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Chairman, MRS. JESSE SCOBEY The Foreign War Relief Committee closed its dispensary fund during the past month with a contribution to the American Fund for French Wounded of $1720.51, balance on hand, principal and interest, as a gift from the New York Section of the Woman's Auxiliary for pressing emergency dispensary work in France. The American Fund for French Wounded was authorized to cable this sun at once, in consideration of the fact that their existing dispensaries, including the one established by the New York Section at Briey, were in excellent condition, while their mobile dispensary fund was confronted by the most urgent need for work among the refugees now returning in pitiable condition and in great numbers to certain distressing centers. The committee sewing at Fund headquarters every week has had seven working days, with an enrollment of twenty: The average attendance was ten; largest attendance for any one day, thirteen; smallest attendance, eight. Interest in this activity is growing steadily and it is the intention of the committee to push the work vigorously for the next few weeks.

Jan 3, 1919

By W. M. Aubrey

Lying approximately 110 miles east of Toronto, Canada, the Marmora mine produces iron ore with a content of about 40 pct Fe, primarily in the form of magnetite. Operated by the Marmoraton Mining Co., a subsidiary of Bethlehem Steel Co., the orebody is mined by open pit methods. The ore from the pit is crushed, cobbed, ground to -100 mesh, magnetically concentrated to 67 pct iron, and then pelletized in shaft furnaces. The pellets are normally shipped by rail throughout the year from Marmora to Picton on Lake Ontario where they are unloaded and stored. Subsequently, during the navigation season, the pellets are shipped to Bethlehem Steel's Lackawanna plant in Buffalo, New York, for use in the blast furnace. At Marmora, the pellet plant demand and the concentrator output are not usually equal. To counter this problem, surge capacity in the form of storage pits in combination with a 30-ft diam thick¬ener has been provided between the concentrator and the pellet plant. Two sets of controls have been installed on this thickener, one controlling the…

Jan 9, 1960

By G. Cherkashov

A new hydrothermal field with massive sulfide deposits was discovered in 2004 at 16º 38.4?N, 46º 28.5?W on the Mid-Atlantic Ridge. Hydrothermal signals had already been recorded from bottom waters and sediments in this area during cruise 19 of R/V Professor Logatchev in 2000. This site was revisited during the 24th cruise of R/V Professor Logatchev in February 2004 when samples of massive sulfides were recovered and video records of the deposits made. The basalt hosted hydrothermal field is situated at a depth of 3700-3750 m, 600 m above the inner floor on the eastern slope of the rift valley. Structurally, the new field is located at the intersection of a deep along-axis marginal fault and a transverse sub-latitudinal dislocation. Six sulfide mounds as well as associated metalliferous sediments were mapped (sampled and/or recorded by video profiling) within the hydrothermal site. The largest ore body, 500 x 225 m, in the southern part of the field consists of small blocky talus and relics of sulfide chimneys partly covered by iron oxyhydroxides. The chimneys are 1-5 m high. The southern and western boundaries of the massive sulfide deposit have not yet been delineated. More than 1,100 kg of massive sulfides and stockwork mineralization were sampled at 7 sites by dredge and TV-grab. Everywhere, iron sulfides were the principal minerals present. Pyrite in association with lesser amounts of chalcopyrite occurs in both massive sulfides and stockwork mineralization. Of particular interest is the chalcopyrite-siliceous stockwork where silicified and chalcopyritized basalts are intruded by a network of chalcopyrite veinlets. These zones could be fairly thick and enriched in base metals. Sphalerite was very rare.

Jan 1, 2004

By Wayne I. van Drunick

"Energy balance modeling has recently been shown to be a competent tool in the estimation of SAG mill discharge rheology. Work performed by van Drunick and Moys (2001) validated the ability of an energybalance filter to estimate the slurry density from an operating SAG mill. The importance of rheological data is highlighted by several authors who show the effects on load behaviour and thus mill performance. Energy balance models were developed to account for the dynamic energies in the mill discharge sump. The models then made it possible to infer the mill discharge density. A sampling campaign was performed and the errors from the sump energy balance were within tolerable limits.Since the initial results were published, it has been decided to further develop the modeling techniques in order to focus on balancing the energies around the entire mill. The critical measurements for the energy balance will be the temperatures of all the streams entering and leaving the mill, including energy losses to the environment. Metso’s OCS© (Optimising Control System) currently controls the 3 SAG mills at Anglogold’s Mponeng Gold Plant (South Africa). The OCS has built-in Kalman filtering tools to effectively handle variances and noise in the models and the mill circuit data respectively. The new models are therefore constructed in the OCS platform, and will be run in parallel with Metso’s current modeling and filtering systems. The work is a collaborative effort between Anglogold, the University of the Witwatersrand and Metso. The benefits of energy modeling, compared to mass modeling, are that energy data are more accurately measurable than mass data. The inferred mill parameters can therefore be improved provided that a competent set of models is produced to process the (accurate) thermal measurements."

Jan 1, 2003

By Yan Beygelzimer, Alexander Spuskanyuk, Victor Varyukhin

"A cellular model of the plastic deformation of polycrystalline aggregate is proposed and comprehensively described. Representative volume element (RVE) of a solid body, that is being deformed, is described as a population of interconnected units that, in turn, can consist of lower scale level units. Sliding along the various allowed sliding systems deforms simple units, which do not have an internal structure. For consideration of stress distribution within the limits of components, the approach of self-consistent field is used. Rotation of units and moment stresses connected with it are taken into account. Results of computer experiments are analyzed.1. IntroductionMicromechanical models of polycrystals are a link between the research of plastic deformation on micro and macro levels. Computer simulation of inelastic strain of polycrystals has found a great deal of interest as well. Despite the fact that this approach does not allow to obtain macroscopic constitutive relationships that are used in deformed solid body mechanics, it clarifies essential features of the phenomena in many aspects. First of all, it concerns effects stipulated by interdependence of micro-level and macro level of plastic deformation processes. Also, with the computing mechanics, instead of constitutive relationships, the adequate computer models can be used. Broad possibilities for computer simulation of various processes are opened by cellular automata approach. By means of numerical experiments, the cellular automata allows to study the macro behavior of the whole ensemble of cells depending on the local microscopic laws that define evolution of each cell and its interaction with the closest environment.We propose a mathematical model of a polycrystalline aggregate (the cellular model) based on a self-consistent scheme and on the interaction law similar to the one by Berveiller and Zaoui [1]. Our original solution is the self-similar structure of cellular automata that allows modeling of the fractal nature of real materials (Figure 1). The goals of this work are to present the major structures and relations of cellular model of polycrystal and to test this model for its adequacy as for describing known effects and dependencies. Identification of the model and its application for studying of concrete polycrystals are put aside for the future research."

Jan 1, 2001

By Charles T. Holland, David A. Olsen

Considerable work has resulted in the development of a formula by which the strength of coal pillars for an L to T ratio of up to 12 may be estimated. One of the factors involved in this formula is the coefficient of friction between the coal pillar and the adjacent rock with which it is in contact. This paper presents the results of studies on sandstone, limestone, shale and coal and the coefficient of friction between coal and the other three under wet and dry conditions. With the coefficients of friction thus determined and the use of results obtained earlier by Meikle and Holland, it seems probable that coal pillar strength may be more closely estimated. Several investigators1-3 have found that the com-pressive strength of cubical coal specimens can be correlated by an equation such as

Jan 1, 1969

Improve the safety of salt mine workers by providing a means for quickly identifying areas within the mine that?s how an increased potential for gas and salt outbursts. Approach Outbursts occur in salt mines when a high-pressure pocket of gas is intercepted during the mining process, resulting in a sudden and sometimes catastrophic expulsion of gas and salt. In one case, the amount of gas released through such an event caused an explosion that resulted in five fatalities. The U.S. Bureau of Mines has designed and developed a gas outburst prediction system that can quickly determine the potential instability of areas within rock salt mines. The determination is based on noise measurements obtained from samples of the salt as they are dissolved in water. This system improves upon technology currently available because it provides information in only a few minutes instead of in several days. In addition, present prediction systems are not only time consuming, but expensive because they require laboratory conditions and highly trained personnel to operate them and determine results.

Jan 1, 1989

By George Watson, Gu Quanzhong, S. Gerard Sawyer

Bulkheads, also known as hydraulic seals, are used to seal abandoned workings and protect adjacent active mines from explosion and control unwanted inflows of water from poorly sealed shafts, water-bearing strata, and abandoned mine areas or gobs (1). At coal seam outcrops, bulkheads have typically been used to prevent access and to control acid mine drainage. Bulkheads have also been installed at outcrop openings located within the footprint of an embankment dam, or within the reservoir of an impoundment, to prevent stored water or slurry waste from flowing into active or inactive underground mine workings (2). Components of MICON Bulkhead Seal MICON bulkhead seals in mining applications refer to seals designed to impound liquids or slurry. The MICON bulkhead seal is comprised of two concrete block walls set in the front and back and a polyurethane/aggregate core (Figure 1). The two walls are usually dry-stacked, surface-bonded walls constructed with solid load-bearing concrete blocks (ASTM C90) or concrete building brick (ASTM C55). The surface bonding material used in the wall construction must be MSHA-approved. The type of stone, if any, used to fill the space between the walls is not essential. However, MICON generally uses No. 57 limestone in 50 lb. bags, specified to moisture control, shrink-wrapped and palletized. The polyurethane foam used in the construction of the bulkhead seal is engineering specified and formulated by density based on the optimization of cost, seal core thickness, required adhesive strength, the use of stone filler and other required physical properties.

Jan 1, 2005

By E. H. Kelton, R. D. Grissinger

E. E. Schumacher.*—DO YOU control the humidity in your test room? What effect does the environment have on your results? E. H. Kelton.—We do not attempt to control the humidity. As a matter of fact, the humidity in the beam tests that were conducted in a constant-temperature room varied widely and, as far as we know, there is no effect. The tension tests were conducted largely in an oil bath. I suppose there would be an effect in highly corrosive atmospheres, sufficiently corrosive to notch the specimen; otherwise, I would say none. E. A. Anderson.*—The effect of the humidity on the corrosion of zinc does not become important until the relative humidity is 70 per cent. At that point the corrosion products are capable of absorbing moisture and the corrosion rate increases. Below that point corrosion is almost imperceptible. This does not take into account any effect due to stress. That may be important. E. E. Schumacher.—Recently 1 have become very conscious of the enormous effect that surface films can exert on the physical properties of certain alloys. Shortly, we are publishing an article in which it will be shown that the fatigue endurance of some lead alloys can be changed markedly by merely changing the type of film placed on their surfaces. Changes as great as tenfold were observed. These findings make me wonder whether in your creep test you might not obtain quite variable results, depending upon the type of liquid medium used to immerse your specimens. Did you use more than one type of oil and, if you did, what were your results? E. H. Kelton.—I think we have used no more than three different oils, and we could not see any difference in effect.

Jan 1, 1945

By Chaitanya "Teny" Mittal

INTRODUCTION A team effort by the Owner, Engineer, and Contractor can help avoid serious problems on a construction project. It can save cost and time for both Owner and Contractor, as illustrated in the following case history of the West Zone and Siouf Keblia Collector System in Alexandria, Egypt (Contract 02-AID-83/84). Under the bilateral agreement made in 1980 between the United States of America and the Arab Republic of Egypt, the United States, through the Agency of International Development (USAID), gives approximately $1 billion per year as a grant to Egypt for various development projects. The Alexandria Wastewater Management System was selected in 1981 as one such project. The Egyptian Government Agency responsible for this work is the Alexandria General Organization for Sanitary Drainage (AGOSD). A joint venture of two U.S. consulting engineering firms, CH2M HILL, Inc., and Metcalf & Eddy, Inc., called Wastewater Consultants Group, along with two local subconsultants, Engineering Consulting Group and Warith Engineering Co., were selected by AGOSD to study the sewer system and develop a plan to serve the immediate and long-range sewage disposal needs of Alexandria. Wastewater Consultants Group is currently involved in Phase I of the Master Plan. This initial step in providing Alexandria with an operating sewerage system for the current and near-term population (year 2000) consists of the design and construction management of 140 kilometers of collector and force main pipelines (including 9 miles of pipe jacking and tunneling in very soft clay), five new pumping stations, extensive rehabilitation of two treatment plants (built in the 1960s but never operated successfully), and installation of a sludge handling system. Phase I is scheduled to be completed by the end of 1991 at a total cost of around $250 million (US) plus 250 million

Jan 1, 1989

By H. C. Goodrich

AT THE Utah Copper mine, steam shovels were first used, in 1906, for the removal of overburden, and in June, 1907 for the mining of ore. Prior to 1907, the ore came from underground development work and from stoping. The use of the steam shovel gradually increased until 1914; since then all material, both overburden and ore, has been loaded by power shovels operating on the various benches of the mine. During FIG. 1.-SCENE OF UTAH COPPER MINE BEFORE OPEN-PIT MINING WAS BEGUN. these 19 years, there has been a great improvement in open-pit mining; largely in the use of equipment having greater capacity and dependableness. The history of the development of mechanical shovels and related equipment, as affecting the Utah Copper Co., would be interesting and would justify considerable space; but of greater interest at this time is the operation of the equipment now in use. The Utah Copper mine is in a great deposit of copper-bearing monzonite, which occurs as a prominent headland of the Oquirrh range of

Jan 9, 1925

By M. F. Werneke, J. A. Jones

The use of a unique class of sulfhydryl collectors, the monoalkyldithiocarbamate salts (RNHCS2M) as direct collectors for malchite and azurite is presented. Microflotation and laboratory scale flotation tests were performed to define the collector properties of these reagents under a variety of flotation conditions. On the basis of the results, it is proposed that some property of the amine-hydrogen atom in the reagent has a signification influence on the unusual activity of these collectors for oxide copper minerals.

Jan 1, 1979

By M. F. Werneke, J. A. Jones

Abstract- The use of a unique class of sulfhydryl collectors, the monoalkyldithiocarbamate salts ([RNHCS]) as direct collectors for malachite and azurite is presented. Microflotation and laboratory scale flotation tests were performed to define the collector properties of these reagents under a variety of flotation conditions. On the basis of the results, it is proposed that some property of the amine-hydrogen atom in the reagent has a significant influence on the unusual activity of these collectors for oxide copper minerals.

Jan 1, 1978

By E. S. Peterson, M. K. Harrup, K. A. Dolbeare, J. E. Wey

Efficient methods for the removal of copper from heap-leach solutions without mobile organic phases are a current mining industry need. To satisfy this need, a selective, high-capacity, durable solid material is required. The Idaho National Engineering and Environmental Laboratory (INEEL) developed a set of materials based on current solvent-extraction chelates that provide selective copper concentration in the presence of high concentrations of iron. In contrast to conventional solvent extractions, the author's strategy anchors the chelators to a nonpolymeric solid substrate through the use of a custom-designed linker molecule. The fundamental synthetic routes to these materials have already been established, and attachment to the solid surfaces have been achieved in an efficient manner. The author's continuing research is focused on the optimization of the synthetic pathways to these solid materials and the evaluation of their copper-capturing capabilities.

Jan 1, 2003

By Alfred Jr. Petrick, William A. Vogely

INTRODUCTION The scope of mineral finance extends beyond the economic aspects of property evaluation to all of those activities involving acquisition and utilization of funds with an objective to optimize the value of the firm. It must, therefore, en- compass consideration of the overall financial goals of the firm, decisions involving external versus internal growth and domestic versus foreign investments, management of working cap- ital, efforts to minimize the cost of capital, and decisions with regards to the instruments of long- term debt and equity financing. The scope of this section is limited to considerations of special interest to the mineral or petroleum engineer, which include the following aspects of mineral finance: (1) The technical aspects of mineral or coal property or oil and gas reservoir evaluation which provide the basis for estimation and forecasting of revenues and costs. (2) Estimation and forecasting of costs and prices in a inflationary economic environment. (3) Calculation of cash flows which model .. , the investment in minerals, coal or oil, and gas. Such models require assumptions as to the timing of cash flows, escalation of capital and operating costs, base prices, and escalation, the tax regime, royalties, division of profits and the economic aspects of loans. (4) The role of discount rate in the economic analysis of an investment which requires consideration of the opportunity costs of the firm, cost of capital, risk premiums. (5) Risk analysis including application of the concepts of conditional net present value, expected value, and risk preference as well as the application of the techniques of sensitivity and simulation. (6) Selection of application criteria for in- vestment decision making. (7) Capital structure with particular reference to the effect of debt financing. (8) Consideration of sources of funds utilized by the minerals industries. (9) Long-range planning including portfolio analysis. This section is limited to principles, methodologies, and trends in mineral investment, finance, and long-range planning in the United States with a perspective from the year 1984. Consideration of the key concepts is supplemented by case examples of investment risk analysis and financial structure. Important factors affecting mineral investment evaluation during the 1980s include volatile metals prices, cost inflation, and the introduction of techniques requiring the computer and its capacity for improved technical and economic analysis into the hands of those who know most about the industry. The personal computer is replacing the calculator on the desk of the individual analyst and is rapidly becoming a required tool for the study of engineering and economics. Examples of change brought about by the micro-computer include greatly improved techniques of cost estimation, wider application of the computer for project analysis, computer graphics, reserve estimation, geostatistical analysis, mine design and other techniques that capitalize on the ability of the computer to handle

Jan 1, 1985

By H. W. Hintze

Coal handling facilities, such as utility plants, coal terminals, ports, manufacturing, processing, etc. Protect themselves against interruptions in coal receipts by maintaining a 60 to 90 day supply in storage. Not too long ago, these storage piles were referred in terms of hundreds or thousands of tons. Today, it is not unusual to have hundreds of thousands or millions of tons in storage. Burn, or shipping and receiving, rates have increased dramatically and storage piles have grown in horizontal as well as vertical dimensions. Fixed systems for delivering and retrieving coal from storage have increased in length and operating capacity and have become highly sophisticated in their operation. With few exceptions, mobile material handling equipment is used to handle all coal beyond the reach of these systems. These machines take excess loose coal from the fixed system to the storage area, place it on the storage pile, compact it, maintain the pile, protect against spontaneous combustion, the spread of fires if they occur, and return the coal to the reclaim system as required, plus many of the small chores around the facility.

Jan 1, 1981

"Silver is traditionally recovered in base metal smelters (lead and copper), or as a by-product of other precious metals (gold and/or PGM's). This paper presents the results of non-conventional techniques to recover silver from complex materials. The PLATSOL® process has been developed to recover, in one step and without the use of cyanide, base metals (copper, cobalt, nickel) and precious metals (gold, PGM's) from sulphide concentrates too low in grade to enter the mainstream extraction processes. Silver is only partially recovered in solution with gold and the PGM's during the PLATSOL® process. However, the silver minerals are transformed into silver chloride, which can then be recovered from the PLATSOL® residue using conventional techniques. Some South American silver concentrates contain levels of impurity (mostly arsenic) so elevated that the penalties incurred significantly affect the process economics. The present results have shown that a low temperature calcination process transforms the concentrate into a product well suited for traditional recovery treatments. Metallurgical details will be provided, as well as the results of mineralogical studies that helped clarify the process mechanisms.IntroductionSilver occurrences in nature are very diversified, and, therefore, primary silver is produced as a by-product of many base metal and precious metal operations [1], as well as a co-product of most gold ores. However, difficulties can arise when high temperature processes are used for refractory gold ores or copper concentrates, or when the silver concentrate contains impurity elements such as arsenic that trigger high penalties."

Jan 1, 2012

By Z. M. Zavodni, C. D. Broadbent

"Major rock slides in open-pit mines are rare, but they can develop in spite of sophisticated slope engineering design practice. Experience has shown that, except under high seismic load conditions, the serious slope instability condition is almost always accompanied by the gradual development of one or more tension cracks behind the slope crest, allowing for time-displacement monitoring. Continuous surface displacement measurements with attendant prompt analyses are usually adequate for the prediction of slope behaviour.This paper describes efforts that have been made to quantify parameters associated with slide movement, and compares the displacement records of several large-scale open-pit porphyry copper mine slope failures. Two principal failure stages are recognized in the typical slope failure leading to total collapse: (a) REGRESSIVE STAGE, during which the failure will re-stabilize if some disturbance external to the rock and structure is removed; and (b) PROGRESSIVE STAGE. during which the failure will gradually displace at an accelerating rate to the point of total collapse unless active control measures are taken. Over-all displacement records in both failure stages are apparently of simple exponential form. with a definite break occurring at the onset-of-failure point.Certain common empirical relationships are suggested for the large-scale slope failures analyzed in this study. Based on plots of displacement rate vs time prior to collapse, a semi quantitative empirical relationship is presented for failure collapse prediction. The comparison of historical slide displacement records furnishes the operating engineer with practical guidelines to estimate the characteristics of future large-scale slope failures."

Jan 1, 1980

By Ted Nuorivaara

The use of polymer-surfactant mixtures as foam stabilization agents is a topic that has drawn the attention of several fields but has so far not be thoroughly studied in the context of mineral froth flotation. The present work showcases a study on the impact on flotation performance of cellulose surfactant derivatives and their mixtures with commercial frothers. Bubble size and foam property measurements were run in a two-phase system along with laboratory-scale flotation experiments conducted using a porphyry copper ore from a mine in Finland. A comparative analysis on recovery, grade and flotation kinetics is presented on the products obtained using: i) a partially hydroxylated cellulose derivative (i.e. hydroxypropyl methyl cellulose; HPMC), ii) a commercial polyglycol-ester frother (Nasfroth240; NF240), and iii) mixtures of these two. The results show that using frothers with a total concentration of 30 ppm, the HPMC-NF240 mixtures provide advantages in terms of Cu recovery, (i.e., up to 95%), compared to the use of either NF240 (ca. 76%) or HPMC alone (ca. 1%). Interestingly, only a small proportion of HPMC mixed with NF240 was sufficient to produce a measurable increase in recovery. This improved performance was attributed to a synergistic effect of the polymer-surfactant mixture which further reduced the bubble sizes in a two-phase system compared to that of NF240. The present work offers a further step into understanding the phenomena taking place when a short chained surfactant is either substituted or mixed with a cellulose derivative, offering potential ways of exploiting this behavior for the enrichment of minerals. INTRODUCTION Froth flotation has been the predominant technology used to beneficiate sulfidic copper minerals such as chalcopyrite ever since it was invented in the late 19th century. The reason for the domination of flotation technology lies behind its versatility in selective separation as well as relatively cheap operational costs (Wills & Finch 2015). Even though flotation of sulfidic copper minerals is moderately well understood based on the broad research work done around the subject (e.g., Albijanic et al., 2015, Bournival et al., 2017, Wang et al., 2015, Mikhlin et al., 2015, to cite only a few), the modern era presents new challenges to the primary raw material industry, including questions regarding sustainability of mining operations accompanied by a need to improve the process efficiencies due to declining ore grades (Edraki et al., 2014).

Jan 1, 2019

This paper presents a review of computer techniques for the automatic contouring of geological and geophysical data with output as interactive display on graph plotters or graphics terminals and passive display on automatic drafting tables. The advantages of the method of fitting a triangulated surface to randomly distributed data using an advancing front algorithm are described, as well as the technique for determining interpolated values for the production of contour line segments and a contour smoothing algorithm. This contouring method is employed by the Geological Survey of Queensland and is implemented as an interactive system. An alternative method ideally suited to randomly distributed data involves the use of piecewise parametric cubic splines. This method which is ideal for sharp variations in magnitude and areal extent typical of geophysical anomalies is discussed. The mathematics of surface interpolation using non-parametric splines and an explicit piecewise surface fitting technique are discussed. Curve tracing techniques which are suitable for automatic contouring are also presented and the inherent advantages of interactive contouring using on-line plotters and graphics terminals for previewing of displays are described.

Jan 1, 1977