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By Cary Hirner

The Metropolitan Water Reclamation District of Greater Chicago (District) is in the final phase of completing the Calumet System component of the Tunnel and Reservoir Plan (TARP) by bringing the Thornton Composite Reservoir online by 2014. The Thornton Composite Reservoir will provide nearly 30 billion liters (7.9 billion gallons) of additional storage for minimization of combined sewer overflows(CSO) and flooding in the Chicago metropolitan area. The project requires that the existing 6.7 m (22 ft) diameter Thorn Creek tunnel conveying overbank flood flows is re-routed and connected to the Thornton Composite Reservoir. This paper presents the components of the Thornton Composite Reservoir and specifically the detailed evaluation of a drill-blast tunnel. Other project features include an access shaft, control gate, energy dissipating structure, bulkheads, and live tunnel connection. The construction contract will be procured in late 2009.

By Walter W. Kaufman

This Bureau of Mines manual for design of surface mine haulage roads covers such aspects of haulage road design as road alinement (both vertical and horizontal), construction materials, cross slope, and drainage provisions. Traffic control and design of proper lane widths to promote safe vehicle movement are included, as are suggested criteria for road and vehicle maintenance and for runaway-vehicle safety provisions. The aim of this publication is to provide those involved with surface mine haulage road design with a complete manual of recommended practices that, if implemented, will promote safer, more efficient haulage routes.

Jan 1, 1977

By L. E. Djingheuzian

IN 1953, Lewis (1) published an article which brought forth a great amount of discussion by grinding engineers. In his contribution to discussion the present writer (2) suggested that, for the most efficient performance of a ball mill, there must be a .definite relationship between Cn, per cent critical speed, and V p, per cent mill volume occupied by the ball charge. Later, he ( 3) was able to publish some grinding data from Wright-Hargreaves milly which appeared to bear out this contention. It is with this view to establishing a fundamental relationship between Cn and Vp that the idea of this Forum was conceived. Accordingly, a questionnaire was prepared and copies of it were mailed to over eighty Canadian mill operators. This questionnaire did not include a question on dilution on the assumption that each mill operator was using the most efficient dilution for his operation, nor was a question on efficiency of classification included since it was thought that the inclusion of efficiency of dassification in the questionnaire at this preliminary stage might render the forum discussion,. while everybody was trying to find his bearings, too unwieldy. However, it is evident that, as discussions develop, this forum will have to define a uniform method for establishing most efficient classification in grinding circuits

Jan 1, 1957

By Joseph T. Singewald

The possible value of the red hematite iron ore of the southern Appalachian States, if some practicable method of concentrating it could be devised, has long been recognized. The ore is very low grade, and although in enormous quantities, particularly in the States of Alabama, Tennessee, and Georgia, is only at a few points rich enough to work, and even the best of it ranks among the lowest grade iron ores being mined in the United States. A cheap method of beneficiating this ore would make enormous quantities available and vastly increase the iron-ore resources of the country. However, this low-grade ore in effect constitutes a potential iron reserve, and as long as ample quantities of ore can be obtained elsewhere the question of its utilization does not demand immediate notice. Where these ores are in part of workable grade, however, a problem of more immediate importance arises which, from considerations of economy and prevention of waste in their mining, ought to be solved or, at least, attacked as quickly as possible. Where these ores are being worked they are usually intimately associated with lower-grade material that in mining is left behind. The difficulty and expense of going into ground broken by old workings makes the recovery of this lower-grade ore practically impossible and it is lost forever. Success in concentrating the red ores, therefore, would save material that is now being irretrievably lost. The successful large-scale concentration of law-grade ore in the last few years on the Lake Superior iron ranges should encourage the attack of similar problems in the Birmingham district.

Jan 1, 1917

By Alexander May

The Bureau of Mines, in cooperation with the Florida phosphate mining industry, investigated the dewatering of waste phosphatic slimes. Part of this investigation was to determine the electrophoretic mobilities and cation exchange capacities of the slimes. The mobilities and exchange capacities are reported for samples of slimes taken from 15 plants operating in the Florida land-pebble phosphate district that includes Polk,Hillsborough, Manatee, Hardee, and DeSoto Counties. The electrophoretic mobilities determined were all negative, ranging from -0.24 to -1.93 (micrometers per second) per (volt per centimeter). Also reported are frequency distributions of electrophoretic mobilities, electrophoretic mobilities of slime diluted with distilled water and electrophoretic mobilities of sand-slime mixtures. The cation exchange capacities ranged from 17 to 45 milliequivalents per 100 grams of slime solids.

Jan 1, 1975

Gold was determined directly in eight different mill cyanide solutions, by atomic absorption spectroscopy in an acetylene-air flame. Some of the mill solutions were diluted with water to bring them into the most sensitive absorption region (5-50 p.p.m. Au) whereas those solutions with very low gold content «2 p.p.m.) were concentrated by evaporation.Calcium was complexed with ethylene diamine tetra-acetic acid (EDTA) to avoid the undesirable effect of a precipitate on atomization.When added to standard gold solutions, EDTA had no effect on absorption, nor did any of the impurities common in mill cyanide solutions.Known amounts of gold, ranging from 2 to 30 p.p.m., were added to mill solution'aliquots and recovered to within 100 ± 2·5 per cent. For duplicate determinations under normal worKing conditions, standard deviation was 1·32 p.p.m.Excellent agreement was found between atomic absorption gold values and accurate fire assay values.INTRODUCTIONAtomic absorption spectroscopy has been shown to offer a rapid and accurate method for the determination of trace amounts of a number of metal ions. In the field of primary metallurgy atomic adsorption has been used for routine determinations of lead, copper, silver, zinc, cadmium and iron in a variety of raw materials and intermediate products.The scope of atomic absorption spectroscopy was reviewed recently by Willis (1963).The noble metals silver, gold, platinum, rhodium and palladium were determined by atomic absorption from chloride solutions by Lockyer ·and Hames (1959). In their determination of gold down to 1 p.p.m., they found no interference from the noble metals, nor from considerable excess...

Jan 1, 1964

By A Bouazza, J Kodikara

In this study, 23 samples of leached ash (LA) were collected from an ash pond at Loy Yang Power Station and geotechnically characterised. The samples were collected at various depths and locations within the ash pond on two separate occasions in order to account for the full variability. The LA within the ash pond at Loy Yang Power Station (LYPS) was found to vary in texture from silt to sand, depending on the location from where the sample was collected. Samples collected near the ash pond inlet discharge point, for instance, contained more than 50 per cent sand sized particles and were subsequently classified under the Unified Soil Classification System (USCS) as silty sand (SM). Further downstream of the inlet discharge, the LA became progressively finer and was classified accordingly as elastic silt (MH) when the sand content became less than 50 per cent. Basic geotechnical testing revealed that the LA from Loy Yang Power Station was generally acceptable as a landfill cover material. The permeability of LA, however, was generally too high for prescriptive covers, (ie resistive covers that generally rely on the impervious nature of the material to control percolation). Alternative covers, generally rely on the store/release function of a capillary or monolithic barrier to prevent percolation into the landfill. Subsequently, a material that can maintain a high water storage capacity while at the same time, readily allow infiltration and evapotranspiration is required for an alternative cover. Sandy silt and silty sand are optimal soils for alternative covers, as they do not yield water to gravity forces, but do give up most of the water in their pores when subjected to high-matric suction (Kavazanjian, 2001). The effectiveness of alternative covers is ultimately assessed using computer models, such as UNSAT-H and HYDRUS-2D, to rigorously perform water balance calculations. Prior to using a computer model to determine the highest possible percolation in the worst climatic conditions, it is necessary to select the most appropriate materials. This paper suggests a method to screen available materials for use as an alternative cover material on the basis of the soil water characteristic curve (SWCC).

Jan 1, 2003

By S. I. Angadi, C. Eswaraiah, Sunil Kumar Tripathy, T. Santosh, Nilima Dash

Banded hematite quartzite (BHQ) and banded hematite jasper (BHJ) ores represent a promising potential iron ore resource in the near future. The hematite and quartz in BHQ and the hematite and jasper in BHJ are closely related and require fine grinding for the liberation of hematite phases. The present study investigates the mineralogical features and comminution properties of BHQ and BHJ ores. In the BHQ ore, it is observed that thick bands of hematite have fine inclusions of silicate minerals, whereas silica bands have few grains of iron-bearing minerals. The hematite and quartz minerals in the iron and silicate bands of the BHJ ore appear to be more intricately associated and complex in nature, presenting difficulties for liberation. Bond work index studies were carried out for the BHQ and BHJ ores with different product fineness in order to evaluate the energy requirements in fine grinding. A higher Bond work index value was found for the BHJ ore (15.4 kWh/ton) than for the BHQ ore (12.4 kWh/ton). A decrease in the product particle size was associated with an increase in the work index value. Single-particle breakage experiments were designed by varying feed particle size and input energy. The specific energy consumption for the BHJ ore was higher than that for the BHQ ore. The comminution parameters showed that the BHJ ore is harder to grind than the BHQ ore, which may be due to the mineral composition and association of hematite phases with the silicates.

By E. C. Grunsky, B. W. Smee

"The development of low-cost, rapid multielement analytical techniques has generated large geochemical databases in many exploration programs. When a sampling program consists of several thousand samples, the resulting data matrix is enormous and effective interpretation using all of the elements individually becomes burdensome. However, the application of multivariate statistical techniques can extract geochemical patterns related to the underlying geology, weathering, alteration and mineralization. Imaging the results over topography enhances the interpretation of these patterns. Examples of this approach are shown from mineral exploration programs in Canada and Mexico. IntroductionThere has been a dramatic change in the effectiveness of using geochemical survey data in the past ten years. This is mostly due to:• lower cost of geochemical analysis;• lower detection limits;• new methods of multi-element analysis;• a marked decrease in the turnaround time;and• the intelligent use of computers in presenting geochemical data.Geochemical surveys commonly have two objectives: locating abnormal concentrations of ore-forming or pathfinder elements and characterizing the underlying host lithologies. Geochemical surveys often employ a wide range of sample media that may typically include whole rock lithogeochemistry, various soil horizons, till and basal till sampling, stream sediments, lake sediments, and various forms of weathered regolith. Each of these sample media will exhibit a unique element distribution that must be factored in the interpretation phase of a geochemical survey study. This can become a cumbersome process if univariate data handling methods are employed."

Jan 1, 2003

By L. Vollert

In-situ recovery of metals is presently experiencing a revival not seen since early applications in amenable copper oxide deposits, uranium and generally applications where neither, porosity and permeability, nor process chemistry have been prohibitively difficult. With ever decreasing grades in current mining operations or Greenfields projects and ever increasing capital and operating costs, in-situ recovery is looked to as the processing option that will both unlock these deposits as well as potentially derive revenue from mineralised waste remaining in the ground once traditional mining and processing methods become uneconomical. In-situ recovery is also being looked to as a mining method that minimises the environmental impact sustained in the application of traditional energy and water intensive mining and processing operations where millions of tonnes of ore are mined from the earth, processed on surface and then disposed of in both waste dumps and tailings facilities. The key challenge facing companies like Newcrest is that these low-grade deposits or remnant mines are generally hard rock applications that require costly methods to liberate the valuable minerals. A further challenge includes identifying suitable chemistries that both facilitate the economic recovery of gold and copper and that may be considered environmentally acceptable. This paper presents a desktop study whereby the issues of access creation and chemical extraction are discussed and evaluated with a view to driving future research in the area and unlocking this application as a real processing option. INTRODUCTION Mining companies are increasingly challenged by low grade, deep and complex ore deposits which are no longer economically exploitable by current methods. The large footprint of current open pit operations can present obstacles for permitting and social acceptance. For these reasons in-situ recovery (ISR) technologies are receiving renewed attention as a technology which could be used to exploit these more complex deposits economically and with less environmental impact. The environmental impact may be further reduced if emphasis is placed on use of renewable energy sources rather than traditional grid power, gas turbine or diesel generators are employed to drive the operation. A potential renewable energy driven ISR mine of the future is shown in Figure 1.

Jan 1, 2019

By E. Pezennec

A voluntary comprehensive environmental Risk Assessment was launched at the end of 2004 by the International Chromium Development Association. The completion is scheduled for mid 2006.EURAS, a leading environmental consultancy, was commissioned for this project, as this firm wrote in particular the Metals Environmental Risk Assessment Guidelines, the reference document for the metals and metals compounds, in particular for the forthcoming European new Chemical Policy and the Globally Harmonized System for the Classification and Labelling of Chemicals (GHS). This project follows a stepwise approach, comprising 3 distinct steps: - Initial Risk Assessment: compilation, evaluation of the existing effects and exposure data for chromium III compounds and chromium metal. This information will be used for the compilation of an initial Risk Assessment Report. - Data gap analysis: which type of additional effects data should be collected and/or which exposure scenarios merit a more detailed targeted risk assessment? Recommendations and/or suggestions for further research will be formulated. - Road map: prioritization and ranking of the different proposed research programs. The presentation will mainly focus on the results and recommendations of the initial environmental Risk Assessment from an International perspective and not from an European point of view. - Hazard assessment ? definition of the Predicted Non effect Concentration (PNEC) for each environmental compartment (water, sediment, soil) - Exposure assessment ? definition of the Predicted Environmental Concentrations (PEC) for each environ-mental compartment - Comparison of the local PEC with PNEC for the chromium III compounds and chromium metal EU industry sectors covered in the project: mining of chromite, metallurgical production of chromium metal, chromium containing alloys production, production of trivalent chromium chemicals and the main applications (pigments, leather tanning, etc..). The current status on the environmental Classification and Ranking for chromium III compounds, Chromium metal and its alloys in the GHS will also be covered.

Jan 1, 2007

By David J. Kusler

This study is an appraisal of the feasibility of recovery and the possible chemical and physical uses of the limestone from the Greenbrier Formation in western West Virginia. Data on minability, occurrence, quality, and markets were obtained from published and unpublished sources and by a limited mail survey combined with personal contacts. The estimated costs of recovery by deep mining techniques are considerably higher than competitive surface and shallow subsurface operations. Compositional in formation available for this study was limited but indicated the suitability of the limestone for most physical uses and some chemical process uses in appraisal of the uses and demand reveals that immediate markets may be difficult to establish, but for some uses long-term prospects may be encouraging, especially if the quality of limestone would be suitable for lime manufacture or use as metallurgical fluxstone.

Jan 1, 1968

Background Chronology 2008 Positions May 8, 2010 Summit Going Forward Say one thing and do another ??Genuine passion to see our customers succeed?, ?A passion for exceeding our customer?s expectations? Self serving actions to gain competitive advantage at the expense of the customer No single supplier or technology can manage the overall mine and its integrated operation - April 2005: Informal meeting at Toronto CIM 2004 -Unanimous interest - July 2005: Formal Calgary Meeting, developed: - Scope and vision statement , - OEM/OTM communication plan, - industry communication plan - Aug?Nov 2005: Aligned with SMART - Nov 2005?May 2006: Direct OEM, OTM communication - May ?Sept 2006: Developed baseline standards - Sept -April 2007: Developed SMART document - Sept 2007: Document distribution and request OEM OTM response - Jan ?May 2008: Acquired OEM OTM feedback and positions May 2008: Results presented to SMART and discussions on next steps

May 1, 2010

By G. T. Daware, M. J. Chaddha, S. P. Masurkar, P. G. Bhukte, A. Agnihotri

JNARDDC has evaluated bauxite deposits of India from the geo-technological point of view. During the evaluation studies, it was observed that bauxite deposits are associated with saprolite resources. During bauxite mining, various low-grade materials such as saprolite, laterite and low-grade bauxite are generated. These materials typically have low-alumina, high-iron oxide and high-silica content. Owing to their inferior quality, these materials cannot be used for alumina production and hence remain unutilized at the mine site. For the present study, the saprolite samples were collected from the Western Ghats bauxite deposits in India. The sintering studies were conducted on saprolite granules using a variety of parameters. The sintered granules were characterized, and their properties determined. The test results showed that bulk density, apparent density, porosity and refractoriness (PCE 1645–1659 °C) of the aggregates were within the range of refractory specifications. The feasibility tests carried out at the refractory industry indicated that the developed aggregates are suitable as refractory material and can substitute for calcined clay. Currently, high-purity clay resources used in the refractory industry are limited and fast exhausting; therefore, the industry is likely to face an acute shortage of raw materials, which will become more critical in the future. Therefore the sintered granules (aggregates) developed from saprolite, which is a mining waste, provide a low-cost, eco-friendly solution for the fast-exhausting resources of the high-purity clays. The developed process may change the Indian bauxite mining scenario because saprolite may substitute as a potential raw material for the refractory industry.

Apr 12, 2021

By Robert H. Merrill

Several investigators have obtained solutions for the concentration of stress around circular, ovaloidal, elliptical, and rectangular holes in an elastic, isotropic, semiinfinite plate subjected to uniaxial and biaxial stress. These solutions are used to evaluate the changes in stress around openings immediately under the undercut normally used in conventional block caving operations. The evaluations are based on the assumption that a horizontal undercut removes most of the vertical component of a biaxial stress field. The location and magnitude of the significant changes in stress concentration around the opening are computed. Conditions under which the assumptions used in the evaluations may or may not be consistent with conditions around block caving mines are discussed, and examples of preferred opening shapes for a biaxial (hydrostatic) stress field are shown. This report is a summary of one phase of an investigation to establish design methods for the size and shape of mine openings used in block caving mining methods .

Jan 1, 1962

THERE is at least one concrete indication that Soviet Russia's two most important iron ore producing centers are seriously depleted. While keeping in mind Russia's penchant for reverse propaganda, one piece of evidence indicates that Magnitugorsk in the southern Urals and Krivoi Rog in the Ukraine have been mined to a point where lower grade ores are being recovered. An article in Pravda, Soviet newspaper, by I. P. Bardin. a Russian metallurgist, says that ore presently mined must undergo an expensive enriching cycle before it can be used in blast furnaces. Com- pounding Russian metallurgical troubles is the low quality of coking coals. High ash and sulphur content typifies the coal Badin talks about. Coal from the Ukraine, Eastern Siberia, Kazakhstan, and the Far East requires extensive treatment before it can be used, according to the article in Pravda.

Jan 7, 1953

By Cabrera M. Manuel C

A fines de 1980, la empresa Minero Perú construyó una operación piloto de monitores y planta de lavado con una capacidad de 1,500 m3/día, incrementando la producción de oro a un 80%. En este sentido, el presente texto señala la producción de oro de esta minera peruana, utilizando dichas herramientas mencionadas. Para ello, se describe la geología, minado, características del monitor seleccionado, características de la bomba de alta presión, metalurgia y las plantas de lavado.

Oct 14, 1980

By Leandro Moosher

A crescente geração e disposição de resíduos sólidos tornou-se preocupante, para tanto busca-se um fim adequado aos mesmos. Este trabalho objetivou avaliar a viabilidade técnica, ambiental e financeira do uso das areias fenólica e verde usadas de fundição como co-produto em substituição parcial ao agregado miúdo areia natural de rio na fabricação de blocos de concreto para pavimentação. Produziu-se 3 traços com 25% e 50% de substituição da areia natural por uma composição de areia de fundição com os mesmos equipamentos e parâmetros comerciais e obteve-se resultados satisfatórios, como a resistência à compressão através do traço rico em consumo de cimento e com 25% de substituição da areia natural pelo co-produto atingindo 37,2 MPa, cerca de 6% acima do mínimo requerido pela NBR 9780. Já na avaliação ambiental esses blocos foram classificados como Resíduo Classe II-A Não Inerte e a análise de viabilidade financeira mostrou custo 1% menor que o bloco convencional.

Aug 8, 2018

By A. W. Hall

A nuclear method was developed for continuously and automatically deter-mining the moisture content of coal flowing through a bin. Fast neutrons from a 1 curie americium-beryllium source penetrate the coal, are thermalized (slowed down) by hydrogen in the moisture, and are counted by a thermal neutron detector. The difference between the number of these thermal neutrons and those thermalized by dry coal (in a reference drum) is a measure of the moisture content of the coal. A materials handling system was developed and in tests at a commercial coal preparation plant, moisture in coal was monitored continuously within 0.2 percent of values determined by conventional means. The meter responded rapidly to change in moisture content, making it adaptable to automatic process control, and was operated for 1 year without malfunction or recalibration. Shielding of the source by the coal kept the neutron flux level at the bin wall less than 1 milliroentgen per hour, a safe level for personnel.

Jan 1, 1973

By Reda M. Bakeer

"An approach slab is the roadway segment that immediately follows a bridge intended to provide a smooth transition between the two elements. Some approach slabs have developed rough rideability with time due to differential settlement between the roadway embankment and the bridge. Soils in south Louisiana are generally poor and highly compressible and, therefore, pile-supported approach slabs were occasionally used. Timber piles of variable lengths are driven into the soft soils where no appreciable toe support exists. This resulted in the soils both supporting loads through shaft resistance and yet experiencing long-term consolidation settlement. Field testing and review of the records of over 120 approach slabs constructed in south Louisiana yielded the conclusion that their performance is primarily governed by negative skin friction (downdrag) imposed on the relatively short timber piles. A software (TU-DRAG) was developed to evaluate the deflection profile of a pile-supported approach slab based on its geometry and conditions of the underlying soils. It evaluates the effect of dragload considering the number and spacing of the piles at each transverse row and their variable lengths along the approach slab. TU-DRAG was utilized in the design of two transportation related projects which have been in service for more than 10 years.INTRODUCTIONThe problem of differential settlement at bridge approaches or “the bump at the bridge” has been recognized for many years. Research studies (1986, 1989, 1997, 2009 and 2013) by the Transportation Research Board (TRB) and the Federal Highway Administration (FHWA) provided comprehensive evaluations of the performance of bridge approach slabs by assessing their field conditions and construction and maintenance records. Various states have also performed their own studies to investigate the performance of bridge approach slabs. The studies considered various types of structures including soil- and pile-supported approach slabs, integral bridge abutments and open-end abutments. Recommendations were provided for the design of new structures and for maintaining and repairing existing structures. Guidelines were offered regarding tolerable movements of bridges and their foundations based on measurements of vertical and horizontal movements of 580 bridges Moulton (1986). Vertical and horizontal movements greater than 102 mm (4 inches) and 51 mm (2 inches), respectively, were considered intolerable. Tolerable limits for angular distortion (differential settlement to span length) were suggested to be 1/250 and 1/200 for continuous and simple spans, respectively. It was reported that a differential settlement greater than 13 mm (0.5 inch) at the bridge interface would be sufficient to constitute a “bump” requiring mitigation."

Jan 1, 2017