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By Tim McMahon

"A slurry is any combination of liquids and solids where solids make up more than 10 percent of the mixture. Mining operations create various types of slurries from processes such as dewatering, bitumen extraction in oil sands, concentrator plants, milling operations, tailings, lime addition and so on. The mines then transport these slurries through pipelines (Fig. 1).Slurry valves are used when the mine needs to transport ore a long distance and there are no other viable transportation methods, such as roads or railroads.Severe service valves must be used in slurry applications and they must be tested to ensure reliability. This article describes how Emerson designs and tests its Fisher valves for use in mining slurry applications.Slurry pipeline valvesWithin a slurry pipeline system, valves are required as part of the pumping stations, choking stations and isolation stations. There may be multiple pumping stations depending on the length of the pipeline or the terrain it crosses. Choking stations are used to reduce the velocity and the pressure in the pipeline, either before a pumping station or at the end of the pipeline, and to ensure the pipeline does not slack (remains full and pressurized). Isolation stations exist so that a pig (a device sent through a pipeline to clean or inspect the pipe) can be inserted or removed from the pipeline.Typical valves used in a slurry pipeline are severe service ball valves. The valves use floating balls that are held between the seats and are not pinned or permanently attached to the shaft that rotates the ball. The inside diameter of the ball typically matches the pipeline inside diameter, enabling the pipeline to be cleaned or inspected with a pig.They can be built to accommodate the high pressures required for the typical slurry pipeline. These pressures can require up to ASME Class 2500 valves and flanges. The valves can get qlarge, up to NPS 36 inches.Specialized segmented ball valves and slurry knife gate valves are also used in some slurry applications when pressures are lower, in the ASME Class 150-300 range."

Sep 1, 2019

By J. N. Cox

Coal preparation is based on the properties of noncombustable materials (impurities) in coal being different from the organic constituents. The most commonly used property difference is density, via its affect on settling rates; and either gravitational or centrifugal forces can be used to remove impurities. However, examination of various particles settling rate correlations shows that at smaller sizes, particle drag becomes a very important factor. Classification, based on differential settling rates, becomes impractical and some property other than density must provide the basis for fine coal cleaning. Froth flotation and agglomeration employ differences in surface properties to clean coal. These methods are very successful except that the oxidized surface of a pyrite particle is somewhat hydrophobic and will tend to be collected with the organic portion of the coal. Surface property cleaning techniques have not been very effective in rejecting sulfur, except for two-stage flotation.

Jan 1, 1984

By P. Rusin

Many oxide silver and molybdenum deposits remain undeveloped because chemical extraction yields poor recoveries or is environ-mentally unacceptable. Bio-reductive leaching of such ore samples at MBX resulted in high recoveries of silver and molybdenum. When baseline 3-day cyanide bottle roll tests were conducted on manganiferous oxide silver ore, 13.7% of the silver was extracted. In contrast, 86% of the silver was microbially solubilized into the organic growth medium by bio-reduction with 99.8% dissolution of manganese. A follow-up cyanide bottle roll test yielded an additional 8.5% silver recovery for a total recovery of 94.5%. Baseline 3-day acid bottle roll tests of the iron oxide molybdenum ore yielded 1.8% moly. However, bio-reduction solubilized 93.3% of the moly into the growth medium. An additional 0.3% moly was recovered during the follow-up acid bottle roll test. Microbial treatment of refractory oxide ores with bio-reductive bacteria resulted in higher recoveries of silver and molybdenum than conventional chemical leaching. The bioleaching process occurred at a near-neutral pH at ambient temperatures. The bacterial solubilization of silver and moly was achieved without the use of cyanide or sulfuric acid.

Jan 1, 1992

By A. Probst, N. Moores, J. A. Finch

In 1994, McGill University and INCO Ltd. (Sudbury operation) initiated the transfer of technology originally developed to detect levels in equipment ranging from flotation columns to thickeners. A conductivity probe was installed in a concentrate thickener to monitor the mud line and the solids load. The probe consisted of a vertical tube with 32 equally spaced electrode rings connected in pairs to give 31 conductivity cells. Conductivity was measured as a function of depth to produce a conductivity profile. From the conductivity profile, the mud line and the percent solids can be inferred. The probe was installed in October 1994, and it has been successfully detecting profiles since then. This paper includes a description of the incidents that occurred and the experiences gained during this technology-transfer process. Discussed is probe installation and startup; software modifications to accommodate both operating conditions and the needs of the operators; and calibration procedures to adjust to changes in performance as a consequence of long-term use. Also included are preliminary observations of the still-in-progress last stage, i.e., signal interpretation and use to facilitate operation, particularly by providing early reaction to upstream disturbances.

Jan 1, 1999

By Joel Lööw, Johan Larsson, Stig Vinberg, Malin Mattson Molnar, Mats Jakobsson, Jan Johansson

The mining industry is undergoing rapid transformation, driven by technological advancements, sustainability concerns and demographic shifts. This transformation will put more younger people in management positions. This study provides valuable insights into the leadership behaviors of younger and older managers within a large Swedish mining company, highlighting the importance of managerial experience and targeted training programs to foster effective leadership, particularly in the context of change management. The findings emphasize the need to create work environments that support managers to develop their leadership, contributing to improved employee well-being, operational efficiency, and adaptation to the changing demands of the modern mining sector.

May 1, 2025

By Takeshi Tanaka, Yasuhiro Komamura, Yuusaku Tominaga, Takayoshi Iwamoto

In order to assist better countermeasures for ventilation control in normal/abnormal condition of mine ventilation network in real time, branch relation table derived from a macroscopic characteristic of ventilation network is introduced in this study. The main results in this study are as follows; 1) One of macro characteristics of a ventilation network, as a relation between airflow rates in two branches chosen arbitrarily, is specified under the change of aerodynamic resistances in a branch. Airflow rate in a branch can be estimated by airflow rate in other branch changing aerodynamic resistance by using empirical formula. The empirical formula by computer simulation of the Horonai coal mine, Japan is considered to be a one-valued function with monotone or extremums. 2) A branch relation table shows the macro characteristics, mentioned above, of all the set of two-branch combinations in a network. Elements in the table give both information of control possibility range of airflow rate and total number of extremums in an empirical formula. 3) It is important that when aerodynamic resistance change in a branch is estimated by measuring airflow rates in two typical branches, the two branches should be chosen from branch combinations with monotonous relation in the branch relation table. 4) A flexible expert system to assist ventilation control in the specified branch in real time has been developed by using a branch relation table for a ventilation transfer diagram of the specified branch, such a coal face and an advancing face. A fuzzy reasoning is utilized in the recognition of the safety factor, methane concentration, in the system. And when conviction degree in recognition for methane concentration at the specified branch is too low, the system searches for other branch combinations in the branch relation table stored in the system, to use other ventilation transfer diagram of the specified branch. When a needed ventilation transfer diagram is not stored in the system, the expert system asks automatically the ventilation simulation from other computers linked to the main computer automatically. The system repeats consultation until conviction value of safety in the specified branch approached

Jan 1, 1993

By W. L. Price

Since first introduced in the United States in 1964, rail mounted bucket wheel stacker-reclaimers have gained wide acceptance by users. The coal burning power plant group has adopted this new storage tool most quickly. The actual history is traced in this area in some detail. Installations in phosphate and steel mill ore storage and a listing of present users are included.

Jan 1, 1969

By Vern Miller

The Bureau of Mines developed a detector for controlling sorting devices to separate the copper-bearing fragments from the barren portion of Michigan native copper and western porphyry copper ores. A successful sorter could be used to preconcentrate the ore and eliminate costly hoisting or hauling of waste. An induction balance unit was developed and used in sorting tests on crushed sized -1+1/2-inch (-2.5+1.3-cm) ores from the Kingston (0.9 pct CU) and Centennial (1.6 pct Cu) mines of Upper Michigan. Concentrates of 4.0 pct and 7.5 pct Cu, respectively, were obtained at recoveries of 85 and 80 pct of the copper in the feed. Eighty percent of the sorted ore was rejected as tailing. Sorting larger fragments improved the separation efficiency. Tests on -4+2-inch (-10+5-cm) sized Kingston (1.6 pct Cu) and Centennial (2.1 pct Cu) ore samples yielded concentrates of 4.3 and 4.5 pct Cu, respectively, with corresponding recoveries of 92 and 91 pct. About 60 pct of the sorted ore was discarded as tailing. Porphyry copper sulfide ores also responded to electronic sorting but at a lower separation efficiency. Sorting response was affected by the degree of segregation.

Jan 1, 1976

By W. E. Cobb

The financial implications of environmental liabilities are becoming staggering, particularly for mining companies. The Environmental Protection Agency's (EPA) Record of Decision (ROD) list for Superfund mining sites has some pretty hefty financial commitments, such as the $10 million operable unit remedy for the Yak Tunnel at California Gulch (in Colorado) or the $40 to 60 million remediation at Bunker Hill (in Idaho). These costs are driven by the large volume and areal extent associated with historical waste management practices at mining sites. (It's difficult to have a low-cost remedy for a 20-square-mile site.) Unfortunately, there are other ways of generating environmental liabilities besides Superfund, such as non-compliance with Clean Air Act provisions, stormwater permits, or National Pollutant Discharge Elimination System (NPDES) permits. In the last 2 years, EPA has increased enforcement in its regulatory programs, which has resulted in increased fines and criminal actions. Leaders in other industries (primarily the chemical and manufacturing industries) are viewing environmental liabilities as a strong motivator to select engineering approaches carefully based on technical, legal, economic, and philosophical perspectives. Industry interest in waste minimization programs comes from the concept that it is economically advantageous not to create waste in the first place. Waste minimization programs typically balance increased front-end capital investment with the minimization of potential long-term environmental liabilities as a way to achieve the lowest total-or life-cycle-cost. A side benefit of waste minimization programs is that they tend to improve overall regulatory compliance. Waste management practices are also becoming philosophical, as evidenced by a May 11, 1992, Business Week article: Companies that incorporate innovative thinking on sustainable development will do more than clean up or prevent their own pollution. They'll make and distribute a product more efficiently than ever, worry about its lifelong environmental impact, plan for recycling, and get their suppliers on the bandwagon. This type of approach will require a new mind-set, new tools, and adjustments throughout the organization. A key aspect of waste minimization or life-cycle waste management programs is the incorporation of environmental costs into economic analyses that compare various waste management alternatives. However, the incorporation of environmental costs into an economic analysis can be more difficult than initially thought. As noted above, new tools-or even a new toolbag-are needed, such as new accounting methods that track and assign the true lifetime environmental costs of a particular product. One piece of the new toolbag is life-cycle cost analysis, which is discussed in this paper. To simplify the discussion, this paper looks at the total costs associated with a given mining site. The concepts presented in this paper, however, can be applied to any mine waste management decision. The ultimate extension of life-cycle costing, as presented in the Business Week article, is to include the potential environmental costs throughout the life of a metal. At this point, I am perplexed on why, let alone how, to include the potential downstream environmental costs (i.e., the costs associated with smelting, manufacturing, use, and recycle or disposal) throughout the life cycle of mined copper, lead, or zinc.

Jan 1, 1992

By S. C. Howell

The mining of taconite, to provide feed for a processing plant, requires that the flow of material continue uninterrupted. This means first, that the crude must be of a size acceptable to the primary crusher in order to reduce the delays caused by plugging the crusher with chunks. Secondly, elimination of oversize in the pit will reduce costs of all wear parts used in the mining and processing of taconite. Savings in wear parts is readily recognized in dipper teeth, bases, buckets, truck boxes, and crusher parts, both primary and secondary. During the early days of taconite mining, it was soon recognized at reserve mining company's Babbitt operations that experience in mining other ores was not always (or ?necessarily??) Applicable to excavating taconite. This was especially true in drilling and blasting. Blasting of small tonnages in single or double rows simply filled the pit with scattered chunks and provided very shallow banks for shovel loading. It also created problems for the jet piercers, since all drilling had to be performed in fractured areas. Drilling efficiency suffered and costs were extremely high. Shovel and truck efficiencies were also low and again costs were high. A high percentage of secondary breakage was required. This necessitated the use of numerous man hours to jackhammer holes in chunks, preparatory to loading and blasting. After the chunks were reduced, bull- dozer and grader hours were needed to pile the taconite for acceptable shovel loading.

Jan 1, 1968

By Gabriel K. Nzulu, Lars Hultman, Per Eklund, Martin Magnuson, Abu Yaya, Prosper M. Nude, Hans Högberg

Pyrite is the most common among the group of sulfide minerals in the Earth and abundant in most geological settings. This gangue mineral in association with garnet, hematite, magnetite, and other sulfide minerals acts as an indicator mineral in the Kubi concession of the Asante Gold corporation in Ghana. X-ray diffraction (XRD), air annealing in a furnace, energydispersive x-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS) were applied to investigate the crystal structure, identify individual elements, permanence, transformation, and chemical/electronic properties of such pyrite. The study aims to identify individual elements and to gain an understanding of the surface reaction mechanisms, as well as the properties of precipitated pyrite particles observed during the hydrothermal formation of the ore deposit. XRD shows that pristine and annealed samples contain some hematite and quartz besides pyrite. Results from air annealing indicate that the relationship between pyrite and hematite-magnetite is controlled by temperature. EDX reveals that the sample has O and C as contaminants, while XPS in addition reveals Ba, Au, P, Al, and N. These elements are attributed to pyrite that bonds metallically or covalently to neighboring ligands/impurity minerals such as oxides, chalcogenide sulfides, as well as the gangue alteration minerals of magnetite and hematite in the pyrite sample. These findings suggest that during the hydrothermal flow regime, pyrite, pathfinder elements, and impurity minerals/metals were in contact with quartz minerals before undergoing hematite transformation, which thus becomes an indicator mineral in the Kubi gold concession.

Feb 27, 2024

By K. F. Unrug

An overview of the history of mining technology, both past and present, shows that some of the new concepts being successfully applied have changed the reserve categorization and are having an overall impact on production. Past coal mining operations in the eastern coal fields, and especially in Appalachia, extensively utilized stripping with the predominately applied contour method. As a result, vast mountainous areas have abandoned benches left behind by past mining operations. While thicker seams previously stripped were usually mined by underground or mountain top removal methods, thin seams beyond technical or economical limits were left intact after contour mining had reached the ultimate height of the wall. These thin seams quite often contain high BTU, low ash and sulfur coal that makes them attractive for a secondary recovery due to the market requirements. Secondary highwall recovery has obvious potential and is economically attractive; however, with the present state of industrial experience and lack of analysis of site data, a trial and error approach is used by operators.

Jan 1, 1983

By Bernard A. Kilgore

Kaolin is a hydrated aluminum silicate mined primarily in middle Georgia along the "fall line", the location of the coast line in prehistoric times. It is used extensively as a filler for paper, insecticides, tires, plastics, a pigment for paints, as a coating for fine gloss paper, and for high grade ceramic products, such as catalytic converters. During its journey from the open pit mine to its final use, kaolin takes many forms, and must be handled in many different ways. The purpose of this presentation is to follow kaolin through its process and briefly describe some of the methods Georgia Kaolin Company, one of the world's largest kaolin producers, uses to handle and convey its product and some of the peculiarities involved.

Jan 1, 1983

By H. Vigil Fernandez, G. Peach

The Musaimeer pump station and outfall project located in Doha Qatar, was designed to collect and manage ground and stormwater and then discharge the treated waters offshore. The project constructed a long outfall tunnel using an EPB TBM with segmental lining, each tunnel ring being 1.35 m in length with an internal diameter of 3.7 m.. The diffuser structure was a 6-arm structure, measuring 294m by 40 m connected to a central manifold in turn connected to the TBM constructed tunnel via a riser shaft drilled from an off-shore barge. This technical paper will discuss the planning, methodology and construction practices employed to connect the TBM tunnel to the diffuser structure 10.2 km offshore.

Jun 13, 2023

The Mine Safety and Health Administration (MSHA) has conducted studies to evaluate dust control technologies on deep cut continuous mining sections. These surveys have been conducted in different mines using various mining methods, face ventilation systems and dust control systems. The surveys typically consist of respirable dust sampling combined with a time study of mining activities. Measurements of dust control and operational parameters are also made. Critical elements identified for controlling respirable dust in deep cut mining systems include controlling intake dust, dust collector capacity, face ventilation quantities and velocities, positioning of workers, work practices and selection of equipment. This paper discusses how the dust surveys are conducted in deep cut mining sections and how these surveys are used to identify specific dust generating sources.

Jan 1, 1999

By S. Ford

The introduction of recent advances in molecular biology into the field of microbial ecology has made available a powerful set of analytical tools for dissecting the structure of microbial communities in natural environments. The use of these approaches, many of them based on DNA-DNA hybridization enables the researcher to assess the occurrence of specific DNA sequences among the natural bacterial flora (Ford and Olson 1987). These techniques promise to have wide application as tools for monitoring the spread of introduced microorganisms (Trevors, 198'): Ford and Olson. 1987) and have been used to examine the response of bacterial communities to environmental contaminants and stressors (Barkay and Olson. 1986. Olson and Ford. 1986. Olson. Ford and Lester 1987) The occurrence of heavy metal resistance among microorganisms has been discussed as a possible tool for the detection of pathfinder elements employed in mineral exploration (Olson and Barkay 1986). In addition, the occurrence of heavy metal resistant bacteria may be utilized in protocols for assessing the occurrence and biological impact of contamination occurring as a consequence of mining operations. In this context the use of DNA hybridization technology enables the investigator to directly quantify the number of heavy metal resistant bacteria by the use of genetic probes specific for those resistance genes. The implementation of a strategy for detection of heavy metal resistance genes by hybridization technology is dependent on the availability of data on the genetic systems which encode resistance The availability of extensive DNA sequence data on mercury resistance genes (Brown et a11986. Barrineau et al 1984) has lead us to use gene probes specific for mercury resistance within natural bacterial populations as a model system for investigating the response of these bacterial populations to the occurrence of mercury In the environment.

Jan 1, 1988

By N. S. Margaris

The vegetation of Mediterranean ecosystems is distinguished by its resistance to adverse environmental conditions, and that is the reason for examining the possibility of growing species of this flora in waste disposal sites (WDSs). The survival and growth of vegetation established at a waste disposal site is dependent to a large extent on the qualitative and quantitative characteristics of the material used in the final soil cover. In the Ano Liossia WDS, where extensive remediation work is under way, three areas were examined, which met certain criteria in relation to the age of the underlying waste and the existence of impermeable material in the final soil cover. Laboratory analyses have determined soil parameters and nutrient and heavy metal content. Alongside this, at all three sites a network has been installed to monitor the qualitative characteristics of the gaseous phase of the soil cover material. The results showed the existence of a soil material containing few nutrients and the prevalence of oxygen-poor conditions, accompanied by large concentrations of CH4, CO2 and H2S, at depths of up to about one meter.

Jan 1, 2002

By Norman R. Paterson

In November 1980 a combined airborne electro-magnetic (INPUT.) and magnetometer survey was conducted by Questor Surveys Limited in the State Line Area, Colorado-Wyoming. The survey was the result of discussions over a prolonged period between the authors and various investigators of the State kimberlite occurrences. As a result of these discussions and literature studies, it was decided that airborne geophysical methods would be potentially useful in the exploration for new kimberlite occurrences. The survey was designed by Paterson, Grant and Watson Limited and conducted by Questor Surveys Limited over an area in which more than 15 kimberlite bodies were known and on some of which ground geophysical surveys had been conducted. The survey was designed primarily to determine the airborne electromagnetic and magnetic responses of the known occurrences and to deter- mine whether these responses would be detectable under similar conditions in other parts of the State Line District and elsewhere.

Jan 1, 1984

By Yashar Pourrahimian, Roberto Noriega

Truck fleet dispatching plays a crucial role in reducing operational costs and fulfilling operational targets in open-pit mining operations and is subject to large uncertainty arising from the operating cycles of trucks and loading equipment. This paper proposes a reinforcement learning-based truck dispatching system. Reinforcement learning is a machine learning area that deals with learning an optimal sequential decision-making strategy in an uncertain environment. An open-pit load-and-haul simulation is developed that also captures the truck movements and interactions in the shared road network, and a Neural Network is successfully trained to suggest truck dispatching decisions in a real-time manner.

Jun 25, 2023

By J. D. Miller, C. L. Lin

"The use of 3D X-ray tomography analysis for plant-site characterization of coarse particles at a sampling rate of about 3 kg/min for particles ranging in size from 150 mm to 1 mm at a voxel resolution of about 150 µm is now possible. This is quite a significant advance in X-ray tomography technology and promises to be useful for plant-site coarse particle characterization—size, shape, composition, density, texture, grain exposure and mineral liberation—with a response time of minutes after receiving the sample. This paper discusses applications in the mineral industries, including the coal industry, aggregates industry, metal mining and the processing of industrial minerals.IntroductionPlant-site characterization of coarse particles at coal preparation plants, crushed stone/aggregate plants and mineral processing plants is needed to improve plant capacity, product quality and/or process efficiency. Not much online coarse particle characterization is being done at these plants. Only some limited information regarding particle size is obtained online from reflected light images using analyzers such as the OPSA, Split and WipFrag™ analyzers. Even the laboratory analysis of coarse particles has been difficult because of the large amount of sample required to ensure statistical significance of the results. During the past several decades, laboratory 3D characterization of particles from energy and mineral resources by X-ray tomography has been demonstrated and used to good advantage (Miller and Lin, 2004, 2009).Three-dimensional X-ray tomographic analysis has its origins in the medical services industry, where it is used to provide internal images of the human body. It has since been developed for nonmedical applications as well (Banholzer et al., 1987). Figure 1 shows a schematic diagram of the cone-beam geometry micro-CT system. In our case, X-rays from a microfocus X-ray generator are partially attenuated by the sample (a packed bed of particles) that is made to rotate in equal steps in a full circle about a single axis of the particle sample. At each rotational position, the surviving X-ray photons are detected by a planar two-dimensional array (image intensifier) large enough to contain the shadow of the specimen. These two-dimensional projection images are collected using conventional video technology. The video signal for each projection is then converted to a two-dimensional digital array by an image processing system. Finally, a threedimensional image is reconstructed from the collected set of projection images."

Jan 1, 2016