other leaching agents in heap leaching and electrowinning processes
Suction and removal of viscous fluids containing slurry, mud and sludge
Chemical transfer and supply for flotation, pH control and mineral processing
Loading and unloading of tanks, drums and containers
Soil sampling and analysis processes
On-site lubrication services for heavy mining equipment

Which AODD Pump Models Are Recommended?

As in any industry, selecting the appropriate pump model depends on several technical and operational parameters. These include the required flow rate, maximum discharge pressure, chemical compatibility of materials, temperature conditions and the specific characteristics of the fluid being pumped.

A detailed analysis of the end user’s requirements is essential. Factors such as piping layout, suction lift, discharge height, friction losses and fluid viscosity must be considered during the selection process. The pump capacity chart serves as an initial reference point, allowing engineers to compare performance curves and determine the most suitable pump size. However, the final choice must also account for material compatibility and long-term durability under real operating conditions.

In mining applications, 2-inch and 3-inch aluminum pumps are among the most commonly used models. These pumps are particularly suitable for wastewater treatment, sludge handling, slurry transfer and particle removal from process water. Their elastomer diaphragms provide excellent flexibility and resistance, enabling reliable operation with suspended solids and moderately abrasive fluids.

For chemical transfer and dosing processes, 2-inch polypropylene pumps fitted with polytetrafluoroethylene (PTFE) (Teflon) diaphragms are frequently recommended. Polypropylene offers strong resistance to many chemicals, while PTFE diaphragms provide outstanding chemical compatibility and durability. This combination makes them suitable for handling acids, alkalis and treatment chemicals used in mineral processing.

In more aggressive leaching operations involving 98% sulfuric acid, polypropylene may no longer be a fit due to compatibility limitations. In such cases, 1-inch and 2-inch PVDF pumps with PTFE diaphragms are recommended. PVDF offers excellent resistance to highly corrosive chemicals, ensuring safe and reliable performance in acidic environments.

For leaching processes that use 65% nitric acid, stainless steel pumps in 1-inch and 2-inch sizes equipped with PTFE diaphragms are typically selected. Stainless steel provides mechanical strength and chemical resistance suitable for this application, while PTFE ensures diaphragm durability and compatibility.

Ultimately, the correct pump configuration must balance hydraulic performance, material resistance, safety requirements and maintenance considerations. When properly selected and maintained, AODD pumps represent an efficient, safe and long-lasting solution for the diverse fluid-handling challenges found in modern mining operations.

| IMAGE 2: Two-inch plastic pumps with ATEX certification working in mining

Laura García Nava is a mechanical engineer and product specialist at SAMOA Industrial. For more information, visit samoaindustrial.com.

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