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By Simon D. Strauss

INTRODUCTION The changes in ownership, management, and operation of the non-fuel minerals industry since the Second World War have been dramatic. World-leading enterprises have lost their identity; host countries have taken over operations from multi-national firms; marketing practices have been drastically altered - and yet the world industry is supplying minerals on a scale far greater than had been anticipated in projections made at mid-century. The world's known mineral resources have been enormously expanded, despite the doom sayers who for decades have been predicting that depletion of non-renewable resources would impose limits to growth. PALEY REPORT One can set the stage by reviewing how the minerals outlook was regarded in a thoughtful and comprehensive analysis made in the years 1950 and 1951. During the War years, President Harry Truman of the United States had come to appreciate the decisive role played by minerals resources through his chairmanship as a U.S Senator of a committee that investigated the procurement and allocation of natural resources. In 1950, in the Cold War era that resulted in actual military conflict in Korea, he appointed a prestigious five-man commission to study the problems of Materials Policy over the following quarter century. Their findings, published in five impressive volumes in early 1952, became known as the Paley report. The text was prepared by expert scientists and economists who spent 18 months assembling statistics, making projections of future demand, and interviewing leaders in industry, academia, and government. [ ] The Commission had correctly foreseen that aluminum would replace copper as the largest volume non-ferrous metal, but it had fallen short of reality by a wide margin indeed for all three materials. Even though the Commission's expectations for growth proved to be extremely understated, it had concluded its report with grave foreboding about the effect of its estimates of demand in relation to supply, as follows: "Consumption of almost all materials is expanding at compound rates and is thus pressing harder and harder against resources which, whatever else they may be doing, are not similarly expanding. This materials problem is thus not the kind of 'shortage' problem, local and transient, which in the past has found its solution in price changes which have brought supply and demand back into balance. The terms of the materials problem we face today are larger and more pervasive." With respect to some minerals, the Paley Report expressed scepticism that, in fact, supplies would be forthcoming regardless of price. Because the Paley demand forecasts understated the actual growth in demand for virtually every mineral, one could logically have expected frequent and protracted shortages in the years since 1950.

Jan 1, 1985

By Brian R. Zuckerman

The Capitol Area East End Complex is currently being constructed under contract with the State of California Department of General Services on two sites adjacent to the grounds of the California State Capitol Building in downtown Sacramento. The complex will consolidate the headquarters of the Departments of Health Services and Education, which currently occupy several facilities located throughout Sacramento. When completed in 2003, the complex will be the largest civic office project in California history, with approximately 1.5 million square feet of office space and housing nearly 6,300 state workers. The total project is being constructed on five separate blocks in downtown Sacramento, Blocks 171 through 174 and 225. Separate design/build contracts were executed for the construction on Blocks 171 through 174 and the construction on Block 225. The scope of this paper is limited to construction on Blocks 171 through 174, which comprise a square, two blocks on a side, bounded by 15th, 17th, L, and N streets, located immediately to the east of Capitol Park and the State Capitol Building, as pictured in the image shown below.

Jan 1, 2002

By Eric S. Lindquist, Charles A. Luxford

The State of Texas recently adopted a master plan to expand the existing Capitol Complex in Austin. Phase 1 of this expansion will add two new State office buildings and five levels of underground parking to the existing Complex. Additionally, a landscaped pedestrian mall will be built atop a portion of the underground parking to enhance the area as a cultural destination. Capitol Complex website: https://www.tfc-ccp.org/ Brierley Associates was selected to provide detailed design of the entire Phase 1 earth retention system for an approximately 40-65 ft (12-20 m) deep, 500,000+ yd3 (380,000+ m3) excavation through overburden soils and limestone bedrock. To facilitate overall project coordination, all design packages were required to develop Revit models, including the retention system package. With the project located in an urban setting, this 3D model also facilitated coordination of the retention system with adjacent major structures and utilities. The retention system is a combination of soil nails, soldier piling with tiebacks and rock anchors with a shotcrete facing as a substrate for the below-grade blindside waterproofing system. Due to the substantial scope of excavation, a significant number of utilities had to be routed on a temporary span over the excavation. Brierley Associates designed this utility support structure, which required extensive coordination with the excavation support and existing utilities located directly underneath the structure’s foundations. Preconstruction geotechnical work identified a fault zone that might be encountered within the excavation; however, the fault feature was found to have a more adverse location and orientation than originally anticipated. This observation required that a portion of the temporary anchors be converted to higher-capacity, corrosion-protected permanent anchors.

By M. Maleki

Variogram analysis and kriging lack robustness in the presence of outliers and data with long-tailed distributions, which often arises when estimating grades in precious metal deposits. The capping technique, consisting of truncating the data to some top-cut grade, is widely used in order to mitigate the influence of the values in the upper tail of the distribution. However, this procedure omits part of the grade variability and is likely to provoke a bias in the estimates. To avoid these issues, a recently proposed approach is to decompose the grade of interest into three components (the truncated grade, a weighted indicator above the top-cut grade, and a zero-mean residual) and jointly estimate the truncated grade and the indicator by cokriging. This approach is attractive as it provides unbiased grade estimates, allows choosing the ?optimal? top-cut value, and essentially works with truncated and indicator data, thus avoiding the use of outlying values for calculating sample variograms and performing spatial interpolation. This work presents an application of this approach to a disseminated gold deposit that has been identified through exploration drilling. The effect of using an indicator covariate is assessed through leave-one-out cross-validation, by comparing the grade estimates with the true grades and with the grade estimates obtained with the conventional capping approach, which considers only the truncated grade as the variable of interest. As a result, cokriging the truncated grade and the indicator above top-cut grade outperforms the conventional capping approach, yielding significantly more accurate estimates. A few complementary guidelines are provided for validating the model hypotheses and for the implementation of cokriging.

Jan 1, 2014

In the Broken Hill South mine tile practice of issuing to the miner a quantity of fuse and a box of caps from which he made up the "rods" required for a particular blast, has been abandoned. Instead, capping stations have been established, and the miner can now obtain, from the magazines, fuses cut to accurate lengths with the detonators attached.Various types of fuse-cutting machines and crimping devices are available, but only those used by the Broken Hill South Mine Ltd. are described in this paper.The fuse-cutting machine, designed by the engineering staff, is an electrically driven unit fitted with a gear box for the purpose of adjusting the rate at which the fuse is fed to the cutting device, thereby enabling fuses of various lengths to be accurately severed from the main coil of fuse.The machine in question is designed to cut 4, 6, and 8-ft. fuses, but no difficulty should be experienced in designing a machine to cut fuses to any required lengths.

Jan 1, 1932

By Dale E. Walker

The Captain mine came into being under the following circumstances: 1) Commonwealth Edison had need for fuel for the generation of electricity in their Chicago service area. 2) Southwestern Illinois Coal Corp. had an ample supply of coal in the Illinois No. 6 and No. 5 seams. 3) The Gulf, Mobile & Ohio R.R. had a one-line transportation system with the capability of transporting coal from the Captain mine to Commonwealth Edison. These fortuitous conditions permitted an effective three-way partner- ship to develop. Commonwealth Edison had built a new generating station at Joliet, Ill., across the Illinois River from the existing station, to supplement their power-generating capacity for the Chicago area (Fig. 1). The annual requirement of the Joliet station is approximately 4.5 million tons of coal. From large reserves of coal in the No. 6 and No. 5 seams, Southwestern Illinois Coal Corp. contracted to supply Commonwealth Edison with approximately 6 million tons annually from its Captain mine. The logical carrier was Gulf, Mobile & Ohio, whose mainline travels through this coal field and also passes by the Joliet station on its way to Chicago. This railroad has been moving Southwestern's coal from the Streamline mine for more than 30 years. The basic ingredients of timing, scheduling, moving, and handling were adopted by the three parties, the precise details being worked out jointly. To do this, each group had to know its requirements exactly. The initial schedule was drawn up and tentatively approved, with each party taking a hard look at its own requirements and commitments to make certain that the schedule could be met on a normal daily basis. With only minor changes, the final schedule was adopted, each participant feeling that it had a sufficient factor of safety to maintain steady operation. Each party agreed to help the other in time of emergency. When a delay occurs in any part of the operation, the other

Jan 1, 1969

PRESENTATION of the 1922 Washington Award to Capt. Robert W. Hunt, honorary member and twice president of the Institute, was made at the annual dinner of the Western Society of Engineers, in Chicago, on June 18, 1923, in the presence of 250 mem-bers and guests. W. L. Abbott, Chairman of the Award Commission, when delivering the presentation address, said The life of the Govern-ment of this country, as the lives of governments are usually measured, is short, barely 150 years, but meas-ured by what it has accom-plished, this country has reached a venerable age. The first 75 years of our country's existence were necessarily preparatory to the greater developments which came in the second, and that last half of our country's existence is ex-ceeded, by ten years, by the span of life of our honored guest. "Very little iron and steel were produced in this coun-try until after the birth of Robert W. Hunt. And it was not until after 1860, when as a boy of 21 he joined his fortunes with those of the Cambria Iron Works, that the iron and steel business of the country really took root. After a year or two with the Cambria Works, he left a promising position to go into the army, where he served for four years. After the close of the war he returned to the iron works and qualified himself as a metallurgical chemist.

Jan 7, 1923

By Robert J. Nothnagle, Kristen Franz Begor, Rodney W. Sutch

Recovery of contaminated groundwater in a fractured bedrock system presents some unique problems. Typically, the most common problem occurs from the inability to adequately characterize the discrete fractures through which contaminants may be migrating. Without adequate characterization, difficulties arise in properly positioning recovery wells and verifying the performance of the system. To overcome these difficulties at a site in Upstate New York, an innovative approach was developed involving the creation of an artificial fracture zone through controlled blasting to intercept contaminated groundwater flow.

Jan 1, 1988

By A. G. Belova

With the federal climate change legislation in progress, there is a need for demonstration-stage technologies aimed at providing clean energy from coal. Our research aims to experimentally illustrate the feasibility of capturing CO2 on a novel sorbent system from a gaseous stream. The gas is then released resulting in a regenerated sorbent and a pressurized stream of pure CO2 to be used for storage. The proposed sorbent is a ceramic honey-comb structured monolith coated with CaO supported on a high-surface area alumina. CaO is a natural acceptor of CO2 and our design ensures the physical stability and chemical reactivity of CaO over a large number of CO2 capture/release cycles. Furthermore, the use of the monolith ensures a uniform flow through the reactor, minimizes pressure drop across the reactor, and maximizes the surface reactive area. In this paper, we will present the results from a flow-through laboratory-scale reactor that establishes the efficiency of the proposed system to capture CO2. Future applications of the reactor include integration within the new-generation coal gasification power plants, such as IGGC, as means of providing decarbonized electricity.

Jan 1, 2010

By A. Ndibalema

Blasting is one of the primary functions in any mining operation. Despite the fact that it generally constitutes between 30% to 40% of the mining cost, blasting also affects the cost-effectiveness of down steam activities such as load and haul, safety, tyre life for haul trucks, crushing and milling. Over the past three decades, significant progress has been made in the development of new technology in an attempt to reduce costs and increase efficiencies and productivities of blasting activities. Mine to mill project concepts have paved the way for such developments. Other advancements have included sophisticated computer modelling technologies for blast design and performance analysis. There are many factors that affect the cost of blasting. These can be divided into two categories; controllable and uncontrollable. The latter includes costs related to depreciation, exchange rates and government legislation with the former category including contractor versus owner blasting costs, efficiency and productivity issues and product quality. Controllable factors have one common denominator which can determine their outcome; direct site management influence. Excavator digging rates and final floor conditions give a good measure of blasting performance, and alternatively cost effectiveness. This paper is aimed at benchmarking against a blast optimisation database, understanding the relationship between costs and identifying opportunities for improvement. Understanding the cost drivers allowed a typical cost model to be developed for the current mining operation at Geita and this was used to drive continuous improvement with emphasis on closing the information loop.

Jan 1, 2008

By D. L. Cluff

Ventilation Air Methane (VAM) is a high volume low concentration methane source. The capture or use of methane from VAM is challenging, which results in the routine discharge of methane into the atmosphere. Mitigating VAM has the benefits of providing an energy source and reducing the atmospheric Greenhouse Gas (GHG) burden. The GHG radiative forcing effect of methane is 17?23 times as potent as carbon dioxide on a 100-year time horizon. Thus, any reduction in atmospheric methane would be beneficial. The calorific value of methane is 55.5 MJ/Kg; therefore, a 100 m3/s flow with VAM concentrations from 0.1?1% can provide 3.8?38 MW of exploitable power. Strategies to mitigate VAM such as: Thermal Flow Reverse Reactors (TFRR), Catalytic Flow Reverse Reactors (CFRR), Lean Burn and Catalytic Gas Turbines, Biothermica Vamox®, Megtec VOCSIDIZER©, and Vamcat? are briefly reviewed. The review of VAM mitigation technologies reveals disadvantages such as the need to maintain a minimum internal heat capable of oxidizing the methane. This requirement uses all of the available methane up to the point of reaction sustainability and up to half at the highest methane concentration in VAM. Some systems may introduce a pressure drop to the ventilation system, which would impinge on the existing ventilation system design. These impediments necessitate the development of a more amenable technology. In the proposed system, gas turbines (GT), coupled to a combustion chamber with an external fuel supply, assist the combustion of the VAM. The combustion-chamber coupled system provides electricity, while the heat contained in the GT exhaust gases increases the temperature of the VAM, encouraging the development of a flame inside a combustion chamber. The flow from the combustion chamber streams through a primary air/fluid heat exchanger capable of producing steam of a high enough quality to generate electricity using conventional steam turbines. The residual heat after primary extraction, directed through other equipment, provides additional heat based products such as industrial scale dry air, chilling by an absorption chiller or hot water. The overall design of the system is scalable for low to high VAM flows or variations in concentrations and is capable of providing the company or community with heating, chilling, hot water, electricity or motive force as needed by the particular site or community. The Multi-generation system uses heat from three sources to provide clean efficient energy while mitigating the atmospheric emissions of methane. These sources are heat from the GT, often considered waste heat, heat from fuel injected into the igniters and heat from the VAM. The opportunity to collect carbon credits may improve the economics. In order to design a system with this capacity, a detailed analysis of the combustion characteristics of three separate flows is required. VAM is the main airflow, having the highest volumetric effect, while the GT exhaust and the additional fuel added to the hot exhaust flow of the gas turbine are lower flows, but have a higher velocity and temperature. The aim of the modeling undertaken in this work is to establish the combustion dynamics, degree of pre-heating required and the geometry essential to the design of combustion based VAM mitigation multi-generation systems.

Aug 1, 2013

By M. W. Lewis

A mine's inherent capacity is dictated by factors such as equipment, design, people, processes, and environment. Actual production may approach, but never surpass, the inherent capacity limit. The inherent capacity ceiling can only be increased through re-engineering. Autonomous haulage systems have the potential to significantly increase a mine ’s inherent and realized capacity. Realized capacity may be maximized through the optimization of soft factors such as the processes, behaviours, and organizational systems, controlling asset utilization, availability, and performance. Truck shovel dispatching systems revolutionized the utilization of mobile assets. High-precision global positioning systems (HP-GPS) are increasingly being adopted to optimize equipment performance. Real-time maintenance management systems have the potential to revolutionize equipment availability and significantly reduce cash costs. This paper explores some of the solutions available to mines to increase their inherent capacity and maximize their realized capacity.

Jan 1, 2004

By M. W. Lewis, B. Sambirsky, J. Werner

A mine’s inherent capacity is dictated by factors such as equipment, design, people, processes, and environment. Actual production may approach, but never surpass, the inherent capacity limit. The inherent capacity ceiling can only be increased through re-engineering. Autonomous haulage systems have the potential to significantly increase a mine’s inherent and realized capacity. Realized capacity may be maximized through the optimization of soft factors such as the processes, behaviours, and organizational systems, controlling asset utilization, availability, and performance. Truck shovel dispatching systems revolutionized the utilization of mobile assets. High-precision global positioning systems (HP-GPS) are increasingly being adopted to optimize equipment performance. Real-time maintenance management systems have the potential to revolutionize equipment availability and significantly reduce cash costs. This paper explores some of the solutions available to mines to increase their inherent capacity and maximize their realized capacity.

Jan 1, 2004

By Robert B. Parsons

"One of the disadvantages of the federal government's idea of ""taxation by consultation"" is that it seems to take longer to enact new legislation. The proposed new rules for taxing automobile benefits is one example. Here is a ball which has been batted around between government and the public several times and still has not come down to earth. Fasten your seatbelts, there may be more to come. IntroductionThe draft legislation released on April 13 contains the details of the government's current proposals on car expenses and benefits. They differ significantly from the last announced position. Finance Minister Wilson has indicated that the release in draft form will provide an opportunity for the Commons Standing Committee on Finance and Economic Affairs (the Blenkarn committee) and other interested persons to comment before the legislation is introduced in Parliament. Accordingly, there may yet be revisions.Notwithstanding the prospect of further changes, the proposed rules generally come into force in 1988. While taxpayers may welcome some of these changes, particularly the increase in the tax-exempt allowance, many must be frustrated that, at this late date, the rules for the current taxation year are not yet finalized."

Jan 1, 1988

By Samuel Taylor

IF I LIVE another fourteen months and am still con-nected with the coal industry, I shall then have com-pleted a half century with it. Since May, 1874, when .I first entered the bituminous workings as a miner, I think I have held almost every position connected with a mine except possibly that of mule driver, for which I was unfitted by reason of my religious upbringing. We are all agreed, at least I have not heard it contra-dicted, that there is serious over-production in the bituminous industry. This has come about in various ways and is easily explained. During the Fuel Admin-istration, I recall making an estimate of the possible output of the bituminous mines of the country provided they were given a full force of men and a full-car supply; my estimate was a little over a billion tons a year. A few months ago, the late Francis H. Peabody, of Chicago, made a practically identical estimate. If, however, both of these conditions should happen con-currently, there would very soon be no market for the coal, and many of the mines would close down. Even today, if 10 per cent. more cars were furnished, to the bituminous mines, market prices would drop very seriously.

Jan 4, 1923

By José Antonio Enríquez

El presente texto describe las características estructurales y estratigráficas de los yacimientos epitermales de baja sulfuración en el corredor estructural de San Pablo en Porculla, Cajamarca. En este sentido, el corredor se relaciona a un sistema de fallas regional que tiene rumbo general NW-SW y está segmentado por fallas transformantes de dirección NE-SW, que limitan bloques estructurales. Asimismo, sobre este corredor estructural se ubican en forma alineada una serie de yacimientos epitermales del tipo baja sulfuración. Los yacimientos están controlados por fallas de dirección NW-SE y contienen mineralización en vetas y mantos con relleno de cuarzos, calcita y baritina con importantes valores de oro y oro-plata y las estructuras menores relacionadas a las fallas transformantes. Finalmente, estos yacimientos pueden constituir un nuevo e importante objetivo de exploración por minerales de oro – plata del tipo bonanza.

Sep 12, 2005

By José Fernandes De Oliveira Ugarte

El presente texto describe los resultados de la caracterización mineralógica de muestras minerales de cobre que fueron empleados en el proceso de flotación. Para este proceso, fue necesario conocer la mineralogía de diferentes minerales de cobre de yacimientos tipo pórfido, así como sus asociaciones con los estudios mineralógicos y estudios geoestadísticos por microscopia electrónica de barrido con el sistema de energía dispersiva.

Feb 1, 2014

La caracterización del marco estructural distrital sugiere que la compresion fue inducida a partir de las fallas de rumbo Chicama-Chirimayo con una clara evidencia de vergencia hacia el noreste observado en los anticlinales, interrumpidos por fases de extension determinando bajos estructurales a lo largo de corredores tipo grabens de dirección noroeste, asociado a fallas de componente destral relacionado con emplazamiento de cuerpos subvolcanicos con mineralización de tipo pórfido de cobre-molibdeno coetaneo en 12 Ma.

May 1, 2008

By Luis Tejada

El proceso de minado en la mina Cuajone comprende dos niveles adicionales a la plataforma de minado. Sin embargo, debido a las condiciones de inestabilidad del sector, se prevee modificar la secuencia de minado para descargar la zona de deformación y crear condiciones estables de los taludes. En este sentido, el presente trabajo comprende dos partes: la primera, describe la información geomecánica de los taladros de perforación diamantina, el mapeo de celdas y los ensayos de laboratorio como caracterización del macizo rocoso y la segunda, refiere al Modelamiento Numérico a través del uso del Código Universal de los Elementos Distintos (UDEC) para el modelamiento en medios discontinuos, donde se utilizó la información topográfica, litológica, estructural, propiedades del macizo rocoso y secuencias de minado.

Sep 13, 2001

By Erick Lino

Como parte del proceso extractivo de la minería, se generan materiales de desmonte que deben ser almacenados en topografías bruptas y planas dependiendo de la capacidad de almacenamiento que requiera el proyecto. La geometría y los taludes de estas estructuras deben ser diseñados tomando en cuenta las propiedades de resistencia del desmonte de mina. Por ello, el presente texto describe la importancia de la caracterización geotécnica de este material con el objetivo de diseñar el depósito de una unidad minera en condiciones estáticas y dinámica.

Feb 1, 2017