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By Eldon C. Pattee

Reconnaisance samples of reported beryllium occurrences in Idaho, Washington, Montana, and Oregon were chemically and spectroscopically tested in a mobile laboratory. The two predominant types of occurrences were green beryl associated with Cretaceous intrusions and disseminated aquamarine associated with Tertiary intrusions. Although the beryllium content of known deposits in the Northwest is too low for economic development at present, total submarginal-grade beryllium resources in pegmatites are estimated to be 570,000 to 1,870,000 tons containing 0.024 to 0.167 BeO. A potential source of 500,000 to 700,000 tons of beryllium-bearing tactite in Idaho and Montana averages 0.033 to 0.080 percent BeO.

Jan 1, 1968

By Klaus Hasselwander

Fluctuating SO2 gas streams represent a difficult task for designers of SO2 removal systems (with respect to designing the plant), but in spite of the designers great efforts to solve the problems, the operation of such plants requires much care and attention. A fluctuating gas flow usually results from metallurgical smelting processes. Both gas composition and gas flow rate may vary. The first part of this paper outlines some existing technical solutions and presents the Pros and Cons of the different solutions. These solutions outline are: - Sulphuric acid plants operated with a preheater permanent in operation - Sulphuric acid plants with concentration increase of SO2 gas either using regenerative SO2 removal or cryogenic partial condensation of the SO2 - Sulphuric acid plants with additional burning of sulfur to increase SO2 content - Single-stage sulphuric acid plants followed by a tail gas system (which is) designed for periods of low SO2 input In the second part, this paper describes some existing technical solutions for removal of SO2 at low concentrations (i. e. less than 0.1 - 2 %-by volume), which could be used as tail gas treatment system for acid plants. While selecting an appropriate solution, special attention should be given to operating costs, which usually to a large extend depends on the type of absorption agent and the costs for disposal of the sulfur compound produced.

Jan 1, 2009

By R. L. de Beauchamp

A preliminary investigation was made of the extraction of chromium from ferrochromium by low-temperature chlorination in the 3400 to 5250 C range. The objective was to devise a method for separating chromium from iron in high-carbon ferrochromium produced from domestic chromite concentrates. The majority of iron was removed as a volatile chloride; chromium was contained in the residue as a nonvolatile chloride, which was separated from carbon and unattacked ferrochromium by dissolution. A small rotary chlorination apparatus was designed, built, and used for the chlorination tests, and samples of commercial-grade high-and low-carbon ferrochromiums were chlorinated for comparison of chlorination characteristics. Low-temperature chlorination of three types of ferrochromium resulted in the removal of 81.9 to 91.6 percent of the iron content as sublimed FeC13. Recovery of chromium in a leach solution of the reactor product varied from 82.4 to 93.1 percent.

Jan 1, 1968

By D. C. Fleck

Electrorefining yttrium from selected low-melting yttrium--base alloys is investigated, and various halide systems are studied as potential electrolytes for use in preparing low-oxygen yttrium by electrorefining unalloyed yttrium. Yttrium cathode products having significantly less metallic impurities than the anode materials were prepared from alloys containing nickel, iron, and manganese by electrorefining in LiCl-YC13 electrolytes at 900° to 1,000° C. Yttrium-copper and yttrium-magnesium alloys are not suitable as anode feed materials, An evaluation of chloride, fluoride, bromide, and mixed chloride-fluoride electrolytes showed that cathode products containing much less oxygen than the anode material can be obtained in the fluoride and mixed chloride-fluoride systems. Initial cathode current density has no apparent effect on the purity of the products obtained in both phases of the investigation.

Jan 1, 1973

By L. Hanschar, C. Bwalya, E. Mokola, K. Musonda, A. Makayi

This paper describes the installation, commissioning and operation of porous plugs featuring nitrogen gas purging in both Anode Furnaces at the Kansanshi Copper Smelter (KCS), a greenfield copper smelter which commenced operation in March 2015. The decision to install porous plugs was taken in November 2016 and the facilities were successfully commissioned on both anode furnaces in October 2017. The project was successful and has demonstrated the following process improvements: 12.2% reduction in main burner fuel consumption Larger average charge size, due to fewer accretions; 17 minute decrease in average refining cycle times Improvements in slag skimming operations Improved casting rates INTRODUCTION Porous plugs The application of porous plug technology in copper smelter anode furnaces is well established around the world. Vukovic and Gamweger (2017) and Wallner (2004) noted that the stirring and mixing action induced by the injection of inert nitrogen gas into the molten copper via porous plugs has potential benefits in the following areas: Homogenization of the temperature and composition of the molten copper resulting in Reduced fuel consumption Less tendency to overheat slag (reduced risk of refractory attack) Less slag produced with a lower degree of oxidation (lower rate of refractory wear) Less tendency for buildups to form Improved environmental performance (produce low sulphur blister at Peirce Smith converters) Elimination of buildups inside the furnace and potential for larger charges per cycle Reduced processing times and potential for shorter cycle times More efficient skimming of anode slag Shorter skimming time Less copper carry over to Peirce Smith converters Very little slag remaining in the furnace (reduced potential for buildups to form)

Jan 1, 2019

By Earl Redman

The Juneau Gold Belt portion of the Juneau Mining District has historically had the greatest mining and exploration activity within the district. Between 1880 and 1983, the mines within the Juneau Gold Belt produced 6.7 MM oz gold, 3.1 MM oz silver, and 45 MM lbs lead, which had a total value of about $157,000,000 at the time of production. This report summarizes Bureau of Mines work completed in 1986, the second year of the Juneau Mining District study. Fifty mines, prospects, and occurrences were examined and 638 samples were collected for analysis during 1986. Metallurgical samples were collected from seven deposits and preliminary tests of cyanide amenability have been completed for five of these. The simultaneous discovery by private industry and the Bureau of gold-bearing quartz veins cutting diorite gneiss recently exposed by the retreat of the Herbert Glacier is the most notable result of work during 1986. This location yielded gold values up to 7 oz/st.

Jan 1, 2011

Recently, work was carried out by the Shotcrete Working Group to study anisotropy in steel fibre reinforced shotcrete using strain-controlled, compressive strength testing methods. The shotcrete materials used and specimen preparation procedures as well as testing methods are described. The test results are discussed and it is concluded that, because of the anisotropic nature of fibre reinforced shotcrete, it may be worthwhile investigating the degree of such anisotropy in practice using strain-controlled, strength testing techniques.

Jan 1, 2001

By A T. Job, M L. Edgar, P R. McAree

Characterising ores in-pit and in real-time presents a significant value opportunity for the mining industry. Hyperspectral imaging systems are proposed as an enabling technology to achieve this real-time characterisation. This paper considers the application of a hyperspectral imaging spectrometer mounted on a shovel. We define the performance requirements for such a spectrometer and associated subsystems during a typical dig-load cycle. The relatively high swing rotation speed of the shovel requires approximately video-rate exposure times to achieve good spatial resolution. We analyse a selection of components against these requirements and find that suitable commercial spectrometers, detectors and optics appear fit-for-purpose. Automated, real-time spectral classification systems are also available, with only relatively modest requirements for processing power. The paper argues that at near peak solar illumination, a system for field deployment at the required sensitivity is viable using only commercial off-the-shelf components.CITATION:Job, A T, Edgar, M L and McAree, P R, 2017. Real-time shovel-mounted coal or ore sensing, in Proceedings Iron Ore 2017, pp 397–406 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By C. E. M. Meskers

End-of-life Electronic and Electrical Equipment, o_cially called WEEE, is unjustly regarded as mainly a waste management problem. What is structurally overlooked is the enormous resource impact of these devices. EEE rep- resents a tremendous metal resource, which should be uti- lized through e_ective recycling, which has a much lower environmental footprint than primary production. The actual amount of end-of-life EEE recycled today is embar- rassingly low since insu_cient EEE is collected and part of the collected EEE is exported to developing countries, where it is largely not entering o_cial recycling systems. To achieve a global recycling society issues like technol- ogy, economics, life cycle structure, stakeholder aware- ness and legislation have to be addressed in a global, co-operative manner so that sustainable closed product cycles can be obtained. Requirements for a "global re- cycling society" are de_ned to address today's reality of global ows of used consumer products, taking into ac- count the likely needs of the future.

Jan 1, 2009

The largest investment in mining equipment in Caterpillar?s history ? The F series mechanical and electrical drive trucks ? is rapidly advancing. Caterpillar showcased the 793F and 797F mechanical drive trucks and the 795F ac electric drive truck at MinExpo in 2008 and have continued testing since then. The 793F and the 797F have accumulated more than 75,000 hours of field testing and have proven their performance capabilities and their durability. The new Cat C175 engine that powers them has racked up 130,000 hours of field testing in mining trucks and more than 120,000 hours in power systems. Because of the success of these field-follow programs, the 793F is targeted to go into full production within a few months and the 797F late this year. Caterpillar engineers have been testing two 795F ac prototypes at the Tucson Proving Grounds in Arizona. The development program has provided input for the construction of a new 795F ac in Decatur, IL. The new truck recently shipped to a copper mine in North America where it will serve as the first field-follow 795F ac as it works at the mine. The 313-t- (345-st-) capacity 795F ac will enter a new size class for Caterpillar, and, as a result, the primary focus of the Caterpillar ac electric program has been on the 795F ac. The commercial launch date will be defined as the field-follow program progresses. ?It?s fitting that soon after producing the 50,000th Cat off-highway truck, we are now shipping our first ultra-class ac electric drive truck to a mine,? said Chris Curfman, president of Caterpillar Global Mining. ?Our new trucks further solidify our position as the one manufacturer to provide unparalleled options and unmatched customer support.?

Jan 1, 2009

By W. Sondermann

"AbstractWith the increasing demand in reuse of inner city areas and the urgent need for deeper foundation pits under cramped circumstances, adjacent structures close to and high ground water level, the well-known established technologies especially with small to mid-sized dimensions are often too time consuming and occasionally not economic to install lateral support systems. The alternatives for these specific cases could be the usage of the deep mixing technology to create lateral support systems in reinforcing the deep mixing elements additionally to transfer the horizontal loads from earth – and water-pressure.With increasing demand in depth and water tightness, verticality and overlapping of single column solutions are becoming the key in execution. In addition, for some applications subsoil-conditions were not ideal for wet deep mixing technologies. The tubular soil mixing system (TSM) as a combination of mechanical mixing and support of hydraulic cutting by jet grouting can provide solutions toovercome these challenges.1. Current market conditions and trendsThe present financial crisis and the efforts not only to consolidate national budgets, but also to rescue certain banks, have not left the building industry unaffected either. Some drastic cutbacks to public budgets, along with the increasingly restrictive granting of credit for the financing of construction projects, have led to enormous over-capacities in the building sector, with purely negative impact. As a consequence of these negative developments, many companies are experiencing the pressure to restructure more quickly and to reduce costs but at the same time to keep the consequences of all activities, both externally and internally, within limits acceptable to employees, owners and finance institutions and last but not least consumers."

Jan 1, 2014

By Paul Hosford, Tim Haldane

"The paper describes the fast-track development of the project from feasibility study through to detailed design and construction, highlighting the process adaptations for handling sticky ore and water management in a tropical environment, and subsequent commissioning and operating experience of the mine. The paper discusses the geological setting, the environmental and socioeconomic considerations in developing and operating a mining operation in an underdeveloped country and the logistical challenges involved in bringing a large capital investment into Central America.INTRODUCTIONGlamis Gold Ltd. acquired the San Martin project in Honduras as a result of its merger with Mar-West Resources in late 1998. Despite the prevailing low gold price environment at the time of acquisition, Glamis anticipated rapid development of the San Martin project due to the quality of the deposit and other positive factors.Following favorable exploration and permitting activities in the first half of 1999, Glamis prepared a Feasibility study. In October 1999, Glamis decided to proceed with the development of the project and selected Hatch to provide the engineering, procurement and construction management services for the project. The San Martin project was in full-scale commercial operation approximately 14 months after the receipt of Board approval, and by July 2001 the San Martin project was operating at approximately 150% of its feasibility design capacity."

Jan 1, 2002

By H. Verakis, M. J. Sapko

The Pittsburgh Research Laboratory (PRL)1 of the National Institute for Occupational Safety and Health (NIOSH) in collaboration with the Mine Safety and Health Administration (MSHA) Technical Support Center has devised a prototype hand-held instrument which can provide a direct assessment of the potential explosibility of a coal and rock dust mixture. Current Federal regulations require that rock dust be applied in all underground areas of a coal mine to mitigate the propagation of a coal dust explosion. To determine compliance with the Federal regulation, mine inspectors collect dust samples from sections of underground coal mines for an MSHA laboratory analysis of incombustible content. However, the laboratory analysis may not be completed for more than a week or two, during which time the mine area from which samples are taken may be inadequately protected. The operation of the Coal Dust Explosibility Meter (CDEM) is based on the difference in optical reflectance between light rock dust and dark coal dust. For a given coal volatility, the optical reflectance of such mixtures is relatively constant at the limit of explosibility, independent of the coal dust particle size. The CDEM is not intended to replace the current MSHA laboratory analysis of coal mine dust samples for incombustible content, but to serve as a supplemental device for enhancing mine safety through improved rock dusting practices.

Jan 1, 2006

By Henry S. McDevitt

External Shock Mitigation (ESM) is being studied as a possible means of retrofitting existing buried structures to provide additional protection from ground shock. As part of this study, two tests were conducted on four ESM models and a control structure. The test articles were placed at a carrnon distance and subjected to the ground motions created by a buried explosive charge consisting of 2,ODO pounds of nitranethane (NM). Adequate instrumentation data were obtained to assess the response of the four ESM models. The assessment relied heavily on direct comparison of horizontal motions measured in the models, with similar measurements in the control structure. From the tests, it was observed that peak accelerations were reduced by a factor of 5 by the ESM. However, the particle velocities and displacements were not significantly affected by theEIS.

Jan 1, 1997

By W. M. Dressel

This Bureau of Mines report describes a shaft closure demonstration project in which 11 inverted pyramid-shaped plugs were used to plug abandoned open mine shafts in Galena, KS, The inverted pyramid-shaped forms, fabricated from steelplate, were designed so that the inverted base would be larger, by 4 ft on a side, than the approximate size of the shaft opening at the surface residuum-solid rock interface. After the surface openings of the shafts were trimmed with a backhoe, the steel forms, complete with reinforcing, were lowered into the openings and filled with concrete; the remaining portions of the openings above the plugs were backfilled to slightly above the surrounding surface level with waste rock and soil. Location and elevation monuments were installed for long-tern evaluation of the success of the project.

Jan 1, 1985

The gold concentration profiles which develop inside the activated carbon particles during the adsorption process were measured, so as to obtain additional direct proof of intra-particle mass transfer rate-control and to determine how individual carbon particles in a population vary in their gold uptake behaviour. The observed gold concentration profiles inside the activated carbon particles were typical of situations where an intra-particle mass transfer mechanism is rate-controlling. Gold di-cyanide penetrated the carbon particles with a wave-like front until it was uniformly distributed throughout the particle. This corresponds with the profiles predicted by the film and surface diffusion model. However, the rate with which gold di-cyanide was transported inside the individual carbon particles varied within the population of carbon particles. This variation was characterized by a lognormal distribution in surface diffusivity. Because the estimated variances of these surface diffusivity distributions were small, the dynamic adsorption behaviour of the carbons used in the present study did not deviate significantly from that predicted by a model based on film mass transfer and a single surface diffusivity. Van Deventer (1984, 1985 and 1986a) reported data that could not be adequately described by a model based on film mass transfer and a single surface diffusivity. In this study a model based on film mass transfer and a wide lognormal distribution of surface diffusivity values was applied to his data. It was shown that a population of carbon particles with a wide distribution in surface diffusivity values could offer an alternative explanation to the mechanism proposed by Van Deventer which was based on film mass transfer, with partitioning of the carbon into micro- and macropores with surface diffusion in the macropores and slow mass transfer into the micropores.

Jan 1, 1997

By Donna L. Anderson

The first section of this U.S. Bureau of Mines report includes a discussion of the navigational tasks performed by operators of mobile mining equipment, with the focus on the navigational information and guidance techniques required by continuous mining machine operators. Some previous research and attempts in remote and autonomous navigation of continuous mining machines are mentioned. Issues of research in autonomous navigation of various other mobile robots are presented, with attention focused on their applicability to a continuous mining machine navigating in the mining environment. Conclusions are stated on methods of automating the navigational tasks of a continuous mining machine, and a decision to concentrate initial attempts on the tasks of autonomous face navigation is defended. The second section of this report includes a presentation of the Bureau's proposed solution for autonomous face navigation of a continuous mining machine, which includes the employment of a mobile roof support as a reference for guidance in the face area, and a navigational guidance system for the continuous mining machine.

Jan 1, 1989

By Val E. Payne

Issues between resource utilization and resource preservation often develop in connection with coal mining. One such conflict exists in eastern Utah where PacifiCorp and Energy West Mining Company are working with State and Federal agencies to address the resource recovery/resource preservation dispute. The effects of underground longwall coal mining on golden eagle (Aquila chrysaetos) cliff nesting sites have been studied at the Cottonwood Mine since 1986. Subsidence, escarpment spalling, and the nesting activities of the local eagle population were monitored.

Jan 1, 1986

By B. Gigas, M. Preston, M. Giralico

Optimized mixer settler designs will now handle total flows of over 6,000 m3/hr.Computational Fluid Dynamics (CFD) is a timely and predictable tool for design development. Lightnin has the capability of using numerical analysis methodology to evaluate flow patterns and phase separation. CFD can show performance differences between changes, in mix tanks, in settler geometry, and in liquid depth, against variable flow rates. Understanding the differences allows the development of optimized designs. This paper focuses on the major design components of the mixer settler and how technological advances will lead to further improvements, when designing for today’s largest flow plants.

Jan 1, 2004

By S. Kelebek, E. Yalcin

"Two composite samples of a gold-bearing ore from North Western Quebec (Barry Township) were tested to assess their grindability, recovery by flotation and Knelson concentrator as well as extraction using cyanidation.Work index values (BWi) for two composites were found to be 10.4 and 11.0 kWh/tonne, respectively. Flotation tests involved feed samples for which the particle size ranged from a P80 value of 205 ?m to 53 ?m, which resulted in gold recoveries of 91.8% to 95.8% (at gold grades of 130 to 140 g/tonne). Cyanidation tests indicated gold extraction levels ranging from 94.2 to 97.5%. Higher, recoveries were obtained at finer grind sizes and higher cyanide strengths. However, the grind size had a bigger impact on gold leaching. Gold grade and recoveries obtained with the Knelson concentrator device were lower than those obtained by flotation. Mass recoveries to concentrate products strongly depended on the fluidization pressure used. High gold recoveries can be obtained generally at low water pressures of 3 to 4 psi. Higher water pressures produced more selectivity at the expense of higher gold losses.It can be concluded that the gold ore samples tested have good characteristics due to moderate levels of energy requirement, high gold recoveries and extraction rates attainable.INTRODUCTIONBench scale testing of ore samples is an important step in the long series of metallurgical and economic studies involved in bringing new ore bodies into production (Coleman, 1980). Through a laboratory testing program, the behaviour of an ore in a particular process on a larger scale can be established. In an exploratory manner, this testing can be helpful for classification of ores in terms of “good ore” or “problematic ore” by providing preliminary information on recoverability of target minerals. Potential problems if any can be assessed by further investigation of products (e.g., middlings) obtained as a result of testing. A detailed bench scale experimental program in the metallurgical laboratory can also provide the background work for flowsheet development. Depending on the simplicity or complexity of the ore to be tested and type of details required from a testing program, the amount of samples required in the mineral processing laboratory can vary from several kg to more than one hundred kg depending on how detailed the metallurgical testing program is."

Jan 1, 2008