Note the source: "Oilsands Review", so take not too much comfort in their pronunciations nor forget that much isn't spoken of in the article on the "improvements" in procedure just yet. Nonetheless, it's worth reading and familiarizing ourselves with.
--M
The changing face of oilsands mining
Mobile crushing systems on the way
http://www.oilsandsreview.com/articles.asp?ID=401
Diane L.M. Cook
Jun 2007
The landscape of the oilsands mining sector is rapidly changing, and so too is the technology to process the tons of ore. Oilsands operators can now choose a new mining technology – mobile crushing - to use at their mine sites, depending on a number of factors. As part of its next expansion – Voyageur South – Suncor has announced it will start to replace some of its truck and shovel fleet with these mobile units.
In traditional truck and shovel technology, a shovel loads large heavy hauler trucks with oilsand and transports it to a crusher. The crusher begins the processing by breaking the ore down into small pieces that are then transported by conveyor for further processing and extraction of the bitumen.
With a mobile crushing system, or MCS, the crusher is moved right to the mine face where it is continuously loaded directly by the shovel. The ore is crushed on the spot and then, as with current technology, is transported by a mobile conveyor for further processing.
There are only two manufacturers that currently build MCS for the oilsands sector; MMD Mineral Sizing (Canada) and Krupp Canada. MMD Canada recently built Suncor’s first fully mobile crushing unit, and Krupp is in the process of building MCS for Albian Sands, and Syncrude Canada.
MMD Mineral Sizing
Located in the heart of the Athabasca oilsands region in Fort McMurray is MMD Mineral Sizing (Canada), part of the worldwide MMD Group of Companies.
“We have been working diligently with Suncor since 1992, and we continue to perfect our sizing technology based on previous experience in the field and from previous installations of our sizers at Suncor, Syncrude, and Albian’s mine sites,” says Richard Scrimshaw, vice president and general manager.
MMD Canada has designed and built the MMD 1500 Series OS1 Fully Mobile Sizing Plant, known as the MMD OS1, for Suncor. The MMD OS1 has a rated capacity of 5,500 tonnes per hour to match the capacity of the large electric rope shovel which feeds the unit.
The first MMD 1500 series stationary sizers were supplied in 1993 to operate within the oilsands industry as part of the switch to short haul truck and shovel mining technology from bucket-wheels and draglines. Scrimshaw says the MMD 1500 series sizer is presently the highest capacity unit available. However, design studies are underway for higher capacity sizers for future installation in the oilsands industry.
High reliability, low wear and low maintenance costs are always key features in any mining operation, but are crucial in the highly abrasive oilsands and sometimes environmentally hostile oilsands industry.
Krupp Canada
The materials handling division within the ThyssenKrupp conglomerate specializes in the design and supply of open pit mining equipment and is the largest supplier of mobile crushing systems worldwide. The company has built over 100 MCS for a variety of mining applications for numerous clients around the world.
Krupp Canada, the Canadian subsidiary of ThyssenKrupp located in Calgary, specializes in designing mining equipment for the oilsands industry. The company has provided large semi-mobile crushing systems to all of the oilsands mines, and reports it is currently discussing mobile mining concepts with several oilsands operators.
Using a new technology
As with any new technology, there are benefits and challenges. Tim Joseph conducts and teaches mining equipment related research at the University of Alberta. He says one of the benefits of MCS is that it will result in a reduction in ground stability issues associated with traditional large mobile truck and shovel mining technology.
Joseph explains how oilsands operators can realize the benefits of using a MCS. “When an oilsands operator uses large mobile surface mining equipment such as a MCS, it means a reduction in the number of trucks the company has to purchase for traditional truck and shovel mining technology. Fewer trucks means a reduction in capital, maintenance, fuel costs and the road maintenance required. As well, given the current people shortage in the mining industry, using single stream mobile surface mining equipment means operators can reduce their labour force.”
However, Joseph says MCS technology is still in the early proving stages as oilsands operators and manufacturers work closely together to address the challenges of mining ore of varying bitumen content and under varying climatic conditions.
“Because [the ground in the oilsands] decreases in stability with increasing ambient temperature and bitumen content, there are still a few kinks to work out with the new technology. Ground instability is a big factor in mining oilsands with any large mobile surface mining equipment that puts down a small footprint in proportion to its weight,” he explains. “Add in the normal operational motions and vibrations and the effect is akin to patting your hand on wet sand at a shoreline – your hand sinks into the wet sand. The sheer size and weight of a unit means it can, under adverse conditions, deform the ground surface and sink.”
Manufacturers of traditional truck technology are working on alternative tire and suspension concepts that may alleviate some of the stability issues that have led to a more favourable view of MCS as a recent alternative technology. Joseph says known experience with fixed crushers and screens in oilsands processing has identified oilsand density and viscosity issues around material flow. This is an issue that would also affect the performance of a MCS.
Joseph cautions that although MCS might be a viable option for some oilsands operators, single mobile mining equipment is a single stream system, which means if it stops for any reason the entire flow of material from a given pit area also stops. Having multiple mobile units allows for one unit to stop and the overall flow of material continues.
Already on site
Three major oilsands operators are already using MCS. Although some of the technology is proprietary, the basic construct of the systems is not.
Albian Sands has been using a semi-mobile crushing plant manufactured by Krupp since 2002. This particular semi-mobile MCS has a capacity to accept 1,200 tonnes of mined oilsand at a time and can process 14,000 million tonnes per hour.
Chris Zorica, manager of public affairs at Albian Sands, says “We continue to look at various types of technology to improve our mining process, both from an economical and an environmental standpoint.”
Syncrude Canada is also looking at using new MCS technology to mitigate common oilsands-related environmental issues.
“Syncrude has been in operations for 30 years and the company prides itself on being innovative in the use of leading-edge technologies in our oilsands operations,” says spokesman Alain Moore.
Syncrude is currently testing compact slurry preparation technology. The vision is for shovels to feed oilsands directly into a MCS and then into the in-pit bitumen production system slurry equipment. The company has been testing the new technology since 2006 in a pilot project at its North mine.
Suncor Energy is currently testing a MCS on a commercial scale. Although some portions of the unit are designed by MMD, much of the system is Suncor’s proprietary technology.
“Mobile mining systems are an example of Suncor and the oilsands industry’s constant drive for technological innovation. We expect to use this new mobile mining technology to strengthen our operational performance and to mitigate socio-economic and environmental concerns that are synonymous with oilsands development,” says Brad Bellows, a company spokesman.
The mobile mining equipment currently in operations at Suncor’s mine site cost $150 million. Due to the size of the unit, it was constructed on site and it took about 18 months to construct. The unit Suncor is testing right now has been running at 5,500 tonnes of ore per hour. This is the equivalent of close to 15 loads of ore in the largest trucks which have a capacity of 380 tonnes each.
“With the growth of our mining operations, and the steady march of the mine face away from processing facilities, we would require many more heavy hauler trucks if we continue to use only truck and shovel operations. As well as the capital cost of the trucks, this would mean a corresponding increase in maintenance costs and workforce with about 10 operations and maintenance personnel per truck.”
Bellows says this unit has performed very well in both summer and winter operating conditions. The seasonal variation from highs of +35 degrees Celsius in the summer to lows of -35 degrees Celsius in the winter is the biggest test of new equipment in northern Alberta.
“With the success we’ve seen so far, we now have plans for five more units to be in operation over the next five years. There are always refinements that need to be made when a new technology is introduced and we expect further tweaking of this mobile mining technology as we move forward.”
Bellows says with Suncor’s new proposed Voyageur South mine, the company expects to begin to replace part of its truck and shovel mining fleet in favour of MCS.
However, he explains trucks will continue to be part of Suncor’s operations as they expect to use heavy haulers to transport overburden in mines that are using mobile mining equipment for ore transportation.
The oilsands sector’s three largest operators continue to use existing semi and mobile MCS with the goal of perfecting the new mining technology to further mitigate the environmental and socio-economic challenges from oilsands mining.
