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The Subtropolis mine is a room-and-pillar mine extracting the Vanport Limestone near Petersburg, Ohio. In February 2018, mine management began implementing a heading reorientation to better control the negative effects of excessive levels of horizontal stress. The conditions in the headings improved, but as expected, stressrelated damage concentrated within crosscuts. The mine operator has worked to lessen the impact of the instabilities in the outby crosscuts by implementing several engineering controls. With the implementation of each control, conditions were monitored and analyzed using observational and measurement techniques including three-dimensional (3-D) LiDAR surveys.

Jan 7, 2020

By D. Janicijevic

This paper describes the process of scraper winch pull force measurement and shows the results of the actual winch pull force in extreme stall situations as well as during the face and gulley cleaning. It was found that by slowing down the motor and causing it to slip, torque up to 3.5 times higher than the nominal can be developed, resulting in the same increase of winch pull force. On the other hand, measurements of the actual force needed for cleaning of the face and the gully have shown that the currently used winches are too powerful. The extra torque that can be developed by the already too powerful winch motor poses a significant danger and necessitates the implementation of measures that will eliminate this risk.

Jan 1, 2008

By Douglas D. Donald

The New Jersey Zinc Co. successfully holed through a 2 1/2-mile haulage tunnel connecting its new Ivanhoe shaft with the Van Mater Shaft at Austinville, Va. This 8x 10-ft cross-section tunnel was driven from both ends and met at a point approximately a mile from one shaft and a mile and a half from the other. In order to make certain that the faces met accurately on line and grade it was necessary to refine conventional mine surveying practices. The mines that are serviced by these shafts are located in the southwestern part of Virginia approximately midway between Roanoke and Bristol at the west foot of the Blue Ridge. While the presence of lead-zinc sulfide ores has been known in this area for more than 200 years, it was in 1902 that New Jersey Zinc Co. acquired the Austinville property, which has been in constant operation since that time. About ten years ago the company undertook an extensive diamond drilling program at Ivanhoe several miles to the southwest. This program was successful in locating sufficient ore to justify the purchase of a number of the properties in this area and plans were made to develop the new orebodies. The discovery of this ore as well as substantial addi- tional reserves at Austinville resulted in a decision by the company to increase its daily milling capacity to 3000 tons, of which about 1000 tons would be supplied from the Ivanhoe mine. After careful consideration of all possible methods of transporting this volume of ore from Ivanhoe to the mill, it became evident that diesel locomotive haulage through a 2½-mile tunnel between the two mines would best suit prevailing conditions. Since the lowest operating level, known as the 1100 level, of each mine would be at approximately the same elevation, it was obvious that such a tunnel should be driven on this level. Not only would this tunnel facilitate feeding Ivanhoe ore into the underground crusher and skip loading installation at Austinville, but it would also open up a known orebody 5000 ft southwest of the Van Mater shaft. In addition it would provide a valuable diamond drilling base from which a large and a potentially favorable but untested block of ground might be explored. In order to hasten the completion of the tunnel, it was felt that it should be driven from both ends. ENGINEERING CONTROL PROCEDURES It was vital that the tunnel junction be made accurately on line and grade; thus it was felt that engineering control of an unusually high degree of reliability was required to prevent an accumulation

Jan 1, 1959

By James Ridenour

This report represents the first comprehensive accounting of lode mining sites in the Loon Creek mining district, Custer County, Idaho. Thirty-five mine and prospect locations have been added to the Bureau's Mineral Industry Location Subsystem (MILS) data base as a result of initial phases of a mineral appraisal of the River of No Return Wilderness; previously known locations were field checked and the updated information added to the data base. The district's major deposits are gold-copper-silver fissure-fillings hosted by biotite schist intruded by dikes ranging in composition from rhyolite to lamprophyre. These deposits contain a trace element suite similar to Tertiary pink granites and may be related to intrusion of the nearby Casto pluton. Continued firm gold prices could stimulate the search for precious metal occurrences in this and other mining districts in central Idaho.

Jan 1, 1983

By M. J. McLeod, D. R. Lux, R. P. Taylor

"The Mount Douglas Granite constitutes the eastern part of the Saint George Batholith and contains the youngest, most differentiated phases of the batholith. It also contains extensive endogranitic, low-grade. Sn- W-Mo-bearing sheeted vein systems. Early phases of the Mount Douglas Granite are coarse- to medium-grained, seriate granites that represent the slowly cooled carapace of the intrusion. Late phases are medium- to fine-grained, equigranular and porphyritic granites that were accompanied by repeated and widespread fracturing of the carapace and injection of mineralizing fluids. These granites represent a highly differentiated suite with ""A "" type affinities developed in a ""within plate"" transitional to ""syn-collision"" tectonic setting. 4oAr/ 39Ar dates for biotites from the various phases indicate emplacement circa 367 Ma.The linear distribution of some phases in the Mount Douglas Granite and the systematic orientations of sheeted veins along tensional fractures indicate structural control on granite emplacement and vein distribution. This type of relatively passive endogranitic mineralization is unique in the granites of southern New Brunswick and contrasts markedly with highly fluidized systems operative elsewhere in the area. IntroductionInvestigation of Sn-W-Mo occurrences in New Brunswick has shown that most of this mineralization is associated with late, highly differentiated phases of post-orogenic (Acadian) granitoid magmatism that occurred during Devonian and Early Carboniferous time (Ruitenberg and Fyffe, 1982; Taylor et al., 1988). The polymetallic Mount Pleasant Sn-W-Mo deposit (Ruitenberg, 1967, 1972; Kooiman et al., 1986)and the Burnt Hill W deposit are two orebodies of this type in New Brunswick. Numerous smaller deposits associated with these granitoid rocks in southwestern New Brunswick have been documented in previous investigations (Ruitenberg, 1967, 1968; Ruitenberg and Fyffe, 1982; Taylor et al., 1985; Lentz, 1985)."

Jan 1, 1988

Bortech’s BoreClad corrosion protection system will be displayed at MINExpo. BoreClad is an innovative system for inside diameter cladding of nozzles, tubes and other circumferential devices. Pressure vessels, mud pumps and other mining equipment must be protected from corrosive caustic chemicals. Usually manufactured from mild steel, they can be clad with a protective material, such as stainless steel, to provide corrosion resistance. However, most welding processes leave voids where corrosion can damage the base metal. BoreClad provides void-free welds by combining gas metal arc welding with automated feed and rotation of chuckable parts. Workpieces of up to 915-mm- (36-in.-) long with a 460-mm- (18-in.-)swing can be clad with stainless steel, Iconel or other exotic metals. In addition to eliminating the voids associated with hand welds, BoreCladcan lay more than 2.2 kg/h (5 lbs/hour) of metal. That is a significant reduction in weld time. Web sitewww.bortech.com.

Jan 1, 2004

By E. O. Afreh, R. J. Bowell, E. Hanssen, D. Pohl, S. Abe, R. K. Yao, N. d'A. Laffoley

In the largely preserved laterite profiles at Syama mine, in the savanna region of southern Mali, element geochemistry in the mottled-clay horizon and below can be related directly back to the protolith, but above this, in the ferricrete and cuirasse horizons, the hypogene signature is much modified by pedogenic processes. In tropical rainforest terrains extensive remobilisation can result in wide but weak geochemical targets for gold and pathfinder elements. At the Hire concession in central Ivory Coast, intense recent alteration of the largely intact laterite sequences has modified soil-geochemical dispersion patterns extensively, producing Fe-rich nodular stone lines and obliterating previous patterns and features. Where the upper horizons of the laterite profile have been removed or reworked, as at the Senoufo concession in northern Ivory Coast (savanna) or the Kubi prospect in Ghana (rainforest), all soil horizons can be related directly to hypogene geochemistry. In these truncated profiles, gold and base metal anomalies are essentially those of the lower weathering profile and form narrow but strong dispersion haloes. A good understanding of the geochemical processes active in deeply weathered profiles is required if targets are to be recognised effectively

Apr 1, 1996

Reduce the number of accidents in which large mining trucks crush objects that were not visible to the driver. Approach Improved rear view mirrors, light-bending plastic lenses, and a closed circuit TV, are combined in a rugged system that allows the driver to see almost all areas around a large raining truck. How It Works Improved mirrors, used in place of ordinary left and right rear view mirrors, give wider angle viewing. Fresnel lenses, two mounted on the front edge of the hood and another one mounted above the right front fender, show objects close to the front and right side of the truck. A rugged closed circuit TV camera mounted above the rear axle reveals objects behind the truck. See diagrams showing reduction of blind area around a 150-ton mining truck. The improved mirrors for rear viewing are approximately rectangular. The left rear view mirror has a flat reflecting surface 10 inches wide by 20 inches high. The right rear view mirror is curved to give wider viewing angles, both from left to right and up and down. This mirror is 12 inches wide by 16 inches high. Its convex reflecting surface has the same curve as the surface

Jan 1, 1979

By J. A. Finch, Zhenghe Xu

The competitive adsorption of xanthates on sulphide minerals in a binary mineral system (pentlandite and pyrrhotite) was studied using the pseudo-in-situ technique of attenuated total-reflectance FTIR spectroscopy. The minerals were placed in the same collector solutions, either separated by a glass wall or in direct contact with each other before magnetic separation and separate analysis. The effect of mineral interaction on xanthate adsorption was clearly demonstrated spectroscopically for the first time. At low concentrations of xanthate, its adsorption on pentlandite was activated by physical contact with pyrrhotite; the effect may be attributed to the enhancement of electron transfer through electrical contact between the two minerals. The results emphasise the need for caution in extrapolating results obtained from single-mineral studies to flotation practice

Jun 18, 1905

By M. B. McClenaghan

"This paper summarizes diamond exploration techniques used in glaciated terrain, focussing on indicator mineral and geochemical methods applied to glacial sediments. Understanding the ice flow history, depositional history, and stratigraphy of glacial sediments is essential to successful sampling, interpretation and follow-up of indicator mineral and geochemical anomalies related to kimberlites. Kimberlite indicator minerals survive glacial transport over long distances and the relative abundance of each mineral in till is a function of the primary mineralogy of individual kimberlites. Indicator mineral distributions observed at a regional scale define the net effect of glacial dispersal, often along different ice flow directions. Local-scale distributions define individual dispersal trains. The medium sand (0.25 mm to 0.5 mm) fraction of heavy mineral concentrates, * GSC Contribution No. 2002028 prepared from glacial sediment samples, is best suited for indicator mineral surveys. The application of till geochemistry to diamond exploration is increasing because it is significantly cheaper than indicator mineral analysis and it can be performed quickly. The <0.063 mm (silt+clay) and 0.5 mm to 2.0 mm (coarse sand) fractions provide the best geochemical contrast between background and kimberlite-rich till. Kimberlite pathfinder elements that provide good contrast include Ni, Cr, Ba, Co, Sr, Rb, Nb, Mg, Ta, Ca, Fe, K, Ti and LREE, the relative importance of which will depend on kimberlite composition and that of the surrounding bedrock.IntroductionIn Canada, glacial erosion is the principal means by which kimberlite and its associated minerals have been dispersed, from a few tens of metres to tens of kilometres down-ice. Post-glacial weathering has had little impact on kimberlite debris in the glacial sediments, thus boulder tracing, indicator mineral methods and trace element geochemistry of the fine fraction of till (“drift prospecting” methods) can be used to detect kimberlite dispersal within areas covered by glacial sediment. This paper provides a summary of drift prospecting methods for kimberlite exploration in glaciated terrain, and includes examples of reconnaissance- , regional- and local-scale kimberlite indicator mineral and till geochemical distribution patterns.Weathered kimberlite is more susceptible to glacial erosion than the surrounding bedrock, thus many kimberlites in glaciated terrain are found in low or swampy ground, under small lakes, or covered by thin (< 1 m) to thick (>50 m) glacial sediments. Glacial erosion has removed varying amounts of the pre-glacially weathered kimberlite and, in some cases, the hard competent kimberlite below. For example, glacial erosion of the Peddie, McLean and Seed kimberlites near Lake Timiskaming, Ontario, removed pre-glacially weathered kimberlite, leaving a polished striated subcropping surface (McClenaghan et al., 1999a). In contrast, glacial erosion of the B30 kimberlite, near Kirkland Lake, Ontario (Fig.1), was much less vigorous and left a >10 m cap of soft and highly weathered dark green clay-rich kimberlite (McClenaghan et al., 1996). The thickness of remaining pre-glacially weathered kimberlite will influence the geophysical signature of the kimberlite."

Jan 1, 2002

By Jacques J. Eksteen

Any effort to improve the metallurgical control of industrial furnaces employed in the primary extraction of high carbon ferroalloys are bound to fail unless the variability of the melt is not fully accounted for. A number of sampling campaigns were performed on both 3phase AC submerged arc and single phase DC open arc furnaces at different smelter sites in South Africa where High Carbon Ferrochrome is produced. It was found that the heterogeneity between multiple samples during a single taps were much higher that for heterogeneity found within a sample. Moreover, this heterogeneity (as quantified by the relative standard deviation per tap) varied with the operating conditions of the furnace, the element monitored and the type of furnace. A relationship was found between the relative standard deviation of certain elements and the degree of subcooling of the melt.

Jan 1, 2006

Recovery of Rhenium from Mineral Raw Materials of Kazakhstan

Sep 13, 2010

By Roy A. Grancher

HAPPY BIRTHDAY Not only is 1971 the Centennial Year of the AIME, but it also marks the One Hundredth Anniversary of the United States Portland Cement Industry. On September 26th in 1871 David O. Saylor of Allentown, Pennsylvania, received his patent Numbered 119,413 for the manufacture of portland cement. "Cement" had been used in the United States before that. This was, however, natural cement - a direct product of rocks as found in nature, usually burned at low temperatures in open kilns. During the early 1800s this natural cement played an important role in such projects as the building of the Erie Canal. It was only after the Civil War that small amounts of high priced portland cement was imported from Europe. The successful use of this material in construction led to Saylor&apos;s experiments and subsequent patent for the manufacture of a scientifically controlled product in this country. These one hundred years have witnessed four major "ages" of cement . . . three of them occurring in the last quarter century since World War Two. The first age was the "Age of Development", a seventy-year period which saw the growth of cement and its concrete end uses as major construction materials. Next followed a period called the "Age of Demand" when, after the war, cement became in short supply relative to large building requirements. In effect a cement shortage existed. The decade of the Sixties proved to be the "Age of Reaction", with its courses of action coming in response to the problems that arose when the industry&apos;s expansion programs provided too much capacity. Today cement, and the concrete industries, find themselves entering the "Age of Reason". Overcapacity, low price, rising costs, and poor returns are several of the reasons behind that name, As these industries face the construction challenge of the Seventies, and beyond, the application of basic management principles (otherwise known

Jan 1, 1971

ALTHOUGH it has been a matter of about one hundred years since the idea of the internal-combustion engine entered the mind of the inventor, the practical application of its use was not attained till 1860, when Lenoir produced an engine similar to the ordinary highpressure steam engine, with the valves arranged to admit the explosive mixture and the discharge of the exhaust gases. In this case no attempt was made to compress the gas before ignition, as it was then considered that the explosion under these conditions had a detrimental effect, inasmuch as it would act as a sudden blow to the working parts. Indeed, he went so far as to inject steam and water sprays to reduce the explosion.Under these conditions the consumption of gas was exceedingly high-about 106 cub. ft. of coal gas per b.h.p. per hour but the mechanical effect showed that the engine ran in every respect as smoothly and quietly as in best steam-engine practice.The extravagant consumption of this engine was clearly pointed out at the time by Gustav Schmidt in a paper before the German Society of Engineers, wherein he states :-&quot; The results would be far more favourable if compression pumps, worked from the engine, compressed the cold air and cold gas to three atmospheres before entrance into the cylinder. By this means a greater expansion and transformation of heat is possible.&quot;

Jan 1, 1912

By Richard S. Watt

The Bureau of Mines is often called upon to analyze the demand for various minerals and fuels and to make projections of the future demand. Because minerals and fuels are raw materials and because the demand for raw materials [pends] on the demand for finished goods, these projections are usually [conned] with derived demand rather than final demand. In order to obtain quick [d] reasonably accurate analyses of the demand for mineral commodities, the [reau] developed a method and has used it successfully (31).4 To illustrate the [thod], this report presents a full analysis of the demand for a mineral commodity with enough general theory to permit application of the method to any mineral. Sodium chloride (common table salt) was chosen as the subject of the analysis because the demand for it is less complicated5 and permits a simple application and clear presentation of the method.

Jan 1, 1962

People in economically developed societies demonstrate inherent human care for Earth and want to stop pollution. Yet efforts to clean Earth seem bogged in confusion from wildly contradictory and alarmist predictions of æclimate crisisÆ. Supposed experts openly disagree yet weÆre told thereÆs universal agreement humans are causing æthe end of life as we know itÆ. The turmoil combines with peopleÆs feelings of fear, guilt, anger, hopelessness and even resignation and apathy to trigger æclimate alarmÆ. The paper enables people to rediscover clarity, hope and support for Earth by understanding how climate alarm and confusion were created and how they actually increase pollution. Many people seem to think global warming is as serious as pollution and worry that questioning alarm will enable pollution. Yet theyÆre different. We need be even more concerned about climate alarm because history shows repeatedly that when buried by ignorance and panic real problems grow overwhelming. Environmental credibility is endangered by confused politicians and sensationalist media. When weÆre willing to re-evaluate what weÆve been told we replace fear and confusion with facts and freedom to identify opportunities. Combining this with practical understanding of human behaviour and leadership enables opportunities to be identified and action taken. The paper shows how confident, informed leadership leads and supports higher productivity and effective care for the natural environment.

Jan 1, 2009

By Douglas B. Silver

Traditional cycle theory would postulate that if you have a supply shortage relative to demand, the price will increase because buyers will incrementally increase the price they are willing to pay to ensure that their needs are fulfilled. As prices rise, more supply will be brought on and will eventually exceed demand. This supply excess will cause the price to decline as producers have to lower their prices to sell their goods. What is interesting is that cycles are simply volatility over time. Without the time factor, volatility simply goes up and down. When we add the time element, a cycle is created. This cycle can be big or small. In mining?s case, we are talking about a Super Cycle ? a big cycle. But a Su-per Cycle can be formed in two ways. It can form by either increasing the wavelength or the volatility. If these two elements are combined, a Super Cycle is formed. It is bigger than the normal cycle in terms of time duration and extent of volatility. A recent study (Fig. 1) conducted by Cuddington and Jarrett showed an interesting proof of Super Cycles and suggests that these cycles last between 15 and 30 years. So, what causes a Su-per Cycle? Is it a convergence of unrelated events or a consequence of related events? In a global community everything is related. Equilibrium theory would also take the position that a Super Cycle is a consequence of events.

Jan 1, 2008

Flotation of Phosphate Gangue from Magnetite Fines - Non-Ionic Surfactant as Atrac Collector Modifier

Sep 13, 2010

Iron ore in the Middleback Range area has a density and susceptibility contrast with adjacent rocks, and gravity and magnetic methods are applicable to exploration for it. The gravity method is satisfactory whether the ore mineral is hematite, magnetite, or limonite; the magnetic method is suitable for detecting ores which contain magnetite, such as some hematite ore, magnetite ore, and possible ore in the form of magnetite-bearing schists. jaspilites, and carbonate rocks.Geophysical exploration began in 1948 and is still in progress. The methods which have been used are aeromagnetic (83 per cent), ground magnetic (13 per cent), gravity (3 per cent), and others (1 per cent). Ground magnetic surveys have been made wherever aeromagnetic surveys recorded large anomalies. The gravity method is being used to investigate those parts of the area considered most favourable for ore occurrence.Qualitative and quantitative interpretation of the geophysical data has been made and the rocks causing selected anomalies tested by bores.Magnetite in the Middleback Group rocks produces the major magnetic anomalies in the area. The average magnetite content of magnetite-jaspilite, which is the commonest rock type, is 33 per cent by weight and that of magnetite-carbonate at the Iron Duke-Iron Duchess is 50 per cent. These rock types also contain hematite and the average total iron content of the former is 35 per cent and of the latter 50 per cent.INTRODUCTIONThe geology and iron ore resources of the Middleback Range area were described by Miles (1954). Since 1954, much drilling, mapping, and quarrying has been done but there is no published report of this work.The rocks which constitute the Middleback Range, Camel Hill-Cooyerdoo line, Katunga Hill-Iron Knob, and Ash Range (Fig. 1) belong to the Middleback Group of Middle Precambrian or late Archaean age. Most outcrops of the Group are jaspilites, formerly called banded hematite (or magnetite) quartzite. The high grade hematite deposits...

Jan 1, 1964

THE present article makes no claim to be exhaustive, since it cannot contain all the knowledge which scientists and manufacturers of the compounds of the rare earths have gained. The following notes are, therefore, simply an attempt to ascertain andclearly record the occurrence, properties, and uses of the more important of the rare earths, with a special reference to their commercial values and the industries based upon them.HISTORYIt was the mine manager, Gcyer, of Stockholm, who, in 1788, first drew attention to a black mineral which had been found in a quarry near Roslagen, in Sweden. In 1805 Klapproth received some specimens of this mineral, which he declared to be a newmineral. Subsequently Gadolin, professor of chemistry at Abo, analyzed the same mineral, and determined the presence of an unknown earth resembling alumina and lime. He named the mineral ytterbite, and afterwards gadolinite. Klapproth has alsothe merit of having detected (1804) another rare earth, which he named ochroit-earth, found in the Bastnas mine, near Riddarhyttan, in Wcstmannland, Sweden. Curiously enough, Hisinger and Berzelius simultaneously ascertained the existence of the same...

Jan 1, 1909