In the early days of mining, operations were basic—identify where the commodity might be buried, dig a hole and send people in to retrieve it. For generations, this was the norm even though this process had drawbacks—most notably, the dangers that miners faced every second that they were underground.
Today’s mining operations barely resemble those of the past, with sophisticated equipment and systems making the identification of lodes (deposits of metalliferous ore that fill or are embedded in a fissure in a rock formation) more precise and the retrieval of the commodity more effective. Perhaps the most important advance in mining operations is the increased determination to make the operation as safe as possible for the miner, the communities in which the mines operate and the environment.
The dedication to improved safety has paid off. For example, in early 2013, the Mine Safety and Health Administration (MSHA) reported that the fatality rate in U.S. mines was at its lowest ever in 2012, based on the number of man-hours that were worked during the year. Additionally, the MSHA reported that work-related fatalities in mines totaled 36 in 2012, which was one more than the lowest-ever total of 35 in 2009.
Mining safety is most precarious in underground mines. Advances in the methods used to dig mines and to shore up shafts have helped mitigate much of the potential for cave-ins, collapses and explosions. Ensuring the safety of the mine infrastructure is just one part of the equation, however. Within those mines, many different types of equipment are required during the exploration and extraction processes. One of the most common is industrial pumps, which are used for many applications within a mining operation.
Some air-operated double-diaphragm (AODD) pumps feature the operational reliability that is paramount to the success of a mining operation. They also operate safely to help prevent mining accidents.
As mining operations and systems have increased their level of sophistication, some AODD pumps have played a huge role in enhancing their performance and overall safety.The Challenge
Pumps are pushed to their limits in mining operations. Nearly all mining processes occur in extremely harsh conditions, and the pumps are tasked with handling a wide range of solids, abrasives and particulate-ridden liquids. AODD pumps are often selected for these unforgiving tasks because their design enables them to outperform other pump styles.
However, not all AODD pumps are created equal. Excessive downtime can limit a mining operation. Production delays can have an adverse effect on the mine’s cost-effectiveness. For this reason, the AODD pump technology must reliably meet the needs of demanding mining operations.
Too often, manufacturers of AODD pumps do not take the time to create a pump that can stand up to the rigors of the mining site. This can result in a pump that will potentially fail catastrophically when used in an unsuitable application.
This delays production and puts mine-site personnel at risk of injury or death. Pumps that are less durable are also likely to require more basic maintenance, which will result in increased downtime and added ancillary costs for the mining company.
Some AODD pump models may struggle to deliver the discharge pressures and flow rates that are required for severe-duty pumping. This weakness can hamper production rates and increase the risk of pump breakdowns and the potential for a catastrophic failure that can lead to increased safety risks.
The Solution
One type of AODD pump technology has proven successful when used in severe-duty mining applications. Mine operators use these pumps in many applications, including:
- Froth flotation for particulate separation in slurries
- Leaching of commodity byproducts
- Transfer and treatment of mine tailings
- Wash bays for large-scale machinery and vehicles
- Above- and below-ground dewatering
- Bulk liquid-chemical transfer
- Raw material transfer
- Water recirculation
- Water/land reclamation
- Explosive atmospheres
- Oil separation processes
- Onsite bulk-fuel transfer
- Soap dispensing through onsite bath houses
A specific, clamped metal AODD pump incorporates many design enhancements that make it a first choice for many mine operators. Chief among these are a shock-absorbing polyurethane screen base that absorbs the impact from solid particles and increased internal clearances to prevent aggregate entrapment, resulting in maximized durability. These pumps also feature an integrated suction strainer with the option of plumbed suction, if needed.
A new air distribution system (ADS) allows the user to control flow rates and air consumption with the turn of a dial. They are available in three sizes: 38 millimeters (1½ inches), 51 millimeters (2 inches) and 76 millimeters (3 inches). All are available in either aluminum or ductile-iron construction materials, are submersible, intrinsically safe and lube-free. They can run dry, have anti-freezing properties and can handle pressures up to 125 psi. Depending on the model, flow rates range from 305 to 776 liters per minute (81 to 205 gallons per minute).
These pumps operate in the safest manner possible for site personnel and the environment. They are manufactured to Quality Management System (ISO 9001), Environmental Management System (ISO 14001) and Occupational Health and Safety Advisory Services (OHSAS 18001) standards.
Conclusion
The operating conditions at most mines are trying at best. Harsh operating environments and the ever-present threat of accidents make attention to detail a front-of-mind, daily concern. Some AODD pump technology can help make mining conditions safer for site personnel and the environment. These pumps allow mining companies to meet their production goals and do it in the safest, most employee-friendly way possible.
Air Distribution System Improvement
The air distribution system (ADS) of AODD pumps is critical to the pump’s operation. A new ADS on some AODD pumps represents an improvement in the level of an AODD pump’s energy efficiency, which is critical as industrial plants work to reduce air consumption, energy usage and their carbon footprints.
While the operation of an AODD pump has basically remained constant during the past 60 years, improvements have been made in the pump’s ADS that address its rate of air consumption in relation to the product flow rate and how much air can be wasted during the pumping cycle, with that wasted air resulting in an added cost for the plant operator. The gremlin in traditional ADS has been the “overfilling” of the air chamber at the end of each pump stroke without any corresponding displacement of fluid.
To combat pump overfilling, the new ADS restricts the air flow into the air chamber near the end of each pump stroke so that only enough air is introduced to maintain the pumping process. This is accomplished through the incorporation of an air control spool that automatically meters the air to prevent overfilling with no reduction in product yield. The result is reduced air consumption while maximum operational efficiency and flow rates are maintained.
The ADS design features fewer operating parts, resulting in less downtime and simplified maintenance. It is available with a single-point exhaust option (for submersible applications) and offers plug-and-play operation. It also reduces the AODD pump’s air consumption by up to 60 percent. These savings in air consumption will lower the operating cost for compressor life-cycle costs and operating fuel.
