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By W. R. Sharp

The ability to target, delineate, excavate, and produce local resources is essential to the establishment of man's long-term presence in space. Many procedures and equipment utilized to mine resources here on Earth may be directly applicable on the lunar surface, while others may need extensive redefinition and development. This paper compares, for a lunar base, the alternative of burrowing into and below the lunar surface with that of surface mining. A conceptual underground mechanical excavator is presented.

Jan 1, 1991

By R. B. Dunn

Whilst coalmining in the United Kingdom has been synonymous with longwall mining practice there have been changes in recent times which have enabled not only an extension in the length of the face to be worked but also in the ability to extract both thick and thinner seams. Additionally the industry has taken a positive view in the extension of retreat methods of extraction applied for different reasons both to particularly thick and specially thin seams. To permit development of a flexible programme to meet these diverse needs, it has been necessary to design machinery along with mining systems specially suited to these requirements. In reviewing current UK thinking special emphasis is made on the extraction of thinner seams generally of higher quality coal at moderate depths with a commentary on some recent results.

Jan 1, 1979

By A. M. Anthony, A. Y. Atta, S. S. Magaji, U. Abubakar-Zaria

There are two major gold recovery methods: the hydrometallurgical technique, which employs cyanide solutions, and amalgamation method, which involves mercury (Hg). These methods present considerable health, safety, and environmental concerns. Past applications of alpha-cyclodextrin (α-CD) on gold scraps show that α-CD is not only inexpensive, but is also environmentally friendly. This research work used α-CD to recover gold from gold ores instead of gold scraps. The gold ore was sourced from Shanono gold deposit site Kano State,Nigeria. The gold ore was characterized by fire assay (FA) for the precious metal. The concentrate was digested with aqua regia (AR) for 24 h. Modified AR, where hydrochloric acid was replaced with hydrobromic acid, was used for the gold digestion due to the good match in molecular recognition between gold bromide ion (AuBr)− and α- CD in a second sphere coordination complex. The digestate was characterized using atomic absorption spectroscopy (AAS). Gold recovery using this technique is pH sensitive, and five pH values (2.0, 3.6, 4.0, 5.4, and 6.0) were investigated. FA analysis showed the Shanono gold ore deposit contains an average of 4.71 ppm of gold, AAS analysis showed highest gold recovery of 69% at pH 4.0, which is lower than recoveries from the metal scraps. This could be due to the presence of other gangue minerals closely associated with the ore. However, gold recovery using α-CD on Shanono gold ore has shown to have a higher yield of 69% compared to 35.5% yield obtainable by Artisan Small Scale Miners using mercury.

May 5, 2020

By D. S. Flett

Abstract. The commercial importance of hydroxyoximes as extractants for copper has given impetus to basic studies on the chemistry of metal extraction by these compounds. The discovery of accelerator compounds which produce catalytic effects on hydroxyoxime extraction rates has led to mechanistic studies of these rate processes. While these studies have highlighted the importance of interfacial chemical reactions in the extraction process, it is not yet possible to unambiguously describe the mechanisms of metal extraction in these systems or the associated catalytic effects. This paper reviews progress in understanding the mechanism of metal extraction by hydroxyoximes.

Jan 1, 1979

By K. S. Gritton

The U.S. Bureau of Mines has investigated methods for extracting metals from a variety of arsenic-containing smelter flue dusts. One proposed flowsheet includes a sulfuric acid leach, a cooling step to precipitate hydrated copper sulfate, and a reduction-precipitation of As2O3. Arsenic extractions greater than 90 pct were achieved, while copper extraction ranged from 50 to 85 pct under the conditions examined. Copper was removed from the leach solutions by crystallization followed by SO2 precipitation of arsenic which resulted in a 98 to 99.9 pct As2O3 product. Other metals, such as lead and zinc, were concentrated in the leach residue or in other byproduct streams for recovery of their valuable metal contents.

Jan 1, 1990

Laboratory testing by the Federal Bureau of Mines has shown that the removal of insoluble slimes using selective flocculation and flotation is a viable method for treating low-grade potash ores which have a high content of water-insoluble impurities. Results indicated that up to 85 percent of the insoluble slimes could be removed from sylvinite ore containing 5 percent water insolubles and 13 percent K20 using nonionic or cationic polyacrylamide flocculants and cationic, anionic, and/or nonionic collectors. Subsequent potash flotation recovered up to 88 percent of the potash in rougher concentrates containing 47 to 57 percent K20. Sizing and cleaner flotation of the rougher concentrates upgraded the products to 60 percent K20. Filtration of the insoluble slimes flotation concentrates recovered 87 to 0 percent of the brine. Flotation concentrate filtration rates were 7 times faster than the filtration rates of mechanically deslimed products.

Jan 1, 1977

By W. M. Cross

The use of fillers and reinforcements for plastics has increased considerably over the past few decades. For example, in the 1980's the average growth rate of filler use was 5.8%. [Katz and Milewski, 1987] Similar filler use growth rates occurred in the 1970's due largely to the increase in price of petrochemical starting materials for plastics. While filler use is still sometimes predicated on the cost benefits associated with their addition to the plastic, other mechanical and performance advantages associated with filler addition are being realized, and account for most of the increased usage. Plastic filler types are many and varied, and include both inorganic minerals/metals and organic compounds, with the former type being, by far, the more common. Common mineral fillers include oxides, including both natural and synthetic silica; carbonates, particularly calcium carbonate; clays such as kaolin; and silicates like mica and talc. It has been recognized that a number of factors influence filler performance, including particle size, shape, surface area, and hardness to name a few. In addition, the interaction between the filler and the plastic is of paramount importance as this interaction will determine the wettability, bonding and the adhesion between the two materials, and ultimately, the mechanical properties of the composite. Froth flotation has long been recognized as a viable process to separate different mineral types. [Leja, 1982] Prior to flotation the minerals are liberated from the ore by comminution. The mineral particle size range produced by this comminution process is typically between 300 and 10 microns. This size range is also typical of mineral fillers for plastics. The size similarity between mineral fillers and minerals concentrated by froth flotation is only one of many similarities that can be found.

Jan 1, 1997

By A. Juganda, F. WILSON, G.E. BOGIN, H. PINHEIRO, N. SANDOVAL, J.F. BRUNE

To evaluate methane explosion hazards in underground longwall coal mines, researchers at the Colorado School of Mines developed a computational fluid dynamics (CFD) model along with a 1/40th-scale, optically accessible, physical model of a longwall mining section. In this project, CFD models assisted in the design of the physical model to ensure specifications were met to accurately represent the scaling physics as well as to assist in narrowing the experimental matrix and identifying key locations for sensor placement to measure velocity, pressure and gas concentrations. This research will help develop strategies for methane monitoring to prevent methane ignitions and explosions in longwall coal operations.

Dec 1, 2022

By Robert R. Unterberger

The purpose of this paper is to summarize the research of the past sixteen years on three distinct methods of probing into solid rock. The first method is to use radar of the appropriate frequency. The second method is to use sonar. The third method is of recent vintage and uses techniques of nonlinear sonar also known as parametric sonar. The first two concepts, that of radar and sonar, are common to most people. Very few have heard of nonlinear sonar. Each of the probing techniques were investigated in order to overcome deficiencies in the former technique. Each has its advantages and disadvantages. It should be emphasized that all of these techniques for probing (or seeing) into rock are used in mines, and generally speaking not from the surface. Only in very special cases, such as certain very dry parts of Egypt or Peru, or, for example, the surface of the moon, will these probing techniques work from the surface. The reason for the development of these probing techniques has been to alert miners to possible hazards ahead of mining. Such hazards may be (1) old (unknown) boreholes connected with high pressure water zones above, (2) fractures that might connect to the Gulf of Mexico above the mine, (3) water-filled fractures that threaten the safety of miners, or (4) the discovery of dry faults ahead that can disrupt the planning of future operations.

Jan 1, 1983

By Daniel Lakovic

"Mining operations can create a negative environmental impact, especially when considering the tailings that are produced through the processing of ores. Tailings are finely grained residues that form sludges. The tailings are deposited into giant basins, or sludge ponds, where they create a burden on the environmentby limiting the use of processed water.Tailings are one of the most important environmental liabilities for mining operations because of their large proportion in relation to the ore mined — generally 90 to 98 percent. To get to the valuable minerals, mining companies must move large amounts of rock. The rock is ground and then treated, usually with the addition of chemical solutions and large amounts of water. The lower the concentration of the valuable resources, the greater the proportion of accumulated excavated material sludge.Sustainable tailings management requires responsible handling, making it one of the mining industry’s greatest challenges. The proper technology should include consistent control of the environmental risks and impacts, as well as a proper relationship with the communities that surround the mining operations.The tailings, which can remain partly contaminated with chemicals, are pumped into the large sludge basins, which are secured by earthworks. During the mining operations, the basins must be stable enough to withstand the pressure of the stored excavated material. The storage option is still used, but it has failed on occasion. And when it does, it increases the risks to the environment and binds the unused process water. The more complex the availability of fresh water required for industrial use and for human consumption and their economic activities — for example, farming and agriculture — the more complex the conflicts that have the potential to shut down mining operations. With modern separation technology solutions, it’s possible to process the sludge and recover the processed water. However, the responsible use of the water is critical. Therefore, mining companies must rely on technologies that allow for proper reclamation of the water, whether re-using in their own processes or treating it to return it to the environment."

Dec 1, 2018

By T. Skodack

This presentation will compare actual work site results for the loading and transport of shot rock for two major tunneling projects in North America. "SCARMAR" (the Canadian subsidiary of S & M Construction) is operating a rail bound Hagglund continuous gathering arm loader in combination with a Hagglund nine car shuttletrain system at the West End of Table Mountain on the B.C. Railway project near Tumbler Ridge, Canada. Al Johnson Construction is operating a Hagglund rubber tired continuous gathering arm loader in combination with haul trucks at the Rocky Mountain Pump Storage Project near Rome, GA. This paper will compare: 1) tunnel and ground conditions, 2) the total work cycle as it relates to mucking and haulage 3) efficiencies and related problems with the two systems 4) mucking and haulage rates 5) operating costs, and 6) recommendations for future large tunnel excavations. Manuscript not received in time for publication.

Jan 1, 1983

By G. M. Wilemon

The U.S. Bureau of Mines has conducted preliminary investigations on the leaching of phosphate ores obtained from deposits in the western United States using sulfuric acid (H2SO4) in the presence of methanol. Phosphate extractions in excess of 80 pct were obtained on an ore sample from Pocatello, ID. Initial leaching studies using the ore as received yielded extraction levels of approximately 35 pct. However, when the sample was ground for as little as 5 min in a rod mill, in methanol, then treated with HzS04, 82 pct extraction was achieved. The R2O3-P2O5 (R2O3 = Al2O3 + Fe2O3) ratio of the starting material was 0.11. Solubilized products after leaching exhibited an R2O3-P2O5 ratio of 0.02, which is well within desired limits. These results illustrate the potential of acid-alcohol leaching for recovering phosphate values from marginal-grade ores and as an alternative to methods involving current beneficiation techniques that yield lower phosphate recoveries.

Jan 1, 1992

By N. Damiano, C. Zhou, B. Whisner, M. Reyes

"The industrial Internet of Things (IIoT)—a concept that combines sensor networks and control systems—has been employed in several industries to improve productivity and safety. NIOSH researchers are investigating IIoT applications to identify challenges of and potential solutions for transferability of IIoT from other industries to the mining industry. Specifically, NIOSH has reviewed existing sensors and communications network systems used in U.S. underground coal mines to determine whether they are capable of supporting IIoT systems. The results show that about 40% of the installed post-accident communication systems as of 2014 require minimal or no modification to support IIoT applications. NIOSH researchers also developed an IIoT monitoring and control prototype system based on low-cost microcontroller Wi-Fi boards, to detect a door opening on a refuge alternative, activate fans located inside the Pittsburgh Experimental Mine, and actuate an alarm beacon on the surface. The results of this feasibility study can be used to explore IIoT applications in underground coal mines based on existing communications and tracking infrastructure. INTRODUCTION The nation’s approach to health and safety in mining has historically been reactive in the sense that health and safety regulations and mandates have traditionally been passed as a result of tragic mining accidents. An example of this is the Mine Improvement and New Emergency Response Act (MINER Act) of 2006, which was passed as a result of several mining accidents where tracking of and communications with underground personnel were severely limited. While this reactive approach has led to the development and implementation of highly impactful safety interventions and safety practices, there currently exists a technological revolution that can shift the paradigm toward a proactive approach based on preventative methods: Internet of Things (IoT). IoT is the network of physical objects or ""things"" embedded with electronics, software, sensors, and connectivity to enable that network to achieve greater value and service by exchanging data with the manufacturer, operator, and/or other connected devices [1, 2]. It should be noted that IoT has been defined from various perspectives, and hence numerous definitions exist in the literature. The apparent ambiguity of the IoT definition might be due to the fact that IoT is syntactically composed of two terms: internet and things. The first one pushes towards a network-oriented vision, while the second tends to put the focus on generic objects. The traditional internet can be viewed as an internet of computers —i.e., “things” connected to the internet are computers only. IoT “extends” the internet by allowing other generic things that are commonly found in our daily life, such as refrigerators and cars, to be interconnected via the internet, and thus creates a bridge between the virtual word and the physical world."

Jan 1, 2017

By Laszlo Valentyik

The wide scale acceptance of the heavy media separation is due to its simplicity and efficiency. The two most important variables of the process are specific gravity and consistency of the medium. The latter is a function of the settling rate of the media solids. The almost always present clay in the feed and conse¬quently in the medium acts as a stabilizing agent, and its optimum concentration varied between 3-4%.(1,2) Since polymers essentially perform the same function in oil well drilling muds - i.e. to suspend cuttings during drilling - as the fine clay in heavy media separation, this led to the investigation of whether polymers could be used in heavy media separation as supporting agents. During the first phase of the work, it was found that by the controlled addition of polymers, the stability of the heavy media increased without unduly increasing viscosity of the suspensions, thus yielding conditions for more effective and efficient separation. The results of the experiments were reported in a paper at the AIME Centennial Annual Meeting, March 1971.(3) This paper presents the results of the experiment carried out during the second phase of the work.

Jan 1, 1975

By C. E. Capes

The spherical agglomeration process provides an attractive method for the cleaning and recovery of fine coals in the form of compact oil-bonded pellets. In treating a washery effluent containing 50% minus 20 micron material by this technique, the slurry was first mixed under vigorous agitation with oil to deash and dewater the fine coal. The flocculated coal pulp was then formed into larger agglomerates on a modified balling disc. The operation of a semi-pilot scale process is described and an analysis of some of the operating and system variables is given. A semi-theoretical expression to predict the final agglomerate size under various conditions is derived and compared with the experimental data. Coal producers are faced with a growing requirement to clean and recover fine mesh coals. Greater mechanization of the extractive and preparation processes has resulted in finer-sized products containing larger quantities of associated foreign matter and preparation plant effluents contain quantities of fine coals which are potentially valuable. These losses will probably increase with the expansion of production and will require the development of effective disposal and utilization processes under pressure of the lack of adequate disposal areas, the enforcement of air and stream pollution laws, and the economic need to obtain the maximum yield of salable product(1)

Jan 1, 1970

By R. Pinksen

The IOC Mining and Operations Departments expressed an interest in reducing the amount of oversize material (>1.0 m x 1.0 m x 1.0 m; 39 inches x 39 inches x 39 inches) being produced and its subsequent downstream effects including in-pit sorting and reduction, damage to mobile equipment, and significant delays in the loading pockets and the primary crushers. To achieve this goal an oversize reduction project was undertaken by the mine and to date has significantly improved upon baseline measures. One key approach used to reduce the amount of oversize was the implementation of thicker emulsion. The introduction of a thicker emulsion provided more resistance to the forces created by dynamic water and reduces the infiltration of the emulsion into the cracks and fissures of the rockmass. Reduced amounts of oversize and more consistent fragmentation throughout the muckpiles has been a result. Additionally, a significant reduction in nitrates leached into the mine water discharge has been realized. To determine the effectiveness of the oversize reduction project, IOC used a of first-of-kind technology to assess fragmentation presented to the shovel at the digging face. A Digital Vision System (DVS) was installed on one of the shovels to capture images that were stamped with GPS locations. A large population of digital images were analysed to produce a robust fragmentation distribution baseline that was used as one of the mine key performance indicators (KPI). Changes to blasting practice were subsequently measured against the baseline KPI to assess effectiveness.

Jan 1, 2011

By Ross K. Digby

The Victorian Tunnelling Centre (VTC) has evolved its purpose from purely training workers, to a tunnelling industry education city. The VTC has now focused its activities on the areas of technology; education and training; applied research; and career education. were identied as the hus around which activities would e conducted to create a tunnelling industry education city. The VTC provides ustralias tunnelling industry with an education facility that not only provides laour training, ut enales the industry to come together to meet, participate in product launches, undertake research, work with new technologies and promote tunnelling careers.

Jun 23, 2024

By R. E. Snow

The analysis of ground water inflow and discharge from underground mines has received increased attention in recent years due to environmental issues which must be addressed under current state regulations for coal mining and processing operations. In particular, coal operators must assess the probable hydrologic consequences associated with mining activities, and must plan for mine water handling during operation and following completion of mining. The prediction of ground water inflow rates with future mine development allows preparation for potential operational problem and identification of inflow reduction methods. Similarly, evaluation of mine discharge rates is necessary to address potential long-term acid mine drainage (AND) concerns. As part of mine discharge analyses, methods. to control seepage and AMD can be considered. The objective of this paper is to discuss the practical applications of mine inflow and discharge analysis, describe the typical flow components, outline the procedures necessary to perform the analysis, and illustrate the modeling procedures and potential results of mine inflow and discharge predictions.

Jan 1, 1990

By J. Grubb

"The undertakings described in the paper titled “Study on correlation of quantified coal rank with self-heating temperature” by Wang and Luo in the November 2015 issue of Mining Engineering (Wang and Luo, 2015) are mathematically sustainable and an acceptable extension of work performed by Smith and Lazzara (1987) for the U.S. Bureau of Mines. The paper is not an accurate explanation of the currently accepted leading practice for determining the propensity of a coal seam for spontaneous combustion. The paper could lead a practitioner to an oversimplified conclusion on how to determine the propensity of a coal seam to spontaneously combust.The spontaneous combustion of coal is a complex and not fully understood reaction. What is understood is that many more factors other than selfheating temperature (SHT) and coal rank are required to sufficiently evaluate the risk of spontaneous combustion in a particular coal seam. A superficial assessment can lead to an improper response to the risk. Some statements on the next steps through an appropriate literature search would have made the authors’ conclusions more credible.The SponCom 2.0 software, updated by the National Institute for Occupational Health and Safety (NIOSH) in 2011, provides a path for evaluating the susceptibility of a coal seam to spontaneous combustion. In addition to proximate and ultimate analyses to establish coal rank, and therefore an estimate of SHT, the program includes the history of heatings, friability, seam thickness, overburden thickness, rider seam presence, pyrite presence, face and butt cleat densities, geothermal source presence and other geological features in the assessment. Mining conditions including floor heave, rib sloughage and rate of advance are also assessed to conclude a propensity for spontaneous combustion."

Jun 1, 2016

By J. Marsden

Lift height, overall heap height and climate all play an important role in determining precious metals leaching rates, recoveries, operating costs and capital cost requirements for heap leaching operations. The effects of these factors are not easy to predict from testwork, and this can result in unexpected delays in metal production, lower recoveries than expected and higher capital and operating costs than necessary. This paper investigates the economic impact of lift height, overall heap height and climate on heap leaching and provides criteria to assist in the design and operation of leaching facilities. Descriptions of three heap leach operations in the western USA are provided to support the discussions and conclusions.

Jan 1, 1995