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By Numan Elmas

Barite deposits located in Dinek and surrounding region have important economic features with their large reserve capacity for Turkey. The objective of this study is to elucidate geological and depositional characteristics in terms of. site investigation and chemical analysis. In order to do this, geological area of about 300 km2 was examined and detailed geological map was constructed. It was observed that Barite mineralization in these deposits was occurred in carbonate and pelitic rocks of Lower Cambrian-Lower Ordovician. Deposits were exposed to advanced diagenesis regional metamorphism and tectonics that rotated and deformed the barites; therefore, barites shows secondary veins, brecciate and fracturing structure. Even though, a few light isotope values of barites may suggest hydrothermal and exhalative sedimentary characteristics or possible mixing with magmatic fluids, generally heavy isotope values indicate that the sulfate ions were supplied from coeval seawater and, many of sedimentary features and petrological, geochemical characters support dominantly sedimentary origin.

Jan 1, 2005

By L. Adler

INTRODUCTION The purpose of this paper is to describe in engineering terms the singular and basic operational kinematics of all excavating and bulk handling equipment. The safe and efficient use of equipment will be fostered by enabling the engineer to conceptually duplicate the operators' "tasks" in directing and controlling it. A simple graphical and notational scheme will be introduced to define the essential gross repetitive motions. The significance of this effort includes filling a vital analytical gap at the work face, and in establishing direct communications between the engineer and equipment operator. Since all types and sizes of earth- moving equipment are covered, a major concern has been to integrate equipment specialties into d single encompassing discipline. Equipment types are closely related to the working conditions, and their selection and evaluation are also considered. The extension to human factors analysis is natural and predictable. Since human [actors are involved, the operational analysis can also be considered a catch-all for many subtle vagaries. BACKGROUND Symbolic modelling linked to a notational system will be developed and intensively used. This constitutes the "language of science," providing a shorthand method which gives immediate recognition, is fluent, explicit, reinforcing, unequivocal and provides limitless associations. Many examples of symbolic modelling exist in chemistry, physics, the military, engineering sciences and it is a major tool in mapping. Its use is so ubiquitous that it often goes unnoticed. On the other hand it must be realized that something is lost in simplifying and idealizing what is an extraordinarily complex occurrence. The components describing the basic operational kinematics of equipment include: (1) the vehicular motions as a rigid body and (2) the job-end motions focussing on excavating (Adler, 1985). These provide all of the components in the load-haul-dump sequence (L-H-D) , and will yield three dimensional expressions. Complex patterns can also be assembled from these simple elements. An existing equipment designation employed in earthmoving will be integrated into this approach (Carson, 1961). Along with the basic motions, corresponding working conditions will be noted.

Jan 1, 1986

By Huaiyang Zhou

"Hydrothermal systems are a major component of the processes that shape the composition and structure of the ocean crust, providing a major pathway for the exchange of heat and elements between the Earth’s crust and oceans, and a locus for prolific biological activity on the seafloor and underlying crust. On the other hand, the structure and composition of hydrothermal systems are the result of complex interactions between heat sources, fluids, wall rocks, tectonic controls and even biological processes.Ultraslow spreading ridges, including the Southwest Indian Ridge and the Gakkel Ridge, are most remarkable end member in plate-boundary structures (Dick et al., 2003), featured with extensive tectonic amagmatic spreading and frequent exposure of peridotite and gabbro. With intensive surveys during the last decades, it was suggested that ultraslow ridges are several times more effective than faster-spreading ridges in sustaining hydrothermal activity. This increased longevity can be attributed to deep mining of heat and even exothermic serpentinisation (Baker et al., 2004).Distinct from faster spreading ridges, one characteristics of hydrothermal mineralization on seafloor in ultraslow spreading ridges, including the active Dragon Flag hydrothermal field at 49.6 degree on the Southwest Indian Ridge, is the abundant and pervasive distribution of lower temperature minerals (such as Fe-silica or silica, Mn (Fe) oxides, sepiolite, pyrite, marcasite, etc.) in the hydrothermal fields. Structures formed by lower temperature activity in active and dead hydrothermal fields can also be identified. High temperature minerals such as chalcopyrite are rare or very limited in hydrothermal chimneys at ultraslow spreading ridges. The distribution of diverse low temperature hydrothermal activity is consistence with the deep heating mechanisms and hydrothermal circulations in the complex framework of ultraslow spreading tectonics. On the other hand, deeper and more extensive mineralization at certain locations along the ultraslow spreading ridges can be reasonably presumed."

Sep 1, 2014

By D. DeGagné, E. De Souza, J. F. Archibald

A comprehensive survey of minefill practices in underground mines in Canada has been conducted. The survey was designed to cover the entire filling operation for individual mines from feed to the preparation plant, to underground transportation, and to stope placement. The questionnaire examined such areas as mining method utilized, the purpose of backfilling, backfill formulations, including binding and chemical additives, slurry properties, transportation parameters, stope preparation procedures, backfill placement properties, fill instrumentation, and costs. This paper presents the current state of backfill usage in Canada, identifies trends in minefill practices and provides mine operators with an updated database to compare their own practices with modern trends throughout the industry.

Jan 1, 2001

By Werner Burger, Marcus Lübbers

TBM development in recent decades has been dominated by increased face pressures, larger diameters and multi-mode functionality paving the way to realize projects deemed impossible before. In addition, the trend towards digitalization does not stop at the tunnel portal. A shortage of skilled personnel and the ever-present wish to increase workplace safety, quality and system performance automation, operatorassist or even autonomous systems have become key development targets. The paper will present the current state of the art in light of these special conditions.

Jun 13, 2023

By Leonard Sargeant

The Pocahontas Coal Field consists of eight mineable seams of low-volatile coal in southern West Virginia and Virginia. The deeper seams, especially the Pocahontas No. 3 and No.4 Seams, under heavy cover and below drainage are notoriously gassy. Methane in the Pocahontas Field is generally thought of as being confined in the coal itself, rather than in mud slips or clay veins. Furthermore, it is characteristic of Pocahontas coal to retain its gas until the coal is broken and removed from the solid. Because of this inability for gas to escape from unmined coal, entries developed around large blocks are seldom of significant value in bleeding off methane before pillar extraction begins. This is evidenced by the fact that it is not uncommon to find gas liberated during the mining of chain pillars and barriers which have been developed for several years. The Pocahontas Fuel Company develops almost all solid coal by conventional methods with shuttle car haulage. To provide the maximum productive capacity without compromising ventilation and safety requirements, the Company has adopted standards for ventilating 5, 6 and 7-entry sections.

Jan 1, 1960

By Andrew W. Jenike

There used to be a time when bins were designed for total volume and placed in any available place of the plant. Poke holes were provided and feed was maintained by manual prodding, lancing, hammering, and by various mechanical flow-profiting devices. Little thought was given to what occurred inside the bins and why materials did not flow. Indeed, such mental effort was hard to justify while low-cost manual labor was plentiful, quality standards low, and rates of feed moderate. The past fifteen years have seen a drastic change in these conditions. We all know that labor for hard manual work is becoming unavailable at any wage, level. Standards of product uniformity are continuously rising. This uniformity is just as important in a fine ore feed to ball mills as it is in a cattle feed or in a flour mix. Rates of feed now frequently exceed 2,000 tons per hour per feeder. At that rate there is no time for, lancing or prodding. An efficient storage, plant contains a known available volume of bulk solid, and feeds it at the required time, at the prescribed rate, and without degradation of the product. A storage bin may also perform other functions such as blending of different grades, degasification of aerated, powders, isolation of different gaseous media. A contact bed of particles flowing by gravity in counter-current with a gas or liquid may be used as a continuous reactor. Gas or liquid pressures can be simply contained by, a sufficient head of flowing solid.

Jan 1, 1968

By J. Y. Kim

Lead ions originating from galena during processing of complex sulphide ores migrate to "cover" the surface of sphalerite and iron sulphide mineral particles, and cause poor selectivity in differential flotation. Generally in sulphide ore processing, the lead-activated minerals float in the Cu/Pb rougher circuit. Subsequently, surface lead complicates the zinc flotation circuit by lowering the concentrate grade due to the co-flotation of lead-activated iron sulphide minerals. The effect of lead in the differential flotation of sphalerite from Cu-Pb-Zn and Pb-Zn ores is discussed. Plant and laboratory test data are interpreted by determining the surface composition of individual grains of sphalerite and iron sulphide particles using two surface analytical techniques, Laser Ionization Mass Spectrometer (LIMS) and Time of Flight-Secondary Ion Mass Spectrometer (TOF-SIMS). Cationic and anionic species on the surface were analyzed to elucidate the phenomena.

Jan 1, 1995

By H. Mitri

A new monitoring device called SAFEBOLT (Stress And Force Evaluator in BOLTs) has been recently developed at McGill University. The device is essentially an alternative to the load cell, it permits the monitoring of bolt axial load in the field. The SAFEBOLT system consists of a portable readout unit, a connecting cable and the SAFEBOLT device, which is installed in the bolt head. The new device can be installed on any industry standard rockbolt or rebar. The device is completely encapsulated in the bolt head, which makes it resistant to corrosion, rugged, and free of any electric wires. Pilot tests at two underground Quebec mines were carried out and helped improve the initial design of the device head.

Jan 1, 2002

By Raja V. Ramani, Wilson Miola

The potential health effects of quartz-bearing airborne dust in mine and mill atmospheres point to the need for the quantification of quartz content in the source material for determining the source-sink relationships and for choosing applicable control measures. While a standard method exists from a regulatory point of view for the sampling of coal mine atmospheres for determining (i) respirable dust concentrations and (i) the amount of quartz in thesamples, there is no generally accepted standard method for quartz analysis in bulk samples of coal and host rocks. Generally, the bulk sample is reduced to a powder for producing quartz analysis samples. Extensive controls are necessary to ensure representativeness of the analysis samples when these are very minute fractions of the bulk samples. Since the amount of analysis sample is not limited, alternative methods for quartz analysis may also be tried. It is, however, necessary to adopt a procedure which will satisfy several statistical requirements to guarantee representativeness of the quartz analysis samples. In this paper, the important factors in the preparation of quartz analysis samples from the host rocks and bulk samples are discussed. The method developed to prepare the analysis samples is outlined. The results of application of the procedures are presented. The procedure developed for quartz analysis sample preparation is based on sound statistical foundations. The procedure has been validated for reproducibility and homogeneity.

Jan 1, 1991

By R. K. Singhal

In 1990, Canada produced 69.4 million tonnes of coal of which some 65 million tonnes was produced by surface mining methods. The two Western Canadian provinces, Alberta and British Columbia produce approximately 55 million tonnes of coal by surface mining. These two provinces also provide the bulk of the metallurgical coal for export. The geological conditions in the Western provinces particularly in the mountain region are complex. The coals are friable and the seams are steeply inclined, sheared, intensely folded and faulted. There may be as many as 15 to 20 coal seams present with true thickness ranging from 2.5m to over 8m. Most of the Canadian surface mines are large (over one million tonnes per annum) using modern mining equipment such as shovels, high capacity trucks and draglines. At present the industry is going through another of its up and down cycles but has continued to make impressive gains in productivity. This has been achieved through greater mechanization, better management practices and a will to succeed in a highly competitive world market. This paper presents an insight into the current status of the Canadian Coal Industry and essentially updates the information given by the authors at previous SME meetings.

Jan 1, 1992

By S. G. Malghan

Steel consumption forms a significant part of the operating cost of a minerals processing plant. An estimated one-quarter billion kilograms of steel in the United States and over one-half billion kilograms in the world are consumed each year in wet grinding alone. The depletion of ore grades and the necessity of finer grinding of abrasive ores are expected to increase the steel consumption even higher. Through continued research and development by the mining industry and the suppliers of steel products several remedies to reduce steel consumption have evolved. This paper critically reviews the mechanisms involved in steel wear, and currently available methods, materials and operating conditions for reducing steel consumption. Particular attention is given to liner design modifications and substitution of steel liners with rubber liners.

Jan 1, 1981

By R. F. Shurtz

This paper uses a simple model to illustrate the fact, widely known to information theorists, that the covariogram represents only half the information in the data used to construct it. It suggests and illustrates methods of putting the other half to use in describing mineral deposits. It also identifies applications in which the phase information is not needed.

Jan 1, 1986

By Stephen H. Partney

Waste clay ponds are a necessary part of phosphate rock beneficiation. They are large, averaging 2.6 km2 (1 sq mile). They are unsightly in that they protrude 6 to 15 m (20 to 50 ft) above natural grade. Stabilization and reclamation is slow and they have had a history of catastrophic failure. Florida has never published a specific rule regarding the configuration or height of these ponds. But it has enforced several policies along these lines. The phosphate industry has been forced to make major monetary decisions that affect mine economics for decades. The Florida Bureau of Mine Reclamation believes that the direction of regulation has been solidified but changes are still anticipated. Phosphate rock has been mined in Florida since 1890 (Fig. 1). Three notable technological changes occurred in the industry that led to major shifts in mining technique and volume. By about 1915, hydraulic mining had been replaced by centralized washers. Hydraulic mines usually started at an outcrop in or adjacent to a stream of the pebble zone. Water was pumped out of the stream through high-pressure monitors and sand and clay were washed away from the pebble. Mobile grizzlies and screens were used in conjunction with animal and human labor to concentrate the pebble and haul it away. Populations were sparse and the clays washed into the stream were considered an acceptable price for the commerce. The clays were not voluminous because the pebble zone typically contained relatively small amounts of them. Machines largely replaced animals by 1910 and provided greater efficiency of production. Centralized washers replaced mobile trommels. They allowed greater ease of access to shipping routes by rail. Some clays were placed in mine cuts from 1915 to 1930. Some were dammed off to increase the capacity of a given site. Some of these also failed, leading to clay plumes that were visible all the way to the Gulf of Mexico. By concentrating the waste clays (slimes) in impoundments, the solids concentration had increased, making plumes persistent for long distances. There were complaints. But there was no litigation against the companies during that time. In 1930, flotation technology allowed the recovery of the phosphate from deeper zones. This was because the "concentrate" size phosphate rock was in the sand-size range and could not be screened out. Centralized beneficiation plants grew into a three-step process - washing and screening, feed preparation and flotation (Fig. 2). Reagent storage, safety and the flotation cell complex made the plants into large capital installations. Larger draglines were required to dig deeper into the matrix. These had dramatically larger production capacities, which were then figured into the overall material balance for a given plant. The number of operators shrank and the production per operator grew. Larger areas were being bermed off for waste clay storage. An economic incentive became apparent for storing as much waste clay as possible in each settling area. At the same time, the population was steadily growing and more eyes were watching the activities of the phosphate mines. Phosphate mining, focused on production and profit, was earning a bad name from its neighbors. When the subject of phosphate mining

Jan 1, 1998

By Peter K. Weissenborn, Robert J. Pugh

The contrasting behaviour of electrolytes in inhibiting coalescence of bubbles was explained by the positive and negative distribution of anions and cations at the gadwater interface. Further, the efficiency of electrolytes which do inhibit coalescence of gas bubbles can be linked to a counter ion hydration mechanism and the effect of electrolyte concentration on gas solubility. A correlation was found between the transition concentration of electrolyte needed to prevent the coalescence of bubbles and the reduction in gas solubility. Hence, the inhibition of bubble coalescence in electrolyte solutions appears to be linked with the utilization of water molecules in the hydration of cations and a consequent reduction of water available for gas solubility.

Jan 1, 1995

By W. P. Blacutt

A financial-economic model incorporating physical, market and policy variables has been developed for mining investment in Bolivia. Additional risk criteria emanating from political instability, new mining legislation, recent environmental regulations and a new minerals taxation system are accounted for and are integrated into the investment decision model. Results of the model indicate that geologic and market variables have the dominant effect on the investment-worth function. Among policy variables, exchange rate and taxation policies have the most significant influence. Depreciation allowance for infrastructure development has negligible weight in the investment-worth function. The business structure of the firm considering investing in the Bolivian Polymetallic Project, is found to be an instrumental factor in the investment-worth outcome.

Jan 1, 1995

By J. E. Gebhardt, S. Chander

Significant advances have occurred in the use of electrochemical techniques for sulfide mineral flotation research. The techniques have been used singly or jointly with other characterization methods. When used in combination with other methods, the electrochemical methods provide a means to control the state of oxidation of the surface. Various analytical methods are employed for characterization. The methods that have been used include wetting, x-ray photoelectron and fourier transform infrared spectroscopies. The electrochemical methods include voltammetry and transient electrochemical techniques of galvanostatic polarization and AC impedance spectroscopy. The challenge for the future lies in the utilization of this knowledge in plant operations so as to increase the overall efficiency of flotation separations.

Jan 1, 1989

By Donald A. Dahlstrom

If you have ever driven on the Autobahns of Western Germany, you are well acquainted with the "fast lane." There is no speed limit; there are only two lanes in the direction you are going, and if you choose to drive in the fast lane, you had better be prepared to drive faster than anyone or someone will tailgate you with a constant screeching horn until you move to the "slow lane." The prize for this mastery of the fast lane is some kind of a "macho" feeling and getting to your destination sooner than your competitor. This has some comparisons with today Is liquid-sol id separation. We've certainly had our moments in the fast lane but we've also had other countries forcing us into the slow lane at times. It can be very embarassing when someone almost runs over your back and then shakes a fist at you as you shakily scatter to the much slower and overcrowded lane. Because of necessity, there will be many new improvements and added requirements in the next decades into the 21st century and beyond. Those countries and industries that can maintain the pace in the fast lane will be successful while the others may well be relegated to the non-competitive lane. Before considering what will be the challenges in the future for competitive liquid-sol id separation performance, it would be wise to review progress over the past forty years in this area. The author has to admit his ancient age and believes he can act as an evaluator of these many advances. To place the beginning of the 40 years (the author predates his initiation into liquid-sol id separation by one more year), the United States was still building smelters and operating them with little or no sulphur dioxide removal , practically

Jan 1, 1989

By Q. Lin, D. Z. Wang

Molecular design plays an important role in development of new flotation reagents. Group electronegativity calculation is a main method of molecular design. It is commonly used in calculating the hydrophilic-hydrophobic balance of reagents, particularly in designing chain length of flotation reagents for located minerals. But there is a limit to group electronegativity method. The method can only apply to those of [Ø]known straight-chain compounds ([Ø] is the hydrophobic energy of each -CH2- , determined by experiment). In this Paper, we propose another new calculation method: fragment method of flotation reagent. The method could be used as a supplement of group electronegativity method to design and calculate flotation reagents without any limitation. With the fragment method, we can calculate the hydrophilic-hydrophobic performance of any known or unknown reagents including those complicate structure compounds such as cyclic, branch, heterocyclic and so on by summing the appropriate structural elements (fragment). The principle, calculation stages and some results of designing new-type flotation reagents by fragment method are presented in this paper.

Jan 1, 1995

By Donald E. Ranta

Many portions of the mining industry are under intense pressure to reduce costs while commodity prices languish. In response, global Internet-based marketplaces to deliver business-to-business (B2B) e-commerce solutions are being established to reduce costs and improve efficiencies across the mining industry supply chain as well as with customers. Over time these marketplaces will likely evolve to create an integrated supply chain solution, layer in value-added services, and develop mining community portals with industry content. Significant opportunities to help reduce costs and create value are available in mining e-procurement as well as in on-line product sales. The supply chain for the industry is highly fragmented and many mining companies have numerous inefficiencies in procurement. An e-procurement marketplace (or "exchange") can immediately address these inefficiencies and offer numerous benefits to buyers and suppliers. These benefits include improved sourcing options, inventory cost reduction, transaction cost reduction, access to value-added services, lower customer and supplier acquisition costs, improved reach, and improved information flows.

Jan 1, 2001