GIW Industries Inc. is celebrating a huge success with the recent replacement of a mill discharge pump at an iron ore plant in northern Minnesota. The new MDX 42 wet end achieved a remarkable 24,000 hours between rebuilds — fitting seamlessly into the customer's routine maintenance schedule and doubling the wear life of the competitor's pump.

Long-time customer, new technology

This feat wasn't GIW's first interaction with this long-standing customer. The iron ore plant was built using GIW® Minerals LSA pumps in the mid-1970s, and many of these pumps are still in operation.

Due to the abrasive materials these discharge pumps process, they must be periodically rebuilt. For this particular customer, the optimum mill maintenance schedule is every 8,000 hours, so it's imperative that their rebuild cycle coordinates with these routine shutdowns.

Over the years, the customer tried several different components to increase the average operating time; they even recently turned to a competitor, who was ultimately able to achieve some additional uptime between rebuilds. While this nominal increase in uptime was appealing, it didn't match the plant's 8,000-hour maintenance cycle. Thus, the competitor's solution was rendered worthless.

During this same period of time, GIW applied its adjustable slurry diverter technology to the cyclone feed services in another area of the plant. This replaced the original LSA-14x16-36 with the MDX-12x14-36 in Gasite® 18G material. This switch greatly increased the average time between rebuilds from 4,000 to 8,000 hours, which corresponded perfectly with the plant's normal outage interval.

Realizing this material and timing could be a better fit for their process, the customer approached GIW to see if the same technology could be applied to their mill discharge pumps.

Uptime is everything

"The most important benefit in mineral processing is to maximize production time and minimize maintenance," says GIW Industries Inc. Region Manager Ben Altman. "Longer runs offer a big financial benefit to the customer — uptime is everything!"

In order to achieve maximum uptime for the customer, GIW set its sights on extending the time between rebuilds for the customer's mill discharge pumps.

GIW worked closely with the customer's engineering department to trend the mill output, and submitted a proposal for testing the new pump. The MDX 42 with adjustable slurry diverter technology was selected for the job. To increase the wear life even further, GIW added a Gasite® 32G high chromium white iron alloy suction liner. The mill also took this opportunity to install a variable frequency drive (VFD) to optimize the pump operating speed feeding the roughers, or magnetic separators.

24,000 hours — and counting

The results were beyond satisfactory, with the MDX wet end achieving 24,000 hours between rebuilds. To make the MDX's performance even more impressive, during the rebuild, the maintenance team discovered that there was still a serviceable thickness remaining. This indicates that many of the parts could have run even longer.