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By A. A. Bilgin

The prevention of acid mine drainage (AMD) in situ is more attractive than down-gradient treatment alternatives that do not involve source control. AMD source control can be achieved by shifting the microbial activity in the sulfidic rock from pyrite oxidation to anaerobic heterotrophic activity. This is achieved by adding biodegradable organic carbon amendments to the sulfidic rock. This technique was applied to an abandoned coal mine pool in Pennsylvania. The pool had a pH of 3.0 to 3.5. Following treatment, near-neutral pH and decreased effluent heavy metal concentrations were achieved. In situ bioremediation by the enhancement of bacterial iron and sulfate reduction is a promising technology for AMD prevention.

Jan 1, 2007

By William Gleason

Since 2004, Dave Kanagy has served as the executive director and chief executive officer of SME. In that role, he has worked with 22 SME Presidents, traveling the world to represent the Society. His prestigious one-million-mile status with United Airlines is a testament to these efforts. He has been to six of seven continents while leading the Society on a journey from a struggling association in 2004 to the largest and arguably the most influential professional mining society in the world. In the following pages, some of those past SME Presidents reflect on their time with Kanagy and paint the picture of a visionary leader who was willing to make the hard decisions for the betterment of the Society while remaining open to new ideas and opportunities. One of his first accomplishments as the executive director was to streamline the SME Boad of Directors from 29 members to nine, making it much more effective. With a keen financial sense, he was able to add value while cutting excess to expand the Society in every measure. As the leader of SME, Kanagy helped facilitate much of the Society’s growth and innovation as the world’s largest mining related organization. He has a B.S. degree in industrial education from the University of Maryland, an M.S. degree in technology education from Eastern Illinois University and is a certified association executive by the American Society of Association Executives. Under his leadership, several unique programs were created or advanced, including OneMine.org, the world’s foremost online mining research library. He enhanced legacy programs and increased collaboration with international organizations. Kanagy is the recipient of prestigious awards, including the Colorado Society of Association Executives’ Professional of the Year award and the Mining and Metallurgical Society of America’s Gold Medal award.

Feb 1, 2026

By Lance Kolbush, Alex Vaughn, James Fisher, Michael Barish, Tony Toney

Somerset International has worked to enhance the recovery of sub-20 micron particles in our patented Sub325 Systems by introducing chemicals in the systems prior to the centrifuge. This paper details four cases of such enhancement. Two on the fine coal recovery side at a 325 tph plant in Central PA and Warrior Met Coal 7 plant. Two on the tailings dewatering side at a 1200 tph Southern WV plant and at Warrior Met Coal 7 plant.

Feb 22, 2026

By Mohammed Sakr

The empirical relationship between torque measured during installation and pile capacity has gained a wide acceptance in the helical pile industry in the last few decades. This paper presents a theoretical model developed to estimate torsional resistance of cohesive soils to helical pile installation. The proposed torsional resistance model was then used to establish torque factor, Kt, a factor that is widely used in the industry. The results of the study indicated that the Kt factor is a function of the load path (i.e. tension or compression), pile geometry and soil properties. The assessed Kt factors in tension and compression were validated by the results of 74 installation records and full-scale helical pile load tests. A parametric study was also performed to qualitatively assess the relative importance of different parameters that affect the Kt factors.

Aug 1, 2013

By Z. Duan

A novel concept involving the deployment of chemical stabilization has the potential to eliminate the need of slurry impoundments and significantly reduce the release of trace elements from the high surface area fine coal waste. The process involves mixing the fine waste generated from the underflow of a thickener operation with chemical stabilization agents to tie up the water and to create a solid waste material that can be discharged directly. Portland cement, sodium silicate, F type flyash, C type flyash and hydraulic lime were evaluated as stabilizing agents. A detailed experimental study has been conducted to identify the conditions that provide the maximum compressive strength within a short curing time. Results to date show the ability to achieve compressive strengths adequate for equipment to maneuver on using a Portland cement concentration of around 10% by weight. Quick-setting concrete was not found to enhance stabilization time and compressive strength.

Jan 1, 2012

By P. G. Vikre

Several factors have caused less emphasis to be placed on geologic mapping in mineral exploration in the last 15 years. These include opportunities for "easy" discoveries of near surface gold and silver deposits in developed countries, and of base metal deposits as well in less developed countries, a decline of emphasis on geologic mapping in many universities, and a decline of useful mapping by government agencies in many areas. Geologic mapping is simply a way of recording geologic observations on volumes of rock larger than can be seen from one place. Since most geologic processes involve systems larger than this, mapping is also essential to understand the significance of observations made on smaller volumes of rock, such as thin sections and sample taken for chemical or isotopic analysis. To be useful, the observations recorded through geologic mapping are then interpreted to arrive at an understanding of the 3D geometry and geologic history of a volume of rock, which is used to direct mineral exploration, or any number of other purposes.

Jan 1, 1995

By R. L. Virta

Common clay is a natural, fine-grained material composed of hydrous aluminum silicates. Shale is a laminated sedimentary rock that is formed by the consolidation of clay, mud or silt. Production About 150 companies produced common clay and shale in 41 states. In states not reporting production, common clay and shale probably was mined and sold for construction applications by companies not participating in the U.S. Geological Survey (USGS) canvass of producers. Domestic production in 2005 was estimated to be 24.8 Mt (27.3 million st) valued at $176 million. This was based on a preliminary survey of the common clay and shale industry. The leading producer states, in decreasing order by tonnage, were North Carolina, Texas, Alabama, Georgia and Ohio.

Jan 1, 2006

By Matthew Preedy, Anthony Pooley, Mike Wongkaew, Dirk Bakker, Raghu Bhargava

Sound Transit’s ST3 program will add 62 miles of light rail to the Puget Sound area, including connections to the neighborhoods of West Seattle and Ballard. These connections include considerations for both elevated and tunnel alternatives in West Seattle and Ballard, as well as a new tunnel and six underground stations in the densely developed downtown Seattle. This paper describes the conditions and constraints along the corridor, and the latest development in the ongoing process to plan the underground guideways and stations.

Jun 13, 2023

By Brian H. Kaye

Efficient design of grinding circuits for efficient production of ultrafine material requires rapid feedback of information concerning the fineness of material leaving the grinding device. Generating this information requires efficient sampling and adequate rapid characterization of the material leaving the grinding machinery. Recent developments-in electrooptic inspection of dry end wet material leaving a grinding device are critically reviewed. New methods for characterizing ultrafines are discussed. A rapid operating automated cybernetic (intelligent) permeability device for automatic control of grinding circuits using Blaine index and other fineness indices is described.

Jan 1, 1983

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 Wu Aixiang, Zhou Qian, Zhou Zaibo, Liu Juanhong, Wang Hongjiang

To improve the pumping capacity and engineering efficiency of fresh thickened tailings slurry, a high charge density superplasticizer was developed to improve the rheological properties of tailings slurry. The effects of superplasticizer content, the concentration and fineness of tailings, the proportion and type of cementitious materials, temperature, and hydration time on the rheological properties of unclassified tailings slurry and backfill materials were studied. The variation characteristics of the slurry yield stress, plastic viscosity, and thixotropy with different factors were measured by a Brookfield R/S-SST plus rheometer. The experimental results of fresh thickened tailings illustrated that the higher the concentration of the slurry and the finer the tailings, the worse the rheological properties of the slurry. The results of cemented paste backfill materials indicated that the rheological parameters increased as binder content and time increased. The rheological parameters decreased as the temperature increased. The addition of a superplasticizer reduced the rheological parameters and improved the rheological behavior of the fresh thickened tailings and cemented paste backfill materials, which was beneficial to the slurry’s pipeline transportation. This paper can provide technical guidance for slurry transportation in the backfill system and provide a reference for designing the superplasticizer used in tailings.

Jan 5, 2022

By T. J. Nelson

Natural aggregates, primarily stone, sand and gravel, are recovered from widespread, naturally occurring mineral deposits and processed for use primarily in the construction industry. They are mined, crushed, sorted by size, and sold loose or in concrete products to build roads, houses, buildings and other structures. Smaller quantities are used in agriculture, cement manufacture, and chemical and metallurgical processes. The growth of cities, their buildings and the highways that connect them have created demand for enormous quantities of aggregates. Consumption has now reached 9 t (10 st) per person and continues to grow faster than population. The aggregates industry is the largest mining industry in the United States in terms of production by weight, by volume and by number of active operations. About 80 percent of the concrete pavement and more than 90 percent of the asphalt pavement is composed of aggregates.

Jan 1, 2006

By S. K. Sharma, ANKUSH GALAV, G. S. P. Singh

Providing a suitable protective water barrier pillar (PWBP) is common to reduce inundation hazards in underground coal mines. The imperative factors influencing its performance include the water head acting on the pillar, cover depth, pillar width, strength properties, and permeability characteristics. The mechanical failure of such pillar is a stress-controlled phenomenon, whereas the hydraulic failure is a strain-based phenomenon. A finite-difference numerical modeling approach was developed to study the hydro-mechanical coupled behavior of protective water barrier pillars. The mechanical stability was evaluated in terms of the percentage of failed (ZoF) and intact zones. The influence of the strain-controlled weakening on the permeability of the flow medium was studied through the coupling of the mechanical and hydraulic effects. The coupled steady-state model was used to estimate the outflow rate and its hydraulic stability. The adequacy of the protective pillar was also investigated by assessing mechanical stability and capability to resist hydraulic pressure against the maximum expected water head. A seepage rate-based classification system has also been proposed to evaluate the seepage potential and assess the hydraulic stability. The model has been validated for two case studies at the cover depth of 136–189.5 m and the existing pillar width of 16–42 m against the water head of 25–141 m.

Aug 18, 2022

By William R. Yernberg

Most citizens take it for granted, but minerals produced in the mines of the western United States, including Colorado, are crucial to nation’s standard of living and quality of life, said Colorado’s Gov. Bill Owens in his welcoming remarks at the 106th National Western Mining Conference. The conference, which was organized by the Colorado Mining Association (CMA), was held Feb. 4-6, 2004, in Denver. Attendance was425, up substantially from last year’s meeting. The meeting included the CMA annual membership meeting as well as the CMA chairman’s and president’s reports. The meeting also included awards presentations in which companies were recognized for their efforts in pollution prevention, health and safety, and reclamation. The conference also included a tradeshow.

Jan 1, 2004

By Byron T. Darnton

Gravity concentration at the Pegasus Gold/Montana Tunnels Mine, near Helena, MT, began in June 1991 when a coarse-gold-scalping circuit was commissioned. It processes a small portion of the ball-mill circulating load to reduce the risk of gold particles that are too coarse to float from advancing to flotation. The circuit also cost-effectively enhances overall gold recovery and payable gold ounces. This gravity circuit has been a major success. Since the circuit was commissioned, throughput has increased 30%. Several modifications and improvements were made during the last three years that allowed the gravity circuit to keep pace with the higher tonnage. The overall approach to gravity concentration at Montana Tunnels has always been to optimize production rather than maximize the gold ounces produced. This philosophy has now yielded a circuit expansion and relocation project. It will allow for an estimated 50% increase in gravity gold production, while significantly reducing the unit costs of production.

Jan 1, 1995

By Tassos Grammatikopoulos, Mike Johnson, Niels Verbaan

Seabed polymetallic nodules, which contain significant quantities of metals key to electrification such as nickel (Ni), cobalt (Co), copper (Cu) and manganese (Mn) can be processed using several different metallurgical processing options, including direct smelting and subsequent hydrometallurgical refining of the copper/nickel matte; ammoniacal leaching (gas reduction or Cuprion); and acid leaching (often reductive). Many of these approaches suffer from reduced cobalt extraction, difficult physical performance, or overall circuit complexity in general, leading to increased risk to the overall project. SGS has considered the pressure acid leaching of nodules for further investigation, as publicly shared data on this processing route stem from the 1970s and 1980s, and are not always easily accessible. This article details the series of tests conducted and provides updated results obtained — high Ni/Co/Cu recovery with limited manganese/iron (Mn/Fe) — as well as comments on the potential treatment options on the product solution and residue.

Sep 1, 2025

By Mike Ghassemi

It is clear that precise overground and under-ground mapping is an important factor for all designers. Due to rapid changes in underground construction, tunnel designers are increasingly in need of updating project information. This article explains the latest techniques for detecting under-ground utilities as well as underground mapping. Global Positioning System (GPS) is a very ac-curate and popular navigation and mapping system that has been used extensively above ground, but is not used for underground mapping as signals are not strong enough to pass through ground or water. Most underground techniques were developed for military applications during the first and second world wars. Later, the techniques became public. For example, ground penetrating radar was developed for the military in 1970 to be used for locating tunnels under the demilitarized zone between North and South Korea. Later, the same technique was used for detecting unexploded ordinance such as plastic land mines.

Jan 1, 2011

By J. E. Kulas

Red Dog is a Mississippian to Permian aged sulfide deposit located in the western Brooks Range north of Kotzebue, Alaska. It belongs in the family of black Shale hosted sedimentary exhalite deposits but lacks classic sulfide sedimentary textures. Pervasive silicification, and a significant portion of the mineralization, is replacement in nature. An extensive feeder vein system cuts the footwall and the exhalite package. A Jurassic to cretaceous age compressional event has repeated the ore section through thrust faulting and folding. The orebody contains 77,000,000 metric tons averaging 17.1% Zn, 5.0% Pb and 82 g per metric ton of Ag. Weathering has locally altered the sulfides to sulfates and formed elemental sulfur.

Jan 1, 1992

By L. B. Hales

Expert control of grinding and flotation plants has been successfully used in the minerals industry since the 1970?s. The earliest of these systems were written in a hard-coded fashion in FORTRAN, BASIC or Pascal. Second generation systems were built using the first experimental expert system shells that were being developed in the artificial intelligence community. Later systems were deployed in expert systems designed for real-time processing plants that also include the ability to model the process with neural network models and optimize setpoint selection through the use of genetic algorithms. [1,2] In spite of the fact that significant performance increases have been achieved using these systems they are not perfect and can be improved. They suffer from the static nature of their rules and to a degree the process models. There is an opportunity to further increase system performance by systematically taking advantage of the tremendous amount of data produced by the expert system to improve the design, the heuristic rules, the model topologies and the use of the models. Data mining refers to extracting or mining knowledge from large amounts of data where the objective is to automatically analyze, classify and summarize the data to automatically discover and characterize trends in it and to automatically flag anomalies. [3] Clearly, modern process control systems are capable of collecting vast amounts of data. Without a doubt, these data contain important information on the operation of our plants and their ultimate optimization. Coupling the information mined from these data with Expert Control Systems should produce more effective control and greater knowledge of the grinding process and the flotation process. Now, with the advent of effective monitoring of entire minerals plant electric consumption it is possible to not only optimize plant production in real-time it is possible to analyze total plant electrical consumption and incorporate it into the plant control logic thereby improving the overall plant economic performance. This is particularly important with the ever more complex power contracts that plants operate under.

Jan 1, 2012

By Wedam Nyaaba, Samuel Frimpong, Bruno Ayaga Kansake, Irene Akalanyaba Ateng

Haul truck capacities have increased due to their economies of scale in large-scale surface mines. These high-capacity trucks impose dynamic loads on haul roads. A previous study estimated the dynamic forces imposed by ultra-large trucks on haul roads to be more than three times the static load. These dynamic forces exacerbate haul road stresses and deformation. Current haul road response models are 2D and use static truckloads for low-capacity trucks. No models capture the ultra-large truck dynamic effects on haul road structural response. This study uses 3D finite element (FE) modeling to compute the haul road response to ultra-large truck dynamic loading. The dynamic forces were modeled using multibody dynamics (MBD) in MSC.ADAMS. These forces were used in an FE model developed, verified, and validated in ABAQUS, to simulate the response of the haul road to the dynamic truck forces. The road was modeled using an elastoplastic Mohr-Coulomb model. The results showed that road deformation decreases with increasing layer modulus and increases with increasing payload. Increasing the base modulus from 100 MPa to 450 MPa reduced the maximum deformation from 258 mm to 62 mm. When the subbase elastic modulus increased from 100 MPa to 500 MPa, the maximum deformation decreased from 160 mm to 84 mm. Increasing the payload from 0 to 120% of the rated load increased the maximum wearing surface deformation from 131 mm to 216 mm. This study forms a basis for designing structurally competent haul roads for improving haulage efficiency and truck and operator health.

Jan 7, 2023