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By Ulf B. Andersson, Christina Dahnér-Lindkvist, Bruno Figueiredo, Jessa Vatcher, Jonny Sjöberg, Joel Andersson

Hydraulic fracturing to precondition the rock mass in high seismic risk environments has great potential. Unfortunately, there are many unanswered questions about how to best implement a hydraulic fracturing program at individual mine sites, and even how to best use our engineering tools to evaluate these plans. To give the hydraulic fracturing field tests at LKAB’s Kiirunavaara Mine the best chance of success, fully-coupled, discontinuum numerical modelling Itasca’s 3DEC code was used together with statistical simulations of the fracture network. For modelling purposes, it was assumed that hydraulic fracturing successfully reduces seismic risk through 1) the creation of hydraulic fractures along a plane at each injection site, and 2) activation of existing discontinuities. A variety of scenarios for the mine were evaluated, which focused on site specific uncertainties (such as the spacing of the pre-existing discontinuities) and practical solutions (such as the hydraulic fracture spacing, selection of injection medium, and hydraulic fracture site location relative to production). The discrete fracture network (DFN) realizations were developed using available statistical data for discontinuities near where hydraulic fracturing was planned.

Apr 26, 2022

By J. M. Tranquilla

EMR Microwave has developed several unique processes for the pretreatment of refractory gold and copper ores. This report describes a recent large scale pilot project involving a carbonaceous gold-bearing whole ore. Pilot plant testwork conducted jointly by EMR and Bateman Engineering Inc. has shown that 90+% cyanide soluble gold recovery is obtainable from refractory (sulphide and carbonaceous) Carlin, Nevada gold ores. Typical cyanide soluble gold recoveries for untreated material is 20%. AC energy consumption was found to be between 58.l kWh/ton and 15.5 kWh/t for an assumed heat recovery of 50% and 80% respectively. The plant was operated at reduced temperatures ( 400°C) from previous testwork on similar ore at 600°-700°C.

Jan 1, 2000

By David R. Crouthamel, Francis L. Fong, Troy L. Page

This paper focuses on the results and the performance of the grouting program as a means to control groundwater infiltration during the excavation of the 7.7 km (25,160 lf.), 3.5m (11 ft. - 7 in.) diameter Inter-Island Tunnel beneath Boston Harbor in Massachusetts. Two major operations of grouting were performed - water cutoff grouting behind the tunnel heading after excavation and face grouting ahead of the Tunnel Boring Machine (TBM) operation. An array of products from cementitious to chemical grouts and various grouting procedures and equipment were employed to evaluate their effectiveness in controlling the water in-flows. Evaluation of the overall performance of each of the grouting rations, overall costs and comparison of face grouting versus post excavation grouting is made.

Jan 1, 1997

The Pennsylvania State College, Mineral Industries Experiment Station, State College, Pa For publications address the Director The Pennsylvania State College through the Minerals Research Experiment Station has issued 10 Bulletins and three Technical Papers, from which the following have been selected as of greatest interest to mining engineers and geologists: Bulletin 1, An investigation of the properties of smitliing coals (1922), free; 2, Petrography of the Mica Pendotite Dike at Dixonville (1926), free; 4, The Helderberg Group from cen¬tral Pennsylvania to southwestern Virginia (1929), 25 cents, 5, Bentonite in Pennsylvania (1929), 10 cents, 6, Production data on Appalachian oil fields (1930), free; 8, Oil field waters of Pennsyl¬vania (1930), free; Technical Paper 2, Condition of water in coals of various ranks.

Jan 1, 1933

By AIME AIME

THE Petroleum Division held a very successful meeting in Los Angeles, Oct. 4 and 5. The meeting was held on the eighth floor of the Chamber of Commerce building, the first day being devoted to technical sessions. Seventy-five members were registered before the opening of the first session. Glenn D. Robertson, vice-chairman of the local section, opened the meeting and introduced Edwin Higgins, managing director of the California Oil and Gas Association, who gave an interesting talk on the recently enacted gas conservation law in California. He explained that the law is an experiment which will be watched with a great deal of interest. The purpose of the law, which went into effect on Sept. 1, is to curb wastage and over-production of gas,

Jan 1, 1929

Nov. 4, 1952, AIME, Morenci Sub-section, Longfellow Inn, Morenci, Ariz. Nov. 5, AIME, Chicago Section, Chicago Bar Assn., Chicago. Nov. 8-8, New Mexico Mining Assn. and International Mining Days, joint convention, Alvarado Hotel, El Paso. Nov. 7, AIME, Pittsburgh Section, National Open Hearth Steel Committee, off-the-record meeting, Hotel William Penn, Pittsburgh. Nov. 7-8, Birmingham Technical Meeting of Southeast Section, AIME, Birmingham. Nov. 10-11, Eighth Annual Meeting of The Magnesium Assn., Hotel Biltmore, New York City. Nov. 12, AIME. Connecticut Section, Hartford, Conn. Nov. 18, AIME, Buffalo Section, National Open Hearth Steel Committee, Hotel Statler. Buffalo. Nov. 19, AIME, Connecticut Section, Hartford, Conn. Nov. 19, American Mining Congress Coal Div. Conference, Wm. Penn Hotel, Pittsburgh.

Jan 1, 1952

By R. B. Stroud

This report, part 3 of a series, describes and gives results of field. investigations by the Bureau of Mines on manganese resources of the Batesville district, Arkansas, from July 1956 through June 1961. The purpose of the Bureau's work was to evaluate the manganese potential of the district in fur- therance of the Government's program with respect to domestic resources of critical and strategic minerals. The work comprised areal reconnaissance, mapping, churn and core drilling, and sampling. In more recent years, the investigations were confined to manganiferous limestone, which constitutes a significant potential resource of manganiferous material. The resources of manganiferous material in the district are inferred to be on the order of 198 million long dry tons averaging between 4 and 5 percent manganese.

Jan 1, 1964

By David Shuck

On November 1991, Homestake Mining Co. completed the installation of a $5.7-million, 2.7-kt/d (3000-stpd) flotation circuit into the flowsheet of the McLaughlin Mine in California's coastal mountain range, about 113 km (70 miles) north of San Francisco. This addition reduced overall operating costs and improved the gold recovery of the low-grade refractory reserves over that expected from direct cyanidation. In addition, flotation provided a means to generate a sulfide concentrate that is used to supplement feed to the pressure oxidation circuit. The McLaughlin operation started in 1985 as the first pressure oxidation plant for treating sulfide refractory ore. During the mine's short history, efforts have been made to reduce costs and increase production through process development.

Jan 1, 1994

By David S. Butts

The high cost of energy has made many solution mining corporations turn from fuel consuming evaporators to solar energy and solar ponds. The generally held concept of a solar pond is an area enclosed by dikes into which brine is pumped, water evaporated by the sun, and the resulting salts scraped from the bottom of the pond. This paper will show that solar ponding is not simple. It is a science involving six main areas. These areas are (1) land conditions, (2) meteorology, (3) fresh water, (4) accessibility, (5) manpower and (6) mineral resources. Each area is discussed to identify important parameters that must be investigated before the viability of a solar pond complex can be established as a mineral recovery step.

Jan 1, 1985

By Fu Lizhu, Qiu Tingsheng

An application of water-system magnetizing technology for the mineral processing and hydrometallurgy is introduced in this paper. The water-system magnetizing technique flotation and cyanidation leaching test of vein-ore of gold-bearing and conventional technique flotation and cyanidation leaching of gold-bearing vein-ore was carried out. The best condition of water-system magnetizing was determined by orthogonal test. The results have shown that the water-system magnetizing technology may increase the efficiency of flotation and cyanidation leaching for gold. The industry-scale test results also show that it can increase flotation recovery by 1-3% and leaching extraction by 3-5% of a gold-bearing vein- ore. The interaction of magnetizing water-system with minerals was carried out and initially investigated.

Jan 1, 1995

By Charles L. Elliot

Worldwide manpower utilization reached a new high at 10,482 professional man-months and expenditures increased to $19.9 million for mining geophysical activity during 1965. This is up from 9323 man-months and $14.5 million in 1964. Worldwide geophysical activity measured in percent distribution of the total manpower utilization and expenditures is presented in the accompanying Figs. 1 and 2. In terms of the total manpower utilization, ground surveys accounted for 61%, airborne surveys 18%, and mining geophysical research activity 21%. For expenditures, the breakdown was ground surveys, 49%; airborne surveys, 3901o; and research, 12%. Industry was responsible in general for 74% of the manpower utilization and 80% of the expenditures. Manpower costs in 1965 averaged $1900 per professional man-month.

Jan 11, 1966

By Michael Samis

Conventional project valuation techniques, such as discounted cash flow (DCF) method, are more frequently being criticised for the manner in which they consider the interacting effects of uncertainty and project structure (including management flexibility) on project value. Modern asset pricing (MAP; often called ?real options valuation? when applied to the analysis of flexibility) is a more general valuation framework that corrects many of the shortcomings of common valuation methods. Previous mining applications of MAP have tended to treat the ore deposit as a homogenous entity. While useful for demonstration purposes, this is inadequate for practical application in industry. This paper presents a MAP valuation example that allows for the heterogeneous nature of an ore deposit. It shows that deposit structure may increase the complexity of the mine planner?s decision so that results of a standard DCF analysis, or a simple MAP analysis that ignores the details of deposit structure, are misleading. In the example, a management is considering the development of an adjacent low-grade zone while mining operations in a high-grade zone are ongoing. If the low-grade zone is developed before high-grade reserves are exhausted, the proposed development will include both low-grade zone development and a capacity expansion to handle additional low-grade reserve production. If development of these reserves is delayed until the high-grade reserves are depleted, then the low-grade reserves can be developed without a capacity expansion. A typical DCF analysis would reduce the management?s decision problem to three alternatives: 1) continue mining only in the highgrade reserves, 2) immediately develop the low-grade reserves and expand capacity, and 3) delay low-grade zone development until the high-grade reserves are exhausted. The model presented here allows the management to reconsider the development and capacity expansion decision on a discrete half-year basis. It delineates price regions, for given levels of high-grade zone reserves, in which it is optimal to develop the low-grade zone, defer low-grade zone development and abandon the mine irrevocably. The model presented here extends the ability of mine planners to describe actual project structure while using the MAP valuation framework that is already noted for its capacity to combine project uncertainty and risk insights with a dynamic project description.

May 1, 2001

By Tajebe Bezabih, Tonya Sanders Thach, David Sinkhonde, Samia Kirchner, Hunter James, Derrick Mirindi

With the increasing demand for wood driven by population growth and urbanization, this study explores the potential of three-layer particleboards reinforced with waste fibers as a sustainable and eco-friendly alternative in building material technology. It focuses on various waste fibers such as sisal, bagasse, leather shavings, and waste papers, assessing their impact on the structural properties of particleboards. The research thoroughly evaluates key mechanical properties such as the modulus of rupture (MOR) and modulus of elasticity (MOE), as well as essential physical properties like water absorption (WA) and thickness swelling (TS). This investigation delves into the innovative use of organic and natural bio-waste particulates as reinforcing agents in polymer composites, specifically examining their role in enhancing particleboard characteristics. A significant finding of this study is that the enhanced particleboards not only meet, but sometimes exceed, the minimum standards set by various international guidelines for general purposes. This indicates that it is feasible to replace traditional wood fibers with certain organic waste materials while maintaining or even improving the performance of conventional particleboards. This advancement is particularly relevant to the construction industry, as it suggests that these improved particleboards can be effectively used as sustainable structural materials. By utilizing waste fibers, it not only aligns with global sustainability goals but also provides a practical solution for waste management across multiple industries. Consequently, this research represents a significant step forward in the development of building materials that support eco-friendly construction practices and contribute to the circular economy.

Oct 7, 2024

By João Alberto Fioresi Altoé

Nas indústrias petroquímicas, nucleares e farmacêuticas o avanço tecnológico tem como objetivo a segurança e confiabilidade dos equipamentos com relação à resistência mecânica e à corrosão. Atualmente, o uso dos aços inoxidáveis superausteniticos é uma solução interessante, para uma maior vida útil dos componentes industriais submetidos a ambientes agressivos, como em meios salinos. Esse trabalho tem como objetivo investigar o aparecimento de pites em um aço comercial superaustenitico de composição química aproximada 25Cr28Ni4Mo em solução salina de cloreto de sódio. O aço foi fundido e tratado termicamente por solubilização a 1050ºC por 1h com o objetivo de eliminar os precipitados. As análises microestruturais antes e após os ensaios de corrosão foram feitas por microscopia óptica e eletrônica de varredura. Observou-se com os ensaios eletroquímicos de Polarização linear e impedância, que o aço inoxidável superaustenítico apresenta excelente resistência à corrosão em meio salino, caracterizado também pelas imagens que não revelaram a formação de pites, mesmo quando submetidos a elevados potenciais.

Aug 16, 2017

By Brabcova Z.

This contribution deals with bubble adhesion on particle surface which consists of three steps ? the liquid film thinning, the film rupture and expansion of the three phase contact (TPC). Our attention is devoted to the third step ? to the description of the TPC expansion. Three-phase contact line expansion can be theoretically described using hydrodynamic and molecular-kinetic models. Both of these models were originally developed for the interaction of the bubble with horizontal plane in pure water. Our experiments deal mainly with the interaction of the bubble with the inclined plane in the solution of surface active agents. It was proved experimentally that molecular-kinetic model corresponds also to these conditions and this model was used for the description of the TPC expansion. The model is based on the theoretical description of the bubble contact angle on the three-phase interface. These contact angles change dramatically from 180o to equilibium (Young) contact angle close to 90o. Modificated ADSA method is used for the calculation of the contact angle. This method utilizes the Laplace equation of the capillarity; the bubble profile and the contact angle are evaluated using the set of experimental points around the edge of the bubble. The comparison of the experimental and calculated bubble profile shows a good agreement. The aim of the project is to describe the process of the TPC expansion during the adhesion of the bubble with the diameter up to 1 mm. Inclined planes were used instead of an experimental solid particle. Our experiments were provided in the solution of surface active compounds. The process of the adhesion was recorded using high-speed digital camera and images were evaluated using the image analysis software NIS-Elements. Calculations were performed using the MATLAB software. Keywords: bubble-particle interaction, adhesion, three-phase contact, contact angle

Sep 1, 2012

By Nelson SOUTO, Nicolas LEGRAND, Christian COUNHAYE, Don EARLEY

The work is motivated by the automotive customer requirements for a roughness with high peak density (RPc > 75 peaks/cm) on steel sheet surfaces to maintain a good strip surface finish after painting. For that purpose, a new approach is utilized to compute roughness transfer and predict final roughness on uncoated steel sheets (average roughness, skewness, peak density) as a function of temper rolling conditions. The approach is based on the Monte Carlo method combined with the Abott curves and an auto-correlation function to numerically generate roughness profiles for roll and strip respectively. To compute the roughness transfer due to the interaction between roll and strip surfaces during rolling, a composite Abott curve that combines roll and strip Abott curves is used with an asperity crushing model integrated with a rolling model. This enables simulating two roughness transfer mechanisms in the roll bite: the strip asperity crushing mechanism by roll roughness and the strip asperity ploughing mechanism due to roll-strip interfacial sliding speed. The model shows the importance of considering the two mechanisms to predict roughness transfer correctly when strip elongation is high, typically a few percent, and roll bite friction is low. In these conditions, the forward slip at the exit of the roll bite tends to erode strip roughness significantly and decrease considerably the peak density on the strip. For lower elongation levels (~1%) and high roll bite friction, the ploughing mechanism becomes negligible and roughness transfer is controlled by the crushing mechanism only. With these two mechanisms, the model reasonably predicts the evolution of average roughness and peak density over a wide range of temper rolling conditions (new/worn work rolls, hard/soft grades, various elongations), but skewness is more difficult to predict for some trials.

Oct 1, 2019

By Caio Luca Joppert

O objetivo do trabalho foi estudar a possibilidade de ajustar as características do biogás produzido a partir da fermentação de vinhaça de modo a torná-lo intercambiável com o Gás Natural (GN), ou um GN substituto (GNS) com características que permitam introduzi-lo na rede de distribuição. São considerados aspectos normativos e técnicos associados à composição química e comportamento durante processo de combustão visando o atendimento aos requisitos normativos estabelecidos para o GN. O trabalho considera a vinhaça, rejeito da produção de etanol a partir da cana-de-açúcar, como fonte para produção do biogás em razão da grande disponibilidade deste resíduo do setor sucroalcooleiro. O Estado de São Paulo (ESP) é tratado com destaque, uma vez que este concentra a maior parte da produção do setor sucroalcooleiro no Brasil. Cálculos de razões de mistura tratada com gases de ajuste foram realizados para verificação das proporções necessárias que viabilizam a utilização da mistura como GNS, tendo como referência especificações da ANP. Os resultados do estudo indicam que a alternativa de geração e beneficiamento de biogás da vinhaça é uma opção tecnicamente viável de conversão de fração considerável deste resíduo do setor sucroalcooleiro em gás com características similares ao GN. Ademais, a alternativa proporciona a valoração do conteúdo orgânico do resíduo, com redução da contaminação dos solos no processo de reaproveitamento dos nutrientes nos processos de fertirrigação.

Jul 31, 2018

By R Stosch, D Lohberger, J Rodler, E Schnell and A Bassler, H Ramseier

In the last two decades three-dimensional (3D) computational fluid dynamics (CFD) simulations have become an important tool in engineering sciences. More recently, the safety requirements in underground railway stations have increased with regard to incidents. For this reason, existing underground stations (eg Munich, Strasbourg and Berlin) are being equipped with smoke extraction facilities to protect passengers from smoke and visibility impairment in the event of fire. In addition, designs of planned underground stations (eg Karlsruhe, Doha) also include these facilities.For the commissioning of ventilation engineering systems with complex structures, the functional testing of the whole technical installation are important, as are the acceptance tests of ventilation and equipment parts. This functional testing includes not only the technical inspection of the equipment but also the acceptance measurements of the capability of the equipment and the execution of hot- or cold-smoke tests to confirm the effectiveness of the ventilation system.Due to the fact that the overhead contact line and other sensitive installations were already installed in the tunnel roof at the time that smoke tests were proposed, hot-smoke tests with fire loads up to a maximum of 1 MW could only be executed. Therefore, the evidence of the attainability of the safety objective had to be provided computationally in this special case with a fire scenario of a heat release of 10 MW using CFD simulations.This paper presents the interplay between the results from acceptance testing and smoke tests and the use of 3D CFD simulation and virtual reality using the example of Allmend station, which was repositioned underground and is part of a new section of track from Lucerne railway station to Kriens in the Zentralbahn network. The steps of the verification and validation of the computer model are presented with the real tests and measurements.CITATION:Stosch, R, Ramseier, H, Lohberger, D, Rodler, J, Schnell, E and Bassler, A, 2014. Safety in underground railway stations – an example of the interplay between testing and 3D computational fluid dynamics simulation, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 103–112 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By Saurav Kumar, Akshay Kumar, Vinayaka R. Kiragi, M. K. Banerjee, Amar Patnaik, Vinod Kumar

Today’s industrial technology offers to optimize and reutilize the resources available in terms of scum that remains after hot rolling in steel rerolling mills in Rajasthan, India. Vast reserves of low-grade coal exist and tons of mill scale are produced everyday after hot rolling in steel rerolling mills in Rajasthan, India. The present research work aimed to optimize the various parameters of solid-state reduction of mill scale using low-grade coal from Rajasthan, India. This study investigates the effect of reduction temperature (850–950 °C in steps of 50 °C), reduction time (60 to 180 min, in step of 60 min), mill scale size (800– 300 μm), and mill scale to coal ratio (1:1, 1:2 and 1:3) on achievable metallic iron percentage and its metallization. A higher percentage of iron content is obtained at a lower particle size of 300 μm. The structural analysis is carried out on 300 μm mill scales using XRD analysis, which shows the percentage of iron is approximately 63%, and metallization above 80% can be obtained under the reduction temperature at 900 °C for 180 min, for 1:3 ratio (mill scale to coal ratio). The chemical composition of the mill scale is obtained using X-ray fluorescence (XRF), and particle sizes as well as distribution of mill scale are determined by scanning electron microscopy (SEM). The elements present in the mill scale are also verified using EDS, which indicates the presence of a major portion of Fe, followed by Fe2O3, Si, and C, respectively.

Aug 14, 2020

By F. Aurelian

The development of the uranium mining industry in Romania started in 1950. The exploitation of Bihor region, one of the most important metallogenic zones of the country, began in 1962. Uranium exploitation activities were ceased in 1995 due to the exhaustion of the ore deposits. Between 2001 and 2002, due to the entire mining zone closure, ecological rehabilitation and decommissioning was initiated. The proposed solutions, concerning terrain, equipment and buildings utilization were elaborated according to the guidelines of the Romanian Environmental and Nuclear Authority.

Jan 1, 2006