Engine Air Filters Offer New Design, Better Performance
Baldwin Filters says its new Channel Flow air filters feature a design that provides a stronger, more reliable filter, with one of the key features being the filter element, which is environmentally friendly and fully incinerable. Channel Flow media is formed by layering alternating rows of flat sheets and corrugated media. Air enters an open channel on the inlet side, flows through the media and exits through an adjacent open channel—contaminants remain trapped within the channels and won’t dislodge during servicing. This media is inherently strong, according to Baldwin, thus eliminating the need for the center tube and metal wrappers used in traditional air filters. Channel Flow air filters also feature a durable frame, which in addition to enclosing the media pack and protecting it from damage during handling, also prevents air from being drawn in through the sides of the filter, adding an extra element of protection for the engine. Baldwin also has added a stronger media support to provide protection from increases in differential pressure. www.baldwinfilter.com
U.S. Steel first discovered NorthMet in the late 1960s, initially targeting high-grade mineralization at depth before moving up dip into lower-grade material that outcropped. However, prior to the autocatalyst market and significant industrial demand for platinum group metals, the only metals of relevance were copper and nickel—and nickel contamination of copper concentrate made the economics of existing flotation technology unattractive. U.S. Steel, after conducting widely spaced drilling along the deposit’s 3-mile strike length, ultimately sold an automatically renewable 20-year lease for it to PolyMet in 1989.
In December 2006, Polymet closed an additional purchase from Cleveland Cliffs that included a railroad connection linking the mine development site and the Erie plant, plus a 120-railcar fleet, locomotive fueling and maintenance facilities, water rights and pipelines, administrative office facilities at the site, and approximately 6,000 acres to the east and west of and contiguous to PolyMet’s existing tailing facilities—adding extra tailings storage capacity should the company choose to expand its production in the future. These assets cost Polymet another $15 million and 2 million shares, giving Cleveland Cliffs ownership of about 7.7% of Polymet’s issued stock.
The Erie plant, built in the 1950s for about $350 million, is an enormous facility—the main concentrator building alone is one-quarter mile long—that was originally designed to process 100,000 t/d of tough taconite ore. It includes a railcar dumper building; dual primary, secondary, tertiary and quaternary crushing lines; a large number of rod and ball mills; and a large magnetic separation section that will be superseded by a new flotation circuit.
Joseph Scipioni, Polymet’s COO, is confident that the plant, which has been idle since 2001, can be restarted without major mechanical difficulty. But as Scipioni, who formerly was plant manager at U. S. Steel Corp.’s taconite plant in Keewatin, said last fall, “Since we only plan to run the plant at one-third of its capacity, we’ll have plenty of spare parts available no matter what.” An existing pellet plant on site is being demolished. Polymet is installing a new flotation circuit inside the existing plant building and also plans to construct a new hydrometallurgical plant. It will sell a bulk concentrate from the flotation section to fund construction and commissioning of the hydromet plant which, when completed, will produce copper cathode, nickel-cobalt-zinc hydroxides or purified hydroxides of each metal, a gold/PGM precipitate for toll smelting, and synthetic gypsum which will be a by-product of the pressure leaching technology employed by the plant.
The project’s DFS projected a mining rate of 81,000 t/d of rock over the life of mine, with 32,000 t/d of ore delivered to the mill via the rail link. Mining costs presented in the DFS are $1.14/t of rock mined and $3.13/t of ore, but Polymet executives feel that these early-estimate figures are probably on the high side. The project staff has been examining opportunities for mining plan optimization and, according to the company, has been able come up with improvements that streamline pit scheduling, lower unit mining costs, reduce the overall strip ratio and extend reserve life. Mine preparation, including prestripping, will be handled by a contractor; Polymet will take over for full-scale operations, employing two large shovels and seven or eight 240-ton-capacity haul trucks. The final operational mine plan will be completed in parallel with the final stages of the permitting process
Ore from the mine, after arriving at the plant by rail, will be unloaded into the coarse crusher dump pocket and subjected to four-stage crushing—using only about one-fourth of the facility’s total crushing capacity—down to a product sized at 80% minus 0.5 in. followed by rod and ball mill grinding to a coarse sandy texture of 100- 125 µm P80. Prior to commissioning of the hydrometallurgical plant, Polymet plans to sell concentrates, either as a bulk product or as separate Ni and Cu concentrates with precious metal values present in both products. During the time it is selling the bulk concentrate, it will additionally process the flotation product through a scavenging circuit after the cleaner stage, following by regrinding, to remove more gangue material and produce a higher-grade concentrate. One of the company’s current objectives, according to David Dreisinger, a Polymet director and metallurgical processing consultant, is to increase copper content in the concentrate to more than 20% with less than 0.3% Ni content. Once the plant is operational, the company will process all concentrate using the Platsol process, which employs chloride-assisted pressure leaching to allow extraction of precious metals concurrently with the copper, nickel and cobalt. Platsol processing requires a conventionally designed autoclave operating at a moderately high temperature of 225°C and employing 30-60 g/L of H2SO4, and 10 g/L NaCl. At full production, Polymet intends to produce about 72 million lb/y cathode copper, 15 million lb/y of nickel, 700,000 lb/y of cobalt and more than 100,000 oz/y of combined precious metals.
Training for new and existing mobile hydraulics and industrial hydraulics installations is now available through Bosch Rexroth’s on-site training program. These customized training programs, according to the company, can improve operator skills, plant uptime and productivity. Each training course is designed to solve operational and system issues, eliminate offsite training costs and offer superior scheduling flexibility. Customizable on-site training gives employees an opportunity to expand their knowledge, on their schedule and within a specified budget, while customers who utilize the on-site service save on travel costs as Bosch Rexroth brings the courses to them. Employees receive training in proper start-up and preventive maintenance procedures from qualified Bosch Rexroth personnel. In addition to customized training, Bosch Rexroth also offers a series of regularly scheduled courses throughout the year to meet the needs of hydraulic systems maintenance personnel, engineers who are designing new systems, or those upgrading existing systems with new technology.
When compared with the world’s largest nickel/copper sulphide districts, various sources rank the Duluth Complex as third largest in nickel content, second in copper and second in PGM content. There are presently 13 known nickel/copper sulphide deposits in the Duluth Complex that combined, could host a theoretical resource of 4.4 billion tons of copper/nickel ore averaging 0.66% Cu and 0.20% Ni using a cutoff grade of 0.50% Cu equivalent. Not surprisingly, its economic potential has attracted a number of players.
The NorthMet project is by far the most advanced of its type in the area, but other companies are avidly pursuing exploration and development of additional polymetallic deposits throughout the Complex. Franconia Minerals Corp., an Alberta, Canada, company with its head office in Spokane, Washington, USA, holds more than 15,000 acres in the area and is focusing on its Birch Lake copper-nickel-PGM deposit located in the north-central part of the mineral belt. According to the company’s latest figures, Birch Lake contains resources of more than 100 million t grading 0.59% Cu, 0.19% Ni and 0.14 g/t Au, 0.65 g/t Pd and 0.32 g/t Pt. The company’s Maturi deposit, 3 miles to the north of Birch Lake, contains another 83.1 million t of similar but lower-grade mineralization, and its Spruce Road property is estimated to contain 124 million t of underground-minable and 376 million t of surface-minable inferred resources. Pre-feasibility studies are presently aimed at evaluating the viability of separate mines at Birch Lake and Maturi that would feed a single processing complex built near the Birch Lake deposit.
Another company active in the area is Ontario, Canada-based Duluth Metals, which reports that current estimated resources at its Nokomis deposit in the western portion of its Maturi Extension properties in the Duluth Complex consists of 347 million t of indicated resources grading 0.62% Cu, 0.20% Ni, and 0.52 g/t of platinum+palladium+gold (total precious metals, or TPM), plus an additional 108 million t of inferred resources grading 0.64% Cu, 0.18% Ni, and 0.70 g/t of TPM. In mid-January 2008, the company announced it had acquired a Platsol technology license from the process patent owner, International PGM Technologies Ltd., for future processing of these metals extracted from its properties along the Complex.
CanDig claims its Mining CD21 mini excavator is capable of digging 8 ft deep in the toughest of ground conditions and handling boulders that weigh up to a ton. The Mining CD21, according to the manufacturer, provides even more breakout force than some tracked excavators, employing a 9-hp Honda engine and 2.5–in-bore cylinders for extra digging power. At just 1,200 lb, it can be conveniently hauled either fully assembled, or by unfastening one large bolt (wrench provided) can be reduced to two loads of 700 lb and 500 lb, respectively. The load can be easily balanced with three convenient sling attachment points. The MiningCD21 can be configured with an 8-in.-wide trenching bucket or 20-in.-wide grading bucket. A ripper accessory allows users to dig through frozen or tough ground more easily and also doubles as a root cutter. The latest version of the Mining CD21also is fitted with a spare parts kit to reduce downtime in the field. www.candig.com
New Zealand Underground Mine Commissioned (Australia/Oceania)
OceanaGold Corp. on January 17 reported successful commissioning of the Frasers Underground mine at its Macraes operation on the South Island of New Zealand. This is the second new gold mine that the company has commissioned in the past 12 months, following startup of the Reefton mine; and according to OceanaGold, was completed on schedule, at a capital cost net of gold revenue of NZ$33.4 million. The company also plans development of two additional mines in the near future.
Frasers Underground has been developed on the down-dip extension of the orebody currently being mined via the Macraes open-pit. This new underground mine is scheduled to produce approximately 900,000 mt of ore in 2008 which will be processed through the Macraes processing plant. Frasers Underground concentrate represents about 16% of the total throughput for the Macraes autoclave with
the remainder coming from Macraes and Reefton concentrates. Underground development to date totals 6.5 km and will continue simultaneously as mining progresses. Exploration is ongoing and the company reports that results at depth continue to demonstrate strong continuity with numerous higher-grade areas defined.
John Kinyon, vice-president of New Zealand Operations commented, “We are pleased to have completed the Frasers Underground within our scheduled timeframe. Development rates exceeded our targets during 2007 and were able to access more ore faces than anticipated. As a result, Frasers has been scheduled to produce 900,000 tons of ore in 2008 versus the 800,000 tons anticipated in the project’s feasibility study. The addition of our third mine in New Zealand gives OceanaGold significant flexibility to achieve its 2008 production targets.”
OceanaGold previously announced in mid-December 2007 that it had successfully commissioned three new Outotec TankCell 300 flotation cells at the Macraes processing facility. Each TankCell 300 has a capacity of more than 300 m3 making it the world’s largest commercially operating flotation cell. The new installation of 300 m3 tanks combined with Macraes existing Outotec 150 m3 tanks replaced the site’s original two trains of column and conventional flotation cell which, according to the company, represents a significant reduction in process plant footprint and is expected to reduce maintenance and operating costs.
OceanaGold said it had achieved an initial increase in bulk flotation recovery of 4%, which exceeded the projected recovery increase of 2.5%. Based on the projected recovery improvement payback was 16 months, but is now expected to occur sooner following final commissioning of the complete circuit. By late December, OceanaGold expected that Macraes would be able to treat 6 million mt/y of ore.
The Macraes processing facility will treat all ore and concentrate produced at the Macraes, Frasers and Reefton mines.
Gemcom Software International Inc. has released a new, automated Underground Design module for its Gemcom Surpac software. Key benefits of the Underground Design module include: integration with the Surpac user interface, which provides powerful, flexible geology and planning features developed for ease of use; integration with Gemcom MineSched production scheduling; logical, visual design process using a flowchart-based approach; user-defined parameters are stored in a secure database, ensuring designs are both auditable and repeatable; and wide applicability to the diverse needs of different types of underground mines. According to Gemcom, by employing Surpac, the Underground Design module and Mine-Sched scheduling software together, mining companies can benefit from an integrated, end-to-end modeling, mine design, scheduling and analysis solution. With automation built into design and scheduling, mine planners are able to spend more time analyzing and improving end results. www.gemcomsoftware.com
Kolwezi Tailings Project to Proceed in DRC (Africa)
First Quantum Minerals announced that the board of Kingamyambo Musonoi Tailings SARL (owned by First Quantum, 65%; Gecamines, 12.5%; Industrial Development Corp. of South Africa, 10%; International Finance Corp., 7.5%; and the Government of the Democratic Republic of Congo, 5%) has committed to proceed with the development of the Kolwezi tailings project. First Quantum with support from its contributing equity partners of KMT (specifically IDC and IFC) will finance or procure third party debt project financing totaling up to $593 million. This satisfies the obligations of First Quantum, the IDC and the IFC to complete feasibility studies, carry out an environmental impact assessment, prepare an environmental management plan, and to obtain commitments with respect to the financing of the Project.
The base case for the Kolwezi project with a capital cost of $553 million is for a plant capable of treating 2.5 million mt/y of tailings throughput potentially producing 35,000 mt/y of copper cathode with the corresponding production of 7,000 mt of cobalt hydroxide. Tailings will be recovered utilizing high-pressure water monitors and will be pumped to the SX/EW treatment plant. The copper circuit will be based on proven SX/EW copper operations at Bwana Mkubwa and Kansanshi and the cobalt circuit will be based on plant processes similar to those operating at Mopani's Nkana cobalt plant.
Project construction completion is targeted for the third quarter of 2009 with commissioning taking place during the fourth quarter of 2009 and commercial production in the first quarter of 2010. The plant, which is targeted to initially produce 35,000 mt/y copper and 7,000 mt/y of cobalt hydroxide, will be designed and constructed such that plant capacity can be doubled at a capital cost of $40 million. Mine life is expected to be 22 years at an annual rate of 70,000 mt/y. Development of a cobalt metal facility and the expansion of copper and cobalt capacity are options that will be considered in the future.
Telsmith’s new line of inclined vibrating screens, the Vibro-King TL series, is intended to replace the existing Vibro-King and Specmaker screen lines, offering longer service life, reduced maintenance and lower operating costs. At the heart of the Vibro-King TL is the new TL shaft assembly featuring a "Never-Wear" seal design that eliminates contact seals, reducing maintenance and providing longer service life. For greater bearing life, all TL shaft assemblies utilize wide-series bearings and polished shaft bearing journals. Minimal maintenance is ensured via its large-diameter shaft casing that boosts oil volume to allow lower operating temperatures and fewer oil changes. For optimum efficiency, multiple flat and crowned deck designs are available allowing the Vibro-King TL to work with all screen media types. Also, deck spacing between the top and middle decks has been increased to simplify screen media changes.
Available in both single and dualshaft models and in sizes ranging from 5 x 14 ft up to 8 x 24 ft, the new Vibro-King TL line is available in both standard and heavy-duty models, with all HD models featuring half-inch-thick side plates. Spring mounts incorporate a "jacking bracket" providing safe, speedy access for spring maintenance. www.telsmith.com
OceanaGold on Track for 2009 Startup at Didipio Copper-Gold Project (Asia)
Oceana Gold Philippines Inc. (OGPI) is on track in the Didipio copper-gold project development in Nueva Viscaya, Philippines, with a road upgrade that has enabled it to transport mining equipment to a plant that will reportedly start up in early 2009. "We are on schedule with our development timeline. The road upgrade now allows us to get in large mining equipment and large infrastructure components to construct the plant," said OceanaGold CEO Steve Orr.
Before commissioning the plant, OGPI will begin pre-strip operations for the open-pit this year. "We will construct the process facility and do the pre-strip for the open-pit in 2008 before starting the commissioning phase in early 2009. The capital cost is expected to be about $5 million although we are still to complete the final engineering at which point we’ll be able to lock down definitive bids from suppliers," said Orr.
The company, listed with the New Zealand, Australian and Toronto stock exchanges, is bankrolling the project with a capital raised from at least these three countries.
The copper-gold project will have a yearly throughput of 2.5 million mt of ore from open pit and underground mining. Metal production is placed at 227,000 gold equivalent oz yearly during the first 10 years of production consisting of 142,000 oz of gold and 15,000 mt of copper concentrate.
OceanaGold, which has three mines in New Zealand believes its Philippine operation is important with the cost reduction results from here. "In 2008, we anticipate cash costs will be around $320/oz to $340/oz. By 2009 when Didipio is ramping up, we expect that to fall to around $215/oz to $235/oz due to the copper byproduct credit and the high-grade nature of the Didipio gold deposit," he said.
This will further go down to $175/oz to $195/oz when the local project runs at design capacity in 2009. "By 2011, we expect to generate $100 million in free cash flow based on a gold price of $500/oz and copper price of $1.90/lb."
The company is also spending $5 million in 2008 for exploration, particularly in Manhulayan in northern Surigao and in the Papaya prospect which is within its Nueva Vizcaya mining permit.
The copper production has a significant impact in cutting the company’s cash cost from the 2007 cash cost of $575/oz of gold "although this year is a redevelopment year for Macraes and we’ve been processing a significant amount of low-grade stockpile material, resulting in high cash costs. When Didipio is operating at full run rate, it’s going to be making about 50% of the gold-equivalent contribution to the company," Orr said.
The company earlier awarded engineering, procurement, construction and management works at Didipio to Ausenco Ltd.
Web Portals for X-Ray and Spectroscopy Information
Thermo Fisher Scientific has expanded its range of online resource centers with the addition of two new web entry portals for X-ray (www.thermo.com/xray) and Optical Emission Spectroscopy (www.thermo.com/oes). Visitors are able to access a complete overview of Thermo Scientific X-ray and OES instrumentation and its applications in the metals, mining, cement and petrochemical industries. In addition, users can download application notes and can sign up to receive specialist news resources including the popular Thermo Scientific Materials Analyst e-newsletter. Extensive service and support is also included, providing information on the provision of spare parts, training courses and help with support plans. An event section is also available which details the diary of upcoming shows relating to X-ray and OES. These web pages incorporate RSS feed capability for users who wish to be kept updated on Thermo Fisher’s OES and X-ray news. www.thermo.com
Eagle Nickel-Copper Project Takes Flight on Permit OK
Kennecott Eagle Minerals Co., a subsidiary of Rio Tinto Group’s Kennecott Minerals Co., based in Salt Lake City, Utah, USA, said it has received state regulatory approval of three principal environmental permits needed to launch construction of its Eagle nickel and copper mine in the state of Michigan’s Upper Peninsula, 30 miles northwest of Marquette. The Michigan Department of Environmental Quality (MDEQ) issued mine, air, and groundwater discharge permits, following an application review process that began in February 2006.
A two-year mine construction phase will begin in 2008. The company expects the mine to produce a total of roughly 300 million lb of nickel and 250 million lb of copper over its estimated six- to eight-year life. Capital cost for the project is estimated at $120 million.
Eagle’s mine permit is the first issued by Michigan under its 2004 nonferrous metallic mine law, considered among the most protective in the U.S. The three permits issued today contain extensive and specific compliance conditions consistent with requirements for ensuring safeguard of the environment and ecosystems.
Kennecott said it designed Eagle for “the smallest environmental footprint possible.” The mine will be underground, accessed through a portal located in the same area where a water treatment plant, ore loading equipment and other facilities will be contained to less than 100 acres. Ore will be processed off site.
The surface ore processing/crushing facility will consist of a coarse ore storage area, a crusher building, and a crushed ore building. Located within the crusher building will be a grizzly feeder, a rock breaker, a 30 x 40-in. jaw crusher, and two covered transfer points used to feed the crushed ore leaving the jaw crusher into the two crushed ore bins.
Underground, the mine’s primary stopes will be backfilled using a cement and waste rock or aggregate mixture. Waste development rock will be used for backfill in the secondary stopes. The cement backfill operations would be supported by cement and fly ash silos on the surface, each with a storage capacity of 120 t. From the silos, cement and fly ash would discharge via a screw conveyor into a blender. Once blended, the mixture would be discharged via a screw conveyor and rotary airlock into a borehole for delivery to the stopes.
Kennecott also reported that the Michigan Department of Natural Resources on December 6, 2007, recommended the State Natural Resources Commission approve two additional project authorizations—Kennecott’s plan for reclaiming the site once mining ends, and a land surface use lease agreement for the area where above-ground operations will take place.
Anglo American Taps Bechtel for Los Bronces Expansion (Latin America)
Bechtel Corp. announced on December 7 that it has been awarded an engineering, procurement and construction contract to execute Anglo American’s Los Bronces development project. Work on the $1.7 billion project started immediately following the announcement, according to Bechtel, and the project is scheduled to be completed in December 2010 with production commencing in January 2011. The project is expected to result in a mine life of more than 30 years.
The Los Bronces mine is located 65 km from Santiago, Chile, and the existing operations comprise a mine, a 58,000 metric tons per day (mt/d) copper concentrator, and two solvent extraction and electro-winning plants.
The Los Bronces development project will increase daily throughput by 87,000 mt/d by adding a new concentrator facility at Confluencia and Tórtolas II, both sites nearby the existing plant facilities. The scope of the new plant includes crushing and conveying, grinding and flotation circuits utilizing the largest proven equipment to maximize operating efficiency, plus concentrate regrind and a molybdenum plant.
Project management, engineering and procurement will be executed by Bechtel for 70% of the project and direct hire construction will be executed through a joint venture of Bechtel and Sigdo Koppers (BSK), which will provide the direct hire labor and supervision.
The Las Bronces development is the first stage in Anglo American’s pipeline of copper expansion projects which aims to increase copper production to approximately 1.7 million mt/y by 2016. In addition, Anglo American’s Base Metals division is currently progressing the $1.2-billion Barro Alto nickel project in Brazil which will also double total group nickel production by 2011.
Other Anglo American projects include Collahuasi (four potential projects: two debottlenecking and two sulphide leach, at an estimated total capital cost $3.2 billion); Quellaveco (potential production of 200,000 mt/y Cu over 26 year mine life, capital cost $1.7 billion, revised feasibility study under way, development decision expected in the second half of 2008; Michiquillay (company estimates five years to complete the feasibility study with production commencing 2015); Pebble (a 50:50 partnership with Northern Dynasty for a staged investment of $1.4 billion, potential production levels of more than 300,000 mt/y Cu and 500,000 oz/y Au, ramping up from 2015); Jacare (nickel, capital cost $1.2 billion or more, drilling is ongoing).
Major Wire Industries says that producers around the world are using its Flex-Mat 3 high-performance, self-cleaning screen media on all three screen decks to increase production of cleaner in-spec product and reduce costs. Major Wire offers a range of wire diameters and opening sizes to work on all three decks—up to 4 in. and as small as 30 mesh. Flex-Mat 3 is a non-woven, self-cleaning wire screen cloth that employs single wires running from hook to hook and bonded in place with lime green polyurethane strips aligned to each crown bar. The manufacturer says that because its wires vibrate independently, Flex-Mat 3 eliminates pegging on the top deck, and material passing through to the the middle deck will not blind, peg or clog the media. With more rock getting through to the bottom deck, fines will not build up, eliminating blinding. Flex-Mat 3 is claimed to have up to 30% more open area than woven wire, while its wear life exceeds that of traditional woven wire up to three times because there are no cross wires with high wear spots as there are with woven wire. www.majorwire.cc
This content is taken from the December 2008 Engineering & Mining Journal. Subscriptions are free to qualified recipients. Apply today for your free subscription.
