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By David K. Hylbert

This study investigated stratigraphic and structural causes of roof falls in room-and-pillar drift coal mines in nine mines in eastern Kentucky. A contract modification provided for remote sensing studies in the Dunkard Basin of West Virginia and Pennsylvania. Results of stratigraphic and structural studies of an earlier contract (H0133018) were applied to several new mines. It was found that similar rock sequences contributed to unstable roof conditions. Structure contour and isopach maps were found useful In projecting these trends together with fence diagrams. Using Landsat imagery, a direct relationship was found between lineament direction and the trends of rock jointing, roof fall zones, "snap top" zones and sandstone channels in the examples cited. It was found that, by analyzing lineament intersections, from 50 percent to 65 percent coincided with roof falls.

Jan 1, 1980

By S. Vivek

An atomic force microscope (AFM) was used to measure the surface forces between silica surfaces immersed in solutions of hydrolysable cations and/or sodium oleate. Hydrophobic forces were observed at the pH range where the concentration of the singly-charged hydroxo-complexes (CaOH+ or MgOH+) in solution is the highest. In the absence of oleate, the adsorption of the hydroxo-complexes was indicated by the disappearance of the repulsive hydration force. These results suggest that the hydrolysable cations adsorb on silica as singly-charged hydroxo-complexes. Based on the results obtained in the present work, a model for the adsorption of hydrolysable cations has been developed.

Jan 1, 2009

By A. R. Biggart

Twenty-sixth Sir Julius Wernher memorial lecture, presented at the Tunnelling '94 symposium held in London, 5-7 July 1994. In describing 18 projects with which he has been involved over a period of 36 years, the author aims to illustrate how technological change and an increase in scientific knowledge have influenced tunnelling practice, which he nevertheless maintains does continue to be an art. Tunnels discussed are: the Silver Street, Blackfriars, Whitechapel, St. Paul's and Waterloo Post Office tunnels, 1958-1969; metro tunnels on the Victoria Line, London, 1962-1970; the introduction of tunnel boring machines (TBMs), 1971-1978, in the Empingham reservoir diversion tunnels in Rutland, the bentonite tunnelling machine experiment at New Cross, the Southern tunnel water main section of the London Ring Main and the Warrington sewer in Cheshire; tunnels in rock 1975-1981, for the Lune Wyre and Megget Manor aquaducts, Weymouth sea outfall and Bristol interceptor sewer; Priestley TBM tunnels 1969-1982; the Greater Cairo wastewater project 1983-1987; Anacostia River crossing, Washington DC 1985-1987; the Channel Tunnel 1987-1992; and the Storebaelt eastern tunnel in Denmark, 1992-1994.

Dec 1, 1994

By Stefan Basista, Janusz Tomala

Modern constructions of electric ferroalloy furnaces are still based on applying in the lower "liquid" areas the standard carbon materials. What can be illustrated by the experience from several years, in the part of tap hole, hearth walls and bottom, is that so-called carbon or semigraphite microporous materials are successfully being applied. These materials, compared to the standard carbon, give better resistance to the attack by liquid metal and other wear factors. Generally this group includes materials characterised by considerable share of pores of diameters below1µm (significantly exceeding 90% of total porosity). The microporosity increases the resistance to the infiltration of the liquid metal. The effect of microporosity can be obtained by introducing silicon (or its compound) additive to materials based on electrically (or gas) calcined anthracites, electrographite and binder. Moreover, by introducing other ceramic additives, the microporous materials are more resistant to dissolution by the liquid metal. Observing the trends of "improving the materials" in the last years, it is clearly seen that the share of non-carbon additives is bigger and bigger, so we can reasonably speak of rather carbon-ceramic materials. In this paper, the survey of the most important quality criteria, which must be met by the carbon furnace linings, as well as the new testing methods will be presented.

Jan 1, 2007

By C E. J de Ronde, J G. Scott

Economic gold mineralisation was discovered at Round Hill by Homestake NZ Limited in 1984 and was subsequently put into production by Macraes Mining Company Limited (MMCL) in 1990. The total mineral resource in 1990 was estimated at 41.4 Mt @ 1.42 glt at a 0.7g/t cut off, for 1.8 Moz of gold. Since project start up the mill has been upgraded twice to increase throughput and reached its current capacity of 3.2 Mtpa. At 31 December 1996, a total of 16.2 Mt of ore at average grade of 1.73 g/t has been excavated, yielding 655,000 oz of gold. MMCL began exploration along the Hyde Macraes Shear Zone in 1994. Since 1994, exploration has been successful with the discovery of over 3.5 Moz of gold. The resource now stands at 110 Mt @ 1.46 g/t gold for 5.1 Moz. This success has led to a planned expansion of the processing capacity to 9 Mtpa with the building of a new 6 Mtpa processing plant.

Jan 1, 1997

These proceedings consist of papers presented at a Bureau of Mines Technology Transfer Seminar in September 1981 for the purpose of disseminating recent advances in mining technology in the area of premining research. The introduction and descriptive papers discuss techniques and instrumentation used in premining research for metal and nonmetal mining and shaft design and borehole control for premine planning.

Jan 1, 1982

By D. Potter

In 1990, Freeport Exploration began regional reconnaissance exploration programs in Irian Jaya, the easternmost province of the republic of Indonesia (Fig. 1). Irian Jaya occupies the western half of the island of New Guinea. Freeport was awarded an initial contract of work that totaled 2.6 million hm2 (6.4 million acres). The company was subsequently awarded additional concessions that added 1 million hm2 (2.5 million acres). The concessions require work commitments and periodic relinquishments. Due to these relinquishments, Freeport’s current land position totals 1.9 million hm2 (4.7 million acres). Freeport began the exploration program to locate additional Grasberg deposits, the largest deposit in the Ertsberg district. But the company recognized that other types of deposits could be present in the largely unexplored area of Irian Jaya.

Jan 1, 1999

By T. C. Alex, S Srikanth, Premchand

It has been suggested that reduction of the iron and manganese phases as far as FeO and MnO is preferred for the complete liberation and selective reduction of the copper, nickel and cobalt oxides in manganese nodules. The oxygen partial pressure/temperature regime suitable for this purpose has been delineated. Free-energy minimisation and thermogravimetric results indicate that the requisite conditions can be achieved if more than 10% of neutral oil is used at temperatures greater than 923 degrees C. Neutral oil content, temperature and roasting time have been optimised to maximise leaching recoveries of Cu, Ni and Co: up to 96% of Cu and Ni and up to 85% of Co can be recovered if 15% of neutral oil is used as a reductant at 973 K for 90 min

Jun 21, 1905

Study on Treatment of Wastewater Containing Heavy Metal Ions Using Modified Oceanic Cobalt-Rich Crusts

Sep 13, 2010

By M. Fan

Froth flotation is the most widely-used method of separating fine coal, especially coal with coking properties. However, froth flotation is not efficient for treating ultrafine coal and coarse coal particles. Our previous fundamental test results demonstrated that cavitation-generated nanobubbles can significantly improve coal and phosphate flotation performance over a wide particle size range. In this study, the effect of nanobubble on the flotation performances of different particle size fractions of coal was investigated using a bank of 10-liter flotation cells, a specially designed 50 mm inside diameter column and a 152 mm inside diameter column. It was found that nanobubbles that were either directly formed on or subsequently attached to the surface of coal particles during coal froth flotation process improved flotation efficiency. The use of nanobubble in a bank of mechanical cells flotation and column flotation significantly increased the flotation recovery at a given product grade. Nanobubbles increased the flotation rate constants of different coal particle sizes. The presence of nanobubbles in flotation slurry could extend the lower and the upper particle size limits for effective coal flotation.

Jan 1, 2012

By Charles "Chick" Rodgers

"The Key Lake uranium mine is the largest single uranium producer in the world. It is owned 2/3 by Cameco Corporation and 1/3 by Uranerz Exploration and Mining. Cameco is the operator. Current production is fourteen million pounds per year of uranium oxide (U308).The mine's location is 570 kilometres north of Saskatoon on the southern edge of the Athabasca Basin approximately at latitude 57° 11 'north and longitude 105° 34' west. Access to the mine is by an all-weather road and a private airstrip.The mill was commissioned in 1983. A molybdenum plant was constructed in 1989 in response to increasing molybdenum content in the yellowcake or final product. Early test work had showed that the first ore body to be mined, the Gaertner deposit, would present few problems with regards to molybdenum in the product. However, the test work also showed that the higher molybdenum content of the Deilmann ore, the second Key Lake orebody to be mined, would result in increased molybdenum concentrations. Without the molybdenum plant, penalties would become excessive and some product might not accepted by the refineries.This paper will describe the current Key Lake mill process with emphasis on the molybdenum solvent extraction process. It will cover the chemistry of the process, process development in the mid 1980's, and current operating practices.The Key Lake milling process consists of five individual plants, crushing and grinding, leaching -counter current decantation (CCD), solvent extraction, yellowcake/crystallization and bulk neutralization (Figure 1. Simplified Mill Flowsheet). A detailed mill flowsheet can be found in the appendix."

Jan 1, 1996

By Paula Maria Gomes Cunha Leão, Flávio de Castro Dutra, Fabrício Vilela Parreira, Silvio Maranha

In the iron ore beneficiation, tailings are inherent in the concentration processes to which the ores are subjected for the production of commercial products. The large generation of tailings has been motivating the study of technological alternatives for its reuse, with the development of processes that contemplate the concentration of fine ore particles present in the tailings, such as the reintroduction of these particles in the process of manufacture of the iron and steel itself, through the agglomeration techniques such as briquetting. The aim of this article is to study the technical feasibility of the production of iron ore tailings and coking coal briquettes for use in reduction reactors, through a systematic review of the literature on agglomeration, briquetting and self-reduction processes, covering the main variables that influence the production of high quality briquettes, such as binders use, binder behavior of coking coal, coal granulometry, iron ore and coal proportion, compacting pressure and temperature of thermal treatment and the effects of these variables on briquettes final properties.

Oct 1, 2019

By C Cavern, G Jacobs, F Durufle, L Ameglio

Airborne geophysics and geomatics is at a crossroads as to whether it remains a viable mapping tool, both technically and commercially, and broadens its potential for new applications (eg environmental monitoring, civil engineering and precision farming). The use of small and stable multisensor aerial platforms to conduct highly flexible surveys flown at a low/reasonable cost of operation is a recurrent wish of many stakeholders in the natural resources exploration and mining industry. Through its Fly Light Airborne Geophysics research program, EXIGE and partners have pushed the development and testing of two new airborne carriers with unique capabilities for geo-surveys: GyroLAG’s gyrocopter and Infotron’s unmanned aerial vehicle (UAV). These carriers are the next generation of versatile and innovative aerial vehicles for remote sensing and monitoring. They are rotary, smart tailored, ultra-high resolution manned (gyrocopter) or autonomous (UAV) airborne platforms that combine the merits of dense data sampling, accurate position location, very low clearance above ground or sea level, slow speed, interchangeable and combined multiple geo-sensors, automatic data quality control and real-time quality assurance. They also have the benefits of being highly efficient, cost-effective, commercially attractive, safe, reliable and easy to deploy and operate. Their technical specifications and multiple advantages compared to traditional aircraft and/or ground crews are presented in this paper. An overview of various geo-sensors (magnetic, gamma-spectrometry, visual, near-infrared and LiDAR) carried on-board is also provided.CITATION:Ameglio, L, Durufle, F, Jacobs, G and Cavern, C, 2015. Light airborne platforms for monitoring mines and minerals, in Proceedings Third International Future Mining Conference, pp 11–20 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

The Fraser Range is composed dominantly of basic pyroxene granulites derived from basalts, many of which appear to have been vesicular and pillowed. Acidic and basic garnet-bearing granulites are important in the west, and acidic granulites and narrow anorthosite layers are dominant in some regions east of the Fraser Range. An extensive flat-lying olivine gabbro sheet cuts the granulites, and in places has been converted to spineI-bearingmeta-gabbros and pyroxene granulites. The granulites of the Fraser Range (Proterozoic) are separated from the gneisses and schists of the goldfields regions (Archaean) by the Fraser Fault, over which there is a large gravity anomaly (gradient 20 milligals per mile). Some of the problems associated with the concentration of Cu, and Ni liberated from mineral lattices during metamorphism, and other principles of metal concentration in granulite terranes, are discussed. The recognition of vesicular and pillowed zones, even though highly metamorphosed, is of fundamental importance.

Jan 1, 1969

By J. L. Gillson

Joseph H. Birman (Chairman, Dept. of Geolcgy, Occidental College, Los Angeles, Calif.) Many thanks to J. L. Gillson for so comprehensive a survey of the titanium sand deposits of the world. Over the past two years, the writer studied rather carefully some of the Cretaceous ilmenite deposits in New Mexico and Colorado, including the Sanostee deposit shown in Gillson' s map, Fig. 6. The deposits were geologically mapped and sampled, surveyed by magnetometer, and the Sanostee deposit was drilled. Moat of the genetic interpretations made by Gillson concerning the recent sedimentary ilmenites can be clearly read in the Cre-taceous deposits in New Mexico. The deposits are in marine regressive members of the Mesaverde group. The deposits trend within a few degrees of N 55° W and persistence of this trend through both distance and time (the deposits are in different members of the Mesaverde group) implies that the deposits are offshore bar accumulations. Heavy mineral content ranges from about 10 pct to more than 50 pet. Thicknesses are from 4 ft to as much as 20 ft, widths range from 150 to 600 ft, and lengths range from a few thousand feet to a few miles. All are locally or completely overlain by carbonaceous shale and thin coal. The deposits are strongly altered, and from X-ray diffraction the principal titanium alteration product appears to be anatase. Drilling of the Sanostee deposit shows that the alteration is not related to the present erosion surface but took place at the site of deposition and before burial by the overlying sediments. Iron oxide derived from the alteration cements the grains and is the chief coloring agent in the immediately overlying shales. In the Sanostee deposit, there is virtually no feldspar, the gangue mineral being almost exclusively quartz. Sorting is excellent, but the quartz grains are subangular to angular. Petrographic examination reveals that the angularity is not due to overgrowths. Therefore, short distance transport is implied. The mineralogical composition suggests a low relief granitic terrane as the source area. Feldspar may have been decomposed by weathering at the source, but an alternative preferred by the writer is that each of the deposits represents a long-term concentration site (for example a large sand bar) which was continually being deprived of light minerals by wave action and selective transport. Feldspar may have been mechanically reduced in size more quickly than the quartz, and thus its rate of removal may have exceeded that of quartz. Concentration of heavy minerals would thus occur until the marine regression removed the zone of maximum wave energy from the site. Chemical alteration would then become the most important process until burial by encroaching swamp deposits.

Jan 1, 1961

By Alcides Eloy Cano

Los recursos minerales de un depósito está en función de las dimensiones de la geometría del cuerpo mineral, así como sus reservas minables permiten saber el verdadero valor económico de su contenido. En este sentido, la Geotecnia es una herramienta que define las condiciones de los esfuerzos in situ, predice el comportamiento alrededor de excavaciones subterráneas e interactúa con las labores próximas, así como también la distribución de esfuerzos. Por ello, el presente trabajo señala la aplicación de esta herramienta a una mina subterránea de Oro localizada en el Perú, donde se tiene bloques de mineral económicos, así como señala su accesibilidad con leyes encima del Cut-Off. De forma que se recupera el mineral económico a través de las rutas críticas de carguío, en función de la viabilidad de autosostenimiento.

Sep 12, 2011

By Randy R. Huberty

Although originally designed with deep foundations consisting of all driven steel H piles and drilled caissons, a unique application of Augered Cast-in-Place (ACIP) piles as an alternate design resulted in a significant cost savings for the Midfield Terminal Project at the Pittsburgh International Airport. The project was enormous in scope covering an area two miles long by one mile wide, with changes in elevation of over 200 ft. The varying geology combined with the large amounts of fill required resulted in a complex set of geotechnical design parameters that had to be evaluated through both load testing and analyses. A total of almost 400,000 lineal feet of ACIP piles were installed for this project.

Jan 1, 2001

By Christopher Haycocks, Lawrence P. Johnson, George M. Neall, James M. Townsend

No method of roof control yet devised has proven to be universally acceptable for the wide range of strata conditions experienced in U. S. coal mines. However, a relatively new innovation, the roof truss, has proven itself capable of preventing roof failures which both conventional and resin bolting could not. Presently, the economics of roof trusses are not favorable when compared to bolting due primarily to drilling and installation procedures, but this is expected to change with improved truss and equipment designs. To realize the full potential of this new method of roof control, design criteria are needed which can optimize the effect of the truss for varying strata conditions. A review of the literature reveals that some work has been conducted on the roof truss. Cambrell and Haynes1 (1970) showed that the roof truss is superior to angled roofbolts installed through a header. Sheorey, Verma, and Singh2 (1973) used statics to prove that the optimum angle of inclination should be greater than 45°. However, to date, no systematic attempt has been made to establish design criteria. In this paper, the problem was approached in three ways. First, model studies were performed to determine general trends of truss support as a function of a number of variables. This provided a better understanding of the support mechanism involved. Secondly, beam theory was employed to calculate the actual support capacity of a truss, realizing the many simplifications, assumptions, and shortcomings of this approach to such a complicated problem. Last, field testing will be utilized to test the hypotheses previously developed and provide hard data to further synthesize roof truss design criteria. Field testing has recently commenced and should be complete before mid 1977.

Jan 1, 1979

By Stanley Lefond

The health of the industrial minerals industry appears to be improving year by year. In fact, preliminary information suggests that only three commodities (asbestos, bromine, and sulfur-other) failed to show a production gain in 1984 over 1983. In 1983, 10 commodities failed to post gains and six remained constant. The total value of industrial mineral production in 1984 was $16.7 billion, up $1.4 billion from 1983. Cement, clays, gypsum, and crushed stone production increased. Since these are used in housing and construction, this suggests these industries are moving out of their recent doldrums. Barite and clay production also improved in 1984. Local US barite production, however, still has a long way to go to attain the 1981 high of 2.6 Mt (2.9 million st). Barite imports remain high. But they are not as high as the 1982 importation of 2 Mt (2.3 million st). Bentonite production in 1984 increased 20% in volume and 25% in value over the previous year. This suggests improvement in the drilling industry and an increase in demand for iron ore pelletizing grades. All in all, the industrial mineral industry is alive and well. And it shows signs of great improvement in the next few years. Many thanks to those industrial mineral technical committee members for their assistance in assembling this industrial minerals review: M. F. Dibble, H. W. Allen, G. H. Gallup, S. G. Ampian, D. W. L. Spry, H. G. Fleshman, and L. J. Czel.

Jan 5, 1985

The Use of Automated Mineralogy to Interpret the Batch Flotation Performance of Merensky Reef Ore

Sep 13, 2010