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By W. C. PAGE

AS the pioneer operation treating the mixed lead- zinc-iron ores from the district tributary to the Salt Lake Valley, the International Smelting Co.'s plant has offered an extremely interesting and instructive opportunity to study some phases of this problem. Basically, there were two main reason for our attempting to work out a successful operation for the separation and concentration of the values contained in the rather widespread deposits of these so- called lead-zinc ores. In the first place, the time was ripe and demanded some method of curtailing the economic waste resulting from the costs of past and present practice of smelting ores of this character, or rather, those ores which could stand the charges inherent with smelting them. Secondly, but rather primarily with us, we believe that such a solution would greatly in- crease in general the production of lead in the district tributary to the Salt Lake Valley. It is generally known that there were and are three relatively large lead smelting plants in the Salt Lake Valley and the decreasing production of correspondingly clean lead ores was not efficient to justify the existence of all three. We could not hope for better lead smelting metallurgy nor more efficient business management than was being practised, so the only prospect was to at- tempt to work out some way to increase the primary production and thus widen the scope of operations.

Jan 1, 1926

By T. T. Tigert

INTRODUCTION THE PURPOSE of this article on methane is to present the simple basic facts of the characteristics, detection, occurrence, and control of this natural gas in metal mines, so that operators and .safety men may deal with it with some degree of confidence. Fortunately, although methane has been noted at many metal mines throughout Canada, the occurrences usually are small flows of short duration, and the ignitions experienced have, in most cases, had minor consequences. However, methane does present a hazard that can be of serious proportions, and ?any complacent attitude toward this gas that might exist in the minds .of people engaged in underground mining operations should be dispelled when it is ,pointed out that, in Ontario alone, ignitions of this gas have resulted in at least four fatalities, and eight men seriously injured and burned, during the past three years. lt is well-known that liberation of methane can and does .occur suddenly, often in mines where no gas has been found before, and that many ignitions and explosions have occurred in so called non-gassy mines. In view of this, it is apparent that no mine can, with any degree of certainty, be classified as non-gassy. CHARACTERISTICS OF METHANIZ The characteristics of natural gas encountered in most of the Ontario mines indicate that methane is the chief constituent. Methane (CH4), commonly termed 'marsh gas', and by the coal miner 'firedamp', is a colourless, odourless, and non-poisonous gas considerably lighter than air, and is the explosive gas frequently found in coal mines. Its physiological effects, closely resemble those resulting from nitrogen.

Jan 1, 1951

By A. Tobey Yu

The smelter is the heart of a copper producing operation. Its principal function is to reduce and convert raw copper concentrates and/or leach plant precipitates into blister copper before it is refined. In addition to concentrates and precipitates, typical feed to a smelter also encompasses matte chips, flue dust, flux and lime. By nature, the characteristics of these materials are extremely variable, ranging from sub-micron to lumps, from slurry to dust, from abrasive to corrosive and free-flowing to adhesive. Furthermore, as a result of geological formation, most of the world's open pit copper mines are located in a semi-arid zone, where precipitation is minimal. This particular climate compounds the problem of handling these materials.

Jan 1, 1976

By O. J. Malacarne

The use of a series of thickeners for-washing of the slime fraction of a leached ore is not uncommon in the uranium industry; however, few ore processing mills have used a thickener circuit for washing leached total ore. The, common, practice is to wash the sand fraction in classifiers and, the slime fraction only in thickeners. At the Uravan mill of Union Carbide Nuclear, Company, a total ore' acid leach is employed to extract uranium values from sandstone ores. These leached ores are then washed at a nominal rate of from 1,000 to 1,300 tons per day in a series of washing thickeners. A typical screen. analysis of the ore being washed in these thickeners, is 25 percent -200 mesh, 3 percent +35 mesh and about, one' percent +l4 mesh., The amount of slimes (-200 mesh) will vary from 20 to 30 percent s the mill receives ore from 150 different mines The washing liquor is acidic, from a pH of about 2 in the first thickener to 0.6 pH in the last thickener and of course ally acid duty equipment must be used. The Uravan mill of Union Carbide Nuclear Company is located in Montrose County, Colorado and is physically located on a canyon wall along the San Miguel river. The thickeners referred to in this, paper are located on top of the mesa above the canyon. For purposes of identification, these thickeners are numbered 1 through 8 from south to north.

Jan 1, 1962

By M. N. Collison

"In 1960, with the opening of the Chisel Lake mine near Snow Lake, Manitoba, the Hudson Bay Mining and Smelting Co., Limited, commenced a new phase in their mining operation -that of bringing ore to Flin Flon over 100 miles of railroad.The schedule of operations required to accomplish this, together with an outline of some of the problems of handling ore at 40° and 50,0 below zero, are discussed. The facilities required to thaw and unload from twenty to fifty cars per working day are also described."

Jan 1, 1966

By D. Beneteau, D. Milne

"Advances in technology provide educators with valuable tools to enhance their teaching and efficiently deliver content to larger audiences. University educators are often encouraged to become more “research intensive” and to increase student enrollment. Faced with these pressures, there is a tendency to use technology to improve teaching efficiencies rather than to enhance existing teaching approaches. Practical learning in applied engineering courses would suffer greatly if hands-on experience is not emphasized. This paper discusses advantages and limitations of new technologies applied to learning, and methods to incorporate more hands-on experiential teaching techniques to applied mining engineering courses.RÉSUMÉ Les avancées technologiques fournissent aux éducateurs des outils intéressants pour rehausser leur enseignement et livrer efficacement de la matière à de grands auditoires. Les éducateurs universitaires sont souvent encouragés à devenir plus « axés sur la recherche » et d’augmenter l’inscription d’étudiants. Face à ces pressions, il y a une tendance à utiliser la technologie pour améliorer l’efficacité d’enseignement plutôt que de rehausser les approches existantes d’enseignement. L’apprentissage concret dans les cours d’ingénierie appliquée souffrirait grandement si l’accent n’est pas mis sur l’expérience pratique. Le présent article discute des avantages et des limitations des nouvelles technologies appliquées à l’apprentissage et des méthodes pour incorporer plus de techniques expérimentales pratiques aux cours de génie minier appliqué."

Jan 1, 2016

By Scott Rosenthal, Dave Gilkey, Theresa Stack, Daniel Autenrieth, Ciara Kremer

Jackleg drill operators are exposed to harmful levels of hand-arm vibration (HAV). Anti-vibration handles and gloves provide modest reductions in HAV exposures and forearm muscle exertion from the use of anti-vibration handles and gloves by jackleg drill operators. The goal of this pilot study was to investigate changes in HAV with the use of anti-vibration gloves and handles compared to forearm muscle exertion experienced by operators and measured with surface electromyography (EMG). Five subjects operated the drill under four different cases: no anti-vibration controls, anti-vibration gloves only, anti-vibration handle only, and simultaneous anti-vibration handle and glove use. Muscle exertion was expressed as a percent of maximum voluntary contraction (%MVC) and was compared using Welch’s ANOVA with Games-Howell post hoc comparisons. The case with both anti-vibration controls in use simultaneously (largest grip diameter) was associated with a mean %MVC of 36.13% during operation for all forearm muscles combined, which was significantly higher than that of the other cases (p < 0.05). There were no statistically significant differences in mean HAV exposures. The anti-vibration handle with anti-vibration glove case only increased the maximum allowable exposure time by 8 min as compared to the control case without any anti-vibration controls. These results suggest that the modest HAV exposure reductions from the use of anti-vibration handles and gloves may pale in comparison to the increased muscle exertion resulting from their use, and this trade-off among jackleg drill operators is a potential concern that warrants further investigation.

Jul 12, 2021

By AIME AIME

NEW YORKERS look forward to the third week of February as the time of the year when they can count on seeing their friends-from far and near gathered in the city for the four-day annual session of the Institute.., Indeed, the metropolitan district is so large that in engineer who lives in New, Jersey and has his office on the lower end of Manhattan island may easily pass a whole year without seeing an acquaintance who lives in Westchester and has an office near Forty-second Street. If the Institute served no other function than to provide a place where friendship may be renewed, ideas exchanged, and new acquaintances made it would still be worth while. But when about 30 technical sessions at which about 160 papers are read and discussed are compressed into four days the annual meeting is also entitled to high rank as an intensive course of post-graduate instruction in the newest development in mining and metallurgical technology. Last, but not least, it is the occasion of a good time for one and all, even if they do get more than a little behind on sleep before the end of the fourth day. Nine o&apos;clock is the time set on Monday morning for the beginning of registration, but a half-hour before that a number have always &apos;put in an appearance, and this is fortunate, because by 10 o&apos;clock four sessions had begun, those on mining methods, geophysics, a round table on the valuation of coal, and the session of the Local Section delegates. Three committees of the A. S. T. M. were also in simultaneous session, so the meeting may be fairly said to have started "in high."

Jan 1, 1931

By Stephen van Duin

As productivity in coal extraction demands increase in underground coal mines, the industry is faced with finding new ways to support production without jeopardising safety. In modern mines the capacity and scale of longwall coal extraction has steadily increased to a point that support processes are failing to keep pace. In particular, roadway development is continually placed on the critical path of activities which maintain mine production, so any inefficiency in this area is quickly exposed. Original equipment manufacturers are under immense pressure to modify their machines to be more interconnected with each other, with machine communication and logistical sharing of space becoming a known requirement. This paper looks at the changing trends in mining practice, analysing available technology as well as currently emerging research into hard automation and discusses the need to integrate machinery and processes in order to see increases in productivity and safety.

Aug 1, 2013

By D. Brandt

The Dos Pobres Mine is a copper oxide heap-leach operation located near Safford, AZ. Mine production is 163 kt/d (180,000 stpd) with a stripping ratio of 2:1. During the startup phase of the mine, the required fragmentation size was easy to achieve as the ore was highly weathered and fractured near the surface. As the mine depth increased, the proper fragmentation size became harder to achieve due to less weathering and different rock types. Because copper recovery increases as crusher product size decreases, achieving the appropriate product size at the crusher is the operating priority. The engineering department began a project to improve fragmentation through blasting and thus increase throughput in the crushing system. It soon became clear that input from other departments was going to be required to make this a safe and economical project. Therefore, the crush and convey and ore control departments worked together to evaluate all available data on blast patterns and explosive loads and tracked performance and results. Using image analysis, drill energy index and databases, improved fragmentation size has been achieved and results have been verified while controlling costs.

Jan 1, 2011

ONE of the largest hard rock operations ever undertaken on the continent is part of the Aluminum Co. of Canada&apos;s gigantic British Columbia development in the mountainous wilderness back of the north coastal port of Prince Rupert. To provide electric power for the huge aluminum smelter under construction at Kitimat, 400 miles northwest of Vancouver, Alcan is reversing the flow of a 5000 sq mile drainage area by blocking the eastward-flowing Nechako River with the largest sloping clay core dam in the world. The backed-up waters of a 110-mile chain of lakes will be tapped at their eastern end by a 10-mile tunnel piercing a mile-high mountain range. From this tunnel water will pass through penstocks to a subterranean powerhouse after a drop of 2600 ft and empty into the Kemano River almost at tide water. A projected battery of eight turbine-driven generators will produce more than a million horsepower, although, initially, three generators of 140,000 hp each will be installed. Power will travel 50 miles across another mountain range, over a glacier, and across an arm of the ocean to what will ultimately be the world&apos;s largest aluminum smelter-a plant 2 ½ miles long. Ore smelted at Kitimat will come from Jamaica, but carving the tunnel, penstocks, and powerhouses cavern out of the heart of a mountain is so vast a job that most of the problems of a major mining operation are encountered. The powerhouse cavern alone is a big hard rock job. This chamber lies 1400 ft back from the mountain face and will eventually be 1100 ft long, 80 ft wide, and an average 118 ft high. Now under construction, the roof of this cavern will take the form of a parabolic arch. The prime contractors, Morrison-Knudsen Co. of Canada, are to excavate a length of 700 ft by May 1954. This section will provide a main control room, erection bay and space for eight generating units. The roof arch is to be lined with reinforced concrete and a plan now under study provides for concrete curtain walls separated from the rock sides of the cavern to prevent moisture accumulation. Cavern Excavation Excavation of the cavern began with the driving of an 8x8-ft exploratory drift 1500 ft long. Two horseshoe-shaped access and tailrace tunnels were bored to serve excavation work. These tunnels are approximately the same length as the exploratory drift and 25 ft high. The floors of both tunnels were graveled to permit the use of rubber-tired equipment. Eventually, the tailrace tunnel will be enlarged to 40 ft height to drain water from the turbine pits below the powerhouse floor. When the tunnels reached the cavern location, a mucking tunnel, approximately 25 ft square, was driven the projected length of the powerhouse at the floor level of the cavern. Another tunnel, 10 ft square, was carried in the same direction from the exploratory drift at the level of the arch spring line, 65 ft above the cavern floor. To connect these two tunnels, seven shafts 10 ft wide and approximately 80 ft long were driven through to the lower mucking tunnel, 65 ft below. These shafts were located on 120-ft centers, the length of the powerhouse cavern. Blasting is done from this upper tunnel to the final line of the roof arch. Two bulldozers, an International TD-24 and a TD-9, doze blasted material to the shafts where it drops to floor level. From here, the rock is loaded by Eimco loaders and power shovels into rubber-tired Koehring Dumptors and Euclid end-dump trucks. The arched roof section will be completely excavated and concreted before vertical blast holes are drilled down from the level of the arch spring line to the floor of the cavern. The arched roof section with its parabolic curve will have a width of 80 ft and a rise to the crown of 47 ft.

Jan 1, 1952

By Doug Harding

The Metropolitan St. Louis Water District’s Project Clear is a 28-year program targeting wastewater capacity throughout St. Louis, MO. The extensive program includes the Jefferson Barracks Tunnel, running parallel to the Mississippi River at 2 m ID and 5,400 m long. A rebuilt Robbins Main Beam TBM began boring but hit challenging conditions about 2,400 m in, including water inflows. A larger 4.1 m Robbins Main Beam machine will complete the remaining 3,050 m in limestone, dolomite, and shale. The TBM will utilize a high-powered, high breakout torque cutterhead along with enhanced 360-degree probing & grouting capabilities to detect any karst formations.

Dec 1, 2022

By John D. Weibmer

A strong step towards acknowledgement of mining as a skilled trade has been taken by the Tintic Division of Kennecott Copper Corp. In May 2 ceremonies, a pilot program was signed into force which, possibly for the first time in US history, recognizes mining as an apprentice trade and grants journeyman status to those who complete the prescribed training sequence. The apprenticeship standards, hammered out after months of consultation between management, labor, and government, are presently limited only to underground hard-rock mining and only within Kennecott&apos;s Tintic Division, but the architects of the program are confident that the concept will spread-first to other underground operations where miners desire documented evidence of their special skills, then to open-pit and soft-rock operations.

Jan 6, 1977

By M. R. Pickus, I. W. Pickus

ORDINARILY age-hardening is thought of as being associated with a limited solubility of one metal in another. Much less has been written about the type of age-hardening that attends the formation of superstructures. Solid solutions generally have a disordered or random arrangement of atoms; that is to say, in a unit cell, such as that of the face-centered cubic lattice, there is no distinction between atomic sites. Atoms of a given metal may occupy cube corners or face centers. Under certain conditions, however, some alloys develop what is known as an ordered structure. In this case, cube corners would be occupied by only one type of atom and face centers by another type, Associated with this ordering process are many interesting changes in physical and electrical properties. Moreover, in many instances the alloys become susceptible to age-hardening. From the evidence now to be described, it appears that age-hardening in 14-carat gold alloys is due to the formation of both a super-structure and a precipitate. Alloys of the metals gold, silver and copper were known in antiquity. The available knowledge regarding their constitution has been ably summarized and extended by Sterner-Rainer,1 Janecke,2 Carter,3 Wise,4 and Coleman.5 Despite the long familiarity with these alloys and the numerous investigations of their properties that have been made, there is still much that remains unexplained. It has been known for a long time that the hardness of these alloys is closely related to the rate of cooling, Similar changes have been observed in the binary gold-copper system,6 one alloy of which corresponding to the formula Cu3Au, has been the subject of a careful and competent report by the English investigators, Sykes and Evans.7 They have established the fact that the shift of atoms from the ordered to the disordered condition takes place in some critical temperature range. At temperatures above the critical range the structure is random, and at temperatures below it the structure is ordered. No difference between these two structures is revealed by the microscope. Both have a face-centered cubic lattice and complete solubility, so that there is no evidence to suggest that the changes in properties are associated with a phase change, The more slowly the alloy is cooled, the higher is the degree to which the ordering process proceeds and the more marked is the increase in hardness. As experimental data were accumulated on 14-carat gold alloys, several contradictions arose. Certain observations tended to confirm the existence of a superstructure, while other observations seemed to be inconsistent with such a transformation. PRESENT INVESTIGATION As a focal point about which to develop this subject, it is expedient to consider first

Jan 1, 1943

By Bob Miller

"All industries have parts and equipment that are exposed to some type of destructive wear. Hardfacing is a cost-effective tool that will minimize wear and increase service life. At first glance, hardfacing can be confusing and troublesome. In reality, it is not.Postle Industries, a manufacturer of hardfacing products, has found that the 22 answers to frequently asked questions may help operators select hardfacing products that are most appropriate for their application. The first 10 questions are addressed in these pages, the full list can seen at Mining Engineering online under the Web-Only Content section.1. What is hardfacing?Metal parts often fail their intended use not because they fracture, but because they wear by abrasion, impact, metal-to-metal contact or some other form of wear, which causes the parts to lose dimension and functionality. Hardfacing, also known as hard surfacing, is the application of a buildup or wear-resistant weld metal onto a part’s surface by means of welding to extend the life of the part. The weld metal may be applied as a solid surface or in a pattern, such as a waffle pattern, herringbone or dot pattern, etc.Hardfacing is becoming increasingly important for many industries to protect equipment that is exposed to wear and abrasion including parts used in mining, earthmoving and construction, oil and gas drilling and steel making and forging. Extending the life of wear parts can save thousands of dollars and improve productivity. Hardfacing can be used to recondition parts that have already been exposed to wear and have lost their useful life, or used in the manufacture of new parts to improve their life before they are put into service.There are three main types of hardfacing applications:• Build-up or rebuilding.• Hardfacing or overlay.• A combination of build-up and overlay.2. What base metals can be hardfaced?Carbon and low-alloy steels with carbon contents of less than 1 percent can be hardfaced. Medium carbon and low-alloy steels are very common since they provide higher strength than mild steels and better abrasion resistance. High carbon alloys may require a special buffer layer.The following base metals can be hardfaced:• Stainless steels.• Manganese steels.• Carbon and alloy steels.• Cast irons.• Nickel-base alloys.• Copper-base alloys."

Aug 1, 2016

Discussion of the paper of Robert Franke, presented at the Butte meeting, August, 1913, and printed in Bulletin No. 79, July, 1913, pp. 1201 to 1205. ARTHUR 0. GATES, Lafayette, Ind. (communication to the Secretary*) :-In connection with the comparison of mechanical crushing efficiencies in Tables I and II of Mr. Franke&apos;s paper, I wish to suggest a somewhat simpler way of making this&apos; comparison, based upon what the writer has called the "crushing-surface diagram," as published by him in the Engineering and Mining Journal for May 24, 1913. Such a diagram, based on the data given in Table II, is submitted herewith, Fig. 1, cumulative percentages being plotted as abscissas and reciprocals of diameters (theoretical mesh per inch). plotted as ordinates.. Such a diagram averages the diameters without calculation, and areas upon it are proportional to surface produced, and, in accordance with Rittinger&apos;s law, to energy spent on crushing alone.

Jan 11, 1913

By Frederick B. Kuhnow

Harmonic energetic delamination a building is being considered for demolition at a formerly known atomic power lab. The building is within a containment structure under a negative pressure, so that no radioactive material is leaked out to the environment. A new approach was developed to make this work possible.

Feb 1, 2020

By H. F. Nash

Coal is the basic necessity of our present-day civilization, and those engaged in the industry, whether miner, day-man, pit boss, tipple boss, superintendent, salesman or operator, have a direct responsibility to the public at large. Our country is blessed with a great supply of Bituminous coal, upon which it must largely depend for its industrial prosperity. Anthracite coal, in its relation to our economic situation, is a small factor, as its ratio of production to Bituminous coal is only about one-sixth. However, within the last ten years, electricity and oil have largely displaced the use of coal in industry, so that the use of Bituminous coal is decreasing, relatively, and the potential production of Bituminous coal has largely increased since the war. High wage scales and high freight rates make the delivered price of coal to the consumer so out of proportion to the cost of electricity and oil -and strikes make the supply of coal so uncertain-that industry is rapidly turning to electricity and oil. The energy in a ton of coal can be transported, by electric current, a distance of 250 miles for 78% of what it costs to ship the coal in bulk, by rail, in the East-and, for about 60% of what it costs in our section of the country. The use of fuel oil, distillate and gasoline, in industry, has increased by leaps and bounds. Especially was this noticeable during the strike this year, as the large packing plants in Kansas City, Omaha and Sioux City (that formerly used nothing but coal) are now practically all using oil. This also supplies to other industrial plants throughout our territory in Texas, Oklahoma, Kansas and Nebraska. Many railroads are using oil, as are also the smelters, cement plants, etc., etc. Ten years ago, 100% of the threshing in the state of Kansas was done with coal-today not over 25% of it is done through that means-and so it goes all along the line. The use of our coal is being yearly more restricted in industry. In the case of domestic consumption, the circle is also ever decreasing.&apos; In small towns and on farms, kerosene, gasoline and wood are largely utilized for cooking. For the past four years, along any country road, it is a common occurrence to hear a buzz-saw cutting old fence posts or timbers taken from creek bottoms. Many thousands of tons of coal are displaced each year through the use of corn and cobs. In larger towns, gas plants have been installed, and many housewives use gas-in communities contiguous to natural gas, that is used for industrial and domestic purposes. The time has gone when industrial and domestic consumers or dealers are satisfied to buy anything that is black-competition among the coal-producing states is keen, and will become more so. Eastern and southern fields are turning out splendidly prepared coals of high quality, and with their lower freight rates to competitive territory, will entirely nullify the use. of our Western coal unless-

Jan 1, 1922

By P Odins

Traditionally, stratigraphic deposits have been represented by a large number of gridded surface and product analytical models, related to each other by naming convention. This approach, though suitable for structurally simple stratigraphic deposits, does not lend itself well to addressing the complex style of stratigraphic deposits which are becoming more prevalent. In addition, the sheer number of individual gridded models involved makes it very difficult to keep a consistent audit trail of the overall deposit model. Recently, a new enhanced block model structure known as Horizon Adaptive Rectangular Prism (HARP) models was introduced to address these issues. An HARP model is specifically designed to allow stratigraphic units to be represented with virtually no loss of structural integrity, by allowing the tops and bases of the individual HARP blocks to ‘bend’ in concert with the input surfaces. By bringing together the best of grid modelling, triangulation modelling, block modelling and grade estimation, the HARP model opens up many exciting new opportunities for the stratigraphic geologist or engineer to take their model further than was previously possible. Examples of improvements in modelling methodology using a HARP model include: the ability to represent complex normal, reverse and thrust faulting; the ability to store thousands of additional analytical, geotechnical or calculated variables in each individual block; advanced visualisation, manipulation and plotting capabilities; and the ability to calculate volumes and resources against complex, three-dimensional (3D) solid pit designs. Finally, several ‘real world’ scenarios, illustrating how this advancement in modelling technology can benefit a wide range of mining professionals are detailed. These examples demonstrate how productivity gains can be made in both long-term resource modelling and short-term ‘week by week’ geological modelling as an adjunct to mine planning.

Aug 22, 2011

Our next speaker this afternoon is a good friend of mine of some years. I must introduce him by way of a little story. Now Harris Sherman, many of you know because he was really in charge of everything to do with the mining industry in the State of Colorado for a good many years. Some of you may know that before he became part of Governor, Lamm&apos;s first cabinet as Director of Department of Natural Resources, he was an attorney for the Environmental Defense Fund and that caused me considerable panic as I think it might have caused some of you. I have observed Hams from the time he stepped into that office until he retired from that office to go into private practice as the senior partner of Arnold & Porter&apos;s Denver office, one of the , nation&apos;s most prestigious law firms. Hams is a Colorado native. He&apos;s lived here all of his life. He&apos;s a graduate of Columbia Law School for his law degree and a graduate of Colorado College down at the Springs for his BA. He has served in state government, but I thought it might be appropriate, since he is no longer in state government, if we used Harris, today, to tell us from a former state official&apos;s perspective what the image is of the coal industry from the seat he held in Governor Lamm&apos;s cabinet for a good many years. He has been the recipient of a number of honors that I think you should know about including Phi Beta Kappa and

Jan 1, 1982