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By R. Ordóñez Olivares

This manuscript focuses on the design and development of steels for the railroad industry and methods of testing them. Here are summarized the results of research focusing on alloy development and design, with particular focus on advanced rails and wheels. The high-performance steels are characterized for their mechanical and service characteristics. The relationship between properties and cleanliness is discussed and compared to the regular railroad steel. Some of the tests presented are standard tests that are complemented with the nonstandard test recommended by the Association of American Railroads (AAR) and recommended modifications of this. The paper presents the results of metallurgical analysis, mechanical, and residual stress tests. The laboratory methods include microstructure, residual stresses, tensile, hardness, fracture toughness, and microcleanliness tests.

Jan 1, 2013

By Jie Deng, Wenliang Xiong, Binyan Chen

"With falling rare earth metal prices, low cost beneficiation of rare earth minerals is essential. The “Flotation-Agglomeration-Magnetic” (FAM) separation process is a newly developed technology by IMUMR to economically recover rare earth elements from different types of deposits. The theory of FAM process is to selectively agglomerate rare earth particles and separate from gangue minerals by bubble flotation process. The flotation product is further upgraded by magnetic separation. The FAM process has been successfully applied in industrial production on the Dalucao rare earth ore, Sichuan, China. The average REO grade of rare earth concentrate is 65% in the latest 12 month production run, with an average recovery of 55%.INTRODUCTIONRare earth elements (REEs) include fifteen lanthanide elements coupled with two chemically similar elements (yttrium and scandium). These elements are split into two sub-groups, La to Sm are classified as light rare earth elements (LREEs) and the remaining elements including yttrium are heavy rare earth elements (HREEs) (Kumari & Panda, 2015). The demand of rare earth elements surged in recent years due to their increasing usage in diverse industrial aspects including high strength magnets, phosphors, clean energy, polishing compounds and catalysts (Goley &Scott, 2014).More than 250 REE-bearing minerals have been discovered, but many minerals are with very low concentrations of REEs, varying from 10-300 ppm (Adam &Ping, 2013). The most common rare earth minerals mined are bastnaesite, monazite, xenotime and ion-adoption REE (Chelgani & Rudolph, 2015; Kanazawa & Kamitani, 2006). Before the 1960s, most rare earth resources were extracted from monazite in the beach placer, with the exploiting of Mountain Pass in the United States and Bayan Obo mine in China, bastnaesite became the chief mineral source of rare earth resources (Klinger, 2015). These minerals are commonly separated with gangue minerals by froth flotation, gravity concentration, magnetic separation, or any combination thereof based on their specific physical characteristics (Zhou & Wang, 2014; Adam & Richard, 2014; Yang & Satur, 2015; Xia & Brian, 2015a,b)."

Jan 1, 2016

By Jorge Madias

Se analizan las distintas alternativas para la producción de barras de refuerzo de hormigón: endurecimiento por solución sólida (“dureza natural”); endurecimiento por temple y autorevenido en línea (Tempcore, Thermex, etc.) y endurecimiento por precipitación (microaleación con niobio, vanadio o titanio) y su influencia sobre la performance de las barras, en lo que hace a la resistencia a la corrosión, al fuego y a los sismos.

Aug 17, 2017

By W. G. Freeman

This study provides recommendations for improved safety in underground blasting procedures based on in-mine observations of blasting practices in 30 underground metal, non-metal, and coal mines, and the analysis of blasting accidents since 1970 and existing state and federal regulations pertaining to the storage and use of explosives. Results of these analyses and observations indicate that 1) blasting accidents have declined but are an important contributor to the hazards of underground mining; 2) existing regulations are essentially adequate; 3) greater emphases should be placed on human errors and unsafe practices and the enforcement of existing regulations; and 4) future revisions of these regulations and standards should be organized, and their intent coordinated to eliminate ambiguities.

Jan 1, 1980

By Waldemar Lindgren

IN spite of a world production of lead amounting to 1,300,000 tons, of which the United States produces slightly less than one-half, it appears that the mines at present are hardly able to supply the demand. For this there are several reasons. The lead deposits, geologically speaking, were formed comparatively near the surface under conditions of lower temperatures, with the richer deposits often residuary; that is, enriched by surface water, and consequently soon exhausted. Lead is practically absent from a great part of the world. The great Canadian shield, the eastern part of the Dominion, contains practically none. Scandinavia contains no lead. It is absent from geo- logical formations of great age, but does occur in large quantities in the deposits in the Rocky Mountain region. These deposits are, more or less directly, of igneous origin, but here, too, there is a tendency of the lead shoots to concentrate in the upper part, and when they go down the deposits turn to zinc-copper and some other metals. This is one of the best established facts of economic geology. The deposits of the Mississippi Valley district, from Kansas-Oklahoma, to Canada, are in comparatively accessible limestone beds, at a depth seldom more than 500 ft. Therefore, the lead is easily mined but more easily exhausted.

Jan 1, 1926

By Rashid Bashir

The presence of groundwater in the form of large aquifers can have an important influence on investment decisions for underground mines. The design for such mines requires development of special mining methods, and mine dewatering infrastructure to avoid hazards during shaft sinking and underground development. The costs associated with mine drainage control and Mine Dewatering Systems (MDS) are relatively small compared to the huge consequential losses that can occur in case of an uncontrolled inflow and subsequent flooding of the mine. The design of MDS needs consideration of accurate prediction of the maximum uncontrolled inflow rate, availability of the system during an uncontrolled inflow while the inflow is mitigated, and decision on pumping system technology to have capability to operate under water. The research presented in this paper provides a theoretical framework for a reliability based design procedure which takes into account the uncertainty in the estimate of the maximum uncontrolled inflow, performance of the system during the period of an uncontrolled inflow and a methodology to decide on appropriate pumping technology considering the reliability of the system and available underground storage. The reliability based mine design procedure integrates the ideas of Effective Reserve and Hydraulic Reliability Index to come up with a unified methodology for design of Mine Dewatering Systems.

Aug 1, 2010

By B Murphy

Safescape Laddertube provides an improved system for emergency egress in ventilation shafts. The addition of Laddertube in a rise has very little impact on ventilation flow, studies have indicated that the difference in flow velocities are difficult to measure due to the minimal impact. Due to the size and open-ended nature of Laddertube, the air velocity inside and out of the Laddertube is mostly linear. Laddertube can be used either permanently or during an emergency as a secondary ventilation duct. One project involved a 385 m ladder installed in a surface return air raise that could be made to bypass the primary circuit and supply fresh air to a sea container fresh air base at the bottom of the raise. Laddertube has been designed to be installed to any feasible length and can be fitted with a climb assist system ensuring enhanced speed and reduced fatigue during ascent. The climb assist used in association with Laddertube is a Tractelift system which applies a weight relief of up to 36 kg off the climber’s body weight when using the ladder. This system has successfully been tested for ladders up to 600 m in length and is currently in use for a ladder of 185 m length. The use of refuge chambers in underground coalmines has long been a contentious issue due to the concern that while it may provide temporary shelter, the risk of being exposed to high heat or the inability for rescuers to access them due to fire or explosive atmosphere means that they may be effectively trapped. The additional application for coal environments includes Laddertube installed alongside a refuge chamber concealed behind a blast proof door ensuring a secondary means of emergency egress. In certain operations designs may allow for this chamber to be provided withpositive pressure fresh air.

Oct 12, 2022

By Matheus Felipe dos Santos, Eric Yoshimitsu Sako, Murilo Henrique Moreira, Douglas Fernando Galesi, Ricardo Afonso Angelico, Vladnilson Peter de Souza Ramos, Maria Gabriela Garcia Campos, Victor Carlos Pandolfelli

O consumo de energia em panelas de aço está relacionado às etapas do processamento que ocorrem durante o refino secundário. O aço líquido perde energia térmica quando são adicionadas ligas, pelo sopro de gases, agitação e por convecção natural. Cerca de 70% dessas perdas ocorrem pelos revestimentos refratários, que dissipam energia para o ambiente quando suas superfícies são resfriadas. A microestrutura dos refratários Carbonfree resulta na redução da transferência de calor no material, devido a presença de fases de baixa condutividade térmica (por exemplo, agregados porosos) e sem o carbono que é uma fase usualmente presente e aumenta a condutividade térmica nos materiais. O processo nas panelas de aço é transiente e necessita de ferramentas numéricas avançadas para investigar o desempenho desses materiais nas condições específicas de cada aciaria. Tais ferramentas foram aplicadas para estimar o potencial de conservação de energia dos revestimentos Carbonfree em um caso real (linha de metal e sola) e os resultados mostram um potencial de redução de 21%. Os testes realizados in-situ compararam as diferentes taxas de queda de temperatura para cada configuração com as previstas pela ferramenta. Os benefícios estimados foram comprovados e a eficiência dos materiais investigados foi validada.

Oct 1, 2019

By Brad Wahlquist

An ex-situ biological treatment system was implemented at a gold mine site in South Dakota. The system removes selenium and nitrate from a mixture of groundwater and surface water runoff at ambient water temperatures. The Applied Biosciences? system replaced a denitrification system that did not perform consistently, did not treat for selenium and required heating of the influent water. Installation was completed in phases starting with the selenium circuit being brought into operation in February, 2002 and the nitrate circuit in March, 2002. System design can accommodate average flows of 380 L/min (100 gallons/minute) and a maximum flow of 1,136 L/min (300 gallons/min). Four cells were designed to remove nitrate from approximately 30 mg/L to below 10 mg/L and two cells were designed to remove selenium from 0.01 mg/L and higher, to below 0.005 mg/L. No pretreatment is required to operate the system at ambient temperatures, which can fall as low as -12C in the winter, and treat water at temperatures ranging between 8C to 16C. Nutrient requirements are met using a sugar based nutrient mixture that includes a balanced C:N:P:S ratio, trace elements and vitamins. Since start up, the system has consistently been in compliance for nitrate and selenium, treating water to below detection limits for both contaminants. This paper discusses laboratory biotreatability testing of a system designed to remove selenium, arsenic, and nitrate and full-scale implementation and optimization of a system to remove nitrate and selenium.

Jan 1, 2003

By J. Koster

[In lQ jG thc E'lcct,ro:~(: L7.l :~u..-ic:ll S;%cti ?n of t?c :I. tcIl~tr,-;lcal 3:vi cioa, ?U~CE~U of lv!irtos, bc,~m an 9.ct iv.t In-:?*t ik7;5i GI of r.:ct.l-;c?;is for rccovcrin,; niclrel, cop?ir, an2 ?? cciou:; ~ot-1 c 1;-on or; :; of tile 3unl~crvi~.l~~ tiistrict in C1ni.k Coult:r, !Icl.r. ]

Jan 1, 1939

By C. M. McCulloch

The methane content of virgin bituminous coalbed can now be measured accurately in the field with exploration core samples from vertical boreholes. The gas content of the coal per unit weight can be used either to design a mine ventilation system or to determine if degasification of the coalbed will be necessary before mining, and to determine the gas resources in the coalbed. The equipment necessary to conduct the test costs less than $50. The gas con-tent of the coal in place in the ground is determined by summing the gas lost from coring, gas measured during desorption, and the residual gas in the coal. Upon removal from the borehole, the core sample is placed in an airtight container and des orbed for several weeks until the desorption rate is below 0.05 cm3/g for 5 consecutive days. The gas lost from the core while it was being cored and the residual gas are estimated by a new graphical method. The amount of gas remaining depends upon whether the coal is friable or blocky. Friability appears to relate to the depth of the sample below the surface, fixed carbon percentage, Hardgrove grindability index, and proximity to tectonic disturbance. Friable coals emit nearly 96 pct of the total gas during desorption whereas a blocky coal emits only 60 pct of its total gas. Coalbeds that are ill defined as to their blocky or friable nature must be tested in the laboratory for unambiguous analysis.

Jan 1, 1975

By Kai Zhang, Aijun Huang, Jeremy H. Rao, Xinhua Wu, Paul Rometsch

"As one of the most typical additive manufacturing (AM) technologies, selective laser melting (SLM) removes many of the shape restrictions that limit materials design, thereby allowing computationally optimised and high performance structures to be directly produced and tested. Due to the high reflectivity and lower absorptivity of Al alloy A357 powder during high temperature laser melting, one of the issues SLM might bring is the surface roughness and defects present on the parts. In this regard, this study investigates the surface roughness – fatigue property relationship for a heat-treated aluminium alloy A357 after SLM. Via the adjustment of SLM parameters, an ultrafine microstructure can be obtained due to the fast solidification rate. Therefore, comparable or even better mechanical properties can be achieved with respect to traditional A357 casting counterparts. Meanwhile, the surface roughness conditions of the SLMed Al alloy are also influenced by various processing parameters, raw powder properties, and sample building methods. For selective laser melted Al alloy A357 specimens, a dense part with a smoother surface would be expected to correspond with a good fatigue performance.INTRODUCTION Additive Manufacturing (AM), also known as 3D printing, is a process in which a complex part is fabricated layer by layer from a digital design package (Martin et al., 2017). AM has the potential to conserve raw materials, reduce the energy consumption, part cost, and fabrication time. Furthermore, as a typical additive manufacturing (AM) process, selective laser melting (SLM) was originally developed from selective laser sintering (SLS) based on higher quality lasers (Rao, Zhang, Fang, Chen, Wu, & Davies, 2017b). Different from conventional casting consuming valuable time and energy, SLM is now used as a cost effective method for the manufacturing of metals, such as Al-Si alloys, to produce almost full density parts using fine metallic powder and high power laser beam (Tang & Pistorius, 2017)."

Jan 1, 2018

By O. Dojcar

Equations for calculating the parameters of controlled blasting (burden and spacing of boreholes and weight of the bottom charge) are derived and analysed on the basis of empirical values and made more precise through incorporation of the properties of the rock being blasted and explosive applied. For the success of controlled blasting the correct choice of the blasthole diameter/charge diameter ratio is critical. This relation is defined as the coefficient of radial decoupling of the charge; it is recommended that it is chosen to be between 3 and 3.5. Analysis of smooth blasting, cushion blasting and presplitting indicates that cushion blasting is a less destructive alternative to smooth blasting, but it has a slightly higher blasthole consumption and limited possibilities of use. There are definite economic advantages to controlled blasting, especially in rock masses of low and medium strength

Dec 1, 1996

By Guanghua Ai, Xiong Huang, Huashan Yan, Ting Li, Tingsheng Qiu

"Cyanide tailings of gold and silver concentrates contain considerable quantities of copper-lead-zinc sulfide minerals that can be recovered. However, the strong inhibition effect of cyanide often makes it difficult to recover these sulfide minerals effectively. In this research, a sample of cyanide tailings was investigated based on the principles of process mineralogy; activating flotation tests were carried out for the target minerals in the tailings, and the activation mechanism of the activator and its influence on the target minerals were investigated by Fourier transform infrared spectroscopy (FTIR). Mixed flotation of copper and zinc was carried out using QJ-01, a combined agent containing sulfite, as the activator of copper and zinc minerals, and ammonium dibutyl dithiophosphate (ADD) and butyl xanthate (BX) as the combined collector. Copper concentrate was obtained from the mixed concentrate by using a combined inhibitor of sodium sulfide and zinc sulfate to inhibit the zinc mineral. Zinc concentrate was extracted from the copper tailings by using copper sulfate as the activator and BX as the collector. The flotation test yielded copper concentrate with a grade of 22.56% and recovery of 76.96%, and zinc concentrate with a grade of 42.56% and recovery of 82.29%, which shows that comprehensive recovery of the sulfide minerals – copper and zinc –from the cyanide tailings was realized. The FTIR analysis showed that CN- was chemisorbed on the surface of chalcopyrite and sphalerite following cyanide treatment, while the combined activator QJ-01 containing sulfite reduced CN- into SCN- and weakened the complexing ability of CN- with metal ions on the mineral surface, thus achieving a good activation effect on chalcopyrite and sphalerite. The results of this study can provide practical guidance in increasing the resource utilization ratio of cyanide tailings in gold mines, and thus contribute to alleviating environmental problems caused by stockpiling cyanide tailings. INTRODUCTION Cyanidation, the most widely used technology for extraction of gold, has several advantages such as high recovery, process maturity, low cost, etc. According to available data, the annual discharge of cyanide tailings from China's gold mines exceeds 20 million tons (Li et al., 2011). Lower grades of exploitable gold ore entail increased discharge of cyanide tailings. Huge quantities of cyanide tailings are regarded as waste and stored, resulting in significant wastage of land resources. Moreover, residual beneficiation reagents, cyanide ions, and heavy metal ions in cyanide tailings cause severe pollution of water and land (Laitos et al., 2013; Donato et al., 2007; Mudder and Botz, 2004). In addition, cyanide tailings often contain valuable elements such as gold, silver, copper, lead, zinc, sulfur, and iron, which, if not recycled, would result in considerable wastage of resources. Hence, it is imperative to study the reduction and safety of cyanide tailings, and the mineral resources present in them."

Jan 1, 2018

By J. D. Vincent

The Henderson mine site is located at Red Mountain on the eastern slope of the Rocky Mountains, approximately 50 miles west of Denver, Colorado. The mill site is on the west slope of the Rockies and mine and mill will be connected by an underground railroad. All designs were for a 30,000 ton per day molybdenite processing plant with provisions for future expansion up to 50,000 ton per day if required. This plan did not just happen, but slowly evolved over the course of about three and one-half years. Many plants cannot afford such a delay, but the Henderson project will take about 10 years from the time it was first discovered until production starts, and these 3 !1 years were well spent in determining the best possible plant site and flowsheet. This paper describes some of the problems and the decisions made in arriving at the final location and flowsheet. The paper does not go into the specific details of how protection of the environment went hand-in-hand with all other project considerations. This particular aspect of the planning has been well-reported on other occasions and considerable information on it is readily available.

Jan 1, 1972

By Maurice E. Bailey

The purpose of this study is to determine worker acceptance of modified mine equipment at various intervals during a twelve month period. A survey instrument was administered to the workers by two experienced miners in four interviews. All four interviews showed a significant positive response to all modifications, except the small size of the cab of the shuttle car; however, the small size produced significant negative responses with respect to comfort in each of the four interviews. Initially, (interviews one and two), there were significant negative responses with respect to manufacturer receptivity to operator suggestions and program management follow-through on operator suggestions; however, the third and fourth interviews showed no significant negative responses with respect to these items. Likewise, there were significant neutral responses in the first two interviews; however, the third and fourth interviews showed no significant neutral responses with respect to these items.

Jan 1, 1975

By Jinung Do, Sung-Ryul Kim, Juhyung Lee

"Model tests have been performed to investigate the vertical, horizontal and cone tip resistances of bucket pile embedded in sand by different installation methods; suction force by pump and jacking force by actuator. Micro-cone penetrometer is used to evaluate the variation of the effective stress inside and outside of the pile after installation. As a result of vertical pull-out test, the jacked pile shows 3 times larger resistance than the suction-installed pile. For horizontal pull-out test, the ultimate horizontal capacity and the slope of load-displacement curve on the suction-installed pile decreases by 22% and 40%, respectively, compared to the jacked pile. In cone penetration test, inside cone tip resistance of the suction-installed pile is about 40% smaller than the jacked pile, which indicates that the effective stress is reduced due to upward seepage of bucket pile in sand by suction force. Therefore, installation methods can affect the behavior of the bucket pile significantly.INTRODUCTIONA suction force occurred when bucket pile penetrates into sandy soils induces seepage flow into the bucket pile so downward seepage near the outside of bucket pile causes to increases the effective stress, while upward seepage inside the bucket pile decreases the effective stress (Mahn, 2005; Fig. 1). The effect of induced seepage causes to reduce the penetration resistance during installation. On the other hand, reduced effective stress can decrease the horizontal and vertical capacities of bucket pile by significant disturbance at the tip of the bucket pile due to the flow net. Due to the complexity and difficulty considering the effects of suction installation, many previous researchers generally have neglected the effect of suction installation in their experiments. Therefore in this study, the effects of suction installation on resistance of bucket pile is examined."

Jan 1, 2016

By J. J. Denny

The purpose of this paper is to present, briefly, an outline of Canadian practice in the milling of gold-bearing ores- not, however, including those auriferous ores which are mined and milled primarily for their content of some other metal. It is not the writer's intention to offer technical data, nor to discuss any particular phase of the metallurgy, but rather to give a general résumé of past and present methods. As it is only within recent years that gold milling has assumed prominence in Canada, much of the technology is modern, and detailed articles describing the practice adopted in the several mining districts, and recording the various changes and innovations that have been made from time to time, are to be found in the Transactions of the Canadian Institute of Mining and Metallurgy, and in the mining journals. Prior to the year 1860, any gold that had been produced in Canada had come from placer operations in British Columbia, but ' during that year lode gold was discovered in Nova Scotia, in quartz veins, and in several localities mines were opened and small mills of very simple character were erected to treat the ore. These plants, equipped with stamps, or arrastre, were only effective in recovering the free gold. Concentration and chlorination were introduced in an endeavour to save the gold occurring in intimate association with metallic minerals, but, due to various circumstances, gold mining and milling did not progress in Nova Scotia.

Jan 1, 1930

By J. K. Kerver, J. S. Osoba, J. G. Richardson, J. A. Hafford

A detailed study of a number of methods of relative permea-abilitv measurement has been made in a search for the tech-niqrle most suited to routine analysis of cores taken from reservoir rock. It has been found from tests run on the same samples of core material by a number of techniques that the Penn State, Hassler, Hafford, and dispersed feed techniques all yield results which are felt to be reliable. Conditions under which the faster single core dynamic technique may be used are described. Further work on the calculation of relative permeabilities to oil from data obtained by the gas drive method is needed before this latter rapid method can be utilized. Correlations between theoretical studies and experimental results have been obtained in studies of the boundary effect. pressure distribution in two-phase flow, and gas expansion effects. Previous conclusions that the effects of the outflow boundary could be made negligibly small have been substantiated. Results of experimentally determined oil and gas pressure distributions along a core sample during flow are presented. Further studies of the effects of rate of flow in the measurement of relative permeability-saturation relations have shown that results are independent of the rate of flow as long as the flow rate is below the point where inertial effects commence. An analysis of the effects of a severalfold expansion of gas along the flow path indicates that while saturation gradients are induced in the test sample, the errors caused by this phenomenon in relative permeability measurements are small. INTRODUCTION Many pages of literature have been devoted to pointing out the need for relative permeability-saturation relations in reservoir engineering. One of the most attractive ways of obtaining this information is by the analysis of samples of core material taken from the formation in question, and again literature has described man); methods for obtaining these data. It is the purpose of this paper to present the work that has been done in the study of some of these published methods together with some other methods that have been recently developed in this laboratory. Also, a study of some of the factors that influence the laburatory determination of relative permeability-saturation relations is presented. FACTORS WHICH AFFECT LABORATORY STUDY OF FLUID FLOW THROUGH RESERVOIR ROCK To determine relative permeability-saturation relations of samples of reservoir rock in the laboratory, it is important to know what factors affect these measurements in order that the magnitude of these effects can be ascertained and steps then can be taken to eliminate or, in some cases, to minimize them. The factors that have been investigated are the boundary effect, the effect of gas expansion. and the rate effect. Boundary Effect In laboratory experiments in which two immiscible fluids are flowed through a porous medium, there exists a discontinuity of capillary properties at the outflow face. This discontinuity exists became the fluids pass from a region of finite capillary pressure in the sample to a region of zero capillary pressure in an open receiving vessel. The capillary forces existing in the core caupe the rock to tend to retain

Jan 1, 1952

By G Mudd, N Haque, S A. Northey

Life cycle assessment (LCA) provides an internationally standardised framework for estimating the environmental impacts associated with products or services (International Organisation for Standardisation, 2006). A particular strength of LCA is the ability to consider indirect impacts that occur at different stages of a product’s life (eg raw material acquisition, manufacture, use, disposal or recycling) and through its supply chain (Figure 1). A wide variety of impact categories are able to be considered by LCA, such as the potential contribution to global warming, ozone depletion, marine eco-toxicity or freshwater eutrophication.CSIRO has a long history of using LCA to compare the environmental impacts associated with alternative mining, mineral processing and metal production technologies (Haque and Norgate, 2014; Norgate and Haque, 2012, 2013). These ‘mine-to-metal’ assessments have primarily focused upon estimating embodied energy and greenhouse gas impacts associated with these production processes; however, more recently there has been a refocus to also consider consumptive water-use impacts in more detail (Northey et al, 2014).CITATION:Northey, S A, Haque, N and Mudd, G, 2016. Water-related data requirements for improved life cycle assessment of mining, mineral processing and tailings management, in Proceedings Life-of-Mine 2016 Conference, pp 16–18 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016