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By B Dold

"Mining has still today high potential for improvement in the exploitation efficiency. Especially low-grade ores have very low recoveries. In Cu bioleaching operations from porphyry copper deposits extraction of only five and 15 per cent with maximum of 40 per cent are reached. This means that 60–95 per cent of the resource is not exploited. Consequently, any metal not extracted will end up in the waste material, therefore increasing the risk of environmental pollution. This inefficiency is mainly due to the use of element concentrations for decision-making on the daily basis of a mining operation (eg cut-off ore grade, acid-base accounting – ABA). If, instead, quantitative mineralogical and geochemical data together with information on the bioleaching behaviour of the ore assemblage (the biogeometallurgical approach), is used for decision-making right from the beginning of the exploitation, higher recoveries and less environmental impact can be achieved, ie an increase in sustainability can be reached.CITATION:Dold, D, 2016. The Biogeometallurgical Approach – the Information We Need to Increase the Sustainability of Mining, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 169–172 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

A revolutionary development in blasting materials has occurred in recent years. Ammonium nitrate, sensitized by the addition of a small percentage of No. (class) 2 diesel fuel or other suitable petroleum product, has been adopted as a low-cost, efficient blasting agent2 in a wide variety of mining, quarrying, and heavy construction operations. Moreover, the ready availability of the component supplies throughout the Nation, together with the ease of formulating them into effective blasting agents, has made it possible for the blaster himself to prepare the mixes at the site of use. Recently, most established explosives manufacturers have begun supplying premixed AN-FO (ammonium nitrate-fuel oil) or a comparable product to various mining operations. However, many individuals and small business establishments are marketing premixed products prepared in facilities that are often poorly constructed and poorly located. Although these blasting agents have partly or wholly displaced explosives such as dynamites in many applications, there are some blasting operations in which the fuel-sensitized ammonium nitrate agents do not appear to be well adapted. As long as the hazards they present are clearly understood and respected, ammonium nitrate-based blasting agents have important safety characteristics when prepared under competent factory control or field-mixed under equivalent close control. This publication attempts to summarize the knowledge of those hazards and to incorporate practical ways to cope with them.

Jan 1, 1963

By Allen V. Heyl

This old district is a major zinc and lead source and minor copper and barite source. Ores are chiefly in the Galena Dolomite and in limestones and dolomites of the Decorah and Platteville Formations, all of Middle Ordovician age. Locally, deposits have been mined from Lower Ordovician dolomites and Upper Cambrian sandstones. Small deposits of lead, zinc, and iron sulfides have been found in Upper Ordovician Maquoketa Shale and in Lower and Middle Silurian Edgewood, Kankakee, and Hopkinton Formations. No post-Precambrian igneous rocks are known in the region, and the granitic and metasedimentary Precambrian basement rocks unconformably underlie the district at depths of 1500 to 2000 feet. The strata are gently flexed and faulted, probably largely the result of gentle compressive and rotational adjustments in the underlying crystalline basement, especially along lineaments between basement blocks. Folds of three orders ·of magnitude are recognized, and many related reverse, strike-slip, and normal faults of small to moderate displacements are present. Zinc-lead deposits are commonly linear, arcuate, or elliptical in plan. Most ore occurs as vein fillings in fractures and as breccia fillings and lining vugs, but some is in bedded replacements and impregnations of wall rocks. The ore is in shears, small reverse and bedding- plant faults, joints, and solution-slump structures related to intermediate and small folds. The main primary minerals in their general sequence of deposition are quartz, illite, dolomite, pyrite, marcasite, cobaltite(?), sphalerite, galena, chalcopyrite, millerite, barite, and calcite. Wall-rock alterations include solution of the carbonate rocks, silicification, dolomitization, clay alteration, and sanded dolomite. Oxygenisotope, trace-element, lead-isotope, and sphalerite- stratigraphy studies are in progress. Fluid inclusions in sulfide and gangue minerals are filled with concentrated brines at 120° to 40°C. Sulfides are directly replaced by supergene minerals above the water table at 50 to 100 feet in depth. In this relatively cool climate and limestone environment, smithsonite is in pseudomorphs after sphalerite; solution transport and redeposition of supergene minerals are rare. Ore genesis is postulated by rising hot-water solutions-a mixture of heated connate, magmatic, and meteoric waters.

Jan 1, 1968

By R. Hogg, Y. Lee, D. E. Rannels

"Lee, Yu-Chen, Richard Hogg, and D. Eugene Rannels. Extracellular matrix synthesis by coal dust-exposed type II epithelial cells. Am. J. Physiol. 267 (Lung Cell. Mol. Physiol. 11): L365–L374, 1994.—Although integrity of the alveolar basement membrane may influence progression of lung injury induced by inhaled particulates, little is known about direct effects of coal dusts on the alveolar epithelium or its extracellu¬lar matrix (ECM). Effects of dust on synthesis of cell and ECM proteins by type II cells (T2P) was thus investigated. Three coal dusts (anthracite no. 867; bituminous no. 1451 and no. 1361) and mine dust MIT-3, of respirable size, were studied as a function of dose and time over 3 days of primary T2P culture. On day 1, 750 µg/ml of 867 were required to increase relative synthesis of ECM proteins (ECM/cell). MIT-3, 1451, and 1361 were without effect. By day 3, 867 or MIT-3 increased ECM/ cell 60-100% at 300 µg/ml; 1451 produced modest, dose-dependent stimulation, whereas 1361 remained without effect. None of the dusts caused significant cytotoxicity. The results show dose- and time-dependent effects of well-characterized coal and mine dusts to modify partitioning of newly synthesized proteins into the ECM and suggest that coal dust exposure may modulate structure or function of the subepithelial basement membrane.basement membrane; cell culture; inorganic dust; lung injury; extracellular matrix deposition; pulmonary epitheliumCHRONIC EXPOSURE to coal dust may be associated with development of pulmonary fibrosis and consequent loss of normal lung function (see Ref. 26 for review). Al¬though the pathways of inorganic dust-induced lung injury are recognized to involve an inflammatory re¬sponse, the underlying pathogenic mechanisms are not understood in detail. Acute and chronic responses to dust exposure involve a variety of interacting cells of the immune system, including macrophages, T cells, and B cells, along with pulmonary fibroblasts. These responses reflect direct effects of the dust particles, as well as indirect effects mediated by soluble factors, including cytokines and eicosanoids (see Ref. 41 for review).Studies of pulmonary macrophages and fibroblasts following silica exposure suggest that dust-induced damage at the airway surface may involve cellular injury through oxidant-mediated pathways. Coal dusts and related inorganic particulates can activate the alveolar macrophage (42) to produce fibronectin (15) and cytokines, such as interleukin-1 or tumor necrosis factor (4) and/or other soluble products which act locally (29) to cause acute cellular injury and to initiate the progression of fibrotic lung damage (16). Type I epithelial cells are typically more susceptible than type II cells to oxidant injury. Type I cell damage and subsequent death leads to denudation of the subepithelial basement membrane (2, 21) and can be associated with leakage of plasma constituents from the pulmonary vasculature into the alveolar compartment (13)."

Dec 1, 1995

By Eldon L. Brown

Location and History The Sherritt Gordon property is located in northwestern Manitoba, about 100 miles north of The Pas and 40 miles northeast of Flin Flon. It is connected with the Manitoba Northern railway, which runs from The Pas to Flin Flon by a branch line, 42 miles in length. The location of the property is shown on the sketch-map, Figure 2. The ore deposit was first discovered by Philip Sherlett, a Cree Indian, in 1922. In 1924 Sherlett's claims lapsed and the ground was re-staked by Carl Sherritt and Dick Madole, and was optioned by them to J. P. Gordon in the summer of 1925. Gordon re-optioned the property successively to three well-known mining groups, one of which did some surface trenching .and put down 28 shallow diamond-drill holes before dropping their option. In the latter part of 1927, a Company known as Sherritt Gordon Mines, Limited, was formed to take over the property, and preparations were made for systematic development work. Preliminary Development In order to fill-in gaps left by the original drilling, a light diamond-drill outfit was flown-in to the property from the Hudson Bay railway in the early fall of 1927. Ten shallow holes were put down before freeze-up .and a considerable amount of surface trenching was completed. Based on the results of the surface trenching and the shallow diamond-drilling, an extensive development campaign was outlined. A winter road, 90 miles in length, was cut from mileage 55 on the Hudson Bay railway, and during the winter of 1927-28 a total of 2,600 tons of freight was hauled-in to the property. This freight included four complete diamond-drill outfits, two complete mining plants, building material for two sets of camps, and supplies for one year's operations, including 105,000 gallons of fuel-oil for Diesel engines.

Jan 1, 1933

By Y. Lahaye, O. Martinsson, B. I. Palsson

"Four main and three minor rare-earth-element (REE)-bearing minerals were identified and quantified in the Kiirunavaara apatite iron ore tailings using optical microscopy, an electron probe microanalyzer (EPMA) and a mineral liberation analyzer, and their chemical compositions were analyzed by the EPMA and laser ablation inductively coupled plasmamass spectrometry. REEs are shown to be contained in the minerals apatite, monazite, allanite, titanite, zircon, thorite and synchysite. In zircon, thorite and synchysite, they occurred in only trace amounts and contributed limited amounts to the total REE budget, and these are consequently of minor importance. Monazite occurred as inclusions in apatite and as free particles, 90 percent liberated. Allanite occurred to some degree in mixed grains with magnetite but also as free particles. Monazite mainly reported to the apatite concentrate, while allanite and titanite largely went to the tailings, the latter preferably to those fractions smaller than 38 µm. The amount of titanite in the finest tailings fraction was 2.3 weight percent, containing close to 1 percent REEs, with heavy rare earth elements (HREEs) making up 28 percent of the total REEs. However, a texturally distinct group of titanite grains showed an HREE/REE ratio of up to 67 percent. Furthermore, titanum dioxide analyses indicate that titanite is preferentially released into the tailings from the secondary magnetic separation step in the concentrator. Our data therefore suggest that titanite, occasionally enriched in HREEs, can be extracted from the processing stream and might thus be considered a new source for REEs at Kiirunavaara and similar deposits.IntroductionDeposits of apatite iron ores are the major source for iron in the European Union and are exploited by Luossavaara-Kiirunavaara AB (LKAB) in several mines in the Kiruna-Malmberget area in northern Sweden. Kiirunavaara is the largest of the apatite iron orebodies in Sweden, comprising more than 2 Gt of iron ore with 60 to 68 percent iron (Fe). At the end of 2015, the total accumulated production of crude ore from openpit and underground mining since the start of mining was 1,566 Mt, with ore reserves of 644 Mt grading 46.3 percent Fe (LKAB, 2016). The deposit defines a steeply dipping tabular body, approximately 6 km long and up to 180 m thick, extending at least 1,500 m below the surface. It is situated in the middle part of the Palaeoproterozoic Kiirunavaara Group of volcanic rocks and follows the contact between a thick pile of trachyandesitic lava and overlying pyroclastics (Martinsson, 2004)."

Jan 1, 2017

By M Edgar, G Pattemore, M Auad, K Job, A Job, S Gale

In recent decades, significant advances have improved the modelling techniques for predicting slope failure. Predicting failures is vital in open pit mining due to the significant risk posed to personnel and equipment from unstable pit walls. Failures not only cause harm and damage to people and equipment but also cause delays to production and subsequently increase operational costs. Coupled with improvements in modelling techniques, utilisation of advanced scanning systems, such as high-definition imagery from UAVs has enabled faster and more precise mapping and modelling. However, one key element required for accurate slope stability modelling and monitoring is the ability for mine geotechnical engineers to have an accurate understanding of the mineralogy and moisture content of slopes, in real-time. To address this challenge, research has been undertaken to utilise hyperspectral imaging across a broad spectrum, combined with high-definition imagery, and LiDAR to scan slopes for minerals and moisture content. In addition to accurately mapping mineralogy and moisture, the data must be collected autonomously and remotely to ensure ongoing safety. The results show that there are many direct and indirect benefits from this new technology, including the ability to monitor slopes at a safe distance and in real-time, improved accuracy of modelling, detection of risks, and improving the automation workflow for geotechnical engineers. The paper presents recommendations for the implementation of the technology in open cut mining environments.

Jun 22, 2022

By A A. Roberts, R F. Dewhirst

"Extensive literature surveys, research in the project environment and personal experiences both within and consulting to project teams have revealed some consistent ‘people factors’ that contribute most to ultimate project success. Outside of purely technical and business case issues, there are a small number of leadership characteristics – probably only ten – that if correctly applied can positively leverage a team’s impact on project success.Of the top seven project success characteristics that were consistently highly rated in a recent study, five of them were around leadership. The authors have focused on this topic, noting that good leaders need to display the following traits:passionate commitment to deliveryconsistent modelling and reinforcement of correct values and behaviourfocus on managing relationships well and energising teams and individualscarefully clarifying project vision from front-end loading stages onwardseffective decision making.Not every project manager can and does practise these behaviours all of the time, but being aware of them and receiving training or facilitation in improving their application of these skills can equip project managers with the essential tools to markedly improve their own performance and that of their teams.This paper draws upon experiences in the field and provides lessons – both good and bad – to illustrate. As well as examining leadership traits, the way in which a leader can establish, organise, motivate his or her team and ultimately lead them to success is examined. The paper shares methodologies that have been successfully used to track status within a team and generate appropriate recovery plans where required.In particular, the paper will examine a case study based on an amalgamation of real project issues in some challenging situations using virtual teams (ie physically distant teams located in different centres) to illustrate the importance of strong and positive leadership in achieving success across geographies, time zones and languages.CITATION:Roberts, A A and Dewhirst, R F, 2016. Leadership in projects – a recipe for success, in Proceedings Project Evaluation 2016, pp 49–58 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By J. H. Chesters

The main, though rarely mentioned advantage, is likely to be the standardisation of best practice and product. In a batch process conditions vary cyclically, but with a continuous process they would, at least ideally, remain the same for long periods of time. The other main advantages of continuous over batch processes are likely to be reduced operating and capital costs, the improved possibilities for automatic control, and more consistent product quality. Recent developments are surveyed for ironmaking and steelmaking with reference to blast furnaces; solid-product and molten-product direct reduction; the trough-type processes of Thring, Worner, the Japanese National Research Institute for Metals and Glinkov; basic-oxygen furnace (LD) variants; spray steelmaking; continuous casting and vacuum degassing; rolling; and coating. Encouragement in the devleopment of continuous processes may be drawn from the way unexpected difficulties, such as trouble with sulphur and refractories, were tackled and overcome to achieve the float glass process

Dec 1, 1971

By G. R. Hopkins

According to reports received by the Bureau of Mines, Department of the Interior, as of January 1, 1934, there were 591 completed refineries in the United States, an increase of 86 ever the total reported at the beginning of 1933 and the largest total ever recorded. It should be noted that the 1934 total, although large, probably does not include more than half of the "pot-still" plants of 1 barrel to 50 barrels daily capacity which have sprung up within the last 2 or 3 years and about which very little information is available. However, the combined operations of these snail refineries are of negligible importance as altogether they refine less crude than one plant of average size. Of the completed plants, 454 were operating on January 1, 1934 and 137 were shut down. In addition, 13 refineries were under construction on January 1, 1934. Compared with the previous year these data indicate a marked increase in the number of operating plants, little change in the number of inoperative plants, but a decline in' the number being built. The material gain in the number of operating plants resulted primarily from the construction off approximately 25 refineries, averaging about 100 barrels capacity in the Kooky Mountain district, as well as from the addition of about 20 plants in the East Texas field.

Jan 1, 1934

By K. Luxbacher, A. Haghighat, B. Lattimer

Mine face ignition due to high levels of methane is one of the most common fire incidents in underground coal mines. In continuous miner headings, depending on the magnitude of the ignition or resulting fire, auxiliary ventilation controls may be damaged or dislodged, affecting the ventilation into the area. A computational study was conducted to investigate the effects of different levels of damage to an exhausting ventilation curtain in a continuous miner heading, and the impact on ventilation to the face. The computational fluid dynamics software Fire Dynamics Simulator (FDS) Version 6.0 was used to predict the conditions that develop due to a 200-kW fire in the face following a methane ignition with different levels of assumed ventilation curtain damage. Smoke layer depth, temperature and mass flow inby the last open crosscut were used to evaluate the impact of no damage to the curtain, partially dislodged curtain, and fully removed curtain. As more of the ventilation curtain was damaged, smoke depth and temperature outby the fire increased. With the full removal of the curtain, the smoke accumulated from the last open crosscut to the face, with the ventilation completely bypassing the continuous miner region.

Jan 1, 2016

By J Seppelt, B Akerstrom, A Rice, J Bubnich, T Waters

The Concentrator 1 plant at Cadia transitioned from Cadia Hill open pit to the Cadia East block cave ore body in 2013. As a result of this change, major plant upgrades were required to achieve the desired throughput while treating more competent ore. The 40-foot (40’) SAG mill now receives a feed of predominantly high pressure grinding rolls (HPGR) product with a minor component of secondary crushed ore at a combined F80 of 17 mm. The significant reduction in feed size to the SAG mill has markedly changed the operating characteristics of the mill, which has been extensively studied since commissioning in 1998.This paper examines the operation of the 40’ SAG mill in its new configuration in the Concentrator 1 circuit. Operational stability is highlighted as a significant factor in delivering mill performance, which has been achieved through several key improvement projects utilising a theory of constraints framework. Five years of successful project implementation has progressively lifted the maximum processing rate of Concentrator 1 from the design estimate of 2455 t/h to above 3000 t/h. CITATION:Waters, T, Rice, A, Seppelt, J, Bubnich, J and Akerstrom, B, 2018. The evolution of the Cadia 40-foot SAG mill to treat the Cadia East orebody: a case study of incremental change leading to operational stability, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 217–232 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By Pablo Altoé Amorim, Bruno Sellitti Borges, Otávio Lube dos Santos, Arthur Pizetta David, Matheus Diogo Penido da Silva

Automation is in everywhere nowadays, including within companies and industries, and is therefore fundamental and essential for production, quality and process control of them. There are many ways to automate a production line or a machine can be through relay logic, Programmable Logic Controllers (PLCs), and even more modern microcontrollers with native Internet of Things (IoT) support can be used. What are the advantages and disadvantages of each approach? A PCB was created using more modern microcontrollers programmed in C, C ++ and Whiting language to simulate a replacement of a PLC in an actual machine. Having a very positive result, being able to handle the machine manually via Wi fi besides being able to also perform a real-time monitoring of the machine's motors through the mobile phone, thus entering the IoT and fitting into the Industry 4.0.

Oct 1, 2019

By V. T. Dow

In April 1957 the Bureau of Mines instituted a reconnaissance of titanium-and zirconium-bearing heavy sandstone deposits in the Four-State area of Utah, Wyoming, New Mexico, and Colorado. This report summarizes the study. Eighty-two deposits or groups of deposits, containing an estimated 27,920,000 tons of titaniferous sandstone, were examined in the Four-State area; 16 in southern Utah, 19 in Wyoming, 33 in New Mexico, and 14 in southwestern Colorado. The 16 deposits examined in Utah contain an estimated 1,043,000 tons with an average grade of 17.98 percent TiO2, 5.67 percent ZrO2, 20.98 percent Fe, and 0.09 percent equivalent Th02. The 19 deposits investigated in Wyoming are estimated to contain 21,873,000 tons of titaniferous sandstone having a weighted grade of 5.22 percent 702, 0.55 percent ZrO2, 24.8 percent Fe, and 0.01 percent equivalent Th02.

Jan 1, 1961

We outline a first version of an ambitious goal: The world's first horizontal (matrix-independent) generic sampling standard. The specific needs and requirements are overwhelming, as all the world's analytical standards follow strict matrix or material type classification pigeonholes, leading to a plethora of analytical standards. One could rightly expect a similar multiplication regarding sampling standards, yet the singular HORIZONTAL is aimed at being truly generic. Also the existing style of standards writing is cumbersome and partly contradictory. The current work is presently being pursued in CEN and European Union standardisation regimens, for which reason full disclosure and publication is not allowed. Respecting this constraint, we unofficially present selected key issues involved in developing HORIZONTAL: The objective and scope of a horizontal sampling standard is to delineate the minimum set of principles and procedures needed to guarantee documented representative sampling for all types of materials. The horizontal standard is designed for two types of use: 1. auditing/assessing/ improving the reliability of an existing sampling procedure, and 2. design and implementation of a new sampling procedure (new lot type). The principles in this standard are all derived from the Theory of Sampling (TOS), but the standard is far from a mere collection of TOS principles. Representativeness is a characteristic of the sampling process, not of samples themselves. For practical purposes, the horizontal standard follows the fundamental distinction between 'stationary lots' (0-D, 2-D, 3-D lots) and 'dynamic lots' (within TOS aka process sampling - including extended, non-moving 1-D lots). TOS' principles of 'correctness' must never be broken at any stage, lest representativeness is irretrievably lost. The horizontal standard is not written in the mandatory fashion for legally binding matrix-specific standards, eg ISO - for the present overarching purpose a different style had to be developed. The standard must be immediately understandable in full, which merits special demands, eg extensive use of didactic illustrations. HORIZONTAL introduces an all-inclusive sampling variability measure, Relative Sampling Variance (RSV) which is for sampling of stationary lots as variographics is for process sampling - RSV is to be used as a quality criterion for any stationary sampling procedure as applied to a specific heterogeneity (lot/material). The target for this standard is all individuals, companies, organisations and regulatory bodies who are responsible for sampling: technicians, process engineers, laboratory personal, academic and industrial scientists as well as project leaders, technical managers/directors and top managers. Based on current R&D we illustrate the principles promulgated by HORIZONTAL with cases from exploration and mining of minerals commodities, a Finnsh 'Autosampler' at work in the mining context (RSV) as well as sampling equipment for use in the cement and mineral commodities industries. This is an ABSTRACT ONLY. No paper was prepared for this presentation.

Mar 1, 2010

By T. W. Lloyd

Accurately predicting coal seam discontinuities is an important part of modern underground coal mining. Conventional methods of coal exploration sometimes fail to identify rapid variations that may seriously impact mining and quality. Radio Imaging Method (RIM), a geophysical approach to mapping longwall panels, has been developed where electromagnetic signals are transmitted and received though the coal block. The amount of signal loss for a given distance, when compared to the coal seam characteristics, identifies anomalous areas. A comparison of RIM predictions with actual geologic conditions encountered during longwall mining demonstrates the accuracy and usefulness of the data.

Jan 1, 1986

By Steven J. Page

Responding to the increasing concern for dust control in metal and nonmetal mining, the Bureau of Mines investigated typical dust reduction efficiencies of wet bar cutter machines as they are presently being used in salt mines. Wet bar techniques have previously been used in coal mines, achieving dust reduction efficiencies ranging from 11 to 60 pct. Two different wet bar techniques, namely, the front spray and the water trickle, have been studied as they are currently being used in two salt mines. Preliminary results show that the dust reduction efficiencies have a large variation (0 to 66 pct), as is the case for wet bars used in coal. However, whereas wet bars in coal required 3 to 4 gpm water consumption, wet bars in salt obtained similar efficiencies with only 0.1 to 0.4 gpm. The most reliable data obtained during this study show that the front spray system consistently performs at efficiencies between 41 and 66 pct, with an average of 54 pct. The results indicate that, although wet bar cutter techniques in salt mines are a relatively simple and inexpensive means of dust control with a minimum of water consumption, further investigation should be performed to fully evaluate and optimize wet bar cutter dust reduction efficiencies.

Jan 1, 1980

By Henry A. Wentworth

(New York Meeting, February, 1912.) ELECTROSTATIC separation of ores in its present form is generally known as the Huff' process from the name of Charley H. Huff, of Boston, Mass., through whose constant and persistent labors (with the invention of Clinton E. Dolbear as a basis) the successful commercial process embracing separative machinery and the various electrifying devices has been developed step by step, and the finances for the long period of development provided, and the method finally established and recognized throughout the world as an important and successful addition to the ore-dressing department of metallurgy. The permanent field-success of electrostatic separation began in 1908 with a 20-ton Huff experimental mill built specially for the purpose by the American Zinc, Lead.& Smelting Co., in Platteville, Wis., a plant which was a success from the start and was gradually increased in capacity as the market-conditions warranted to 100 tons of concentrates per day. Much credit is due to the above-mentioned company for its initial venture, and for its assistance in applying the process to field use. Prior to 1908 electrostatic separators had been installed and operated (but for a comparatively short time, however) in a number of places; some under the patents of Mr. Dolbear by himself and associates, and some under the patents of Lucien I. Blake and Lawrence N. Morscher, by W. G. Swart, mining engineer, of Denver, who has always been a courageous advocate of electrostatic separation. Due to the difficulties experienced in the generation of the electrical charges, the primitiveness of the separators, the wooden construction instead of iron as at present, the lack of control of the electrical fields and other difficulties overcome by the later inventions of the Huff Electrostatic Separator Co.,

Jun 1, 1912

By J. A. Ressinger

"The purpose of this paper is to discuss some of the differences between various methods of excavating and loading as they relate to mining operations. The intent is not to provide ""pat"" answers, but instead to raise some questions and set forth some reasonable guidelines.Specifically, the paper deals with the differences and relative merits of power shovels versus rubber-tired front-end loaders - or, carrying this further, comparing what could be called ""stationary"" loading or excavating devices to ""mobile"" types."

Jan 1, 1972

By P. R. Jones

A computer program was written for design and cost of a shell and tube heat exchanger in which the total cost, which includes annual fixed charges and annual operating costs, was minimized. The program was written for the type of heat exchanger in which only the tube side pumping costs were significant and for triangular pitch, single or multiple pass, heating or cooling, and no change in phase. Tube diameter was not optimized since the tube dimensions do not affect the cost very much. However, the tube dimensions do affect the shell diameter, number of tubes, and length of tubes; and price optimum design was obtained for four standard tube diameters. Standard heat exchangers having at least the required area are also listed. The program was made adaptable to various fluids and to various tube dimensions by including many of the required data such as physical properties of the fluids, tube data, and standard shell data as input data.

Jan 1, 1969