We pulled on overalls, stepped into high rubber boots, donned hardhats, checked our lamps and got into Mine Foreman Reg Swain’s new Toyota Jeep. As daylight faded behind us, our eyes adjusted to the green and amber lights on the dashboard. Outside the glassed-in cab, the dusty beams of light from the headlights swept across the rock walls of the spiral ramp as we descended under Trout Lake. By the time we had gone down 300 m and climbed the short attack ramp into the 3321 stope, we could sense we were well inside the troughs of a great mining machine. It was the first day of a 3-day visit to Flin Flon, Man. and the mining and milling operations of Hudson Bay Mining & Smelting. We had chosen to visit HudBay because little has been published regarding this major zinc, copper (and, in the near future, nickel) miner in recent years and we knew there was an important story to be told. With direct mining costs in August totalling just $19.86 per ton, the Trout Lake mine (a joint venture between HudBay, Granges Exploration, Manitoba Minerals and Outokumpu Oy) is a showpiece of HudBay’s operating prowess. The stench of diesel exhaust filled the air and the roar of an 8-cu-yd scoop bounced off the walls of the cut-and-fill stope — one of the two most prolific of the mine’s four active mining areas. We were about to see what makes this one of the lowest- cost cut-and-fill mines anywhere.
Superintendent Brian Murphy says there are only two other mines in the world — one in Finland and one in Australia — which even come close to Trout Lake’s average of about 4.2 tons per man hour. He attributes the mine’s high productivity not to orebody geometry or grade (tons per vertical foot are not spectacular) but to the competence of the men working here and the machines they use. Those machines include an all-diesel fleet of six trucks and three scoops (with one more on order) manufactured in Finland by Toro.
As the scoop operator filled his bucket with massive sulphides rich in sphalerite and chalcopyrite with minor pyrite and pyrrhotite, a second operator jockeyed his huge 40 tonne Toro truck into position to receive the load. The welded steel box frame of the truck was hinged in the middle, giving it added manoeuvrability in the tight confines of the stope. As the bucket of the 500 D scoop went up about 4 m in the air, the truck backed into position under it with a roar of its 240-kW, V-12 engine. The scoop operator dumped his payload and the truck roared out from under the empty bucket. Three more bucket-loads would fill the truck, ending the carefully timed dance of these two diesel giants. Then it roared out of the stope and up the 13% grade of the ramp at a snail’s pace under the weight of about 40 to nnes of ore.
On an average 12-hr shift, each operator makes 10 or 11 trips up this ramp to a dump located in an underground opening blasted out of a hill on the shore of Trout Lake. With four trucks running on each 12-hr shift, 24 hrs a day, the 97 men at Trout Lake move 2,300 tons of ore to the crusher dump every day. A scale weighs each truck before it dumps. From there, the minus 6-inch ore is conveyed up a 25% incline to surface where it is transported through an elevated gallery to the top of the load-out building. Two 300-ton bins hold the ore until surface trucks haul it to the mill in Flin Flon.
With the truck gone from the stope, the scoop operator opened the door to his air-conditioned and noise insulated cab (which reduces noise levels to 80 dba), shut off his cassette deck and grabbed a bite to eat before the next truck came. We got a real sense that time is used wisely here — no time for breaks in a lunchroom. There is a constant roar of machines and a go-go-go attitude. On the wall just inside the shifter’s office on surface we find out why. Everything is geared to moving tons. The target in 1988 is 800,000 — the most of any previous year since the mine went into production in 1981. A total of three million tons at an average grade of 4.63% zinc, 2.11% copper and 0.051 oz gold and 0.42 oz silver per ton has been mined from the deposit so far. Daily targets are plotted on graphs a month in advance for each of the four crews and actual production figures are plotted each day for crews to see where they stand each day before they go underground. “If crew-members see that they’re below the line at the end of the month, they’ll give ‘er,” Murphy says. Bonus cheques for each crew-member is based on how far above the line he is. That way, too, no one man on a crew can “dog it,” Murphy says, because he drags the rest of his crew down with him.
This self-regulating system appears to be paying off. Although HudBay is hauling ore from greater and greater depths each year, productivity has not declined as common sense would suggest. Despite the fact that these trucks are hauling ore farther than in previous years, productivity is actually on the up-tick. Costs, too, are staying down. Even with the bonuses, total truck and scoop operating costs are just $2.53 per ton — about the same as they were in 1982-83, according to General Manager John Ross. Maintenance is the largest single cost item, at $6.21 per ton.
All equipment is serviced in an underground service bay 10 m above lake level in the same hill that hosts the crusher station. If there is one thing about the design of the mine that Murphy would like to change, it is this service bay. Although it was a good idea in the beginning, space has been at a premium since March, 1986 when the company replaced its fleet of 5-cu-yd scoops and 27-ton trucks with the bigger Toro units. The shop is 50 m long, 15 m wide and 10 m high. It has four service entrances and a walkway from the main portal. Thirteen mechanics and four electricians work here to keep the production machines in top shape. A concrete lubrication ramp has been constructed above floor level and a clean room was built at the same end of the shop for hydraulic drill repair. Besides the fleet of mucking machines, the maintenance crew also has to deal with three 2-boom electric-hydraulic jumbo drills (one from Tamrock and two from Eimco-Jarvis-Clark), a one-boom jumbo from Eimco-Jarvis-Clark, a Volvo utility vehicle and two electric- hydraulic roof-bolters for installing 8-ft mechanical bolts. A warehouse is adjacent to the shop. It stacks mainly mechanical components for mine equipment, with some electrical and mine operating supplies. The warehouse is staffed on day shifts only. Stock control and material acquisition are aided by a computer link with central inventory in the main Flin Flon warehouse. An electrical repair room and a pump repair bay are also near the main shop. “We have visitors in here all the time,” Murphy says. “And they’re often surprised by how simple our methods are.” A good example is the fill fences in the stopes. We climbed up one in the 3322 stope at the other end of the most productive area of the mine. It was nothing elaborate, just a dam of waste rock dumped on the fill floor — no elaborate timber structures lined with fabrine. This way about 99% of the waste rock is used underground. Mine contractors Thyssen Mining & Construction out of Regina use a raisebore machine to drive fill raises, 5 ft in diameter up to the upper level. Trucks bring classified mill tailings (with a moisture content of about 35%) in on the top level and dump it down the raises into the stopes, Murphy explains. On surface we see where the haulage trucks bring the mill tailings to the mine from the mill in Flin Flon. The bottom-dump vehicles dump their sloppy loads into a surface slurry box; then the truck picks up a load of ore to take back to Flin Flon. The mill tailings are combined in the slurry box with screened sand from a local quarry. Then the fill feeds into underground cones via a raise 2 ft in diameter. From there, it is hauled by the underground trucks out under the lake to the fill raises. No cement is used in the fill — a feature which also contributes to lower costs. To give the scoops (which weigh about 33 tonnes each) and the trucks (which weigh about 25 tonnes) a solid base off which to work, the operators leave about 3 ft of ore on the stope floor. Then when it comes time to fill a 15-m lift (i.e. when the stope is all mucked out), that 3-ft layer of ore is mucked out.
Another example of how this mine keeps down costs can be seen in the backs of the stopes. To reduce overbreak and therefore keep the scaling and bolting part of the mining cycle to a minimum, HudBay uses a Dupont blasting agent to preshear the holes around the perimeter of a working face. The product is called TRIMTEX and is loaded in the holes closest to the back. “We’ve tried other products, but this TRIMTEX seems to do the best job for us,” Murphy says.
Mining at Trout Lake is rapidly advancing through the series of ore lenses which have been identified so far (about five in total). The two main lenses, which contain 4.8 million tons of ore yet to be mined at an average grade of 5.9% zinc and 2.04% copper, are called the North and South zones. The South zone has been completely delineated by exploration drilling, but the larger North zone may still be open at depth, according to HudBay’s vice-president, exploration, Alastair Walker. Six holes below the 450-m level intersected some nice values (5% copper over 6 m), so the joint-venture partners approved a major $18-million shaft-sinking project, early in 1987.
When the shaft is deepened to 560 m sometime late this year, the hoist-room will be sealed and pressurized to prevent the build-up of dust. Designed to hoist only skips loaded with ore (there are no manways in the shaft), this facility will be fully automated to hoist the ore HudBay expects to find below the 450-m level. The ramp has to be extended to the 560-m level and a drift has to be driven to connect it to the shaft before that ore can be hoisted. The contract for this lateral development has not been let, but it should take about two years to complete.
In the meantime, the fleet of Toro trucks will continue to wind its way up the ramp at Trout Lake and the crews will continue to keep a close eye on their day-to-day performance charts, keeping those tons per manshift up there for all in the industry to admire.
We pulled on overalls, stepped into high rubber boots, donned hardhats, checked our lamps and got into Mine Foreman Reg Swain’s new Toyota Jeep. As daylight faded behind us, our eyes adjusted to the green and amber lights on the dashboard. Outside the glassed-in cab, the dusty beams of light from the headlights swept across the rock walls of the spiral ramp as we descended under Trout Lake. By the time we had gone down 300 m and climbed the short attack ramp into the 3321 stope, we could sense we were well inside the troughs of a great mining machine. It was the first day of a 3-day visit to Flin Flon, Man. and the mining and milling operations of Hudson Bay Mining & Smelting. We had chosen to visit HudBay because little has been published regarding this major zinc, copper (and, in the near future, nickel) miner in recent years and we knew there was an important story to be told. With direct mining costs in August totalling just $19.86 per ton, the Trout Lake mine (a joint venture between HudBay, Granges Exploration, Manitoba Minerals and Outokumpu Oy) is a showpiece of HudBay’s operating prowess. The stench of diesel exhaust filled the air and the roar of an 8-cu-yd scoop bounced off the walls of the cut-and-fill stope — one of the two most prolific of the mine’s four active mining areas. We were about to see what makes this one of the lowest- cost cut-and-fill mines anywhere.
Superintendent Brian Murphy says there are only two other mines in the world — one in Finland and one in Australia — which even come close to Trout Lake’s average of about 4.2 tons per man hour. He attributes the mine’s high productivity not to orebody geometry or grade (tons per vertical foot are not spectacular) but to the competence of the men working here and the machines they use. Those machines include an all-diesel fleet of six trucks and three scoops (with one more on order) manufactured in Finland by Toro.
As the scoop operator filled his bucket with massive sulphides rich in sphalerite and chalcopyrite with minor pyrite and pyrrhotite, a second operator jockeyed his huge 40 tonne Toro truck into position to receive the load. The welded steel box frame of the truck was hinged in the middle, giving it added manoeuvrability in the tight confines of the stope. As the bucket of the 500 D scoop went up about 4 m in the air, the truck backed into position under it with a roar of its 240-kW, V-12 engine. The scoop operator dumped his payload and the truck roared out from under the empty bucket. Three more bucket-loads would fill the truck, ending the carefully timed dance of these two diesel giants. Then it roared out of the stope and up the 13% grade of the ramp at a snail’s pace under the weight of about 40 to nnes of ore.
On an average 12-hr shift, each operator makes 10 or 11 trips up this ramp to a dump located in an underground opening blasted out of a hill on the shore of Trout Lake. With four trucks running on each 12-hr shift, 24 hrs a day, the 97 men at Trout Lake move 2,300 tons of ore to the crusher dump every day. A scale weighs each truck before it dumps. From there, the minus 6-inch ore is conveyed up a 25% incline to surface where it is transported through an elevated gallery to the top of the load-out building. Two 300-ton bins hold the ore until surface trucks haul it to the mill in Flin Flon.
With the truck gone from the stope, the scoop operator opened the door to his air-conditioned and noise insulated cab (which reduces noise levels to 80 dba), shut off his cassette deck and grabbed a bite to eat before the next truck came. We got a real sense that time is used wisely here — no time for breaks in a lunchroom. There is a constant roar of machines and a go-go-go attitude. On the wall just inside the shifter’s office on surface we find out why. Everything is geared to moving tons. The target in 1988 is 800,000 — the most of any previous year since the mine went into production in 1981. A total of three million tons at an average grade of 4.63% zinc, 2.11% copper and 0.051 oz gold and 0.42 oz silver per ton has been mined from the deposit so far. Daily targets are plotted on graphs a month in advance for each of the four crews and actual production figures are plotted each day for crews to see where they stand each day before they go underground. “If crew-members see that they’re below the line at the end of the month, they’ll give ‘er,” Murphy says. Bonus cheques for each crew-member is based on how far above the line he is. That way, too, no one man on a crew can “dog it,” Murphy says, because he drags the rest of his crew down with him.
This self-regulating system appears to be paying off. Although HudBay is hauling ore from greater and greater depths each year, productivity has not declined as common sense would suggest. Despite the fact that these trucks are hauling ore farther than in previous years, productivity is actually on the up-tick. Costs, too, are staying down. Even with the bonuses, total truck and scoop operating costs are just $2.53 per ton — about the same as they were in 1982-83, according to General Manager John Ross. Maintenance is the largest single cost item, at $6.21 per ton.
All equipment is serviced in an underground service bay 10 m above lake level in the same hill that hosts the crusher station. If there is one thing about the design of the mine that Murphy would like to change, it is this service bay. Although it was a good idea in the beginning, space has been at a premium since March, 1986 when the company replaced its fleet of 5-cu-yd scoops and 27-ton trucks with the bigger Toro units. The shop is 50 m long, 15 m wide and 10 m high. It has four service entrances and a walkway from the main portal. Thirteen mechanics and four electricians work here to keep the production machines in top shape. A concrete lubrication ramp has been constructed above floor level and a clean room was built at the same end of the shop for hydraulic drill repair. Besides the fleet of mucking machines, the maintenance crew also has to deal with three 2-boom electric-hydraulic jumbo drills (one from Tamrock and two from Eimco-Jarvis-Clark), a one-boom jumbo from Eimco-Jarvis-Clark, a Volvo utility vehicle and two electric- hydraulic roof-bolters for installing 8-ft mechanical bolts. A warehouse is adjacent to the shop. It stacks mainly mechanical components for mine equipment, with some electrical and mine operating supplies. The warehouse is staffed on day shifts only. Stock control and material acquisition are aided by a computer link with central inventory in the main Flin Flon warehouse. An electrical repair room and a pump repair bay are also near the main shop. “We have visitors in here all the time,” Murphy says. “And they’re often surprised by how simple our methods are.” A good example is the fill fences in the stopes. We climbed up one in the 3322 stope at the other end of the most productive area of the mine. It was nothing elaborate, just a dam of waste rock dumped on the fill floor — no elaborate timber structures lined with fabrine. This way about 99% of the waste rock is used underground. Mine contractors Thyssen Mining & Construction out of Regina use a raisebore machine to drive fill raises, 5 ft in diameter up to the upper level. Trucks bring classified mill tailings (with a moisture content of about 35%) in on the top level and dump it down the raises into the stopes, Murphy explains. On surface we see where the haulage trucks bring the mill tailings to the mine from the mill in Flin Flon. The bottom-dump vehicles dump their sloppy loads into a surface slurry box; then the truck picks up a load of ore to take back to Flin Flon. The mill tailings are combined in the slurry box with screened sand from a local quarry. Then the fill feeds into underground cones via a raise 2 ft in diameter. From there, it is hauled by the underground trucks out under the lake to the fill raises. No cement is used in the fill — a feature which also contributes to lower costs. To give the scoops (which weigh about 33 tonnes each) and the trucks (which weigh about 25 tonnes) a solid base off which to work, the operators leave about 3 ft of ore on the stope floor. Then when it comes time to fill a 15-m lift (i.e. when the stope is all mucked out), that 3-ft layer of ore is mucked out.
Another example of how this mine keeps down costs can be seen in the backs of the stopes. To reduce overbreak and therefore keep the scaling and bolting part of the mining cycle to a minimum, HudBay uses a Dupont blasting agent to preshear the holes around the perimeter of a working face. The product is called TRIMTEX and is loaded in the holes closest to the back. “We’ve tried other products, but this TRIMTEX seems to do the best job for us,” Murphy says.
Mining at Trout Lake is rapidly advancing through the series of ore lenses which have been identified so far (about five in total). The two main lenses, which contain 4.8 million tons of ore yet to be mined at an average grade of 5.9% zinc and 2.04% copper, are called the North and South zones. The South zone has been completely delineated by exploration drilling, but the larger North zone may still be open at depth, according to HudBay’s vice-president, exploration, Alastair Walker. Six holes below the 450-m level intersected some nice values (5% copper over 6 m), so the joint-venture partners approved a major $18-million shaft-sinking project, early in 1987.
When the shaft is deepened to 560 m sometime late this year, the hoist-room will be sealed and pressurized to prevent the build-up of dust. Designed to hoist only skips loaded with ore (there are no manways in the shaft), this facility will be fully automated to hoist the ore HudBay expects to find below the 450-m level. The ramp has to be extended to the 560-m level and a drift has to be driven to connect it to the shaft before that ore can be hoisted. The contract for this lateral development has not been let, but it should take about two years to complete.
In the meantime, the fleet of Toro trucks will continue to wind its way up the ramp at Trout Lake and the crews will continue to keep a close eye on their day-to-day performance charts, keeping those tons per manshift up there for all in the industry to admire.
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