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By E. Özberk

Uranium minerals are often associated with iron minerals, and during the hydrometallurgical processing of the uranium ores, iron plays several significant roles. The presence of Fe(III) in solution promotes the oxidative acid leaching for the recovery of uranium. The control of the distribution of impurities in milling and refining is also affected by dissolved iron. When rejected from the process streams, iron usually collects other impurities and contributes to the stabilization of the wastes for final disposal. These roles of iron, as they relate to current uranium processing operations, are discussed in detail, and some broad and historical perspectives are also presented.

Jan 1, 2006

By William Seymour

"INTRODUCTION Byproduct-coke manufacture is one of our country's most essential in¬dustries; its importance was strikingly accentuated by the demands of World War II. This paper reviews recent progress in various phases of byproduct-coke operations for the production of metallurgical coke particularly that used as blast-furnace fuel.In the early days of the by-product-coke industry in the United States high-grade bituminous coking coals, both high-volatile or gas coal and low-volatile Pocahontas coal, were plentiful, and the selection and mixing of coals for coke-oven use were minor problems.The demands of World War I for the production of iron, steel, and coke aroused and stimulated new interest in the investigation of the reserves, characteristics, and properties of our coking coals. During that war the increased demand for coke reached a critical stage, and the shortage of high-grade coking coals necessitated the use of cols of inferior quality and of different coking characteristics than those previously used.The period of prosperity following World War I brought much progress and development in the by-product-coke industry. Methods of testing coal and coke were improved. The search for satisfactory coking coals was continued, and construction and design of byproduct ovens were improved."

Jun 1, 1946

By James E. Norman

[The flotation of mica is mentioned frequently in the literature, but must of the references have dealt with the recovery of mica by the old anionic collectors. The first use of the new cationic reagents indicated their superiority- as collectors in the flotation and a. agglomerate tabling of micas, feldspars, quartz, clay, and other acidic mineral, but the separation n of these minerals from each other necessitated study of the flotation of each mineral.]

Jan 1, 1941

By Ximing Yuan, Yongsheng Xu, Hongjie Li

A study of a static demolition agent that can be used underwater has been carried out. A new type of granulated static demolition agent with rapid reaction has been tested in several hundred experiments. It can be used conveniently and simply in the field. It demonstrates a fast reaction rate with high expansion pressures. The important characteristic of the new type of granulated static demolition agent is the ability to function underwater. It will destroy rock and the other brittle material without flyrock, vibration, shock wave, toxic gas or noise. The reaction rate can be controlled within 30-60 minutes. It is difficult to use these products when the reaction rate is less than 30 minutes and it is less efficient when the reaction rate is longer than 60 minutes. The reaction rate is slightly increased after the material is kept in storage for two years. A new type of the hydraulic device that is used to measure the expansion pressure of solid materials has been designed. The expansion pressure of the granulated static demolition agent has been tested with the device. It is shows that the expansion pressure of the granulated static demolition agent can get to 80~120MPa in 60 minutes. Also included is a discussion of the thermodynamics of the static demolition agent.

Jan 1, 2003

By H. Dong, J. J. Valencia, L. Nastac

"A comprehensive computer model was developed to understand and optimize the centrifugal casting process for manufacturing TiC/Al-bronze friction drums. Performance of these components requires proper distribution of TiC particles, which is shown by dimensional analysis to be dominated by centrifugal buoyancy effects and solidification kinetics.The model addresses the following: (1) a rheology-viscosity model of the interference between moving particles, (2) engulfment (entrapment) or pushing of particles in the mushy region by the advancing solid/liquid interface, (3) nucleation and growth of equiaxed and eutectic phases, (4) effects of particle size, particle concentration, and cooling rate on the final grain size, and (5) the impingement effect of particles on the nucleation and growth kinetics of solidifying microstructure.Parametric studies were conducted using the computer model to investigate the effects of various process and material parameters on the distribution of TiC particles. The effects of the volume fraction, size, and morphology of the particles (including clusters and agglomerates) on the particle distribution were evaluated in detail. The complex interaction between the solidifying structure and insoluble ceramic particles in centrifugally-cast metal-matrix-composites was also investigated.The model predictions of particle distribution and microstructure were validated with experimental data for centrifugally-cast A356/SiC and TiC/Al-bronze alloys.This work was conducted by the National Center for Excellence in Metalworking Technology, operated by Concurrent Technologies Corporation under contract No. N00140-92- C-BC49 to the U.S. Navy as part of the U.S. Navy Manufacturing Technology Program."

Jan 1, 2000

By Derek V. Ellis

Coastal and marine mines affect the seabed?s biological resources, eg fisheries, when large volume wastes such as tailings are placed on the seabed, and by the extraction processes from marine mining. Worldwide monitoring of such effects for the past 30+ years now provides information to describe Best Practice design, construction and monitoring procedures. The critical environmental factors for submarine tailings placement (STP) are the selection of an appropriate deposition site and discharge depth, the deposition rate of the tailings, and the speed of biodiversity recovery to a sustainable ecological succession. These should be predictable at new sites using current modeling and experimental procedures. Prediction procedures are still needed to minimize potential destabilization of deposited tailings, and consequent biodiversity recovery setbacks. Comparable environmental information is needed from marine mining sites.

May 1, 2002

By B. K. Shibler, A. O. Ipsen, W. W. Agey

"INTRODUCTION As a part of the program of investigation of domestic sources of manganese ore, mining engineers of the Bureau of Mines obtained and examined samples of ore from six properties in the vicinity of Pioche, Lincoln County, Nev., and from one property near Caliente, Lincoln County, Nev. As the ores were too low-grade to be acceptable for the direct production of ferromanganese, their amenability to concentration by ore-dressing methods was investigated.In general, the Pioche ores had a low manganese content and, owing to extremely intimate association of manganese minerals with iron oxide and nonmetallic gangue, were refractory to concentration by ore-dressing methods. Only two samples (Zero Gap and Wheeler ores) were amenable to the production of concentrates that would sinter to a marketable plus 35-percent manganese grade. The Prince Consolidated and Ely Valley No. 1.ores were roasted and sintered to produce lead-silver-zinc fumes. The residues were of possible value as manganiferous iron ore. No marketable manganese products were made from Calton semi-oxidized ore, but over 80 percent recoveries of lead, silver, and zinc were made by bulk sulfide flotation followed by Diming of the sulfide concentrate. No satisfactory results were obtained by treatment of Golden Eagle and Ely Valley No. 2 ores.The Cudverwell ore was amenable to the production of high-grade manganese concentrates by ore-drssing methods. However, fine grinding was required to effect mineral liberation, and loss of manganese as slime limited the mangenese recoveries obtainable.In the coarse of the investigations, many data were obtained and compiled, but for the sake of brevity, several data, of secondary importance have been omitted or condensed, and only the tests giving the more promising results are discussed in detail. For convenience, the report has been divided into two parts, one opertaining to the Pioche ores and the other summarzing results obtained by testing Culverwell ore."

Aug 1, 1947

By A. T. Iannacchione

The Bureau of Mines established geologic factors affecting the mining of the Lower Kittanning coalbed to aid in coalbed minability studies and examined the occurrence of "wants" (places where coal is missing) and types of unstable roof rock strata. Trends established from mapping, including prediction of areas of high methane emissions, were extrapolated to unmined areas. 'Wants' in the coalbed are of two types: Erosional and depositional. Erosional features occur where north-south-trending sand-filled channels cut into the coalbed. Variations in depositional environments have caused the coalbed to "split" into several thinner units. Slickensides, commonly indicative of unstable roof, are adjacent to and on the underside of sandstone channels; they were caused by differential compaction and by soft sediment sliding along the contact between the sandstone and adjacent shale. The frequency of unstable roof also increases where the interval between the Middle and Lower Kittanning coalbed is less than 30 feet. The zones of weakness at the contacts above and below the Middle Kittanning coalbed are the controlling factors for unstable roof in these strata. Methane emissions from the coalbed are controlled primarily by depth, fracture permeability, and rank of coal. Local geologic factors are coalbed thickness, associated rock strata, structure, and proximity to outcrop.

Jan 1, 1979

By Antoine F. Mulaba

Introduction Copper and cobalt oxide mineral deposits formed by the atmospheric weathering of near surface sulphide deposits are commonplace in the Democratic Republic of Congo. The most common route for the extraction of these metals is a hydrometallurgical one in which the base metal oxides are dissolved in sulphuric acid and then concentrated further by solvent extraction. However, as many of these deposits are relatively low grade (i.e. 0.5-1.8%Co and 2-4% Cu) and can also contain large amounts of acid consuming gangue minerals (i.e. dolomitic, micaeous, and/or siliceous), the hydrometallurgical route becomes uneconomic due to the excessive acid leaching costs. Some means of pre-concentration ahead of leaching is then desirable to improve the process economics. Apart from the small scale mining (Pan. Afr. News Agency, 2000) handpicking, although not easy, oxide concentration by flotation has been suggested. For the flotation process, the two most common approaches are controlled potential sulphidisation (CPS) and the fatty acid flotation method. The preferred method is dictated by the nature of the mineral makeup of the gangue. Being secondary deposits, the gangue associated with these ores is often complex and can play a significant role in the overall flotation efficiency. Laboratory flotation experience gained from the testing of a number of different ores of this type has revealed that it is not possible to prescribe a set method for the flotation of various ore types. Each ore needs to be analysed very carefully before and after laboratory flotation on an individual basis in order to arrive at an acceptable flotation technique Laboratory flotation testwork was carried out on three different samples from the DRC in attempts to isolate some of the more important variables affecting the flotation of copper and cobalt oxide minerals from these weathered deposits. This paper describes some early results achieved and experiences gained with these different ores ahead of a more detailed flotation test program which will follow in the near future on receipt of a significant quantity of a more representative sample. Controlled Potential Sulphidisation (CPS) was used in an attempt to achieve acceptable recoveries of both copper and cobalt.

Jan 1, 2005

By S Hapugoda, J R. Manuel, M P. Ma, L Lu

Iron ore sinter quality depends heavily on the mineralogy, textures and physical structure of the sinter, which is formed upon solidification of the primary sinter melt. The interactions of the initial sinter melt with its surrounding materials will impact on the properties of the primary sinter melt and consequently the solidified structure of the sinter. By using a high-temperature visualisation system, in situ studies have been conducted on the effects of melt compositions (Al2O3, SiO2 and MgO) on the interfacial phenomena of the sinter melt on a natural iron ore substrate. It was found that the melt composition significantly influenced the wettability between the sinter melt and the iron ore substrate. The interactions between the sinter melt and the natural iron ore substrate were also examined. Such interactions can lead to further changes of sinter melt composition and hence the sinter melt properties that, in turn, further affect the wetting behaviour of the sinter melt.CITATION:Ma, M P, Lu, L, Hapugoda, S and Manuel, J R, 2013. Effects of melt composition on the interactions of sinter melt on a natural iron ore substrate, in Proceedings Iron Ore 2013 , pp 431-440 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By E. J. Haas, K. A. Rost

"This study sought to identify changes in continuous mining machine (CMM) operators’ risk perception and risk behaviors as a result of adding a proximity detection system (PDS) into their environment. To accomplish this research task, 9 CMM operators from 5 locations were interviewed. Interviews were thematically analyzed for constructs including patterns in risk perception and behavior before and after PDS integration and the process of adapting to the PDS. Operators discussed standing in the red zone less than they did before using the PDS; however, they also discussed other risky decisions they made while learning how to operate their CMM with the PDS technology such as “cheating” the technology and working faster to meet production goals. The process of relearning job tasks with technology and unintended behaviors as a result of that relearning process need to be taken into account when introducing new technology into the mine environment. The study results show an in-depth view of mine workers’ perspectives and how their job tasks and environment could be or are affected when learning how to use new technology that are relevant to companies and mine operators when introducing new technology into the mine environment. INTRODUCTION Established “red zones” can help prevent striking and pinning incidents by providing guidance to continuous mining machine (CMM) operators about where they should stand and not stand while operating a CMM. Although red zones influence operator placement positions, these guidelines are not foolproof safety mechanisms. Depending on the job task and circumstances of the mine environment, a CMM operator may unintentionally or intentionally stand in a red zone. For example, CMM operators may work in close proximity to their CMM for better visual attention cues and the ability to work at a higher rate of production [1-3]. To further enhance protection and prevent collisions between vehicles and mine workers, a proximity detection system (PDS) was developed for the industry. The PDS determines an individual’s position relative to a specific piece of machinery, issues visual and/or audible warnings to the mine worker to change positions, and, if necessary, disables machine motion [4]. The introduction of new technology within other sectors has been identified as a factor that influences work decisions. Specifically, previous research demonstrates that when technology debuts there can be an initial intrinsic risk perceived among users about how the technology will interact with their current environment and behaviors; however, these ambiguities, including the possible risks and benefits, are seldom studied [5]. Some research suggests that the constant presence of technology can disrupt situation awareness and decision-making capabilities by increasing worker responsibilities and worker cognitive demands [6-8]. Further, if workers’ perceived risks both with and without technology are misjudged, unsafe decisions that result in human error and injury may be more likely [9-11]. Although these statements are provided within a broad contextual framework, they support the need to study how technology is perceived among end users in their own environment. Because research about technological impact on worker behaviors has suggested both positive and negative consequences of technology, this issue is worth addressing in the mining industry. Specifically, research has not determined whether CMM operators view their placement choices in the red zone as safe or risky and what effect PDS technology has, if any, on risk perception and subsequent risk behavior."

Jan 1, 2015

By Nelson Rivera

El presente texto analiza la crisis económica y su relación con el Banco Minero. Para ello, se revisa las dos últimas recesiones económicas que tuvo el Banco entre 1975 y 1982, donde la crisis se agudizó por una caída en los precios de los metales y una inflación de costos que no pudo ser transmitida al precio de venta. Como consecuencia de ello, las empresas mineras que tuvieron préstamos, acusaron pérdidas en sus ejercicios e incumplieron en el pago de sus obligaciones. Como medida anti-crisis, el Banco Minero estableció comisiones de alto nivel para evaluar las situaciones y recomendar la dación de dispositivos legales que permitieron asistir a los Pequeños y Medianos mineros en la restitución de liquidez mediante préstamos sobre liquidaciones a precios deprimidos, Asimismo, generó la consolidación, refinanciación y moratoria de los clientes que estaban en suspensión de pagos de las obligaciones contraídas con el Banco Minero y la creación de líneas de crédito especiales para la Pequeña Minería.

Mar 1, 1985

By James E. Norman

[The flotation of mica is mentioned frequently in the literature, but most of the references have dealt with the recovery of mica by the old anionic collectors. The first use of the new cationic reagents indicated their superiority as collectors in the flotation and agglomerate tabling of micas, feldspars, guartz, clay, and other acidic minerals, but the separation of these minerals from each other necessitated of the study of the flotation of each mineral.]

Jan 1, 1941

By Thomas A. Gwynn

When Lewis and Clark first pushed their boats up the Missouri River, Meriwether Lewis reported the presence of coal in the western states by saying in 1802 that it "burnt tolerably well and afforded but little flame or smoke but produced a hot and lasting fire". Lewis would have been amazed and bewildered at the history of coal development in this region and the more recent political-socio-economic-environmental confrontations of today. Certainly without this coal the railroads would not have readily pushed into our western states, and the progress of this region would have suffered. The coal industry has passed from a period when "coal was king" to a period of depression in the industry, but its importance is being revived. A contributing and simultaneous environmental concern has emerged in the nation and in many states during the past ten years, partly caused by newly imposed standards for sulfur content of fuels. Much of the midwest and eastern coal cannot be used because of high sulfur content, shifting attention to the low sulfur coal deposits of the western states. In the western states, lands disturbed by strip mining or even underlain by strippable coal are small compared to the total acreage, and usually mining operations are on lands not under cultivation. There are some farm lands being disturbed by surface mining, but this is often over-emphasized. In states like New Mexico and Arizona the percentage is less. The value of the minerals underlying the surface certainly must be considered along with the value of the surface, and sometimes proper reclamation following mining can result in higher ultimate usage of the land.

Jan 1, 1974

By Lloyd A. Morley

Two mine electrical power system simulations are presented. The first is a batch processed procedure capable of modeling a single mining machine consisting of a number of motors operating under various loads. These loads are the mechanical torque loads present at the motor shaft. The second simulation is a more flexible tool for modeling entire mine electrical power systems~ Detailed analyses of bus voltages, transmission-line power flows, and machine behavior are possible. This simulation operates interactively and the power system is configured as the user responds to program generated questions and requests. Development of the theory behind the programming, as well as detailed explanations of the models, is presented. Examples are provided to demonstrate simulation capabilities.

Jan 1, 1978

By D. Van Tonder, C. Edwards

ABSTRACT Solvent extraction is used in many acid leach uranium circuits to upgrade and purify the uranium-bearing solution prior to final product precipitation. A number of strip options are available to recover the uranium from the loaded organic. This paper compares seven of these options on the basis of typical capital and operating costs for the solvent extraction circuit and downstream uranium processing and also considers other related issues. The aim is to provide an objective comparative assessment of these options that could be used as a qualitative guide in process selection or improvement.

Jan 1, 2013

By Henry G. Granger

I. INTRODUCTION. REPEATED failures in attempts to work gold-bearing gravels by means of suction-dredges have created the impression that this method is impracticable. The suction-dredges have failed from three special causes excessive wear and frequent breakage of pump-shell, runners and liners; inability to dredge compact gravel which would ,not. readily move towards the intake; and, most important of all, closing. of the suction-pipe by stones too large to enter it. In my opinion, all three causes of trouble may be remedied: the first, by making stronger the parts most liable to wear and breakage; the second, by means for loosening the gravel at the intake; and the third, by sufficiently... Increasing.. the diameter of the suction-pipe. In suction gold-dredges, this diameter has not usually exceeded 10 or 12 in.; whereas there are few profitable gold-fields which can bee considered dredgeable, in which stones more than' 12 in. in diameter, are-.not frequently encountered. II. AN EFFECTIVE SUCTION-DREDGE. In harbor-operations, much larger stones are handled by suction-dredges.., The large dredge of the Henry Steers Contracting Co. worked for nearly four years at League Island, Philadelphia, where it sucked up, passed through the pump, and forced through 3,700 ft. of discharge-pipe; gravel containing boulders up to 200 lb. in weight. This was done with no bad breaks and few shut-downs. The cutter; and liners were the only parts liable to damage, and these were easily replaced with brief interruption of work. The chrome-steel liners are said to have lasted from six to nine months. I am informed that this dredge worked continously for nine

Apr 1, 1909

By Dushasan Kundu, B. N. Shivakiran Bhaktha, Khanindra Pathak, Sarbojit Mukherjee

Mine safety and quality of life of miner working in underground mines depend to a large extent on mine illumination and communication. The provisioning of reliable, safe, and cost-effective illumination is critical, particularly in underground gassy coal mines. To prevent firedamp explosion by electrical switching operation in coal mining industry requires implementing intrinsically safe illumination circuit. The luminaire design also needs to be certified and installed properly. The current illumination systems installed inside mines require a lot of energy which is obtained from nonrenewable resources. In this work, the design and implementation of solar-powered optical fiber-based illumination are studied and implemented in the Jhanjra underground coal mine, Eastern Coalfield Limited, and a Li-Fi-based communication system for underground coal mines is proposed. Silicate optical fibers of various core diameters and numerical apertures are characterized for illumination applications and their efficiencies are reported. The possibility of achieving optical fiber-based solar, laser, and hybrid illuminations in underground mines is discussed. The design and fabrication of a Fresnel lens-based solar tracker for solar illumination are also presented. The optical fiber-based illumination system is installed in an underground coal mine and the illumination of over 70 lux is achieved at the work plane. Finally, optical fiber-based illumination and simultaneous basic Li-Fi communication are demonstrated and will be beneficial to the underground coal mining industry.

Apr 14, 2023

By E. P. Youngman

This paper is one of a series of digests of foreign mining legislation and court decisions that is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the mining laws of British Honduras has been prepared from the best available information in Washington and is released subject to amplification or correction, if necessary, by United States foreign-service officers. INTRODUCTION The mining law governing all mineral substances other than oil is ordinance No. 7 of 1927 (Minerals Ordinance, 1927), passed by the Legislative Council on March 25, 1927. The accompanying regulations, No. 3 of 1932 (General Minerals Regulations, 1932), made under the authority of section 66 of the minerals ordinance, were made by the Governor in Council on December 23, 1931.

Jan 1, 1934

By Wang Shulan

The synthesis process of BaTiO3 from TiO2 and BaCO3 in the molten NaOH-KOH at 350oC was studied by the A.C impedance technique. The A.C. impedance of molten NaOH-KOH (xNaOH = 0.36) and the variation of the conductivity of the salt with time during the synthesized process were measured. The synthesized reaction of the BaTiO3 and the decomposition reaction of BaCO3 are fast and were finished in 10min. The interaction between TiO2, BaO and BaTiO3 and the molten salt was confirmed by the variation of the conductivity.

Jan 1, 2005