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By Susanne Hering, Brent Kirby, Charles D. Litton, Tracy Allen, Kirk R. Smith, Rufus Edwards

In developing countries, high levels of particle pollution from the use of coal and biomass fuels for household cooking and heating are a major cause of ill health and premature mortality. The cost and complexity of existing monitoring equipment, combined with the need to sample many locations, make routine quantification of household particle pollution levels difficult. Recent advances in technology, however, have enabled the development of a small, portable, data-logging particle monitor modified from commercial smoke alarm technology that can meet the needs of surveys in the developing world at reasonable cost. Laboratory comparisons of a prototype particle monitor developed at the University of California at Berkeley (UCB) with gravimetric filters, a tapered element oscillating microbalance, and a TSI DustTrak to quantify the UCB particle monitor response as a function of both concentration and particle size and to examine sensor response in relation to changes in temperature, relative humidity, and elevation are presented here. UCB particle monitors showed good linearity in response to different concentrations of laboratory-generated oleic acid aerosols with a coarse (mass median diameter, 2.1 µm) and fine (mass median diameter, 0.27-0.42 µm) size distributions (average r2 = 0.997 ± 0.005). The photoelectric and ionization chamber showed a wide range of responses based on particle size and, thus, require calibration with the aerosol of interest. The ionization chamber was five times more sensitive to fine rather than coarse particles, whereas the photoelectric chamber was five times more sensitive to coarse than fine. The ratio of the response between the two sensors has the potential for mass calibration of individual data points based on estimated parameters of the size distribution. The results demonstrate the significant potential of this monitor, which will facilitate the evaluation of interventions (improved fuels, stoves, and ventilation) on indoor air pollution levels and research on the impacts of indoor particle levels on health in developing countries.

A systematic study of groundwater conditions at eight underground mine sites exhibiting a wide range of groundwater qualities throughout Australia has been completed at the WA School of Mines. This has resulted in a new corrosivity classification for groundwater driven corrosion processes for cement grouted cable strand used in the Australian underground mining industry. The new corrosivity classification is simple to use and corrosion rates may be predicted from readily obtained in situ measurements of groundwater dissolved oxygen.

Jan 1, 2008

By Lee Ann Gardner

This U.S. Bureau of Mines publication presents a case study of the processes used in permitting the Nome Offshore Placer Project, a gold mining project offshore Nome, Alaska which operated from 1985 through 1990. The mining project, developed by Western Gold Exploration and Mining Company, Limited Partnership (WestGold), used the BIMA, which was at the time the largest bucketline mining vessel in the world, to dredge gold from the ocean floor. This case study reviews the permitting process from the regulators' and industry's perspectives, as well as characterizing the efficiencies and inefficiencies associated with this case. The Federal, State and local laws applicable to the Nome Offshore Placer Project are identified, agency jurisdiction and interagency relationships are explored, and the chronology of the permitting process is examined. The regulatory authorities for both environmental monitoring and post-mining monitoring are delineated. Significant milestones affecting the project and required regulatory submittals are also included. The case study of the Nome Offshore Placer Project is detailed with respect to agency involvement and coordination, approaches to permitting from both the regulators' and developer's perspective, environmental issues, and permit stipulations which were unique to the project. The advantages and disadvantages of these topics are discussed.

Jan 1, 1992

The term geochemistry - chcmbtry' of the earth - is almost limitless in its implied subject, but of recent years a major trend of research in this field has been towards economic application in the search for mineral deposits, and in particular for those of some ofthe less common elements for which a demand now exists.Geochemistry is in a state of slow transition from a purely descriptive subject to a fundamental science concerned with the relationships that exist between the distribution of the elements in the earth's crust and the physical characteristics of the atoms of those elements. The progress achieved promises a set of basic principles which will relate the atomic characteristics of an element to the physico-chemical conditions that make for its dispersion or concentration. This means that, given a geological map of an areasufficiently detailed for the physico-chemical conditions existing in past geological eras to be deduced, there is the possibility that the relative distribution throughout that area of any element present, and its likely mode of occurrence, could be predicted from a consideration of its atomic characteristics.Since the atomic characteristics of the elements are becoming increasingly well defined by physical research, the attainment of this ideal of prediction depends upon:(a) the strengthening of geochemical theory; and(b) the development of petrological and mineralogical methods of assessing the conditions of temperature and pressure prevailing in geological formations at various stages in their history.The other prime requirement is a d.etailed geological map - a requirement that is all too often lacking.The fact that there has been very little "geochemical approach" to problems of economic geology in Australia should not be taken to mean that there is little point in trying to develop such an approach here in as active and as rigidly scientific a manner as possible. The degree of success that has attended the attempts so far made, to which reference is made below, suggests the reverse, particularly in view of the relatively slight cost involved if the investigations were properly organised on a centralised basis. There are three aspects of geochemistry that are directly applicable to the search for economic minerals.(a) The classic technique of the prospector can be made more sensitive and reliable by the use of modern equipment coupled with the application of geochemical theory to geological and structural data. The case of the rare alkali elements (see below) is givenhere as an illustration of the way in which the distribution of elements can be predicted from the first principles of geochemistry, thereby replacing the prospector's dependence on his "sixth sense" that enabled him to suggest that a certain area of formation was"favourable" for the occurrence of a certain type of mineral deposit.At its best, this sixth sense amounted to an almost subconscious correlation of all relevant associations and typical occurrences of the particular mineral experienced by the prospector during his...

Jan 1, 1950

By R. A. Wattenbarger, H. J. Ramey

The trend in gas well testing has been to rely more on the early-time flow data of drawdown and buildup tests than on stabilized flow tests. The stabilized testing methods often are not adequate for complicated modern gas reservoirs because many of these reservoirs have extremely low permeabilities and the transient flow period of a well test can last for days or weeks. It has become common to augment the flow capacity of gas wells by hydraulically fracturing their producing formations. In deep reservoirs the induced fractures are generally vertical and tend to follow a single plane of weakness. The presence of a vertical fracture at the wellbore complicates the transient flow behavior of a low permeability gas well. The flow is further complicated when turbulence occurs near the wellbore. Russell and Truittl published transient drawdown solutions for vertically-fractured liquid wells. They developed methods of drawdown and buildup testing utilizing these solutions, which were based on numerical simulation. Clark2 applied the basic Russell-Truitt solutions to analyze fractured water injection wells by falloff tests. Field examples were given to substantiate the method of analysis. The Russell-Truitt solutions and well testing methods can be extended to gas well flow. Millheim and Cichowicz3 presented the drawdown equations for *Now with Scientific Software Corp., Denver. ideal gas flow, including the effects of formation damage and turbulence. Two actual field cases were presented, both of which exhibited extensive fractures and turbulent flow. For the pressure range of these well tests, the use of ideal gas equations was acceptable. These field cases were significant in being the first published data showing the occurrence of turbulence in fractured gas wells. We, also, observed such cases in practice. Our purpose here is to extend the theory of fractured gas well testing to the flow of real gases. To determine the effects of wellbore storage and turbulence on well test interpretation, we developed a finite-difference model to simulate well test conditions. Since gas wells usually are widely spaced and have high compressibility, the emphasis has been put on the early transient behavior before the effects of the outer boundary are noticeable at the wellbore. The Mathematical Model The geometry of our mathematical model is similar to that used by Prats.4 The well is centered in a circular uniform reservoir. A vertical fracture of infinite flow capacity penetrates the formation and passes through the wellbore. The wellbore itself is not important. Fig. 1 shows a sketch of the problem. Fig. 2 shows the idealized model. The equation for the flow of real gas in a porous medium with uniform porosity, permeability and thickness is5-7

Jan 1, 1970

By Å. Kruukka, H. F. Broicher

The iron ores of the Kiruna mine in Sweden are of exceptional quality except for the phosphorus content in certain zones of the orebody. The prevention of mixing ores high in phosphorus with those low in phosphorus has always been of significant economic importance. The ongoing introduction of tele-mining and automatic haulage by LHDs requires new means in the field of quality control underground, as the experienced miner as well as the underground laboratory assistant no longer are involved in the process. As of 1998, LKAB has been testing prototypes of LIF (laser-induced fluorescence) analyzers for non-contact and real-time measurement of the phosphorus content of ore being transported by LHDs from the stopes to the respective ore pass assigned to a certain ore quality. The principles of the analysis of laser-induced fluorescence, the different test phases and results are described and conclusions made. With bulk sorting of ore underground, the mining engineer supports the efforts of the metallurgist in the processing plant.

Jan 1, 2002

By Henry P. Chandler

[Diamond, because of its extreme hardness and abrasion resistance, has an important function in precision engineering and automation. With the increasing; requirements of modern production for fine tolerances, interchange-ability, and speed, it has become even more important. In spite of the supply of other abrasive and hard materials and of ultrasonic, electrospark rued other substitute grinding, methods, world industry seams likely to absorb large quantities of diamond for industrial purposes. An increasing part of the world's needs will be supplied by manufactured diamond, which was introduced commercially by General Electric Co. in 1957. Use of diamond for glass cutting roes bark several centuries, mid diamond drilling of rock became important to the mining industry M the 1870's. Today, diamond drilling is the most extensively used method of exploring the world's ore reserves; diamond drills two also used to determined the nature of bedrock below the foundations of buildings, dams, and bridges. Diamond drill bits are now used extensively in the petroleum industry, and replacement or steel rock bits with diamond drill bits in hard rock formations has affected substantial savings.]

Jan 1, 1964

By Henry P. Chandler

[Diamond, because of its extreme hardness and abrasion resistance, has an important function in precision engineering and automation. With the increasing; requirements of modern production for fine tolerances, interchangeability, and speed, it has become even hors, important in spite of the supply of other abrasive and hard materials and of ultrasonic, electrospspark rued other substitute grinding methods world industry seems likely to absorb large quantities of diamond for industrial purposes. An increasing part of the world's needs will be supplied by manufactured diamond, which was introduced commercially by General Electric Co. in 1957. Use of diamond for glass cutting goes bark several centuries, mid diamond drilling of rock became important to the mining industry M the 1870's. Today, diamond drilling is the most extensively used method of exploring the world's ore reserves; diamond drills two also used to determine the nature of bedrock below the foundations of buildings, dams, and bridges. Diamond drill bits are now used extensively in the petroleum industry, and replacement or steel rock bits with diamond drill bits in hard rock formations has effected substantial savings.]

Jan 1, 1964

By Per-Anders Persson

This chapter deals with the concepts ofshock waves aud detonation waves together, because a detonation wave is really a shock wave, supported by the explosive reaction that the shock wave ignites and propagates as it travels through the explosive material. In the context of rock blasting, furthermore, there is justification for treating shock waves and detonation waves together, because the mechanical effect of the detonation in an explosive in a drillhole in rock is propagated and its effects are spread throughout the surrounding rock by means of a shock wave The overall performance of an explosive in rock blasting or any other application is of course dependent on how much thermal energy is released in the chemical reaction that occurs when the material detonates, and on how much useful mrc!~amcal work the reaction products can do as they expand. A major portion of this chapter deals with the prediction and measurement of explosive performance, a subject which is now still in a process of rapid development.

Jan 1, 1994

By T. Robyn

The Bolivar Cu-Zn skarn deposit in the Piedras Verdes mining district of Chihuahua is one of many base and precious metal deposits in the north-northwest trending Sierra Madre Belt extending across the states of Chihuahua, Durango and Sonora in northwestern Mexico. The information presented here is drawn from two papers on the Bolivar property1,4 plus new information. Historical mining and exploration for polymetallic Cu-Zn-Pb-Ag-Au deposits in the Sierra Madre Belt dates to Spanish Colonial days. Access to the Bolivar Property (Figure 1) is by paved road (approximately 305 km southwest from Chihuahua) and approximately 80 km by all-season gravel roads to the villages of Cieneguita (population ~1,000) and Piedras Verdes (population ~500) adjacent to the property. [ ] The Bolivar property comprises an old Cu-Zn producer (the Bolivar Mine), exploration concessions adjacent to the Bolivar Mine, and a new camp at the mine that supports mining, exploration and maintenance. From 1980 to 2000, former operators extracted approximately 300,000 tonnes of ore that was hand sorted to an average grade of 5-6% Cu and 25-30% Zn. From 2005-2010, Dia Bras produced from the mine just over 600,000 tonnes at an average grade of 1.7% Cu and 8.6% Zn. Dia Bras transported mineralized rock 275 km by truck and rail to its Malpaso mill, located about 30 km west of Cuauhtémoc in central Chihuahua, from 2005 until October 2011 when the new Piedras Verde mill was commissioned only 5 km from the mine. (Note: the Company cannot use the term ?ore? because it has never completed a feasibility study.)

Jan 1, 2012

By Pasi Korkeakoski

There are about 400 multi-storey buildings founded on wooden piles in the city centre of Turku in Finland. Soil conditions are variable from hard rock to very soft clay. Due to the soil conditions and ground water lowering there are basically four different types of underpinning projects. Under dimensioned cohesion piles in a deep clay layer, decaying cohesion piles, a combination of these two reasons and decaying end bearing piles in a thin clay layer area. Many different execution methods have been used such as impact driving, jacking and drilling and combinations of these.

Jan 1, 2000

By S. R. B. Cooke, H. S. Choi, I. Iwasaki

In a previous article1 the function of various fatty acids as collectors for iron ores was reported for the two alternate processes; (a) the flotation of iron-oxide minerals, and (b) the flotation of calcium-activated siliceous gangue. The selectivity of separation was shown to be markedly dependent not only on such common parameters as pH and the levels of collector and activator addition, but also on the structure and the degree of unsaturation of the acids used. The iron ores employed consisted primarily of hematite, goethite, and quartz and as the effectiveness of any one acid on the separation depends on the individual response of each constituent mineral toward the given collector, a comprehensive knowledge of the floatability of the individual minerals is desirable for the interpretation of the results obtained. The mechanism by which a collector ion becomes attached to a mineral-solution interface has been a subject of much investigation. From quantitative studies of the properties of the electrical double layer on mercury2 and on several solid surfaces3,4,5,6 , the adsorption of some flotation reagents at the mineral-solution interface is beginning to be understood. For example, it has been demonstrated from streaming potential measurements made on quartz5 and corundum6 that the interfacial electrical condition is strongly dependent on the pH. Thisoccurs presumably through the following electrolytic reaction at the interface, and in the presence of a flotation collector, controls the floatability of the solids. A concurrent investigation of the flotation behavior of goethite and of quartz carried out at the School of Mines and Metallurgy7 has shown a positive correlation with the electrokinetic behavior of these minerals. The purpose of the present investigation was to collect general information on the floatability of hematite, and to investigate the function of various 18-carbon aliphatic acids on the floatability of hematite, goethite, and of activated quartz. Electrophoretic mobility measurements, simplified flotation tests using a modified Hallimond tube, and contact angle and frothability measurements were employed. The results are of direct application in the interpretation of the batch flotation results on natural ores as

Jan 1, 1961

The first part (lH of this work dealt with the process of recrystallization of single crystals of lead after deformation by creep, as revealed by macroscopical examination. It was shown that when recrystallization commenced, a crystal, termed the primary crystal, started to grow at the edge of the specimen and extended into the body of the specimen along the slip planes. At some stage during the growth of this crystal, other crystals appeared at the boundary of this first crystal and fragments of the parent crystal. From thispoint, recrystallization was accelerated with relatively rapid necking down of the specimen until fracture occurred.All those crystals formed after the primary crystal were given the term secondary crystals. In the present paper is given a detailed account of the orientations of the primary and secondary crystals.EXPERIMENTAL METHODThe size of the test pieces and the manner of loading were given in the previous paper (1). X-ray back reflection photographs were taken of the individual primary and secondary crystals and from them were determined the orientations. The path of the X-ray beam was perpendicular to the surface of the creep specimen.In view of the large number of photographs needed, gold...

Jan 1, 1940

By Zhao-cheng Liu

Iron oxide red pigment powders of high quality were synthesized from pyrite cinders. Iron ox-ide red pigment powders were synthesized by hydrothermal method from the precursor of Fe(OH)3 and Fe(OH)2 colloid, which were obtained after ammonia solution reacted with acidic leaching solution produced by the reaction of pyrite cinders with sulfuric acid. Effects of reaction concentration, reaction temperature, reaction time, pH value and n(Fe2+)/n(Fe3+) on main properties of oxide iron red were studied by experiments. The prepared particles were characterized by means of X-ray diffraction (XRD) and scanning electron microscope(SEM). The results revealed that the synthesized iron oxide red particles were _-Fe2O3 and pseudocubic with particle size of 0.50~0.75µm. Furthermore, the quality of iron oxide red pigment powders reached the first grade of national standard (GB1863-89 ).

Jan 1, 2009

By Nino Catalano

The combination of two top levels of cross-lot braces designed and installed to act as a truss, and vertical post-tensioning of the panels allow the unbraced excavation of a 36' span. Philosophy of Excavation Support System The excavation of interest is for the cut-and-cover box sections of the southern approach to the Third Harbor Tunnel, which is part of the Central Artery/Tunnel project in Boston, Massachusetts. The 60' deep excavation is located very close to an existing building which is supported by piles, as shown in Figure 1. Therefore, it was necessary to minimize ground movement which may damage the building.

Jan 1, 1994

By Andrew Bamber

Between the early 20th Century and the present, the production of mined copper ore has increased from tens of millions of tonnes per annum to several billion tonnes per annum, an unprecedented increase. Contemporaneously, the average grade of mined copper ore has declined from over 2% to approximately 0.5%. Again, in parallel, the price of copper has increased dramatically to reflect the increasing cost of extracting and beneficiating such large amounts of low-grade ore. Within the period the copper price however exhibited several periods of intense volatility, driven by interrelationships between demand and supply, themselves strongly driven by periodic industry developments in the fields of exploration, ore extraction, mineral processing and extractive metallurgy. It is notable that these periods of intense innovation exhibit a strong correlation to preceding periods of price, demand or production volatility. This paper examines key trends in each theme between 1900 and 2018 and draws strong conclusions as to the interrelationship between them. INTRODUCTION The production of copper metal has increased from around half a million tonnes per annum to over fifteen million tonnes per annum over the course of the 20th Century. Contemporaneously, the average grade of copper ore mined has declined from over 2% to approximately 0.5% copper by weight. As a result, the volume of Run-of-Mine (ROM) copper ore required has increased from around ten million tonnes per annum to over a five billion tonnes per annum over the period, an unprecedented increase. The adage is that demand drives supply, that prices rise in times of high demand and/or short supply, and that prices fall when supply catches up with demand. The market sellers in biblical times knew this well; mediaeval market sellers equally. Dutch tulip sellers in the 1600’s experienced both in extremis — much to their dismay — and the great industrialists and early capitalists of the industrial revolution knew this also. Mining recently went through a cycle where investors and producers both believed that the “old” rules did not apply any more and that the industry was in a “supercycle” where prices would continue to rise on the back of increasing demand. However, as the GFC of 2008–2011 showed, this was not to be. Another adage says that we constantly innovate to lower costs of production. Is this true? Do we only innovate to lower cost? Has the true cost of producing copper actually gone down over the century? Or are there other balancing forces at play? Herb Kellogg, in his Centenary address to the American Institute of Mining Engineers (now SME), categorized two types of innovation: ‘Bigger and Better’, and ‘New Process’ (Kellogg, 1970). ‘Bigger and Better’ allows increased production at presumably lower cost; ‘New Process’ supports the same result at presumably the same scale, but at significantly enhanced efficiencies and (therefore) lower cost. It is suggested that both types of innovation are constantly and interchangeably required to achieve the kind of scale-up, at achievable operating and capital cost that the industry has achieved over the period. What can be shown, over this last Century and a bit, is that supply and demand are indeed inextricably linked, price and demand are linked, but so are price and cost of production. And the innovation required to sustain that weaves in between them all, cost-effectively increasing production capacity or lowering the cost of production at the same throughput, and sometimes both.

Jan 1, 2019

By Rose W. J

Geophysical prospecting was first recognized in Australia as an important aid to mining enterprises in 1927, when, on the suggestion of Sir Herbert Gepp, the "Imperial Geophysical Experimental Survey" was organized. The function of this survey was to carry out investigations on the applicability and efficacy of the most important geophysical methods under Australian conditions. The survey was formed under the joint auspices of the British Empire Marketing Board and Australian Commonwealth Government, and the investigations were carried out in Australia under the leadership of Mr. A. Broughton Edge, B.Sc., A.R.S.M., F.G.S., M.Inst.M.M., during the years 1928 and 1929. A description of the work performed, the apparatus used, the principles of the methods, and the results and conclusions of the survey are included in a report published by the Cambridge University Press in 1931.In 1932 Sir Herbert Gepp became interested in some gold mines in Eastern Victoria, in the Cassilis and Bethanga districts, and realizing that the lodes in these areas would be favorabIe for a geophysical examination, he arranged for a series of tests to be carried out. This work was performed by Mr. E. L. Blazey, B.E.E., a former member of the staff of the Imperial Geophysical Experimental, Survey, under the general direction of, and in consultation with, Mr. W. J. Rose, B.M.E.The work was commenced in October, 1932, at Cassilis, Vie., continued at Talgarno, Vie., .and concluded at...

Jan 1, 1933

By Frank Sames

Most Blasting Programs are developed focussing on the environmental impact with respect to blast vibration and airblast. Compliance with existing regulations or policies limiting the immissions are generally achieved through constrains in the blast design, or monitoring programs. Efficient monitoring programs combine compliance monitoring and blast assessment. Signals, which are obtained in the area of direct influence of the seismic source, can contain valuable information about the blast design parameters. Techniques to analyze blast vibration signals have advanced and can assist in understanding the contribution of individual blast parameters to blast vibration and airblast. Advanced signal analysis encompasses magnitude analysis, Fast Fourier Transforms (FFT) and frequency scans in the frequency domain, as well as filtering in the time domain. Through examples, the advanced signal analysis techniques and their limitations are described and discussed, showing the impact of blast timing, timing accuracy, charge configuration and the geology dependent transmission behavior. Optimization criteria and pragmatic monitoring programs can be developed on the basis of the most influential blast parameters. In addition, however, safety and the cost efficiency of the blasting program are essential to the success of an operation. That is where advanced signal analysis techniques can interface with blast planning, computer assisted modeling and information systems. A valuable process can be developed to ensure compliance with existing regulations and efficient risk management for mining operations, while tracking cost and supporting operational decisions. A conceptual blasting information system is presented.

Jan 1, 2000

By Joe Shoemaker

Automated Spot Generation ? No Operators below the Highwall ? No Operator Wear and Tear ? Reduced Swing Time ? Single and Double Sided Loading ? Minimized Bench Width

Aug 1, 2013

Computer applications are ideally suited to the day to day operations of grade control and short term planning on a mine site. By refining this part of the operation there is scope to increase profits by more accurately predicting ore grade and tonnage, and allowing the mining engineer more flexibility in his approach to scheduling. Large numbers of blasthole or ditchwitch samples need to be processed in a fast and efficient manner, and stored in a database for future reference. The mining engineer has to calculate tonnages and subdivide the blast or digging area into mineable areas of waste, low and high grade ore. New grade and tonnage information must be used by the mining engineer to update his short term plan. Answers must be obtained quickly and efficiently, but a high level of individual input is necessary in order that maximum use is made of the information. Geostatistical analysis of samples can be used to refine the interpolation techniques. Reconciliation between the original grade model, the newly sampled area, and the final product should be monitored continually.

Jan 1, 1989