Search Documents

By Donald C. Strimbeck

The Bureau of Mines designed a down-fired refractory-lined combustor that efficiently burned pulverized coal to produce a gas suitable as working fluid for an open-cycle gas turbine. The gas contained relatively little carbon, so the load on the ash-separation equipment was significantly reduced. Moreover, reduction in carbon content of the gas increased the average density of the solid particles making them more amenable to removal by centrifugation. Centrifugal-type separators failed to remove sufficient ash; however, to limit blade wear enough to achieve operating periods generally deemed necessary for commercial practicability.

Jan 1, 1969

By Joel T. Werner

Tire costs represent one of the highest controllable costs in open-pit mining, accounting for approximately 10% of mining costs. Tire monitoring technology has evolved rapidly in recent years and is emerging as a viable tool for extending tire life and reducing costs. The majority of the major tire manufacturers and several independent companies are in various stages of developing monitoring systems that capture and store vital tire data. Previously this information had only been accessible when the vehicle passed a fixed point in the mine, or when mine personnel manually downloaded the data. Integrating this technology with a mine management system enables remote collection and management of trend and alarm data. Mine personnel can now monitor a tire?s health parameters at any time, anywhere on site, regardless of the vehicle?s location. Anomalous tire conditions can be detected early and corrective actions taken. This information can then be integrated with other major onboard systems, operating conditions, and geographical information. Tire monitoring no longer exists as a stand-alone technology, but has evolved into an important integrated tool for mine operators. This paper will review the current status and benefits of integrating this emerging technology with a real-time mine management system.

May 1, 2002

By M. C. Malamphy

A general description of the activities and results of bauxite investigation by the Bureau of Mines at its bauxite project in Saline and Pulaski Counties, Ark., has been given in Report of Investigations 4251. The factual data obtained during the project are reported in a series of Reports of Investigation beginning with No. 4251, of which this is the fourteenth. The data are accompanied by maps showing the location of holes drilled and the deposits developed. Each area upon which work was done is reported by half townships. Each bauxite deposit investigated was assigned & name and a number for ready reference and identification, and its location and name are shown on the appropriate half-township map. The description of each half township is followed by a description of each deposit developed in that half township. The 14 half-township maps and 77 detail maps of the bauxite deposits in this series of reports give the locations and numbers of all the holes drilled except the deep holes drilled to test geophysical anomalies. The locations of those holes are shown on figure 13 in volume 1. The descriptions of the deposits developed are followed by complete detailed logs of the drill holes. Many of the widely spaced exploratory holes did not discover bauxite of minable thickness and grade. The pertinent information obtained from the widely spaced exploratory drill holes has been summarized and tabulated, and a table for each half township is given with the discussion covering that area.

Jan 1, 1948

By C. D. Anderson

A variety of processing technologies exist for recovery from both primary and secondary sources of rhenium. Currently, there are no known primary rhenium deposits, thus, the method in which primary rhenium is produced is dependent on the commodity of which it is a byproduct, e.g., copper, molybdenum, uranium, etc. In addition, focus on the recovery of rhenium from secondary sources, such as alloy scraps and catalysts, is continually growing. This paper presents a review of both primary and secondary processing technologies for the recovery of rhenium. Key Words: Rhenium, Ammonium Perrhenate, Extractive Metallurgy

Feb 27, 2013

By A. Bamber

Canadian leadership in a global mining context will depend not only on entrepreneurship and best practice but also on technological innovation. This paper argues for more ambition and commitment to R&D for technological innovation in Canadian mining. It focuses on underground hardrock mining, where past R&D initiatives have simply not stood the test of time, and it is important to examine why. Concerns arise because industry’s commitment to R&D has not been sustained over time. Innovation through exploration, processing, and environmental technologies has been more significant. Meanwhile, R&D capacity and synergies in government institutions and universities have not been exploited. There is a need for more commitment, coordination, and collaboration by industry, governments, and universities. This paper examines some corporate models that have achieved sustainable innovation, along with some that have not. A strategy for innovation is discussed that relates to culture, commitment, coordination, and collaboration.

Jan 1, 2005

By Christopher J. Pacitto

This paper presents a case history of an engineered, monitored, and tested program that provided an effective and satisfactory basis for the completion of pile foundations for Twin Dolphins 1 at La Peninsula Condominiums located in the Isles of Capri in southwest Florida, U.S.A. An 8-story building (withl-story parking underneath) along with recreational facilities (such as a swimming pool and tennis courts) had been planned for final construction. Following an evaluation of various foundation alternatives, a precast prestressed concrete (PPC) pile-supported system was selected. The building foundations were designed for pile capacities of 445kN (50 tons) and 890kN (100 tons) in compression and 133kN (15 tons) in uplift. A test pile program was performed to provide site-specific pile driving data, verify design assumptions, determine production pile lengths, and evaluate pile driving criteria. A total of 24, 356 mm (14-in.) square, 19.8 m (65 ft) PPC concrete piles were driven and dynamically load tested utilizing a Pile Driving Analyzer (PDA) within the building limits. Dynamic monitoring during probe pile installation and restriking was performed to estimate the ultimate capacity of the piles and to evaluate driving stresses during installation. CAPWAP analyses were preformed on PDA data to better estimate pile capacity, resistance distribution, and predict pile freeze (increase in pile resistance with time) and thus optimized the production pile lengths. Upon completion of probe pile installation, 12 of the probe piles were tested using the Pile Echo Tester (PET) function of the Pile Integrity Sonic Analyzer (PISA). PET testing was performed to evaluate the integrity of piles which had exhibited high driving stresses during PDA testing. Information gathered during the probe pile driving program was effectively utilized as part of the overall quality control program to install a total of 539 PPC piles (including 24 probe piles) within the building limits at the project site to depths ranging from 9.1 to 19.8 m (30 to 65 ft) below the existing ground elevation as part of the foundation support system. Prior to installation of probe or production piles, a termination criterion was established using 1-dimensional wave equation analyses in addition to the design pile embedment requirement. The predicted pile capacities compared very well with the capacities from the CAPWAP analysis for probe piles. Use of geotechnical instrumentation and PDA assisted technology enabled each foundation support element to be constructed to its optimum capacity and at optimum cost. Furthermore, by using PDA the consultant was able to quantify a difficult to measure geotechnical phenomenon termed "pile freeze" which eliminated costly overdriving and unnecessary splicing of piles.

Jan 1, 2002

This paper presents a study about reopening of a quarry near to the geothermal region of Kntahya, Turkey. The production method was gallery blasting which resulted in very high ground vibrations. Therefore the quarry had been closed down by the local authorities about 12 years ago due to possible damages to the geothermal resources. In order to reopen the quarry, reserve estimation and production planning studies needs to be carried out as well as applying environmentally sensitive production method. The result of reserve estimation studies showed approximately 12.5 Mt reserve in the area. The market studies indicated that annual production of 600 000 tonnes could be sold. These results justify to reopen the quarry. In order to overcome environmental problems, bench blasting production method instead of gallery blasting has been planned. This method enables to design a drilling blasting pattern that will almost result in no ground vibrations.

Dec 6, 2010

By C. W. Owings

A few of the more progressive mining companies have taken precautions to safeguard employees or man-trips. Specially constructed men-cars -have been provided with special devices or mechanisms to stop the cars on slopes, if the hoisting cable should break. Cars have been equipped with safety chains to connect and hold them together if a coupling should break. Steel frames covered with heavy wire netting have been placed over cars to reduce injuries to the riders from roof fails on slopes. A safety cable passing from the front car to a point above the cable socket on the slope hoisting cable is used frequently as a precaution in case the socket loosens o the main cable breaks at the socket. Such devices are commendable, but the percentage of man-cars and man-trips protected is relatively small - entirely too small. Man-trips that travel level haulage roads are rarely protected safety devices, and haulage roads are seldom inspected by mine officials to determine the condition of roof and ribs.

Jan 1, 1935

By David L. Shearer

INTRODUCTON James Howden first secured an order for two Service Tunnel Boring machines in November 1986. These Tunnel Boring machines were 5.7 and 5.4 metres in diameter and the full length including back up was 215 metres. Manufacture commenced in December 1986 at the Glasgow factories of James Howden & Company with the deliveries to site of the machines in September 1987 and March 1988 respectively. In December 1987 two further orders were secured for the land running tunnels at 8.7 metres diameter. This paper presents some of the challenges in building tunnel boring machines for the Eurotunnel project between Britain and France. The general specifications of the Tunnel Boring machines and length of drives are shown in Appendix 1. DESIGN PARAMETERS The specification given by the Consortium TML on behalf of their client Eurotunnel cleary indicated that cutting of the face should be concurrent with the building of the precast concrete lining rings. In order to do this a telescopic machine was thought to be the best solution. Ground conditions were described as chalk marls of homogeneous nature with the possibility of friable areas and some revelling. A shielded type TBM with open cutter head was chosen together with a telescopic section and a rear

Jan 1, 1989

By Lívia Lopes de Oliveira Goulart

Visando garantir o nível de qualidade dos produtos e o controle do processamento do aço para atender aos requisitos dos clientes e das normas técnicas aplicáveis e manter-se competitivo no mercado de aços longos com redução contínua de custos, um dos grandes desafios das aciarias elétricas é promover o aumento do rendimento de suas ferro-ligas melhorando ao mesmo tempo os processos de desoxidação e dessulfuração, além da limpeza interna do banho. Este trabalho teve como objetivo avaliar o efeito da adição de carbureto de cálcio durante o vazamento das corridas do aço 1026-D nestas variáveis, através da análise estatística e termodinâmica de dados de corridas experimentais, com e sem adição de carbureto de cálcio. Foi demonstrado que a adição desse insumo melhora de forma significativa os parâmetros metalúrgicos de qualidade do material e reduz o custo de transformação para a fabricação desse produto através da redução do consumo de ferro-ligas.

Aug 16, 2017

By James W. Myers

The Bureau of Mines studied factors affecting ignition of coal mine refuse and on methods for control of burning. Laboratory experiments showed that air permeates more readily through segregated than through nonsegregated refuse and that air permeability is greater through coarse than through fine particle refuse. Minus 3-1/4-inch refuse ignites spontaneously more readily than minus 1/4-inch refuse. The burning of a 1,000-pound conical coal pile was con-trolled by capping with an 18-inch-thick layer of minus 1/4-inch refuse containing 37 percent combustible. In field trials, the burning of refuse at operating mines was controlled by capping with a layer of fine refuse. Water, applied as a spray or by injection, quenched surface flames and cooled the burning waste. Inspection of refuse piles at operating mines showed that the spontaneous ignition tendency is affected by the exposed surface relative to the total volume and the segregation of particles during dumping.

Jan 1, 1966

By Donald Hulse

"Mining has been a source of controversy for at least 500 years. “Since there has always been the greatest disagreement amongst men concerning metals and mining, some praising, others utterly condemning them…” (Agricola, 1556). In 2016, it is widely recognized that mineral resources and reserves must give due regard to the social license in order to operate.“Most commonly, the social license to operate (SLO) is understood to refer to ‘the ongoing acceptance and approval of a [project] by local community members and other stakeholders that can affect its profitability’ (Moffat, 2014).” “Social License to Operate has gained traction, in part, because it is also a concept which – while remaining poorly, technically defined – is generally easily and widely understood by community stakeholders (Bice, 2014).”A generation ago we learned that mining is based on a stable platform supported by three pillars, geology, mining and metallurgy. The three-legged stool is a very stable structure (Fig. 1).In 2016, it seems that we have added some other legs to the stool (Fig 2). The Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC Code) addresses “social, and governmental factors…” (JORC 2012), and refers specifically to social license in Section 4 of the Report Template “Estimation and Reporting of Ore Reserves.”The Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Guidelines refer to “environmental, legal and social data…(CIM 2003).”Compared to these, the 2014 SME Guide is positively verbose stating “a discussion of any potential social or community related requirements and plans for the project and the status of any negotiations or agreements with local communities,” (SME 2014) although in all cases the scope of this disclosure is left at the discretion of the competent person.When there are more than three legs on the stool, it is imperative that all legs be constructed exactly to the design. Any one or more legs that are out of alignment will cause the stool to wobble.Engineers are trained to create designs to meet specifications. Loads can be estimated, forces calculated and cost studies completed that will lead to, not only a stable design, but the most efficient design that meets the specifications."

Jan 1, 2015

By McHenry Mosier

The Bureau of Mines, United States Department of the Interior, has established a testing adit on the Government reservation at Mount Weather, Virginia, to facilitate research on the fundamentals of mining under actual metal-mining conditions. A number of sites in several Eastern States were investigated, but Mount Weather was selected because the rock seemed best suited for rock drilling and other mining tests and because the ground was already owned by the Federal Government, the site having been acquired in 1902 for use of the Weather Bureau. The testing adit has an advantage over an active metal mine for certain investigations because variable conditions affecting any particular research problem can be controlled and maintained in a fixed status, whereas in an operating mine this seldom is feasible. Operations were begin in September 1936, with a crew of four laborers under a resident engineer. The laborers were recruited from nearby farms, and although they had no previous mining experience, they have developed into satisfactory miners.

Jan 1, 1939

By M Carr, K Williams, W Chen, J Plinke

The depletion of iron ore deposits at the face of the mine site dictates the necessity for the exploitation of formerly less attractive orebodies to meet the demand of the modern world. These orebodies will typically be found close to or even beneath the water table where an increasing clay and moisture content will result. Problematic iron ores, colloquially termed as ‘wet and sticky’ material (WSM), can have a significant impact in the material handling stream due to the expensive downtime of processing equipment, which is attributed to the inter-particle and boundary cohesion and adhesion forces of the bulk material.In order to gain a better understanding of the causes of poor handleability, experimental test methods to determine wall adhesion, and inter-particle adhesion within bulk materials were developed. Based on the combination of wall adhesion and inter-particle adhesion measurements, with traditional methods of assessing bulk material handleability, a new method to assess the potential of bulk materials to cause handling problems is proposed. This method reduces the multitude of factors leading to problematic behaviour to a handleability index (HI) [0,1], which is easily assessed and understood. The method is suitable for adhesive materials and applicable for a wide range of material flow, from gravity reclaim stockpiles to transfer chutes and carry back on conveyor belts.Additionally, this research presents an assessment of the HI derived by experimental testing of three iron ore samples. A clear understanding of the problematic behaviour of the iron ore samples is achieved with the use of dust extinction moisture (DEM) tests, which indicates the regions where problematic behaviour may be experienced on-site.CITATION:Carr, M, Plinke, J, Williams, K, Roberts, A and Chen, W, 2017. Determination of the handleability index of adhesive bulk materials, in Proceedings Iron Ore 2017, pp 503–510 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By M. M. Cole

An assessment of the combined application of remotely sensed satellite imagery, geobotany and biogeochemistry reveals the complementary value of these techniques in the Thalanga area. The SPOT imagery yields useful information on features of the terrain and discriminates the gossan over the ore zone. Geobotany differentiates geological units and the anomalous vegetation provides visual expression of the surface presence of the ore zone, while biogeochemistry effectively locates its concealed extension below Tertiary sediments and ferricrete

Jan 1, 1991

By J T. Woodcock, G J. Sparrow

A sample of pyrrhotite flotation concentrate pulp assaying 15.3 g/t Au, which had been prepared from an old tailing dump, was treated to extract the gold. Examination of the concentrate with an SEM showed that exposed or free native gold, 5- 40 ¦m in diameter, was present but no locked gold was observed. Direct cyanidation of the concentrate to extract the gold showed that the flotation reagents present inhibited gold extraction. A range of pre-treatments was used to overcome these effects. Direct cyanidation for 48 h extracted only 26 per cent of the gold, indicating possible contamination of the gold in the concentrate with flotation reagents. Pre-treatment of the concentrate pulp by aeration for 24 h, or by 72 h aeration with an addition of 3.65 kg/t of sodium sulphite, gave little improvement in gold extraction by subsequent cyanidation. Pre-treatment by filtration, or by aeration with 12.5 L/t 100 volume hydrogen peroxide, followed by cyanidation for 48 h gave gold extractions in the range 67-77 per cent. Combining filtration and an aeration period with hydrogen peroxide addition raised the subsequent cyanidation extraction of gold to 88 per cent, giving a tailing assaying 1.5 g/t Au. Re-cyanidation of some of the dried tailings from the initial tests extracted most of the remaining gold giving a tailing assaying 0.5 g/t Au. This indicated that most of the gold was available for dissolution by cyanide. The poor dissolution of gold by cyanidation of the untreated concentrate was attributed to the presence of flotation reagents. It was shown by UV spectrometry that xanthate-containing compounds were present in the solids fraction of the original pulp and that they were partly removed by pre-treatment. MIBC was also present, and dithiophosphate, which was used in the flotation step, was also probably present. The results indicated that the improvement in gold extraction after filtration and oxidation of the original pulp was due to partial removal of the flotation reagents, and illustrates the detrimental effects that residual flotation reagents can have on the extraction of gold by cyanidation of a flotation concentration.

Jan 1, 1990

Recent accelerated exploration efforts in southwest China have progressively quantified the vast phosphate resources in the Yunnan Province. To date, according to Chinese geologists, potential reserves in the province may be on the order of 4 Gt, which would equal the entire US reserve base. Development of this vast reserve is underway at two sites located 60-70 km southwest of Kunming, the provincial capital of Yunnan. The first, the Kunyang open-pit phosphate mine, produces an estimated 1.5 Mt/a of 22-30% P20,5. The other project located north of Kunyang is the Haikou mine, which the Chinese consider a possible 2.0-Mt/a operation. Because average ore grades run 3% less than those of Kunyang, beneficiation will be necessary. While the latter project has been initiated on a small scale, it is basically still on the drawing board. Brown and Root and the US Bureau of Mines are assisting on the project. Both operations are under the direction a regional administration which reports to the Ministry of Chemical Industries in Beijing. Combined production from both mines could represent some 70% of China's future productive capacity. Ore reserves in the region are estimated at 400 Mt by local officials. Geology of the District The phosphates are considered Cambrian in age and rest on a Precambrian dolomite. The Indian Ocean, Chinese geologists say, may have been the original source. The line of deposition stretches on a trend from Vietnam in the southwest, through Yunnan, into Sichuan Province to the northeast. Because the area is considered very stable from a geologic viewpoint, large quantities of phosphate have been deposited and large outcrops are known to occur everywhere in the province, according to Chinese sources. The Kunyang and Haikou ore bodies are thought to be two wings of an anticline with the former the southern portion, and the latter the northern portion. Each ore body strikes on an east-west axis. While there are many localized phosphate operations throughout the province, the Kunyang mine is the premium producer. Kunyang's Mining Development The Kunyang open-pit mine was opened in 1966. During the early years, operations were considered somewhat disorganized. Systematic mine planning and normal operations were not initiated until just two years ago, according to mine management. In 1979, Kunyang finally reached its design capacity of 1.5 Mt/a. The ore body consists of two phosphate beds separated by a band of shale. The top layer of phosphate varies from 4 to 8 m, averaging 6 m. The middle shale layer is 2 in. The third layer, which is not as rich as the top, is approximately 4 m. To further complicate matters, the ore dips 15° to the south over a strike length that is currently undefined, but believed to be

Jan 3, 1980

By Josee Boudreau

Transport Canada has regulatory requirements that pertain to the transportation of explosives. An important component includes the requirement for an approved Emergency Response Assistance Plan (ERAP). The ERAP may be traced to the recommendations made by Justice Grange following the enquiry into the Mississauga train derailment of December 1979. Justice Grange recommended that any shipper of dangerous goods must have a plan to control any release of dangerous goods in the event of an accident, and that the plan must be submitted to the Minister and approved by the Minister or by an organisation or person designated by the Minister. The right to ship could be withdrawn at any time if the plan is found inadequate either in its conception or in its operation.

Jan 1, 2010

By José Helio Sobrinho

O aço inoxidável austenítico alto nitrogênio ISO 5832-9 tem sido promissor na manufatura de próteses ortopédicas com resistência mecânica e de corrosão superiores a do aço tradicional ASTM F-138. Pesquisas recentes têm mostrado que esta liga apresenta resultados peculiares, tais como alta resistência mecânica, resistência à corrosão e presença de partículas de segunda fase (Fase Z) na matriz. Entretanto, não se sabe como se dá a correlação mecânica-microestrutural e de taxa de corrosão em regiões de processabilidade industrial desta liga na conformação a quente de peças. No presente trabalho, ensaios sob torção a quente isotérmico contínuo e interrompidos foram realizados após tratamento térmico de solubilização a 1.200oC, por 300 s com intervalos de temperatura variando entre 1.000°C e 1.200oC com taxa de deformação variando entre 0,05 e 5 s-1, para investigar a trabalhabilidade e a taxa de corrosão sob tensão desta liga com aplicação da técnica de espectroscopia de impedância eletroquímica e caracterização microestrutural, conduzida por microscopia óptica e varredura. Os resultados mostram que a tensão de escoamento é sensível aos parâmetros de deformação. O pico de tensão diminui com o aumento da temperatura e redução da taxa de deformação com alta taxa de recuperação dinâmica com grãos alongados, gerando regiões de acúmulo de tensão. Essas regiões de instabilidade plástica apresentam grau de corrosão superior em relação às amostras como-recebidas. As regiões de alta temperatura e baixa taxa de deformação apresentam boa trabalhabilidade com microestrutura final refinada com grãos recristalizados dinamicamente.

Aug 8, 2018

By A. R. T. Denues

Liquid oxygen explosives are ordinarily made from a carbonaceous absorbent and from liquid oxygen of high purity. These explosives have a limited but definite field of usefulness; their properties have been described in the literature, which includes several publications of the Bureau of Mines, the most recent dealing with fire-retardant treatments.3/ It seems generally conceded that the outstanding hazards in the use of these explosives are their high inflammability and their relative sensitivity to mechanical action. Each of these topics has been studied, and some interesting practical results have been obtained. Treatments have been described[7] that render liquid-oxygen explosives prepared from granular carbonaceous absorbents practically immune to the action of igniting agents representing or exceeding practical hazards in violence.

Jan 1, 1941