Technology Seeks Balance Between Higher Productivity and Environmental Benefits
Sustainability is a key word in political, academic and industrial vocabularies these days, though possibly with varying meanings. Nordic mining and mineral processing equipment and technology developers seek smart ways to help achieve it.
Recent studies in Sweden and Finland have highlighted possibilities for reducing operating costs and waste material generation before the blasting stage. For example, early in the project development process is exploration drilling as cost effective as it could be? Can core be assayed more rapidly to shorten the exploration time frame and reduce its environmental impact, especially where site access is seasonally restricted? How accurate is production bench drilling and can more detailed geometallurgical information help reduce ore dilution and waste loading, haulage and storage?
These questions were raised during just two meetings E&MJ enjoyed, one with the linked companies IMA Engineering Oy (IMA) and Mine On-Line Service Oy (MOLS) in Finland, the other with Wassara AB in Sweden.
Geometallurgy—The Essential Groundwork
At their offices in Espoo, Jukka Raatikainen, CEO of IMA, and Ilpo Auranen, CEO of Mine On-Line Service, talked about their efforts in the field of ore sampling and analysis.
Raatikainen has worked on the design, production and application of sampling systems and on-line analytical equipment, including X-Ray Fluorescence and Laser induced analysis systems, for about 20 years—with Outokumpu Technology before he established IMA. In 2006–2007, he started looking seriously at the possibilities for on-line analysis of the chips produced by reverse circulation (RC) and production blast hole drilling, an interest shared by at least one major drill rig manufacturer.
Auranen is a mining engineer with senior and international experience in drilling at Tamrock, then crushing, screening and mineral processing at Nordberg/Metso Minerals. Within his business development remit at Metso he paid attention to the better location of the ore minerals within defined mining blocks as a way to improve the value of the resource. In parallel, working with Pekka Pera on the Talvivaara project, Auranen also studied the financial impact of time lines on mining projects, especially the effects of exploration cycle times.
Their common interest in practicable solutions led to Raatikainen inviting Auranen to join the board of IMA Engineering and to collaborations that have created both a means to reduce exploration cycle times, especially for remote projects, and a system for on-rig sampling and on-line analysis of drilling chips.
MOLS develops
To address the delays and wasted drilling effort that the preparation and dispatch of core samples to a remote laboratory can lead to, IMA developed the XRF analysis and MOLS on-line results reporting system for use by the Mine On-Line Service company. The technology was tested at the Talvivaara and Kittilä projects. The resulting van-mounted Scanmobile geochemical laboratory and Remolog reporting service were described in the June 2009 issue of E&MJ (pp 44–46).
Updating that article, Auranen said a method for defining rock geotechnical quality as an RQD value has been added to the Remolog web-browser and also a mineral color analysis technique. One van has been able to cover demand in northern Sweden and Finland so far, with time at a specific site ranging from one week to a month and the analyzed core from 500 to 10,000 m. The Scanmobile can service up to 10 core drills. Approximately 60% of the work has been for grade control in existing mines while another significant application has been analyzing archived core at stores operated by the Swedish, Norwegian and Finnish Geological Surveys.
OreAlyzer onboard
The feasibility studies on which operational mine planning may be based usually include only ball park figures for ore dilution by waste rock during blasting. To compensate, many underground mines use expensive core drilling to establish ore/waste boundaries while surface mines working high value, low grade ores such as gold increasingly use reverse circulation sampling for grade control. In higher grade material typically the production blasthole drilling chips are sampled.
During 2008, New Boliden, unhappy with the results obtained from analyzing production drilling cuttings at Aitik, commissioned a sampling study. A comparison between cuttings sampling and meter-by-meter sampling of the whole length of the drill hole showed up significant disparities. For example, analysis of a cuttings sample might indicate an average copper content of 0.40% whereas the detailed sampling returned an average of 0.13%. That’s a substantial difference in metal value. The disparity seemingly results from the cuttings flushing process in which the cuttings produced from a significant portion of a blast hole are absorbed in voids so that the pile of chips at surface may only represent the very lowest part of the hole, including the sub-drill. The conclusion was the material must be analyzed during the drilling, independent of volume.
IMA’s solution was a tailor-made sampler-analyzer for either RC, percussive or rotary blast hole drills. Testing of the novel concept started in the Nordic region during 2007. The first prototype system, mounted on a trailer, was trialed with an Atlas Copco L8 rig working in both RC and DTH production drilling mode. The first on-board unit was fitted to a Bucyrus 49R rotary drilling rig in 2009 and a refined version has worked on a Pit Viper 351 rotary rig during 2010. MOLS developed a concept for charting the results for each hole and converting the data to a 3-D block model using kriging to achieve an accurate estimation of the ore values. Evidence suggests that ore dilution by waste rock can be cut from around 10% to perhaps 2.5%.
In March 2010, IMA Engineering signed a cooperation agreement with Atlas Copco Rock Drills AB to develop and market mineral analysis technology for use on Atlas Copco drilling equipment. The technology will be sold as an Atlas Copco brand, OreAlyzer, and the two companies exhibited the latest products on the Atlas Copco display at bauma 2010, including an OreAlyzer mounted on the Atlas Copco ROC D65.
Auranen and Raatikainen said the new tool will improve mine grade control and provide knowledge that can be used for more precise blasting and selective loading from the bench. Either through Atlas Copco or directly, IMA and MOLS can provide grade control consulting and technical services for mines on a global basis. MOLS has also developed a service for blast field 3-D mapping which is to be launched in the near future.
For standard RC and production drilling operations with either percussive or rotary drills, MOLS has introduced the Autosampler, a drill cuttings sampler with a packing device for conventional “bag-and-tag” samples. The Autosampler is suitable for both dry and wet cuttings sampling and can be easily fitted on any type of drill rig. MOLS says the unit combines the benefits of accurate sampling from a cone type divider with a rotating splitter and a remote controlled sample changer. The rig operator can take up to eight samples without changing the sample bags so sampling is accurate, the operator’s working environment is improved and more meters can be sampled per shift.
In IMA’s longer-established business areas the company continues to supply Innovative Mineral Analyzers for customers in the mining, construction, cement and industrial minerals industries. For on-line cross belt applications the company has developed the QuarCon XRF and OreSpex LIF and LIBS analyzers; IMACON XRF analyzers with sampling systems are for raw meal and slurry application; and the OreSpex analyzers can be configured for on-line truck and railway wagon load analyses. IMA also provides application studies, delivers systems and provides support—together with a network of local partners.
OreSpex has been tested at the Argyle diamond operation in Australia for distinguishing kimberlite and waste on feed conveyors and laser-induced fluorescence can also identify apatite on-line. However, the system is complex to use and site-specific, Raatikainen commented.
Deviations from Conventional Wisdom
Compounding any problem of value variation through a mining block, there is significant potential for inaccurate blast hole drilling that can lead either to leaving ore in place or to waste rock dilution. At the Wassara AB headquarters in Stockholm, Peter Johansson and Pål Jensen, respectively the company’s CEO and head of the Mining Business Area explained how the Wassara in-the-hole (DTH if you prefer) hammer drilling system helps solve this problem.
Although technical development to avoid deviation in top hammer drilling has had some success, not least in sub-level caving at LKAB’s Malmberget and Kiruna mines, the Swedish iron ore miner originally tested and in 1995 adopted the water-powered hammer as a more efficient tool for ITH drilling of long holes than the conventional air-powered drill, at that time and largely still regarded as the most accurate method of production drilling in hard rock mining. LKAB bought the technology from the developers and uses the water-powered system for all the ore production drilling at Malmberget and Kiruna. Wassara hammers have now drilled nearly 14 million mt in the two mines. The equipment is supported and serviced by a Wassara AB service team. Wassara AB is a wholly-owned LKAB subsidiary with a remit to market the Wassara system to the mining and construction industries.
The Wassara system’s greater effectiveness results from primarily from the much higher energy efficiency of water power, especially in underground mines where the air compressor may be a long way from the drill rig. A Wassara hammer has more power than an air hammer of the same size. In addition, all the energy in the supplied water is consumed by the hammer so the water flows out a velocity of 1–2 m/sec, enough to flush the drill cuttings but not to inflict damage on either the drill string or the hole wall. In sharp contrast, compressed air must expand on exit at high speed so the cuttings are highly energized. Consequently drill tube life is much longer with Wassara and redrills are less frequent. Other advantages include the flushing water being free of mineral oil and other potential pollutants, while it is also easy to remove the cuttings, and the water hammer being much quieter than a top hammer.
Wassara in practice
Primarily LKAB uses the Wassara system in sub-level caving. The accuracy of the ITH drilling has enabled the company to extend the vertical distance between the rows of drilling drifts to 28 m and to drill the central blast holes of each fan up to 53.8 m toward the drift directly above. This system reduced the number of drifts required by 70% from the 12-m vertical spacing used in the 1980s. Drilling with the Wassara takes approximately 33% less time per long hole than the top hammer rigs used previously.
Having been tested with AMV rigs the water powered hammer, drill string and pump system has been used mainly with purpose-designed Atlas Copco Simba W6 and Sandvik DL520-W rigs. The latter are equipped with a carousel that accommodates sufficient hammers to run on automatic overnight. The first hammer has a new bit, the second a once reground bit, the third a twice reground bit and so on to keep per bit drill meters as high as possible. A W6C rig with the Wassara string is also used to drill slot raises, which in most mines requires a specialized unit, Wassara points out. This system therefore offers significant potential savings for smaller mines with relatively few slots to drill. LKAB also uses Wassara for drilling service holes—for ventilation, drainage, cabling etc. Even when drilling 133- to 140-m-long holes at +60° angles deviation is only 1%-1.5%, so no redrilling is required. This replaces slow and costly diamond drilling.
LKAB has extensively checked the relative capabilities of top hammer and Wassara drilling in terms of accuracy. Measurements with Reflex instruments in production holes drilled at Kiruna showed that for up to 15 or 20 m the two drilled equally straight holes, but from there to 25 m the Wassara stayed on course but the top hammer started to deviate. Beyond 25 m the Wassara also started to deviate but to a limited extent and less than the top hammer.
Though less efficient or environmentally friendly, air-powered ITH remains an option. However, a comparison between air-powered ITH and the Wassara system at a geothermal energy project, where bore hole accuracy is essential, yielded surprising results. Deviation with Wassara averaged 1.3% but with the air-powered hammer it was nearly 20%. In addition the air ITH rig could not drill deeper than 180 m at which point the rock had a higher water content—this is not a problem for the Wassara system. The company claims that the full system, used with a good rig in any normal geological conditions, can drill any length of hole up to 250 m and more with 1%–2% deviation.
This accuracy results largely from the stability of the drill string and the hole wall. The hammer has stabilizing ribs along the 1.4-m length of its casing, such that there is typically only a 1- to 2-mm gap between the stabilizer rib and the hole wall. The hammer can also be used with a separate stabilizer tube immediately behind it, the two together being the same length as the 1.6- to 1.8-m-long drill tube sections that follow. For horizontal or inclined drilling, stabilized tubes can be added to restrict deviation, creating the X-Straight Drilling System.
Wassara supplies the system’s whole drill string and the water pumps. The company presently manufactures a range of six hammers from the W50 for bit diameters 60-64 mm through to the W200 for bits up to 254-mm-diameter at premises near Stockholm, employing 11 people. A smaller hammer is under development. The Wassara check valve is available for use in conditions where there is a risk of particles entering the hammer from the drill bit side when the hammer is shut off. The stabilizers and tubes are made to precise Wassara specifications elsewhere in Sweden. Water swivels are available for simple adaptation of drill rigs to run the Wassara system. WASP high pressure water pumps can be matched to the hammer sizes and supplied with either diesel engine or electric motor, sound proofed if required.
The bits are also manufactured by third parties and are basically redesigned air-ITH bits but with more steel and smaller flushing holes. Jensen said these may not always be optimal so Wassara is developing a purpose-designed bit with more than one manufacturer. Alternatively the company might make the bits in house.
Leading the horse to water
The clear message, said Wassara, is the greater accuracy of water-powered drilling gives greater control of the drill pattern, so only the necessary hole meters are drilled, not with a safety margin—which can be up to 30% extra drilling at some operations. The results are: lower costs, optimum fragmentation, optimal operational scale, and a consistent quality of feed to the process plant—which also lowers operating costs.
Acceptance in the mining market has been relatively limited despite the success at LKAB. Partly, according to Johansson and Jensen, this is because mining applications require the series manufacture and support of specialized drilling rigs whereas for construction a wide range of rigs can be set up with special power packs. The W series rigs that potential customers saw at LKAB were not available for sale until quite recently and while Sandvik agreed to take on marketing the Wassara system to the worldwide mining industry in 1996 the regional sales teams were not familiar with the technology. The Canadian company Cubex has built a number of rigs for Wassara over the past 10 years, four of them for mining applications.
Currently, the Wassara system is in regular use at Codelco Chile’s Andina mine and from time to time at El Teniente as well. In Canada, Cameco is using Wassara at the McArthur River uranium mine, in South Africa Anglo Platinum and Harmony Gold at Target are using the technology and in Zambia it has been deployed at Chibuluma. In Europe, the Mittersill tungsten mine in Austria has used Wassara and in Australia Swick Mining Services has adapted a rig to use the system in order to demonstrate the concept.
In 2007, Wassara took over responsibility for the mining market. Johansson and Jensen believe mining company corporate managements are looking to re-engineer their operations to a major extent in the search for sustainability. Wassara’s approach is to try to convince these executives the Wassara technology is a valuable option for such exercises so they will pass this message to operational managers. Meanwhile, Wassara is adding more potential mining applications to the mix. New systems are being tested and will be introduced as soon as they are approved.
Aces in the Hole
Of course, not all deviation is bad news. Controlled deviation is an important tool in exploration drilling and geotechnical surveying and Nordic companies such as Devico are leading exponents, although Reflex Instruments AB has moved to Australia.
Another specialist in down-hole survey systems is Stockholm Precision Tools AB (SPT) which was recently happy to publicize the role of one of the company’s customers—GeoAtacama Consultores Ltda—in helping to navigate the hole that located the 33 miners trapped in Chile’s San Jose mine on August 22. The north-seeking gyroscope was able to determine the real azimuth for the borehole drilled to the miners nearly 700 m below surface. “Had it not been for the exceptional precision of SPT equipment, it would have been impossible to find the trapped miners,” said GeoAtacama manager Felipe Matthews Rojas.
Based in Sollentuna, near Stockholm, SPT designs, develops and engineers advanced, rugged, reliable and accurate down-hole survey systems for the oil and gas, and mining industries worldwide. These wireline and memory down-hole navigation systems, including gyro and magnetic deviation tools, have been developed to cope with the greater drilling depths and more complex trajectories required today.
SPT also offers logging systems with wireline and memory mode and a measure-while-drilling option, as well as on-site calibration tools to ensure ongoing accuracy at the work site. The company also undertakes down-hole deviation surveys, has a team of skilled field support engineers, and provides training courses. To meet tomorrow’s needs the company continues research and development.
Specific products include the GyroTracer borehole deviation survey tool, a 42-mm-diameter north-seeking gyro tool designed for highly accurate deviation surveys in magnetically disturbed environments. It can be configured with a surface control box for real time data acquisition or with a battery-powered memory module option so it can be used without conductor wireline and accessory gear. This latter system can save up to 70% of direct costs, SPT says. The company also offers various accessory tools for the control of directional drilling.
One exploration drilling contractor and rig builder that has invested in Stockholm Precision Tools technology for hole deviation surveys is the Finnish company Oy Kati AB. Before purchasing, the Kalajoki-based company visited SPT to check that the north-seeking GyroTracer is, as claimed, the fastest, most reliable and accurate instrument of its kind currently in use, and also that it met specific technical and environmental standards.
Business Manager Matti Rautakoski said Kati is happy to offer surveys to mining companies, contractors and even companies outside the mining sector who need accurate hole deviation surveys. According to SPT the GyroTracer is also a good option to help with wedging or steering the holes.
Kati has also started drilling deep holes at the Kittila mine with its latest drill rig model, the Deep Drill Pioneer 150–DDP 150. Equipped with the very first Sandvik DE 150 exploration drill the new rig is capable of drilling to a depth of 2,000 m with the NQ size and is the most powerful rig in the Kati range. This rig is transported by crawler carrier and lowered to ground level for drilling. The cab is of a very ergonomic design for greater operator comfort, efficiency and safety and has controls in the seat arms. “Since this is a very different rig from our previous models the design and manufacturing process was anything but straightforward. However the DDP will take comfort, safety and performance to a new level in Scandinavian markets,” said Rautakoski.
Meanwhile Devico AS has ongoing mineral exploration directional drilling projects for Agnico Eagle at Kittilä and Lundin Mining at Castro Verde in Portugal. At Tennant Creek in central Australia the Norwegian firm has recently completed a mineral exploration job for Westgold. And in Brazil, Devico is working with the local drilling contractor Servitech at the Crixac and Caiamar projects.
They Know the Drill, and More
For some time now, both Atlas Copco CMT and Sandvik Mining & Construction (SMC), the two major Nordic mining equipment manufacturers locally referred to as the Dragons, have been expanding their product ranges within and from drilling equipment. As well as exploration, mining and tunneling drilling rigs and tools, both offer underground haulage equipment. Sandvik has also invested in the production of underground coal mining equipment, crushing and screening systems, and bulk materials handling technology; Atlas Copco has acquired the Dynapac road machinery business. Sandvik Mining & Construction has around 14,400 employees and Atlas Copco Construction and Mining Technique about 8,000.
Although both firms found it necessary to improve process efficiency and reduce costs in 2009 each has very recently announced new investment in crushing and screening equipment production. On the product development front Atlas Copco has followed the launch of the SmartROC D65 for surface operations with a new small drilling rig for narrow vein mining. And Sandvik has just announced it will deliver loading and haulage automation technology and load-haul-dump vehicles to New Boliden’s Garpenberg mine in central Sweden.
Investments in Crushing
In Austria, Atlas Copco Austria GmbH has acquired Hartl Anlagenbau GmbH, a well-established manufacturer and supplier of mobile crushers and screeners. The unit will be known as Atlas Copco Powercrusher and Dominik Hartl is the sales director. Sandvik is expanding its crushing equipment manufacturing plant at Svedala in Sweden having already decided to build a new distribution center there to supply spare parts to the European market.
Vice President Marketing Bo-Göran Johansson said the Powercrusher range covers jaw crushers, impact crushers and cone crushers with capacities ranging from 200–500 mt/h, and screeners with capacities of 200–400 mt/h. The Powercrusher products are mainly distributed through a dealer network and the majority of the sales have been in the United States, Russia and western Europe. “By implementing Atlas Copco Powercrusher products into the already existing world-wide network for sales and support within Atlas Copco, we increase the possibility to serve the market with our products,” said Hartl.
Sandvik will invest SEK300 million in a new production plant at the Svedala operation which includes the company’s product development center for crushing technology. The near 6,000 m2 new facility will manufacture key components for Sandvik’s crushers that will be used at the assembly plant in Svedala as well as at those in other countries. The state-of-the-art plant should be completed during early 2012, Sandvik said.
Born again Boomer
Early in the 1990s, Atlas Copco had one of the first Boomer 104 rigs stop over at the World Mining Equipment Narrow Vein Mining Conference in Salt Lake City, Utah, USA, on its way to a customer. The small and flexible face drilling rig has been a success in small mines ever since. Now the Face Drilling team at Atlas Copco has launched its successor, the Boomer T1 D.
Naturally the new machine retains the basic design and capabilities of the Boomer 104 but it also features numerous additions and upgrades to improve productivity, safety and operator comfort. The new carrier frame is stronger than its predecessor and has a lower center of gravity as well as an oversized articulation to cope with particularly demanding operating conditions. There is a more powerful Tier 3 engine providing higher tramming speed and less polluting exhaust. The boom suspension system exerts less stress on the machine and improves operator comfort when the machine is in motion and serviceability has been improved by making the service points more accessible. And an ergonomic and comfortable cabin with better visibility is one of the optional extras.
Like the ST7 loader described in the March issue of E&MJ, the first Boomer T1 D was tested at the Lovisa lead-zinc mine in Sweden where the Boomer 104 had been in use. Atlas Copco said the operators liked the improved ergonomics and drilling performance they could achieve during the trial. “We know our customers liked the Boomer 104 for its flexibility and small size but we think people will fall in love when they see the Boomer T1 D,” said Peter Bray, Atlas Copco’s product manager for face drilling equipment.
Material Dynamics
While mining has historically been the basis for a significant part of industrial production in the Nordic region, the materials producing sector has reciprocally been closely involved with the manufacture of mining and processing equipment. In particular special steels making has been linked with hard metals production and the manufacture of tools, including rock drilling tools. Abrasion-resistant steel plate is used regionally and internationally for wear-resistant components of mining and mineral processing systems, and foundry operations make wear products for crushing equipment. Wear-resistant plastics products developed in the region are also making a growing contribution to fluids handling in the mineral industry.
Robit: Rock Tools on a Roll
As a result of profound changes in the economic geography of hard metals production during the past 30 years there is no integrated ore to rock tool manufacturing in the Nordic region now. But Sandvik still combines steel and cemented carbide production ahead of its rock tools manufacturing operations and in Fagersta Atlas Copco Secoroc still makes cemented carbide inserts for its rock tools range.
In Finland, Robit Rocktools Ltd. (Robit), which is celebrating its 25th anniversary in 2010, produces neither cemented carbide nor steel and employs about 40 people. The company buys cemented carbide buttons made to its specification from manufacturers in Britain and the United States. And it very carefully treats bit bodies made of Finnish steel.
Utilizing End-User Experience
In the company office and factory at Vikkiiniityntie 9, Lempäälä—just south of Tampere—CEO Jussi Rautianen and Mikko Mattila, vice president sales and marketing, said in their view Robit has been able to compete with the larger drilling equipment groups in this segment of the market because of Robit’s specialized focus. Since the company was formed in 1985 by three former Tamrock drilling specialists Robit has focused on drilling consumables designed to penetrate the most challenging rock types, initially for blasting in mines and quarries, since 2000 for ground engineering, water and thermal well drilling with casing systems as well. From the start the design and manufacturing engineers have sought to utilize the experience of end-users to develop the products. This knowledge through partnership, combined with the best available materials and a high precision manufacturing process, has enabled Robit to design and supply superior products.
Some 50% of the company’s turnover comes from top hammer tools and half of this comes from mining, Mattila explained. Consequently Robit has concentrated on two targets. The first is delivering quality: defined in terms of drill meters per bit lifetime; drilling penetration rate which, he said, can vary by up to 20% depending on bit quality; and hole straightness, which is particularly influenced by the bit’s drop center design. The second is attentive service.
Diverse Markets
Apart from the period immediately after the company started in business by supplying Finnish customers, Robit has been heavily export oriented, typically selling 90% of production to customers via distributors in more than 60 countries. Sweden, which was the firm’s first foreign target followed by Norway and Germany, is now the main export market, with Russia—where there is a subsidiary sales office in Moscow—second. Canada and Chile, where Robit has had contracts with Codelco for the El Teniente and Andina mines for nearly 10 years, are also major markets and the company has been rather successful in southern, central, eastern and west Africa.
The recent development of new mines in Finland has presented opportunities for Robit and the company has been able to gain a leading 35% share in what is now an €10-million market and likely to grow. This has reduced the export sales percentage to 80%–85%, said Mattila. Finnish customers include Agnico Eagle’s Kittilä mine, Inmet Mining at Pyhäsalmi, Outokumpu Chromite’s Kemi, Polar Mining at nearby Orivesi and Talvivaara Mining. Polar Mining sends boxes of bits to the Robit factory for regrinding while at Talvivaara the company has provided an on-site technician and a grinding service for the bits used on the mine’s Sandvik drilling fleet on a two-year contract with an option for a third year. Robit will look to offer a similar service in other markets, possibly offering to cover the bit regrinds, which average 5-6 per bit, as part of the non-discounted bit price. At both the factory and Talvivaara Robit uses CME regrind machines.
Stepping to the Next Level
E&MJ asked Rautiainen and Mattila how Robit had fared during the recent sharp recession. They replied the company had utilized the period of reduced demand to continue the modernization of the premises.
Taking advantage of the downward trend in the prices of complex machine tools the company installed a 5-axis CNC unit which enabled the production of more advanced drill bit body designs. The extended factory was up and running in the spring 2010 giving the company possibilities for higher production rates and also for more efficient manufacturing processes.
Another positive facet of the financial crisis was the opportunity to recruit three good sales people—one South African, one Russian and one Finn—which has helped Robit achieve a rapid recovery this year. Management projects sales in 2010 to be at a higher level than in 2008.
Green Steel
The expansion program also helped Robit to launch a completely new button bit series called HTG at bauma in April. These bits feature SuperDome buttons inserted in a new face and body design. This combination delivers faster penetration, improved flushing and straighter holes through better flushing.
Robit further optimizes bit body quality by heat treating the machined steel parts in an aluminum oxide fluidized bed which achieves very consistent quality. This process is much easier to control than conventional heat treatment, Mattila said, and no sand blasting of the bodies is required afterwards. In addition there are no emissions from the process which is carried out in clean-room conditions. Robit has proved the quality of its products and processes among its customers worldwide. To maintain this position the company has upgraded the quality system to meet the ISO9001:2008 standard. The certificate was granted by DNV on April 22, 2010.
To further improve production capabilities Robit will soon install a new drilling machine, a new automatic button bit insertion machine and an automated painting line.
Product Lines
Robit offers a comprehensive range of HTG Series Green Steel button bits for construction, quarrying, mining and tunneling drill and blast applications, with R25, R28, R32 and R35 threads variously covering the bit diameter range 33–76 mm and with normal and retrac bodies. Reaming equipment includes pilot adapters, chisels, reamers and dome reamers. For bench and production drilling there are C38, 45, 51 and 58 threads plus RG60 and CT68, variously covering the bit diameter range 55–152 mm. These are matched by button bit adapters, rods, couplings, shanks and Sandrive and Wingdrive grinding cups for round and ballistic buttons.
Casing systems are the key components of the Ground Drilling Tools range which covers: forepoling, anchoring, piling, water and thermal well drilling, horizontal drilling and underwater drilling. RoX and DTH-RoX products are the key components of the product line. Although the casing systems business is largely separate from the mining side, forepoling does sometimes find application for short-term support during mine development in soft or unconsolidated ground.
In addition, Robit has a partnership deal with Mincon, based at Shannon, Ireland. Mincon manufactures DTH hammers and bits that Robit sells in Russia and the Baltic States while Mincon sells Robit casing systems in Ireland, the UK, South Africa and the U.S.
Rautiainen and Mattila concluded with the comment that investment has allowed Robit to gear up for growth with more space and a more efficient operation. The company is optimistic about its future. SSAB Drives a Hardox Bargain Since Svenskt Stål AB (SSAB) was created in 1978 it has evolved into a leading supplier of high strength steels. The change has been good for the company. Sales grew from SEK4,174 million (current exchange rate 1 SEK = 0.15 US$) in 1979 to SEK15,972 million 10 years later and profit after financial items from—SEK410 million in 1979 to SEK1,579 million over the same period. From SEK16,807 million in 1999, sales had risen to SEK54,329 million by 2008, when profit after financial items was SEK8,953 million. The changing product mix has also been good for customers as high strength steels can improve product performance and durability and at the same time reduce adverse environmental impacts. It is not too surprising that by 2009 some 32% of SSAB’s total deliveries were niche steels the company aims to increase this proportion to 50% in 2015. Among the high strength steel brands which SSAB markets, the market leading Hardox is extensively used in mining and mineral processing equipment.
This strong position in special steels has not been achieved easily. It is the result of a series of strategic plans, the realization of which has required tough decisions.
As a whole SSAB’s niche product strategy is to make value-added steel for particular applications with +400-MPa yield strength, while Oxelösund’s niche plate products start at 700 MPa.
Material development and marketing
At SSAB headquarters in the World Trade Center building above Stockholm’s central railway station, Karl-Gustav Ramström, SSAB’s executive vice president of market and sales, and Claes Löwgren, senior project leader, business development, explained the approach that has helped SSAB achieve its leading position in the supply of high strength steels to the mining and mineral processing industry. The key has been focusing on the end-use customer.
Trends within the Swedish steel sector encouraged SSAB Oxelösund to work more closely with customers on product development, to recruit applications-oriented engineers and to create an appropriate organization with technical development facilities. In line with customer preference, high strength abrasion-resistant steel development looked not only at the hardness characteristic but also at workability through other properties, said Ramström. “For Hardox customers it’s not what’s on the data sheet that matters most but the workshop properties,” said Löwgren who is an applications engineer focused on wear issues and material development projects and has practical mining experience. Also necessary to provide better customer support was an in-house design capability.
Although Oxelösund was not the first mill to produce hard grades of quenched steel it was the first to combine hardness with weldability and bendability. The first abrasion resistant materials, produced in 1973-74, were OX AR 320, 360 and 450. The first bendable abrasion resistant plate, OX AR, rated 400 HB was produced in 1978. Some years later SSAB introduced the bendable OX AR 450 with 500 HB. In 1984 these were branded HARDOX 400 and 500 respectively. However, Chilean customers wanted an even higher rating and the Oxelösund team responded with Hardox 600HB. Hardox 450, now the most widely used grade, was introduced in 1998 and Hardox Hi-Tuf was launched in 2001 to meet demand for greater toughness from yellow goods manufacturers. It has also been used to solve bucket performance issues on the Bucyrus RH 400 excavator. Hardox 550, which followed in 2004, was designed for uses such as the rear-end member of dump truck bodies. Hardox Extreme, a very hard plate suitable only for small parts on account of its internal stresses, was made available in 2006. This grade may well compete technically with hard facing materials in some applications and be more cost efficient, Löwgren suggested.
SSAB has now worked closely with customers for 25 years on maintenance issues as well as with OEMs. The company has learned a lot from what is usually a symbiotic relationship, finding it is sometimes easier to take risks at the cutting edge of technology with a single end-user than with an OEM. Since first working on the use of Hardox 400 for the structural repair of vibrating screens with a German partner and wear part specialist, Bergauer Rege, SSAB has built on such customer relationships to create an international Hardox wear parts partner system involving independent customers and distributors as well as SSAB in-house service workshops in Canada, South Africa, Portugal, Singapore and China. The network has about 100 members.
An example of how this system can work is reported by the Austrian components manufacturer Winkelbauer Maschinenbau, a Hardox Wearparts company for many years. The company received an order from Sandvik Mining & Construction to deliver 350 mt of Hardox 500, in the form of 4,383 items and 550 different parts, to a crushing plant 70 km north of the Arctic Circle in Sweden starting within just four months. In addition, the perfectly welded parts would have to be meticulously inspected and documented as fulfilling the strict quality criteria set by Sandvik and the final customer. ”If we had not been a Wearparts network member, we would have had no chance of getting this quantity of Hardox,” said General Manager Michael Winkelbauer. “This project started in the midst of the economic recession when large quatities were hard to come by. We were the only supplier that could meet Sandvik’s tight time and quality requirements.” Within five months Winkelbauer had successfully delivered all 316 pallets of parts, on time and on spec, without a single reject.
Also working with customers, just over 200 in fact said Ramström, SSAB has created the brand program “Hardox in my body” which jointly profiles quality products manufactured using top-grade materials.
Technical customer services
Systematic evaluation of wear conditions can enable many mines to improve productivity, in terms of cost per mt ore produced, by using Hardox wear plate. Much of the work done is not exactly glamorous but it can yield significant savings. To assess a potential or existing customer’s needs, SSAB’s technical teams take rock and mineral samples and make an inventory of the materials presently in use on the job site in order to present a Wear Analysis Report. The studies undertaken in the preparation of these reports often make use of the software suite WearCalc and other general engineering estimation tools that SSAB’s Wear Technology Group has developed in the course of mining-related wear and wear design estimation involving structured field tests and laboratory work.
The Wear Technology Group can also assist in evaluating the “abrasivity” of different rocks and ores and further participate in a discussion to find the best wear resistant solution for a particular component. SSAB makes a distinction between Active and Passive Components. Active components are engaged in “high energy contacts,” mainly in rock deterioration processes, while passive components merely protect a sub-structure from the rocks so they are subjected to low energy contacts. This division has some influence on evaluations of different wear resistant materials.
WearCalc will calculate the Relative Wear rates of different HARDOX grades subjected to either sliding or impact abrasion. Evaluation requires an initial petrographic examination of the rocks have to be done. Once the mineral volume content is revealed the Relative Wear Rates, or more often the Relative Service Life values, of the different steel grads subjected to that specific rock can be quantitatively compared. Using the WearCalc approach will make field testing more efficient by reducing the number of steel grades needed for a more general estimation. The current version is WearCalc 2.
To assist application development, SSAB has also compiled a design manual for Hardox and the extra high strength structural steel Weldox. Drawing on supplier and customer experience the manual points out the difficulties as well as the advantages of using the materials, which is much appreciated by customers, said Ramström. Another tool on offer is FEM simulation in general and especially the Drop Weight Test simulation, used to predict denting and cracking. All of these techniques for materials selection are continually upgraded.
Collaborative design exercises
Some 15 years ago, when SSAB was developing HARDOX 450, the company worked on the design of bodies with the German tipper truck manufacturer Carnehl. SSAB suggested a free-hanging concept which Carnehl adopted, designing a tipper body that could absorb heavy impact even though the structure was both free-hanging and slender. The idea was that by utilizing more plate material for energy absorption the local strain would be distributed to a larger volume of plate and so the plate response would be mainly elastic. To perform this way the plate would need a combination of sufficient strength and toughness and that is where Hardox 450 came in. The tipper body performed very well technically and became a commercial success for Carnehl. More recently an SSAB technical team convinced the Chinese company Longmei Engineering it would be worth changing from the conventional truck bodies Longmei was using to haul waste at the Xiaolongtan coal mine in Yunnan province to a U-shaped body made with Hardox 450, which was 1.1-mt lighter. Longmei reported that it takes only six months to recover the investment in Hardox.
In 2007, SSAB’s Conceptual Design Service and the Wear Technology Group decided to apply similar thinking to a body design for articulated dump trucks. The project was undertaken with a construction sector customer. The design of this type of truck has a somewhat different set of geometrical conditions from a road tipper, explained Löwgren. The target for the project was to reduce the weight while maintaining the length of service life. SSAB wanted to estimate the potential improvement in capacity and evaluate the inherent value of such a body. The project team was able to reduce the weight of a 35-mt-capacity truck by 3.5 mt and has tested the structure at a road building site where varying sizes of freshly blasted granite were being transported. Manufactured using Hardox 450, the truck was displayed at Intermat in April 2009. SSAB believes using the new design will enable manufacturers to reduce vehicle production time through more cost effective production processes but will mainly they will be able to create a lighter body with more payload.
Other examples of potential and actual problem solving with Hardox involving interventions to improve existing equipment include: identifying changes of the wear plate material used on the dump bodies of 240 st mining trucks in Canada to increase payload; replacing AR 500 steel used on a transport chute at a platinum mine in South Africa with Hardox 550 to achieve a 2.6 times increase in life; determining the suitability of Hardox 600 for lining chutes at at other platinum mines in South Africa; and determining the most appropriate mix of Hardox grades for optimizing the life of excavator buckets for mine customers in Chile.
Enhanced customer and environmental focus
SSAB continues to invest in R&D to improve both the high strength steels product range and the production processes it employs, spending almost SEK200 million in 2009. A new strategic research center for the whole group is being established and during 2009 SSAB became a core member of the European ULCOS project aimed at developing production methods that emit less CO2 than even the best present technologies.
Hardox could not fully protect SSAB from the sharp downturn in the world steel market in 2009. Compared with figures of SEK17,991 million, 13,237 million and 16,745 million, respectively, in 2008, strip, plate and U.S. sales fell to SEK10,001 million, 7,634 million and 8,799 million in 2009.
Even so, SSAB calculates that the approximately 1 million mt of steel niche products it sold were equivalent to 1.45 million mt of ordinary steel, reducing CO2 emissions by 0.89 million mt. The calculation is based on high strength steel having a yield point twice as high as that of the ordinary steel so reducing the weight by approximately 30%.
One of SSAB’s responses to the weaker marketplace was to introduce a new organization with effect from January 2010, replacing the previous Plate, Strip Products and North America divisions with three geographic business areas—SSAB EMEA covering Europe, the Middle East and Africa; SSAB Americas responsible for the North and South American markets; and SSAB APAC which covers Asia and Australasia.
In any case, the market has improved so far in 2010 though the rate may be slowing in the second half of the year.
Multilayer Solutions can Save Millions in Maintenance
Whether you want a mine tailings line in Indonesia, bioheapleaching pipes in Finland or raw water pipelines in North America, there is a good chance that KWH Pipe has already done it, says the Vaasa, Finland-based company. With an expanded range of products and experience that is extending geographically and in terms of application range, the company believes it can offer solutions where other pipe manufacturers lack the right product, knowledge about its performance or installation capabilities. “That’s why we call ourselves pipe systems provider, rather than a pipe manufacturer,” said Stefan Gros, executive vice president of product and production development.
“For a pipe systems provider like KWH Pipe, the interaction with industrial customers is very rewarding. Sometimes they ask us to come up with new ways to fix their problems, in other circumstances we will approach customers with a new product. At first they might claim that their current product works just fine, but when we start asking questions about downtime, maintenance and installation, and explain how our solution works, it makes them think. Once they start analyzing the costs, they realize just how much money KWH Pipe can save them,” said Gros.
During the last few years, KWH Pipe has worked on developing its range of Functional Piping Solutions (FPS). These products all have some things in common: a multilayer structure, a narrow focus on solving a particular problem and the possibility of customization to provide a solution especially for the conditions of a specific project. “We have researched which polymers are especially resistant to, for example, abrasion or certain chemicals,” said Gros. “Sometimes it’s possible to produce a pipe entirely from those materials, but as these are specialty polymers it would be very costly. Therefore, in our FPS products, most of the pipe wall is made up of polyethylene, and the functional polymer layer is only as thick as it needs to be. The polyethylene gives the pipe structural strength, flexibility, light weight and corrosion resistance and manufacture is cost-efficient.”
WehoSlurry is a complete system for transportation of abrasive sludge, slurry and dry materials. This highly wear-resistant piping system can be used, for example, in the mining industry, as feed lines for fish farms, or in the paper and pulp industry. In these applications and many others, the medium transported in the pipe contains particles so hard and sharp that they quickly erode most types of pipes from the inside out. The downtime needed to replace the pipes can have a significant negative impact on the bottom line of an industrial operation. Therefore, a piping system that has a significantly longer service life has been desired by many maintenance engineers worldwide.
Sometimes, metal pipes are claimed to be abrasion-resistant, since they are produced from a harder material than the abrasive particles to be transported. However, a hard material like metal is also brittle, and even though the pipe would withstand the wear from the inside, it might be too brittle to handle stress from pressure surges or ground movements and would consequently break. The WehoSlurry pipe is designed to absorb this type of stress and offer optimal durability by combining the flexibility and corrosion resistance of polyethylene with an extremely wear-resistant inner layer. Also, instead of being hard, the inner polymer layer provided is soft because abrasion tests in laboratory and also full-scale tests clearly indicate that softer materials wear less in most cases. This is how KWH Pipe can prolong the life span of a piping system using functional polymer layers.
WehoChem is a piping system especially developed for transportation of highly aggressive process chemicals and has proved itself by transporting 93% sulphuric acid for a processing plant. The polyethylene pipe is equipped with an inner layer that is customized for the chemicals to be transported. In comparison with PVDF or acid-proof steel pipes, it is a very cost-efficient alternative. Handling is facilitated by the pipe’s light weight, and installation is quick and simple as smaller dimensions are delivered in long lengths on pipe reels. Storage tanks can also be equipped with specific chemical-resistant properties.
WehoAntistatic is an electrically conductive pipe system for conveying flammable substances in gaseous, liquid or solid form. Examples of such substances are industrial effluent containing landfill gas, industrial raw materials, dust, flour and wooden pellets. Metal pipes have traditionally been used for the purpose, but they are prone to corrosion so WehoAntistatic offers industrial customers an interesting alternative. There are also tanks utilizing multilayer technology for storage of the same type of materials.
Process Practice Makes Perfect
Well not quite yet, experience at Kittilä, Sydvaranger and Talvivaara would seem to confirm. But developers and suppliers of rock and mineral processing equipment do cover many of the bases and many of them can apply a wealth of operational and academic expertise to the optimization of process routes from blasting through to load out. The Finland-based global process technology companies Outotec and Metso Minerals are cases in point.
More Out of Outotec
Sustainable use of natural resources is Outotec’s mission. The company characterizes itself as a worldwide technology leader providing innovative and environmentally sound plants, processes, equipment and services for customers in minerals and metals processing as well as related process industries. At the company’s offices on the “Outo Campus” in Espoo, Vice President of Corporate Communications Eila Paatela and Timo Nore of marketing communications said approximately 80% of the company’s deliveries at this time are environmental goods and services as defined by the OECD.
Outotec also pursues a business strategy of growth through innovation, addition of complementary technologies, and development of its service operations. At first glance the company’s announcements covering the period since our report last October suggest a development mixture as before:
- In the improving market of first half (H1) 2010 Outotec spent €13.7 million on research and technology development, representing 3.3% of sales—not surprisingly a higher proportion than in H1, 2009. The company filed 32 new priority patent applications and was granted 81 new national patents, and delivery commenced of the Enefit technology developed for Eesti Energia’s oil shale plant at Narva, Estonia.
- Outotec sees India as a growth market and in December 2009 inaugurated a subsidiary in Kolkata, India. “We have established customer relationships in India and the new local operation in Kolkata improves our cooperation with Indian mining and metals companies. Now the entire Outotec technology and service offering is easily available to our customers,” said Pertti Korhonen, Outotec’s CEO.
- In 2010, the company completed the acquisitions of Ausmelt in Australia, Larox in Finland and elsewhere, Edmeston and Millteam in Sweden, thereby expanding its offering to include, respectively: Top Submerged Lance smelting of various concentrates, residues, other secondary and also waste materials to recover valuable metals; a wide range of filtration equipment including the ceramic filter previously developed by Outokumpu; stainless steel equipment for sulphuric acid production; and grinding mill and other services.
- The first half 2010 order intake of €769.1 million was more than triple that in H1, 2009. Sales of services during this period increased by 53% to €112.5 million and represented 27% of Outotec’s first half sales, compared to 16% in January through June 2009. This growth was mainly due to the new business acquisitions. Outotec received six major orders in the first quarter of 2010, including two from India and two from China, and four in the second. The technology involved includes copper and nickel grinding, flotation, SX-EW, roasting and smelting; sintering systems for chromite, iron ore and manganese; iron ore pelletization and Kaldo furnaces for gold recovery. In Finland, as well as assisting with the ramp-up at Talvivaara Mining, Outotec is to supply 68 flotation cells to the Kevitsa project as part of an €20 million deal with the First Quantum Minerals Projects Office based in Perth, Australia, for the delivery of flotation, thickening and automation technologies to several of their operations around the world. This flotation technology delivery complements the earlier agreed supply of Outotec grinding mills for Kevitsa. There is much more but Outotec only announces deals involving more than €10 million so that some contributions from the new acquisitions may not be immediately apparent, though they are very real.
- At least three major deals have been announced in the third quarter at the time of writing, including orders for an iron ore sinter plant for the Steel Authority of India Ltd’s Bhilai plant, a flash smelter and associated services for direct to blister smelting at Konkola Copper Mines’ Chingola smelter in Zambia valued at €13 million, and technology for Australia’s Karara Iron Ore Project worth more than €28 million. Outotec’s solution for Karara includes design, supply, delivery and installation of the complete flotation circuit along with all filtration technology for the project. This project demonstrates the excellent fit of the Larox filtration technologies to Outotec’s technology portfolio. Now we can offer larger solutions for our customers and use efficiently our global resources in sales, project delivery and services, says Outotec.
