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By H. L. Riley

At the Southern Experiment Station, Tuscaloosa, Ala., reports are prepared from time to time on results of washability studies of coal from important beds in the Southern Appalachian region. The investigations that provide the material for these reports are made by the Bureau of Mines, United States Department of the Interior, in cooperation with the University of Alabama and the mine operators. The principal objective of a washability study is to obtain technically and commercially important data to aid in determining the best methods for preparing and utilizing the Nation's reserves, particularly of coking coals. Such information is also important from the standpoint of conservation, because it facilitates the selection of preparation methods that will yield an acceptable product with a minimum loss of coal to the rejects.

Jan 1, 1958

By Rudineli Demarque

Este artigo apresenta um estudo das características metalúrgicas, geométricas e microestruturais da soldagem TIG autógena aplicada em chapas de um aço AISI 304, o processo autógeno tipo cordão sobre chapa foi utilizado com a finalidade avaliar o comportamento deste aço quando submetido a ciclos térmicos distintos. A soldagem foi automatizada, na posição plana, e realizada com controle de velocidade com a finalidade de regular a energia adicionada ao material soldado. As variáveis de entrada foram a velocidade da tocha de soldagem TIG, e a corrente setada na máquina de solda. Foram avaliados os efeitos da variação da energia de soldagem sobre as características metalúrgicas do processo, sobre as características geométricas (penetração e largura) do cordão se solda, microestrutura, espaçamento dendrítico e microdureza da seção transversal da junta soldada. Os resultados indicaram uma forte influência sobre a geometria da junta soldadas, aumento de 28,5% na largura, 59,6% na profundidade e 44,6% na área, além de alterações microestruturais, aumento de 100% na quantidade de ferrita d, 12% na microdureza e 51,69% no espaçamento das dendritas no metal de solda, Além disso observaram-se ausência de defeitos nos passes isolados sobre as chapas.

Oct 30, 2017

By Dimas de Andrade Pacheco

O estudo do efeito da adição de nióbio em um ferro fundido branco alto cromo tratado termicamente com 25%Cr e 3%C foi estudado neste trabalho por microscopia ótica, microscopia eletrônica de varredura e difração de raios X. Partindo de uma liga hipereutética, a adição de 2% de nióbio foi definida considerando que todo Nb adicionado se encontraria na forma de carbonetos de nióbio, NbC, e com o objetivo de obter uma microestrutura próxima à eutética. A adição promoveu um refinamento da microestrutura, sendo que uma fração volumétrica de 27% de carbonetos M7C3 foi observada. Carbonetos grosseiros, inicialmente formados, não são facilmente observados. Uma microestrutura formada por NbC e eutético, M7C3 + matriz (austenita ou martensita), foi obtida. Os carbonetos de nióbio formados são encontrados principalmente na forma compacta. É esperado, portanto, que, a liga com adição de 2% de nióbio apresente melhor resistência ao desgaste abrasivo que a liga sem nióbio, em razão dos carbonetos primários, frágeis e grosseiros, terem sido praticamente suprimidos após a adição de Nb e uma microestrutura mais refinada tenha sido obtida.

Oct 30, 2017

By J. E. Nesset

"Significant progress has been made over the past few years on characterizing and understanding the hydrodynamic properties of frothers and collectors and their effect on flotation performance. This new understanding of the relationship between chemistry and hydrodynamics has dramatic implications for how flotation circuits should be controlled and optimized. Previous work has shown that choosing a frother of the right ‘strength’ is critical to the optimization process, and the work and discussion presented here serve to strengthen the argument. In addition, we know that collector chemistry will also influence hydrodynamic properties and needs to be taken into consideration. To achieve the desired outcome, the overall system of reagents and operating parameters must be considered. This paper describes and discusses some of the findings from recent research on frother and collector chemistry effects (on hydrodynamics), and how this knowledge can be used to improve flotation performance. Examples from plant experience are discussed.INTRODUCTIONFrothers perform various functions in flotation but the primary ones are control of bubble size in the pulp zone and stabilization of the froth zone. Laskowski (2003) was among the first to try to capture both roles in characterizing frothers in order to provide a basis for frother selection for a given duty, as well as to explore the link between function and frother chemistry (structure). The method he used requires bubble size data and a frothing index; the procedure has been simplified by Cappuccitti and Finch (2008) using gas hold-up to substitute for bubble size, and froth height (without overflow) as the froth stability metric. The gas hold-up/froth height relationship will be referred to as ‘hydrodynamic characterization’. Essentially, the gas hold-up parameter reflects the sum of the hydrodynamic conditions in the pulp phase (water in this case), i.e. the effect of bubble size plus the apparent impact of the water surrounding the bubble due to the frother (Finch, Nesset and Acuna, 2008). Similarly, the stable froth height parameter reflects the sum of hydrodynamic conditions in the froth, i.e. the effect of bubble size undergoing coalescence plus the influence of the water in the lamellae and Plateau borders between bubbles. It could be argued that the gas hold-up/froth height relationship is a superior one to simple bubble size/froth index for discerning differences in frother behaviour"

Jan 1, 2010

By Eric R. Bauer

The U.S. Bureau of Mines, in cooperation with a southwestern Pennsylvania coal mining company, BethEnergy Inc., Mine No. 60, Eighty-Four, PA, recently assessed the feasibility of using pre driven recovery rooms (open entry recovery) when longwall mining to increase the productivity of the coal extraction process. Two recovery entries, one 200 ft long and another 600 ft long, were supplementally supported with bolts, channels, and wire mesh, and either fly ash-cement piers or fiber cribs, then mined into by the longwall face. The recovery entries showed little deterioration as the supports provided adequate resistance to the front abutment loading. Compared with conventional recovery methods, the fullface recovery room allowed for panel extraction to be completed nearly 17 days faster and to reduce face equipment move time by 1-1/2 days. The potential productivity increase accompanying recovery rooms is greater than the cost of supporting a fullface recovery room. The fullface recovery room provided over 18 additional production days and the opportunity to mine nearly 68,400 st of coal per year per panel mined.

Jan 1, 1989

By W. M. Middleton

The exploiting of geothermal steam is a new endeavor in this country and is for that matter a very new science in the world. With the majority of steam wells in the world having been drilled during the last twelve years relatively little experience and knowledge has been gained that can guide us as compared to the techniques the oil and gas producers have developed for their use. We few technical personnel associated with the field find it a continuous challenge to understand and explain what effects or causes the various unusual phenomenon experienced. We have had unending discussions attempting to formulate pet theories which we can use as guides. We know, so the geologists tell us, that the source of the heat is from the hot magmatic core of the earth. Theory has it that the magma is cooling off and that hot gases are given off as this magma cools and shrinks. In volcanic' areas along fault lines where the magma reaches closer to the surface than in other areas, there is a higher concentration of gas evolution; consequently, geyser or geothermal areas are developed. As these hot gases rise toward the surface they encounter various minerals, including overlying bodies of water. It is into these underground lakes that our wells are penetrating. As the heat enters these lakes it spreads out by conduction, convection and water migration. We can strike this hot water over quite large areas in many of the geothermal fields. At present there is one anomaly to this in the United States as there is in Italy where our wells do not penetrate a hot water lake. This is at The Big Geysers in California. Here superheated steam is produced with a heat content, so high that it could not have been boiled off of a fresh water pool. This puzzled us until last year when a well was completed into a large body of brine in the Imperial Valley. This brine exists at close to 500°F and at a hydrostatic pressure sufficient to preclude any boiling. It is now believed by some of us that a similar pool of brine must exist below The Big Geysers area, from which the steam is emanating. If there is such a brine pool, it offers a plausible explanation of the high-heat content, for brine boils at a higher temperature than fresh water. I am now beginning to think that a similar brine pool may exist under all the geothermal basins for if it is under two of them, it is highly probable that it is under the others. The partial understanding of what we are drilling toward, and formulating a theory to explain its behavior helps guide us in our steam well drilling.

Jan 1, 1963

By Robert B. Worthington

This investigation was undertaken to develop a more efficient copper smelting practice that would help meet the increasingly stringent antipollution standards. Continuous smelting to copper and a 0.8-to 5-percent copper slag using pure oxygen has been demonstrated for several hours at a time in a unique double furnace, which was devised to overcome the heat losses inherent in a laboratory furnace. The use of pure oxygen to effect the smelting and conversion of copper sulfide concentrate in a single unit to produce blister copper and a very high S02 concentration provides a much reduced gas volume for more economical and thorough sulfur recovery. Although the process was successfully demonstrated for several hours at a time, extended test work using longer runs will be required to balance the system and to obtain test data for adequately demonstrating its technical feasibility.

Jan 1, 1973

By Valérie Léveillé

As new legislation drives to lower SO2 emissions from metallurgical plants, plant managers face the challenge of keeping their costs under control. The Cansolv® SO2 Scrubbing System has been broadly adopted in the non-ferrous industry as a cost effective solution for smelter operators to meet the new SO2 emissions targets. The Cansolv® SO2 Scrubbing System is an amine-based regenerable process that selectively absorbs SO2 from a variety of gases, including dilute smelter gases, such as furnace and converter gases. The system produces a pure, water-saturated SO2 byproduct stream, which can then be directed to the front end of a sulfuric acid plant for conversion to sulfuric acid. When deployed in a smelter complex, the Cansolv® SO2 Scrubbing System may also be used to process acid plant tail gas, allowing single absorption sulfuric acid plants to achieve emissions an order of magnitude lower than that of a double absorption acid plant with a lower capital investment. Depending on inlet gas temperature SO2 emissions in the treated gas can be controlled to as low as 55 mg/Nm3. This paper will describe some of the applications where customers have or are planning to use the Cansolv® SO2 Scrubbing System and what as well as which features and cost advantages for the treatment of smelter gases were key to the technology choice.

Jan 1, 2009

By W. F. Carew, F. A. Crossley

IT has been reported that the Ti-8 pct A1 alloy is ductile as water quenched from 800°C but brittle as annealed at 650 °C." The present, somewhat limited, investigation was undertaken to discover the cause of the embrittlement. In order to evaluate to some extent the continuity of the embrittling phenomenon, alloys of 6, 8, and 10 pct A1 were studied. Subsequent to the completion of most of this work, Ence and Margolin reported that a Ti,A1 phase exists and that two or more unidentified compounds may exist in the Ti-A1 system.' Materials, Equipment, and Techniques The alloys were prepared using Kroll process sponge of 124 Bhn hardness. In addition, some 8 pct A1 material was made with iodide titanium. The sponge-base alloys were prepared as melts of 4 lb or more by double arc melting. The iodide Ti-8 pct A1 alloy was prepared as 200-g buttons. The alloys were forged at temperatures of 980" to 1150°C. Results of chemical analyses are given in Table I. A Baldwin-Southwark 60,000-lb capacity tensile machine, equipped with an autographic stress-strain recorder, was used for the tensile tests. Standard tensile test specimens, 0.252 in. diam, were used. Standard Charwy V-notch impact specimens were tested using a -kiehle machine. specimens were sealed in evacuated Vycor bulbs for heat treatment. Powder samples for Debye-Sherrer anal- ysis were prepared by filing and screening through 325 mesh. The —325 mesh fraction was taken in an effort to concentrate a microstructural constituent assumed to be less ductile than the a phase. The powder samples were stress relieve2 by annealing

Jan 1, 1958

By Marius Jacobs

"Safety performance in many companies and even industries has stalled in the few years. Accidents rates are at a "plateau" and yet, serious accidents and fatality rates are not. In more dramatic cases, such as in the BP Texas disaster, organizations that have "exemplary" safety statistics, suddenly have a catastrophic or multi-fatality event occurring. Other classic examples are the Piper Alpha disaster and NASA’s Challenger and Columbia disasters and even the Chernobyl nuclear reactor. Looking into the root causes of these accidents provides an insight into the events and deficiencies that led up to the accident, but what are the common features in the organization’s mindset? What characterizes these organizations’ decision-making, their approach to safety and to risk and are there specific cultural features that can be delineated? The research and review presented in this paper covers a period since 1994, which started in the Australian resource industry and since then covered international events. The features of these organizations are summarized as the seven deadly delusions, based on extensiveresearch since 1997 of organizations that suffered unexpected disasters.The Piper Alpha Oil Rig disaster in the North Sea, on the 6 July 1988, was one of the most pivotal events in safety around the world. It changed the thinking and focus of governments, whole industries and led to numerous books and papers. It resulted in new legislation, textbooks and a critical self-examination by the oil and gas industry.In short, an explosion and fire occurred when a pipe started leaking gas and ignited. A temporary flange, with no safety valve, was used to block off this pipe during a maintenance operation the previous shift. The permit to advise operators not to start the pumps on this line was misplaced and lost. Several deficiencies, problems and system failures coincided. A key factor was that the water deluge system was inoperable at the time and failed to extinguish the large fire that erupted, followed by an even larger gas explosion. The accommodation unit, situated on top of the oil rig, was the main "killing field" - most men gathered here to await instructions (which never came) and where they died from smoke inhalation. Later, a large explosion of the gas pipeline from an adjoined rig exploded and killed more people.The line of events and the associated system failures are all very relevant in the analysis of the accident, and provide the only insight into what caused the accident. But much "further back", inside the organization’s culture, lurks more dark matter. The first inclination is to ask what was "deficient" in the culture. Did they not care enough about safety, or about their people? Did they have a culture where production decisions were more important than safety considerations? Did they ‘coerce’ supervisors and employees to ignore safety precautions or did they just "fly by the seat of their pants"?Not surprisingly, it is very difficult to identify the true nature of the culture in that business because in such an aftermath of death and destruction, no one dare say that the safety culture was a ‘positive one, focused and caring’ or that the company was doing well in safety and that this is only a freak accident. Indeed, there were many deficiencies in the organization’s systems and procedures, such as the permit to work system.But there are some niggling questions: How is then that the Piper Alpha Oil Rig was actually considered the company’s most productive and safest oil rig in the North Sea? Why would this rig win a safety competition, 6 months before the disaster, with the deficient permit as its most outstanding successful system?"

Jan 1, 2014

By Masami Hayashi

The Bureau of Mines estimated the cost for ,3 uranium ion-exchange recovery system using five grades of 17.0, leach solution producing 815,570 pounds of U 0? per year from an ammonium bicarbonate in situ leach solution. The system flowsheet consisted of four unit operations: (1) Multiple-compartment ion-exchange (MCIX) absorption; (2) MCIX elution; (3) precipitation of the uranium as yellow cake, filtering, calcining, and packaging; and (4) waste disposal. The total fixed capital cost of a system treating 2,000 gallons per minute of 0.1-gram-per-liter-U308 leach solution was estimated as $6,888,000. For n basic case of an MCIX system depreciating in 9 years, unit production cost of U308 was $3.51 per pound. A decrease in feed solution grade from 0.[4] to 0.03 gram per liter increased the production cost exponentially. Shorter depreciating periods significantly increased the production cost particularly for the lower grade feed solutions.

Jan 1, 1979

By P. Mark. Hawley

Development of Barrick Gold?s Pierina Gold Mine in north-central Peru requires construction of a waste dump for disposal of non-ore grade materials stripped from the open pit to expose the ore. The waste dump site is located near the open pit in a U-shaped valley that is underlain by thin colluvial and morainal soils with locally thick peats and glaciolacustrine deposits. Bedrock underlying the site consists of variably weathered volcanics. The site is subject to moderately high seasonal rainfall and significant seismicity. The geotechnical quality of the waste rock is highly variable, ranging from low quality, degradable, soil-like materials containing appreciable quantities of silt and clay, to high quality, hard, durable, blocky waste rock. A hybrid dump design concept was developed that requires in-pit segregation of high and low quality waste, and selective placement of materials in the dump to maximize stability and enhance internal and subsurface drainage. The design includes a rock drain beneath the dump along the axis of the valley and a series of connected finger drains. Extensive peripheral diversions and stormwater control measures to inhibit infiltration of precipitation are also included. This paper discusses the unique challenges presented by the site and waste materials, the design methodology and stability analyses, and planned monitoring systems.

May 1, 2002

By David Van Horsen

Big Creek Tunnel 2, constructed in 1912, is located in the Sierra Nevada Mountains of California, east of Fresno. It is horseshoe and circular shaped with a 3.6m (12ft) diameter and extends 6.6km (4.1mi). Historically, tunnel performance suffers from highly jointed rock and low cover. In 2003, leaks were observed surfacing through outcrops of highly jointed graniodiorite, and subsequently investigated by visual inspection, joint mapping, ground penetrating radar, and a water-tracing survey. Several grouting targets were identified as a result of these investigations. Cement grouting was used to fill void spaces, broken rock and open joints expected to exist behind the concrete and steel liners. Project work consisted of grout hole drilling through the existing concrete liners, and grout placement through squeeze packers supplied by standard grout hose and portable grout plants. Grout pressures were typically 20?30 psi. Grouting was completed in 16 days with a total of 1,550 sacks of Type II/III grout placed at the three likely leak source areas. No grout was observed exiting the tunnel and the leak was stopped.

Jan 1, 2008

By D O’Dea, B Godel, T Honeyands, B Ellis, T Harvey

X-ray computed tomography (XCT) is a non-destructive technique that allows the exploration of the internal structure of solid objects in 3D. Over the past ten years, the combination of XCT with more conventional 2D techniques and quantitative 3D image processing and analysis (commonly referred to as digital rocks) has allowed us to address some of the most challenging problems in ore deposit studies. The range of X-ray energies used in XCT allows the X-rays to be transmitted through complex and dense materials including iron ores (eg sinters, lumps, granules). Recent high-resolution XCT scanners have the ability to generate multiscale (25 down to 0.3 µm voxel size) imaging of a given sample enabling the characterisation of 3D textures across a range of scales. This paper will focus on the application of digital rocks to iron ore sinter particles (using filtered polychromatic X-ray beam). The paper is divided into three parts and includes: i) details on the methodologies including their benefits and limitations and the effect of spatial resolution; (ii) the quantification of pore network topology and pore characteristics (eg open versus closed pores, pore size distribution and pore morphologies; degree of connectivity of the pore network and its tortuosity); and (iii) the evaluation of the technique to characterise various phases within the material and quantify 3D mineral textures.CITATION:Godel, B, Ellis, B, O’Dea, D, Honeyands, T and Harvey, T, 2017. Digital rocks for iron ore sinters – towards a D quantification of sinter textures, in Proceedings Iron Ore 2017, pp 529–534 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Edward W. Parsons

Conventional rock-bolt anchors often fail when installed in weak formations. The purpose of this work was to develop an anchor that would utilize an explosive charge to secure anchorage in any type of rock. Laboratory work to develop a rock-bolt anchored by explosive forming was initiated using rock-bolt models which had a drilled explosive chamber and were composed of various metals. This was followed by the use of several types of seamless tubing which were expanded with a water-coupled explosive capsule. By attaching a length of solid bolt to the anchor tube, a prototype explosive-anchored rock bolt was made. More than 150 laboratory models were expanded during this phase of development, During two field tests in underground mines (A and B) and one in an open- cut mine (C), 87 explosive-anchored bolts, 9 slot-and-wedge bolts, 2 bolts anchored with expanding grout, and 28 expansion-shell bolts consisting of three types of shells were installed and subjected to pull tests. The field tests were run to determine the effects of variables such as the amount and placement of the explosive charge, design changes in the bolt, and the effect on anchorage of different pull-test techniques. The field tests revealed the following: Mine A. The explosive-anchored rock bolt was feasible, but changes were necessary in bolt materials and in some details of bolt design. Mine B. The design and materials of the bolt gave excellent results in hard fractured rock, but no information was obtained concerning variations in the dimensions of the anchor unit or in the explosive charge. Nine C. Varying the explosive charge to produce a beaded surface on the bolt tube and tightening of the anchored bolt before pull-testing were found to increase significantly the anchorage obtained in soft ground.

Jan 1, 1963

By J Cornejo, A Pinochet, C Caviedes

The ore extraction rate and the incorporation of new areas are key operational parameters. In massive deposits mined by caving techniques they both control the cave back geometry, which is mostly responsible for the induced stress state around productive levels. Early detection of deviations from admissible geometries will prevent stability problems related to geomechanical hazards, helping to improve safety and working conditions and reduce the potential for lost reserves.This paper describes a mine planning tool currently in use at the El Teniente mine. This tool involves the control of the cave geometry based on rules that have been defined as a result of different studies and experience collected during the operational history of the mine.This mine planning strategy achieves an extractive mining process with lower risk than conventional planning methods, ensuring ore reserves extraction if followed as planned while reducing unexpected changes in mining sequences.CITATION:Cornejo, J, Pinochet, A and Caviedes, C, 2016. Geometric control for strategic mine planning at El Teniente Mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 191–196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

An accelerated and coordinated program of coal research is believed by many to be a necessary step in assuring coal's proper position in the expanding energy market. The President's Advisory Committee on Energy Supplies and Resources Policy, for example, made the following recommendation: We recognize that coal is a great national asset and endorse a cooperative study to determine what research and development could be undertaken. The coal industry and both Federal and State Governments should participate in this study and its costs. Representatives of the coal industry have agreed that such a study should be initiated. Accordingly, Felix E. Wormser, Assistant Secretary - Mineral Resources, United States Department of the Interior, requested the Bureau of Mines and Bituminous Coal Research, Inc., to conduct a survey of current research on bituminous coal. In addition to this survey, studies were made to determine research projects that would be of value to the coal industry.

Jan 1, 1956

By Mayworm Luiz, Mantovanelli Mauro, Merisio Everaldo, Oliveira Edgar Adrian, Vieira Estéfano Aparecido, Kaneda Kazuyuki

Os filtros da estação de tratamento de água do circuito spray da planta de lingotamento contínuo apresentam problemas de desempenho quanto a vazão, gerando perda de produtividade do processo de produção de placas da ArcelorMittal Tubarão. Na etapa de filtração da água de recirculação utilizada no circuito de spray, ocorre redução da vazão com o tempo de operação não atendo a necessidade do processo. Existe uma divergência de especificação de projeto uma vez que o projeto original visa tratamento de água potável e não água do sistema direto de lingotamento, uma água com alta concentração de sólidos em suspenção e óleos&graxas. Para recuperar a vazão da água filtrada, é necessário aumentar a frequência de contra lavagem, melhorando a passagem da água e limpando os leitos, porém a alta frequência de contra lavagem torna-se uma complicação para operação da ETA, não garantindo a estabilidade da operação. O objetivo deste trabalho foi identificar e propor soluções para os problemas de vazão dos filtros de forma a garantir a especificação nominal de projeto (1380 m³/h / 5 filtros) e consequente estabilidade operacional do sistema. Foram feitas avaliações em laboratório para identificar a composição ideal do leito filtrante assim como sua distribuição granulométrica, além de modificações internas do filtro e das crepinas utilizadas no sistema de contra lavagem. Após as modificações, o filtro está operando por quase um ano conforme especificação, garantindo a vazão de filtração e prolongando o tempo de contra lavagem de 6/6 horas para 15/15 horas.

Oct 1, 2019

By T. J. Ballard, Austin B. Clayton

"The Union Copper mine is in the Gold Hill district, Rowan and Cabarrus Counties, N. C.The mine was discovered in 1799 and first worked as a gold mine; but copper was encountered at depth, and the property became an important producer of copper. It is estimated that the mine produced 5,000,000 pounds of copper before operations were discontinued in 1907.As part of the strategic minerals program, the Bureau of Mines conducted a development project on the property from July 1943 to November 1943. Eight diamond-drill holes, totaling 2,500 linear feet, were drilled to delineate the ore body. Analyses of 205 core samples were made.Tabulations of sample analyses and drill-hole logs are presented in this report.The project work embodied in this report was under the immediate supervision of Austin B. Clayton, project engineer, and the general supervision of H. B. Ewoldt, district engineer for North Carolina and Tennessee. The preliminary report, written by Austin B. Clayton, was revised and the various figures redrawn for publication by T. J. Ballard under the general supervision of M. H. Kline, chief, Raleigh Branch, Mining Division.Acknowledgment is due the Metallurgical Branch for analytical determinations of the samples.The mine property is 1.5 miles southwest of the village of Gold. Hill, N. C. (fig. 1). Gold Hill is on U. S. Highway 52 between Salisbury and Albemarle and on a branch line of the Southern Railway. The latitude is 350 30' and longitude 80° 21 The tract consists of 553-1/2 acres in Cabarrus and Rowan Counties.A tentative list of the surface-rights ownership is as follows: William Hoy Barringer - 16 acres, A. W. Tucker - 1 acre, Frank Wagoner - 4 acres, and George Barringer - 3-1/2 acres, in Cabarrus County; A. W. Tucker - 2 acres, H. N. Hedrick - 54 acres, and William Atkins - 473 acres, in, Rowan County, N. C.The mineral rights are owned by Alfred Rossiter, Alice R. Hesslein? and the estate of the late Bella Rosenblatt. The attorneys for the owners are Neidle & Taylor, 6 East 45th Street, New York City.The Union Copper mine is in the Cold Hill mining district of North Carolina where gold was first discovered in 1799. The upper parts of the veins in the district were first worked for gold; however, the increase in the sulfide content of the veins with depth rendered the amalgamation process for gold recovery ineffective, and the mines were closed.The period of greatest activity at the Union Copper mine was from 1899 to 1906. At an earlier period the oxidized and leached part of the lode near the surface was mined from a working known as the ""big cut,"" the reported yield of which was $300,000 in gold.3/ The mine has not been operated since 1907.J. T. Pardee3/ lists the probable value of the production of the Union Copper mine as $1,050,000, of which about $675,000 was the value of some 5,000,000 pounds of copper produced."

Oct 1, 1948

The steps for the beneficiation of iron ores differ from ore to ore, depending on the mineralogical phases of the particular iron ore and the nature of the association of the gangue minerals with iron oxide in that ore. The extent to which the beneficiation can be undertaken economically depends both on the amount and the nature of the gangue. The analysis of the phases present in an orebody optimises the mining and process operations (separation, beneficiation, sintering, etc).X-ray diffraction (XRD) provides qualitative and quantitative information about the main ore phases as well as the gangue mineralogy and the amorphous content present in a sample. In addition, modern quantification methods such as Rietveld refinement allow the calculation of the distribution of elements in solid solutions such the substitution of Fe with Al in goethite or hematite.The use of high speed detectors has made XRD an important tool for grade and process control. Finger printing of XRD data can facilitate multi-dimensional mapping of ore deposits and drill cores, identifying regions of favourable mineral compositions. Grade control using XRD can be completely automated and controlled remotely.The two case studies in this paper demonstrate how XRD and finger printing can be used for grade control, process optimisation and quality control of a goethitic and a magnetitic iron ore. The enormous potential of XRD as an inexpensive, reliable tool, useful in the characterisation of iron ores will be demonstrated.CITATION:K÷nig, U, 2013. Application of x-ray diffraction to iron ores - potential implications for grade control and downstream processing, in Proceedings Iron Ore 2013 , pp 275-280 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013