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By H. C. Siebert

According to the "Survey of Energy Resources 1980" (1)*, which was prepared by the Federal Institute for Geosciences and Raw Materials in Hannover (FRG)for the World Energy Conference 1980 in Munich, the world coal deposits are assessed at 775 billion tce proven reserves 448 billion tce of them recoverable and 6 161 billion tce additional resources. If one ignores growth rates, the current world coal output of 2,8 billion tpy gives our recoverable reserves a static life expectancy of 175 years. With an average increase in world output of 3,2 % like between 1973 and 1980 this range would be further shortened to an alarming degree. Furthermore, the criteria used to distinguish between workable and unworkable resources give rise to the suspicion that deposit characteristics are not always taken into account to a sufficient degree. For example, little attention is paid to major ?Bonitaet" - factors such as dip and seam thickness. There have been wide-ranging scientific discussions on the lower limit for workable coal resources, but no such limits have been set at the other end of the scale. Otherwise it is well known that performance and costs are badly affected den in level and moderately inclined seams the seam thickness is more than 4 to 5 m, because special mining methods have to be used beyond this limit. These are associated with significantly higher costs than with the winning of seams of ?normal? thickness.

Jan 1, 1985

By E. A. Sigworth

Our interest in metallurgical applications for activated carbon was thoroughly aroused when laboratory studies indicated that each dollars worth of carbon could retain as much as four dollars worth of tin. Since then other data was developed suggesting many Potential uses in the metallurgical field it is hoped that, the information presented in this paper may encourage studies by knowledgeable individuals in metallurgical operations. Activated Carbon accomplishes its results by adsorption which involves selective removal of materials from solution by holding the compounds on the carbon surface at the active areas. An example of adsorption is the dyeing of cloth where the dye is selectively held on the cloth surface and the concentration in the dye solution is thereby reduced. Many theories exist on, adsorption, but the predominant factors involved in metallic ion adsorption probably are that adsorption is indirectly proportional to solubility and is benefited by high concentrations acting to squeeze out molecules in smaller amounts.

Jan 1, 1962

By Lihong Zhou, DAVOOD BAHRAMI

A reliable and stable ventilation system is essential to the safe operation of underground mines. The stability of a mine ventilation system becomes extremely critical while responding to a fire incident since an unstable ventilation system will pose a risk of airflow reversal. The reversed airflow could bring the fire contaminants such as toxic gases and smoke unexpectedly to working areas. In the past few years, there has been a growing interest in the study of ventilation network stability using the concept of resistance sensitivity, which is described as an indicator of how the airflow in an airway is reacting to a resistance change of other airways. Several methods of calculating the resistance sensitivity in a mine ventilation network have been carried out by researchers and scholars around the world. However, the proposed methods heavily rely on a vast amount of mine ventilation simulations, which are very time consuming and computer-power intensive, especially for a large-scale mine ventilation network. In this paper, a derivative method calculating the resistance sensitivities with a single mine ventilation simulation has been developed and implemented into a mine fire simulation software, MFIRE. The results from the derivative method were verified against the results from a traditional method. The derivative method has been proven to be reliable and accurate.

Jun 7, 2022

By S. Borner Schweizer

An overview over SAM’s approach to assess corporate sustainability performance illustrates how sustainability challenges are linked to trends, assessment criteria and finally company performance. This process is exemplified with some general and industry specific criteria. Lastly, results of the Dow Jones Sustainability Assessment 2004 show a considerable gap between leading and average companies. Best practice examples demonstrate how lagging companies could improve their sustainability performance.

Jan 1, 2005

By Donald M. Ulbrich

As all of us know, the "heat" is on for western coal. The need for western coal is critical if the nation is to reach the goals of Project Independence by 1985. Without the development of western coal, the goals will not be met. It's that simple! That's because 50 percent of our nation's coal reserves lie in the states of North Dakota, Montana, Wyoming, Colorado, New Mexico, Arizona and Utah. And surface mining is the key to unlocking these reserves. Of the nine states in the coal provinces, five-Wyoming, Montana, New Mexico, North Dakota and Arizona-are the best examples since surface mining accounts for 88 to 100 percent of the coal mined in each of these states. Collectively, their annual production more than doubled between 1969 and 1972, rising to 35 million tons per year. And, taken individually, each state's production has more than doubled, also. Total annual production from these five key states could very well exceed 180 million tons per year by 1980-four times the 1972 production level. The biggest producer among the five is Wyoming. Wyoming's production tripled since 1969 to nearly 14 million tons in 1973. So the heat is on for western coal, especially from Wyoming. Now we come to the question of how to mine this increasingly precious mineral. What are the available methods? First, let's take a brief look at several characteristics of western coal deposits.

Jan 1, 1975

By Emily Dieckman, Claire Kincaid

"When most people think “miner,” they picture an older white man in a dusty shirt and suspenders. He’s holding a gas lamp and a pickaxe, peering at the walls of a dimly lit cavern. This image, while steeped in heritage, is no longer representative of what mining is: a global, increasingly diverse industry.It’s an industry made up of individuals like Zambian-born Chushi Mwewa, PE, president of Southlands Engineering, LLC in the United States and managing director of Southlands Engineering Limited in Zambia; Navajo tribe member Peter Denetclaw, manager of environmental programs and Navajo relations at Freeport-McMoRan; and Chinese and Jewish Alyssa Hom, a project engineer at McCarthy Building Companies.According to the Austrian Federal Ministry of Science, Research and Economics, 168 out of the world’s 195 recognized countries have some mining or mineral resources activity, and the mining industry directly employs more than 25 million people across the globe.However, according to McKinsey & Company’s 2017 “Women in the Workplace” study, white males hold 67 percent of C-Suite positions and 70 percent of senior vice president positions in the corporate world, and mining is no different. This uniformity among leadership has been tied to lower levels of employee engagement, innovation and business growth. The bottom line is this: Diversity is good for business. The question industry leaders must now ask themselves is not “Will we promote diversity?” but “How will we promote diversity efficiently and permanently?”More than 80 industry professionals, consultants and students gathered to discuss this question and share stories at the “Developing Diversity in Mining” workshop organized by the University of Arizona’s Lowell Institute for Mineral Resources (IMR), held during the 2017 SME Arizona Conference in December 2017.Brad Ross, co-director of the IMR and one of the facilitators of the workshop, said he felt diversity was important to discuss because he has witnessed its benefits throughout his career in the mining industry.“By creating a team of people with different experiences and perspectives, a company is better equipped to see the big picture and to creatively tackle problems,” he said. Speakers from industry and academia,including Mwewa, Denetclaw and Hom discussed the challenges surrounding achieving diversity and inclusion as well as the roles and responsibilities of different stakeholders."

Jan 2, 2018

By Qingming Feng, Jinhong Zhang

This study investigates the application of fly ash as a high-strength, water-resistant precast construction material through geopolymerization. The experimental results show that working conditions such as water content, sodium hydroxide (NaOH) concentration, curing temperature and curing time significantly affect the mechanical properties of the geopolymer matrix. Through optimization, compressive strength above 100 MPa was achieved, and the optimum working conditions were found to be NaOH concentration of 10 M, water content of approximately 14 to 15 percent, and curing at 90 °C in an oven for one day or at ambient condition for three weeks. Water-soaking tests show that the geopolymerization product has high water resistance without losing noticeable compressive strength even after one month of soaking time. The findings provide a novel method to apply fly ash as a high-strength, water-resistant precast construction material.

By H. Habenicht

Requirements for full extraction in underground coal mining call for inexpensive, safe, techniques to be competitive with conventional methods. Longwall and shortwall systems are to some extent employed for this purpose. Another method would be rib pillar extraction (and pillar extraction). These methods are compared with each other with respect to procedure, equipment, safety, roof control, investment, output, performance, costs The advantages of r.p.e. show this method very attractive. Number and cost of equipment are lowest. Safety and roof control becomes improved by a mobile roof support recently developed in Austria. Its successful use in the R.S.A. is being explained.

Jan 1, 1986

By Matthew Deutsch

A common casualty of modern openpit mine optimization is the assurance that the resulting design is actually achievable. Optimized mine plans that consider value and a bare minimum of precedence constraints do not, in general, translate into practical, operational mine designs that can be used in the field. Ultimate pits may come to a sharp point at the bottom. Schedules may require taking small parcels of material from many disparate areas of the pit in a single period, and grade control polygons may be ragged, narrow and not minable with realistic equipment. In this paper, these three fundamental openpit mine optimization problems are addressed by encoding them as maximum satisfiability problems. Maximum satisfiability provides a useful framework for problems that are nonlinear and may guarantee the optimality that metaheuristics cannot.

By Constance F. Acton

This paper presents an overview of -- the carbon-in-pulp process for gold and silver recovery as seen in the early 1980's. Traced back to its origins in the mid-nineteenth century the process development through the present state-of-the art is described. The process technology and equipment design are described in detail for the carbon-in-pulp process. A typical process flowsheet is given with a description of appropriate design criteria. Technical advantages and disadvantages as compared to the traditional countercurrent decantation process are discussed including some illustrative comparisons of capital and operating costs. A summary of currently operating carbon-in- pulp plants throughout the world is given with an insight into future developments in this industry.

Jan 1, 1982

By RICKARD HANSEN

Vehicle fires in underground mines pose a certain risk for which measures to prevent or mitigate the fires are highly important. Fire protection measures can be divided into active and passive measures, where active measures require an external power to work in the event of a fire, and passive measures could include an existing partition preventing fire spread. As passive fire protection does not rely on activation, it is expected to provide high reliability and a robust solution, and should be considered during the design process. This paper investigates passive fire protection measures that could be implemented in the design of mining vehicles. It was found that passive fire protection should include the use of several measures simultaneously to ensure fire protection throughout the different phases of a fire. Threshold distances for fuel components were calculated, and it was found that combining hydraulic hoses and electrical cables resulted in larger threshold distances. A pool fire along the underside of a vehicle will pose a certain risk, and passive measures should be focused on ignition prevention, making high demands on the insulation/shielding along the underside. Any occurring tire fire may pose a challenge, and the priority should be on preventing ignition. Potential measures include shielding the wheelhouse and applying fire-resistant sealings.

By C. Nesbit, N. Duru

During the cyanide leaching process of gold and silver, ores that come from the transition zones which typically con-tains low levels of sulfide may produce one or more of the following reduced sulfur species: sulfide (HS ), polysulfides (Sn ), thiocyanate (SCN ), thiosulfate (S2O3 ), trithionate (S3O6 ), tetrathionate (S4O6 ), pentathionate (S5O6 ) and hexathionate (S6O6 ). The actual speciation of the reduced sulfur species in the circuits will primarily depend on the re-dox potential, pH, cyanide levels and existing sulfur species in recycled process water, as well as the presence of other reac-tive metal species. Development of an accurate analytical method for sul-fur species in cyanide leaching units of gold ores where sul-fur speciation occurs has an important role in explaining the metal recovery deviations. This study presents the speciation of sulfur species and development of an ion chromatography method to analyze the reduced sulfur species thiocyanate, thio-sulfate, trithionate and tetrathionate in cyanide leaching circuits for gold ores. The method developed has resulted in the precise quantification of target sulfur species in leach solutions.

Jun 1, 2024

By L. P. Meade

Dimension stone and salt are two of the oldest industrial minerals utilized. Salt has been and still is a necessity to the well being of man. Dimension stone on the other hand has been utilized by man to glorify conquests - both in the battlefield and corporate arena. Both commodities are important, but dimension stone has an additional use in that the survival lessons learned by the domestic industry can be applied to other contemporary industrial minerals, Specialization in the market place and customer service have allowed domestic producers to survive: subsidized foreign competition, obsolete equipment, and lack of capital.

Jan 1, 1986

By H. Kimura

A new technology for ironmaking based on direct gaseous reduction of iron ore concentrate is under development. The process is based on the flash reduction of the concentrate particles in a gaseous reducing agent, such as hydrogen, natural gas, a reducing gas generated by partial combustion of coal, or a combination thereof. This technology is expected to drastically lower CO2 emission and reduce energy consumption by about 38% of the blast furnace requirements. The energy savings are possible largely due to the elimination of pelletization and cokemaking. Process design and simulation using hydrogen as the reductant for iron ore concentrate have been performed. A process flow sheet composed of a flash reactor, heat recovery system, water removal system for purifying recycled hydrogen, and all connecting streams was evaluated using the METSIM software. Ironmaking using two reactors was also designed and simulated, which could reduce the total required amount of hydrogen although it would increase the complexity of the flow sheet and operation.

Jan 1, 2010

By Emily Sarver

"Across all sectors and commodities, a common theme is driving progress in raw resource supply: sustainable development (SD). Over the past few decades, the mining and minerals industries for their part have undertaken significant and intentional changes at every level to become more responsible — no longer to just their shareholders, but also to the environment, to the communities in which they operate and to society at-large. Led by some of the global majors, these industries have indeed helped to define and operationalize the basic principles of sustainable development. Now in the midst of a full-on cultural shift, they are also key players in the continual effort to re-examine and calibrate practices to meet dynamic and increasingly complex objectives.SME’s technical position statementAs a home for so many technical experts and practitioners, SME has long recognized the importance of a commitment to sustainable development by the mining and minerals industries. In April 2016, the Society formally adopted a technical position on the topic following years of participation in, and support for, related activities. The full position statement appears below. It was drafted, revised and presented for approval to the board of directors by SME’s Sustainable Development Committee.Statement of Technical Position on The Mining Industry and Sustainable Development:• The National Environmental Policy Act of 1969 (NEPA) and the Surface Mining Control and Reclamation Act of 1977 (SMCRA) imposed considerable environmental restrictions on the mining industry; SME has always reinforced strict adherence to the laws.• In 2002, SME established a Sustainable Development Committee to lead its efforts in this area and to propel the organization into global prominence.• SME is a signatory to the Milos Statement of 2003 on Sustainable Development, so it is committed to providing scientific, technical, educational, and research skills in minerals, metals and fuels.• SME recognizes that SD programs adopted by the industry have a tangible return on investment through brand recognition and loyalty, facilitation of permitting, reduced occurrence of community protests and vandalism and diminished political risks.• SME actively promotes educational programs that encourage professional growth and interaction with the engineering professional community through books, articles, symposia, short courses and/or conferences on sustainable development in the mining and minerals industries.• SME has developed abundant expertise to provide balanced advice to government bodies, congressional staff and other interested organizations."

Jan 12, 2017

By Jessica M. Wempen

"Differential Interferometric Synthetic Aperture Radar (DInSAR), a satellite-based remote sensing technique, has application for monitoring subsidence with high resolution over short periods. DInSAR uses radar images to measure centimeter-level surface displacements. In the images, ground resolution can be relatively high, with each data point (pixel) representing the average displacement over an area of several square meters. The image data are acquired regularly which allows subsidence to be monitored sequentially over short periods; imaging periods typically range from weeks to months.Monitoring subsidence over short periods with high spatial resolution has potential to provide insight into the dynamics of subsidence and into relationships between mine advance and subsidence. In this study, for three longwall mines in the western United States, initial subsidence occurring at the start of longwall advance is quantified over short periods (12 to 72 days). C-band interferometric wide swath Synthetic Aperture Radar (SAR) images from the Sentinel satellites are used to quantify the subsidence. Overall, the data show initial development of subsidence, expansion of the subsidence trough, and the advance of subsidence in the direction of mining.INTRODUCTIONApplied Differential Interferometric Synthetic Aperture Radar (DInSAR)Differential Interferometric Synthetic Aperture Radar (DInSAR) is a satellite-based remote sensing technique that can be used to quantify small displacements of the Earth’s surface. Using data from the Seasat satellite, which was launched in 1978 (Jet Propulsion Laboratory, 2018), studies by Goldstein, Zebker, and Werner (1988) and by Gabriel, Goldstein, and Zebker (1989) applied Synthetic Aperture Radar (SAR) interferometry to topographic mapping and displacement monitoring. These studies established the potential for broader applications of radar interferometry. Studies by Foxall, Sweeney, and Walter (1998), Wright and Stow (1999), and Carnec and Delacourt (2000) represent some of the earliest evaluations of DInSAR for mine subsidence monitoring. All three of the studies demonstrated the application of DInSAR for quantifying mine subsidence. They also demonstrated difficulty accurately measuring subsidence over long periods due to data decorrelation. DInSAR continues to be evaluated as a tool to quantify surface deformation related to active and historic mining. For example, see Vervoort and Declercq (2018), Wempen and McCarter (2017a), Chen et al. (2013), and Liu et al. (2013). Technologies associated with SAR interferometry continue to develop. Recently launched satellites have relatively high spatial and temporal resolutions, and data processing methods and data accessibility are improving."

Jan 1, 2019

By Tácio Ferreira, Liz Diaz

Capstone Copper’s Pinto Valley Mine faced challenges in recovering rock and ore on final walls because of geotechnical constraints that require restrictions on methods for loading blastholes adjacent to the pit boundaries to preserve wall stability. The operation had been using the same drill-and-blast designs for years. With changing geology, such as harder rock, as mining progressed, material was being left unmined in final walls because of poor breakage. The amount of unrecovered, unprocessed ore was estimated at 345 kt/a (380,000 stpy) generated from an average of 60 final wall blasts performed annually. The engineering team from Capstone and Dyno Nobel engaged to minimize the amount of material left on the final pit walls. This article presents how data were collected and design standards reviewed, and the opportunities that were found to improve ore recovery from pit final walls without increasing drilling and blasting costs. The results collected from implementing the new design on two benches showed the potential for extra revenue of approximately $3.6 million generated annually from reducing final wall unrecoverable underbreak by nearly 71 percent on the mine’s highwalls.

Aug 1, 2025

By Eduardo Velasco, Paz Navarro, Alfonso Navarro, Claudio Cimiotti, Alejandro Sanz, Nick Karlin

The LA Effluent Outfall tunnel is a 7-mile long, 18' internal diameter, secondary treated effluent discharge tunnel currently under construction by Dragados USA for the Los Angeles County Sanitation District No. 2 (LACSD). The purpose of this tunnel is to add redundancy and increased capacity for discharge of secondary treated effluent from the LACSD’s Joint Water Pollution Control Plant, located in Wilmington, California within Southern Los Angeles County. Current discharge from this facility flows through two existing tunnels of 8' and 12' horseshoe profile, constructed in 1937 and 1958, respectively. When the new tunnel is complete, it will add an additional capacity of 670MGD in peak wet weather flow conditions. Geology of the roughly 7 mile long tunnel was divided into six reaches by the contract documents. Tunnel Reaches (TR) 1 to 3, comprising 19,550' will be excavated in alluvial sands of the San Pedro and Lakewood formations, with cover ranging from 45 to 90 feet. In this reach the tunnel intersects the seismically active Palos Verdes fault Zone. TR 4 is a 1,600' transitional zone between alluvium and the rock formations of the Palos Verdes (PV) Hills, comprised mostly of Malaga Mudstone. TR’s 5 and 6 total 15,591', and are within the rock formations of the PV Hills with overburden ranging from 315' to 475'. The primary constituent of the PV Hills is Altamira

Jun 13, 2021

By Robert C. Maxton

The foundry industry is a basic source of structural component for all industry. Millions of tons of castings are produced annually in both ferrous and nonferrous alloys. These castings are subjected to a wide variety of heat treatments, finishing techniques, mechanical tests and machining operations. Through all of these steps the quality of the casting is of paramount importance to the end use of the product. The Quality Assurance Program at Minneapolis Electric Steel Castings Company is designed and established to provide a superior product for both original equipment manufacturers and the mining industry.

Jan 1, 1982

By J. D. Mc Beth

The Carlin Gold Mining Company, a wholly owned subsidiary of Newmont Mining Corporation has been successfully operating an open pit gold mine and cyanide mill for approximately the past ten years. It is a unique operation in that about 20 percent of the mill feed is a carbonaceous ore refractory to cyanidation that must undergo a pretreatment stage developed for, and by, Carlin. The mine and plant are located in the Tuscarora mountain range is north-eastern Nevada near the towns of Carlin and Elko. Claims were staked at the minesite in 1961 and 1962. A drilling program was initiated late in 1962 and after drilling a total of 250,000 feet of rotary drill holes an estimated 9,300,000 tons of ore at a grade of 0.32 ounces of gold per ton was delineated.

Jan 1, 1975