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By Arno C. Fieldner

Six years ago, I addressed the annual meeting of the American Society for Testing Materials on "Fuels of Today and Tomorrow."3/ Since then, our country has been drawn into another great war of veritably global extent, with unprecedented demands on fuels, foods, and materials in general. My purpose in this address is to review the changes in fuel supply and demand since 1937 and to give you my views on the outlook for the future. CONDITIONS IN. 1237 Daring 1936 the United States produced and consumed one-third of the world production of coal, two-thirds of the petroleum, and about 95 percent of the natural gas. Two-thirds of the oil produced in all countries since the discovery well was drilled in 1859 had come from American wells. With the exception of the three depression years 1931, 1932, and 1933, new oil reserves were being discovered since 1924 well in excess of our increasing rate of consumption. Discoveries of natural gas, likewise, were tremendous in volume, and this fuel was being transported to most parts of the country by pipe lines; some of them more than 1,000 miles long. We had all kinds of mineral fuels in abundance and at prices that did not stint anyone in the maximum utilization of the mechanical devices that were being developed on every hand. No one suspected that the time might come in a few years when, gasoline would be doled out to some of us at the rate of 1-1/2 gallons a week or that many of our fuel-oil furnaces would have to be converted to burn coal. Of course, these restrictions are due to unusual war conditions, such as lack of coastwise tanker transportation, unprecedented demand for aviation gasoline, and the shortage of rubber for automotive tires. However, these shortages do call our attention to the vital part of petroleum reserves in our country's future position among nations. Therefore, it is of special interest to review briefly the relations of recent supply and demand with respect to our various mineral fuels.

Jan 1, 1943

By W. P. Stroud

In this U.S. Bureau of Mines report, the conditions required for the direct reconstruction of a tomogram from observed line integrals are examined. Because of the limited access to the working faces in coal mines, the special case of access to only two opposite faces is emphasized. Classical matrix methods were used for small dimensional (2 by 2, 3 by 3, and 4 by 4) applications to determine the limitations and the requirements for a solution. The results for large (n by n) grids were then inferred and generalized from those of the smaller grids and matrices. Limited access tomography is found to be appropriate for in-seam hazard detection from seismic and microwave data, but it is shown that additional data must be added to obtain a direct solution.

Jan 1, 2010

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

By K G. Fleetwood

This paper proposes an approach to determine the influence of non-ideal detonation characteristics related to the charge diameter, explosive type and confinement conditions on the available shock energy of ANFO and a representative chemically-sensitised (gassed) emulsion. The proposed degrees of non-ideality of the two different blasting agents are indicated by the Gurney ratios, determined from existing cylinder expansion testing data. The influence of the non-ideal detonation properties on blast design and performance are also compared using a series of theoretical, equal powder factor open pit blasting patterns with hole diameters ranging from 102 mm to 270 mm. The non-ideal shock energy factor (NSEF), which is the available shock energy per tonne of blasted material (MJ/t), is used to compare the different blasting patterns as charged with either ANFO or the gassed emulsion of equal charge density (0.85 g/cm3). The intended purpose of this investigation is to provide explosive users with an approach to compare different explosive types or charge diameters in the absence of dedicated non-ideal detonation modelling, which is generally not available to explosives users.The results of the comparisons suggest that at low charge densities, the example gassed emulsion displays a higher velocity of detonation (VOD) than ANFO in smaller charge diameters but similar degrees of non-ideality (based on proposed Gurney ratios). The results also suggest that the confined, non-ideal gassed emulsion VOD at hole diameters greater than 270 mm can be less than ANFO due to the low density effects on the emulsion matrix. The differences in non-ideal detonation properties and Gurney ratios between the ANFO and gassed emulsion resulted in gassed emulsion NSEF values ranging from 15 per cent lower to 65 per cent higher than ANFO for equal powder-factor patterns in blasthole diameters from 102 mm to 270 mm.

Nov 8, 2011

By V O’Brien

The suitability of magnetic surveys flown at low altitudes to identify buried heavy mineral (HM) strands has long been accepted. This is despite the low intensity magnetic response often obtained from such strands. The fundamentals of the magnetic survey method dictate that the closer the instrument is to the source the stronger the response. As such the optimal elevation for the magnetometer is at or near the surface. Iluka sought to use a ground based magnetometer to aid in the exploration target generation process and allow accurate targeting of exploration drill holes. Following the initial trial Iluka recognised the potential additional application of data obtained by a ground based magnetometer over known strand deposits. The detail of the ground magnetic images can confirm the assumed strand continuity between cross-sections of close spaced drilling and can aid in the definition of the geometry of different generations of mineralisation. The ability to confidently determine that the deposit has not been truncated by post emplacement erosion of the mineralised deposit may enable reductions in drilling requirements as well as assisting mine planning activities. Iluka intends to investigate advanced modelling of the magnetic data to determine the level of strand geometry and HM content resolution that can be achieved from the ground magnetic survey data and its potential application in the mining grade control process.It is anticipated that the surveying of Iluka’s known resource deposits will provide the ability to correlate the magnetic response from new exploration targets with those from known deposits for a given depth, HM grade and mineralogy suite.

Oct 5, 2011

By R. W. Geehan

The Bureau of Mines has been investigating deposits of critical and essential minerals in the United States since 1939. Bureau engineers made a preliminary examination of the Morefield mine early in 1943 and recommended investigation by trenching and diamond drilling, The Bureau of Mines conducted work from August to December of 1943, which indicated that the Morefield mine was a favorable location for an experimental mining program. The Bureau of Mines carried on such a program from September 1947 to March 1949. The property investigated is 30 miles southwest of Richmond in Amelia County, Va. (fig. 1). During World War II mica and beryl were shipped from the Morefield mine, but after the high prices and premiums paid during the war years were not available the mine was closed.

Jan 1, 1953

By C. Hudson, D. Tremblay, A. Frey

"A discussion of the design, challenges and successes associated with the commissioning of the gravity recovery circuit at Canada’s newest open pit gold mine - Atlantic Gold’s Moose River Consolidated Project in Nova Scotia, Canada is presented. An overview of the project, its historical significance and overall flowsheet is provided with special focus given to the design and selection of the gravity circuit equipment including the scalping screen, gravity concentrators and the novel intensive leaching technology selected for the project. The performance of the gravity circuit is benchmarked against the feasibility study process design specifications and the outcomes are discussed. Challenges encountered during commissioning are also presented, including the use of third-party automation and the effects of screen sizing on overall gravity circuit performance. Mechanical modifications made to the Sepro Leach Reactor for the Moose River project are also discussed. A detailed technical review of the mechanical and operational aspects of the Sepro Leach Reactor is provided with key operational data on leach times, recoveries, reagent usage, solid-liquid separation, pregnant solution quality and its influence on bullion purity.INTRODUCTION Atlantic Gold Corporation’s Moose River Touquoy Mill in Nova Scotia, Canada was commissioned in the fourth quarter of 2017 with commercial production declared in March of 2018. The 2 Mtpa process plant uses a conventional, gravity-CIL process. This site was previously mined in the 1870s. Interest waned in the early 1900s but resumed in the 1930s and the mine was brought back into production in 1935 until an underground mine collapse in 1936. This mining district became famous after CRBC radio commenced a ground breaking, around the clock, broadcast of the rescue operations. Over 100 million people listened to the broadcast from Canada, the United States and the United Kingdom. These broadcasts changed radio, transforming it from a medium for music to on the spot, breaking news reporting. The mill was constructed by Ausenco on a fixed price EPC contract in the historic Moose River gold mining district, 95 km north-east of Halifax by road. The mill will process ore from the adjacent Touquoy pit for the first 5+ years of operation; after the Touquoy reserves are exhausted, the mill will process ore trucked 37 km from the Beaver Dam deposit for an additional 5 years."

Jan 1, 2019

By J Rola

This paper outlines a laboratory-based design method, founded in critical state soil mechanics, for identification of an appropriate compaction specification to ensure dilative conditions prevail across the design TSF stress range. The method makes use of the critical state line (CSL) and consolidation tests prepared at varying compactive efforts. The CSL and consolidation curves are plotted together in e-log p’ space, with the compaction curves transformed from vertical effective stress to mean effective stress using the coefficient of earth pressure at rest (K0). Consideration is given to the sensitivity of K0 as it is generally not available during the design phase. An example of the design method is illustrated with laboratory data.

Jul 1, 2021

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

The Pilbara region, located in the north-west of Western Australia, is significant as the second-largest source of iron ore on the planet. Iron ore mines owned and operated by Pilbara Iron are located within the Hamersley Basin. This paper refers to the Greater Paraburdoo mines, the 4WEST and 4EAST pits, located on the southern margin of the Hamersley Basin. The groundwater model refers to ephemeral watercourses: Seven Mile and Pirraburdoo creeks, which are adjacent to the two pits, and Ratty Springs, located upstream from 4WEST and within Pirraburdoo creek. The spring and creeks hold cultural heritage significance for local Aboriginal communities. Two of these, the Gobawarrah Minduarra Yinhawanga (GMY) and Innawonga native title claim groups, initiated hydrological work on the two creeks and Ratty Springs, with the aim of determining the affects of dewatering on the natural water flows of these systems. The numerical model used to simulate drawdown in the Pirraburdoo and Seven Mile Creeks was derived from PMWIN Pro software and covered an area of 77 km2. The modelling period was from January 1998 to December 2004, and the prediction period was from January 2005 to December 2015. The model has four layers and incorporated effects caused by mining voids, 4WEST and 4EAST pits, creek bed material, weathered bedrock below creeks and surrounding banded iron formations (BIF). The model has been calibrated using the trial-and-error method set down by Middelmis et al (2001). The current dewatering schedule (12 ML/day) in the 4WEST and 4EAST mining areas does not affect the water table levels in the adjacent creeks significantly or for any considerable periods of time. However, changes to mine plans may occur, for example, in response to changed commodity price and may lead to significant increase in rates of vertical advancement. This, in turn, affects dewatering schedules, as greater vertical advancement requires increased dewatering effort. When an accelerated mine plan is applied to the model and dewatering rates increased to 18 ML/day, drawdowns in the creeks are more noticeable. The model has therefore helped to indicate the extent to which increased dewatering rates may be acceptable, especially in terms of immediate and longer-term damage to riparian species, ie Melaleuca and Eucalypt. Predictions from the model may also allow mine planners to schedule decreased rates of vertical advancement, where these are required to meet environmental constraints.

Jan 1, 2006

By Minghui Li

China is the largest coal producer in the world. In 2012, the coal production in China is 3.65billion tonnes, accounting for approximately 49% of global coal production. The raw coal production in 2012 was 3.8% more than the year 2011. 56% of total raw coal has been washed. The increase in raw coal production also promotes technology to be developed and brings separation capacity become larger and larger in coal processing in China. At present, over 40 extra-large scale coal preparation plants (each plant has capacity of more than 10 Mtpa) are in operation in China, the largest one is 32.5 Mtpa. Heavy medium separation are widely used in new built coal preparation, the washing limit for thermal coal feed lower and lower, the equipment selection tends larger which brings the whole washing system simplified, the local equipment developed and manufactured are more and more used. By discussing designs of several typical thermal coal preparation plants and coking coal preparation plants in China, this thesis introduces the current design of China?s extra-large coal preparation plants, and sums up the prevailing design features and trends of extra-large coal preparation plants.

Aug 1, 2013

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

As land resources decrease, commodity prices increase, and technology evolves, deep sea mining is becoming a viable alternative to meet the increasing demand for minerals. Successful deep sea mining operations are built on sound identification of the resource, proper selection of equipment, a thoughtful production plan, and good project management. These four key activities can be further optimized by analyzing how the spatial variability and uncertainty of the ore body properties impact the final mining operation. To address this problem, IHC Merwede is in the process of developing a risk quantification framework in the context of deep sea mining, which makes use of state of the art geostatistical simulation methods and transfer functions to quantify geological uncertainty and translate it into decision or project risk. The paper introduces the Local Average Subdivision method (LAS) for generating simulated models of the deposit and presents a new extension to incorporate point measurements of geotechnical or ore grade properties. Due to its computational efficiency, the presented method is suitable for simulating largely extended sea floor deposits. The second part of the paper illustrates, through example case studies, the significant benefits of a risk based approach which translates geological uncertainty into financial or operational performance indicators. In particular, the focus is on assessing financial project risk and on the design optimization of the deep sea excavation equipment by analyzing cutting forces, specific energies, and power requirements.

Aug 1, 2013

By E Bouchard March, F Lavoie, B Legare, K Bourassa

Quebec Iron Ore (QIO), a subsidiary of Champion Iron Limited (Champion), completed the restart of the Bloom Lake iron ore mine located in the heart of the Labrador Trough region of Northern Quebec, Canada in February 2018. Prior to its restart, the concentrator flow sheet underwent major upgrades which brought the iron recovery to the highest of all Labrador Trough operations. After two profitable years of production, QIO, supported by Soutex, started to look at technologies to improve its current performance and integrate into its expansion project flow sheet. From the lessons learned while optimising Phase 1, the addition of a scavenger-cleaner processing stage was identified as an improvement opportunity to increase recovery, produce a higher-grade product, and further improve the stability of concentrate quality. In 2019, the NI-43101 feasibility study for the Phase 2 expansion, aiming to double the production of high-grade iron ore concentrate, was published. Based on the metallurgical test work, the hydraulic classifier was selected to perform the scavenger-cleaning duty for its well-established performance and known behaviour at the cleaning step in the Phase 1 plant. To validate laboratory results, a pilot scavenger-cleaning hydraulic classifier was installed in Phase 1. Although the hydraulic classifier was selected for the feasibility study, metallurgical test work performed with the REFLUX® classifier showed interesting potential. It was thus decided to also install a pilot RC300 Reflux classifier at the scavenger-cleaning stage in Phase 1. Despite their apparent great similarities, the metallurgical performance was significantly different, and many dozens of sampling campaigns highlighted the different performance of both pieces of equipment considering the feed material particle size. This article presents the pilot plant results in terms of recovery, selectivity and stability for both the Reflux classifier and the hydraulic classifier operated in a scavenger-cleaner stage at the Bloom Lake iron ore concentrator.

Nov 8, 2021

By R. A. Beall

Consumable-electrode arc melting is now accepted throughout the industry as the best method for producing ingots of zirconium, titanium, molybdenum, and their alloys. In addition, the technique is widely used in laboratories for fusing samples of such metals as hafnium, chromium, tantalum, columbium, and thorium. The production of consumable electrodes from these metals presents some rather difficult problems, the accepted industrial solution being the use of heavy powder-metallurgy-type presses. This paper summarizes information on fabrication of consumable electrodes by this and alternative means, such as sintering, nippling, and welding lightly pressed compacts of scrap metal. A possible saving of considerable capital investment is shown in the case of sintered compacts. The electrical circuit components of a pilot sintering unit are analyzed. INTRODUCTION The consumable-electrode arc-melting process has been accepted by most of the industry as the best method at present for producing high-quality pure or alloy in-got from sponge titanium or zirconium. This technique is not particularly new, having been patented by Von Bolton (l)3/ in 1909 for melting tantalum. However, it has been applied to industrial-scale operation only in the last few years. Among the important contributions to this technique are the work of Kroll (2) and Parke and Ham (3) and the work reported by the Office of Naval Research (4). The Bureau of Mines-has added considerably to the knowledge of this process (5-9).

Jan 1, 1956

By Yang Jian-guang, Deng Zi-xiang, Zhang Xu-liang, Li Jun-yuan

"Hyperaccumulator biomass harvested after heavy-metal phytoremediation must be considered as hazardous waste that should be contained or treated appropriately before disposal or reuse. As a potential method to detoxify the biomass and to convert this material to a suitable bio-energy resource, the hydrothermal upgrading process was applied to remove heavy metals and upgrading crude bio-oil from Pteris vittata stems and leaves harvest. Parameters such as material granularity, temperature, Liquid/Solid (L/S, ml/g), pressure, duration and catalysts were examined for their effect on the removal efficiency of heavy metals and upgrading efficiency of crude bio-oil. Maximum heavy metal removal efficiency of>99% and crude bio-oil upgrading efficiency of 83% were attained with an 200 mesh (75 µm) granularity, LIS 40:1and23 MPa at 380°C in the presence ofO.l mol L-1 K2C03 for 30 min. GC-MS analysis results show that the resulting bio-oil mainly consists of benzene 11 %, ketone 42%, alcohols 14%, alkene 15% and ester 11 %, etc., and the relative molecular weight distribution lies in 94-282, carbon number distribution lies in 6-18, calorific value is 32MJkg-1.IntroductionPhytoremediation of soil or water with hyperaccumulator has been extensively explored in recent years [1-4]. Living plants can clean up soils or waterways. This approach exploits the ability of various plant species to thrive in high metal environments where large amounts of toxic elements are accumulated, such as heavy metals, and is particularly appropriate when slow remediation of relatively low metal concentrations is acceptable. Advantages compared with existing remediation methods include the minimal site destruction and destabilization, low environmental impact, and favourable aesthetics; advantages compared with biosorption include continuous in situ regeneration of the biomass, and the ability of living plant cells to supplement passive sorption of metals with metabolic mechanisms of metal uptake and detoxification [5-8]."

Jan 1, 2014

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 James P. Bennett

To improve construction materials for emerging chemical and metallurgical technologies, the Bureau of Mines is investigating the acid resistance of ceramic materials. In the study described here, eight commercial ceramic materials comprising two red shale, two fire clay, a silica, a silicon carbide, a carbon, and a high-alumina brick were evaluated. Samples were exposed to 20 wt-pct HC1 at 50° C for 110 days. The test apparatus designed to evaluate the materials is described. Changes in chemical and mineralogical composition, cold crushing strength, volume, and weight, and leach rates of AI, Ca, Fe, K, Mg, Na, Si, and Ti ions were monitored. In general, the statistically significant physical property changes that occurred were small. In many cases, no changes were detected.

Jan 1, 1982

Consumption and intensity of use trends for twelve metals, by industrial end use, were estimated for 1972 through 198Z. The trends were then forecast through 1993 using standard statistical methods. The intensity of use measure selected is the quantity of metal consumed per constant dollar output of a specific industrial sector. The metals studied were aluminum, chromium, cobalt, copper, lead, manganese, nickel, the platinum-group metals, tin, titanium, tungsten, and zinc. Average annual growth rates for the following four of the twelve metal increased from 1972-82 as follows: aluminum, 1.00 percent; platinum-group metals (consisting of platinum, palladium, and iridium), 8.83 percent; titanium, 7.82 percent; and tungsten, 6.09 percent. Consumption. for the remaining eight metals decreased at average annual rates ranging from 0.58 percent (copper) to 5.37 percent (manganese).

Jan 1, 1986