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By Judson G. Brown

In the May, 1969 issue of Mining Engineering the Editorial Director, John V. Beall, described the Japanese Onahama Copper Smelter and Refinery as follows: "On the shore of the Pacific, 120 miles north of Tokyo, is the world's most modern copper smelter and refinery.? One of the improvements that has been made at the Onahama Refinery is the quality of the electrolyte in the copper refinery electrolytic cells. This has been accomplished by reducing the concentration of slimes in the cells between the electrodes. In a December 19, 1966 review in Chemical Engineering magazine reference was made to some tests in Sweden as follows: ?However, at 1,000 amps/sq.M., satisfactory cathodes could be prepared, provided electrolyte flow past the anode and cathode was at least 3 to 4 meters per minute, and the slime content was not allowed to exceed 20 to 30 mg. per liter. By dropping the current to 500 amps with the same electrolyte velocity, the slime content could grow to 50 mg. per liter (50 ppm) without causing occlusion at the cathode." From this data it appears that the production capacity of copper refining electrolytic cells can be significantly increased. In order to do this the concentration of suspended contaminating slimes in the electrolyte solution is reduced by filtration. The electrolyte in-between the active electrodes must be purged with higher velocities to maintain a high concentration of the desirable copper ion in the liquid film adjacent to the cathode and the sulfate ion in the liquid film at the anode. This higher velocity also carries away from the cathode the undesirable impurities released from the anode as they are released into the electrolyte as filterable solids.

Jan 1, 1970

In April 2012, work started on one of the most ambitious construction projects of Austria?s ÖBB-Infrastruktur AG ? the New Semmering Base Tunnel. Scheduled for completion in 2024, the 27.3 km (17 mile) tunnel through the Semmering range will cut the journey time on the south railway connecting Lower Austria and Styria. Before con-struction can begin at the entrance portal and tunnel bores, the work concentrates on the above ground sections with the clearance and excavation of the entrance ramp site. The slope is currently being excavated by the Baubeteiligungsge-sellschaft m.b.H. BBG-GRAZ. The cut face is shored up with shotcrete and permanent self-drilling anchors produced by Minova MAI, an economical bolting solution for softer rock formations. After completing the surface construction work, the twin-bore, single-track tunnel will be cut through the Semmering by conventional and continuous excavation beginning in 2015. Once completed, the New Semmering Base Tunnel will be one of the longest rail tunnels in Austria. It will act as a vital link on the route crossing Europe?s heartland from Northern Germany to Italy, which currently has to climb the steep Semmering pass between Gloggnitz and Mürzzuschlag on a historic mountain railway recognized as one of the UNESCO World Heritage sites. The old route imposes considerable limitations on heavy freight trans-port, and passenger trains have to slow down to a speed of around 50 kph (31 mph). The New Semmering Base Tunnel will bypass this bottleneck and cut 30 minutes off the journey time between Vienna and Graz. It represents a particular advantage for freight traffic, since the new route?s minimal incline of 8.4 percent removes all obstacles for even heavy freight trains.

Jan 1, 2013

By H. M. Ray

The discovery of the New Lead Belt in the mid-'50s began a search for mill design criteria that is continuously updated. The opportunity to design, construct, and operate four new mills in the span of 20 years provided fertile areas for new concepts. The central theme for design parameters encompassed simplicity, functional, and economic consideration. Ore characteristics for each plant remained relatively constant, providing stable criteria for grinding circuits. Bond index nominally 10-12. Flotation circuit parameters were based upon power application with 10-20% excess capacity built-in to protect recovery. Newer equipment exhibits greater power application efficiency lowering horsepower requirements per ton. Instrumentation was installed to stabilize circuits, protect equipment, and improve products. With ever increasing requirements of higher quality products, environmental considerations, and operating cost pressures, the upgrading of operating procedures is in a constant state of flux. Installation of more efficient equipment, chemical processing, or any other technique would be considered as feasible. Current practice is for St. Joe to design and engineer in-house its own plant design. The exception being detailing of structural steel. It is felt that familiarity with past design criteria serves as a valuable foundation to incorporate changes. Also, direct contact with operator provides specific data, and feedback for constructive criticism that is utilized for defining and correcting problems. The results are in reality an operator's plant with the benefit of advancing technology that meets the demands for improved products without sacrificing the economies of throughput or recovery.

Jan 1, 1977

By A. Moergeli, Philip Sander, John Reilly

"SUMMARY While the basic elements of risk management, including probability, consequences, risk registers, mitigation measures, etc., are now well understood, the process to include correlation, dependencies and linkage of risks and risk scenarios is less well defined and not well understood. To perform accurate and complete risk analysis and risk management, it is necessary to include correlation, dependencies and linkage between risk events, as well as risks that may occur multiple times. In this way, owners and contractors can more accurately determine risk-based costs, risk impacts and risk mitigation strategies. This paper will outline methods to deal with correlation, dependencies and linkage and will consider risks that may occur multiple times. Practical result comparisons – with or without these elements – will be presented. INTRODUCTION We believe the reader is familiar with basic concepts of risk, risk management and mitigation and the use of probabilistic cost-risk processes versus deterministic ones (Reilly et al. 2015; Sander et al. 2015). The probabilistic approach, compared to the simpler and more common deterministic approach (unit prices times unit costs plus a contingency), offers more useful information with respect to the range of probable cost as well as cost “drivers” and better quantifies the effects of risks, opportunities and variability – which improves understanding, leading to a better potential for profit (or loss) for contractors and added value for owners. In this context, a valid and sufficient quantification of correlation, dependencies and linkage of risk events, plus the impact of risks that may occur multiple times, is essential. Components of Cost Estimates – Base Cost, Risks and Other Uncertainties The components of cost that need to be correctly addressed in an estimate include (Moergeli et al. 2015): •,Base costs – the costs that will result if “all goes according to plan” (Reilly 2004) •,Risk costs – the resulting costs of threat and opportunity events, if they should occur •,Escalation costs – costs resulting from normally expected inflation with variability •,Other uncertain costs – costs that result from other events, normally external to the project team’s control, which may include unanticipated events, politically related changes and “black swan” events (Talib 2007)"

Jan 1, 2016

By Wallace Macgregor

The direct investment role of Middle Eastern oil producing countries in future world-wide mineral development probably will be a limited one for the next five years. Their needs and their longer range economic objectives substantially preclude any such risk taking ventures. There is, of course, the possibility of political in- vestment. One hears many rumors and doomsday calculations of what the Arabs might do with the rising accumulation of surplus funds. Up to now, this kind of investment has been more in rhetoric than in money. For the most part, oil producing countries of the Middle East have been, and will be, investing surplus funds with strong emphasis on the preservation of capital. They will seek security first and yield second just like any other prudent investor. In several respects, this is regrettable. A direct infusion of risk capital into mineral development, especially in the Third World countries, is a constructive way of enhancing their earning power which many desperately need just to stave off starvation. It would also be a good way of eliminating material shortages in the industrialized world. Most important of all, it would help to ultimately reduce inflation without imposing the hardship of recession. So why isn't it done?

Jan 1, 1975

By Ian M. Loomis, Keith G. Wallace

The Waste Isolation Pilot Plant (WIPP) is a U.S. Department of Energy research and development facility designed to demonstrate the permanent, safe disposal of U.S. defense-generated transuranic waste. The waste storage horizon is 655 m (2150 ft) below surface in bedded salt. To date the WIPP project has not emplaced any waste. There are three intake shafts used to supply air to the underground. All air is exhausted though a single return shaft. The total design airflow during normal operations is 200 m3/s (424,000 cfm). The ventilation system is designed to provide separate air splits to construction, experimental, and storage activities. Separation is achieved by isolating the storage circuit from the construction or experimental circuits with bulkheads. Any air leakage must be towards the storage area of the facility. Field studies have shown that the pressure differential necessary to maintain the correct leakage direction is susceptible to the effects of natural ventilation; therefore, extensive studies and analyses have been conducted to quantity the natural ventilation effects on the WIPP underground airflow system. A component of this work is a monitoring system designed to measure the air properties necessary for calculation of the natural ventilation pressure (NVP). This monitoring system consists of measuring dry bulb temperature, relative humidity, and barometric pressure at strategic locations on surface and underground. The psychrometric parameters of the air are measured every fifteen minutes. From these data, trends can be determined showing the impact of NVP on the ventilation system during diurnal variations in surface climate. Both summer and winter conditions have been studied. To the author's knowledge this is the first reported instance of automatic and continuous production of time and temperature variant NVPs. This paper describes the results of the initial monitoring study. INTRODUCTION The ventilation system at the Waste Isolation Pilot Plant (WIPP) in Carlsbad, New Mexico, is designed to perform two distinct functions. First, it supports normal mine ventilation requirements complying with all state and federal mine regulations. Second, the system is designed to prevent an uncontrolled release of radioactive contaminants from the storage and transportation areas of the facility. Although a nuclear radiation release in the facility is considered unlikely, many special features are implemented in the ventilation system to prevent the possible spread of contamination. The facility is constructed with the waste transportation and storage areas separated from the mining and non-radioactive experimental areas. The ventilation system is designed such that air leakage is from the mining and experimental areas to the storage areas. Furthermore, radiation detectors are located throughout the storage and waste transportation areas underground and an exhaust filtration building is installed on surface to prevent the possible release of radiation to the environment. For over two years the underground ventilation system has been rigorously tested and balanced. It was during this period that the adverse effects of NVP were noticed and subsequently quantified. From extensive field studies and computer models, several mitigating features were designed and constructed and special operational procedures were implemented to control the impacts of NVP. To quantify more accurately the NVP at the WIPP, a continuous monitoring system was installed. This monitoring system consists of measuring dry bulb temperature, relative humidity, and barometric pressure every fifteen minutes at strategic locations on surface and underground. From this psychrometric data, the NVP is calculated. Fan operating pressures and flows and strategic differential pressures are recorded from the site Continuous Monitoring System (CMS). The monitoring system provides a means of evaluating how the ventilation system behaves in regard to climatic conditions and to judge the efficacy of the mitigating features and operational procedures. To the author's knowledge, continuous calculation of NVP as a function of time and surface temperature has not been previously reported. Overview of the Waste Isolation Pilot Plant The U.S. Department of Energy determined that the plastic nature of bedded salt may provide the best solution to isolate transuranic (TRU) waste from the biosphere. Initial evaluations at the WIPP site began in 1974. In 1979, the United States Congress enacted Public Law 96-164 for the construction and development of the WIPP project. The mission of the WIPP is to demonstrate the safe, long-term disposal of TRU waste generated by the national defense programs of the United States. TRU waste is classified as a low to medium level waste. The waste is stored in drums and does not produce significant heat (not greater than 1 W per drum). The WIPP site is located approximately 47 km (29 miles) east of Carlsbad, New Mexico in the Chihuahuan Desert. The repository is located in the 630 m (2000 ft) thick Salado Formation. This Permian Basin salt deposit is about 225 million years old and appears to have been minimally disturbed by earthquake, faulting, and ground water activity since it was deposited. The underground facility is 660 m

Jan 1, 1993

By EDER DOMINGOS OLIVEIRA, Leandro Viana Teixeira, Carlos Antonio Morais, Ruberlan Gomes Silva

Special attention must be considered in the production of high-grade rare earth products, such as mixed rare earth oxalates or carbonates. In the main minerals used industrially, the rare earth elements (REEs) are finely associated with impurities like calcium (Ca), magnesium (Mg), manganese (Mn), iron (Fe), aluminum (Al), thorium (Th), uranium (U) and phosphorus (P). Most of these impurities must be removed to avoid losses of rare earth oxides (REOs) as well as to prevent product quality degradation and low operational performance in the downstream steps of solvent extraction or ion exchange. The present study aims at investigating the conditions required to precipitate REEs, either as rare earth oxalates or carbonates, from purified rare earth sulfuric liquor with low Al3+ and UO22+ concentrations and very high Ca2+, Mg2+, Mn2+, and SO42− impurity contents.

By Anthony Peach, Lok Home

Introduction Raise boring is the most accepted form of mechanized hard rock boring in the mining industry. It appeared logical to take this mechanization one step further by introducing computers. Atlas Copco Jarva has produced a series of raise boring models that use an integrated computer. The company decided to use electronics and computerization, not for marketing purposes, but to make its equipment more cost-effective. Basis of Cost-Effective Design From the manufacturer's standpoint, it is possible for the equipment owner to reduce the cost of putting in raises by: • Replacing existing components with less expensive components that produce the same results; • Replacing existing components with more expensive components that make the equipment more productive; • Mechanizing equipment to reduce associated labor costs; and • Combining the above. Analysis of a standard raise boring machine (RBM) system showed that little could be done with less expensive components. It appeared, however, that the RBM could be more productive by transmitting more horsepower through the expensive drill string, while being precisely controlled by computers. An RBM system includes a basic machine, drill pipe, accessories, reamer, and cutters. The approximate percentage cost of various components on a standard system capable of boring 300 m (985 ft) long and 3-m-diam (10-ft-diam) aises in medium to hard rock is shown in Table 1. Also shown is the increased cost above standard of the Jarva computerized machine, and the productivity of both. Increased Productivity Penetration is important during the reaming cycle for more productive raise boring. This is possible by increasing the cutter load with constant rpm or increasing the rpm with constant cutter load. To increase thrust and maintain rpm requires increased capacity in the cylinders, drive train, main thrust bearings, drill string, electrical motors, and power units. To increase rpm and maintain cutter load requires only increased capacity in the electrical motors and power units. This is possible because the torque requirement remains constant for a constant thrust load. Only the horsepower increases, proportional to rpm. Since cutter costs are a big factor in raise boring, changes in machine performance must be analyzed to assess the effect on cutter performance. With a standard or typical carbide cutter, as used on raise boring machines, the effects of increased thrust or rpm are shown in Table 2. The assumption is made that the base data is the current rpm and thrust range where the cutters are now operated. It is also assumed one variable is held constant while the other increases. The result of this comparison, approximately, is that a 50% penetration increase can be achieved with little or no increase in cutter cost if rpm is increased 50% and cutter load is maintained constant. A similar 50% penetration increase can be achieved with a 45% increase in cutter cost, if the cutter load is increased by 20% and maintained constant. From an equipment standpoint, it is significantly less expensive to increase rpm 50% than it is to in-

Jan 7, 1984

By J. Kretschmann, K. van de Loo, J. Brune

In 2018, the German Federal government decided to phase-out the energy production using coal-fired power plants and to terminate lignite mining completely by 2038 at the latest. This decision will impact approximately 60,000 jobs. It will have an enormous impact on the socioeconomic development especially in all German lignite mining regions. To avoid economic and political friction, it is of utmost importance to achieve a sustainable transition towards a post-mining era and to offer residents in the mining districts perspectives for a good future that include adequate job opportunities. In this context, the German government is providing massive structural aids early on. As previous closure experiences from the German hard coal mining industry have shown, it takes at least a generation to overcome the effects of a strategic closing decision of this magnitude. Therefore, the planned closure process appears to be a long time at first glance. In fact, however, it is not.

Mar 2, 2022

By V. Svalbonas

In the establishment of a useful failure criteria for complicated, fabricated structures, two basic areas of knowledge must be evaluated: 1. The accuracy of the applied stress analysis must be known in comparison with actual stresses encountered during mill operation. 2. The metallurgical fracture properties of the basic materials must be established with reference to non-destructive examination (NDE) methods to be used during fabrication. Both of the above can only be evaluated by use of full scale tests on the structures, and/or components, of interest. This paper describes such tests and comparisons as applied to several large mill installations. In addition, weldment component fatigue tests arid flawed casting strain gauge tests are also discussed. The combination of such test results allows for the formulation of failure criteria directly applicable to the fabrication and examination procedures followed in grinding mill structure manufacture.

Jan 1, 1982

By Frank E. McCall, Michael A. Trevits, Fred Garcia

The U.S. Bureau of Mines investigated the influence of atmospheric pressure changes on methane gas migration through mine seals at a mine site located in the Pittsburgh Coalbed. The mine gained access to a coal reserve through part of an abandoned mine and constructed nine seals to isolate the extensive old workings from the active mine area. Underground problems were experienced when atmospheric pressure fell, causing methane gas to migrate around the seals and into the active workings. During mining operations, methane gas levels exceeded legal limits and coal production was halted until the ventilation system could be improved. When mining resumed with increased air flow, methane gas concentrations occasionally exceeded the legal limits and production had to be halted until the methane level fell within the mandated limit. To assist the ventilation system, a pressure relief borehole located in the abandoned workings near the mine seals was proposed. Preliminary estimates by a gob gas simulator (computer model) suggested that a 0.76 m (2.5 ft) diameter pressure relief borehole with an exhaust fan would be necessary to remove enough methane from the abandoned area so that the ventilation system could dilute the gas in the active workings. However, by monitoring methane gas emissions and seal pressure, during periods of low atmospheric pressure, the amount of methane gas that migrated into the active mine workings was calculated. Researchers then determined that a relief borehole, 20.3 cm (8-in) with an exhaust fan could remove at least twice the maximum measured volume of migrating methane gas. Because gas concentrations in the abandoned workings could potentially reach explosive limits, it was proposed that the mine eliminate the exhaust fan. Installation of the recommended borehole and enlarging two other ventilation boreholes located in the abandoned area reduced methane gas leakage through the seals by at least 63%.

Jan 1, 1995

By K. F. Unrug

The identification of the major subsidence areas in the Western Kentucky Coal Field has been made to distinguish the subsidence phenomena on the basis of geographical location Further, this identification process is based upon selected critical geological, topographical, and mining features in the coal fields. The proposed identification of the regions is derived from a comparison of the subsidence potential in a particular area. The most likely severe subsidence areas are compared to those with the probable low subsidence severity. The combination of certain geological and mining parameters involved allows for the derivation of a classification of the subsidence potential. It is recommended that further site specific studies should be performed on this area.

Jan 1, 1986

By Albert J. Kritscher

The Similkameen Copper Project located near Princeton, British Columbia, is operated by the Similkameen Mining Company Limited, a wholly-owned subsidiary of Newmont Mining Company. The orebodies for this project are located on both sides of the Similkameen River for which the project is named. The project involves the processing of an average of 15,000 STPD of andesitic ore, mineralized largely with Chalcopyrite, at an overall plant availability rating of 90 percent. Project life is nominally 15 years. Design for the plant and its ancillary facilities was undertaken by Bechtel Corporation with procurement and construction management by Canadian Bechtel Limited. Construction began in June 1970 and first ore was introduced into process in March 1972. This paper concerns itself only with the project tailing system. The processing plant is located on a bench of glacial stream gravels which overlooks the river canyon. This site represented the only relatively flat area of sufficient size to accomodate processing facilities near to the ore- bodies. Reference is made to Figs. 1 and 2 showing the relationship of project features in plan and profile.

Jan 1, 1973

By Ryan Marsters, Adam Pring

The Rawah Ditch is a mountainous water supply diversion which supplies Larimer County, Colorado with water since 1903. The ditch includes two historic tunnels excavated by drill and blast through a gneissic rock buttress. Both rock tunnels were failing with annual convergence. After a snowshoe-accessed eld investigation, nite element modeling, and an alternatives analysis, a diameter DE pipe was inserted within each tunnel and the annulus lled. The proect was implemented in an Alternative Delivery contract lasting ve months from eld investigation through procurement and construction.

Jun 23, 2024

By V. O. Tenorio

The implementation of autonomous technologies for production in surface mines demands changes in the existing monitoring and control systems. The present study deals with the concepts involved in the development of a decision support system (DSS) for the supervision of a combined fleet of manned and unmanned equipment operating in a surface mine. The project was carried out as part of an autonomous mining program that lasted from early 2006 until the end of 2008. The objective of the DSS was to achieve short-term planning goals while maintaining safe working conditions. Supervisory tasks become more complex when several autonomous vehicles operate simultaneously alongside manned equipment. The operation center where the DSS was installed allowed autonomous vehicle operations to be controlled while tracking technology reliability experiments performed on control display interfaces and interaction provided design parameters for more complex supervisory systems for autonomous mines. Mining Engineering, 2011, vol. 63, no. 11, pp. 80-86. Official publication of the Society for mining, metallurgy and exploration, Inc.

Jan 1, 2011

By Thomas E. Ban

D-LM at Mobile The qualified success of iron ore pelletizing processes has influenced considerations for production of highly beneficiated fur¬nace charges. Such beneficiation would necessarily involve some forms of chemical and perhaps thermal conversion for production of prereduced pellets, preheated pellets, precalcined pellets, and perhaps pellets which contain all of the above features as preheated, prereduced, precalcined products. This type of furnace burden will be adapted within a new ironmaking process to be activated commer¬cially during the latter part of 196$ in Mobile, Alabama. This process will integrate a new pelletizing system with an electric smelting furnace and the pellets will be comprised of a composite charge blended from metallurgical proportions of iron ore, coal, and limestone. The plant as designed and constructed by McDowell¬-Wellman Engineering Company will feature the D-LM process and will be owned by McWane Cast Iron Pipe Company. It is significant to

Jan 1, 1968

By Russell L. Cook

Stringent environmental regulations, which have limited the use of sludge ponds, coupled with the economic incentive to clean more 'coal or to add fine coal cleaning additions to existing preparation plants have increased the use of static thickeners in preparation plants. The Lamella Gravity Settler, sometimes de signated Lamella Thickener, is a shallow depth sedimentation device which has been applied in a variety of industrial process and wastewater control projects in place of the conventional raked thickeners. This paper presents the theory and design of the La-mella Thickener, as well as describing the operating results from several full scale installations in a variety of Appalachian preparation plants.

Jan 1, 1977

By Yi Yang, CHENGLONG XU, HAORAN LI, YALI FENG, JINRONG JU

Steel slag is an industrial byproduct of steelmaking that is mainly composed of calcium, iron, silicon and magnesium. In addition, depending on the different raw materials entering the furnace, steel slag contains a certain amount of vanadium that is the main source of vanadium production, accounting for 69 percent of the species of the total vanadium raw material [1]. From experience, the production of one ton of steel will generate 1.0 to 1.5 tons of steel slag [2]. However, the utilization efficiency of steel slag is less than 30 percent, and a large amount of steel slag is identified as waste and stacked in tailings. The random stacking of steel slag not only wastes large amounts of limited steel and land resources but also exerts pressure on the environment [3], making it imperative to research the effective utilization of steel slag and recycling of metal resources.

By Corey Vaughan

Unplanned shutdowns from abrasive wear part failure in crushers, chutes, and slurry pipe assets can cost millions in lost production and reactive maintenance. 2Censor patented sensor technology enables real time abrasive wear monitoring of mineral processing equipment, turning passive assets into smart, data driven components. Wireless sensors embedded in liners and pipework transmit wear data live to operators, allowing for predictive maintenance, safer scheduling, and optimized asset life. This paper will present global case studies showing reductions in downtime, increased throughput, and improved maintenance accuracy. The system is ready to retrofit, neutral to original equipment manufacturers, and proven across more than twelve countries in abrasive wear liners and slurry pipe applications.

Feb 22, 2026

By Ronney Rodrigues Silva, Renata Mendonca, Gabi Knesel, Cathrine Monyake

Locus Mining is working side-by-side with a prestigious iron ore company to evaluate the addition of Locus ESG-friendly green flotation reagents with the primary goal of improving recovery and grade. In this paper, we will focus on the cationic reverse flotation application. The most “established industry” reagents for cationic reverse flotation are amine as the collector, starch as the depressant, and in some cases frothers are also used (among them MIBC, pine oil, others). Here, we evaluate the synergies of different classes of eco-friendly biosurfactants and industry-standard reagents during the cationic reverse flotation method. Exploratory research was done first with an analog sample under different pHs, eight different biosurfactants with starch and no-starch, and a customized DOE was used to perform 145 microflotation tests. The results show Separation Efficiency from 20% (baseline) to 50% (biosurfactant), and Selectivity from 3.27 (baseline) to 5.67 (biosurfactant). Optimized result conditions were then applied to the iron ore samples received from our client to perform flotation tests on a Denver Lab cell. Similar results were obtained by improving Separation Efficiency and Selectivity, which corroborate with the previous work.

Feb 1, 2025