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By K. Awuah-Offei, A. U. Rehman

"Information diffusion potential of a social media user affects how quickly information about a mineral project can diffuse through that user. If management can use social media and network analysis, in community engagement program, to understand how fast and how far information will diffuse to communities and followers of particular social media users, it can selectively focus on the most influential users. This paper proposes a method to examine the information diffusion potential of social media accounts. The work uses Gephi, an open source software, to extract and analyze data from different Twitter handles to predict their information diffusion potential. The work uses case studies of real Twitter users (e.g. mining news organizations and bloggers) associated with mining to illustrate the approach. The case study results show that there are significant disparities in information diffusion potential that will demand selective attention. This research will help mines develop effective social media engagement strategies. INTRODUCTION The mineral industry provides raw material for industrial activity to support our society (Martens and Rattmann, 2001). Mines have changed conventional mining practices to sustainable ones because of the negative impacts of mining and increased public awareness (Wang et al 2016). The concept of sustainable mining is getting mature as stakeholders (e.g., governments, investors and host communities) are getting involved in mining projects (World Economic Forum, 2014). The failure of mining companies to address the demands of these stakeholders might result in failure to acquire social license to operate (Thomson and Boutilier, 2011). The social license to operate (SLO), if granted, is mutually beneficial to all stakeholders. Mines prefer being granted SLO and keeping it to avoid any kind of social unrest due to their operation (Prno, 2013; Moffat and Zhang, 2014). Mining communities can grant different levels of SLO; ranging from withholding SLO to psychologically identifying with the project (Joyce and Thomson, 2000; Thomsan and Boutilier, 2011). Most of the previous work to understand community perceptions and SLO in mining is generally qualitative (ICMM, 2012a; Thomson and Boutilier, 2011; Prno, 2013; Moffat and Zhang, 2014; IFC, 2014). In particular, there is limited work on how community perceptions change over time due to information diffusion (Boateng and Awuah-Offei, 2017). However, SLO changes with respect to time (Yates and Horvath, 2013), which can result in risks that are not easy to predict. Mine managers and engineers have a desire to understand these changes so as to mitigate these risks (Que and Awuah-Offei, 2014; Que et al., 2015)."

Jan 1, 2018

By Leandro Mendes Pinto

Este artigo apresenta um estudo de analise da viabilidade da substituição de 1 motor padrão utilizado em uma torre de resfriamento por 1 motor de alto rendimento Premium acionado por um Inversor de frequência interligado ao controlador de temperatura. Nas Torres de Resfriamento, ao implantar uma solução que pode a variar a velocidade dos ventiladores de acordo com a temperatura ambiente e a exigência de resfriamento do processo, pode-se obter grandes ganhos em economia de energia. Neste cenário, os motores elétricos têm papel determinante pelo amplo uso na indústria devido a sua versatilidade e eficácia. Por isso, melhorias e inovações são sempre necessárias para otimizar processos e aumentar a lucratividade.

Sep 25, 2017

By Robert D. Brown

"On April 22, 1980, the Ontario government introduced a totally new incentive program for mineral exploration in the province to be effective September I, 1980. Replacing the former Mineral Exploration Assistance Program (MEAP) and also the assistance formerly provided to the mining sector under the Small Business Development Corporations Act, the new Ontario Mineral Exploration Program (OMEP) promises to offer a valuable benefit to certain eligible applicants.Unfortunately, the program is not without its shortcomings: the eligibility for grants or tax credits under the program is comparatively restrictive, and an October 1980 federal budget provision to amend income tax legislation would blunt some of the originally intended attractiveness of the grants and credits.IntroductionIn his budget of April 22, 1980, Ontario Treasurer Frank Miller introduced a new incentive program to encourage mineral exploration in the province.The Ontario Mineral Exploration Program (OMEP) replaces the Mineral Exploration Assistance Program (MEAP), which will be phased out by March 31, 1981. Exploration programs approved under MEAP will continue to qualify for incentives under that program, but will not qualify for OMEP."

Jan 1, 1981

By A. E. J. Gallagher

There are many influences which have a bearing on the economics of industrial minerals production. The purpose of this paper is to discuss briefly three factors which have economic significance in the production of these mineral commodities. The three items of discussion include 1) the nature and relative value of the industrial minerals group, 2) project planning, and 3) market analyses. General aspects of these factors are familiar to most of us. However, an attempt will be made to give some current details regarding each. Also, in reality, project planning and market studies are usually so closely associated that they will be discussed jointly, rather than separately. This will be done by way of examples which show how these two activities actually evolved for two industrial minerals projects.

Jan 1, 1984

By J. F. Wright

During the last three years prospecting has been active in southeastern Manitoba and a number of interesting gold, nickel and copper deposits have been discovered within an area 90 miles north of the international boundary, and extending about 40 miles westerly from between mileage 60 and 110 on the Manitoba-Ontario boundary. As known at present, two-thirds of this area of 2,000 square miles is underlain by pre Cambrian granite and granite gneiss and is not likely to contain mineral deposits of economic importance. The remaining one-third is underlain by metamorphosed sediments and lavas (greenstones), penetrated by the granite and granite gneiss and, at various localities, cut by bosses, sills, or dykes of gabbro, diorite, granodiorite, and other types of intrusives. The nickel, copper, and gold mineralization accompanied or followed the intrusion of these different rock types. The gold deposits are limited in distribution, so far as known, to the northern part of this prospecting area and occur along Manigotagan and Wanipigow rivers. These deposits have recently been described in some detail, (3) and therefore only the copper and copper-nickel deposits of the southern part of this area, along Oiseau and Maskwa rivers, will be described in this paper.

Jan 1, 1925

By Elmer A. Peña M

Dado que la concentración de sulfuros de fierro: pirita y pirrotita aplicados gravimétricamente en espirales Humphreys obtuvo resultados óptimos tanto en lo económico como en lo metalúrgico, surge la necesidad de construir una planta concentradora de sulfuros de hierro en la Cerro de Pasco Corporation utilizando como cabeza los relaves de la planta de flotación de minerales de cobre. En este sentido, el objetivo del texto describe el proceso de dicha concentración, donde señala que la alimentación a la nueva planta es una pulpa que requiere mantenimiento de supervisión y mantenimiento, generando un concentrado de fierro a un costo de s/.6. 00 T. C. S. contra s/. 105. 00 T. C. S.; costo del concentrado de fierro producido por flotación en 1961. Asimismo, las diferencias de gravedad específica entre sulfuros de fierro y ganga cuarcífera han ido aprovechados para lograr un ejemplo donde la concentración gravimétrica, actúa con éxito frente al actualmente difundido proceso de concentración por flotación.

Aug 20, 1963

By Jim Wickens, Andy Cole, John Pekrul

"The roaster facility at Barrick Goldstrike Mine treats double-refractory sulfidic/carbonaceous gold ore. Prior to oxidation in the roasters, the ore is ground in two parallel dry grinding circuits utilizing 19’ Ø x 75’ double rotator mills. The design plant throughput was 12,000 dstpd. However, process improvements have significantly increased throughput rates by 25-50%. The current daily throughput record is 20,078 dstpd. Grinding circuit improvements contributing to this success include feed size reduction, ball size optimization, automatic ball charging optimization, and operating strategy changes. In addition to the changes already made, this paper discusses future optimization initiatives including on-stream particle size analysis and “real-time” ore hardness determination techniques.INTRODUCTIONBarrick Goldstrike Mines is located 29 miles Northeast of Carlin, Nevada, USA. Through 2001, the property has produced over 23 million ounces of gold making it one of the premier gold operations in the world.Prior to Barrick’s ownership, the property began producing gold from a small heap leach operation in 1975. The small-scale heap leach production continued through 1986, and in January 1987, Barrick acquired the property. Increased exploration activity by Barrick significantly increased gold reserves. In August 1988, a 4,500 dstpd mill facility was commissioned to treat high grade oxide ore. Also, heap leach operations had significantly expanded. In 1990, the mill was expanded to 6,000 dstpd, and the first autoclave was commissioned to treat refractory sulfide ore. By the end of 1996, the mill and pressure oxidation facility had expanded to 16,000 dstpd and heap leaching had ceased as oxide reserves were exhausted. In 2000, a roaster facility was commissioned to treat double-refractory sulfidic/carbonaceous ore."

Jan 1, 2003

By Reno M. Pappas, Christopher Mark

This report presents results of a U.S. Bureau of Mines study of longwall gob material. The objective of this work was to determine material stiffness properties of the gob for use in numerical models of rock mass response to longwall mining. Photographs of actual mine gob were digitized to obtain approximate particle size gradations of gob material. The gradation curve was shifted down to a lab- oratory scale, and 20 uniaxial compression tests were conducted. Varying the maximum particle size was not found to affect the stress-strain behavior, but changing the gradation appeared to influence the stress-strain behavior. The stress-strain relationship of the simulated gob material was nonlinear, the stress-secant-modulus relationship, was approximately linear, and the stress-tangent-modulus relationship was approximately a second-order polynomial function. Equations were generated from these curves, providing numerical modelers with a means to estimate gob moduli based on the stress level. In addition, the experimental data were statistically evaluated using multiple regression analyses, producing a series of equations to predict the secant and tangent moduli from the given stress level, bulking factor, rock strength, and thickness-to-width shape ratio of the particles.

Jan 1, 1993

By R. N. Chakravorty

Environmental monitoring plays a key role in coal mine safety. In recent years, significant advances have been made in the development of systems suitable for monitoring air in underground coal mines. Because of intensive mining and large capital outlay, the need for higher productivity consistent with safety is well recognized and it appears that environmental monitoring may help achieve this objective. This paper reviews the state-of- the-art in the monitoring technology with particular reference to hazardous gas detection in underground coal mines. The preliminary results obtained from ongoing studies, with regard to continuous monitoring of methane and carbon monoxide in mine air in some of the operations in Western Canada, are discussed. The inadequacies of the methods using spot samples are examined and the need to supplement the present practice with continuous monitoring systems is emphasized.

Jan 1, 1979

By Alessandra Vieira Guimarães

A liga de Níquel 718 é bastante requisitada para aplicações na indústria aeroespacial devido as suas excelentes propriedades. Endurecida por precipitação, a liga apresenta alta resistência mecânica sob condições extremas e ambientes severos, representando um avanço tecnológico significativo na produção de motores aeroespaciais. Os reparos realizados nos motores são feitos por diferentes processos, porém muitas vezes são realizados até que as especificações estruturais deixem de ser atendidas. Após os reparos, a liga é solubilizada em temperatura inferior a temperatura solvus da fase d, o que pode levar a precipitação crescente desta fase, podendo impactar nas propriedades da liga. O intuito do presente trabalho é avaliar o efeito de múltiplos ciclos de tratamentos térmicos de solubilização e envelhecimento na microestrutura e propriedades mecânicas da liga. Foi possível observar que os múltiplos ciclos induzem uma crescente formação de fase d, reduzindo a resistência mecânica da liga.

Oct 30, 2017

By T. W. Smelser

This Bureau of Mines report presents a review of underground testing, test results, and design guidelines of steel-fiber-reinforced concrete (SFC) mine support (cribbing) developed at the Spokane Research Center. The objective of the work was to verify, in field applications, the performance, economics, and acceptance by the mining industry of the SFC supports and establish design guidelines for their use underground. Results indicate superior performance, favorable economics, and enthusiastic acceptance by the mining industry.

Jan 1, 1983

By J. A. Kosek

Work has been carried out under Bureau of Mines Contract HO 395132 to develop improved sensor cells for use in direct-reading detectors and diffusion exposure meters. A pumped CO sensor cell was developed which has a shorter response time, improved temperature cycle characteristics, and improved linearity and stability at high CO concentrations. Diffusion CO sensor cells have shown good response level stability and linearity up to 1000 ppm. In addition, a new sensor cell catalyst has been developed for NO2 sensor cells which has a much shorter response time and improved response stability characteristics.

Jan 1, 1982

By M. R. Leonard

It is estimated that between 5 and 15 pounds of solid waste are generated monthly by each individual. Finding a final resting spot for such waste is an important matter. In the "good ole days," dumps of every description and condition were available. Not so now. Almost all states have adopted and are enforcing strict regulations regarding the disposition of solid waste. Many companies, owing to the nature of their business, have potentially good waste-disposal sites available. Cleveland Quarries Company falls in this group; but in spite of our having state and county permits, opposition by the local community denied us the opportunity to provide a needed local service.

Jan 1, 1974

The Department of Mineral Resources is the lead agency in mine site environment management and control inNew South Wales. The Department introduced a Mining, Rehabilitation and Environmental Management Plan (MREMP) process several years ago in order to integrate the activities of other government agencies who may have a material interest at the mine site. The MREMP process has resulted in a spirit of trust and co-operation between agencies and between agencies and mining companies. The spirit of co-operation has been reflected in greater public confidence that mining is environmentally responsible.  

Jan 1, 1995

By Omid Marzoughi

Chromium has a wide range of applications, including as an alloy addition in various steels and also as a corrosion resistance coating. Carbothermal reduction of chromite ore (FeCr2O4) in a submerged arc furnace is an important industrial process for extracting chromium, but the energy consumption is excessive. It is suggested that one area for future research is the low temperature carbothermic solid state reduction of chromite to produce an intermediate product, which can subsequently be upgraded to ferrochromium. In this regard, a thermodynamic model has been developed to investigate this process and the effects of temperature, carbon additions and ore composition on the recovery of chromium and the grade of the ferrochromium, have been studied. Further development of the model may allow it to be applied to the simulation of other processes for the recovery of chromium from chromite ores.

A comprehensive review of ore pass records, from ten Quebec underground mines, indicated some of the limitations of available design tools to predict the occurrence of ore pass interlocking hang-ups in metal mines. The Distinct Element Method was used to perform a series of numerical experiments in order to investigate the influence of ore pass geometry, rock fragments shape and size distribution on material flow in an ore pass. Guidelines have been developed to help limit the occurrence of interlocking hang-ups in an ore pass. The proposed guidelines were evaluated with respect to field observations. Ein kompletter Bericht der Erzrollezeichnungen, von 10 Quebec unterirdischen Gruben, hat einige der Beschränkungen der vorhandenen Designwerkzeuge angezeigt, um das Auftreten Erzrolle der blockierenhang-ups in den Metallgruben genau vorauszusagen. Eine Reihe numerische Experimente mit der eindeutigen Element-Methode, wurden aufgenommen, um den Einfluss von Erzrollegeometrie, Partikelform nachzuforschen und Felsenkorngrößenverteilungen auf Materialfluss in ein Erz überschreiten. Dieses hat zu die Entwicklung der Richtlinien geführt deren Implementierung das Auftreten der blockierenhang-ups in eine Erzrolle begrenzen sollte. Die vorgeschlagenen Richtlinien wurden in Bezug auf Labor- und Feldbeobachtungen ausgewertet. Une revue de la performance actuelle des cheminées à minerai dans 10 mines souterraines du Québec a indiqué les limites des outils de conception servant à dimensionner les cheminées pour minimiser le nombre d’accrochages par enchevêtrement rocheux. Des séries de modélisations numériques, utilisant la méthode des éléments distincts, ont été réalisées afin d’évaluer l’influence de la géométrie des cheminées, de la forme des fragments rocheux et de la distribution granulométrique sur l’écoulement du matériel dans les cheminées. Cet exercice a permis de développer des lignes directrices pour le dimensionnement des cheminées afin de limiter l’occurrence d’accrochage par enchevêtrement rocheux. Les lignes directrices proposées ont été évaluées en fonction des observations effectuées sur le terrain.

Jan 1, 2003

A massive cobalt-containing pyrite orebody occurs in banded albite-quartz-biotite rocks at Thackaringa, some 30 km SW of Broken Hill. Because of the world-wide shortage of cobalt during the late 1970s, serious consideration was given to the development of a suitable flow-sheet to recover the cobalt from this ore. Details of a pressure leaching process in which more than 90 per cent of the cobalt is extracted from a pyrite concentrate are presented.

Jan 1, 1983

By Mitchell L. Fong

The Bay Area Rapid Transit (BART) District will be extending BART service south along an 8.7-km (5.4-mile) -long corridor in the city of Fremont, California as part of the Warm Springs Extension (WSX). The WSX project will link the existing BART system to the future BART to San Jose extension. A segment of WSX is located in Fremont Central Park (referred to as the Fremont Central Park Subway Project). The Fremont Central Park Subway is considered the most complicated and geotechnically challenging portion of the project with an underground subway box being constructed near the active Hayward Fault which is capable of ground motions up to 0.75 g and is located in an aquifer which is used for water storage and supply. Soil-structure interaction analysis was used in the design of the subway box to resist deformations due to earthquake ground motions. A water-tight excavation support system has been designed to allow subway box construction while minimizing impacts to the aquifer.

By Charles Will Wright

The purpose of this paper is to present briefly certain preliminary results of the study of mining methods by the United States Bureau of Mines; to show the relative importance of each method in terms of tonnages mined and man-hours consumed; to give to the mining engineers and particularly to the young student of mining a better understanding of the principal mining methods; and to indicate changes now in progress and to present suggestions for improvements in the art of mining. Questions of mine development and details of underground practice such as drilling and blasting, loading, hauling, hoisting, ventilating, pay systems and mine management are omitted, as these have been or will be discussed in other bureau publications.

Jan 1, 1931

By Darren Thorton, David Sprott, Ian Brunton

Blasting causes movement of the rock and can be detrimental to the accurate delineation of the ore and waste regions within the resulting muck pile. The consequences can be ore loss and dilution. However, ore loss and dilution can be minimized and significant increases in profit can be realized if the movement can be accurately measured. Various methods have been used to measure muck pile movement including poly-pipe, chain and sandbags but these have been either inaccurate or impractical. The Julius Kruttschnitt Mineral Research Centre, JKMRC, has developed an electronic blast movement monitor that provides accurate three-dimensional movement vectors following a production blast. From this information, the ore block boundaries in the blasted bench can be adjusted to compensate for the measured movement and then ore recovery can be optimised. Following initial development of the prototype technology, the JKMRC further developed and demonstrated the system in actual production blasts at an open pit gold mine operated by Placer Dome Inc.

Jan 1, 2005