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By J. R. Goode

Rare earth elements (REE) and their compounds are critical ingredients in numerous necessities of modern life including: the permanent magnets used in electric motors, generators, speaker and hard drives; high performance automobile tires; catalysts; phosphors; optical glass; etc. World production of REE in 2014 was about 110,000 t with about 98,000 t/a being “Light” (LREE) and the balance “Heavy” (HREE). Unlike other mined commodities, the majority of the LREE produced in the world is a by-product and that from a single iron ore mine in China. The balance of the LREE production comes from four REE-only mines, two in China, one in Australia and one in the USA (now on Care and Maintenance basis). The LREE operations comprise very unusual flotation processes and complex hydrometallurgical plants. In contrast, most of the HREE come from a multitude of small in-situ leach operations exploiting a single, dispersed deposit in China using hydrometallurgy alone. All of the current REE operations produce an intermediate mixed REE product that must be separated to yield the high purity, individual, REE required by the market. This paper describes the processes being used to produce LREE and HREE intermediate products and the separation plants used to make the high purity REE compounds that are key ingredients in the magnets in earbuds, turbines, and automobiles; catalysts used in the production of gasoline, and so on.

Jan 1, 2016

By J. C. Kingston

Introduction The sliding-form method of erecting concrete structures was first devised and used in the early part of this century by the Sante Fe Railroad Company for the erection of a grain elevator at Santa Fe, New Mexico. A somewhat related principle has been employed for a number of years in shaft lining work and, to our knowledge, was perfected in Butte, Montana, but until the building of the concrete headframe at the Jeffrey mine of the Canadian Johns-Manville Company, Ltd., at Asbestos, Que., the method, as applied to surface structures, was quite foreign to the mining industry in Canada. The current shortage and cost of structural steel shapes has no doubt contributed more than any other single factor to the investigations that have led to the use of reinforced concrete as a headframe building material. Mining men in western Quebec and northern Ontario have shown a great deal of interest in the design and construction of the headframe at the East Sullivan mine in Bourlamaque township, Que., and we have had many queries regarding the methods used and, in particular, for an explanation of the sliding-form principle. This article is written in an attempt to set forth the conditions which were to be met; to explain the construction methods used, and to discuss the economy of concrete headframes as compared with the conventional steel structures with which the mining fraternity is familiar.

Jan 1, 1949

By Khamis Y. Haramy

This Bureau of Mines paper describes the use of the borehole shear tester (BST) In mines. Assembly and procedure sections explain how the equipment is assembled and used properly. Schematics of the BST, limitations, test hole specifications, data recording and calculations are all explained briefly, and an example of the data collecting and calculations is given to assist understanding.

Jan 1, 1981

To reduce the exposure of mining machine operators to respirable dust. Approach: A protective curtain of filtered air is blown down around the operator's head, from a manifold mounted on the machine canopy. How It Works: Mine air is drawn into the system through a filter which removes respirable dust. The filtered air enters a centrifugal blower which pushes it through a flexible hose to a manifold mounted on the canopy above the operator. Air leaves the manifold through a perforated plate and flows down around the operator's head. A photograph of an installed system can be seen in Figure 1. The second photograph, Figure 2, shows the sys-tem components. An important advantage of this dust protection system is that it is not worn or carried, or in any way connected to the operator. It is therefore not uncomfortable, encumbering, or

Jan 1, 1976

By G Liu

Seventy-nine gold deposits and prospects have been discovered in theJiamusi region of northeast China, and constitute one of the most important gold metallogenic belts in China. All these endogenic gold occurrences can be subdivided into three main deposit types: 1. porphyry related; 2. metamorphic-intrusive hosted, and 3. sediment-hosted deposit.   The first two types of gold deposit are spatially and temporally related to Mesozoic Yanshanian granitoid intrusions with hydrothermal activity channelled along crustal-scale fissures. The ultimate cause of the Yanshanian magmatism is considered to be the subduction of Pacific oceanic lithosphere beneath the Eurasian continent. In contrast, the chemical sediment-hosted deposit is typified by the Dongfengshan gold deposit, and genetically related to Proterozoic sedimentation and Mesozoic igneous activities.

Jan 1, 1995

By K. L. Paciorek

Organic materials utilized as cable Jacketing, cable insulation, standoffs, insulating boards and potting compositions were identified and d literature survey performed to obtain the required thermal oxidative and moist tracking data. Thirty representative compositions were procured and subjected to thermal and moist tracking evaluations. Tracking was found to invariably result in ignition or glow of the test specimen. Influence of parameters such as electrolyte strength and composition, temperature, conductor spacing, and electrode material were investigated. Volatile s produced by selected insulators on thermal oxidative and electrical stress were identified, quantitated, and their potential impairment action upon a current interrupter assessed.

Jan 1, 1980

By D. Lawrence, H. Lawrence, G. Saevil

Plant operators in the mineral processing industry have been implementing expert systems for several years now, with the intent to increase production and reduce costs. Most systems have been installed on grinding circuits of some type and have proven that the technology is viable in that application. However, few applications on other processes have been attempted for various reasons, such as lack of reference sites, complexity of the process, lack of suitable measurements and lack of confidence in the technology. The successful application of an expert system on an Alumina Calcining kiln is the first such application in the West Indies Alumina Company (Windalco), and demonstrates how this technology can be successfully applied to other processes. The key objective of an expert system is to optimize the process. To achieve this the process must first be stabilized, followed by optimization of the operating parameters. The steps taken by this expert system to optimize the process are: • Check for abnormal conditions and deal with them using a prioritized set of special actions. • Use a selection of rule blocks to stabilize the process. • Once the process is stable, achieve additional benefits through further optimization of the process. The potential benefits that a user can expect to achieve through installing an expert system can be assessed on the basis that performance will improve from that of an "average operator" to that of the "best operator" performing at his optimum for 24 hours a day, every day. The quantifiable process benefits include: • Increased production • More consistent product quality • Reduced operating costs • Reduced standard deviation of key variables • Consistent plant operation The success of this project was measured in several ways: project implementation, realised economic benefits, and realised non-economic benefits. With a commitment to maintain the system over the long term, the longevity of the system is assured and will become an important part of the Alumina Calcining control strategy at Windalco. This paper discusses the various phases of implementing the ABB Expert Optimizer expert system, what the benefits were and the procedure that is in place to maintain the system to ensure continued long term success.

Jan 1, 2002

By Sandra Lúcia de Moraes

O presente trabalho visou contribuir para o melhor entendimento do mecanismo inerente ao uso de agente coloidisante/dispersante no processo de pelotização de concentrado de minério de ferro. Avaliou-se a influência dos agentes coloidisantes em comparação aos aglomerantes Peridur e bentonita. Para este fim, foram realizados ensaios de bancada visando a identificação de possíveis ações destes agentes no grau de dispersão das misturas, bem como a sua influência na liberação/aglomeração dos finos. Os resultados destes parâmetros foram confrontados com os resultados de caracterização das pelotas confeccionadas com os diferentes agentes pelos quais foi possível identificar que os dispersantes tem forte atuação sobre o conteúdo de finos do concentrado de minério de ferro. A ação principal se dá pela remoção das partículas ultrafinas que recobrem os grãos mais grosseiros presentes na amostra e as dispersam, no caso dos dispersantes, aumentando a disponibilidade do conteúdo de finos <4 µm, principalmente os finos <1 µm (coloides). No caso do aglomerante orgânico, observa-se também essa ação, no entanto, os finos presentes são aglomerados na faixa entre 26 e 4 µm.

Aug 16, 2017

By R. S. Dean

In general, the Division conducts investigations relating to the treatment of ores and metallurgical products from the condition to which they are mined to the refined metal. At the object of conserving natural resources and eliminating waste by furnishing information on current methods of metallurgical practice making fig fundamental studies of metallurgical processes and developing new processes and alloys to the point of demonstrating their or value. Office of the Chief Engineer The functions of the technical units of the Office of the Chief Engineer are indicates

Jan 1, 1941

By Thompson D. R, Milton R, Perry K. M A

From the Department for Research in Industrial Medicine (Medical Research Council), The London Hospital; and the De Havilland Aircraft Company:M.R.C. INVESTIGATIONS IN 1936In 1936 the Industrial Pulmonary Disease Committee of the Medical Research Council investigated both clinically and radiologically a group of fifty workers who had been exposed for a number of years to the inhalation of alumina in the reduction factory of the British Aluminium Company. The results are shown in Table 1.They also considered the sickness records of all the workers (Hill, 1936), as compared with those in other parts of the factory (Table 2).

Jan 1, 1945

Vein swarms in metamorphic terranes such as the Otago Schist Belt, New Zealand provide evidence of past hydrothermal flow systems leading to fault initiation and reactivation. A major episode of hydrofracturing and fluid redistribution occurred during early Cretaceous exhumation of the schist belt. As a result, presently exposed lower greenschist facies greyschists in NW Otago are pervaded by abundant quartz-filled hydraulic extension fractures with associated normal faults hosting quartz¦scheelite¦gold mineralisation. Once the effects of Cenozoic folding have been removed, a regional subhorizontal schist foliation contains an aligned array of subvertical hydrofractures striking NNW, striking parallel to a set of low-slip conjugate normal faults; the array extends over an area >1500 km2 and over a depth interval >5 km. The hydrofracture array comprises a mesh of interlinked extensional-shear and pure extension veins. These veins show mutually cross-cutting relations. Extensional hydrofracturing apparently preceded the development of major throughgoing normal faults. Low-displacement normal faults are infilled with laminated quartz (¦ scheelite) veins (

Jan 1, 2002

By D. Bogunovic

The U.S. coal mining industry consumes a significant amount of energy, primarily diesel fuel and electricity. The continuous global increase in energy demand, high energy prices, and environmental issues related to carbon dioxide emission represent a substantial challenge for the mining industry. This paper presents a result of research work on development of an integrated data environment system for analysis and control of energy consumption in a surface coal mine. A case study on an operating surface coal mine is carried out to demonstrate the practical application of the developed system. The research work presented here may be used by mining professionals to help provide the answers to the crucial questions of when, where, and how much energy is being used. This developed system represents a framework for efficient management of energy consumption. Key words: surface mining, coal, energy consumption, Information System.

Jan 1, 2009

By A. Redman

Aquatic organisms are sensitive to free cyanide (HCN) though the presence of certain metals that can form stable complexes and thereby reducing both the amount of bioavailable cyanide. Recent work has suggested that consideration of HCN rather than total cyanide can provide the basis for water quality criteria. Cyanide is often present in complex effluents that affect speciation and bioavailability. We have developed a model to predict the speciation of cyanide in complex effluents and have shown that this model can predict the toxicity of metal-cyanide complexes in terms of HCN. This study evaluated available cyanide toxicity exposures with this model to assess the role of water chemistry (e.g., metal-cyanide interactions) on the observed. Toxicity endpoints based on total cyanide ranged over several orders of magnitude for a variety of metal-cyanide mixtures. However, predicted HCN concentrations among these same tests described the observed toxicity data to within a factor of 2. Aquatic toxicity can be well described using HCN though in certain metal-cyanide mixtures toxicity was jointly described by HCN and elevated levels of bioavailable metals. This work was performed in support of an industry-sponsored reassessment (Gensemer et al 2006) of the U.S. EPA water quality criteria for cyanide (EPA 1985) using free cyanide as the basis for the re-calculation. The work presented in this manuscript presents technical support for using free cyanide as the preferred basis for this recalculation.

Jan 1, 2011

By Gordon King

The City of Atlanta Water Department required the construction of a two sludge tanks and a wet well at the existing Chattahoochee Water Treatment Plant. Western Summit won a design build contract to build the project and proceeded to evaluate the wet well size options, and construction procedures. The final design required the construction of a 1 million gallon tank. The proximity of the underground tank to adjacent roads and existing plant structures ruled out laying back the excavation. As a result a tied back sheet pile retaining wall was initially proposed.

Jan 1, 2003

By Steve Kral

Borates are minerals that contain boron. Trace amounts exist in rocks, soil, water and people. Boron-containing ores are rare and U.S. Borax, a subsidiary of Rio Tinto Borax, controls one of the world’s two world-class borate deposits. Through its global systems of mines, refineries, ports, sales offices and distribution centers, the company supplies nearly 45 percent of the world’s demand for borates. Borax has been mining borates in California for more than a century. This year the company celebrated 131 years of continuous business in the Golden State and 76 years at its operations in Boron, the site of California’s largest openpit mine. It also has mines and refineries in Argentina, refineries and ship-ping facilities in Europe and technical staff in the United States, North and South America, Europe and Asia Pacific. So, with the 130±years of borate mining and processing experience behind it as well as its global marketing and distribution centers, there is very little that Borax does not know about borates.

Jan 1, 2003

By Frederick C. Trutt

This report is intended as a reference for personnel interested in the computer anlaysis of coal-mine-electrical-power systems under either normal operating conditions or fault situations. The procedures developed for this purpose are described and implementation considerations are discussed with respect to the mine-power system. Considerations for choosing a solution technique and a number of examples are included. Procedures described include the Newton-Raphson iterative technique for the analysis of normal operation as well as a non-iterative Z-bus technique for analysis of unbalanced or balanced faults. During program development, strict attention has been given to the inclusion of core and/or time saving techniques such that these algorithms may be implemented on small as well as large computers. Program languages include FORTRAN IV for batch processing applications and APL or BASIC for interactive applications.

Jan 1, 1981

By B Hartmann

In 2003, Independence Group NL purchased the Long Shaft Nickel Mine complex (Long) in Kambalda, Western Australia. Lightning Nickel, the nickel operating arm of Independence Group, faced considerable challenges operating the mine, with the most significant challenge being able to prove that the remnant ore at Long and the associated orebodies could be mined safely and efficiently. Given the seismic history at Long, the magnitude of these challenges could not be underestimated. In an effort to achieve 100 per cent extraction of the flatter orebodies, traditional methods such as room and pillar were dismissed. A method consisting of transverse sills, butting into each other was proposed. To stop fill material from the first sill rilling into the adjoining sill, it was proposed to backfill the sills with pumped cement fill. The capital cost of the fill plant was estimated to be in excess of $1.5 million and the cost for cement alone was $1.0 million per annum. Shotcrete was already an extremely useful tool in dealing with the widely variable stress environment, but was to be used in an innovative manner that would enable the full extraction of a tabular section of the Victor South orebody. A layer of shotcrete, approximately 100 mm thick, was to be sprayed on the up dip wall of the initial development sill. The sill was to be backfilled with ænormalÆ development waste and ætoppedÆ with sand backfill. The next sill, ie slightly up dip and alongside, was to be mined along the shotcrete boundary wall. With respect to wall stability, the premise was that the shotcrete wall would stay in place and prevent the backfill (development waste and sand) from rilling into the adjoining development. It was also proposed that any breaches of the shotcrete wall would be repaired using shotcrete before substantial inflow of backfill into the ænewÆ development. This paper describes the development and implementation of this mining method, as well as some of the associated financial aspects.

Jan 1, 2008

By B S. Utting, W J. Cowie

The alluvial gold industry of New Zealand is based on the placer deposits in Otago and on the West Coast. Production from these since discovery in the 1850s has been an estimated 480 t (15 Moz) of gold. Annual output has expanded continuously since 1980 and is expected to be over 2 t of gold for 1989. Following a historical review, the characteristics of typical operations, which use hydraulic excavators and mobile trommel units are discussed. Descriptions are then given of alluvial activities in Otago and on the West Coast.

Jan 1, 1990

By Walter I. Paniagua

Drilled shafts and precast concrete piles were installed for the foundation of several structures in a reconfiguration project of a refinery in Minatitlan, Veracruz, in the Gulf of Mexico. The soils are alluvial deposits of flat land from the Coatzacoalcos River, which are embedded with layers of sand, soft clay, and peat. As part of a QC/QA program, load tests, both static and dynamic, axial and lateral, were performed. In this paper results of 32 axial tests are presented, in which typical load-displacement curves were measured at the top of the foundation elements; from the interpretation of these plots, data were recorded for ultimate side shear and in some cases for end bearing capacities, which are compared with the theoretical results of the final stage of the foundation design. The comparison shows that under allowable loads, side shear determines the bearing capacity of piles, even when the tip is embedded in a hard layer. Underestimation of the side shear is evident; therefore design criteria, as well as the methods used for obtaining soil parameters, should be reviewed.

Jan 1, 2007

By E. D. Calvert

Molybdenum has been successfully cast into static and rotating molds in conventional equipment used for casting titanium and zirconium. Melting was accomplished by using an arc potential of 36 to 40 volts with a current of 10,000 amperes. Pouring efficiency, after a skull had been formed in the crucible, averaged 70 percent. Techniques are described by which four successful castings were made. Tensile properties on specimens cut from one centrifugally cast tube averaged: Tensile strength, 39,800 p.s.i.; yield strength (0.1 pct. offset), 35,300 p.s.i.; elongation, nil; reduction in area, nil; impact strength, 2 ft.-lb.; hardness DPH (diamond pyramid hardness) 180. Mold reaction was not evident in shapes cast in machined graphite. This was not true, however, for rammed graphitic-base molds.

Jan 1, 1960