Mining concentrator synonymous with demanding process conditions
The mining concentrator features various harsh and abrasive processes like crushing, separation, grinding, flotation, thickening, and filtration. Each area requires process equipment to withstand these demanding conditions. Pumps, valves, instrumentation, and piping are often protected with hard coatings or other materials like rubber linings to protect metal components from abrasion. An equipment supplier with an extensive installation base and experience of these concentrator sub-processes can significantly decrease the trial-and-error effect and increase the likelihood of successful installations. Each area’s process conditions may influence mine operators to choose either harder or softer materials. Both can often be successful.
Peristaltic pumps revolutionize thickener underflow pumping in mining operations
Complex mining operations meticulously orchestrate every element for optimal efficiency and safety. Thickener underflow presents challenges. Game-changing advances in peristaltic pump technology have occurred. A rubber-lined centrifugal pump is often utilized for thickener underflow pumping. Such pumps can pass large particles, produce high flow, and handle high solids. Naturally, such pumps need repair, often requiring replacement of the gland seal, suction and discharge volute liners, the casing liner, main bearings, and the rubber-lined impeller. A centrifugal pump repair involves numerous parts, requiring significant repair time. The ideal range for medium density pumped by a rubber-lined centrifugal pump is approximately 35-percent solids. If the thickener requires a higher density slurry of 55–60 percent for delivery to a filtration process, the wear rate inside the centrifugal pump may dramatically increase, significantly increasing operating costs and downtime.
Peristaltic pumps have gained popularity in mining operations for thickener underflow pumping and pumping of medium- to high-density slurries, mainly because the main wear component is a single rubber hose. Peristaltic pumps have no gland seals, so they do not require a constant flow of clean water to the gland seal. The rubber hose on a very large peristaltic pump can be replaced in a few hours, limiting downtime and costs. Peristaltic pumps are also excellent at passing large particles without damaging the rubber hose. They can pump slurries of up to 80-percent solids and experience no significantly increased wear from higher solids pumping. The two most important factors in rubber hoses’ longevity are how often the rubber is compressed, and the temperature to which the rubber is exposed. As the mining industry evolves, innovative technologies like peristaltic pumps will be vital in optimizing efficiency, reducing operating costs, and mitigating environmental impact. By embracing these advances, mining companies can stay ahead of the curve and achieve sustainable growth in a competitive global landscape.
Many different designs of peristaltic pumps affect hose life, MTBF (mean time between failure), and operating costs. Mining operations benefit from understanding and utilizing an eccentric rolling design peristaltic pump that compresses the rubber hose only once every 360-degree revolution. Designs that compress the hose two or more times every 360-degree revolution have a shorter hose lifetime and may severely limit pumping capacity by metal shoes rubbing against the rubber hose and causing heat generation. A single compression rolling eccentric design compressing the hose only once every 360-degree revolution can result in a hose life as much as five times longer than dual compression designs of peristaltic pumps utilizing shoe compression to create the pumping effect. With the eccentric rolling design, a much smaller diameter pump can often be utilized than with the multiple compression shoe design, with a much smaller cost and space footprint.
Pictured above is a single compression eccentric rolling design peristaltic pump. This typically results in more than double the hose life than with multiple compression designed peristaltic pumps. Because the single roller design means there is no heat generation, a lower-cost smaller pump and a smaller footprint can often be utilized than with shoe designs. Compared with multiple compression shoe designs, the hose lifetime in the eccentric rolling design can be up to five times longer, reducing operating expenses incredibly.
To summarize, a peristaltic pump may be a better solution than a centrifugal pump for thickener underflow:
- No gland seal water required
- Very accurate at low and high flows – speed controls pump output, and flow produced is linear with speed output
- Much simpler repair – simply replace rubber hose, and pump can resume service
- Faster repair, limiting downtime
- Lower operating costs
- Positive displacement – peristaltic pump will not lose pumping capacity with increasing head requirements
- Can handle up to 80-percent solids with virtually no increase in rubber hose wear at higher densities.
Delivering higher-density slurries from thickener underflow can have many advantages over the downstream process. Here are some of the benefits that can be achieved:
- By pumping 80-percent versus 35-percent solids, there is a 45-percent reduction in make-up water to be reclaimed and cleaned for future reuse
- Process piping, valves, pumps, instrumentation, and other equipment can be reduced because less volume passes through the process
- Delivering the thickened slurry to a filtration process may enhance the filtration process may be enhanced. The filter may shorten retention time and improve the filter’s daily output, and by delivering a dry feed to the filters, the filter may achieve a drier cake
- Achieving all these benefits means the operating and capital expense can be reduced by as much as 50 percent.
