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By Hyunsuk Yoon, Kiho Lee, Juhyng Lee, Younghoon Jung, Junboum Park

"The environmental double pile method is presented as a device to improve the engineering properties and to clean up contamination of low-permeability soil. This method is one of the novel technologies based on the concept of one step process. It can be applied to low permeable contaminated ground for site reuse. It uses piles to improve drainage, contaminant remediation, and bearing capacity of the ground. To evaluate the on-site applicability of this technology, drainage and strength properties of the environmental double pile were assessed by a series of experiments and numerical analysis. Environmental double pile was found to be a feasible alternative method to improve contaminated soft ground.Korea is a peninsula with many coastal industrial zones. These zones are located in regions mostly underlain by soft ground with low permeability and adjacent to industrial areas that can be contaminated. Therefore, a new region-specific remediation method is required to achieve environmentally sustainable development. This research introduces the Environmental Double Pile (hereinafter, refer to as EDP) for the lowpermeability contaminated ground and focused on both contaminant remediation and soft ground improvement. Basically, the EDP is quite similar to sand compaction pile (SCP). The SCP has been studied extensively to improve soft ground (Braja 1999; Hansbo 1994; Madhav and others 1978; Taylor 1948). But unlike SCP, EDP is filled with oyster shells instead of sand and an inner pile is inserted in the center of this oyster shell filled-zone. Therefore, it is a double pile consisting of the oyster shell pile and the inner pile, as depicted in Fig. 1."

Jan 1, 2005

By A. J. Kwitowski

Teleoperation is a technology that can provide significant health and safety improvements in mining, by relocating machine operators hundreds of meters away from the face area. The U. S. Bureau of Mines (USBM) has recently developed a teleoperation system for continuous mining and haulage equipment. This system features near-real-time closed-loop control. A prototype system was developed and demonstrated on the surface. This system could be used in thin-seam applications down to 914 mm. Details are provided on the developed teleoperation system, results of testing, and expected, future applications of this technology for improved safety.

Jan 1, 1994

By C. Acuña

The case is presented that the key role of frother is control of bubble size in the pulp zone. Compared to water alone, the addition of frother produces a narrower distribution and finer bubble size. An empirical model is presented for bubble size as a function of frother type using a normalized concentration. The model provides a benchmark for assessing operations. There is no agreed upon mechanism of how frothers act to reduce bubble size. Prevention of coalescence is a common explanation and this action is illustrated. The case against the 'coalescence' model alone is presented and a breakup mechanism is introduced based on pilot cell and single bubble studies. Phenomena associated with bubble shape, velocity and surface flows are used to illustrate the force associated with surface tension gradients. Breakup mechanisms resulting from this force are proposed. The concept can be extended to high salt concentrations which also promote small bubbles.

Jan 1, 2007

Mount Isa Mines Limited (MIM) and the Commonwealth Scientific and Industrial Research Organization (CSIRO) have, over the past 15 years, jointly developed the Isasmelt process. This process is based on the use of the Sirosmelt top-entry, submerged combustion lance, developed by the CSIRO in 1973. While the Isasmelt technology was first applied to lead smelting, it has more recently been adapted to smelt copper concentrate. A 15 t/h demonstration Copper Isasmelt plant was commissioned in MIM's Mount Isa copper smelter in April 1987. The success of the Copper Isasmelt demonstration plant, which smelted over 532,000 metric tons of copper concentrate, has led to the construction of two full-scale furnaces: a 104 t/h furnace in the Mount Isa copper smelter, and a 585,000 t/y (650,000 short t/y) furnace at the Cyprus Miami Mining Corporation smelter at Miami, Arizona. The commissioning of these furnaces commenced in August and June 1992, respectively. The MIM Copper Isasmelt furnace will raise the Mount Isa copper smelter's capacity to 265,000 t/y of copper. The plant includes several innovative features, including: Andritz pressure filters, a rotary holding furnace, and an Ahlstrom flux-flow boiler.

Jan 1, 1993

By Edward P. Hagarty

The Hazardous and Solid Waste Amendments (HSWA) of 1984 added Subtitle I to the Resource Conservation and Recovery Act (RCRA), authorizing the Environmental Protection Agency (EPA) to develop and implement a new regulatory program for Underground Storage Tanks (USTs) containing petroleum and other regulated substances. Technical standards required for release detection, prevention, and correction as necessary to protect human health and the environment were promulgated as described in 53 Federal Register 37082 (September 23, 1988). Virginia State Regulations (VR 680- 13-02) and U.S. Army Regulations require that a Corrective Action Plan and a Site Clearance Report be prepared to explain the details of remediation of any contaminated media. Construction of new buildings is proposed in two different areas at Fort Myer in Arlington, Virginia, where USTs containing gasoline, diesel and heating oil were located. Tightness testing performed on these USTs in September 1991 indicated that some of the tanks were leaking. Many of the tanks were removed for permanent closure. Initial Abatement (excavation of contaminated soil) was &ed out immediately. A detailed Site Characterization Study which included Hydropunch", field screening using immunoassay, and pilot test - dual phase (water and soil gas) extraction was conducted. Environmental media were analyzed for volatiles, semi-volatiles and metals. A detailed risk analysis (RA) was performed to determine risk-based clean up levels for benzene, toluene, ethylbenzene, xylenes (BTEX); polycyclic aromatic hydrocarbons (PAHs); and methyl-tertiary butyl ether (MTBE). The RA also discussed the presence of lead in the soil. Before constructing any buildings in these contaminated areas, remediation must be conducted in accordance with the State, Federal and other applicable regulations. The remedial alternatives evaluated included Vapor Enhanced Groundwater Extraction, Soil Vacuum Extraction, Soil Washing, Soil Steaming, Active and Passive Ventilation SolidificationlStabilization, Vapor Barrier Construction, and Excavation with Off-site Disposal. This paper discusses: (a) delineation of soil contamination @) risk analysis (c) evaluation of remedial alternatives and selection of the most appropriate technology and (d) consideration of various regulatory issues.

Jan 1, 1994

By R. E. Campbell

Uranium metal of improved purity was prepared by electrorefining commercial magnesium-reduced uranium in a molten sodium chloride-uranium trichloride electrolyte. The best operating conditions for the preparation of refined metal were established as follows: an electrolyte containing 8.7 to 13.3 weight-percent uranium; initial cathode current densities from 300 to 1,500 amp/sq ft; and a molten salt temperature of 860° C. Ingots produced from electrorefined uranium crystals prepared with these operating conditions were substantially free of metallic impurities. The only impurities in the refined and consolidated metal were present in low or undetectable amounts.

Jan 1, 1965

By Eric R. Bauer

This Bureau of Mines publication describes and illustrates the physical signs of excessive loading on mine roof supports, installations, and openings. It is designed to assist mine personnel in recognizing potentially hazardous ground conditions, by emphasizing the preliminary effects of developing unstable ground. Increased worker awareness can be expected to reduce the injuries and fatalities resulting from falls of roof, rib, and face.

Jan 1, 1985

By Kelly J. Driscoll

Impure zinc (98.5%) was electrorefined to high purity zinc (99.995%) using a fused salt electrolyte of molar composition 1: 1 : 1 :2 ZnCI2:KCl:NaCl:LiCl with a current efficiency of about 90% at 723 K. A recessed channel electrorefining cell was developed which achieved excellent mixing of both the metal and the electrolyte and by ensuring a very small anode to cathode spacing the voltage drop across the cell was 0.16 V and at a current density of 7kA m-2. The physical characteristics of the cell were observed using a low temperature model which showed the formation of droplets and rivulets which provided mixing. The application of this approach to the refining of other non-ferrous metals is discussed.

Jan 1, 1992

By P. Cleyle, J. H. Masliyah, R. S. Chow, Z. H. Xu, Z. A. Zhou

Bubble nucleation in water under dynamic conditions was investigated using an autoclave at an air saturation pressure of 7 atm. Agitation during air saturation of water was found to be crucial in enhancing tiny bubble formation. More bubbles nucleated on hydrophobic surfaces at a higher agitation rate, due to cavity formation by the more intense hydrodynamic conditions. Flotation recovery of bitumen from oil sands demonstrated a significant role of bubbles nucleated in water: more than 50-170% increase in bitumen recovery from different oil sands was obtained by using air supersaturated than the regular water.

Jan 1, 2009

By S. Managi, M. C. Williams, N. H. Behling

Particle processing is a key to using solid particles in fuel cell applications. Selectivity with regard to reactivity, impurities, etc. is important feature and the treatment of particle surfaces could greatly impact the performance of direct carbon fuel cells. Solid fuel particles will become increasingly important in the future. Present energy conversion systems for solid fuels are too inefficient. New energy conversion systems for solid fuels with higher energy conversion efficiencies are possible. Fuel cell technology is a key-technology in these new conversion systems. The direct carbon fuel cell (DCFC) operates on carbon particles obtained from a variety of solid fuel feedstocks. The DCFC is the only fuel cell designed to directly oxidize carbon particles in a special anode chamber. The particles are generally graphite structure with high purity. The electrolyte used is the high temperature solid oxide, molten carbonate or hydroxide electrolyte. Since a pure stream of CO2 is produced the stream can easily be sequestered and disposed. Pure carbon dioxide produced as a by-product would also have a market in many industries. A well-defined technology roadmap identifying key research and development (R&D) issues is necessary to provide a framework for the development of these systems and to prevent entrenchment in inherently inefficient technologies. This review paper describes the direct carbon fuel cell and its system, how it works, the developmental status, the characteristics of the carbon particles needed, and the research and development issues for the technology. INTRODUCTION The DCFC has been under development for many years. It was researched as early as 18961), but an intense research and development is necessary to realize its potential. William W Jacques, a US electrical engineer and chemist, described a DCFC in 1896 in US Patent 555511 for a “Method of converting potential energy of carbon into electrical energy”. Jacques used coke electrodes in a molten NaOH electrolyte. Molten carbonate fuel cell (MCFC), solid oxide (SOFC) or hydroxide electrolyte (AFC) technologies can be used as the basis for the DCFC technology. A schematic of the direct carbon fuel cell in the MCFC mode is shown in Figure 1. The molten carbonate fuel cell operates at approximately 650°C (1200°F). The high operating temperature is needed to achievesufficient conductivity of the carbonate electrolyte, yet allow the use of low-cost metal cell components. A benefit associated with this high temperature is that noble metal catalysts are not required for the cell electrochemical oxidation and reduction processes. For the hydrogen reaction the half-cell electrochemical reactions are

Jan 1, 2019

By J. A. C. Ross

Introduction To enlighten those who may be wondering where anyone could find sufficient data to write a paper on underground concrete work, the author would like to explain that, at Copper Mountain, we have found it necessary to line numerous headings with a layer of concrete in order to keep them in a safe and serviceable condition. The majority of these headings are scram drifts and ore-pass raises. This paper will therefore deal, in the main, with the methods of and reasons for placing concrete in these headings. During recent years, radical changes have been made in the methods of mining ore at the Copper Mountain mine. After considerable experimenting, a mining system has been developed making use of diamond drills for primary breaking and transfering such broken ore through scram drifts with slusher hoists. With the advent of scram drifts, it soon became apparent that some substantial means of reinforcement and protection for the scram drifts themselves would be necessary. Since the orebodies in this mine are cut by numerous dykes or faults, and often both, it was anticipated that some means of support would be required where headings necessarily passed through these incompetent zones. Further, as experience was gained, scram drifts were driven into pillars and in close proximity to old workings so as to recover the maximum amount of ore. In such places, the ground is often severely fractured, either as a result of previous mining or from the effect of excessive rock pressures.

Jan 1, 1950

By J. A. Lombardi

"EXECUTIVE SUMMARY The use of membranes for the treatment of Acid-Mine-Drainage (AMD) water has been a 35 year mining industry quest that has only recently produced commercial scale Zero-Liquid-Discharge (ZLD) plants. The process of development of the membrane treatment of AMD has been defined by the water treatment industry’s efforts to control gypsum scaling of the membranes, an artifact of the concentration of calcium and sulfate ions on the concentrate or “brine” side of the membranes. Improved anti-scalants, changes to membrane surface geometry and a lowered permeate flux rate were all part of solving the calcium sulfate (gypsum) scale formation problem. Whether used singly or as part of a multi-stage membrane treatment process, the production of “left over” membrane concentrate or brine, in any volume large or small, was a second barrier to adoption of the method by the mining industry. The two identified “final brine” treatments were a) solar evaporation ponds and b) mechanical evaporators. Brine disposal by solar means is typically site limited to flat terrains or high net evaporation locations. Mechanical evaporation-crystallization is applicable at all sites but, typically, at onerously high ownership and operating costs. Miwatek, a South African water treatment start-up, has entered the mining AMD ZLD marketplace with two new, pilot-scale tested, processes, both of which are predicated on the innovative treatment of a reasonably concentrated AMD and neither of which produces a final brine that requires disposal. In the Miwatek Brine Treatment, MBT, method the membrane brine is caustic pH adjusted and de-calcified precedent to passage through a second membrane plant. The caustic is generated on-site by a lime treatment of the second-membrane concentrate. The first- and second-stage permeates are blended for discharge. The process usually yields no “final brine” for disposal. In the Miwatek Ettringite Treatment, MET, method a low pH first-stage membrane brine is lime treated in two or three steps in the presence of aluminum in a way that metal hydroxide and calcium sulfate solids are formed and purged from the system. Sufficient aluminum is often present in the feed water to, with judicious recycling, enable operation of the lime-aluminum treatment without the purchase of outside aluminum reagent. The first-stage membrane permeate is blended with the lime-aluminum treated membrane concentrate for discharge. The indications are that the method can comfortably meet the low 250 -500 ppm SO4 discharge water quality standards that have most recently been proposed in South America. The process yields no “final brine” that requires disposal. Projected own-operate costs for the MBT and MET systems are less than the estimated costs for all identified alternative treatments."

Jan 1, 2015

Electronic detonators have been in commercial use for a decade, with an excellent safety record. This paper lists known incidents involving electronic detonators. Typical standards required by regulatory bodies for static electricity and electromagnetic fields are reviewed. The performance of some detonators is compared to these standards; in general the minimum standards are easily exceeded. The general resistance of electronic detonators to extraneous electrical energy that can be derived from the body of test results is compared to danger levels for exposure of humans to these energies; it is shown that electronic detonators can safely tolerate higher electrical energies than people can. This comparison includes comparable data for electric detonators, which are shown to be more vulnerable to extraneous electrical energy than people are. Electronic detonators also bring significant safety benefits in blasting due to their testability, two-way communications, reliability, programmability and precision. The links between these attributes and enhanced safety are discussed with examples from actual blasting. Although electronic detonators are usually more vulnerable to extraneous electricity than non-electric initiation systems, the paper shows that the net safety benefit in handling and blasting is in favor of electronic detonators, which are the safest initiation system that has ever been offered to the mining industry.

Jan 1, 2010

By Patricio Berrios, David Barriga, Peter Amelunxen, Gerson Sandoval, Roger Amelunxen

Laboratory test equipment and methods have undergone relatively little change since their introduction in the 1950’s. The Denver sub-A cell is still by far the most commonly used laboratory batch cell, but bottom-driven and instrumented cells are beginning to appear. Test procedures have also changed little over the past 60 years, and most engineers continue to rely on empirical models for predicted plant scale performance from laboratory scale tests. This approach is problematic, because changes in the froth phase characteristics in the lab hamper the reliability and reproducibility of the empirical extrapolation to plant scale. In a previous work, the authors reported on the impact of froth recovery at the laboratory cell, showing that variability in the froth recovery can lead to significant error in the modeled kinetic rate constant unless it is properly accounted for in the scale-up model. In this work, we review the role of hydraulic entrainment in the lab cell, and how variability in particle specific gravity, shape factor, and froth residence time can impact the entrainment recovery.

Jan 1, 2014

By C. J. Walker

The Bureau of Mines undertook a theoretical and laboratory study to determine the feasibility of using ethylene as a tracer for natural gas in underground gas-storage reservoirs. The study indicated that ethylene was a useful gas tracer in underground gas storages. Tracer losses were not excessive. Laboratory tests were conducted at pressures as high as 500 psia in both wet and dry consolidated-sandstone cores, evaluating tracer loss with gas blends containing natural gas with different concentrations of ethylene tracer. Under certain conditions losses were less than 17 percent.

Jan 1, 1966

By Ali Nadir Khan

Depleting copper resources and advancing technologies have challenged industries to develop more viable, adaptable and cost efficient processes using also secondary raw materials in copper production. This study is targeting to that goal by dynamic modelling of flow and heat transfer coupled with chemical kinetics in an industrial scale flash smelting furnace settler using commercial CFD software ANSYS Fluent. First, different physical phenomena occurring inside the settler, for example, settling and separation of the matte/slag phases, and heat transfer between slag/matte phases and settler walls are studied. Secondly, reaction kinetics between matte and slag, and between slag/matte and settler walls, and impurity element distribution will be studied. This would also include phase changes phenomena due to these reactions and the flow of the reaction gases inside the settler. Settling of polydispersed droplets, their coagulation, breakage, and WEEE particle behavior are further targets of the modelling work.

By D. H. Rubisov

The neural networks modelling approach is one of the most elegant black-box type methods to model industrial processes. In this paper, this approach is applied to model the performance of the CEZ zinc electrowinning plant. The model that was built was found to exhibit an excellent predictive ability for voltage and current density. The model was also used to investigate the sensitivity of the process to various key variables such as temperature, current density, zinc and sulphuric acid concentration, etc. Optimal regimes for zinc production were identified from the power consumption standpoint.

Jan 1, 1996

By E. Zucker

In this paper, as in the 1960 CIM paper of the same name, s1gmf1cant new developments in electrical-mechanical mining equipment are briefly described. These include static thyristor-supplied D.C. drives for mine hoists, load-haul-dump systems, process controls with small and medium-size computers, and several other new items of equipment and Concepts. All the new hardware descriptions are given in the context of over-all process integration. This means the actual mechanical linking together of two or more processes and the preliminary step in the development of production-line mining.

Jan 1, 1969

By Fazel G. Jahromi, Ahmad Ghahreman

"Several studies were performed on the atmospheric leaching of copper sulfide minerals in the presence of activated carbon and a new catalyst, AF 5. AF 5 is a carbon based catalyst with similar properties to those of activated carbon however much better mechanical properties. The activated carbon surface chemistry has been investigated in various studies; however the connection of the surface chemistry of activated carbon and AF 5 with the sulfide minerals during the atmospheric leaching process is not well-understood yet. Based on the surface analysis, AF 5 showed higher surface area than activated carbon (AC). Adsorption and oxidation of copper, arsenic and iron ions in the presence of different activated carbon were investigated. Adsorption properties of both catalysts were similar and 18-24% of iron, 12-18% of copper and 10% of arsenic adsorbed on the catalysts surface form 5 g/L Fe(III) and Cu(II) and 2 g/L As(III) at 80°C. In oxidation experiments, both catalysts reduced Fe(III) and Cu(II) ions and re-oxidized the reduced species in the presence of oxygen and oxidized As(III) ions. The addition of oxidizing ions can enhance the oxidation process kinetics and increase the catalytic capability of carbon.INTRODUCTION Hydrometallurgical processes of copper sulfide concentrates are under development and various different methods have been proposed to increase the atmospheric leaching rate of copper sulfide minerals. These methods include using different media, reagents, and catalysts. Among different methods, leaching of the copper sulfide minerals in the chloride media has some advantages over sulfate media. Smaller scale of operation, increased leaching rates, and lower sulfate formation are some of the benefits of the chloride leaching media over other similar media. Moreover, using ferric and cupric ions as oxidants and utilizing activated carbon as a catalyst has been proven to enhance the leaching rate of copper sulfide minerals effectively. Activated carbon (AC) and AF 5 (micro porous carbon based catalyst) are two of the most efficient and practical catalysts in copper sulfide leaching processes. AC can enhance the copper recovery of enargite in chloride media from 69% to 92% after 96 hours of leaching under the similar conditions (Jahromi & Ghahreman, 2016). It has been shown that AC at acidic pH can generate hydrogen peroxide in the presence of oxygen which can leach copper minerals (Ahmumada et al., 2002)."

Jan 1, 2017

By N. M. Soonawala

Detailed regional geophysical and geochemical surveys, ground surveys and drilling were undertaken to follow-up the federal-provincial Uranium Reconnaissance Program (URP) over the 27,OOO-km2 Kasmere-Munroe area in northwestern Manitoba. An analysis of the URP data showed a fair correlation between the regional airborne radiometric results and lake-bottom geochemical results, both of which also correlated with the regional geology. More detailed surveys defined anomalies with greater precision within the broad zones outlined by the URP. The ground follow-up indicated that URP anomalies can be caused by varying degrees of uranium concentration in the rocks. Mineralization of interest was found in leucogranites at several locations within the survey area. Anomalous uranium concentrations were also found in coarse pegmatites and Hudsonian granitic intrusions. It can be concluded that large-scale regional surveys can be followed up in relatively short periods of time to yield meaningful results if a properly planned exploration sequence is employed, each stage of which successively narrows the area of interest.

Jan 1, 1979