In terms of pumping mud, few applications are more challenging than the hydraulic transportation of heavy-duty mud in oil sands production. * Not only do pumps have to deal with the highly corrosive nature of the fluid being pumped, they are also expected to operate in some of the harshest environments in the world.

In January 2020, GIW Industries commissioned its largest ever heavy-duty centrifugal slurry pump to operate in the Canadian oil sands, namely TBC (Tie Rod Structure)-92. Named after its 92-inch (2,337 mm) impeller, TBC-92 is the largest and heaviest slurry pump in the oil sands industry and the latest product in the powerful high-pressure pump series provided by GIW (Figure 1).

In mining, dredging, and oil sands production, the biggest challenge is to accommodate high-density mud and highly abrasive gravel. It is crucial that the mud is passed through the pump to minimize the wear on the pump casing, impeller, shaft and sealing mechanism. In addition, they must be able to provide high flow rates and withstand harsh operating environments.

Alberta, Canada has the world's third largest oil reserves, these reserves exist in the form of oil sands.

Extracting and processing oil from sand and bedrock is a challenging process that involves removing bituminous ore and transporting it to a crushing plant. The crushed ore is then mixed with warm water to form a dense slurry, which is then transported to the extraction site through a pipeline, where the asphalt is separated from the sand and rock. After extraction, the remaining solids (or tailings) are usually transported to the sedimentation tank by different pumps.

These processes require extensive use of mud and water transfer pumps that can handle large amounts of liquids at high pressures and temperatures.

Relying on its years of mining slurry pump design experience, GIW has custom-designed slurry pumps that combine advanced materials, hydraulics and patented mechanical designs, the latest of which is TBC-92.

"Our customer needs a higher capacity pump that can output 10,000-11,000 cubic meters per hour at a development head of nearly 40 m and a maximum working pressure of 4,000 kPa," Mollie Timmerman, GIW business development manager, reports. “The pump also needs to be able to pass through rocks with a diameter of approximately 130 mm (total channel size is required to be 10 inches or 254 mm) and handle mud with a density of more than 1.5 SG (specific gravity). In addition, the customer’s target maintenance interval (the interval between planned maintenance Running time) is approximately 3,000 hours. They expressed interest in maximizing maintenance intervals, and based on initial signs of wear, they currently hope to achieve approximately 6,000 hours (that is, six to eight months) between pump overhauls."

The first batch of GIW's TBC-92 pumps were directly used in Alberta as hydraulic transportation services to transport bituminous ore from the crusher to the extraction plant. The pumped liquid is a mixture of water, asphalt, sand and large rocks. The screens are in place to keep these rocks within a manageable size range, but the top size can still reach a diameter of 130 mm (or larger). The abrasiveness of the mud is what distinguishes the mud pump from other pumps used in the industry. Wear and erosion are facts in life. GIW has decades of experience in slurry pump design and material development, which can help extend the life of these key components to match the plant's planned maintenance cycle.

"GIW already has a pump that can meet the output requirements. This is the MDX-750, which has been popular in rolling mill operations in Central and South America for nearly 10 years," Timmerman explained. "However, the customer's application requires a pump with higher pressure capacity and larger rock capacity, so we developed TBC-92 as a response, which provides the best solution for maximizing production."

The structural style of GIW's TBC pump series is fixed with large ribbed plates and tension bolts, which can be used for very high pressure service and maximum wear resistance. Originally developed for dredging services and then introduced into oil sands in the 1990s, the TBC pump series has evolved into a fully developed pump series serving tailings and hydraulic transportation applications in the oil sands, phosphate, dredging and hard rock mining industries . These pumps are usually combined in a booster station to build up pressures up to 750 psi (5,171 kPa) to account for the pipe losses encountered over such a long distance. The robust structure of the TBC pump is ideal for this job, while ensuring maximum availability of the equipment under severe wear and tear.

Able to provide pressures up to 37 bar and flow rates of over 18,200 cubic meters per hour and temperatures up to 120⁰C, the TBC series is a horizontal end-suction centrifugal pump with maximum wear resistance. The tension bolt design of the pump is easy to maintain and transfer the stress load from the wear-resistant white iron shell to the non-bearing side plate without the need for heavy and heavy double-wall structure. TBC-92 combines the best elements of earlier TBC models, including the groundbreaking TBC-84 oil sands tailings pump, also known as the "super pump". The pump also incorporates the features of GIW's cutting-edge MDX product line, which is used in heavy-duty mining circuits in the hard rock mining industry around the world.

The total weight of the TBC-92 is approximately 209,000 pounds (95,000 kg)-roughly equivalent to a fully loaded Airbus A321 aircraft. The housing alone weighs 34,000 pounds (15,500 kg). The main features of the pump include a mud divider, which significantly extends the life of the suction liner by reducing particle recirculation between the impeller and the liner. The large diameter impeller allows the pump to run at a slower speed, thereby increasing wear life. The lower speed also allows the pump to operate in a wider flow range to adapt to fluctuating flow conditions (Figure 2A). In order to make maintenance easier, the pump is equipped with a special two-piece suction cup design, which helps reduce tooling time and provide safer lifting. The customer received a lifting device dedicated to the pump to facilitate the safe removal and installation of worn parts. The pump also has a durable suction bushing that can be adjusted without shutting down the pump.

The commissioning of TBC-92 marks an important milestone for GIW, and the company is now equipped with pumps for hydraulic transportation applications in all operating Canadian oil sands plants. TBC-92 is designed to handle heavy mud transportation while reducing the total cost of ownership. Minimal labor and maintenance time helps maximize production and profit.

"This new pump combines years of experience and lessons learned in oil sands operations and uses our latest hydraulic and wear technology," Timmerman said. "Because this is the heaviest TBC pump we have ever designed, special attention has been paid to maintainability, as well as the material selection and construction of pressure-bearing parts."

Given that GIW has been developing pumping technology and wear-resistant materials in the global mining industry since the 1940s, it is not surprising that GIW has become an important force in pumping solutions for the oil sands industry.

These pumps have a considerable impact on the way the excavated sand, rock and asphalt are transported to the upgrading plant. By adding water to the excavated material, the slurry can be pumped to the quality upgrader along the pipeline efficiently. Pipe agitation helps to separate the asphalt from the sand during transportation. There is also an added benefit of eliminating the need for trucks. GIW estimates that the cost of transporting oil sands in this way can reduce the cost of 2 US dollars per barrel, and it is more environmentally friendly. These pumps also play an important role in transporting coarse tailings to the tailing pond. GIW provides pumps for the extraction process and other production areas (HVF, MDX, LSA, etc.).

Understanding the properties of slurries and how they behave when pumped is the basis for the development of these products. For many years, GIW has been obtaining mud samples from customers to test the hydraulic pressure and materials of pumps and pipelines (Figure 3). The R&D facilities include multiple mud test benches on campus and a hydraulic laboratory dedicated to pump performance testing.

These activities are at the core of the company's pump development plan. If the company encounters a problem, GIW R&D staff can view the problem and provide suggestions for remedial measures. Experience does show that in many cases, the problem is not the pump, but the interaction between the pipe and the pump.

Customer feedback on the application helps to develop new tools and pump designs. By bringing together customers and scholars from all over the world, sharing their experience and research with internal experts, a large amount of investment in R&D and manufacturing has promoted the design of all GIW pump products, materials and wear parts.

GIW Chief Product Manager Leo Perry said: “The mining and dredging industries clearly tend to use larger pumps, and oil sands are no exception.” “The first TBC pump in the oil sands was the TBC-46 (impeller diameter 46). Customers are designing their facilities for higher and higher production volumes and demand the same equipment that keeps their production running. Although these larger pumps require more power, they also allow for higher levels with less maintenance downtime In general, the efficiency is improved compared to the same output of a large number of smaller pumps."

Finally, he said: “Bigger pumps go hand in hand with larger facilities, larger pipelines, and increased production, all of which continue to increase year by year. Other customers and industries are also showing interest in this size, in the near future It’s not surprising to see more of these pumps used in similar applications."

*This story was written and submitted by GIW, with only a few edits

International Mining Team Publishing Ltd 2 Claridge Court, Lower Kings Road Berkhamsted, Hertfordshire England HP4 2AF, UK

Phone: 44 (0) 1442 870 829 Fax: 44 (0) 1442 870 617 Email: [email protected] or [email protected]