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By J. E. Spurr

"Zinc Industry in BelgiumBy March F. Chase, Consulting Metallurgist, Bureau of MinesBelgium for many years was the principal spelter producing country of the world. Gradually its production was surpassed by that of Germany, and Germany in turn lost first place by the production in the 77ti.tad States. For the ten years previous to 1914, 21.6 per cent of the world's spelter was produced in Belgium. Of this production approximately 40 per cent was exported. A large percentage of the balance was rolled and of the shoots thus produced a considerable quantity was also exported.From an economic standpoint even before the war, the Belgian industry was in a unique, if not praoarious, position. Dependent upon foreign countries for ore and foreign markets for sale of products, smeltor was at a distinct disadvantage when compared with some of those of other localities. These disadvantages were partly offset by cheap coal and labor and by whatever there is of value in experience and what we may term for want of a better expression smelting tradition. However intangible this latter may be, it did have and has today an influence on commercial operations.One must not overlook the effect it will have on the revival of the industry. It may not be the determining factor but the fact that for so many years this industry flourished in Belgium, and played such an important role in the industrial life of the country will decide many operators to attempt to re-establish their operations.In 1913 the Belgian spelter plants produced 204,220 long tons of spelter or approximately 20 per cent of the world's production. During this year 500,000 to of ore were treated. The actual value of all of the products derived from treating sine ore amounted to 225 million frames."

May 1, 1919

[ ] Granville S. Borden (Mining Taxation, P. 1049) has written two other published articles on the subject, Taxation and Mineral Resources, and An Income Tax Program for Mineral Producers. Both articles appeared in Mining Engineering. He is presently employed by Standard Oil Co. of California as a special tax counsel. He holds an LL. B and an LL. M from George Washington University and a Bachelor of Science in Mining from the University of California. He has been chairman of the Taxation Committee of the Minerals Economics div. of the AIME. Borden fishes, plays golf, prospects, and performs mineral analysis as hobbies. [ ] Charles C. Towle (co-author, Uranium Deposits of the Grants District, New Mexico, P. 1037) graduated from the Colorado School of Mines with a degree in Geological Engineering. He was a member of Sigma Nu; Theta Tau, an honorary professional society; Blue Key, honorary social society; the glee club and quartet, and a member of the student council. He has been a mucker, driller, flotation operator and mill shift boss for the Clear Creek-Gilpin Co., Idaho Springs, Colo.; Geologist, chief engineer, and chief geologist for Patino Mines & Enterprises Consolidated, Inc., Bolivia; appraisal engineer and part-time geology student, Denver; office geologist for Geology Dept., special Engineering div., Sea Level Canal Studies, Panama Canal; and geologist, div. of Raw Materials, USAEC, Grand Junction, Colo. He is currently chief of the Denver Exploration Branch, div. of Raw Materials, USAEC, Denver. Towle was at one time a tournament golfer, playing three and four times a week. While working in South America he played in numerous tournaments. Today, although playing only occa sionally, he shoots in the low eighties.

Jan 1, 1952

By Alfred C. Lane

WE recently received from Professor A. C. Lane, Emeritus Professor of Geology and Mineralogy, Tufts College, Mass., and a Corresponding Member of this Institute, a very interesting account of some recent developments in radioactive methods of determining the age of minerals and, therefore, of the rocks in which they occur. It deals in particular with studies of the minerals of certain pegmatite dykes on the Huron claims and Bear claims in southeastern Manitoba, which, the results indicate, are among the oldest rocks of the earth's crust. The following article presents a non-mathematical summary of Professor Lane's paper . . It will be noted that he is anxious to obtain suitable samples of certain minerals and rocks for further age studies. We hope some o our members may be able to supply him with the material he needs. It may be well to explain briefly how the age determinations are made. Uranium is continually breaking down, or disintegrating in successive steps through radium, etc., to a final product which is lead (uranium-lead), and the rate at which this change takes place is known. Minerals containing uranium will therefore contain lead also, and the lead-uranium ratio mul-tiplied by a certain factor (approximately 7 ,600) will give the age of the mineral in millions of years. Thorium also disintegrates at a known rate to give lead (thorium-lead) as a final product, and the age of a mineral containing thorium can thus be calculated from the lead-thorium ratio. Thorium breaks down more slowly than uranium. In unit time, one gram of thorium produces about as much lead as 0.36 grams of uranium.-ED.

Jan 1, 1938

By M. J. Shulman

An algorithm used by the US Coast Guard to find lost objects is utilized to optimally allocate exploration efforts during initial stages of an exploration program. Based on classical search theory, the algorithm assumes a target probability distribution function, a detection function, and a cost function. The three functions are analogous to delineating areas of possible mineralization, choice of exploration methods, and exploration budget. Application of the algorithm is shown for a hypothetical target distribution. Using the maximum number of field day available as the cost function, the optimal allocation of effort is shown for different exploration methods, e.g. electromagnetic survey and induced polarization. The adaption of the algorithm for the exploration process is discussed.

Jan 1, 1984

By M. G. Rylatt, G. M. Popplewell

"Production from Canada's first diamond mine is planned for the last quarter of 1998. The climatic conditions and the variation in kimberlite types to be treated have lead to the development of a compact and flexible processing plant.High kimberlite moisture contents and winter temperatures below -40°C have dictated a process flowsheet with limited in-circuit storage to reduce materials handling difficulties. The latest developments in High Pressure Grinding Roll technology will be used to liberate the valuable diamond, reduce diamond breakage, and increase fines production to reduce the amount of material for down stream processing in the Heavy Medium Separation section.A varying heavy mineral concentrate yield has lead to the development of a final Recovery section that will incorporate Attrition Milling and Wet High Intensity Magnetic Separation for concentrate reduction. The latest developments in diamond X-ray sorting will be used to produce a final diamond concentrate for mechanical sizing, weighing and packing.Fine tailings thickening will utilise Deep Bed Compression type thickeners. This relatively new technology can produce;i) high underflow densities at low flocculant dosage rates, andii) clear overflowswith a smaller thickening area than conventional high-rate thickeners."

Jan 1, 1998

By George H. K. Schenck

INTRODUCTION Boom-type miners mechanize the cutting and loading of a solid face of rock having a compressive strength as high as 124 MPa (18,000 psi). These machines differ from continuous miners in that they can cut much harder rock for any given cutter-motor power. In addi¬tion, a boom miner is more flexible, selectively cutting any cross-sectional configuration from circular to square arched faces, 1.57-rad (90°) turns, and mixed faces. The basic operational concept of these machines, utilizing a rotary cutterhead mounted on a slewing boom, gained importance in Europe during the 1960s, where, due to their specialized use in roadway development in coal mines, they were called roadheaders. Along with continuous miners, boom miners share the ability to fully mechanize the cutting and loading of rock, while eliminating the need for explosives and the shattering and overbreaking of roof and rib rock that is normal with conventional mining methods. The machines are crawler-mounted and most have a gathering-arm load¬ing system that, moves the cut rock onto an internal chain conveyor, subsequently discharging the rock into a transport device such as a shuttle car or a bridge conveyor. Light- to medium-weight boom miners are cutting softer rocks and minerals successfully, including coal, shale, rock salt, potash, phosphate, weak sandstones (e.g., those associated with uranium ore), and other softer ores such as iron. Heavy third-generation ma¬chines have extended rock cutting to much harder ores such as borate, oil shale, and almost all rock associated with coal seams, except for the harder sandstones and limestones. The mention herein of specific manufacturers, brand names, or models is made by way of example only and does not constitute endorsement by the author or The Pennsylvania State University. All costs cited herein are in 1977 US dollars. TYPES OF BOOM MINERS All boom miners utilize drag bits fixed on a rotary cutterhead that is powered by an electric motor mounted in the slewing and elevating cutter boom. The cutter¬head is either a ripping or a milling type, and the machines have evolved through three generations (Boldt, 1977). As shown in Fig. 1, only one boom miner cur¬rently produced can use both ripping and milling cutter¬heads on one machine. Table 1 lists boom-miner models built in large num¬bers and/or successfully used or marketed in North America. Table I excludes machines of which only a few have been produced and none sold in North America, such as those manufactured by Demag, Eick¬hoff, Paurat, and Thyssen-Rheinstahl. The only Ameri¬can boom miners are the F-16 and Super ROC¬MINER"', manufactured by AEC, Inc., State College, PA. Machine Generations Three generations of boom miners can be distin¬guished according to their times of introduction, their rock-cutting abilities, and their weight classifications. Fig. 2 illustrates typical best-practice production rates possible from boom miners for selected cutter-motor power sizes (other power figures can be interpolated). Productivity is related directly to the energy applied to the cutterhead and indirectly to machine weight; higher

Jan 1, 1982

By M. A. Alan

The Bellavista Gold Deposit lies 75 Kms north west of San Jose, the capital of Costa Rica, Central America and 3 Kms north east of Miramar, in the Province of Puntarenas. The total road distance from San Jose to the deposit is 120 Kms all paved road except for a 2.5 Km graded, gravel road on the property (Figure 1). Infrastructure services in the Miramar-Puntarenas area are well developed with electrical power distribution, a modern port facility and community services being available. The deposit lies on the south west flank of the Tilaran Mountain Range between an elevation of 550 and 800 meters above sea level. The local topography is steep, originally covered with pre-montaine, tropical wet forest vegetation which has been largely destroyed due to clearing for cattle grazing. The annual rainfall is approximately 2,950 mms, 90% of which occurs between May and October.

Jan 1, 1992

By D. G. Kesterke

Research was conducted to determine the feasibility of extracting elemental oxygen from silicate-bearing melts by high-temperature electrolysis. The method was based on a modification of existing processes for electrowinning metals from their oxides dissolved in molten halide systems. Electrolyses were performed at temperatures ranging from 1,050° to 1,250° C in boron nitride cells that incorporated a silicon carbide cathode and an iridium anode. The electrolytes contained volcanic scoria as the oxygen source, plus mixtures of BaF2 and LiF as fluxing agents. Cell gases containing almost 14 volume-percent oxygen were obtained. The average anode current efficiency for several experiments of extended duration was calculated to be 55 percent. Cell design and operating conditions are described, and some of the problems associated with the process are discussed.

Jan 1, 1971

By John F. Blandy

IT is not my intention in this article to consider this subject in the light of the geographer or geologist, but rather in that of the mining engineer, and to endeavor to show the necessity and value to him of studying the minor details of the field or district in which he may be engaged. I t has been said by a distinguished geologist that "the natural boundaries of the geographer are rarely described by right lines. Whenever they occur, however, the geologist may look for something remarkable." And again : " Physiognomy is no idle or doubtful science in connection with geology. The physiognomy of a country indicates almost invariably its geological character." Our country furnishes examples enough of the truth of these remarks, and in no part of it is it so beautifully illustrated as in our own State, which has been so ably described by Prof. Lesley in his admirable little work on the "Topography of Coal." As the great mountain lines become guides to the geologist in determining and mapping out the geography of the formations, so do the minor details of topography become guides to the mining engineer in conducting his explorations, discovering of dislocations, and determining the character of the deposits which are the object of his search. I t is therefore requisite that he should, whilst making his surveys, pay the strictest attention to every variation of the landscape and surface of the ground. Until he has mapped out every feature he may be unable to read the geological changes which may have

By means of top-slicing methods, wide veins, masses, or thick beds of soft ore may be mined, where the caving of the overburden is of no consequence. The ore is mined in a series of horizontal floors or slices, taken in descending order, from the top of the deposit. Each floor is mined in small sections, the roof of each section being allowed or forced to cave before an adjacent section is attacked. The method as used in two mining districts—Marquette, iron, and Pachuca, silver-gold—is described in the two papers following:

Jan 1, 1925

By J. Zollinger, J. R. Kennedy, E. Bouzy, B. Rouat, D. Daloz

"Ni-based superalloys have been replaced in the last low pressure stage of jet turbines for aircraft by titanium aluminides. In order to improve the properties of these Ti-Al alloys and extend their usage deeper into aircraft engines grain refinement by inoculation has been investigated. Borides are the most common inoculants for Ti-Al alloys, however they form brittle particles which are detrimental to the final properties of the alloy. Inoculants manufactured from a Ti-Al alloy with refractory metal additions were proposed to alleviate the issues arising from inoculation with brittle particles. An alloy was chosen which had less than 10% lattice mismatch with the alloy of interest (Ti-46Al) to maximize efficiency. Initial experimentation showed a decrease in as-cast grain size by a factor of 2 between the inoculated and non-inoculated samples along with an absence of the brittle particles found with boron inoculations. Investigations into the interaction between the inoculants and the melt were also carried out to better understand the inoculant size distribution and efficiency upon solidification.INTRODUCTIONTitanium aluminum alloys are an interesting material for aerospace applications. Their high temperature oxidation resistance and high specific strength make them particularly promising (Kim & Dimiduk, 1991). Recently, titanium aluminides have replaced nickel based superalloys in the last low pressure stage of the GEnx turbine engine. In order to increase their usefulness in turbines their properties must be improved for high temperature (>800oC) applications. Grain refinement is one method to improve the properties of a material, however current methods of grain refinement of Ti-Al alloys by inoculation have significant drawbacks. A new method of inoculating Ti-Al alloys by using Ti-Al alloys with small refractory metal additions (Nb, Ta) has been developed to avoid the drawbacks of current methods while still being effective grain refiners."

Jan 1, 2016

[Adams, E. R Rock Springs, Wyoming Adams, V. H. 422 East San Miguel Street, Colorado Springs, Colorado Allen, Earl W 257 Rio Grande Street, Salt Lake City, Utah Allen, Louis B . Box 1920, Denver 1. Colorado Allen, Thomas Argonaut Hotel, Denver, Colorado Alston, G. L Mine Safety Appliances Company, Pittsburgh, Pa. Ambler, J. B Box 591, Denver, Colorado Apperson, A. B. 394 Elm Street, Denver 7, Colorado Arnett, L. L. 325 North First West, Price, Utah Audin, Abel Somerset, Colorado Audin, Clement, Jr Paonia, Colorado Audin, Clement, Sr Box 627, Paonia, Colorado Audin, Ralph Box 285, Somerset, Colorado]

Jan 1, 1952

By A. Singh

"Flotation of fine (< 10 µm) minerals is a challenge exacerbated by the emerging practice of fine grinding flotation feed to better liberate targeted minerals; however, the ability of conventional flotation cells to float liberated fines remains questionable. The Gold Ore solution using Mach reactors was tested at Mintek, South Africa, and showed an ~180% increase in the Kelsall kfast factor, a projected recovery improvement of 4% for the Mach-reactor case, and final concentrate grade twice that of conventional flotation. Theory, pilot plant results, and key aspects of plant design, supplemented by operational plant observations after commissioning, are discussed.RÉSUMÉ Le procédé de flottation de minerais fins (< 10 µm) pose de grandes difficultés, lesquelles sont aggravées par la pratique émergente de l’alimentation du circuit de flottation avec des mailles de broyage très fines pour mieux libérer les minéraux ciblés ; la capacité des cellules de flottation classiques à flotter les fines de minerais libérées reste cependant discutable. La solution proposée par la société Gold Ore, qui utilise des réacteurs Mach, a été testée à Mintek, en Afrique du Sud ; elle affichait une augmentation d’environ 180 % du facteur kfast développé par M. Kelsall dans son modèle de flottation, une amélioration prévue de la récupération de 4 % dans le cas du réacteur Mach, et une teneur finale des concentrés deux fois plus importante que celle obtenue avec la flottation classique. Sont débattus dans cet article la théorie, les résultats générés par l’usine pilote ainsi que les principaux aspects de la conception de l’usine complétés par des observations relatives à l’usine en activité après sa mise en service."

Jan 1, 2018

The first production on the Island of Trinidad was discovered 29 years ago; 13,275 acres were proved for oil and gas to the end of 1937, and 145,076,700 bbl. was produced from 2661 wells, or 10,928 bbl per acre. The production of oil in 1936 was 13,237,030 bbl. and in 1937 a new peak of 15,498,350 bbl. was reached. During November 1937, the daily average production was 43,350 bbl., or 35 bbl. per well, while the maximum gas production was 45 million cubic feet daily. Two hundred fifty wells were completed during 1937 and 15 abandoned. At the end of last year, 800 wells had been temporarily shut down, 1235 were producing oil and gas, and 2 were producing gas only. Six hundred seventy-nine dry wells had been drilled to the end of 1937. At the end of November 1937, the following oil-producing methods were in use: 395 wells flowing, 491 pumping, 97 on air-gas lift and 252 wells miscellaneous. There were no flooding operations. The oil is produced from the Miocene and Eocene and is of both asphalt and paraffin base. The gas produced averaged approximately 1050 B.t.u. per cu. ft. with 0.8 gal. of gasoline per 1000 cubic feet.

Jan 1, 1938

By Kenneth M. Berrry

A unique situation has developed at an abandoned coal mine in St. Clair County, Illinois. Subsidence features have been observed at the ground surface over the mine including settlement of a pair of bridges for Illinois Route 158. The Illinois Department of Transportation (IDOT) is currently replacing the two bridges. Foundation treatment for the two new bridges included backfilling the mine void. The light rail system for St Louis (MetroLink) is also constructing a bridge over the same abandoned coal mine less than 1000 ft from the Route 158 bridges. The new MetroLink bridge is being constructed using piles which extend through the coal mine and overlying bedrock in order to transfer the loads to below the mine floor. The differing foundation types for the IDOT and MetroLink bridges were due to geometry and economic factors involved with the individual structures.

Jan 1, 2001

By Michael J. Beus

This Bureau of Mines report describes a tunnel stress relaxation gage (TSR) developed to measure initial radial displacement around full-sized underground openings. The TSR technique was shown to be a valid concept in previous field verification tests. Sensitivity has been improved by employing a titanium alloy cantilever in the transducer head, which also permits a deeper sensor location. Use of improved fabrication methods such as stainless steel bellows and sputtering techniques and use of an environmental chamber for testing greatly increased overall reliability. A miniature data acquisition system (DAS) was interfaced directly to the transducer for increased versatility and containment entirely within a borehole. The present TSR system is suitable for use around full-size underground excavations, particularly machine-bored openings. Field evaluation of the improved instrumentation verified the design goals.

Jan 1, 1978

Silver and gold bearing ore from the Palmarejo mine, located within the Mexican state of Chihuahua, contains a complex mix of electrum, native silver, silver sulfides and silver chlorides. This paper presents a case study that describes the selection, development and engineering of a tailored process plant for the recovery of silver and gold from this ore. Process circuit feasibility study modelling, metallurgical test work and engineering studies are outlined. Options considered to optimise the recovery of the contained silver and gold are compared, based upon cost, operability, recovery and engineering aspects. Concentration by flotation was found to be the preferred primary recovery route. Intensive leaching of the flotation concentrate resulted in solution grades sufficient to allow direct electrowinning to be evaluated against the more traditional Merrill Crowe process. The flotation tailings stream is processed through a separate leaching stage as there is sufficient economic metal extractable from this stream. The processing flow sheet, which is designed to maximise the recovery from both the flotation concentrate and tailings, and to utilise a common metal production facility, is presented.

Jan 1, 2009

By Katri Avarmaa

Aluminum and copper are large volume metals in electronic appliances, while tin and indium exist as common minor elements. All of these non-ferrous metals are aimed to be separated and recycled from the end-of-life electronics into non-ferrous scrap fraction(s), and further through pyrometallurgical and/or hydrometallurgical processes to pure metals. Depending on the mechanical pre-treatment processes, aluminum and copper liberation from each other varies. This study focuses on the influence of alumina on indium and tin distributions between copper alloy and iron silicate slags with 0, 9 and ∼16 wt% of Al2O3. The experiments were executed with an equilibration-quenching-EPMA technique in an oxygen pressure range of 10−10–10−5 atm at 1300 °C. The metal-slag distribution coefficient of indium remains constant as a function of alumina in slag, while that of tin increases. Therefore, aluminum in feed or alumina addition to the slag improves the recovery of tin into copper. Nevertheless, oxygen pressure has clearly more significant influence on the behavior of both the metals in the smelting conditions.

By D Maconochie, S Pradhan, M Reed

The Waterview Connection will provide a high-quality strategic alternative to State Highway One and complete Auckland’s Western Ring Route connecting State Highways 20 and 16. The project includes twin three-lane motorway tunnels 2.4 km long and 13.1 m internal diameter (ID). The tunnel construction started in November 2013 using the tenth largest earth pressure balance (EPB) tunnel boring machine (TBM) in the world. The tunnels will pass beneath urban and greenfield areas as well as a major local arterial road. The project is being delivered by an alliance of constructors, designers and the New Zealand Transport Agency. This paper describes some of the key innovative and cost saving design solutions that have been achieved through collaboration in the alliance environment with the construction team, owner’s verifier, the segmental lining precast suballiance and the M&amp;E suballiance for the underground works. The key design elements of the tunnel comprise a three-lane roadway, invert culvert and backfill, precast segmental lining, sixteen mined cross passages including a low point sump cross passage and steel segments for opening to the cross passages. This paper reviews interdisciplinary design integration and the economies achieved in the permanent works tunnel lining design, including reduction in lining thickness and optimising reinforcement, cross passage separation of 150 m, efficient design of the invert culvert and backfill design, main drainage pipe and low point sump. The paper also describes the attributes of the TBM and the invert culvert construction methodology.CITATION:Pradhan, S, Maconochie, D and Reed, M, 2014. Tunnel design in an alliance for Waterview Connection, New Zealand, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 425–430 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By Gabriel Zarate

Mantoverde is a heap leach-SX-EW plant that was commissioned in December 1995 at a production rate of 42,130 tonnes of copper per year and 5.4 million tonnes of ore per year. Copper production was steadily increased reaching a maximum of 62,239 tonnes in 2012 for an ore throughput of 10,5 million tonnes. In order to get these production and throughput rates, a number of changes have been made in the metallurgical parameters of the plant operation since the start up, among them particle size, heap height, acid addition distribution in curing and leaching solution, leach cycles and pad type. Most of the modifications have been implemented after carrying out extensive column test work programs. The modifications implemented and the results obtained, as well as the test work programs carried out, are discussed in this paper.