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By G. Barbery

In Mineral Processing, the objective of most processes is the separation of mixtures of minerals, which are originally associated in composite particles. Feed preparation processes grinding for instance, which take place before beneficiation or separation processes do not usually break particles at the boundary between mineral phases. They produce composite ("middlings") as well as liberated particle. It is therefore necessary, in a particulate system, to determine the proportion of particles which are liberated as well as, ideally, the size distribution of minerals which remain associated in composite particles. Up to now, there has been a lack of experimental techniques to characterize completely composite particulate systems. Heavy liquid separation which is commonly used to obtain information of this type can only be applied to simple binary cases for which one mineral has a low density (lower than e.g 2.8 ). The technique which is proposed in this paper involves the measurement of parameters on polished sections of particles mounted in a matrix, and the use of mathematical transformations to reconstruct in three-dimensions the information obtained from these measurements .

Jan 1, 1977

By Charles A. Beasley

Coal conversion to electricity or to substitute natural gas requires a significant quantity of natural and human resources including, in addition to the coal resource base, land, water and the construction and operating labor force. Each method of coal conversion has its advantages and disadvantages relative to conversion efficiency, preferred method of resultant energy transportation, resources consumed, and impact on the environment. Regulations which have been passed in recent years to maintain or restore the pre-project environment can add significantly to the capital and operating costs of both a conversion facility and its associated mine.

Jan 1, 1983

By John C. Machisak

THIS INFORMATION CIRCULAR covers the calendar year 1055 and contains statistical data on employment and injuries pertinent to metal and nonmetal mining and to their mills and processing plants that are voluntarily reported annually to the Federal Bureau of Mmes. This report, unlike previous publications, lists not only production and development workers but also office employees associated with mining and milling or processing. The last publication m the series, Information Circular 7798, Injury Experience in the Metal and Nonmetal Industries, 1954, also contains unpublished injury and employment statistics for 1943 through 1953. The Bureau is authorized to request data on injuries and employment from operators in the metal- and nonmetal-mining industries. The information voluntarily submitted by these operators contributes immeasurably to the promotion of safety in the mineral mining industries as it discloses the hazards to which metal and nonmetal workers are continually exposed during mineral extractive operations.

Jan 1, 1959

By Iván Espinoza

El yacimiento de Horizonte es un sistema de vetas auríferas de qz ± sulfuros del tipo mesotermal, que está emplazado en el Batolito de Pataz, un intrusivo Mississipiano localizado en el margen occidental de la cordillera Oriental de la parte norte de los Andes Peruanos. En ese sentido, el presente trabajo describe la exploración geofísica realizada en el primer trimestre del año 2008 en Parcoy, con la finalidad de encontrar nuevas zonas de mineralizaciones potenciales y completar el modelo estructural en la zona. Para ello, se elaboró el proyecto de exploración PD para Parcoy, a través del método IP, el cual es usado en la búsqueda de mineralización de oro, así como el uso de sondajes diamantinos a las nuevas zonas detectadas por la geofísica. Como resultado de ello, se determinó 6 zona anómalas de interés prospectivo para ser analizado por el departamento de exploraciones.

Sep 14, 2009

By Zhou Shu-cai

"A method has been proposed for the pre-treatment of high phosphorus iron ore by carbothermic reduction assisted with microwave irradiation and magnetic separation on a laboratory scale. Chemical analysis of the reduced ore sample, the metal sample and the slag sample were conducted. Based on the above research, the influences of carbon addition, microwave power and microwave irradiation time on the recovery of Fe and dephosphorization were discussed. It indicated that the increase of microwave irradiation time and power had substantial effect on the recovery of Fe while the influence of carbon addition was not obvious and the highest iron recovery ratio reaches some 95.5% when the dephosphorization ratio was 37.68%. A high iron recovery ratio and a reasonable dephosphorization rate were incompatible under the conditions investigated in this study due to the reduced iron and because unreduced P-contained gangues were not efficiently separated. This method may provide a reference for the future utilisation of high-phosphorus iron ore.IntroductionWith the rapid growth of crude steel production in China, the source of iron ore tends to become increasingly strained and is facing the risks of raw material shortage for the iron and steel industry. In order to decrease the production cost, China has to focus on the utilization of its domestic low grade iron ores for the iron and steel plants [1-2]. China has a large deposit of high phosphorous iron ore with a reserve of 7.45 billion tons which is unused in any large scale [3]. Therefore, the development of a successful and economically viable technology for high phosphorus iron ore is of profound importance. To remove phosphorus from the high phosphorus iron ore, several mineral and metallurgical processes have been proposed, such as bio-leaching [4], roasting reduction plus melting separation [5], pre-reduction and screening methods combined with mechanical crushing or air jet milling[6] selective agglomeration plus reverse flotation [7]. However these processes are not cost effective or are time consuming. The traditional pyrometallurgical process( BF+ BOF) refuse this kind of ore mainly because that molten iron is saturated with carbon or high carbon content and thus all phosphor us in the burden goes to the molten iron[8]. Therefore, it is important to exploit the cheap and abundant high phosphorus iron ore as a resource in ironmaking. In recent years, the microwave was widely introduced as a heat resource for extractive metallurgy of iron ore or other minerals. For example, microwave assisted ore milling, microwave assisted carbothermic reduction of metal oxides and microwave assisted mineral leaching issues[9-10]"

Jan 1, 2014

By S. M. Shelton, M. M. Fine, T. L. Johnston

"INTRODUCTION The Bynum property is about 15 miles west of Gadsden and 1 mile north of Walnut Grove, Etowah County, Ala. The ore lies in layers and as irregular masses and pockets in the clay residue from decomposed quartzite and limestone formations to the district.The property has been developed by means of numerous shallow shafts sunk to water level - about 25 foot. Operations are confined to small-scale, selective mining of pockets of high-grade ore. The ore is marketed directly, without beneficiation. The property does not yield a large amount of manganese ores. No estimates of reserve ore tonnages are available.A 206-pound sample was furnished for test. It was taken at random from a stock rile estimated to contain 130 tons of ore. The sample con¬sisted of a mixture of manganese oxides, iron oxides, and siliceous fragments in clay. The manganese occurred largely as soft, unconsolidated pyrolusite and wad. Some hard, crystalline pieces of psilomelane were distributed through the soft material. Small amounts of iron oxides were associated with the manganese oxides. Chert, quartzite, and clay comprised the gangue minerals.Dry analysis of the sample was as follows: 36.0 percent manganese, 6.1 percent iron, 2: .0 percent silica, 1.5 percent calcium carbonate, 0.36 percent phosphorus, 3.0 percent alumina, 2.2 percent barium, and 0.31 percent zinc."

May 1, 1942

By Stephen W. Lambert

The Bureau of Mines examined the wellbore of a vertical gas drainage well in the Mary Lee coalbed to determine the results of specific completion procedures in coal. A jet-slotting tool was used to cut four vertical slots through the casing about 1 ft below the coalbed. Even though stimulation treatment pressure was excessive, hydraulically induced channels were contained entirely within the target coal zone. Sand-filled, induced channels were horizontal, inclined, and vertical, and were propagated in directions similar to bedding planes, rock joint, and coal cleat directions measured in the mine. Variable gas flow rates, recorded during the productive life of the well, were attributed to chronic downhole pump malfunction and the slotted casing below the production zone.

Jan 1, 1978

By T. T. Campbell

This investigation was undertaken by the Bureau of Mines to determine if high-purity ductile molybdenum of uniform quality can be prepared by bomb reduction techniques. Molybdenum trioxide (Mo03) and mixtures of molybdenum dioxide (Mo02) and trioxide were reduced by magnesium in closed steel bomb reactors. Very high pressures in excess of 5,000 p.s.i. developed during magnesium reductions of Mo03. The addition of calcium oxide to the bomb charges caused a significant reduction in pressure. Reaction efficiencies higher than 95 percent were obtained during magnesium reductions of either Mo03 or mixtures of Mo02 and Mo03, but high pressures were encountered when the charges contained from 30 to 60 percent Mo02. Reaction efficiencies were usually low (less than 80 percent) when the bomb charges contained more than 40 percent Mo02. The charges with the best composition considering operating pressure, yield, and purity contained from 10 to 30 percent Mo02. The addition of small amounts of carbon to the reaction charges was helpful because some deoxidation occurred during the reduction and also during subsequent arc-melting of the regulus metal. The purity of the bomb-reduced, arc-cast molybdenum metal ranged from 99.2 to 99.8 percent and in some instances the metal contained as little as 5 parts per million oxygen.

Jan 1, 1962

By Montaser S. EL Salmawy, Takahide Wakamatsu, Eishi Kusaka

"In conventional flotation, fluoride ions selectively would react with the aluminum site on the microcline surface and produce negative charged sites for amine to be adsorbed (Smith, 1976). According to this view, aluminum site is considered as a key feature in feldspar flotation. Generally, fluoride ion has been widely used as a modifying agent in silicate flotation. Since O'Meara's patent appeared on HF -amine reagent system to selectively float feldspar from quartz in 1942, relatively few contributions have been devoted in this issue. The reason might be that the process works very well, and accordingly there is no initiative to investigate in this area. However, due to the awareness of international community to restrict using of hazardous reagents like HF, sound engineering practice to search for alternative methods, not utilizing HF, has been launched. Inspection of literature, one can find several works dealing with this issue.In this contribution, the effect of ethoxylation of long chain alcohols on the quartz and feldspar flotation behaviors was investigated for surfactants of the octylphenol polyoxyethylene family. The tests were carried out with an average of 7.5 (Triton X 114), 9.5 (Triton X 100), 30 (Triton X305), 40 (Triton X 405) and 70 (TritonX 705) oxyethylene units. Electrokinetic and flotation studies on quartz have shown that at low pH values, quartz could be floated with polyoxyethylene octytlphenols. The possible mode of adsorption of these nonionic surfactants may be suggested to be due to hydrogen bonding between the oxygen of ether and hydrogen in the free hydroxyl groups on quartz surface. It was anticipated that the selectivity between quartz and microcline would decrease as oxyethylenic chain length increases."

Jan 1, 2003

By Gordon Lovegrove, Jeffrey Leob, Dwayne Tannant

It has long been known that the combination of aluminum (AL) powder to ammonium nitrate (AN) / fuel oil (FO) can greatly enhance fragmentation or ultimately reduce the number of blast holes in a pattern. Decades of research have meticulously provided optimal AL:AN:FO ratios showing dramatic increases in energy output levels, yet widespread use of aluminized ANFO (ALANFO) has yet to replace the use of ANFO in the blasting world today. This may be due to the perception that the upfront, increased cost of materials deters the selection of this advantageously modified explosive. Researchers have explored this question and promote ALANFO by pledge of massive reductions in day-to-day operational costs. However, in these analyses there is a complete disregard for the external costs of the material; the environmental effects and sustainability considerations of the product. A holistic social cost-benefit analysis of ALANFO shows that an admittedly high-cost explosive does indeed provide an output which contains a wealth of operational savings in typical blast patterns. However, the immediate, on-site costs and savings do not define the limitations of this analysis. A complete comparison of the externalities including the environmental and sustainability considerations of the aluminum by-product life-cycle, and the environmental impacts of both the refinement of ammonium nitrate prills and the acquisition of sufficient fuel oil are also assessed. A savings of $216,000 / year through the use of ALANFO in one particular case study was recalculated to an increase in drilling and blasting costs of $188,000 when the external costs of aluminum, ammonium nitrate, and fuel oil are included analysis. The results of this analysis are intended to improve contractors? selection of explosives by providing additional societal and environmental factors into the equation, in preparation for an exponential global shift to greener business operations, while allowing them to remain competitive.

Jan 1, 2011

By Hon-Yim Ko

1972 constituted the second year of the projected five-year study on constitutive relations of coal. The schedule adhered closely to the five-year outline which is summarized in Table 1. This chapter is intended to serve as introduction and concise synopsis of the year's activities and results, which are presented in greater detail in the following chapters, which have been contributed by the individual researchers in charge of the various aspects of the project under study. Coal Sources, Material Procurement, and Sample Preparation Most of the studies performed during 1972 were done on coal from two sources: the Old Ben Mine #22 in Illinois, and the Bruceton Mine in the Pittsburgh seam of Pennsylvania, which may be considered typical of coal sources of economic importance in the Midwestern and Eastern part of the U.S. These two mines have proven to be reliable suppliers of coal material for our research. We have been able to establish good working relations with their personnel and feel that we can continue to count on their cooperation and help.

Jan 1, 1972

By Richard A. Heckman

Destructive Thermal Technology (DTT) is used in the management of various waste streams. DTT includes Destructive Distillation, Pyrolysis and Classical Incineration. Recent work has more clearly defined the differences in these technologies based upon a more rigorous thermochemical approach. The U.S. Environmental Protection Agency (EPA) has chosen Classical Incineration as the Best Developed Available Technology (BDAT) for the management of hazardous organic wastes. Municipal Solid Wastes (MSW) and Sewage Sludges (SS) are also managed using Classical Incineration. Three environmental problems plague the use of Classical Incineration. Destructive Distillation, on the other hand, avoids these problems. It is an environmentally benign DTT for managing a wide variety of organic waste streams, including hazardous wastes. Thermochemical analysis of the available data on the performance of three types of DTT will be discussed.

Jan 1, 1994

The one hundred and twentieth meeting of the Institute was held at Chicago, Sept. 22 to 26, inclusive, and was in every way success although the steel strike against the United States Steel Corpn. prevented many engineers from attending the steel session and made necessary the annulment of the trip to the steel works at Gary on Tuesday. All of the meetings were held at the Congress Hotel, with the excep-tion of the session on Non-ferrous Metallurgy which was held at the Coliseum where the Fifth National Exposition of Chemical Industries was in progress. This session was a joint one with the American Electro-chemical Society. The total attendance, as shown by the registration, was 850.

Jan 11, 1919

By Alejandro Euribe Dulanto

El presente estudio describe el uso de la palinología y su aplicación a la geología económica. Asimismo, revisa la morfología y la clasificación de las esporas y polen, como la distribución de este por corrientes y la relación de la "lluvia de polen" con la vegetación actual. Se describen también las técnicas palinológicas en la preparación de muestras, los datos sobre la preservación del polen y esporas en los sedimentos, los efectos del intemperismo y la acción que sufren los granos de polen y esporas cuando se les encuentra a grandes profundidades. De otro lado, se narra el establecimiento de zonas palinológicas como los conocimientos sobre los cambios florales, determinando que la evolución es el factor principal que se emplea para las zonaciones palinológicas, aunque las condiciones climáticas y los efectos de sedimentación no generan variaciones en la flora, siendo de importancia en trabajos de correlación local. Finalmente, a través de un ejemplo, se explica la importancia estratigráfica de los estudios palinológicos en el Perú.

Jul 20, 1961

By P .. H. Grimley, N. Champigny

"Fourteen companies (Appendix) representing senior mining organizations in Canada were canvassed in order to assess: (1) the current usage and trends, and (2) the usefulness of computer applications in ore reserve estimation and grade control. The results of the questionnaire suggest that:• computers are unsurprisingly, predominant in the mining industry for calculating reserves and performing grade control;• time and cost savings are realized;• computer-based approaches are applicable to underground situations;• geological information is incorporated to the computerization process; and• computer usage does not hinder the collaboration of geologist and mining engineer.A clear need is identified for case histories comparing computer-calculated ore reserves and actual production data.IntroductionAmong the management and technical staff of some mining companies there is a perception that the application of computer based technology for the estimation of ore reserves and grade control, has as many drawbacks as benefits. Some of the objections raised against the utilization of computers for ore reserve estimation are that:• computer-based reserve models work for large open pit mines but not for underground situations;• computer-generated reserves ignore the geologist's knowledge base; they are strictly a number crunching exercise; and• the use of computers for ore reserves hinders collaboration between the geologist and mining engineer.In order to determine (I) the extent of current computer usage and future trends and (2) whether the objections noted above are borne out by experience, a number of senior Canadian mining companies were canvassed.The respondents were asked to provide:• an assessment of the importance of the computer in the ore reserve estimation and grade control process;• the level of involvement of individuals and staff groups with computer-based ore reserve estimation;• the advantages perceived and realized from the utilization of computer-based ore reserve approaches;• the current and future human resources requirements for the evaluation, implementation, maintenance and development of computer-based ore reserve systems;• the hardware and software resources presently used and planned; and• the developments needed to increase the use and acceptance of computer-based ore reserves."

Jan 1, 1990

By A D. Campbell

Sublevel caving (SLC) is a mining method adopted in a wide range of mining depths and ground conditions with various layouts adopted to suit orebody geometry. Sublevel caving offers more flexibility and versatility compared to other cave mining methods and is a low cost alternative to open stoping. SLC also has the advantage that stopes are not required to remain stable during production, and no backfill is required. This flexibility combined with increasing pressure on mines to target deeper and lower grade mineralisation has led to increased uptake of the method. The implementation of SLC mining methods across a wide range of mining depths and rock mass conditions has led to ground control practices which vary globally from mine to mine. To date, there has been limited documentation of ground control practices in SLC mining and few benchmarks available in the literature. This paper describes the main findings from a global benchmark of sublevel cave mines conducted over three years as part of the Caving 2040 research consortium. The purpose of the project was to document and compare operational practices, technical aspects and hazard management techniques across SLC mines around the world. The review included 21 mines spread over four continents and 17 different mining companies. This paper provides an overview of geotechnical conditions, challenges and ground control practices at each of the benchmarked SLC mines. Mine design and sequencing practices adopted for ground control purposes and hazard mitigation are provided with case studies. The impact of depth and rock mass conditions on mining productivity and development rates is also described.

Nov 29, 2022

By Albert L. Toenges

The Grundy coal field is in process of development, and this circular was written to describe the mining methods and practices in use in the mines now being worked in this field. In lieu of man-hour labor data for individual mines a consolidated sheet of mine costs, which includes expenses for labor, material, and power, is given for all mines. The costs are for a working day only, based on average daily production. Because the demand for coal is seasonal, the costs for idle days, which vary at each mine, have not been estimated. Approximate reserves of coal seams have been estimated from data and maps taken from Bulletin XVIII of the Virginia Geological Survey4/.

Jan 1, 1936

By P K. Singh

Recent advancements in understanding the detonation process are noteworthy, but they are still based on somewhat hypothetical situations. The actual variables that are essential parts of normal blasting practice have not yet been taken into account in such treatments. These include the various initiation practices employed to detonate a column of explosive, from single point initiation to multi-point initiation in blast holes, and the effect on detonation characteristics of both detonators and explosives under multi-deck and multi-hole blasting conditions. The in-the-hole velocity of detonation (VOD) of an industrial explosive is dependent on explosive’s charge diameter and blasthole diameter. The relationship between blasthole diameter and VOD provides a fundamental guideline to the rate of energy conversion and energy release within the detonation front on the interaction of explosives with the confining medium.The in-the-hole VOD of explosives was measured at four experimental sites in India for different blasthole diameters, ie 150 mm to 311 mm, but for identical explosive composition being same particle size, density, viscosity and loaded into blastholes with the same degree of confinement. The results of the studies demonstrated that there is definite relationship in in-the-hole VOD of the explosive and the diameter of the blast hole. The study also confirmed that the explosives initiated with concentrated boosters yielded higher VOD in comparison to those explosives that were initiated with multi-point priming. The measured increase in VOD of explosives for increasing diameter of holes was up to 24 per cent. The rate of change in in-the-hole VOD of explosives increases with increasing blasthole diameter. It can be further stated that the in-the-hole VOD of the explosive reaches a fairly constant value after reaching a limiting/threshold diameter of 311 mm.

Nov 8, 2011

By Maria Olivia de Barros Almeida

O intuito do presente trabalho é identificar, dentre as proporções entre resina e catalisador analisadas cineticamente, a melhor condição de cura. O mecanismo de cura das resinas epóxi é um dos mais estudados e a técnica mais utilizada no estudo deste comportamento é a calorimetria exploratória diferencial (DSC). Neste trabalho, foi utilizado o equipamento DSC 1, fabricada pela Mettler Toledo, pelo método dinâmico. Por meio da técnica de DSC, pode-se observar perfis de cura, temperatura de transição vítrea e a determinação das melhores condições de preparação de compósitos. A reação de cura de resinas termofixas é um processo complexo, definido como uma mudança irreversível nas propriedades químicas e físicas por uma reação química. Estabelecendo-se as condições ideais de cura, a resina epoxi resulta em uma estrutura rígida altamente reticulada, a qual combina as excelentes propriedades térmicas, mecânicas, resistência química.

Aug 17, 2017

The selection of Sydney and Port Kembla for the First Ordinary Meeting of the Institute for 1938 was, no doubt, a recognition of the celebrations marking the 150th Anniversary of the first settlement of this country. In selecting a theme for my Presidential Address, I propose to depart from the precedents of my distinguished predecessors, as I feel that this year of celebration is the natural year for a brief review of the history and progress of the Institute.In July, 1892, the Amalgamated Mining Managers' Association of Australasia held its Annual Conference in Ballarat, Victoria, when Mr. Uriah Dudley, who attended as a delegate from Broken Hill, brought forward the advisability of the formation of an Australasian Institute of Mining and Metallurgy. Mr. Dudley was authorised to take such action as he thought fit, and the result was the formation of a Provisional Committee in Broken Hill of men who were mostly members of the American Institute of Mining Engineers. Broken Hill was therefore really the birthplace of the Institute.A circular headed Broken Hill, September, 1892, with the signature of Uriah Dudley, Acting Hon. Secretary, Provisional Committee, which was sent to those likely to take an active part in the formation of an Institute, read as follows:-The Mining Managers' Association of Australasia has suggested that the time has now arrived when an Australasian Institute of Mining Engineers should be established, having objects similar to the American Institute, of which all of the Thirty-one Colonial...

Jan 1, 1938