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By PHILIP N. MOORE

THE development of the power of the Tennessee River at Muscle Shoals has become a matter of political interest as well as engineering possibility. The controversy over it has been so active that the facts have been obscured, the possibilities exaggerated. Although the members of the American Institute of Mining & Metallurgical Engineers are not generally specialists in hydroelectric development, those who visited Muscle Shoals in October, following the Birmingham meeting of the Institute, were interested, and many of them surprised to learn the actual conditions. These have long been familiar to those who have studied the matter through the reports of the U. S. Engineers on the subject. The approved plan contemplates three dams-No. 1, a low dam close to the City of Florence, planned in the interests of navigation, since the construction of the other dams has rendered impossible the use of the river without it. No. 2-named the Wilson Dam is now under construction. Concerning it political argumentation has waged. No. 3 Dam-much smaller, is planned to be erected several miles above No. 2.

Jan 1, 1925

By John D. VandeKraats

Yielding rock bolt support systems have been developed to accommodate ground movement in shifting ground such as in coal operations; in creeping ground such as salt, trona, and potash; and in swelling ground associated with some clays. These systems, designed to remain intact despite ground movement, should enhance mine safety and help contain costs in areas where rebolting of rigid non-yielding systems is typically required. Four such systems were tested in straight tensile pulls in the laboratory. They include the Slip Nut System from Dywidag Systems International USA, Inc., Ischebeck's bolt mounted Titan Load Indicator, Rocky Mountain Bolt Company's Yielding Cable Bolt, and a rock bolt installed variation of the yielding steel post developed by RE/SPEC Inc. The first two systems are currently marketed products and the latter two are prototype systems. Each system responds to load and displacement by yielding in a unique manner. All are designed to yield at predetermined loads. A description of each system and its yield function is provided. Each system was tested over its prescribed yield range in a test machine. At least five tests were performed on each system. Each system yielded and continued to provide support according to its design. Each shows promise for ground control use in shifting or creeping rock. This work helps to illustrate the comparative differences in performance between these specialized systems and the applications where they may be most useful.

Jan 1, 1996

By Chand F

The silver deposits of Rockvale near Armidale, N.S.W., occur in fissure veins in epi-Permian granite. The ore is fine grained, mineralogically complex, and contains twenty-seven different minerals including eleven silver minerals. The ore is characterized by a unique multiple unmixing from a sphalerite solvent. The following minerals have exsolved from solid solution in sphalerite: pyrrhotite, chalcopyrite, cubanite I, cubanite II (chalcopyrrhotite), valleriite, "brown" stannite, "olive" stannite, argentian tetrahedrite, pyrargyrite, and an unknown grey-white mineral. Several of these minerals derive from a second-stage unmixing, the immediate solvents of which are the products of earlier exsolutions.INTRODUCTIONSmall silver-rich base metal deposits occur at several localities near Armidale in the New England district of New South Wales. Chief among these are the Tulloch Mine and the Rockvale Mine at Rockvale, 27 miles SE. of Armidale, and the Tait's Gulley deposits some 15 miles NE. of Armidale.At Rockvale (Kenny, 1928), irregular lenses of lode material, principally quartz and calcite, occur along a zone of shearing in biotite granite and altered sediments. The orebodies had a maximum width of 6 ft but averaged 2 ft 6 in. The largest lens was 150 ft long and 50 ft high. The Rockvale deposits were worked for both arsenic and silver; 2,897 tons of arsenic were produced but no figures are available forsilver.Little is known of the Tait's Gulley deposits which occur in folded arenites containing small but rich veins of pyrargyrite with base metal sulphides.The sediments in these localities are possibly Silurian.

Jan 1, 1962

By G. L. Oldright

As a rule, the usual zinc retort smelter fired with natural gas made its own burners, of which there might be 300 per block, out of standard pipe fit-tings. The gas was discharged through a feeder pipe at various distances into a cylindrical horizontal "blow hole" through a pillar block and thence into the furnace; the best location of this gas-feeder pipe was at the horizontal central axis of the blow hole; the side entry into the blow hole usually was used. The air entered the same blow hole behind the gas, through a short nipple, in the inner end of which was a constructing orifice in a clay plug; in this ,work cone-shaped funnels of various lengths also were used. Even with the air and gas correctly proportioned to each burner, small differences in their dimensions were found to influence greatly the temperatures reached, their uniformity, and consequently the percentage of zinc extracted. This fourth paper of a series on cooperative work in the zinc retort plants of the Eagle-Picher Mining & Smelting Company discloses the methods and principles followed in approximating closely the optimum dimensions for various burners, with examples from experimental and commercial furnaces showing the interrelation of such dimensions with combustion and temperatures in the furnace.

Jan 1, 1948

By Christine Hansen

?Kiss my Asteroid? Unofficial Title Human life is tied to minerals It?s worth noting that: The living human body consumes minerals. The minerals we take in multivitamins show the close linkage between human beings and mineral resources. Unlike tourism or specialized manufacturing, a human being could not live without mineral consumption. Minerals and their consumption is a tangible part of human life.

May 1, 2013

By R. Bauer

Adaptations and redesign of the existing already very successful and proven road milling machine concept and technical innovations such as an optimized, specifically for mining application developed cutting drum, cutting housing design and cutting tools, high manoeuvrability achieved via a tight turning radius, a three disk clutch system and a cutting drum drive that allows for the acceptance of higher loads, a complete reinforcement of the chassis to withstand higher vibrations and torque, the installation of increased engine power via a modern drive unit, a specifically for mining/construction applications developed operator’s platform and finally a redesigned air intake system and the adaptation of the levelling system resulted in far more cost effective and advantageous capabilities of Wirtgen Surface Miner in soft to medium hard mining and construction applications. As the achieved results show for the first time in modern surface mining history mechanized cutting is capable to compete successfully against traditional drill, blast/ripping and other conventional mining methods.

Jan 1, 2007

By J. R. Thoenen

The enormous and constantly increasing demand for limestone to supply a multitude of uses is a remarkable feature of the mineral industries. As approximately 130,000,000 tons of limestone are produced annually, it is not surprising that deposits at or near the surface are gradually being exhausted and that less advantageous supplies are being worked. Quarries are becoming deeper and wider year by year, and in many places the volume of overburden that must be removed to allow open-pit work has increased alarmingly. Quarrymen are also gradually learning how expensive it is to sort and clean stone from a deposit overlain by poor material. As such conditions confront the limestone industry, the natural tendency is to seek some modification in method whereby the handicaps of increasing cost may be met and overcome. Operators, some of them unwillingly, have been forced to conclude that underground work in drifts and tunnels is the most logical solution of the problem. The unwillingness of some is largely due to unfamiliarity with mining and to the unfounded fear that costs must increase and dangers multiply when mining is undertaken.

Jan 1, 1926

By A. J. Kauffman Jr.

The Petrographic Section of the Bureau of Mines, Northwest Electrodevelopment Laboratory, Albany, Oreg., annually examines thousands of minerals and rocks. Samples are received from mining, engineers, prospectors, and government agencies, both State and Federal. During the past 2 years certain uncommon minerals have been identified in the samples submitted. Eleven occurrences have been selected for reporting in detail. These selections were made because in most cases a new locality is involved. The data reported are the result of application of the latest techniques, and widely disseminated references concerning each mineral have been added for completeness. Several occurrences have been described by other investigators; in those cases new data have been supplied to supplement the already published information on these occurrences. No uranium-bearing minerals have been included; they will be treated in another paper. The Bureau of Mines does not make chemical analyses or assays for individuals or firms In direct competition with private laboratories. Mineral¬ogical examinations, however, are made for prospectors and the general public. Such examinations a call surface to determine whether the sample in question has possible commercial value. If it has apparent value, the sender is so informed, and suggestions as to its .Arc, development and marketing are offered. The latest scientific apparatus is available to aid in identification. The apparatus includes microscopes, both wide-field and polarizing, a Bunsen-type spectroscope for visual observation of the Zinc and band spectra of many elements, differential thermal apparatus for the examination of hydrous material, apparatus for cutting and mounting either thin sections for study in transmitted or polished surfaces for reflected-light studies, and a high-intensity magnetic separator for concentrating minerals according to their magnetic susceptibility. Also, available, but not an integral part of the Section, are several laboratory-type Geiger counters, a grating spectrograph, and X-ray diffraction apparatus. If need be, all of these tools may be employed to identify a mineral or rock.

Jan 1, 1950

By Francesco Montanari, Gianni Schena

"Recent improvements in X-ray computed tomography allow investigation of objects several tens of millimetres in dimension with spatial resolutions in the order of a few microns. These improvements are made possible by coupling the micro-focus technology adopted by some of the latest cone-beam X-ray sources with an increase in the efficiency of the detectors. The micro-focus technology allows the production of clearer images at high magnification by reducing the penumbra (fuzziness) associated with larger focal spot size.Even higher resolutions can be expected in the next few years with the commercialisation of nano-focus X-ray tubes. In practice one can inspect a system of fine composite particles and analyze the different mineralogical phases in each individual particle. Computed tomography allows accurate liberation studies, e.g. providing liberation spectra or washability data in tens of minutes. However, on-line application of micro-focus computed tomography is unlikely in the foreseeable future, despite rapid development.Dual-energy (DE) radiography is another X-ray technique, which allows retrieval of the volumetric content of valuable components in two-phase particles in a fraction of a second. A digital radiograph of a single two-phase particle produces a grey level image, where the luminosity of the pixels is determined by the sum of the attenuation levels of all the structures. Thus morphological and compositional effects concur to produce the radiographic image, which does not allow retrieval of the composition of the particle, as the 3D-structure of the particle is compressed into a 2D-image, with an obvious loss of information. Thus, in principle it is not possible to discriminate between thick, comparatively penetrable, and thin, comparatively impenetrable mineralogical components."

Jan 1, 2003

By Arnaud Faucher, Claude Bazin, Marilène Renaud, Mohamed Mai Manga

"Grinding circuits are operated in the presence of disturbances due to ore changes and equipment malfunctions. One of the challenges faced by the operators is the detection of a disturbance, the identification of its origin and of the action needed to minimize its impact on the process. Hydrocyclones overloading, worn or partly plugged apexes of the units of a nest, surging and internal liner detachment may cause a loss of classification capacity and quality. Recovery losses in downstream leaching or flotation circuits justify the effort in developing techniques for the detection of hydrocyclone malfunction. Two approaches for the detection of hydrocyclone fault are presented in this paper. The first proposed method uses the conventional sensors available in a grinding circuit allowing real time detection of hydrocyclone abnormal operation. The second technique is based on the use of vibration sensors installed on the hydrocyclone of a nest. This last technique enables the classification of the hydrocyclone malfunction as surging, overloading and plugged apex. The two techniques can be combined to increase the robustness of the problem detection.INTRODUCTIONHydrocyclones are used for many purposes ranging from water separation, fines removal and obviously for the preparation of the feed for subsequent concentration circuits in a mineral processing plant. The strategic role of the hydrocyclones for the preparation of the feed to the concentration circuit is often underestimated because of their simplicity of operation and robustness (Napier-Munn et al., 1996; McIvor, 1988). It remains that despite their simplicity, hydrocyclones have been studied extensively from 1970 to 1990 with the objective of developing mathematical models of their operation to be incorporated into grinding circuit simulators (Napier-Munn et al., 1996; Lynch, 1977; Flintoff et al., 1987). Such a development effort is already an acknowledgement of the importance of these units in a mineral processing plant. Several authors (Del Villar et al., 1996; Plitt and Kawatra, 1979; Casali et al., 1998) proposed soft sensors to estimate the classification efficiency of hydrocyclones using sensor measurements. However, few of the proposed sensors are used in the industry. More recently several papers were published to discuss the application of 3-D modelling of the hydrocyclones (Narasimha et al., 2005; Cullivan et al., 2004) and sensors (Bond et al., 1999; Neesse et al., 2003; Hou et al., 1998; Olson and Waterman, 2004; Williams et al., 1995; Willams et al., 1997) to help in the detection of hydrocyclone malfunction."

Jan 1, 2010

By J. F. Barkley

To reduce fuel consumption in industrial and commercial fuel-burning plants throughout the Nation, cooperative efforts of thousands of individuals are required. These individuals are scattered over the country and hold various positions in thousands of independent establishments. To accomplish as much as possible on this problem during the Second World War, it was decided that personal contact with fuel users was absolutely necessary; publicity, although an important factor, could not by itself give satisfactory and needed results. It was planned to have qualified engineers visit commercial establishments to go over with them the problem of reducing their fuel consumption. The specific plan, toward which all efforts aimed and around which the rest of the program revolved, consisted in brief of 1. Conference of visiting engineer with management to obtain cooperation. 2. Appointment by management of a plant employee as fuel "waste chaser." 3. Work of engineer with "waste chaser" and, if appropriate, with plant operators on most efficient operation of equipment.

Jan 1, 1948

De acuerdo a los últimos trabajos realizados sobre la exploración en la mina Cercapuquio, se realizó un muestreo de la veta 53 donde se observó que en la caliza, más allá del ala norte, como en el lugar llamado Chaupirange, existe grandes depósitos de carbonado estático con siderita y limonita, en bolsa de erosión de la caliza normal. Asimismo, se describe otros métodos utilizados para la exploración geofísicadel subsuelo como los electromagnéticos e inducción. En ese sentido, se trata de crear un campo (primario) a través de una corriente eléctrica alterna (primaría) en un circuito. A este campo, es concadenada una corriente (secundaria) que circula en el cuerpo conductor mismo ( en general desfasada respecto de la primaria), que genera a su vez, un campo secundario. Este último se compone con el campo primario para formar un campo total, que está relacionado con la posición y naturaleza del cuerpo conductor que funciona de circuito secundario.

Jan 1, 1956

By G. S. Pauley

Paper presented at a meeting on: Artificial intelligence in the minerals sector, held in Nottingham, UK, 20 April 1993 (original title: Case-based reasoning can be a catalyst for improvement). A new computer software technology known as Case Based Reasoning (CBR) can be used to produce small decision support systems that are economically viable. This is because the knowledge that they contain can be owned and maintained by their users. A CBR tool has been used to perform a pilot study with Anglesey Aluminium Metal Ltd. The results are encouraging. They suggest that a combination of CBR and participative design and implementation techniques (such as Checkland's Soft System Methodology) can achieve sustainable improvement in mineral processing functions. An explanation is presented of why traditional, rule based systems are often an ineffective way to implement support systems. It is shown that CBR may provide an appropriate technology solution. Methods of achieving sustainable benefit are indicated. The pilot study with Anglesey Aluminium Metal is used as a practical illustration of the development of a CBR application. A review of potential application areas and some observations about the implementation are presented

Apr 1, 1994

By J. H. Bain, D. C. Haigh, L. C. Parsons

Jan 1, 1964

WHEN the writer resided at Zeehan, qn the West Coast of Tasmania, some years ago, he took a keen interest in the geology of the district and availed himself of the opportunity to investigate occurrences, of the varied minerals in which the field abounds. The following notes were compiled as a result of one of his periodical visits to the outlying mining districts, when an examination was made of the bindsay Reward tin mining property, which has an area of 140 acres. This is most easily reached from Renison Bell, the centre of the North Dundas tin-fields, on the Emu Bay railway, 'about' eight miles north east of Zeehan. Thence a pack track some 14 -miles long connects with the mine, crossing the Piemah River by a fine suspension bridge.The mine itself is situated on the main south leading spot of the Parson's Hood Range, at an altitude of some 1600 ft. above sea level. The Parson's Hood Range is composed of granite and is an extension of the rugged Meredith Range. A remarkable feature is the uniform topography of the surrounding country when viewed from the peaks. Except where dissected by the rivers and creeks, the surface is practically level and, indeed, affords a striking illustration of an ancient uplifted peneplain.The mine has been opened by means of trenches and adits, and the ore-body proved to extend for a length of 30 chains, with an average width of about 100 ft. Its general trend is west-north-west, and its dip, which is steep, corresponds to that of the country-rocks. These latter, which are of sedimentary origin and generally regarded as of pre-Silurian age, have been tilted at high angles, consequent, no doubt, on the crustal movements produced by the intrusion of the huge granitic masses which now form the high ranges in the vicinity.It may be here remarked that it is not Within the scope of this paper to deal with the sequence of events leading to the geological structure...

Jan 1, 1923

By T. A. Rickard

Freeman, the English historian, said that he had learned from Macaulay "never to be afraid of using the same word or name over and over again if by that means anything could be added to clearness or force. Macaulay never goes on, like some writers, talking about `the former' and `the latter', `he', `she', `it', and `they', through !clause after clause, while his reader has to look back to see which of several persons it is that is so darkly referred to". He might have learned also from Macaulay that a preposition makes a' feeble ending for a serious statement. How often do you hear `the former' and `the latter' in conversation? Good conversation is a guide not to be dis¬dained. When you must use `the latter', do not confuse it with `the last'. Cheap labor, cheap fuel, and cheap transport are essential, the latter [last] being particularly important in base-metal mining. The apparatus may be used to determine such gases as hydrogen sulphide, chlorine, oxides of nitrogen and some others, as well as sulphur dioxide. In the case of the latter two, etc. The two last mentioned are "sulphur dioxide" and "some others". He should have stated which two, and he should have avoided that wretched phrase "in the case of ". Pinning may be partly prevented by use of chalk, oil, or turpentine. The latter [last] is best. I "Partly prevented" is a poor phrase. `Prevented! is a word that does not lend itself readily to modification. He means `checked' or `corrected'.

Jan 1, 1931

By C. S. Wageman

Staying competitive in the highly aggressive Powder River Basin is a challenge facing all operators. Any advantage that a mine utilizes to improve productivity and reduce costs could mean the difference in the tight spot coal market. Technological advances in mining equipment and data acquisition at the Eagle Butte Mine in Gillette, Wyoming result in productivity gains and increased maintenance awareness. A new overburden haulage truck fleet with an onboard payload and fault monitoring system interacts via telemetry with the loading shovel and PC's located in production and maintenance offices, enabling staff to monitor production and maintenance on a real-time basis. This paper will describe the system and highlight the benefits realized as a result of its implementation.

Jan 1, 1996

By W. J. Birch, R. Farnfield, S. Hosein, C. Johnson

Modern smart phones include accelerometers based on MEMS (Micro Electro Mechanical System) technology giving the possibility to measure both acceleration and orientation. The widespread use of such phones has driven technological development to such a degree that it is now possible to obtain a triaxial accelerometer unit, that also include signal conditioning and analogue to digital conversion, in a package smaller than 1 cm2 (1/2 sq.in) for a relatively low cost.

Feb 6, 2023

By Sven Reutzel

Investigations show that Co-based melts embedded by glass flux in a crucible can be under- cooled nearly as strong as samples processed containerlessly by electromagnetic levitation. This allows to measure magnetic susceptibility on undercooled melts while combining the use of a Faraday-balance and undercooling technique. The magnetic susceptibility of Co and Co-based alloys (such as Co-Pd and Co-Cu) is investigated as a function of temperature from superheated to undercooled state. This is done by measuring the change of magnetic force F, on a sample in a constant magnetic field Bo and an additional gradient field by means of a Faraday-balance. When liquid Co-based alloys are undercooled the magnetisation steeply rises if temperature approaches the Curie temperature. The magnetisation is measured for some Co-based alloys in liquid state as a function of alloy system and its concentration. The results show that the magnetic susceptibility of the liquid undercooled samples follows a Curie-Weiss behaviour, from which Curie temperature and magnetic moments for the liquid state are inferred.

Jan 1, 2002

By J. Philip Neal

Feldspar is no example of special mineralization in isolated spots: it can usually be found within a mile or so of almost anywhere. Along with silica sand, it is a major part of our world's total mineral composition. This fact imparts to it an economic status different from a sulfide ore, or potash, or phosphate. While every feldspathic "stringer" does not possess economic potential, the generous distribution does yield a high statistical frequency of good feldspar ore bodies: the adjective "good" being subject to some flexibility of interpretation. The strong chemical bonds of this alkali aluminum silicate give it certain use advantages, but under present technology its individual elements cannot practically be separated to create aluminum, potassium, sodium, silicon - or their oxides. Its present uses rely upon chemical inertness - as in fillers; and on its physical melting characteristics and their effect in glass, enamel, or ceramics.

Jan 1, 1973