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By M. R. Anderton

"A hierarchical four-character code designed for geological and allied data may be used to log exploration drill-holes and store the information on magnetic media. The code is intended for use in semi-free format and permits the collection of as much, or as little, data as the geologist may require for the purpose in hand. A method of data storage by variable length records is discussed.Information may be retrieved by means of a simple enquiry language. Optional output facilities could allow the retrieval of data in a form suitable for direct input to a contouring package. The enquiry parameters and interrogation program can thus provide the interface between the data bank and associated application systems."

Jan 1, 2014

By Jacque Turgeon, Gontran Foy

"The Mineral Research Centre of the Quebec Department of Energy and Resources has worked extensively on the development of a dry process to extract pure mica flakes from a phlogopite ore. The liberation of mica from the gangue is effected basically by impact crushing, and the ground ore is screened into several fractions, each having a fairly narrow range of grain size. Each sized fraction is then fed to an air separator where heavy grains are separated from light flaky grains. Heavy fractions are returned to hammer mills where gangue minerals are ground finer and blocky mica particles are exfoliated. A second stage of screening is performed and each fraction is sent to an air separator. This sequence is repeated until mica products are virtually free of gangue. These different fractions are then treated in a cage mill in which mica flakes undergo a more orderly exfoliation along cleavage planes. The ground mica is again submitted to a final screening stage, after which each fraction constitutes a final commercial product.This process permits the recovery of about 70% of the mica contained in the ore. The over-all process will be described along with technical details of each unit operation. Recent work on a wet grinding method to produce very fine mica will also be discussed.IntroductionRecords of production of mica in Quebec date back to 1886. Production has been more or less continuous since that time, with peak activity during the war years. Production was interrupted in 1966, but started again in 1972 when Marietta Resources and Laviolette Mining and Metallurgical Corporation started their joint operation in Canton Suzor, northwestern Quebec. Mica deposits of more or less importance exist in different parts of Quebec, of which three have attracted attention in recent years: the Canton Suzor deposit, the Canton Lamy deposit and the Canton Chasseur deposit. The Suzor orebody was first identified by Carl Faesler in 1936, who described the rock as ""brown biotite in flakes half an inch in diameter, with interstitial augite, apatite and feldspar""."

Jan 1, 1982

By C. Butcher

Numerical simulations of straight tube hydroforming of a dual phase steel were performed using both upper and lower bound constitutive models for porous ductile materials. The Gurson model is based upon an upper bound approximation to the material behavior and thus overestimates formability. Conversely, a lower bound solution to Gurson's unit cell geometry was developed by Sun and Wang to provide a conservative estimate of formability. The effect of a compressive axial load (end-feed) on damage development and tube formability is investigated. The resulting upper and lower bound models successfully captured the experimentally determined burst pressure, formability and failure location.

Jan 1, 2010

By Pete G. Kovalchik, Lynn A. Alcorn, Rudy J. Matetic, Adam K. Smith

Over-exposure to noise remains a widespread, serious health hazard in the U.S. mining industries despite 25 years of regulation. Most other categories of illnesses and injuries associated with mining have improved, with the exception of hearing loss. Mine Safety and Health Administration (MSHA) coal noise sample data collected from 2000 to 2002 show that 65% of the equipment whose operators exceeded 100% noise dosage is comprised of seven different types of machines. The continuous mining machine is first among all the equipment with 35% of the noise overexposures. The ational Institute for Occupational Safety and Health (NIOSH) is conducting research to reduce excessive exposure for operators of continuous mining machines and preventing additional cases of oise Induced Hearing Loss (NIHL) by developing low-cost retrofit noise controls for mining equipment. This paper describes a noise control for reducing the noise overexposures of continuous mining machine operators. Underground results show a 26.4% and 27.4% noise exposure reduction for the continuous mining machine operator. This research is providing the mining community with an additional noise control to be utilized on continuous mining machines, therefore reducing operator noise overexposure. Utilizing this newly developed noise control, along with previously proven controls for the continuous mining machine chain conveyor, will provide operators of these machines an opportunity to be within the MS HA-Permissible Exposure Limit (MSHA-PEL).

The modern resource extraction enterprise is a complex capital intensive business operating in a world of constantly evolving social, environmental and economic scrutiny. Investors, government, media and special interest groups expect to see business environmental and social performance respond and deliver increasing corporate responsibility and sustainability.   Thorough interrogation of business performance using a multi-disciplinary due diligence approach presents a more sophisticated review and benefits beyond the traditional compliance/conformance 'audit' style assessment.   Using a due diligence approach allows assessment through a comprehensive lens which examines potential short- and long-term risks including sometimes less tangible environmental and social liabilities, and informs management, investors and regulators of broader business performance. This approach provides information in a form that business can measure performance in a repeatable and enterprise wide sense.   This paper provides an outline of the due diligence process applied in this way, drawing from lessons learnt and industry based experiences in the due diligence process and the benefits and tools that can  be applied in an environmental and social due diligence business performance assessment

Jun 1, 2010

By S. Huang, K. Xia

"During crushing, rock particle is subjected to complicated loading and the particle shape influences the fragmentation outcome. Thus, a highly controlled laboratory test is desired to establish the relation between the loading and the fragmentation parameters for better understanding the rock crushing mechanism. In this work, a split Hopkinson pressure bar system in combination with high speed cameras is utilized to carry out a dynamic ball compression test, in which the spherical rock sample is adopted to avoid the shape effect. Using the elasticity theory, the history of the axial symmetric tensile stress perpendicular to the diametrical direction along the loading axis is determined, from which the loading rate and the dynamic indirect tensile strength are calculated. With the aid of the moment-trap technique, the total energy absorbed by samples is accurately determined from the one-dimensional wave analysis. Furthermore by considering the kinetic energy of the sample fragments using the high speed camera snapshots, the surface energy is determined for each sample. The relations between the loading rate and the fragmentation parameters, i.e., the number of fragments and the surface energy are established. The application of this method to a granitic rock shows that it is flexible and can be applied to the crushing study of generic brittle solids. INTRODUCTIONCrushers are widely used to break rocks to extract specific minerals in the mining industry, and to obtain rock fragments with desired size distribution in construction industry. During crushing, the breakage of particles can be in either the single-layer mode or the multi-layer mode. In the single-layer mode, the particle breakage can be assumed to be isolated, in which the interaction between particles can be ignored. It is thus suggested by many researchers that highly controlled single particle test should be performed to establish the relation between the input mechanical energy and size reduction for better understanding the crushing mechanism (Yashima et al., 1987; Tavares, 2007; Pitchumani et al., 2004)."

Jan 1, 2015

By T. E. Warner

In order to detect arsenic and antimony in zinc, various electrochemcial experiments were performed involving the electrochemical introduction of sodium atoms into molten zinc using a solid electrolyte. Under high rates, the formation of the intermetallic phase NaZn13 was assumed to form. Under more moderate injection rates of sodium, employing a symmetric "zinc/zinc cell", a qualitative relationship between the current generated during cyclic voltammeuy and the arsenic and antimony concentrations in molten zinc was observed.

Jan 1, 1999

By G Fergus, M Hart, S W. Weeks

Rio Tinto Alcan has undertaken feasibility level assessments into the expansion of its bauxite mining operation in an area south of the Embley River in far north Queensland. The project has the potential to extend their Weipa operations by approximately 40 years.The construction and operation of two additional mineral ore processing plants are proposed for the South of Embley project. Golder Associates was engaged to develop and conduct modelling assessments of potential sources of water supply required by mineral ore processing.Two models were developed using GoldSim: a dam yield model and a water balance model. GoldSim is a graphical object-oriented modelling environment with a capacity to carry out dynamic probabilistic simulations. Originally developed by Golder, GoldSim has been applied successfully in a decision support role to a range of mine water management operations.The dam yield model was used to provide estimates of reliability and volume of annual water supply of several potential surface water dams. This information was then used to determine a hierarchy of water supply options for processing plant operations. The water balance model dynamically simulated the water demands of the two production plants and the consequential response in water supply, with respect to the timing and discharges provided by the various source options.Use of the model provided a preliminary operational tool to assist with water supply management decisions. Water quality issues required a blending of water from separate sources and attention paid to scheduling to ensure water supply through the dry season. The model also helped identify risks to water supply in the event of underperformance of one or more water supply sources. This allowed the operational rules to be refined to minimise those risks.The dynamic and stochastic modelling approach provided a method for identification of water supply issues susceptible to seasonal climate variability.CITATION:Weeks, S W, Hart, M and Fergus, G, 2013. A dynamic evaluation of water supply security susceptible to climate seasonality, in Proceedings Water in Mining 2013, pp 197-208 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By Reid K. J, Restarick C. J

The breakage and flow characteristics of quartz, ground as a minor constituent with calcite in a continuous wet ball mill, have been determined by carefully controlled grinding tests.A mathematical model, combining the simple functions which describe these characteristics, has been used to predict both steady state and non steady state results.The calculated results are compared with experimental data.

Jan 1, 1966

By E. V. Verhoef

The proposed EU directive on the restriction of the use of certain hazardous substances in electrical and electronic equipment promotes the substitution of lead in consumer electronics to reduce emissions from lead in the end of life phase. In this paper, the consequences of substituting lead in solders is assessed using the Eco-lndicator-99 method for the examples. The base metal production system is considered as an interconnected network modeled dynamically in Simulink 4 and Matlab 6 (Mathworks Inc 2000), where the recovery and production of metal components of the assessed product partially overlap. This approach requires global modeling of metal production processes and mass balances and resulting allocation choices. It also reveals the susceptibility of LeA scores to different choices in the modeling and data availability and uncertainty. Besides the comparison between lead-free and lead-containing solders, other side effects are revealed. Lead is carrier material for the recycling and production of many co-elements in the interconnected production and recovery system. Substitution may have adverse effects such as temporary shortages of other connected metals that are often not considered in normal LeA assessments, thus leading to erroneous results. The suggested approach provides directions for including these external effects and for further assessment of the environmental effects of substituting lead. This paper shows that in order to assess the environmental aspects of metallurgy, dynamic modeling of the total system is required based on the fundamental thermodynamics in each metallurgical reactor, the basis of this dynamic model. With this the true environmental impact of metallurgy can be explained. In the case of lead free solder, it is shown that the mining of substitutes has a very much larger impact.

Jan 1, 2003

By E. V. Verhoej

The proposed EU directive on the restriction of the use of certain hazardous substances in electrical and electronic equipment promotes the substitution of lead in consumer electronics to reduce emissions from lead in the end of life phase. In this paper, the consequences of substituting lead in solders is assessed using the Eco-Indicator-99 method for the examples. The base metal production system is considered as an interconnected network modeled dynamically in Simulink 4 and Matlab 6 (Mathworks Inc 2000), where the recovery and production of metal components of the assessed product partially overlap. This approach requires global modeling of metal production processes and mass balances and resulting allocation choices. It also reveals the susceptibility of LCA scores to different choices in the modeling and data availability and uncertainty. Besides the comparison between lead-free and lead-containing solders, other side effects are revealed. Lead is carrier material for the recycling and production of many co-elements in the interconnected production and recovery system. Substitution may have adverse effects such as temporary shortages of other connected metals that are often not considered in normal LCA assessments, thus leading to erroneous results. The suggested approach provides directions for including these extemal effects and for further assessment of the environmental effects of substituting lead. This paper shows that in order to assess the environmental aspects of metallurgy, dynamic modeling of the total system is required based on the fundamental thermodynamics in each metallurgical reactor, the basis of this dynamic model. With this the true environmental impact of metallurgy can be explained. In the case of lead free solder, it is shown that the mining of substitutes has a very much larger impact.

Jan 1, 2003

By P. Nelson, B. Salt, J. A. Scott, H. Shang

ABSTRACT In a nickel smelting process, large amounts of off-gas emissions are generated, which can cause serious environmental and plant hygiene problems if not properly treated. With increasingly stringent environmental regulations, an enhanced understanding of well-controlled, off-gas cleaning systems is vital. In this paper, dynamic models for an industrial smelter, off-gas system tackling hazardous sulphur dioxide, carbon monoxide, and carbon dioxide are developed using mass continuity, momentum, and energy conservation laws. The effect of air in-leakage is explored under different operating conditions. The developed models provide an enhanced process understanding and a necessary basis for highperformance control analysis of smelter off-gas systems.

Jan 1, 2011

By Jaczkowski B

The lower orebody (LOB) at Chingola Divi- sion of Nchanga Consolidated Copper Mines Limited (NCCM) accounts for approximately 30 per cent of the total copper production for the company. The uniformity of the geology of the orebody lends itself readily to a computer based ore reserve calculation and accounting system. The mining units are physically defined such that a hierarchical type of com- puter file organisation can reflect the existing physical interdependencies. In 1972, a project team consisting of one representative from each of the mine planning, operational research, and computer services departments was formed to investigate and to define the technical mining requirements of the dynamic ore reserve system (DORS). The system was finally implemented in 1975ò

Jan 1, 1977

By Kadri Dağdelen, Matthew Deutsch, Thys Johnson

Nested pit analysis in open-pit long range mine planning is used to define approximate ultimate pit limits and an initial high-level schedule in the early stages of a project. Modern ultimate pit optimizers can solve for dozens, or even hundreds, of nested pits however often a smaller subset of pits which are evenly spaced with respect to contained tonnage are desired for downstream analysis. In situations where that pushback selection process must be automated, such as when performing sensitivity analysis, or when the best subset of pushbacks is required; an optimization procedure is warranted. This paper describes a dynamic programming algorithm for selecting pushbacks following nested pit analysis, which is performant and addresses a long-standing inconvenience faced by long range open-pit mine planners.

Jun 25, 2023

By M Ind, B Usher

Environmental regulators are increasingly adopting risk-based approaches to protect aquatic ecosystems. The Australian and New Zealand Environment and Conservation Council (ANZECC) and the Agriculture and Resource Management Council of Australia and New Zealand (ARMCANZ) (2000) introduced a risk-based approach to water quality guidelines that use decision frameworks to adapt water quality guidelines to local environmental conditions. Environmental quality objectives are no longer a simple ‘pass or fail’ number such as restricting total suspended solids (TSS) concentration to a specified limit for a particular rainfall event. This approach ignores spatial and temporal variability and the complexity of aquatic ecosystems. The risk-based approach establishes levels where adverse effects may occur. If these objectives are not met, further risk-based investigation is undertaken to assess the potential impact to the ecosystem. Klohn Crippen Berger (KCB) developed a dynamic simulation to predict the variability of sediment discharges, which is applicable for risk-based impact assessment of aquatic ecosystems. The application of the methodology over the life of a mine site is illustrated using a proposed South Pacific mine.The site location is in extremely rugged terrain with a high annual rainfall of approximately 4.7 m. There were two major sediment ponds proposed to reduce sediment discharges. A sediment and hydrology model was developed in Goldsim to provide daily estimates of run-off flows and sediment concentrations. A modified algorithm based on the Australian water balance model was created and incorporated into the Goldsim model and calibrated using recorded field data.The sediment module was developed based on a Revised Universal Soil Loss Equation (RUSLE) assessment, an annual prediction of soil loss over a catchment. A land-use type erosion vector was developed for different land-use types and for each of the subcatchments, a subcatchment erodibility vector was calculated. This vector and the daily rainfall erosivity factor were used to estimate the daily soil loss. The estimated soil loss and the modelled run-off yielded predictions of daily sediment concentrations. Finally, a sediment settling module was used to predict the daily efficiency of the sediment ponds and hence discharged sediment concentrations.The results of this modelling form the first part of a quantitative risk-based assessment into suspended solids impacts. The second part is the assessment of the effects of these predicted TSS concentrations on aquatic ecology. As part of the feedback-loop required in a risk management framework, if the environmental quality objectives are not met then further management decisions and actions may be required to reduce the risks presented by suspended solids. This may include modifications to: the mine-development plan; construction techniques and scheduling; processing techniques; rehabilitation strategies; or hard-engineering solutions such as sediment basins or flocculation.The Goldsim water-balance model provides a quick and efficient method of testing potential remedial actions on predicted sediment loads and concentrations. In combination with a cost-benefit assessment, options for reducing sediment releases from the mine site can be effectively and quantitatively compared thereby providing mine operators with a basis for decision-making. Regulators can also be satisfied that potential impacts to aquatic ecology have been comprehensively assessed and the necessary management decisions have been initiated to limit risk to the environment.CITATION:Ind, M and Usher, B, ?2014. A dynamic sediment simulation to predict the variability of suspended solids concentrations over life-of-mine for application to a risk-based environmental assessment, in Proceedings Life-of-Mine 2014 , pp 191–204 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By P. Mottahed, E. De Souza

One of the major unsolved problems of safe, economical roof support in the evaporite industry has been that of obtaining and maintaining anchorages in relatively soft rock. This is due to the viscoelastic and viscoplastic behaviour of salt rock and associated deposits. This paper introduces a low-cost, yieldable support mechanism, consisting of a system of buckling disks, which provides viable solutions to dynamic support. The yieldable support system offers a number of advantages in comparison with existing dynamic support systems. It is characterized by its simplicity in design and installation, repeatability in behaviour and cost effectiveness. It also has the added advantage of providing the operator with a means of assessing support behaviour and ground performance by direct visual observation of changes in disk shape. Thus, the system can be utilized as a warning mechanism of ground stress and support load conditions. Such system not only provides a feasible and more effective rock mass stabilization strategy but improves mine safety.

Jan 1, 1999

By M. Wickham

Design of an open pit backfill requires an understanding of highly varied processes including slope stability, hydrogeology, pit lake chemistry, climate, runoff, and mine waste behavior. Dynamic systems modeling (DSM) provides flexibility to the designers of open pit backfill, allowing them to directly integrate many different physical processes and varying levels of complexity. DSM also provides for the efficient application of uncertainty analysis to define a range of possible results, the sensitivity of the results to uncertainties in model inputs, and the value of additional data. This paper presents the results of an analysis using DSM to evaluate a pit backfill design at an Arizona mine. The objective of the partial backfill was to stabilize an active slope that threatened facilities adjacent to the pit. DSM was used, in part, to develop a pit lake water balance model for evaluating the influence of the backfill on the ability of the pit to maintain passive hydraulic containment of groundwater and surface water inflows and for evaluating costs for various backfill scenarios.

Jan 1, 2001

By Adriano Corrêa Batista, Bernardo Antônio Perez da Gama, Camila Freitas de Araújo, Paulo Santos Assis

O mexilhão dourado Limnoperna fortunei é uma espécie invasora que tem causado diversos problemas no ambiente aquático em razão da sua habilidade de formar colônias em estruturas. A espécie adere nas superfícies por filamentos proteicos, causando sérios danos ambientais, sociais e econômicos.O combate à incrustação biológica através do tratamento de superfícies submersas em ambientes de água doce com produtos naturais, em especial os oriundos de algas vermelhas, é o desafio apresentado.Com o banimento, em dimensão mundial, de insumos à base de tributilestanho - TBT na composição de tintas, desde 2008, tratamentos alternativos e ambientalmente adequados ganham maior apelo, considerando os riscos dos produtos alternativos atualmente aplicados. É descrito um conjunto de condições para espécies produtoras de metabólitos secundários com atividade anti-incrustante importante. Portanto, o trabalho tem como objetivo reforçar uma linha de pesquisa ampla dedicada a consolidar informações sobre o potencial de organismos marinhos como produtores de metabólitos secundários (produtos naturais) com atividade anti-incrustante, à luz da produção científica a ser analisada no espaço destinado à apresentação de resultados.

Nov 6, 2019

By Fabio Tavares Chamonge

Este trabalho visa mostrar os principais benefícios alcançados na qualidade dos produtos e a evolução da produtividade nas linhas de produção da Laminação a Frio com a estabilização operacional da nova Decapagem. Os recentes investimentos na modernização tecnológica, com a aquisição e implementação da nova Decapagem com os recursos modernos de controle e automação permitiu que houvesse uma evolução significativa da qualidade dos produtos, eliminando o desvio, reduzindo o descarte e melhorando a produtividade ao longo do processo de fabricação. Com inicio de funcionamento da nova Decapagem possibilitou processar bobinas com maior peso, maior flexibilidade na formação de bobinas soldadas e menores descartes por qualidade, estes fatores afetaram positivamente o peso médio na saída da Decapagem. A melhoria do material processado na nova linha proporcionou elevação da produtividade do Laminador de tiras a frio, considerando os aspectos: oleamento, planicidade, peso de bobina, solda e isenção de manchas e defeitos superficiais. O processo de Encruamento também foi beneficiado com peso de bobina e melhoria da forma do material. O produto final e os processos de acabamento também tiveram impactos positivos dos resultados obtidos na Decapagem 3.

Aug 16, 2017

By Leonardo Silva Motta

O carbureto de cálcio tem sido empregado em novas tecnologias para desoxidação e dessulfuração de aços de maneira crescente. A metodologia consiste na realização de um cronograma de projeto contendo dez atividades. Nos últimos anos houve aumento em cerca de 30% na utilização de carbureto de cálcio na metalurgia secundária das usinas brasileiras. Além desse expressivo aumento, vários trabalhos técnicos são apresentados todos os anos atestando as eficiências técnica, energética e financeira do carbureto de cálcio na produção de aço.

Jul 30, 2018