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By N September, R Abate

Bateman Modular (previously Van Eck and Lurie) has been building and supplying the mining industry with modular DMS plants for the last 30 years. These DMS modules range in capacity from 1 tph to 200 tph. The most popular unit produced by Bateman Modular over the years has been the 50 tph module. Development In the last 7 years a need has arisen from the industry to provide Modular DMS plants that can treat higher tonnages (150 to 200 tph). The first DMS provided to the mining industry based on the modular concept was a 150 tph DMS Module to MIBA in the DRC. Since then Bateman Modular has provided some 14 Mega DMS modules over the last 7 years with the latest two orders from Debswana (Damtshaa double up project) and Namdeb. Ever since the first Mega Module was supplied Bateman Modular has been improving the Modules. Implementation The modules can be supplied in different configurations so as to improve the overall availability of the plant. Two off 150 tph DMS modules were supplied for a Transhex operation. This allowed the client to still operate one DMS module while maintenance is being performed on the other DMS module. The client also has the option of choosing a single module. Successes The following list of projects provides the base for the success of the Mega Modules.

Jan 1, 2006

By A. Supomo, A. Partanen, M. Mular

Although many SAG operators may agree that on-line measurement of SAG feed-size is an attractive notion, applying this information in a control strategy that recovers the investment, engineering time, and maintenance is not necessarily straightforward. The P. T. Freeport Split-Online system was justified based on the assumption that SAG feed-size could be used in a feed-forward control strategy either at the regulatory or expert system control level. Something like “as the feed size changes adjust the throughput to avoid under or overloading the mill” was envisioned. However, following installation and calibration, Cluster Analysis showed that such an approach would not be successful. However, the sensor has been successfully integrated into Freeport’s grinding control strategy other ways. It provides an input to the Kalman filter parameter estimator used in a model-based control strategy that optimizes throughput and grind. The Split sensor also provides a characteristic feed size parameter for use in an on-line work index estimator. This paper describes the calibration and installation of the Split SAG feed-size analyzer, and reviews the evolution of its use in the Freeport C3 grinding circuit control strategy.

Jan 1, 2001

The gold salting fraud at Busang on the island of Kalimantan, Indonesia was exposed in early 1997 and resulted from the independent drilling, sampling and assaying of PT Freeport Indonesia which reported assays from the South East Zone with negligible concentrations of gold. Since then, a number of legal actions directed at former Bre-X directors, consulting firms and financial or broking institutions are at various stages and are based on numerous allegations surrounding the supposed existence of obvious and numerous warning signs or æred flagsÆ. These include: the absence of references to visible gold in the drill logs; the alluvial nature of the gold grains; the high gravity recoveries; the invalid comparison with Kelian; the absence of outside scrutiny and the lack of external review/audit and surface depletion of gold. The focus on the red flags has been at the expense of the numerous positive indications or ægreen flagsÆ. These include the morphology and chemistry of the gold grains, the gravity testwork, the amalgamation results, the role of external consultants, the results of a review by one of North AmericaÆs leading minerals auditing groups, the behaviour of the gold at surface and the presence of references to visible gold in the drill logs. The flawed nature of the discussion of the technical facts surrounding Busang has prevented a meaningful and informed discussion about what actually happened and has, therefore, prevented the formulation of meaningful remedies for the future.

Jan 1, 2002

By Steve Kral

The mining industry in Colorado faces the same problems the industry faces throughout the United States and the world — record low commodity prices and increasing regulatory and environmental restrictions that seemed designed to curtail mining activities. Despite those obstacles, the mining industry in Colorado still contributes about $8 billion annually to the state’s economy in the form of base and precious metals, industrial minerals, coal and associated service businesses and jobs. So the 300 attendees at the102nd National Western Mining Conference felt reason-ably positive about the industry in their state. The meeting is the Colorado Mining Association’s annual conference and was held at the Broadmoor Hotel in Colorado Springs in November. The theme was “Mining in the New Millennium — Achievement + Innovation = Survival.” Experts from Colorado’s mining industry and abroad discussed the challenges faced by the mining industry as it enters the new millennium. They offered insights into how the industry will operate during the early years of the 21st century and how it will survive low prices and increased regulatory restrictions.

Jan 1, 2000

By K. Hennings

Noise from vibrating screens is generated in two ways: 1) Noise due to the material being processed and, 2) noise from the screen itself. Non-metallic decks had been shown previously to reduce material noise. The noise reduction and change in screening performance was quantified for six non-metallic decks using dolomite, granite and coal as the materials. The non-metallic decks were from 2 to 7 dBA quieter and from -1 to +10 percent less efficient as compared to a steel wire cloth deck of the same open area. Damping of the sidewalls and isolation of the drive mechanisms had been shown, in a development configuration, to reduce the noise of the screen itself. Tests of four prototype damping treatments gave reductions up to 4.9 dBA and the mechanism isolators gave an additional 2.1 dBA. The treatments were successfully life tested in two ways: 1) Lab tests to a simulated 25,000 hours were conducted on samples of the treatments in a corrosive salt spray to simulate coal plant wash water and, 2) the full size treatments were run on a full size screen for 5,000 hours.

Jan 1, 1980

By Danny Riley, Brian Curry, Sandya Govindaraju, James Bain

Hand arm vibration syndrome (HAVS) affects industrial workers exposed to long term hand-transmitted vibration from powered-tools. Peripheral neuropathy is a major component of the symptom complex of HAVS. Long term exposure to vibration causes myelin damage in peripheral nerves and reduces nerve conduction velocities in rats1. This study addresses the effects of acute vibration at constant acceleration of 49 m/s2 on myelinated fibers in peripheral nerves in Sprague-Dawley male rats using the ‘rat-tail vibration model,’ which simulates hand-transmitted vibration2. Methods Male Sprague-Dawley rats (~300 g) were assigned to vibration groups: 1 hr continuous vibration at 60 Hz; 4 hr continuous exposure at frequencies of 30, 60, 120 or 800 Hz; immediate and 24 hr following a 4-hr cumulative exposure of continuous and intermittent vibration at 60 Hz. Unanesthetized rats were restrained in cages on a nonvibrating platform with their tails placed on a vibrating stage accelerated by a B&K motor type 4809 and vibrated. Intermittent vibration was delivered in bouts of 10 min vibration alternating with 5 min rest periods repeated over 6 hr. Sham controls were restrained without vibration. After vibration exposure, the rats were anaesthetized, and the ventral nerve trunks from the proximal tail segment 7 were fixed in glutaraldehyde, embedded in epon-araldite and sectioned at 0.5 µm thickness and stained with toludine-blue for morphological quantitative analysis. The total number of myelinated axons in each cross-section of the nerve was counted using the Image J software. Myelin damage was identified by focal increase in area and intensity of toludine-blue staining and unraveling of the myelin sheath. Statistical analysis for comparing sham and the different vibration groups was done using Dunnett’s test. Animal treatment and all surgical procedures were approved by the institutional review board and compiled with the Laboratory Animal Welfare Act. Results The rats tolerated continuous vibration very well and exhibited no behavioral signs of stress. When exposed to intermittent vibration, there was increased vocalization, a startle reflex at the beginning of each bout of vibration, deposition of porphyrin around the eyes and transient hypersensitivity to touch.

Jan 6, 2006

By Yuemin Zhao, Daniel Tao, Xinxi Zhang, Qingru Chen, Maoming Fan, Zhenfu Luo, Xiuxiang Tao, Guohua Yang

Coal is currently cleaned with the minimum of size reduction, fine particle processing, recovery, and tailings disposal are major problems. Adequate water resources are not always available. For example, two thirds of China's coal is located in arid areas. Hence, dry separation provides an alternative approach. Of the dry coal separation methods available, air dense-medium fluidized beds have been used to separate 50~6mm coal efficiently. However, excessive bubbling and back mixing of the separated solids in the air-dense media fluidized bed causes the high lower size limit of 6mm for the feed material, this affecting the preparation efficiency. Based on prior study on air-fluidized dense media for 6~50mm coal preparation, this paper presents methods and test results on the fine coal dry classification, static electricity beneficiation of 0~0.5mm coal, and magnetically stabilized fluidized beds for separating 0.5~6mm coal.

Jan 1, 2005

By Vilma Beltrán

Dado que los trabajos de procesamiento metalúrgico de la mina Uchucchahua, ocasionaron impactos en el medio ambiente, afectando la calidad del agua y eliminando la vida acuática en las lagunas Añilcocha, Colquicocha y Tinquicocha, se procedió a encontrar una alternativa de tratamiento biológico que recupere la calidad de vida en la mina Uchucchacua. En este sentido, el presente trabajo describe el tratamiento pasivo de los efluentes con manganeso de la mina Uchucchacua. Para dicho procedimiento, se desarrollaron trabajos en dos etapas: el de laboratorio y balde. El primero comprende los sistemas de tratamiento pasivo anaeróbico y aeróbico.El aeróbico se inició sobre la base de los procesos de filtración y aireación a fin de determinar el grado de oxidación y precipitación del manganeso como óxido, mientras que el segundo se realizó en función a los resultados obtenidos en la etapa laboratorio y comprende los siguientes procesos: filtración, autooxidación, aireación, sedimentación. En consecuencia, los procesos anaeróbicos no favorecen la reducción de Mn II en los efluentes estudiados, mientras que los procesos aeróbicos permitieron la disminución del manganeso.

Sep 13, 2001

By Brian P. Waagner

Construction law in general and the law of deep foundations in particular continues to develop rapidly, particularly in the areas of risk allocation. Public and private owners are increasingly using contractual disclaimers to shift the risk of differing site conditions to contractors, and courts are increasingly willing to enforce these contractual devices. Perhaps also in an effort to control costs, public and private owners are turning to design-build contracting techniques. While design-build offers many advantages over traditional project delivery systems, it does not answer all of the risk-allocation questions that frequently arise. Even in design-build, problems with unanticipated subsurface conditions and defective design are not easily addressed. Finally, developments in electronic commerce present the potential to transform the construction industry.

Jan 1, 2002

By I. A. Mwamba

Plain and alloyed titanium aluminides of composition Ti-47.5 at.% Al were prepared by melting commercial-purity titanium and aluminium with additions of 1 at.% precious metal. The as-cast alloys were subjected to potentiodynamic scans in 5, 15, and 25 wt% HCl aqueous solutions at room temperature and compared for their abilities to spontaneously passivate. Addition of precious metals resulted in a general improvement of corrosion resistance by increasing the open circuit potential to more noble values. Addition of 1 at.% gold or silver to titanium aluminide did not significantly increase the corrosion potential (Ecorr) above that of the plain titanium aluminide alloy, indicating that gold and silver are not sufficient cathodic modifiers to improve the corrosion resistance of titanium aluminide in all the solutions tested. However, platinum, palladium, and iridium additions shifted the corrosion potentials to the position of the passive region of plain TiAl for all solution concentrations. This indicated that TiAl alloyed with these platinum group metals would passivate spontaneously by cathodic modification. TiAl alloyed with palladium performed the best in 5 wt% HCl solution with the most positive corrosion potential. In 15 wt% HCl solution, alloys with platinum exhibited the most positive corrosion potentials, while alloying with iridium or palladium revealed more negative corrosion potentials. Thus, palladium alloying led to the best cathodic modification of titanium aluminide in low-concentration HCl solution, whereas platinum and iridium alloying additions resulted in the best cathodic modification of titanium aluminide in high-concentration HCl solutions.

Jan 1, 2013

In the USA, the National Institute for Occupational Safety and Health (NIOSH) does a lot of work and has provided news of interesting new developments. Marcia L. Harris describes an ?Explosibility Meter: ?In underground mines, coal dust explosions are prevented by the addition of rock dust sufficient to render the coal dust inert. Federal [US] regulations require 65% and 80% incombustible content in samples taken in intake airways and return airways, respectively, assuming a nominal coal dust size of 20% minus 200 mesh. The Coal Dust Explosibility Meter (CDEM), a hand-held instrument developed by NIOSH uses optical reflectance to measure the explosibility of a rock dust and coal dust mixture.? The CDEM is now commercially available. It provides real-time results during rock dust surveys instead of waiting weeks for laboratory results1. ?With real-time results, the potential for a disaster can be mitigated immediately. The CDEM displays the percent incombustible content as well as a colour indicating the relative explosibility of the coal and rock dust mixture. A red read-out indicates that more incombustible material is required to inert the coal and rock dust sample, while a green read-out indicates that the dust sample is sufficiently inert. When the mixture is marginally explosible, a yellow read-out is indicated. The red-yellow-green output depends upon the particle size distribution of the rock and coal dust mixture with the finer size fraction being more explosible.?

Jan 1, 2008

By S. Finsterle, R. C. Trautz

We performed numerical modeling studies to investigate water seepage into underground openings excavated in unsaturated fractured rock. Water seepage is a key factor affecting the performance of a nuclear waste repository such as the one proposed at Yucca Mountain, Nevada. The amount of water dripping into an underground opening depends on the connectivity and permeability of the fracture network as well as on the capillarity of individual fractures intersecting the opening. We developed a high-resolution numerical model of an unsaturated fracture network and examined the appropriateness of seepage predictions using a fracture-continuum model. Model calibrations to liquid-release tests performed at Yucca Mountain are also discussed.

Jan 1, 2000

Kinetic Dependence of Refractory Gold Sulfide Biooxidation Using Different Microorganism Association In this investigation, refractory sulfide concentrate from a deposit located in northern Russia was treated using biohydrometallurgical technology. The objective of this work was to compare the accelerated refractory sulfide concentrate biooxidation abilities of the pure and mixed mesophilic and moderately termophilic acidophiles cultures. Pure culture of Acidithiobacillus ferrooxidans and two associations of the: Acidithiobacillus ferrooxidans + Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans + Acidithiobacillus thiooxidans + Leptospirillum + Sulfobacillus were used in this investigation. Results of sulfide concentrate bioleaching were analysed using the enzyme catalysis theory. Different effective kinetics parameters were calculated for Michaelis-Menten equation, such as Michaelis' constant and maximum rate of the enzymatic reaction. It was shown that the increase of microorganisms' species decreased Michaelis' constant. Lower Michaelis' constant characterises increasing bacteria ferment affinity to substrate (treated concentrate). As a result, the rates of sulfide minerals biooxidation have increased. This investigation has demonstrated that cultures of the different microorganism species, including moderately termophilic, allow to enhance different parameters of the biohydrometallurgical technology for the refractory gold sulfide concentrate treatment. We can see that bacterial leaching stage duration decreased and sulfide minerals oxidation increased. When the bioresidues were subjected to the hydrometallurgical stage, which includes aeration and sorption cyanidation, the operation factors were also enhanced. The decrease of aeration duration and the growth of the precious metal extraction by sorption cyanidation was achieved. Cyanide consumption was also reduced. The results of this investigation were used in design of an industrial plant.

Sep 13, 2010

By Ettore Contestabile, Cameron Thomas

Implosive connectors such as XECONEXTn have been used extensively for joining electrical conductors. This implosive action of explosives has also been used in other forms of high-energy metal working with excellent results. However, the inherent blast energy of these units can cause environmental side effects (especially airblast) which may restrict their use around inhabited areas.

Jan 1, 1994

Project Schedule ?Construction 2005 ?2008 (3 years) ?Operations mid 2008 ?2020 (12 years) ?Closure 2020 ?2023 (3 years) ?Post-closure monitoring Victor Economic Facts ?$982 million investment; ?$110 million already invested in the Project; ?1100 person years of employment in construction; ?375 full time positions during operations;

May 1, 2006

By M. J. Sapko

The design requirements for mine ventilation seals have undergone a radical transformation in recent years, and these revisions have greatly increased the cost of the seal designs and their construction. For example, in the past two years, new federal regulations have increased the minimum design requirement to withstand explosion pressures from 138 kPa (20 psig) to 345 kPa (50 psig) or 827 kPa (120 psig), depending on whether the sealed mine volume is monitored continuously or not. Moreover, there is still a possibility that under certain conditions (such as detonations) even higher pressure requirements may be necessary. The ability of a monolithic, stand-alone mine seal to reliably withstand the full range of current and future pressures is becoming increasingly difficult and expensive. In an effort to develop a practical alternative, the West Virginia Office of Miners? Health Safety and Training (WVOMHST) and the National Institute for Occupational Safety and Health (NIOSH) have collaborated in a research effort to develop a practical, economic, and safe mine sealing technique that can enable mines seals to meet the full range of new explosion pressure design requirements. The basic idea is to use a barrier of common mine gob and rubble in combination with a conventional mine seal so that the pressure resulting from a gas explosion is reflected, absorbed, and attenuated, so the pressure on the ventilation seal is reduced. This paper discusses some concepts and preliminary test results for a ?Passive Mine Blast Attenuator? (PMBA) that can provide a useful alternative to increasingly larger and stronger stand-alone mine seals. Numerical models and full-scale experiments conducted at the NIOSH Lake Lynn Laboratory Experimental Mine (LLEM) show that the use of a PMBA can signficantly reduce the blast pressure and impulse on conventional ventilation seals. DISCLAIMER: This information is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has not been formally disseminated by the National Institute for Occupational Safety and Health (NIOSH). It does not represent and should not be construed to represent any agency determination or policy.

Jan 1, 2009

By Carnevale Francesco, Bracci Laudiero Alberto, Pampanin Piero

"SummaryIn the Port of Naples a slurry wall has been realized through a sandy layer up to a deep tuff layer using the Cutting Soil Mixing technique.The executed panels have dimensions of 2.8 m x0.65 m in plan and a total length of 25 m. Primary and secondary panels have been executed using the wet to wet technique. During the panels execution the following parameters had been measured: injection pressure, injected volume, verticality. At the end of the works an exploratory campaign has been carried out through boreholes collecting samples for laboratory tests in order to verify the diaphragm thickness and its physical and mechanical properties (i.e. unit weight, unconfined compressive strength).The interpretation of the collected data allowed to verify the efficiency of the method, the volume of slurry loss due to permeation during the panels execution, the quantity of the obtained spoil compared to the volume balance equation, both for the sand and the tuff layer.Eventually, the measured physical and mechanical characteristics of the panels have been correlated to the execution method performed.IntroductionIn the Naples Port area there is a polluted site which has to be hydraulically isolated in order to prevent the pollution of the groundwater that flows from land to the sea through the Port area. A hydraulic cut-off wall has to be realized and particularly a slurry-wall realized using the CSM method had been executed.To date, two stretches have been executed, 140 an 110 m in length respectively, as shown in Figure 1 and Figure 2.After execution, the slurry-walls have been investigated with boreholes. In-situ and laboratory tests on the recovered samples of grout have been carried out; furthermore, the geotechnical parameters of the mix composing the wall have been measured."

Jan 1, 2014

By Harry D. Lewis

Gilsonite is a lustrous black material that can be easily crushed into a chocolate-colored powder. It is a solid but relatively soft, lightweight hydrocarbon that visually resembles the volcanic glass obsidian. It was once thought to be a type of coal, but because it is thermoplastic it melts rather than bums. Gilsonite is found in commercial quantities only in the Uinta Basin of eastern Utah and western Colorado, where it forms vertical, nearly parallel veins of varying depth, width, and length. Gilsonite from different veins has different properties, most notably variations in softening point and solubility. These differences result in its use in a variety of industrial applications. Gilsonite's earliest commercial uses were in varnishes, buggy paints, and beer vat linings. Eventually it came to be used in more than 160 products ranging from inks to explosives. It is exported from the United States to most industrialized countries throughout the world. Today, due to competition from synthetics and other hydrocarbon products, its use has narrowed to several specific industries. Although sold mostly as a commodity, current research is focused on applications for gilsonite as a value added product. Historical Overview The discovery of gold in California and the dawn of the mining era in Nevada, Colorado, and Utah around 1850 brought a wave of prospectors to the western United States. One of those pioneers, Samuel H. Gilson, is generally credited with a major role in the discovery of gilsonite. The material now known as gilsonite was discovered several times from the late 1860s through the mid-1880s. It was William P. Blake who, after receiving samples of the material, wrote a paper in 1885 describing "a new variety of asphaltum from the Uinta Mountains." He termed the material uintaite. Although Sam Gilson was not the first to discover the mineral, he was an-inventor who used gilsonite in products that he patented. It was his conviction that the substance was of great value, which caused some to refer to it as gilsonite. The term Gilsonite became the registered trademark of the American Gilsonite Co., and it continues to be in use today. When the first company was formed to mine this substance in 1886 it was named the Gilsonite Manufacturing Co. This firm acquired many gilsonite mining claims and marketed a varnish made from the material. It was the unusual properties of gilsonite varnish that attracted the attention of Adolphus Busch of the Anheuser-Busch Brewing Co. In 1889 Anheuser-Busch bought out Gilson's interests and formed the Gilson Asphaltum Co. Busch had been importing asphalt from Sicily for use in lining beer barrels and saw gilsonite as being more readily available and cheaper. Although gilsonite did not work well in this application, Busch did acquire a large number of mining claims in the Uinta Basin. In 1903 the parent firm of Gilson Asphaltum financed the building of an 85-km railroad from near Grand Junction, CO, to Dragon, UT, to haul gilsonite ore to market. Underground mining was initially centered near Dragon and then later at Bonanza, UT, as different veins were mined. The railway was abandoned in 1937 in favor of truck transportation. In 1938 Gilson Asphaltum changed its name to Barber Asphalt Co., the predecessor of Barber Oil Corp. In 1946 Barber Oil teamed with Standard Oil of California to form a partnership, American Gilsonite Co., which today has its operational headquarters at Bonanza, UT. Barber Oil investigated many new uses for gilsonite, including the making of petroleum derivatives such as gasoline. This work led to the construction of a 116-km pipeline to carry slurried gilsonite to a refinery in Colorado for the production of gasoline, fuel oil, and coke. Pipeline operations began in 1957 but stopped when the economics of competing with petroleum became unfavorable, and the refinery was sold in 1973. In 1981 Standard Oil (later Chevron) became the sole owner of American Gilsonite and remained so until 1991, when it sold its interest to Stratford Enterprises Co. of Tulsa, OK. The companies have since been merged and now operate under the name American Gilsonite Co. with headquarters in Salt Lake City, UT. American Gilsonite continues to be the world's largest miner and supplier of the mineral. The American Asphalt Association was formed in 1902 by former stockholders in Gilson Asphaltum. This company mined various gilsonite claims until it was dissolved in 1953 and its properties were sold to American Gilsonite and Gordon S. Ziegler and Associates. The Utah Gilsonite Co. was established in 1920 and mined several claims until 1952, when its holdings were sold to Gordon Ziegler. Several other gilsonite mining ventures have been pursued in Utah, although they were significantly smaller in scale than those described above. There are currently three companies which mine gilsonite resin in Utah. They are American Gilsonite Co., Ziegler Chemical & Mineral Corp., and Lexco.

Jan 1, 1994

By Phillip Martin Warren

Safety and productivity are critical factors in the performance of the Australian Mining Industry. In this sense, the paper point out that while the multiple dimensions of both training and productivity make it difficult to quantify the relationship, it is clear from this study that organizations that conduct training consider that there is a very positive link. Training is seen as a very important activity by the vast majority of organizations surveyed, and is an activity from which they consider they are gaining significant, and often very substantial productivity benefits. Therefore, it predicts well for productivity of Australian enterprises which invest in training.

Sep 13, 2001

By R. V. Ramani

This report is volume 10 of an eleven-volume final report for a Grant completed by The Pennsylvania State University for the Bureau of Mines to develop a dynamic general purpose computer simulation model for underground coal mining. The simulator developed under the Grant has a wide range of possible applications in the design and evaluation of underground coal mining systems from the standpoints of health and safety, productivity, and mine environment. The Master Design Simulator consists of nine free-standing function-oriented subsystem models linked together into an integrated, comprehensive model of an entire mining system. The subsystems comprising the Master Design Simulator include geology and reserves, methane generation, roof support, subsidence, production, rail haulage, cost, water generation, and ventilation. This volume of the final report describes the Ventilation subsystem of the Master Design Simulator. The Ventilation subsystem has the capabilities to handle: (1) branches in parallel or series, (2) fans in parallel or series, (3) multiple fans, (4) methane, compressed air, or other injections into the system, (5) leakages and fixed quantities, and (6) calculations of absolute pressure at nodes. The program uses the Kirchoff's Junction and mesh laws, and the Hardy-Cross iterative technique to converge to the desired accuracy in solving fox the head quantity. A case study is included in the report illustrating the use of the model. The appendices of the report constitute a user's manual for the Ventilation subsystem, and include a program listing.

Jan 1, 1975