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By D. N. Tallman

The Bureau of Mines has completed 4 yr of deep-bed filtration research comparing the efficiencies of granular magnesium oxide (MgO) and conventional filter sand in single- and dual-medium filters when filtering mineral-processing and mine waters. Bench and field evaluation tests were conducted using water types ranging from synthetic suspensions of asbestos, kaolin, metal hydroxides, and milled sand to process waters from magnetite beneficiation, iron ore flotation, granite cutting, and a steel mill. Even though the turbidity reductions were similiar, MgO filters were found to be advantageous when filtering water pretreated with alum because the volume throughput before breakthrough (turbidity > 1 NTU unit) was much more for the MgO filter than for the sand filter. Reduced head loss owing to the greater porosity of the MgO filter beds is potentially the most beneficial advantage in employing MgO as the filter medium, especially when filtering water pretreated with polymer flocculants. Granular MgO (periclase) is durable and can be backwashed Like sand. It is compatible with anthracite in a dual-medium filter and apparently is not poisoned by dissolved metals in the process water. No single solid-removal mechanism could be identified for the improved filtration observed with granular MgO.

Jan 1, 1987

By Vijaya Bhushan Rao, Jason Redgers

A substantial lifestyle destination in the United Arab Emirates, in the Emirate of Abu Dhabi comprising of 1315 villas, town houses and non-residential leisure facilities is built over an area of 280 hectares of former mangrove areas, natural sands and reclaimed lands. Large-scale subsoil investigations including field and laboratory testing carried out dividing the entire site in to 7 clusters. This investigation revealed alternating layers of loose sands and silty clays within the load influence zone of planned foundations, showing susceptibility to excessive settlements. Therefore, ground improvement works were undertaken using a combination of stone columns, Rapid Impact Compaction (RIC) and excavation and replacement of soils plus a 0.4m thick load transfer platform. This was necessary to limit the settlements, increase-bearing capacity and prevent long-term settlements. 30 no’s of full-scale Zone Load Tests, ZLT were carried out each for a duration of 30 days in order to ascertain the anticipated long-term settlements in the clay layers. In addition, further testing of electrical cone penetration tests, CPT, and Plate Load Tests, PLT. The use of Priebe and Asaoka’s observational procedure were applied to predict the final settlements and the use of back-analysis from the 30 days Zone Load Tests, ZLT results to establish the site-specific consolidation parameters in clay layers to optimize the design and ground improvement works.

Sep 8, 2021

Tailings management trade-off studies are done for all mining projects. There is wide variability in these studies as their approach, details and outcomes are determined by the experience and focus of the project team. While some of these approaches may consider the whole life cycle of the project others may focus only on capital and operating costs and direct environmental impacts. A complete life cycle approach is not standard practice. This paper describes an approach to implementation of formalised life cycle assessment (LCA) following ISO 14044 to tailings management trade-off studies. The paper describes the implementation of the methodological framework for the LCA, ie goal and scope definition, life cycle inventory analysis, life cycle impact assessment and life cycle interpretation. This standardised approach to implementing tailings management trade-off studies following the LCA approach will contribute to the state-of-the-practice in sustainable mine development.

Jan 1, 2009

By J Greberg

This paper discusses the use of simulation in the mine planning process. A case study on the Newcrest Cadia East project is presented, and the challenges and possibilities for using simulation as a tool for mine planning and scheduling is discussed.The simulation study presented in this paper was performed during the project’s prefeasibility stage, and focused on the planning and scheduling of the development of panels in the future mine. The Cadia East project will be the largest underground operation in Australia and the first using panel caving. Simulation was used in order to optimise the development of panels; it was mainly used in order to verify the plans for the development process and allocate resources in an optimal way. The work was performed as an iterative process and adjustments to the plans were made according to simulation results. Bottlenecks were identified and different scenarios were tested.The results from the simulation study shows how different operational constraints affect the planned development process and how changes in priorities can be necessary in order to maintain a high development speed. Furthermore the study shows how changes in planned mine layout requires changed strategies, and how this was solved using the simulation tool.In this paper the authors critically discusses the use of simulation in mining operations: what are the limitations and challenges of using simulation as a tool for mine planning and scheduling, what are the benefits, and what do we aim for in the future?

Nov 22, 2011

By I. A. Tinto

"Labrador City is located in the southwestern portion of Newfoundland-Labrador, approximately 965 kilometers north-east of Montreal. The mine and beneficiation complex of the Iron Ore Company of Canada, known as the Carol Project, is situated 535 metres above sea level in a climatic region characterized by cold winters and short, cool summers.HistoryThe Iron Ore Company of Canada commenced work in the area in 19 4 9' however, it was not until 1958 that the decision was made to proceed with mining operations. The ore body consists of Specular Hematite (Fe203) and Magnetite (Fe304) with small quantities of Limonite and Geothite. The average grade of the ore bodies is 39% iron.The mining facilities, crushing plant, and concentrator were in operation by the early part of 1962. In the summer of 1961, a decision was made to build a pelletizing plant adjacent to the concentrator. This plant was designed, erected and placed in operation during 1962 and the first half of 1963. Since the completion of the pelletizing plant, additional expansions to both the pellet plant and concentrator have taken place in 1967 and 1973. Today, the Carol Project has the capacity to produce 20 million tonnes of concentrate from which 10.5 million tonnes of pellets can be produced.The period 1980-85 spans a period of energy crisis, world-wide recession, and a consequent re-structuring of the North American steel industry as it struggles to survive in an arena of excess world steel making capacity, government subsidized industries, and the increasing competition from overseas and from developing countries.The media headlines over the past few years echo the woes of the industry and the strategy plans for survival of the fittest. Today's buzz words are foreign competition, steel import quotas, joint ventures, employee participation, work rules, quality, productivity, and state of the art technology."

Jan 1, 1986

By P. Langlois, G. Labonté, J. J. Barrett, J. Holmes

"The Voisey’s Bay mill processes a high-grade pentlandite and chalcopyrite ore in a largely pyrrhotite/troilite matrix. From 1994 to 1997, circuit development focused on making a 14% nickel concentrate. When flowsheet development resumed in 2001, the target grade was raised to 20% ni. initially triethylene tetramine and sulfite pyrrhotite depressants were used in a lime circuit, but by recycling process water and the contained thiosalts, the required nickel grade was made without depressants. construction of the mill was fast-tracked, with start-up in september 2005. ramp-up was faster than other recent nickel installations, with tonnage being limited by concentrate dewatering due to higher-thanexpected ore grades.RÉSUMÉ l’usine de traitement de Voisey’s Bay traite un minerai à teneur élevée en pentlandite et chalcopyrite dans une matrice formée surtout de pyrrhotite/troïlite. De 1994 à 1997, le développement du circuit ciblait la production d’un concentré à 14 % de nickel. lorsque le développement du schéma de traitement a été repris en 2001, la teneur cible a été élevée à 20 % de ni. initialement les déprimants triéthylènetétramine et sulfite de la pyrrhotite étaient utilisés dans un circuit à la chaux; cependant, en recyclant l’eau du procédé et les sulfosels qui y sont contenus, la teneur en nickel a été atteinte sans utilisation de déprimants. la construction de l’usine de traitement a été accélérée et elle a démarré en septembre 2005. la mise en opération a été plus rapide que pour d’autres installations récentes de nickel; le tonnage traité étant limité par le séchage du concentré en raison des teneurs de minerai plus élevées que prévu.INTRODUCTIONnickel was discovered on canada’s east coast in the vicinity of Voisey’s Bay, northern labrador, by chislett and Verbiski (Higgins, 2011) while working for Diamond Fields resources in 1993. The ovoid deposit was subsequently delineated in the winter of 1994–1995. By the end of 1995, the ovoid had been well explored, and at that time was thought to have a reserve of at least 30 million tonnes (Mt), with an average grade of 2.83% ni and 2.0% cu (naldrett, singh, Krstic, & li, 2000). Drilling to the east of the ovoid indicated the presence of significant mineralization. in June 1995, inco limited bought a 25% share in the Voisey’s Bay nickel company (VBnc), which was a subsidiary holding company set up by Diamond Fields. inco also bought 8% of Diamond Fields and negotiated the right to sell all the nickel produced from VBnc for 20 years as part of this agreement. in april 1996, inco bought Diamond Fields and acquired the remaining 75% of VBnc shares."

Jan 1, 2017

By W. T. Reid

A shortage of anthracite for home heating indicates the necessity of using other fuels for this purpose; low-volatile bituminous, or "soft" coal is the most feasible supplementary fuel, either burned alone or when mixed with anthracite. Comparison of Bituminous Coal and Anthracite Whereas anthracite is clean, burns without smoke, and requires little attention, bituminous coal is dusty, tends to burn with a smoky flame, and forms coke in the fire pot that must be broken up to maintain a continuous high output of heat. When properly fired, however, bituminous coal responds more quickly than anthracite to changes in damper settings and consequently can supply more heat in a short time. It is generally less expensive and usually contains less ash than anthracite.

Jan 1, 1943

By Madan M. Singh

With the current emphasis on ecology, safety, and conservation of natural resources, some consideration should be given to methods of mining that reduce surface damage, make the mining of coal less hazardous, and allow exploitation of a larger percentage of the coal in situ. One method that can be helpful toward attaining these objectives is the use of packing or stowing. Stowing involves the replacement of the ore that has been removed by waste material obtained from within the mine or elsewhere. Evidently, it would be most beneficial if this waste for packing were available from the mine being worked, but generally this is not possible. If complete stowing is adopted, it is necessary to bring in packing material from other sources. Stowing tends to reduce surface subsidence, but not eliminate it. It enhances roof support and curtails accumulation of methane in the gob, making the mining operations safer. It may also allow one to obtain a larger amount of coal. Currently, in the United States, a substantial amount of coal is left in place as pillars, in the hope that it will support the overburden indefinitely. Some of these could be extracted with stowing. The mining of thick, steep, or contiguous seams would also be facilitated.

Jan 1, 1974

By H. C. Fowler

Hydrogen sulphide associated with the gasps and vapors from certain crude oils now produced in the United States has forced a serious health and safety problem upon the petroleum industry. Although the presence of hydrogen sulphide in or occurring with Mexican crudes has been known for some time, it was not until recently that crude oils which give off poisonous amounts of hydrogen sulphide have been produced to any extent in the United State. The injurious effects of this poisonous gas were first recognized by the refiners along; the Atlantic and Gulf Coasts upon receiving shipments of crude petroleum from Mexico. The problem of combating the hazards of the gases and vapors given off by this petroleum become more important as the use of Mexican crude increased. In 1925, the Bureau of Mines and Public Health Service under cooperative agreement with the American Petroleum Institute, studied the causes rend effects of hydrogen sulphide poisoning. Bureau of Mines Bulletin 2312 is report of this investigation, and although written with special reference to refineries, it nevertheless contains much information that is of value to the producer of petroleum.

Jan 1, 1927

By R. J. Good

It is well known that the elimination of impurities such as iron pyrite, shale, clay, silica, etc., from coal, by floatation [Sun, 1954; Aplan, 1983] and selective oil agglomeration [Keller and Burry; 1990] depends on the fact that coal is hydrophobic, and the impurities are hydrophilic. The water contact angle has long been used to evaluate the hydrophobic nature of coal, first by Brady and Gauger (1940), who demonstrated that the contact angle of water on coals increases with rank, and passes through a maximum at about 88% carbon. Brown (1962) found that the contact angle of coal decreased with increasing ash content. Sun, and also Aplan, have reported a direct relationship between values of the contact angle and rank, and have related the contact angle to coal floatability. Horsley and Smith (1951) first demonstrated that the captive bubble contact angle may be used to characterize the hydrophobicity of a coal containing more than 80% carbon DAF, while Parekh and Aplan (1978) have shown that the sessile-drop technique may be used to evaluate the hydrophobicity of coal of any rank.

Jan 1, 1992

By Carlos Enrique Arroyo Ortiz, Jadir Pedro Alves

This paper presents some of the results obtained during the research work about the use of technologies and digital transformation in the process of rock drilling in open pit mines. The use of automation presents itself as a disruptive factor and a driver of improvements that provide sustainability in rock drilling. Seven main operational parameters were utilized to combine measurement while the drilling (MWD) with other information generated by the equipment during hole drilling, in six different lithologies in an iron mine, located in the central region of Minas Gerais in Brazil. Adjustments and corrections were made to the data collected in order to minimize external influences other than the rock itself, to ensure the effectiveness of the analyses. Finally, we sought to compare the performance of the drilling process in manual and automatic operation modes. Thus, making it possible to show the efficiency and impact on the sustainability of rock drilling operations in open pit mines.

Feb 6, 2023

By Javad Sattarvand, Amin Moniri-Morad

Predicting equipment failure behavior plays a critical role in providing a safe operation. Although various reliability evaluation methods are available for estimating failure behavior profiles, these approaches are based on mathematical formulation, leading to actual operation simplification and improper estimation of failure trends. This study proposes a discrete-event simulation (DES) approach to model fleet failure behavior. This approach can model the maintenance strategies in multi-component systems with minimum simplifications. In this regard, the first step was to collect a historical failure time dataset (e.g., the time between failures). Then, the DES model is established to predict the severity of failure events and design maintenance strategy considering actual operation circumstances. Afterward, the maintainability analysis was performed to estimate equipment downtime and availability. The achieved results showed that the system availability was about 85%. Also, the findings demonstrated that the DES could efficiently predict the equipment failure behavior using various stochastic events.

Jun 25, 2023

By D. R. Tweeton

The U.S. Bureau of Mines, the University of Arizona, Sandia National Laboratories, and Zonge Engineering and Research Organization, Inc., conducted cooperative field tests of six electromagnetic (EM) geophysical methods to compare their effectiveness in locating a brine solution simulating in situ leach solution or a high-conductivity plume of contamination. The brine was approximately 160 m below the surface. The testsite was the University's San Xavier experimental mine near Tucson, AZ. Geo- physical surveys using surface and surface-borehole, time-domain electromagnetic (TEM) induction; surface controlled-source audiofrequency magnetotellurics (CSAMT); surface-borehole, frequency- domain electromagnetic (FEM) induction; crosshole FEM; and surface magnetic field ellipticity were conducted before and during brine injection. The surface TEM data showed a broad decrease in resistivity. CSAMT measurements with the conventional orientation did not detect the brine, but measurements with another orientation indicated some decrease in resistivity. The surface-borehole and crosshole methods located a known fracture and other fracture zones inferred from borehole induction logs. Surface magnetic field ellipticity data showed a broad decrease in resistivity at depth following brine injection.

Jan 1, 2010

By Wadaw Cybulski

The problem of coal dust explosions: Basic information about the explicability of coal dust: Main parameters of the explosibility of coal dust; Main parameters of the explosibility of coal dust; Limit explosibility of coal dust and its dependence upon the basic parameters: The effect of the initiator of the explosion-on-the explosibility of coal dust: The dependence of the course of an explosion upon the distribution of coal dust in the workings, upon the dimensions of the workings, the length of zones, the direction of the development of explosions and upon the content of firedamp in the air of the workings; Con-sequences of coal dust explosions; The ways of suppressing the danger of coal dust explosions; Stopping the developed coal dust explosions; The explosibility and explosions of lignite dust of xylite structure

Jan 1, 1975

By Sam S. Taylor

"INTRODUCTION This report deals with a comparatively simple application of some of the engineering principles involved in the evaluation, installation, and operation of air- or gas-injection projects and well-clean-out and repair methods to increase the producing rates of oil wells in partly depleted pools during the war. The methods suggested for developing gas-injection projects take into consideration that in general no new wells will be drilled because of wartime restrictions of equipment and manpower and that only existing wells and second-hand machinery will be used. Because air will be employed as the injection medium in secondary-recovery operations where natural gas is scarce and expensive, the disadvantages and hazards accompanying, its use are discussed. Engineering techniques recognized as best modern practice are discussed in relation to the effect of simple air-injection development of properties on postwar operations and Probable ultimate recovery of oil. The report is an introduction to where, when, why, and how an air-injection project should be installed and operated; it is not intended to be an engineering manual for technical guidance in the selection, development, and operation of simulative methods of oil recovery.The report is intended mainly for these thousands of operators in the Appalachian region owning a few wells prodding small quantities or oil daily. Many such operators are anxious to increase their production rates by simulative means and to rehabilitate their wells so that they will produce more oil to help win the war but, in general, are unfamiliar with secondary-recovery operations and cannot afford to hire technical assistance."

Sep 1, 1944

By H. J. Rowley

THERE are many varieties of limestone, but for the general purposes of the pulp and paper industry, two classifications are sufficient: (1) High-calcium stone, which should be quite free from impurities and contain not less then 90 per cent calcium carbonate. (2) High-magnesium stone, containing not less than 25 per cent of magnesium carbonate. Before proceeding with detail on the use of limestone and lime in the industry, a few words regarding the pulp products made in Canada are desirable. By far the largest tonnage is made by grinding spruce and balsam logs on rotating sandstones or on artificial abrasive stones of the Norton or Carborundum types. This mechanical or groundwood pulp finds its largest use in the production of newsprint paper, of which it comprises about 80 per cent of the total fibrous substance employed-the remaining 20 per cent being unbleached sulphite pulp. No limestone or lime is directly employed in making groundwood pulp, as contrasted with the chemically prepared pulps, all of which require one or the other form of the base for their processing. Sulphite pulps comprise the next largest tonnage group. They are produced by boiling, under pressure and at elevated temperatures, spruce and balsam wood in chip form in solutions of bisulphites and sulphurous acid. The usual bisulphites employed are those of calcium and magnesium. Sodium, potassium, and ammonium bisulphites give progressively better pulps, but to date, in the absence of efficient recovery methods, cost has precluded their use.

Jan 1, 1939

By Sean Dessureault

The ubiquity of big data, internet of things (IoT), and smart devices is radically changing society; our personal lives are being tracked, digitally motivated through gamification, where information has become an addiction at all income levels, genders, and generations. These forces should not be held at bay in mining; rather, we should embrace and take advantage of this phenomenon to improve safety and productivity. It is time to rethink long-held conventions behind Fleet Management Systems, such as permanently mounted hardware, connecting through cables and Bblack boxes^, equipment centric rather than operator-centric, wireless requirements, minimal to no feedback to the operator, and high costs. We should also reconsider how we are collecting much of our safety, training, and preoperational forms on paper that then, must be entered into computer systems for compliance, and rarely if ever used in analytics, rather than entering the data directly into a digital device. Collecting safety and location data directly digitally also unlocks the information contained in safety forms and audits enabling new data mining and analytical approaches. Managing then gaining value from this new, greatly expanded mountain of largely unstructured data, requires the use of modern tools and approaches, such as gamification and big data, as well as skill sets, not traditionally available in mines. Furthermore, tablets can now provide a better user experience as well as new sensors when compared with traditional fleet management systems (Mining Magazine 2019, 2016, 2015), at a fraction of the cost, employing the extremely esthetic and engaging visuals derived from the video game industry. Real case studies of these applications of both technology and approach, such as gamification, show that these tracking technologies can bring high visibility and large amounts of data to even the smallest operations and the challenge of making use of the data can be facilitated through the application of gamification. As with our personal smart devices, these technologies are poised to deliver huge improvements in operator feedback, tracking, and performance management, at a much lower cost per unit.

By Evan J. Owen, Virginia T. McLemore

There are tens of thousands of inactive mine features in 274 mining districts in New Mexico (including coal, uranium, metals, and industrial minerals districts). However, many of these mines have not been inventoried or prioritized for reclamation. Many of these mines have existing mine wastes, generated during mineral production, which could have potential for critical minerals, especially since the actual mineral production was generally for precious and base metals and not critical minerals. The purpose of this project is to characterize and estimate the critical mineral endowment of mine wastes and “beta-test” USGS sampling procedures. This project is important to the state of New Mexico because critical mineral resources must be identified before land exchanges, withdrawals or other land use decisions are made by government officials. Future mining of mine wastes that potentially contain critical minerals will directly benefit the economy of New Mexico. Possible re-mining of mine wastes could clean up these sites and pay for reclamation. Furthermore, this project will include training of younger, professional geologists and students in economic and reclamation geology by the PIs.

Feb 1, 2024

By K. J. Liles

The U.S. Bureau of Mines evaluated the physical properties of ceramic particulate composites made from titanium nitride (TiN), alumina (AI203), and aluminum nitride (AlN) as part of a program to meet the high-performance demands on structural materials for new and emerging technologies. Samples containing from 20 to 80 wt pct TiN were pressed and fired, and their composition, Vickers hardness, modulus of rupture (MOR), and fracture toughness were determined. X-ray diffraction and scanning electron microscope (SEM) analyses showed that, depending on the amount of TiN added, the microstructure of the samples consisted of either a titanium-aluminum-oxynitride (TiAlON) particulate in a spinel matrix or a spinel particulate in a TiAlON matrix. The best results of the physical tests were achieved on a mixture of 40 wt pct TiN, 30 wt pct A1203, and 30 wt pct AIN. Sintering aids were added in 1-and 3-mol-pct increments to the 40-30-30 mixture to determine their effect on microstructure and physical properties. Results of an analysis of variancf' on a 4 by 4 factorial analysis showed significant effects on density, MOR, and Vickers hardness.

Jan 1, 1989

By Danqing Gao, Brijes Mishra

Spatial variance of rock properties is an important characteristic of rock which addresses the heterogeneity of mechanical and physical properties and their effect on underground mining. Assessing spatial variance can be useful for both locating potential difficult grounds and performing reliability analysis in the mining support system. This study shows a microscale numerical model for rock material based on continuum mechanics. To consider the spatial correlation factor of mechanical properties in realistic rock mass, this study introduces a spatial correlation concept into the traditional type III extreme value distribution model. Based on the improved microscale random model, we conducted a series of numerical uniaxial compressive tests and one longwall mine model to investigate the progressive failure of rock. The results show that spatial correlation factor can significantly affect the load-deformation curves and fracture patterns. The spatial variance model was applied to a longwall mine that included several cutting sequences to observe the influence of the spatial variance on roof behavior. The cohesion and friction random fields induced failure that propagated randomly through the immediate roof in different entries. The results showed that the spatial variance provides an accurate prediction of erratic roof falls in coal mines.

Jul 20, 2020