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By W. H. Jang

Recent research has demonstrated the utility of the FTIRIIRS adsorption density equation for in-situ study of surfactant adsorption phenomena at the surfaces of reactive internal reflection elements (IREs). The FTIR/IRS adsorption density equation is given by (formula) where r is the adsorption density, A/N is the absorbance per reflection, e is the integrated molar absorptivity, 4 is the bulk concentration of the surfactant, d. is the effective thickness, and dP is the depth of penetration. Previously, the validity of the adsorption density equation had been confirmed only from solution depletion measurements with high surface area powders. Now, FTIR/IRS studies of Langmuir-Blodgett (LB) monolayer films of fatty acid transferred to the surface of a calcium fluorite IRE .clearly validate the reliability of the FTIR/IRS adsorption density equation for quantitative analysis of surfactant adsorption. In addition, it was confirmed from the observed absorption band at 1550 cm-1 that the first monolayer of the transferred fatty acid chemisorbs at the surface of fluorite.

Jan 1, 1994

By V. Gall

The three-dimensional finite element technique combined with the progressive failure approach was utilized to simulate stress distributions in a mine section which occur in response to a longwall mining operation. Due to the availability of the Cray supercomputer, a large-scale three-dimensional finite element model was developed for the analysis. The Hoek-Brown failure criterion, which describes a realistic behavior of rock masses, was used for the simulation of progressive failure. A comparison of calculated and monitored stresses in the mine has shown that the model gives a good representation of stresses in the mine structure.

Jan 1, 1990

Keeping an eye on the future while honoring the past, Frank McAllister, chief executive officer of Stillwater Mining Co., and life member of the National Mining Hall of Fame and Museum, gave the keynote address to a packed house during the 23rd National Mining Hall of Fame and Museum Banquet in Leadville, CO on Sept. 11. McAllister?s company made news just days before the induction ceremony, when it was announced that Stillwater Mining would acquire Marathon PGM Corp. for $118 million (ME, Oct. page 14).

Jan 1, 2010

By S. D. Michaelson

Open pits and quarries are the major sources of all "hard rock" tonnage mined today. Normally, ore is fractured from the pit face by blasting and then truck-hauled to a primary crusher where processing begins; over- burden (or waste) is generally truck-hauled from the pit to dump areas. Truck haulage of blasted ore and overburden accounts for some 25 to 50 percent of total mining costs in a typical open pit and commonly is the largest single cost factor. Obviously then, cost reduction efforts should properly focus on improving existing haulage systems and developing new breakthrough techniques for material transport. Continuous flow systems for large tonnages ordinarily will result in a lower cost than batch systems such as truck or rail haulage. Continuous flow with pipelines for liquids and slurries, or conveyors for medium to coarse dry materials (in the -8 in. range) are the accepted economic answers for bulk materials handling over reasonable distances.

Jan 1, 1968

By H. Zhao, R. Liao, W. Qin

Theoretically, controlling redox potential to a relatively low value and inhibiting jarosite formation on the chalcopyrite surface would be an effective strategy to accelerate the bioleaching of chalcopyrite. In this work, using limonite as seed crystals, the effects of the goethite precipitation process on the bioleaching of chalcopyrite were studied for the first time. The bioleaching results showed that the addition of limonite controlled the redox potential in an appropriate range and promoted chalcopyrite dissolution through the removal of ferric (Fe3+) ions. X-ray diffraction and scanning electron microscope analyses indicate that limonite significantly induced the goethite precipitation process and inhibited the production of jarosite. We conclude that promoting the goethite precipitation process with limonite is an effective strategy in accelerating the bioleaching process of chalcopyrite.

By R. E. Vivas, J. A. Villa

"Located in the state of Colima, Peña Colorada is one of the largest iron ore operations in Mexico. The project is owned in equal parts by ArcelorMittal and Ternium. Though boasting a production capacity of 4.1 Mt/a (4.5 million stpy) of concentrate per year, Peña Colorada is faced with declining ore grades. In order to respond to this situation, Peña Colorada had to expand production even further. This expansion created various challenges that were overcome by the adoption and application of new technology. Examples of these technological innovations are discussed in detail in this article and include improvements in geo-modeling, mine planning, and mine operations. The successful implementation of these technologies paid for itself many times over, and has led to significant improvements in production and performance, while lowering the operating costs and reducing the variance between planning and execution.Project overviewPeña Colorada is a mining company that produces about 30 percent of the iron ore in Mexico. This project generates about 1,200 direct jobs and 3,000 indirect jobs, making a significant contribution to the local economy. Similarly, Peña Colorada invests in its local communities through numerous educational programs, scholarships, university agreements, social development, environmental agreements, etc. Peña Colorada’s operations consist of an open pit mine located in Minatitlán and a pellet plant located in the port city of Manzanillo, as shown in Fig. 1. Technological innovationsMost mining projects around the world typically follow the logic of “mining the next best ore.” Consequently, head grades tend to decline over the life of the mine. In the case of Peña Colorada, a decline in head grade combined with a decline in iron ore prices forced the operation to adapt to a new business environment and adopt new technologies to face these challenges. However, the first step along this process was to increase the confidence and reliability of the resource model. This task involved additional drillhole campaigns coupled with more detailed modeling techniques. Once the block model was completed, new optimization studies and production schedules were evaluated with new optimization tools that improved many aspects of the mine plan. The Peña Colorada block model has undergone 3 expansions to reflect additional information not available in the past. The model has expanded to the East and Southwest. The latest model expansion increased the total number of benches to 98 as a result of positive exploration results. Similarly, new geotechnical studies were prepared, which provided new guidelines for pit slope design, and new technology was implemented to monitor ground movement and slope stability. Two sectional block model views in Hexagon Mining’s MineSight 3D, along with the pit designs and geologic solids are shown in Fig. 2."

Feb 1, 2017

By R. Adsero

"A high altitude review of the state of the mining industry provided by a study of multifactor productivity shows a continuation of lower output year on year for the capital and labor inputs applied. The story is sadly similar for both U.S. mining and the Australian mining sector. In fact, according to PwC analysts, the world’s mining equipment productivity has declined 20 percent during the past seven years (Lumley, 2014). Although the reasons for the continuing decline in mining productivity are varied, the need for improvement is clear.The world’s mining industry fleet of more than 400 large draglines moves billions of tons of overburden and ore (phosphate, limestone, etc.) annually. This discussion will review a few of the tools available for improved productivity in dragline operations.Benchmarking equipment performance exposes the possibilitiesIn the September 2013 Mining Engineering cover story Graham Lumley and R. Adsero suggested that analyzing best practice equipment performance from an industrywide database for specific equipment performance improvement goals would be beneficial (Adsero, 2013). Benchmarking equipment performance by normalizing differences and then comparing specific measures of performance will provide a road map to improvement for those following the leaders. For those already performing at best practice levels, a benchmark confirms and bolsters what has already been achieved. As described in the SME February 2014 paper by this author, best practice is the average of the top 10 percent in annual output. Filling performance gaps identified by a comparison to best practice by investigating the details of the why and taking action to change, makes all the difference. This is true for all major mining equipment. Given the large gap between average performance and best practice performance most mining operations can benefit. Best practice performance provides a view of what is possible to the 90 percent majority of mining operations that are performing below the top 10 percent.For dragline mining operations, identifying specific characteristics and practices of leading dragline performance will provide a reference for comparison."

Nov 1, 2016

By Verya Nasri, Behrouz Esmaeilkhanian, Mohammad Motallebi

The Mount Royal Tunnel (MRT) is a 100-year-old railway tunnel located in Montreal, Canada. The tunnel is approximately 5 km long, 8.7 m wide and 5.5 m high, with a constant 0.6% grade. This existing tunnel will be used by the new Montreal light rail transit network, Réseau Express Métropolitain (REM). This requires the tunnel to be inspected, rehabilitated and made compliant to the recent safety standards. This paper presents the details of the structural inspection and rehabilitation of the tunnel along with the repair methods, addition of a center wall as well as the enlargement of the tunnel section.

Jun 13, 2021

By William Gleason

The mining industry is a unique space. It is one in which geologists and chemists can intersect with computer and data science professionals daily. The industry requires expertise in not just mining and metallurgical engineering, but also electrical, mechanical, environmental and more. It requires expertise in worker health and safety, behavioral science, finance and economics, as well as human resources management. The locations of mining operations are often in remote corners, and for underground activities, they are unlike anything else in the world. The industry presents those who join it a wealth of opportunities, but often struggles to overcome incorrect perceptions of safety, labor and environmental standards, making it difficult to recruit and retain employees at a time of increased demand for mined materials.

Dec 1, 2025

By R. R. Dorfler

The existing regrind circuit at the Climax Operations uses sodium cyanide and Nokes reagent to reject pyrite, copper, and lead minerals. Laboratory flotation studies were performed using feed to flotation following first-stage regrinding. The effects of conditioning time, pH, and the concentration of depressants such as Nokes reagent and sodium cyanide on the rejection of pyrite, lead, and copper minerals were investigated. The metallurgical results indicate that, in the presence of depressants, the rejection of copper is strongly dependent on the pH. Preliminary mill testing confirmed the finding. The rejection of impurities is also dependent on conditioning time. The recovery of molybdenite is independent of the variables investigated.

Jan 1, 1981

By L. C. Lang

Effective and profitable mining begins with good blasting results. While the importance of sufficient energy to break the rock is recognized, more attention should be paid to the time factor in blasting. Fragmentation, looseness and the shape of the muckpile can be improved and energy levels lowered through the use of proper delays. The long delay is also the most important parameter in establishing stable walls along the final limits of the pit. The time factor in blasting is explained through the rock acceleration process and its practical application is demonstrated by case histories.

Jan 1, 1981

By R. E. Pennington

My subject this morning is coal liquefaction technology. Actually, coal liquefaction involves a number of technologies in a very complex system. The first slide shows the major components of such a system with arrows to indicate appropriate flows. The components are the facilities for coal feed preparation and handling; the coal hydrogenation or base liquefaction section; facilities for product separation and recovery, and in addition, facilities for the production of hydrogen from coal-based sources. A very rough break- out of the investments involved in these areas is given at the bottom of the slide. Investment is spread about equally among the three areas of operations Another way of looking at it is that the investments in what might be called support facilities are of the same magnitude as the base investment in the hydrogen facilities. Therefore, it is appropriate in a discussion of coal liquefaction technology to treat it as a system composed of a number of technologies. The next slide lists the various functions in the feed preparation section along with an indication of technology status. Storage, crushing, grinding, drying of coal all have been in commercial practice for a number of years. The slurrying and pumping of coal at least in water slurries, is practiced commercially also. The heating of coal slurries in oil to high temperatures under pressure is not in commercial practice and development and testing is going on by a number of people in this area. Some rather complex phenomena occur when coal oil slurries are heated to high temperatures.

Jan 1, 1975

By T. M. Yegulalp

A short review of the current practice and recent developments is followed by a description of a newly developed approach for the solution of the optimum ultimate pit limit problem. The new approach utilizes the network modeling of the problem for solution by maximum flow algorithm. The latest developments in the implementation of maximum flow algorithm present significant time and memory savings as compared to initial development due to Ford and Fulkerson. Results of a series of computational tests are presented to demonstrate how this approach performs as compared to the well-known Lerchs Grossman algorithm. It is also shown that the solution by the new method will automatically include several optimal solutions based on predetermined number of benches to be included in the analysis.

Jan 1, 1993

By Da-Rong Chou

An optimum method for selecting exploratory drilling locations has been developed. The process has been modelled as a highly non-linear programming problem subject to constraints. Solution involves an iterative algorithm which converges rapidly and procedures have been developed to distinguish between local and global optima. The algorithm has been implemented as an interactive computer program which allows the user to influence directly the solution process and to evaluate the effect of any manual adjustments to the optimal solution.

Jan 1, 1984

By W. E. Bardelmeier

The high speed conveyor type self unloading bulk carrier concept has been around for about 70 years. Although the design was developed, refined and steadily improved in the Great Lakes, to date limited numbers of such vessels have emerged in the bulk ocean trades, and these have tended to concentrate within specific mineral trades. For example, North American gypsum companies have embraced conveyor self unloaders to the point where such vessels almost exclusively carry the gypsum requirements of this part of the world. One major aluminum company has developed an impressive fleet capability in self unloaders. Application of other ships tends to be fragmented through several mineral trades. A few years ago a new phenomonen began to appear on the Great Lakes. Whereas it had historically been accepted in that region that self unloaders were effective vessels for the minor bulk trades including limestone, coal, salt, gravel and sand; they had seldom been employed heavily in the big volume iron ore trades. Suddenly, however, the new generation of 60,000 ton Lakers which emerged were all designed as high speed self unloaders. The new vessels intended to trade especially in ore, or alternatively especially in coal, have somewhat different internal features, but the important point is that all are self unloaders.

Jan 1, 1979

By Robert L. Marovelli

Organizational development that attempts to simultaneously deal both with training and with job design parameters as they relate to mine health and safety, productivity, and quality of life is one of several areas of research that the Bureau of Mines is pursuing. The Bureau sees potential in this particular effort for reducing accidents and injuries, improving worker satisfaction and health, and increasing productivity.

Jan 1, 1981

By Cheryl M. McInnes, Graham J. Sparrow, James T. Woodcock

Three composites, assaying about 3 g/t Au and 0.75% Cu, were investigated. Each contained oxide copper minerals, iron oxides, and silicates. One composite also contained copper and iron sulphides. Maximum gold extractions by thiourea leaching were obtained after copper removal by acid pre¬leaching at pH 1.5 and redox potentials of 400 mV (Pt versus SCE). Best thiourea leaching conditions were pH 1.5, redox potentials over 200 mV, and 0.4% thiourea. This gave 90% gold extraction in 2 h with thiourea consumptions of 25 kg/t. Lower potentials gave poorer extractions. Ferrous iron additions before leaching halved thiourea consumptions. Longer leach times and the presence of sulphide minerals sometimes resulted in reprecipitation of gold.

Jan 1, 1989

By Richard B. Stein

This paper will present an overview of several hydrometallurgical processes which can be used for sea-nodule metal recovery and some simplified economics. Before going any further, here are some of the basic figures from which the economics were developed. The first is to establish a representative composition for a typical nodule feed (Slide 1). This set of chemical analysis figures can be taken as typical for a deep Pacific nodule feed and shows manganese at 30%, copper at 1.1%, cobalt at 0.2%, nickel at 13% and iron at 10% for the metals of economic interest1.

Jan 1, 1982

By G. M. Clarke

Minerals are certainly where they are found. The undemocratic distribution of the world's mineral wealth has created an incongruous inbalance: mineral-rich, scarcely populated countries supply highly-populated industrialised countries that in turn consume more minerals than they produce. This has been as much a generating force for colonisation, invasion, and war as religion, political ideals, or megalomania. The Industrial Revolution of the seventeenth century was born in Britain, a country with large domestic resources of coal, iron, lead, zinc, copper, tin, etc., as well as a large population. As consumption outstripped production imports filled the gap, particularly from its worldwide colonies. For example, when Canada was founded in 1867 more than 905 of its investments were British financed, and much of these were mineral-based. The British made similar investments in South East Asia, Australasia, the Caribbean, and elsewhere, as did the other industrialised Western European countries hungry for raw materials. Later the United States emerged as a leading industrial power, again due largely to its abundant natural resources. Consumption soon exceeded production and foreign sources were saught. American business went exploring abroad ant many a mineral resource was developed almost totally on the basis of the US market many .thousands of miles away. Closer to home, Canada was also an obvious target for the US with its rich mineral resource base, small population, and geographical juxtaposition, so much so that about the time of the 1914-18 War the US took over from Britain as the major investor in Canada, and this peaked in 1967 when the US accounted for 80% of the country's foreign investment. After the 1939-45 War Japan joined the ranks of the USA and Western Europe as industrialised powers, and they too searched the world for the deposits lacking in their homeland.

Jan 1, 1981

By Guowen Dong, Qiyong Li, Qiang Li, Tiejun Chen, Zhihong Wu, Junying Wan

In order to search for a more economical and effective roasting additive for extracting vanadium from stone coal and solve the question of the disposal of PVC waste, PVC waste was proposed as a novel roasting additive to enhance extraction of vanadium from stone coal and realize the comprehensive utilization of resources. By adding this roasting additive, the leaching rate of vanadium reached 94.5% under the conditions that the PVC waste addition was 10 wt%, the roasting temperature was 800 °C, the roasting time was 1 h, the sulfuric acid concentration was 15 vol%, the liquid-to-solid ratio was 1.5 cm3 /g, the leaching temperature was 95 °C, and leaching time was 4 h, which increased by 8.4% compared with that of blank roasting. The thermodynamics calculation showed that the decomposition reaction of mica was performed easier with the participation of HCl produced by pyrolysis of PVC. Meanwhile, The SEM-EDS and aperture test analyses demonstrated that more cracks and voids appeared in the roasted sample by roasting with PVC waste, which could facilitate the release and extraction of vanadium. Additionally, the TG-DSC analyses indicated that PVC could provide large amounts of heat for the roasting process to promote the decarbonization and roasting efficiency of stone coal because of its high calorific value.