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By Elizabeth Wademan

Recessions Eventually End ??Companies aggressively cutting production and inventories ??these will come in-line with demand ??U.S. home inventories are declining ??Housing becoming more affordable ??Global trade recovering after collapsing ??Lower oil prices should act as a stimulus Protracted Deleveraging Process Beginning ??Era of leverage-driven consumption is over ??Greatest destruction of consumer wealth since WWII ??Consumers will no longer be able to substitute capital gains for savings ??Shift towards savings will be a headwind to economic growth ???Paradox of Thrift?

May 1, 2009

By S. A. Hosseini, O. Asghari

"Recoverable mineral resources assessment has become a standard geostatistical application in the mining industry, with various geostatistical techniques currently available. This investigation aimed to improve the prediction at the Sungun deposit and to obtain mineral resource models capable of handling (i) the change of support from drill-hole composites to selective mining units (SMUs), (ii) the multivariate nature of the ore control selection criteria that involves both copper and molybdenum grades; and (iii) the local uncertainty on the true (unknown) grades. The solution presented in this paper is to use direct block-support sequential cosimulation in order to construct a set of alternative outcomes of the copper and molybdenum grades on block support over the deposit, with no need for storing point-support values, hence with a considerable gain in memory management and CPU time. The grade realizations so obtained are then processed to calculate the uncertainty in the mineral resources that can be recovered above given cut-off grades, both globally and on a blockby- block basis. IntroductionGeostatistical methods are widely used by mining companies to determine a resource model of the tonnage and head grade of a potential orebody, which is one of the first and most critical inputs underpinning any mining project. The prediction of the grade, tonnage, and recoverable metal for a particular mining plan and the corresponding financial forecast constitute the main technical risks in mineral resource evaluation. The conventional approach to this problem is to predict the mineral grade for constant volumes relevant to the mining plan and to base the recoverable mineral resource calculations on those predictions. Alternatively, one can directly predict the local variability in the mining block grades based on a spatial distribution model (David 1988; Rossi and Deutsch 2014). Multiple realizations can also be constructed by conditional simulation, providing a more complete representation of block grade uncertainty, as well as the uncertainty over multiple blocks. Simulation methods allow quantification of the uncertainty of the mineral resource prediction risks in downstream studies such as mine design, mine planning, or operational optimization studies; the risk assessment is achieved after applying transfer functions to the conditional simulation models (Dimitrakopoulos 2012; Rossi and Deutsch 2014)."

Jan 1, 2017

By Jan M. Mutmansky

Since 1973 when the first edition of the SME Mining Engineering Handbook was published, many significant changes have occurred in the US mining industry. The industry went through a fairly prosperous period immediately after 1973, but then many economic pressures came to bear on mining companies, particularly in the metal and coal branches of the industry. These pressures changed both the mining methods used and the general economics of the mining methods. As a result, the industry today is different in many ways titan it was in 1973. A general summary of some of the more important changes that have come about will be provided here as well as some assessment of the effects of these changes on the choices of mining methods. In the metal mining industry, the most significant trends were increased surface mining, the use of larger and more efficient equipment, and increased technology and automation. The primary impetus for these changes was unprecedented competition from foreign producers. In many cases, this competition came about because of the nationalization of foreign mines and the tendency for these mines to become a source of foreign exchange. Under these circumstances, the mines could be operated even though they were not profitable. As a result, domestic

Jan 1, 2008

By P J. Harper

Maximising shareholder value is a widely stated strategic goal of many mining companies. Mining projects can be capital intensive and achieving good returns is essential to encourage future investment in the industry. Despite the widely accepted importance of shareholder value, the minerals industry is often accused of providing relatively poor returns when compared to other industries. There are many recent and well publicised examples of minerals companies that have failed to deliver value to their shareholders. There are numerous business improvement initiatives employed within the mining industry to assist mine operators improve performance. Some are more effective at creating value than others. Benchmarking is one technique that is commonly used to identify performance gaps and target and prioritise opportunities for improvement. However to be effective, Benchmarking must be used appropriately and result in actions that lead to measurable operational improvement. When conducting a Benchmarking project it is important to remember that the aim should be to improve value. For this to be achieved, the strategic goals must be incorporated into the process. This paper details a structured and comprehensive approach to conducting a successful Benchmarking project. Focusing on Benchmarking as a technique for measuring and improving operational performance in underground mines, the underlying drivers of best practice in underground mining are identified.

Jan 1, 2005

Control of construction projects is the responsibility of the Project Leaders who have the authority to make decisions. Project Controls cost and scheduling systems provide the Leaders with timely information on which to base their decisions.The Client (Owner) will invest up to three per cent of the project cost on Project Controls. To ensure that this investment is effective, the Owner or Manager must have a clear understanding of the information required from the Project controls systems. If appointing a single Managing Contractor, the Owner or Manager must stipulate what is and what is not required from the Project Controls Systems. There are numerous computer programs available for scheduling and cost control and it is important to select systems which best serve the Owner's needs.

Jan 1, 1993

By Henri Fredriksson, Rami Saario, Mark Weatherseed, Juri Matinheikki

"The challenges facing the mining industry include complex ores and declining grades, together with increasing capital costs and environmental regulations. In addition, future commodity price uncertainty makes investment decisions difficult. Shorter plant lifecycles mean that new projects need shorter payback and increased net present value. With regard to solvent extraction, the introduction of an innovative modular plant design will help to address these issues. The first such modular offering is Outotec’s VSF®X modular solvent-extraction plant that uses prefabricated and transportable modules. Reuse and recyclability have underpinned the design concept. The greatest advantage of the VSF®X modular solvent-extraction plant is its relocation possibility. Additionally, it is suitable for various metals and plant capacity is adjustable through a scalable modular structure. After a dedicated plant lifecycle, the plant can be dismantled and relocated to a new site. This reuse ability offers major benefits for short-term plants, making them more feasible due to higher residual value. A net present value analysis is made for two examples, a conventional plant with no relocation possibility and a modular movable plant with extended plant life cycle, in order to evaluate the feasibility of modular plants. Results indicate that modular plant design could offer an economical solution with the additional advantage of improved overall sustainability through its life cycle. INTRODUCTION The challenges facing the mining industry include complex ores and declining grades, together with increasing capital costs and environmental regulations. In addition, future commodity price uncertainty makes investment decisions difficult. Shorter plant lifecycles mean that new projects need shorter payback and increased net present value (NPV) (Mudd, 2010; Norgate & Jahanshahi, 2010) . Awareness of sustainability issues is also rising and sustainability reporting is now a key element of many companies’ public and investor relations. Major companies are now putting more effort in this area to earn legitimacy for new projects (Mudd 2010)."

Jan 1, 2015

By Jorge Bombilla Delgado

El presente texto señala la descripción de técnicas de voladura en Cerro Verde a partir de la descripción de la geología del área mineralizada de dicho asentamiento minero. Posteriormente se describe los dos principales sistema de estructuras: uno con rumbo general noroeste -sureste y el otro sistema con rumbo noreste-suroeste, donde se produce un fracturamiento, cuya importancia radica en la ubicación y la orientación de salida que se de al disparo. Asimismo se describe los explosivos utilizados, la sensiblidad de los mismos, la preparación del ANFO, los métodos de trabajo, disparo, el diseño de perforación y las cargas explosivas.

Nov 20, 1978

By A Turns

In a survey conducted by symplexi with underground miners in Australia; 78 per cent of participants believed that ‘safety’ is all about people. If ‘safety’ is about people, then is the mining industry focusing on the wrong thing? It would be fair to say that the mining industry is heavily systems focused. Companies develop a safety management system and use this to show regulators that they comply with legislation – however, that is only half of the picture.

May 5, 2022

By Ryo Sasai, Takeshi Itakura, Haruki Imaizumi, Hideaki Itoh

"Emission of industrial wastewater containing harmful oxoanions is one of the serious problems on account of its toxicity and the environmental pollution, especially caused by boric, phosphinic, arsenic and antimonic species. In this study, we developed a novel treatment technique of such polluted-water by hydrothermal mineralization. The treatment is “Geomimetic” method for precipitating oxoanions in aqueous media as natural ore resources by using hydrothermal treatment with calcium salts mineralizer. The treatment made it possible not only to detoxify the polluted-water, but also to recover the calcium minerals such as Ca2B2O5·H2O, Ca5(AsO4)3(OH), etc. Concentration of each ion in treated-water was lower than that of effluent standard in Japan. Moreover, the residual concentration of each ion was independent of the initial concentration, but it depends only on the solubility of the formed mineral under hydrothermal condition. Therefore, the hydrothermal treatment could be recommended as one of the treatment techniques of polluted-water.IntroductionVarious oxoanions such as boron and arsenic oxo-anions have high toxicity against human health and the environment. They are important resources, however, for plating or advanced material manufacturing industries[1-3], from which the wastewater containing these oxoanions is generated every day. An appropriate treatment is often required for industrial wastewaters to attain national effluent standards of Japan (NESJ, B: 10 mg/dm3, As: 0.1 mg/dm3). On the other hand, there is no production of arsenic and boric resources in Japan, and they are expected to be recycled. Therefore, the establishment of a system for the removal and recycling of arsenic and boron from wastewaters is of global significance.Several methods to remove them from aqueous media have been already reported by using adsorption[4], electro-coagulation[5], membrane separation[6-8] and biological techniques[9]. However, these methods have the following problems because of their stability in water. (1) Removal yield is low, especially for tri-valent arsenite ion (AsIIIO3 3-) and borate ion. (2) The applicable concentration range is narrow. In addition, the used adsorbents or collected residues after treatments are sill hazardous wastes, so that they must be treated by a proper method. But, it is very difficult to convert them to recyclable resources at most industrial plants. These problems are caused by the difficulty to recover these oxoanions as stable solid precipitates with low solubility in water. The establishment of recycling system of these hazardous compounds will be one of the world-important issues, especially, in Japan, which is poor in natural resources. On the other hand, compounds that contain high arsenic concentrations and are insoluble in water, are often found in natural minerals, for example, as haidinglite (Ca(AsO3OH)·(H2O) or Johnbaumite (Ca5(AsO4)3(OH)). This fact suggests that nature has an ability to produce insoluble As-bearing minerals. Similar phenomena can be found in case of boron, antimony, etc."

Jan 1, 2008

By J. H. Tonking, O. H. Kuschke

A description is given of the general geology, structure and minerals of economic significance of the Loolekop copper orebody at Phalaborwa. The open pit mining method is described with details of drilling, blasting, loading, hauling and primary crushing operations. A brief description is given of mine planning and its relationship to the control of the mining operation.

By Richard N. Spencer

"El surgimiento de los laboratorios combinados del Banco Minero del Perú en la industria minera facilitó las investigaciones y tratamientos en la composición de los minerales. Por tal motivo, el objeto del presente texto es remarcar la función del laboratorio químico del Banco Minero del Perú, en tanto le suministre información analítica y compleja sobre el campo mineral inorgánico, asi como garantice los resultados analíticos uniformes con la más alta calidad. Asimismo la disposición de dicha entidad química, abarca las compras del Banco Minero, plantas de beneficio del Banco Minero y el control químico requerido por las nuevas unidades de los laboratorios Metalúrgico y Petrográfico que son parte integrante de este Laboratorio Central. En este punto,el laboratorio petrográfico, como fuente permanente de información básica ayuda al geólogo o metalurgista y planifica mejor la función del laboratorio central, mientras que el metalúrgico, desarrolla pruebas de molienda de minerales, flotación mecánica y no mecánica, y pruebas de concentración por gravedad. Posteriormente están las secciones de recepción, trituración y muestreo del laboratorio, las cuales se componen del departamento de trituración, departamento de muestreo y departamento de archivo, respectivamente. Finalmente, este equipo de laboratorio, cuenta con un laboratorio de Microscopia, de preparación de muestras para el examen microscópico yde ensayos especiales, que en conjunto permiten un mejor tratamiento y descripción sobre los minerales a investigar."

Jul 20, 1956

By Mark M. Petersen

As part of the addition of eight new combined cycle generating units at the Florida Power & Light Sanford Plant, 2,129 piles were to be installed. The existing plant elements were supported on driven piles, and the variation in pile lengths during previous work, as well as available subsurface information, indicated a complex stratigraphy. At the request of the owner, the designer/construction manager developed a program to evaluate the use of pressure-grouted displacement piles. A pre-design load test program in areas that represented the apparent extremes in subsurface conditions indicated that the system was feasible; however, the presence of existing features that were to be demolished later precluded the clear delineation of subsurface conditions in advance of construction. A contract was negotiated with the pile installer based on the best estimate of potential pile lengths, with modifications to pile lengths to be set based on additional exploration. A total of 52 cone penetration soundings and five load tests were performed immediately prior to and during pile installation to establish correlations between the CPT data and pile performance. Pile depths were set based on these correlations. Pile installation was completed 6 weeks ahead of schedule and 15 percent under the original budget estimate. This paper documents the evaluation of pressure-grouted displacement piles as an emerging technology, and illustrates the benefits of a close working relationship between the owner, designer, and pile contractor at a site with variable subsurface conditions.

Jan 1, 2002

By Pradip, Beena Rai

A molecular modeling study was carried out on an adsorbed oleate monolayer on the surfaces of three calcium minerals, fluorite, calcite and fluorapatite using Universal Force Field (UFF) potentials. The cleavage plane of calcite {104} was the best template for oleate monolayer adsorbed since the surface structure enabled all the calcium sites available on the surface to be occupied by oleate anions. The area occupied per chain of oleate in this well packed monolayer was computed to be 20.2 Å, which exactly matches the value calculated to be the parking area per oleate molecule for a fully packed monolayer based on strictly geometric calculations. On the other hand, the precentage of calcium sites occupied by oleate to achieve a fully packed monolayer in case of fluroite and and fluorapatite was found to be 67% and 75% respectively. The results of this theoretical study suggest that while all the three adsorption conformations, that is unidentate, bidentate and bridging type are equally likely on fluorite and fluorapatite, bridging is most likely on calcite. Interestingly, all the conformations are observed experimentally for calcite-oleate system also. The reasons for this discrepancy between the theoretical predictions and experimental observations are not clear. More work is required to resolve this discrepancy, in particular simulation studies in presence of solvent water molecules on the surface.

Jan 1, 2003

By Kevin Connor

There was little change during 1988 in the production of minerals in Burundi. The Government of Burundi, which banned all commercial mining operations in the country in 1979, lifted the ban on mining of alluvial gold deposits and started a program of small-scale artisan gold mining in October. Along with the legal mining of gold, licensed gold trading counters were established. Other mineral commodities produced were kaolin clay, lime, and peat. In compliance with the Government ban, the only mineral wealth exploited for commercial sale and export was alluvial gold. Through financial assistance from the International Bank for Reconstruction and Development (World Bank) and the United Nations Development Program (UNDP), a study to inventory the country's mineral resources continued throughout the year. As part of this study, during the year, a West German company undertook a drilling program to further outline the nickel reserves of the Musongati area in central Burundi. Results of the work as of yearend were disappointing, with only 12 million tons of ore identified with better than 2% nickel content proven. Investigations also continued during the year regarding the centrally located deposits of vanadium-bearing titaniferous magnetite. A Norwegian company contracted to prepare a prefeasibility study for developing the deposit. The British Sulphur Corp. Ltd. was nearing completion of its $1.2 million2 study of the phosphatic limestone deposit at Matongo-Bandaga at yearend. Ore reserves of about 17 million tons grading 11% phosphorus pentoxide (P2O3) had been identified. The phosphate zone overlies a carbonatite rock, which could provide the basis for a cement industry. Additional drilling was planned for 1984. Exploration for gold was underway in 19S3 in northern Burundi through UNDP funding. Several primary deposits of shallow semimassive sulfides with gold values ranging from traces to 11 grams per ton had been discovered. With assistance from the Federal Republic of Germany, bastnasite reserves of 5,400 tons, with associated high europium oxide and cerium content, were verified, and the prospects for finding

Jan 1, 1985

Jan 1, 1993

By Marcos Antonio da Cunha

A carga de laminação é um dos principais fatores que provocam o desgaste dos cilindros. Identificar quanto e como é o desgaste ocorrido durante o processo é um problema que a indústria de produtos laminados enfrenta há muitos anos, sendo motivo de muitos estudos nessa área. Esse desgaste, além de gerar custo para o fabricante, gera uma deformação no perfil no passe do laminador, fazendo com que a qualidade do produto final seja afetada. Deseja-se, com este trabalho, detectar e identificar o desgaste ocorrido nos cilindros de um laminador a quente de produtos não-planos na sequência de passe de seção redonda-oval-redonda, durante a produção, ou seja, online. Utilizando-se métodos de cálculo semi-experimentais e ferramentas baseadas em redes neurais, desenvolveu-se um sistema híbrido capaz de prever o desgaste dos canais dos cilindros. Foram realizadas inúmeras leituras dos valores de algumas das principais variáveis durante o processo de fabricação desses produtos laminados de uma grande empresa do ramo. Os resultados medidos foram analisados e foi gerada uma base de dados para a criação do modelo de previsão do desgaste nos canais, baseado em redes neurais artificiais e modelos semi-empíricos de cálculo do perfil de desgaste. O modelo foi testado na planta e os resultados foram bastante precisos.

Aug 16, 2017

By Liliana Rybarska-Rusinek, Aleksandr M. Linkov, Ewa Rejwer-Kosińska

Joined modeling of stressed state and induced seismicity is a means to join geomechanics with seismic observations. When applied to quantifying rockburst hazard, it provides, on one hand, estimations in terms of mechanics, such as stress concentration, and, on the other hand, in statistical terms of the risk analysis developed in mining seismology. The modeling became possible due to progress in computers and numerical methods. However, despite tremendous increase of computational abilities, the joined modeling is still quite time expensive. To make it available for wide use and real time simulations, there is need to reduce the time cost of its key stages: calculation of stresses, caused by mining, and simulation of seismic events, induced by these stresses. The present work aims to decrease the time cost. The stages are time costly because of the same reason, which is a very large number N (up to millions) of elements, representing rock structure, openings and flaws. This leads to immense computational complexity (roughly of order N2) of conventional accounting for pairwise interactions between the elements. The complexity may be notably reduced, when employing the fact that interactions decrease with growing distance between elements. Specifically, the fast multipole methods (FMM) avoid the complexity N2, by employing translations of far-fields from whole collections of sources. This reduces the complexity to the order 22, where p is the number of terms involved in a single translation, is the number of translations, and is the dimension of the quantity translated. Still, for conventional FMM, the complexity remains too high to routinely perform joined modeling of stresses and seismicity.

Apr 26, 2022

By Michael P. Hardy

The report described improvements and applications of the Hybrid Computer facility. Improvements implemented under U.S.B.M. Contract H0252035 included expansion of the capability to model nonlinear seam behavior, installation of a color video output display monitor, and further development of software capabilities. To demonstrate the capability of the system, firstly, the influence of nonlinear seam behavior response to the occurrence of coal mine bumps was fully investigated and secondly, the effect of improper mining sequence on bump occurrence was demonstrated. In addition, the system was applied to the analysis of a series of practical coal mine problems. Mines in three coal seams were analysed to investigate the parameters which contribute to the occurrence of coal mine bumps.

Jan 1, 1977

By Robert H. Merrill

This report summarizes the first phase of studies to determine the design and behavior of an unsupported roof in an experimental room in limestone. The selection of a roof horizon and the design of the room were results of an investigation of the geology of the formation, the physical properties of samples from the proposed roof, and calculations from the theory of gravity-loaded beams. The design of the opening, some physical properties of the roof in place, and the behavior of the roof were checked by tests in a full-scale experimental room. The room was instrumented to measure roof deflection, separations in the roof strata, and incipient failure. The dimensions of the room before instrumentation was installed were 10 by 100 feet; the room was widened in successive increments to 40 by 100 feet. Between widening operations periods up to 6 months were allowed to provide a time test of the roof spans. The results of the measurements of deflection and separations showed that the lowest 6-inch layer in the roof became detached as the room was widened. This layer was eventually removed after standing without failure for about 4 months at room dimensions of 40 by 100 feet.

Jan 1, 1957

By D. A. Trotter, G. J. Goddard

"This paper describes a method of deciding on various design parameters for a sublevel caving layout. Layout design curves are obtained from the output of a computer optimization program. The program uses mathematical relationships derived from the theory of gravity flow of material to optimize the large number of interdependent design variables which are involved.IntroductionIn the design of an efficient sublevel caving mining system, a large number of interrelated variables need to be considered. Although many papers discuss individual variables, very little exists in the literature to show how these variables interact to achieve optimum results. This can lead to trial and error in sublevel caving design, which can prove costly, particularly because sublevel caving is a mining method which requires integration with sublevels above and below. With no pillars being left, experimental stopes cannot be isolated for study. Unfortunately, the complexity of layout design and the costs associated with trial and error have caused many planning engineers to choose more tried and tested mining methods.Sublevel caving works best to extract low-value ore surrounded by incompetent rock. All phases of the mining method can be highly mechanized, allowing low operating costs and high production rates. Good safety records are achieved, as workers are always in 'good' ground and the method is regular, making it comparable to an industrial process."

Jan 1, 1981