Case Histories

GIW All-Metal Pumps Applied in Tailings and Hydrotransport

GIW's on-going efforts to help its customers develop more efficient, economical and energy-savings applications have once again paid off.

In fact, they've hit pay dirt this time.

That's because Syncrude Canada Ltd., the world's largest producer of crude oil from oil sands, is using a new technology called hydrotransport, which they have been developing since the early 1980's, to mine Canada's oil sands deposits. These deposits, located in the sub-Arctic regions of northern Alberta, represent about a third of the world's known useful petroleum and are expected to yield more than 300 billion barrels of oil-rich bitumen.

However, extracting the bituminous resource has historically been difficult and expensive because the oil is bonded to sand by water and is often kilometers away from processing plants.

Turn-of-the-century attempts to mine oil sands were so cumbersome and expensive that they were discontinued. Then, in the 1920's, the hot water extraction process was developed. Extensive research over the next 40 years made the process commercially viable.

In this process, the sand is conveyed by belt to the plant, where it is mixed with hot water and steam and heated to a slurry temperature of 180° Fahrenheit (82° Celsius). The oil sands are then processed in large tumblers, which liberate the oil from the sand. The bitumen rises to the top of the settling vessels, leaving a middle layer of water and a lower layer of sand tailings, which are pumped to a settling basin. The process is costly, however, due to construction and maintenance of the conveyor belts and other equipment. Therefore, the farther the mines are from the processing plant, the more cost-effective hydrotransport becomes.

GIW Originally Studied Syncrude's Tailing Operations
GIW's involvement with Syncrude began not with hydrotransport but with their tailings operations. When Syncrude's design engineers began considering all-metal pumps instead of the rubber-lined pumps they had been using in their tailings operations, they asked several pump manufacturers to bid on supplying the pumps.

As the successful bidder, GIW agreed to test their metal pumps for this application. To do so, GIW transported two truckloads of tailings sand from Syncrude's mine to its Hydraulic Testing Laboratory in Grovetown, Ga., the world's largest and most sophisticated slurry test labs. It is equipped with multiple slurry test loop systems and a variety of instrumentation to execute both pump and pipeline performance testing on water and slurry.

To duplicate the expected make-up of the slurry, GIW engineers added four-inch solids to the sand and ran it through a barrage of tests on pumps made of Gasite WD28G.

GIW manufactures this abrasion-resistant high-chromium white iron with chemical additives and a specialized heat treatment. This refines its microstructure, making it harder (600 HBN/58HRC) and finer grained than most white irons. This metal is proving so superior in mining applications that it is quickly replacing rubber as the material of choice for slurry pumps.

Next, GIW engineers designed a customized pump for Syncrude's tailings application. They began with an LSA 18x20-44 and modified the hydraulics to handle the added pressure of the tailings operation. Syncrude employed a single variable frequency drive for three pumps in series. This adjusts the speed of all three pumps at the same time, which keeps the pumps running at the most efficient operating level, ensuring longer life and requiring less maintenance.

When GIW's lab tests indicated that these pumps would offer excellent service in the tailings application, Syncrude purchased 12 of them for the start-up of their Southwest Sand Storage Facility. The results were excellent. While the rubber-lined pumps had been providing only 2,000 hours of operation between preventative maintenance cycles, GIW's all-metal pumps are realizing 4,000 hours.

The Successful Tailings Application Led Syncrude To Consider Using All-metal Pumps For Hydrotransport
At the same time all this was taking place, Syncrude was further refining its hydrotransport technology for mining oil sands. In this new process, the oil sands are made into a slurry and transported to the processing plant via pipelines rather than on the traditional and more expensive conveyor belts.

Syncrude began by testing in small diameter pipelines in their research lab in Edmonton, Alberta. When that proved successful, they then decided to perform a large-scale prototype of the process.

At that point, Syncrude engineers designed their Extraction Auxiliary Production System (EAPS) Project. They began by using the rubber-lined pumps they had formerly used in their tailings operations. However, after seeing how well the GIW metal pumps worked in the Southwest Sand Storage Facility, Syncrude decided to test metal pumps for hydrotransport as well. They asked GIW to perform these tests.

Over the years, GIW has enjoyed considerable success in booster pump operations in the Florida phosphate industry, where slurries are often pumped as far as ten miles. Based on their experience there, GIW considered hydrotransport a viable option for Syncrude.

GIW engineers again tested tailings sand from the Syncrude mine in their Hydraulic Testing Laboratory, this time replicating the hydrotransport process. They made a slurry of the tailings sand, which did not contain the seven to nine percent oil found in oil sands, and tested it in the lab's pipelines. If they could pump the slurry without the oil, they knew they could pump it even more efficiently with it, as the oil would soften the slurry's erosive impact. Further, larger lumps were expected in oil sand hydrotransport slurry than in tailings slurry. Therefore, Syncrude felt that the metal pumps would outperform the rubber-lined ones because they could better withstand the slurry's erosive impact.

The test offered such positive results that Syncrude decided to try the metal pumps in their EAPS project. Working with GIW engineers, they applied three of the GIW metal pumps, without the variable frequency drive, in a series. This enabled them to successfully pump oil sands, further demonstrating the feasibility of hydrotransport. In fact, the GIW pumps have been operating effectively at the EAPS project for three years now.

Based on these findings, Syncrude has decided to use all-metal pumps in both tailings and hydrotransport operations. They estimate that this elegant and simple process will save them two dollars on each barrel of oil they process.

GIW's Engineers Can Help You Find Innovative Solutions To Your Toughest Slurry Pumping Problems
This technological breakthrough proves, once again, that there is simply no substitute for GIW's expertise. For over a century now, GIW's engineers and designers have helped customers find cost-effective solutions to their slurry pumping problems. Solutions that have revolutionized the slurry pump industry and kept GIW on the cutting edge of slurry pump technology.

For more information on GIW's engineering, design and testing services, please call (706) 863-1011, Ext. 2272, or send an e-mail to sales@giwindustries.com.