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By B. Cousins

Flotation reagents are critical to the optimum performance of flotation circuits. How a flotation reagent performs within the first few cells of a flotation train is a key indicator of how well it will perform throughout the entire circuit. A method to compare reagent performance was recently developed by Ashland Water Technologies. The procedure involves collecting a timed sample of concentrate from each cell and then measuring the volume of the settled solids. An estimate of the percentage of concentrate collected from each cell can then be mathematically determined, providing an understanding of the recovery changes in each cell. Data from trials at a coal flotation circuit are used to demonstrate the method's validity.

Feb 27, 2013

By Kevin Phelps, Jason Baird, Philip Mulligan, Dominique Nolan

Determining the transitions from run-up to optimal cut length and optimal cut length to run down, without bias, from the penetration of a linear shaped charge (LSC) is difficult. The stresses applied to the targets during explosive testing can distort the targets in such a manner that determining the true distance of cut, penetration, or fracture can be demanding. Through the course of this research, it was observed that the researchers made many of the errors involved in the collection of data. Among these errors researchers found problems in: determining and fitting the sample to a single plane from which to read measurements, determining where along the path of cut the three phases of penetration transition, and the precision of measurement based on handheld tools and the human eye. This study looks at three methods of recording the data of a series of linear shaped charge tests. The tests resulted in samples which are not ideal for measuring with common laboratory devices like measuring tapes, calipers, or rulers. The first method utilized these common laboratory devices and the difficulties the authors experienced are described in this paper. The second and third methods involve digital photography, image manipulation, and the use of AutoCAD. Methods two and three are then compared to the simple observational method and discussion is made in regards to the precision and accuracy of each method.

Jan 1, 2013

By Mats Keisu, Bengt Niklasson

The Sofia project has increased the level of knowledge and technique within tunnelling, drifting and contour blasting.

Jan 1, 1992

By H Han, W Wang, E Zhou, D Duan

"In this study, physical, chemical and microscopic characteristics of high phosphorus oolitic hematite were studied firstly. Based on which, the new methods of high phosphorus hematite used in the æsolid state reduction by rotary hearth furnace - magnetic separationÆ and iron nugget by rotary hearth furnace direct reduction processes were discussed. The results showed that high temperature, low basicity and high carbon content is conducive for the apatite in iron ore to reduce into molten iron, but not conducive to the removal of phosphorus. Through optimisation of process parameters, dephosphorisation rate of high phosphorus hematite is more than 60 per cent by æsolid state reduction roasting-magnetic separationÆ process while that is up to 80 per cent by iron nugget process. This study can provide theoretical and technical basis on economical and rational use of high phosphorus oolitic hematite.CITATION:Han, H, Duan, D, Zhou, E and Wang, W, 2013. New methods for high phosphorus oolitic hematite dephosphorisation by direct reduction process, in Proceedings Iron Ore 2013, pp 391-396 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 12, 2013

By Jamsa-Jouneia SL, Lahteenmaki S

Sophisticated control systems require sufficient and reliable information from the process to be controlled. At the Pyhasalmi concentrator two novel measurements, a particle size indicator (PSI) and a mill level monitor (MLM), have led to significant progress in the control of the grinding circuit. The PSI and the MLM measurements have brought additional information from the process. The PSI has been an absolute prerequisite for determining the overall grinding circuit efficiency and the design of the integrated grinding and flotation control system. The MLM measurement has enabled studies on the volumetric filling of a mill to be utilised for maximising the mill throughput. The paper describes the operation principles of the PSI and MLM devices and the additional process information received. The results of a metallurgical pre-control audit are discussed and finally the design of the integrated control system is outlined.

Jan 1, 1993

By Jim Freeman

After testing 30 fourth year mechanical trade school students with our final mechanical apprentice test, only one passed. ?Most western technical trade school students tested ?Test result average was 52% ?NMC graduating apprentice average is 78% (75% passing requirement) ?Our mechanical test has 200 questions; Electrical test 110 questions

Jan 1, 2010

By John R. Sturgul, Elizabeth Yost

The number of Native Americans presently working as mining engineers is extremely low-perhaps three in the entire US. At the New Mexico Institute of Mining and Technology, it was felt that introducing high ability students to mining engineering at the high school level would encourage more to consider mining engineering as a career. New Mexico Tech, in Socorro, NM, has initiated a continuing summer college program for Native American high school students. The program, which began in the summer of 1980, is designed to introduce participants to college life, enrich their high school curricula, and expose them to the problems and challenges of a career in mining and related engineering fields. Students From reservations throughout New Mexico with a demonstrated aptitude for science and mathematics were encouraged to apply for admission. Preference was given to high school sophomores and juniors since it is hoped that students will want to return for a second year before graduating from high school and beginning university studies. The program seeks to impress upon the students the need fir Native Americans in the fields of seience and mineral engineering.

Jan 7, 1981

By Kjell Winther

"Hydralift Scanmec introduced early in the eighties a new and different mill design for very large grinding mills. The design described has actually no size limitation upwards and is so far suggested with motor power up to 40 MW. The mill is furnished with gearless ring motor drive transmission. It is totally fabricated, without heavy castings. The first installation, an 8, 1 MW ball mill dia. 6,5 m x 9,65 m length, has been in continous operation in 13 years without problems. Total grinding costs has been reduced with 3 0% compared to traditional smaller mills. Reductions has been achieved in maintenance cost, power consumption, liner wear and grinding media consumption.So far 3 ball mills of the described design are delivered and in operation, one grinding Iron ore and two grinding Nickel ore.IntroductionThe design of mills for mineral ore dressing has basically been unchanged since grinding in mills started some I 00 years ago, in spite of the fact that mills have grown larger and larger. This has resulted in structural and mechanical problems, causing expensive failures and loss of production.Hydralift Scanmec engineers were designing mills for more than 20 years according to the old «rules». As they experienced interest for an increase in the mill size at the time when reports about failing mills were published, they started analyzing the different mill parts to find new solutions. One goal was to only use elements from proven technology in the new design. Two key items were ring motor (wrap around motor)(Isch et al. 1977, Meintrup and Klein 1982, Ranze 1983) and large diameter pad bearings (wrap around bearings)(Fuller 1984), both acknowledged from other industries."

Jan 1, 1995

By Daniel H. McClain

A unique partnership between the Colorado Mine Safety and Training Program (CMSTP), the Colorado Rock Products Association (CRPA) and the Higher Education and Advanced Technology (HEAT)Center resulted in a video CD-ROM training program for new miners entering the aggregate industry. Cooperation from everyone involved, including the U.S. Mine Safety and Health Administration (MSHA),made this the product against which other training materials in the mining industry will be measured in the 21stcentury. This product’s versatility and wide application make it a tool that is as critical to a mine’s success as any earthmoving machine. The state and federal grant money involved allows this product to be affordable to small operators and independent contractors. The quality of this two CD-ROM set rivals any commercially made CD-ROM training.

Jan 1, 2003

By Steve Kral

The upswing in prices for base and precious metals, industrial minerals and coal has allowed the global mining industry to ramp up production at existing mines and begin construction of proposed projects. In addition to satisfying shareholders, the industry is also providing good paying jobs and creating needed infra-structure in places that previously did not have either. However, the industry has learned that the prospect of jobs and infrastructure is not necessarily a guarantee that communities will allow mines to be built. The industry must maintain even higher environmental and reclamation standards. And mining companies must help communities plan for life after a mine is closed and the company moves out.

Jan 1, 2005

By Leonel Lopez

Throughout Mexican history, mining has been an important, traditional activity. Before the "Discovery of America," native miners worked a variety of deposits throughout the country, including Mixtec gold and gem mines in Oaxaca State and Aztec gold, silver and copper from mines in Michoacán. The 500th anniversary of Mining in Mexico after the "Discovery of America" was initiated by the Mexican mining sector on April 15, 1991. As early as 1548, when the Guanajuato mining district was discovered, Mexico had become a leading world producer of precious metals. Since then, Mexican mineral production has developed in cycles, responding to changing technological, economic and political conditions. During the 20th century, Mexican mine output reached its peak in the decades of the 1930s and 1940s, when it was producing about 40% of the world's silver, 15% of its lead, 10% of its zinc, 4% of its copper and 3.5% of its gold. In 1990, by way of contrast, these percentages of world output stood at 13.5% for silver, 4.7% for lead, 4.1% for zinc, 3.2% for copper, and 0.43% for gold. The lowest production levels were recorded during the 1960s and 1970s, when Mexicanization of the industry and increasing state controls weakened mineral economics to a point that mineral exploration budgets were sharply reduced or eliminated, along with the industry's future. Only the noble old mining districts continued to supply production, with occasional eruptions of "bonanzas" and new extensions in established mining districts.

Jan 1, 1994

The GPS and information technology industries are now applying considerable development effort to what is being termed machine control and machine information systems, in particular focusing on the industries the of mining construction and agriculture. GPS based systems are demonstrably finding common acceptance and adding commercial value to many machine applications in industry. This has been the first step in the evolution of the information age that is now reforming mining practices. Adding the technologies of wireless data communication, modem computer databases, and networked PC's mining is on the verge of a new era in overall process management. This paper is a general discussion of what the information age means to miners and a general description of new mining operation technologies available to day from the Caterpillar technology alliance.

Jan 1, 1999

Despite the current economic downturn that is now decimating iron ore production, Minnesota?s mining operators remain optimistic about the long-term prospects for the industry. Reflecting this optimism, the development of several new mining projects continues in the state. The future of mining in Minnesota was the featured topic at the combined 82nd Annual Minnesota Section of SME Meeting and 70th Annual University of Minnesota Mining Symposium. More than 500 mining industry professionals, including engineers, executives, mining managers and equipment suppliers from the around the world, attended the meeting, which was held April 14 and 15, 2009, in Duluth, MN. The combined meeting featured a keynote session with three distinguished speakers plus a panel discussion by representatives from several of Minnesota?s taconite producers. The keynote speakers were Curtis Clark, president and chief operating officer, Behr Dolbear, who gave a presentation on the ?State of the Mining Industry.? Phil Newman, chief operating officer, CRU Strategies, spoke about challenges facing the mining industry and James A. Skurla, acting director, Bureau of Business and Economic Research, Labovitz School of Business and Economics, University of Minnesota Duluth, discussed the importance of mining to northeastern Minnesota?s economy. The taconite producers panel discussion included Jonathan Holmes, vice president and operations manager, ArcelorMittal; Ed Latendresse, vice president and general manger, Hibbing Taconite; John Tuomi, vice president operations services, United Taconite and Mike Mliner, vice president and general manager, Northshore Mining. The mangers provided updates on their respective operation The meeting included concurrent technical papers sessions on mining, processing, environmental and nonferrous mining. The sessions included technical papers that provided information on the status of a number of new mining projects in the state. The conference also offered a SME short course titled ?The basics of iron mining.? A tradeshow that featured about 100 companies and organizations offering products and services to Minnesota?s mining industry ran in conjunction to the conference. It was estimated that more than 900 people, including conference registrants and special invited guests of the vendors, attended the tradeshow opening reception. This was the largest trade show in many years. The Minnesota Section of SME also held its annual business meeting during the conference.

Jan 1, 2009

By Kiyoshi Shibata

A new assessment model has been proposed for metal production and its recycling system. The model consists of three processes, smelting of ore, cascading and upgrading of metal scrap. The present approach is to assess the total energy consumption of the system, by introducing two equations for describing the relationships between critical impurity content and the mass of production or scrap recycling. The total energy consumption in the system can be described as a function of recycling rate and performance of the upgrading process. The present model suggests that the impurity removal efficiency and yield in the upgrading process are essential to reduce the energy consumption in the systems. Especially, such points should be explicitly controlled in recycling of aluminum. The potential capability of this model was also discussed by obtaining several quantitative information required for the process design and the operational control of beneficial recycling of metals.

Jan 1, 1998

By Kim Appleby

Epithermal gold-silver (lead-zinc-copper-manganese) mineralization on Misima Island is confined to steep and reactivated flat-lying normal faults in the upper plate of a major, shallowly dipping detachment fault. The hangingwall comprises an Eocene metavolcano-sedimentary sequence that has been extensively intruded byMiocene calc-alkaline granodiorite. It is unconformably overlain by Pliocene sedimentary and volcanic rocks. High-pressure amphibolite facies rocks dominate the footwall and have many characteristics of a metamorphic core complex. Mafic-alkalic lamprophyre dike swarms intrude the hangingwall and footwall sequences. Previous workers attributed the gold-silver mineralization on Misima to the intrusion of the porphyritic granodiorite (Williamson, 1984). This has been proposed for many tertiary gold deposits of the southwest Pacific(Sillitoe, 1989; Leach and Corbett, 1994).

Jan 1, 1996

By Hani Mitri

Understanding the interaction between rock bolts and underground rock movement is critical for safe and cost effective underground excavation design. Although early research on this subject involved a balance of theoretical analysis and field measurement, recent work has been heavily focused on analytical and numerical studies. This paper describes technologies that have the potential to redress the balance through instrumentation of rock bolts deployed under routine operating conditions in underground mines. Two new products are presented in this paper. Firstly the U-cell coupler is a load cell device that can be routinely coupled to the threaded end of a bolt prior to installation. It measures the ?series? load at the head of the bolt. Secondly, the d-REBAR involves an array of small-diameter, long-base length displacement sensors recessed into grooves along the entire length of the bolt. Both new instruments are interfaced with on-board digital signal conditioning and telemetry. Methodologies for the deployment of the new instrumentation and guidelines are presented for the interpretation of results based on data obtained from field trials. Successful field installations demonstrate the viability and practicality of these new technologies and, moreover, provide important insight in to rock bolt/rock mass interaction.

Jan 1, 2012

By A Hollweg, K H. Esbensen, M Lischka

Two new splitter designs for intercepting moving streams of matter are presented, the variable cross-stream splitter (vCSS) and the rotary stream splitter (RSS), which are intended for implementation in a fully automated modus. The vCSS facilitates obtaining up to three subsamples with different splitting ratios from automated laboratory flow paths, while the RSS divides the intercepted sample into 16 equal analytical aliquots. The splitters can process a wide range of dry, granular and free-flowing materials (<5 mm). The required weight for each subsample can be set without mechanical adjustments in the case of the vCSS. Typical applications are subsampling/splitting for X-ray fluorescence pelletisation (or fused beads) or splitting for average shift composite sampling or grain size analysis. The vCSS combines the advantages of riffle splitting (three user-defined subsample masses) with miniature bed blending and can accept up to 15 kg in total incoming sample mass. In practice, the automated vCSS can deal with unlimited ingoing mass fluxes, while the RSS is designed to operate at a user-defined fixed subsampling rate (1/16th in the tested version). Both splitters have the potential to be optimised and evaluated according to an application/user-defined total sampling error (TSE) + total analytical error (TAE) threshold. Both splitters were tested under adverse conditions and with compositions involving three components with properties representing typical mass fluxes and components concentrations in industrial and technological systems: phosphate concentrate 89.00 per cent (<500 µm), slag ten per cent (>2 mm) and glass spheres one per cent (750–1000 µm). The slag particles vary widely in particle shape, aspect ratio and surface roughness, while the glass spheres are extremely prone to bouncing and segregation (spillage). This test system is extremely difficult to split and thus constitutes a realistic worst-case scenario. While the vCSS does not comply strictly with Theory of Sampling demands for correctness, both splitters may well be able to deliver fit-for-purpose representative results if/when tested properly. Average relative mass deviations ranged from 1.89 per cent for phosphate concentrate (relative standard deviations of 20-fold repeated splitting) to 4.72 per cent for glass spheres and 13.04 per cent for slag. For the RSS, the average replication experiment splitting variation was 2.89 per cent for phosphate concentrate, 4.82 per cent for glass spheres and 11.1 per cent for slag. Both new automated online splitters would therefore appear to be able to be tuned to fit-for-purpose representivity (defined here as maximum relative reproducibility <5 per cent) for many non-extreme materials; however, it is always imperative to test every new type/class of material empirically. There is a wide commercial potential for important materials and commodities sectors, including food, feed, drugs (pharmaceutical), secondary raw materials, recyclates, agricultural products and seeds.CITATION:Lischka, M, Hollweg, A and Esbensen, K H, 2017. New online/atline splitter designs for laboratory automation – feasibility results, in Proceedings Eighth World Conference on Sampling and Blending , pp 159–166 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By M. Hopf, E. Rossouw

Keywords: Pyrometallurgy, furnace, copper coolers, freeze lining, monitoring, Saveway The use of water-cooled copper components as sidewall elements of submerged arc furnaces and other pyrometallurgical applications has become increasingly common. The high cooling efficiency of copper has made it possible to increase the service life of furnace refractories when compared to conventional refractory linings. However even the self-healing effect of ?freezing? worn areas of the lining does not necessarily protect the copper coolers against wear or corrosion completely. In order to avoid furnace explosions, various methods have been used to monitor the wear of coolers. Unfortunately, these have not been able to consistently identify localized wear. Thos Begbie (South African) and SAVEWAY (German) jointly developed technology to embed a line sensor into the copper cooler during the casting process. This system allows an exhaustive monitoring of the copper cooler. A SAVELINE sensor is placed inside the copper-cooling panel between the water-cooling passage and the hot face of the panel. The sensor follows the meandering shape of the cooling water channels. In the first instance, the sensor provides analogue information as the thickness of the copper reduces. Secondly, this wear signal will be confirmed by a signal of interruption if the sensor is washed away. Because of the structure of the sensor, a self-diagnosis is possible and indications can be confirmed (double proofed). Subsequent to the manufacture of some test pieces, coolers for a large submerged arc furnace were manufactured. The sensorized coolers have been installed at the intermittent surface (slag line) where the largest amount of corrosion has been encountered. The system has been operating since December 2005 in what is considered one of the largest submerged arc furnaces in South Africa.

Jan 1, 2006

By M. Hopf

The use of water-cooled copper components as sidewall elements of submerged arc furnaces and other pyrometallurgical applications has become increasingly common. The high cooling efficiency of copper has made it possible to increase the service life of furnace refractories when compared to conventional refractory linings. However, even the self-healing effect of ?freezing? worn areas of the lining does not necessarily protect the copper coolers against wear or corrosion completely. In order to avoid furnace explosions, various methods have been used to monitor the wear of coolers. Unfortunately, these have not been able consistently to identify localized wear. Thos Begbie (South African) and SAVEWAY (German) jointly developed technology to embed a line sensor into the copper cooler during the casting process. This system allows an exhaustive monitoring of the copper cooler. A SAVELINE sensor is placed inside the copper-cooling panel between the water-cooling passage and the hot face of the panel. The sensor follows the meandering shape of the cooling water channels. In the first instance, the sensor provides analogue information as the thickness of the copper reduces. Secondly, this wear signal will be confirmed by a signal of interruption if the sensor is washed away. Because of the structure of the sensor, a self-diagnosis is possible and indications can be confirmed (double proofed).Subsequent to the manufacture of some test pieces, coolers for a large submerged arc furnace were manufactured. The sensorized coolers have been installed at the intermittent surface (slag line) where the largest amount of corrosion has been encountered. The system has been operating since December 2005 in what is considered one of the largest submerged arc furnaces in South Africa. Keywords: Pyrometallurgy, furnace, copper coolers, freeze lining, monitoring, Saveway

Jan 1, 2006

The exploitation of the underground is currently undergoing a major transformation process. Besides mining, alternative ways of utilization are playing an increasingly important role. These alternative utilizations include the storage of gases, the disposal of radioactive wastes and the implementation of geothermal storage facilities. In addition, more and more mining operations are being shut down, like the German hard coal mining industry in 2018. But the integrity of closed mines must be ensured in the post-mining phase.

Jan 7, 2020