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Studies of the minor element content of sphalerite and pyrite have generally been concerned with individual deposits or localised groups of deposits. However, a small number of more regional investigations have been reported (e.g. Davidson, 1962; Groves and Loftus-Hills, 1968; Loftus-Hills and Solomon, 1967; Price, 1972; Bralia et al., 1979) which have used the minor element abundances to evaluate the petrogenesis and geological affinities of diverse ore types and to fingerprint metallogenic provinces (e.g. Ivanov, 1964). While generally held to be valid, some doubts have nevertheless been cast on the reliability of minor element abundances in petrogenetic deliberations (e.g. Mercer, This paper reports on the distribution of he. Cpl and Mn in sphalerite, and Co, Ni and Mn in pyrite, from sulphide mineral occurrences within the "eugeosynclinal" prism comprising the New England Region of north-eastern New South Wales and south- eastern Queensland (Fig. 1). The occurrences examined are representative of two well-defined styles of mineralisation (Stanton et al., 1974) within which clear patterns of ore-rock distribution give rise to specific metal associations (Herbert. 1977).

Jan 1, 1987

By H. M. Chance

Asst. Geologist, Pennsylvania Geological Survey THE following tables have been compiled from the annual reports of the Inspectors of Mines, to determine the percentages of fatal and non-fatal casualties from roof-falls and explosions of fire-damp. As we cannot assume that every accident has been recorded by the inspectors; as many casualties terminating fatally after the lapse of a considerable period, are inevitably recorded as "non-fatal;" and as clerical errors may have crept into the compilation,* the figures of these tables cannot be considered absolutely correct, but the summary is sufficiently reliable to show the features I wish to differentiate. Under the heading a Miscellaneous" are included all accidents not directly attributable to explosions of fire-damp, roof-falls or falls of coal. Prominent among the numerous causes included under this head are premature or delayed explosion of blasts, accidental explosion of powder or cartridges, accidents from mine cars, falls in shafts, machine accidents, sliding of loose coal in pitching breasts, sltffouration by choke-damp, etc., comprising in all 48 per cent of the total number of casualties. * Compiled by Mr. Maxwell Chapman

Jan 1, 1882

By Don Houston

Vertical crater retreat mining (VCR) requires initiation methods that minimize debris in the borehole. The use of detonating cord and shock tube detonators eliminates debris that could interfere with subsequent loading operations and avoids the cost of using drilling equipment to clear the debris. The explosive must not be sensitive to the strength of detonating cord used, otherwise timing will be affected. “Slicing and Dicing” of product before “Air mailing” down boreholes may facilitate loading, especially in wet holes, and can result in product surrounding the detonating cord. Cord sensitivity testing confirmed that having the detonating cord surrounded by product significantly increases the likelihood of an energetic reaction. Careful formulation and testing, based on a thorough knowledge of the application and the role of ingredients in affecting performance, ensures reliable initiation and avoids cord sensitivity. The use of certain metallic nitrate salts, even in relatively small amounts, was found to significantly increase the cord sensitivity of watergel formulations. Evidence of increasing cord sensitivity includes increasing amounts of damage to product and packaging, to ejection of product from the test pipe, then cracking of the pipe, followed by deflagration then detonation of the product. Predictably, the likelihood of an energetic reaction increases with product temperature, cord strength, and borehole diameter, while it is inversely related to product density.

Jan 1, 2002

By Marlize Barkhuizen, Chris Aldrich

"Owing to environmental constraints, safety considerations and competitive pressures, the development of model-based process control and other automated systems have experienced considerable growth in the last few decades. Reliable process models are usually critical to the successful implementation of these systems. In complex processes, these models are often constructed from process data, as modelling from first principles may not be feasible or cost-effective.Even so, modelling or identification of nonlinear systems from historic plant data can be a daunting task and in the process industries the problem is complicated by the presence of noise from various sources, nonstationarity of the data, intermittence, such as observed in particulate flows, etc. Traditional methods, such as frequency analysis and linear modelling do not handle these systems well. Similar problems arise with the application of nonlinear theory developed over the last few decades, where much of the analysis depends on embedding of the data in a phase or pseudophase space, since these methods were not originally designed to deal with noisy systems.With singular spectrum analysis, the data are embedded in a high-dimensional reconstruction, followed by the introduction of a new coordinate system, where the origin is moved to the centroid of the reconstructed system states and the axes are represented by the dominant principal components of the states (points)."

Jan 1, 2003

By Charles Vaught, Michael J. Brnich, Henry P. Cole, John V. Haley, William J. Wiehagen

Forty-eight workers who bad escaped large underground coal-mine fires were interviewed using an open-ended protocol. This information, and the actual experiences of one eight-person mine-section crew who escaped from a Fire, were used to construct an 18-frame (page) table-top simulation exercise, which was then field tested with 134 miners. The exercise is a research toot that measures miners' proficiency in the information-gathering and decision-making skills related to escaping from a mine fire. It also helps miners to learn and practice these cognitive skills. The exercise was found to be valid and reliable. All miners reported that the exercise was authentic and would help them to remember important information. The exercise total score, and all but two item scores, significantly discriminated among miners with different levels of training. The two items that did not discriminate dealt with whether or not to abandon a helpless fellow miner. When the exercise total score data were pooled, only 13.6% of the miners achieved a desirable score of 90% mastery or greater. The simulation is important because it teaches and assesses critical judgment and derision-making skills that are rarely addressed in miner training. Index Terms- Coal mining, critical skills, decision making, emergency escape and evacuation, escape from fire judgment training, mining, safety training, simulation training, under-ground mine fires.

By D. Harrington

In general, mining is carried on underground, that is, in confined places where it is difficult to obtain adequate lighting and frequently in rock strata requiring much care to prevent caving. Moreover, explosives must be used in mining with the numerous hazards associated with them, and some mines give off explosive or irrespirable gases; also, ma- chinery must be used, usually under conditions much more hazardous than on the surface. These and many other considerations cause mining to be probably the most hazardous occupation in which large numbers of our fellow countrymen are employed. Prevention of accidents in the mining industry is far more complicated than in surface industrial work, even of the more hazardous types, because the different elements that enter into possible accident occurrence are ascertained more readily above ground and suitable action can be taken against them; moreover, errors in connection with prevention of accidents in surface industrial work usually affect only one or, possibly, a few persons, while in zines one human error may readily cause an explosion or other untoward occurrence resulting in the death of scores or even hundreds of persons. This difficulty in the prevention of accidents in and around mines is well-known, and most countries and States have regulations to guard the safety and, to a much smaller extent, the health of workers in mining and allied industries. In general, the State laws and regu- lations regarding the welfare of mine workers are merely a skeletonized outline of some more or less fundamental minimum requirements and are far too general to do much more than suggest some procedure which may or may not be safe or healthful. Most of them are grotesquely out-of-date as applied to present-day conditions, and none of them is adequate to protect life, limb, health, or property. Unquestionably, there is great need for a closer correlation of the laws and regulations of the various States with regard to safety in the mining and allied industries, and while mining conditions vary far too much for a standardized mine safety law applicable to all of the States, on the other hand there are numerous standard and fairly fundamental safety pro- visions which apply to all mines and which should be embodied in the mining codes of all States. Undoubtedly, these standardized safety requirements would be opposed by a consider- able part of the industry, but the ultimate effect would be beneficial to the owners, work- ers, and the general public. For many years progressive mining companies in the United States have not been satisfied to operate only within the meager safety requirements of the State laws or regulations and have adopted additional and far more effective safety procedure of their own, although com- plying also with the State laws and regulations. As a result of this forward-locking policy, zany of these companies have made astonishing progress in the reduction of accidents.

Dec 1, 1935

By Geoff C. Knight

Longwall mining using the shearer is acknowledged internationally as the most economically successful method of high volume production from underground coal mines. Since its introduction in the 1950s, a great deal has been achieved in developing the capability and reliability of the shearer - and the associated face conveyors and powered roof supports - to produce the competent systems now widely deployed. Equipment will continue to improve as knowledge and experience are gained and through the influence of market forces on the international equipment suppliers. However, current systems are so successful that further improvements are likely to be incremental rather than radical unless a high level of system automation is introduced. The automation concept is not new to the shearer-based longwall system. The opportunity and the need were recognized soon after the shearer and powered support were introduced in the 1950s. In the early 1960s, the British Coal Corp. (BCC; then the National Coal Board) attempted remotely operate longwall systems. Those imaginative early schemes were seen as failures at the time. But, with hindsight, a great deal was learned from the experience that stimulated automation research in several European countries. One of the most fundamental lessons learned was that coalface system automation is not possible until there is a high level of competence in automatically controlling the operation of the production machine itself within the coal seam. Once that is achieved, the rest of the system will follow with comparative ease.

Jan 1, 1991

By E Haren, A Winchester

The CSA Mine has a long and varied history from initial discovery in 1871 through to the present. Lead-zinc mineralisation was mined historically near the surface. Today copper and silver are extracted from the deeper regions of the mine. The mine has passed through a number of owners over this time, each with a unique operating philosophy and understanding of the mineralisation. Cobar Management Pty Ltd re-opened the mine in 1999 and has undertaken extensive drilling programs to expand the resource and gain a better understanding of the mineralisation characteristics. Presently mineralisation has been located over a strike length of 1.2 km and to a depth of over 2.0 km with over 30 mineralised lenses from four identified ore systems. The refinement of geological and mineralisation models led to further discoveries and prompted a review and modification of resource modelling processes. Advanced statistical analyses prompted the implementation of ordinary kriging as a grade estimator. Improved stationarity from enhanced geological domaining has been supported by variography and kriging neighbourhood analysis studies. Resource models at CSA are now quantifiable in terms of mineralisation style and estimation reliability. The new techniques are assisting the definition of more mining fronts, which are creating new opportunities to increase mine output.

Jan 1, 2006

By Valentine Garfias

THE various phases of the Mexican oil industry have received so much publicity that there is little to add to the discussion of present and future production, extent and importance of prospective fields, and status of petroleum legislation, to mention but a few of the angles of the Mexican oil problem. However, out of this wealth of information, which is generally of contradictory nature, the average petroleum man is at a loss to know something definite regarding the various questions involved so, keeping the foregoing in mind, it has been the writer's aim to record in a concise form the most reliable and up-to-date information regarding the salient features of the Mexican oil situation. PRESENT STATUS OF MEXICAN OIL INDUSTRY Production During 1921 The Mexican oil fields, during 1921, produced in round numbers 203,000,000 bbl. of which 176,000,000 bbl., or 86 per cent., were exported, the bulk of -these exports, or about 73.3 per cent., going to the United States. The Mexican exports were divided by grades as follows: Light crude, 47.0 per cent.; heavy crude, 22.0 per cent.; tops, 3.5 per cent.; fuel oil from light crude, 24.0 per cent. The balance, or 3 1/2 per cent., includes the bunker fuel shipments and the coastwise trade in Mexico, which is not classified as to grades. The figures show that, in importance, the light-oil fields from about 755 per cent. of the Mexican petroleum industry.

Jan 4, 1922

By A. Meek

This report compares the compressed air driven rocker shovel to the newly developed Warthog Non-throw development end loader. The two machines were compared on aspects such as safety, loading potential, energy efficiency and costs. The objectives of the comparison were to determine whether or not the replacement of the rocker shovel with the Warthog will be operationally and financially justifiable. The results from this study were obtained from underground observations and time studies on the machines, as well as consultations and data collection at the shaft and suppliers. This paper compares only the Warthog loader to the Trident 215 rocker shovel used at Anglo Platinum?s Brakspruit shaft and does not compare the other models of rocker shovels, which are fundamentally the same but will have different loading potentials and specifications. Cleaning times for the rocker shovel are based on underground observations at Brakspruit shaft. These times can be influenced by factors such as blasting practices, compressed air pressure and operator experience and skill. For this reason the times will most likely vary at different shafts. The Warthog cleaning times are based on manufacturer specifications and results from trial stages and therefore further work is required to confirm cleaning times achieved.

Jan 1, 2009

Almost all of the world?s zirconium is mined in the form of zircon (ZrSiO4), the majority as a coproduct of titanium mining from heavy mineral sands deposits. These are placer type deposits, in which the dominant mineral is silica but which also contain a suite of ?valuable minerals,? often consisting of a mixture of titanium minerals, various alumino-silicates and zircon plus a range of other mineral species. The composition of the valuable minerals in such deposits is known as the mineral assemblage. There is no reasonable consistent geological relationship between zircon and titanium minerals. They can derive from separate igneous rock deposits that rarely occur together. The connection emanates once these separate rocks have been eroded by weather and water, often across a very long geological period. Once this has happened, zircon and titanium minerals often find their way to the same locations because they share two major characteristics:

Jan 1, 2011

By E. T. Turkdogan, L. S. Darken, R. J. Fruehan

Further consideration is given to the application of the quadratic formalism to evaluate the thermodynamics of binary metallic solutions from experimental data. The use of the thermodynamic relation, in(r1/r2) dN2= 0, in the evaluation of activity data is discussed. The empirical correlations derived previously for enthalpies and entropies of solutions in Part II are shown to be predicted theoretically for a special case. The applicability of the quadratic formalism to the activity coefficients for binary organic solutions is demonstrated. DARKEN&apos; introduced a quadratic formalism describing the composition dependence of the activity coefficient in the terminal regions of binary metallic solutions. In a subsequent paper (Part II) Turkdogan and Darkeen2 extended this formalism to the enthalpy and excess entropy of binary metallic solutions, and showed that the available data for the activity coefficients and heats of mixing of many solid and liquid binary metallic solutions confirm reasonable applicability of the quadratic formalism. Much variation was noted, however, in the extent of the terminal regions from one system to another, commonly from about 10 to 70 at. pct. For the present purpose, equations derived previously need be given only for one of the terminal regions, e.g. region (I), 0 < N2 < N&apos;2: where subscripts 1 and 2 indicate quantities for components 1 and 2 and superscript ° the values at infinite dilution; other terms are: N = atom fraction, y = activity coefficient, = partial molar enthalpy of solution, ?HM = molar heat of solution, ?Sx = excess partial molar entropy, ?Sx = excess molar entropy. The heat and entropy like terms (constants) el, and S12 are defined in the following expression for the temperature dependence of a12, thus a12 £12 — s12 rnl 2.303RT 2.303 R l J Using this formalism, the thermodynamics of binary systems in the terminal regions may be described over a temperature range of experisental interest in terms of eight quantities: Lº1—Lº2, ?Sx1,?Sxº2 , £12 ,£21,fiai, S12, and S21. In the previous paper, these quantities were evaluated for many solid and liquid binary solutions, and two significant correlations were observed between these thermodynamic quantities pertaining to the terminal regions, thus [10] and [11] Combining Eqs. [9], [l0], and [ll] and rearranging gives a12 -a21 = 1.382R log rº2- 0.08(?S2xº- ?S1xº) [12] Since the second term involving entropies is small and Eqs. 1101 and [ll] are empirical relations, the above equation may be simplified to a12 = 2.74 log rº2 [13] Using the values of a&apos;s and y°&apos;s compiled in Parts I and 11, a12 - a21 is plotted against log(rº2/rº1) in Fig. 1; the line drawn has a slope of 2.74. For Hg-K at 300°C, log(yº2 /yº1)= —5.10, not shown in Fig. 1, and from correlation [13], a12 - a21 = -13.97; this is to be compared with -10.76 derived from the activity data (Part II).

Jan 1, 1970

FRED. MACCOY, Raton, N. M. (written discussion *).-In the review of the Chilean nitrate industry presented by Messrs. Rogers and Van Wagenen, the most critical point relating to the future of the industry has been summed up in the last paragraph: when nitric acid can be produced synthetically cheaper than from the Chilean deposits, the Chilean industry will cease. A study of the prevailing mining methods and extraction process leads one to suspect that much can be done to reduce the present cost of the finished product; and a reasonable reduction of the cost would make available immense reserves of low-grade caliche, the locations of which are fairly well delimited. In a study of costs, one finds that actual data are very hard to procure. The average operator does not know, with any degree of reliability, his "head assay," what percentage of the caliche is lost in mining, nor what tonnage of caliche he is putting into the maquina. One manager remarked to me, "We are not concerned in what it costs to treat a ton of caliche, we are interested only in what it costs to, produce a quintal of&apos; finished nitrate." Apart from the crude methods of mining, and the inefficient work in extraction, attention is at once drawn to the fact that the 40d., stated as the cost of the nitrate at the plant, has become 80d. by the time it is on board ship. Of this 100 per cent. increase in value, 70 per cent. is

Jan 4, 1918

By Franklin Bache

It is appropriate to the place of meeting, and of interest to those members of the Institute whose attention has been more or less directed to Virginia during the past eleven years, to know the result of recent developments of the Virginia coal-field. While, during the late " boom," the attention of the industrial pioneers of Virginia was mainly directed to iron-ore deposits and manufacture, it is safe to say that the coal to which, at that time, comparatively little attention was turned, and which did not directly foster a growth of " boom " towns, will prove the most reliable source of mineral wealth in the State. At the time of the last Virginia meeting of the Institute, held at Roanoke, in 1883, the Wise county coal-field was untouched by a railroad, and its economic existence was scarcely considered. Although, in the meantime, a number of reconnaissances had been made, and a fair estimate of the value of the field formed, it was not until 1891, when the Norfolk and Western and the Louisville and Nashville railroads, respectively, completed their Clinch Valley and Norton extensions to a junction at Norton, Wise county, that any development took place, and not until 1892 were shipments of any importance made. The coal-measures of Virginia are confined to the seven counties of Buchanan, Tazewell, Dickenson, Russell, Scott, Wise, and Lee,

Jan 1, 1895

By G. Ferrara, P. Bozzato, B. Chinè

To obtain a reliable comparison between conical and cylindrical separatory vessels used in dynamic dense-medium separation systems, the following two studies were made: a study of the swirling flow in conical and cylindrical vessels using laser-Doppler velocimetry (LDV) and a study of the behavior of suspensions of magnetite and ferrosilicon in water in both separators. It was found that the tangential velocity profiles differ in conical and cylindrical vessels. In a conical cyclone, free vortex conditions affect the largest part of the vessel, while in a cylindrical vessel, the motion approaches that of a forced vortex, i.e., that of a centrifuge. It was also found that the conical vessel manifests higher centrifigal acceleration and very strong densifying (the density differential) and, hence, the density gradient inside the vessel is large. It was found that the cylindrical vessel manifests lower centrifugal acceleration and low densifying, i.e., low-density differentials, and hence, the density gradient inside the vessel is small. Also, due to greater densifying, the density cut-point in cyclones is higher than the operating medium density, while, in cylindrical vessels, the density cut- point is closer to the medium density. The results provide an interesting description of the differing behaviors of conical and cylindrical vessels, and they help explain the differences in pegormance between the two types of separators.

Jan 1, 2000

By V. Sheikhzadeh, M. Saghaeian, R. Hejazi, A. Abazarpoor

The research aimed to compare the chemical analysis (K, Na, Cl) of Iranian concentrate plants, which are the main source of materials corrosion in the pelletizing plants. Cl alongside alkaline elements (especially K) may cause corrosion and plug in the grate plates and other involved equipment. Therefore, it is tried in the processing plants to remove impurities from the concentrate to prevent potential problems in pelletizing and iron/steel making processes. Part of these impurities are existed in the nature of ores and others are sourced in the processing water. Various samples from the largest Iranian concentrate plants including Chadormalu, Gol-e-Gohar, Jalal-Abad and Sechahun were prepared to investigate the possibility of alkaline problems for each samples. The amount of Cl, K and Na of Chadormalu sample was obviously low and therefore no alkaline problem is expected. The Cl content of Gol-e-Gohar sample was high (980 ppm) while amount of K was less (0.008 Wt. %). Due to low content of K, most of Cl will release as Cl2 or HCl and so problems caused by KCl plugging would not be a problem. The amount of Cl in Sechahun case was nearly same as Jalal-Abad (400-600 ppm), higher than Chadormalu and less than Gol-e-Gohar samples. However, the K content was higher than all samples (0.04 Wt. %). Therefore, the amount of evaporated K would be 2-4 times more than other samples. Since the amount of Cl and K is simultaneously higher than usual iron ores, therefore alkaline problems may be a serious prevention factor for the continuous operation of this plant. In order to solve this problem some counter-measures is suggested and discussed including cleaning system, partial dust enriched with KCl removal and variation in the materials type of involved equipment.

Jan 1, 2018

By José Adilson de Castro

In the integrated steel industries the sintering process plays an important role furnishing raw material to the blast furnace. In this work, a computational simulation of the sinter process is developed that is able to predict the most important phenomena within the sintering bed. The model is based on the multi phase concept with multiple components described by conservation equations of each component coupled with the momentum, chemical reactions and heat transfer. The model validation was carried out comparing the model predictions with averaged industrial data and local temperature measurements within the sinter strand. The model predictions presented good agreement with the averaged values measured on the industrial sinter process.

Aug 2, 2018

By H. H. Hughes, J. G. Dunn, P. G. Fernandez, H. G. Linge

Dissolved Arsenic (As) is stabilised primarily as As(III) and As(V) and enters ground water streams from sources such as the increasing metallurgical processing of As - containing ores [1]. As(III) is more toxic than As(V) and is less effectively removed from solution by oxide precipitation. Even for dilute As(III) solutions, skin contact or ingestion can cause dermatitis or cancer and there are stringent effluent control standards in place for As containing effluent from mining operations [2]. Chemtronics (Perth, Australia) has manufactured a compact digital voltamme­ter, based on anodic stripping voltammetry (ASV) and suitable for use in the laboratory or field. In this paper we demonstrate the utility of this equipment for measuring As(III) concentration with a detection limit of ca. 10 ppb.

Jan 1, 1995

By Kevin L. Purdy

The Process Technology Center of Phelps Dodge Mining Company (PDMC) .operates several test facilities in support of PDMC&apos;s hydrometallurgical operations. Installations for small leach columns, 15 cm. to 60 cm. (6 in. to 24 in.) in diameter, and large leach columns, 1.8 m. (6 ft.) in diameter, are complemented by a test facility for SX/EW operations. The history of and reasons for the development of these facilities: are described and original standard equipment is discussed. A primary goal in constructing these facilities was achieving a high degree of flexibility to allow for testing of new equipment and new leaching and SX/EW technologies as they are developed. Along with this challenge, construction of a filly integrated SX/EW test facility on a small scale brought its own set of challenges.

Jan 1, 1999

Reliably measure stress chan¬ges in order to assess stability of mine openings. Approach: A durable, permissible, sensor and readout system have been developed and tested. How It Works: The stress sensing element is a taut steel wire which is, vibrated at its natural frequency, If the tension on the wire is changed because of deformation of the sensor housing, the natural frequency of the wire changes. This effect is similar to decreasing or increasing the pitch of a violin string by loosening or tightening it. Because the stress sensor electrical output is a frequency signal, rather than an amplitude signal, its accuracy is unaffected by the resistance of the signal wire, or other attenuation. Signal wires can be a mile or longer without affecting accuracy. When a button is pushed on the readout box, the sensor wire is electromagnetically excited and vibrates at its natural frequency. That signal causes a readout in illuminated digits. (By referring to calibration chart and the previous reading, the user knows the change in stress.) This system is permissible. To install the sensor, a slightly oversize hole is drilled into the mine pillar. Next, a special tool is used to both position the sensor and wedge it in place. Figure 1, shows the sensor and its integral wedge and hole-fitting piece.

Jan 1, 1976