Skip hoists have been automated for some time, and it should known by this fall whether or not government officials in Ontario will approve the use of microprocessor-based systems on cage hoists.
A fully automated microprocessor-controlled mine hoist monitoring system was displayed for the first time in North America at the Canadian Institute of Mining and Metallurgy trade show in Ottawa last May.
Designed by Bruno Leijon, product manager of Asea Brown Boveri of Saint-Laurent, Que., the Hoist Monitor (or UHM-100) is being tested at the Kidd Creek mine in Timmins, Ont. as a replacement for electromechanical controls called Lilly controllers, which are currently supplied by the Ontario Ministry of Labour.
“The government of Ontario has agreed to allow our system to run for 2,000 hours on a 2-skip hoist at Kidd Creek and if no unsafe situations arise, then it will be approved for the cage hoist,” Leijon says. Falconbridge Ltd. has purchased four units, the first of which was installed on the skip hoist at the end of July.
The centrepiece of the system is a MasterPiece 100 computer, which acts as a watchdog, checking system functions every three seconds. Should something go wrong and the hoist come to an emergency stop, the system would provide a wealth of information on what happens during the emergency stop. The Lilly controller gives no such information.
Among other things, the system guarantees that the hoist is not running at overspeed at the end of its run. End speed profiles can be programmed to match particular applications and the position determination accuracy is in the range of fractions of an inch.
The system, which took about one full year to design and build after almost three years of conceptual design, offers considerable operating and capital cost savings over the Lilly controller, Leijon says. The system will likely be priced lower than the Lilly controller.
Fiatallis Lubricants
Lubricants formulated to meet the requirements of Fiatallis’s 5,000-hr., 2-year powertrain warranty have been introduced by the company.
They include premium engine oil, premium antiwear hydraulic fluid, heavy-duty gear lube, premium Lithium grease and a premium multi-purpose equipment fluid.
The company also has an oil-sampling program whereby samples can be shipped to a Fiatallis lab for analysis. The company recommends sampling be performed every time fluids are changed in a machine.
High-pressure Seals
Seals, designed to reduce friction at high pressure on rotary swivels and couplings, valve stems and rotary actuators, are available from Nortesco Inc. of Dorval, Que.
The advanced design of Lotork, as the seals are called, consists of an elastomeric energizer shrouded in a shell. The closed side of the seal faces the applied pressure and responds automatically, giving total chemical protection over a temperature range from about -25degC to +180degC.
New Flow Meters
A series of flow meters has been introduced by McMillan Co. Called the Series III, the new meters operate on the pelton turbine wheel principle and come in eight rangers covering flow rates from 13 ml per minute to 10 litres per minute.
Accuracies of up to = or -1% F.S. and turndown ratios up to 50:1 are specified.
Hydrofoil for Bioleaching
A gas dispersion hydrofoil, designed specifically for agitators in the only commercial biological gold ore pretreatment plant in North America, has been developed by Mixtec.
Called the BX04, the hydrofoil efficiently disperses gas in slurry.
Mixtec has also introduced the advanced hydrofoil impeller system, the HA703. The patented impeller slot design causes a supply of additional energy to the boundary layer, which prevents the formation of a reversal of the pressure gradient. Consequently, pumping rates, in-tank mixing velocities and effective volume are increased, a company release says.
Mixtec offers a range of conventional impellers selected for each application, including marine type, flat and pitchch blade turbines and hydrofoils.
The company’s mixing technology is available in Canada through Mixtec (Canada) in Vancouver.
Conveyor Maintenance Tools
A cordless power tool, suitable for splicing conveyor belts, repairing rips and making replacements to fastener plates, is available from Flexible Steel Lacing Co. of Illinois.
The 17-lb. (7.6-kg) kit cuts installation times in half when compared with hand tools. The kit includes a 1/2-inch impact tool, three rechargable batteries, one recharge unit, two bolt-breaking tools, a power punch, a power wrench and quick-change chuck.
Tophammer Guide
A guidance system for tophammer drills, which virtually eliminates the risks of costly deviations in drill holes, has been introduced by Sandvik Rock Tools North America of Montreal.
The system consists of a special guide bit and guide rod that are used to lead the drill string. The guide bit has a long, fluted skirt and shrink-fitted cemented carbide buttons set in a concave face together with chisel-shaped buttons around the periphery.
A guide rod is used at the front of the drill string. This makes up a rigid, 3-point guidance system that produces exceptional results even in upwardly inclined holes.
The system does not affect penetration rates and can be used on rigs with a mechanized rod-handling system, Sandvik reports.
Oxygen Analyzers
A complete line of fixed and portable digital oxygen analyzers (5900 Series) is available from Neutronics Inc. of Exton, Pa.
The units, which measure from 0.1% to 0.65% oxygen, offer control and alarm capabilities through milli-amp or milli-volt outputs or through thumbwheel closures.
An intrinsically safe oxygen sensor may be mounted up to several hundreds of metres from the analyzer to provide remote display or a cheap alternative to explosion-proof enclosures.
The sensor is packaged to ensure reliability in the harshest conditions.
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