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By G B. Arehart, S J. Mathews, J L. Mauk

The banded nature of the quartz veins which form the Empire lode at the Golden Cross mine, is perhaps their most striking feature. Petrographic studies show that significant differences occur between the bands in terms of textures, quartz grain size, calcite, adularia and kaolinite content, and the form, concentration and mineralogy of sulfide phases.   The d18Oquartz values of individual bands within the vein material range from 7.3-10.9ë. Calculations show that the d18Oquartz values can be adequately explained by temporal variations in the system temperature, boiling and/or variations in the systems fluid/rock ratios.

Jan 1, 1995

By Timothy Batchler, Khaled Mohamed, Morgan Sears

The National Institute for Occupational Safety and Health (NIOSH) initiated a testing program to assess the effects of lateral loading on various standing supports used in underground coal mines. This study is not intended to endorse a particular type of standing supports nor to provide a comparison between different types of standing supports. This paper aims to measure the lateral loading capacity of two types of standing supports and evaluate how it affects their vertical loading capacity and yielding mechanisms. The study utilizes the Mine Roof Simulator (MRS) at NIOSH Pittsburgh. Type-1 support is characterized by telescopic tubes made from ASTM A-513 steel with a specified locking mechanism, and Type-2 support comprises a single component constructed from ASTM A500 Welded Grade C pipe. Vertical load tests were carried out to assess the designed performance of Type-1 and Type-2 props. Type-1 props demonstrated a "constant yielding" behavior, achieving an ultimate capacity of up to 140 kips. Type-2 props showed a "load shedding" behavior, reaching peak verti- cal loads of up to 191 kips. Buckling analysis revealed that Type-1 props were not designed to buckle, and Type-2 props failed due to buck- ling rather than material yielding. Under vertical pre-loading, lateral loading tests showed that Type-1 props can withstand about 9 kips, and Type-2 props can withstand about 10.79 kips of lateral load. This represents roughly 6% of their vertical loading capacities. Testing props under lateral loads in addition to their intended vertical loads showed that the lateral loads could influence their loading mechanisms. Type-1 props did not exhibit the expected "constant yielding" behavior under lateral load but instead showed "load shedding" decreasing their rated vertical capacity by 70%. At high vertical pre-loading, Type-2 props demonstrated "constant yielding" behavior instead of the anticipated "load shedding," leading to a 60% reduction in their rated vertical capacity. These findings provide valuable insights into the behavior of these props under different loading conditions, aiding in their efficient use and design in underground mining operations.

Jun 25, 2024

By F. P. Agterberg, A. G. Fabbri

"A statistical analysis was done on the locations of 718 copper and 1 257 gold deposits in Abitibi. This area of about 20 000 square miles is one of the better-explored metal-producing areas of Canada.Patterns of clusters were studied by harmonic analysis. Several two-dimensional power spectra showed a number of distinct peaks. Sets of crest lines for patterns of interfering waves were constructed on the basis of these peaks. They pass through elongated clusters of deposits which are spaced more or less equally. For copper these periodic regularities in location may coincide with geological structures largely of Archean age (major fractures and sedimentary belts indicating synclinal structures). A directional relationship with swarms of diabase dykes of known ages and distinct attitudes indicates that the gold mineralization is, in part, younger than the copper mineralization."

Jan 1, 2014

By Lin Daoyi

In this paper, we have adopted the high pressure jet-grouting curtains to seal the sea-water, and to consolidate the wall of the well for deep foundation diteh, make a pladge of building and construction of deep foundation was primarily on progress without water. This paper, we have been given a test for pumping water under mainly the circumtances of sealing condition and to report in advance the capacity of seawater seeping into the gam curtains in the process of building and construction of deep foundation.

Jan 1, 1991

By Walter Keune

Object Modeling Technique. This formal descriptive language makes it possible to formulate requirements in the real world in such a way that they can be implemented in the form of entities (cf. Entity Relationship Model[Che83]) and methods (see Figure 1). The object {Roadway} is graphically depicted by means of the Polygon method.

Jan 1, 1996

By A. Bouajila

To stay competitive in an open market, mineral industries have to optimise their processes, lower their production costs and improve the commercial value of their products. Up to a recent past, they were impaired in this attempt by a lack of adequate devices allowing reliable on-line and real-time process monitoring (detection or measurement). Process monitoring for process control and the product characterisation for quality control are quite different tasks. Planners and researchers should be fully aware of this when evaluating or developing monitoring equipment for on-line process control. This paper will comment on some aspects of sensor specifications, during the design and the evaluation steps, related to sampling, measurement (accuracy, sensitivity, delay and correlation to the process) and suitability to the exploitation environment. Examples of R&D projects promoted by COREM for various industrial applications will be presented.

May 1, 2001

By Jr. Matthews

The Candelaria copper-gold deposit is located in Region m of Chile, 805 kilometers north of the capital, Santiago. Candelaria was discovered in 1987, following a six month exploration program. In late 1986, induced polarization (IP) surveys outlined an anomalously high response within the area of interest. The first test hole bad three intersections totaling 49 meters, with an average grade of 1.97% copper. Drilling eventually outlined approximately 390 million tonnes, grading 1.09010 copper and 0.26 grams/tonne gold. Production began in early 1995 and is estimated at 120,000 tonnes copper and 80,000 ounces gold annually.

Jan 1, 1996

By Ginger S. Evans

This report documents a preliminary hydrologic investigation of an area where longwall mining methods are to be used. The scope of work includes: determination of physical and chemical characteristics of major soil types in the area; determination of physical and chemical properties of surface water bodies; collection of geologic characteristics, including stratigraphy, structure, and detailed aquifer descriptions; collection of 10 years' meteorological data and installation of a weather station; and a detailed ground-water investigation that includes completion of observation wells, aquifer testing, water quality sampling, and analysis using a 3-D computer model. The Trescott model developed by USGS was used to simulate steady-state aquifer conditions. Input data from 8 multiple-completion monitor wells were used to model an area of approximately 10 square miles. Two layers, coal and overburden, were simulated, both confined. Model results showed good agreement with know piezometric data, desaturated areas, and flow from springs. The study area was found to have very low-yield bedrock aquifers with transmissivities ranging from 5 to 320 ft2/day for the coal (depths from 500 to 1,200 ft) and from 499 to 576 ft2/day and fractured sandstone units (depths less than 100 ft). Annual precipitation and recharge are very low, 10 to 11 inches and 0.25 inch respectively. The area has very high relief and large areas of rock outcrop. No perennial streams are present on the site.

Jan 1, 1983

By Bloom M. S

Epithermal vein and breccia hosted Au mineralisation at the Kerimenge prospect, in the Wau district, Papua New Guinea, occurs within a block of multiply fractured dacite porphyry of Pliocene age, and is localised on intersecting regional fault structures, marginal to the eroded vent of a Late Pliocene-Pleistocene maar volcano (diatreme).Au mineralisation is primarily controlled by the steeply dipping Kerimenge Fault zone, which hosts a basal zone of silicified breccias,transitional laterally and vertically to networks of fracture controlled veins.Early quartz+pyrite veins, deposited from CO2 rich, NaCl saturated, boiling fluids pre-date the main phase of Au mineralisation. Four stages of Au bearing vein mineralisation have beenrecognised. Quartz+sulphide veins (stage 1) and partially coeval quartz+sulphide+carbonate+ adularia veins (stage 2) occur marginal to silicified breccias, and are associated with quartz+sericite+pyrite wallrock alteration. Similar depositional conditions prevailed for stage 1 and stage 2 mineralisation. Mineralising fluids underwent two stage boiling at temperatures of 145 to 2300 C. Boiling resulted in the loss of approximately 3 wt.% CO to the vapour phase. 2 Fluid salinity was probably I wt.% NaCl or less.

Jan 1, 1990

By Marthie Kotze, Jacolien Wyethe, Bert Van Hege, Richard Bell

Base metal refinery effluent streams may contain low metal concentrations that cannot be recovered by precipitation. Although the concentration is low, the total mass of unrecovered metal can have significant value because of the volumes of effluent generated. This metal may be recovered with high efficiency using selective ion exchange resins. Three process schemes are considered, viz., fixed bed column ion exchange, continuous countercurrent resin-in pulp, and continuous carousel resin-in-pulp. Each of these has different requirements in terms of equipment, resin inventory, capital and operating costs, and different limitations on feed conditions. Bateman and Mintek recently developed a model which allows an upfront economical evaluation of ion exchange options. The model evaluates the capital and operating costs for each process scheme for various base metals. This provides a general guideline for selecting the appropriate process arrangement for a given process stream.

Jan 1, 2005

By F. Cihangir, A. Kesimal, K. Karaman, B. Ercikdi

Uniaxial compressive strength (UCS) and shear strength parameters(cohesion and angle of internal friction, Cand F) of rocks are important parameters needed for various engineering projects such as tunnelling and slope stability. However, direct determination of these parameters is difficult and requires high-quality core samples for tests. Therefore, this study aimed to explore the applicability of the Brazilian test (BT) - a simple, less sophisticated and inexpensive method for both specimen preparation and testing - to estimate the UCS and shear strength parameters of rocks. Thirty-seven rock types were sampled and tested, 24of which were volcanic, 8 were metamorphic, and 5 were sedimentary. Statistical equations were derived to estimate the UCS and shear strength parameters of rocks using the BT. The validity of the statistically derived equations was confirmed using predictive analytics software (PASW Statistics 18). A strong linear relation was found between BT and UCS values. BT and UCS values exhibited prominent linear correlations withthe cohesion values of rocks. The Mohr envelope was also used to determine the cohesion and friction angle of rocks using BT and UCS values. It is deduced from the current study that the BT values can be used to estimate the UCS and cohesion. However, no relation was observed between the angle of internal friction values and the UCS and BT for all rock types. Therefore, different approaches are suggested for the estimation of the internal angle of friction for application in the preliminary design of projects.

Jan 1, 2015

By R. G. B. Pickering

Over the last few years Lonmin Platinum and Sandvik have embarked on a unique partnership of collaboration through a systematic approach to developing equipment to mechanize and automate narrow reef platinum mining. After the initial design and manufacture of the equipment the key aspect is the integrating equipment, people and method into a mining system. Another key aspect of mechanization is the optimization of equipment utilization, and this philosophy has ensured continual evolvement of mining methods. This paper describes the trials and development that have resulted in the mining method described as Lonmin mechanized breast.

Jan 1, 2007

By C E. J de Ronde, J L. Mauk

Sulfide chimney samples collected during the 1998 - 1999 R/V Atlantis û DSV Alvin 3 - 30 research cruise have been examined and classified into four types, based on common characteristics. Chimney morphology is the most important characteristic and resulted in the following groups: 1. flutes, 2. cones, 3. wide-flats, and 4. beehives. Other characteristics resulted in the classification of subgroups within the flute, cone and wide-flat groups. The combination of characteristics, including; the presence of an orifice, internal chimney fabrics, wall thickness, extent of weathering, and the presence of Alvinella worm casts, enable evolutionary trends between the different chimneys types to be established. These trends indicate that with time, flutes evolve from immature zoned chimneys with a central orifice and smooth thin-walls, into cone chimneys with thick walls and massive fabrics which have their orifices infilled by massive sulfides, and a rough exterior. Repeated mineralisation within, cones may result in the formation of wide-flat chimneys. Beehive chimneys can form at any time during chimney growth.

Jan 1, 2003

By P. J. O'Connor, V. Gallagher

examined analytically in relation to the ratio of the

Dec 1, 1994

CONTENTS PAGE ZAPFFE, CARL.-Manganiferous Iron Ores of the Cuyuna District, Minnesota. Discussed by A. K. Knickerbocker 1 MCCORMACK, C. P.-Economics of the Cuyuna Manganiferous Iron Ores. Dis-cussed by T. L. Joseph, J. Wilbur Van Evera, C. P. Perin, T. T. Read, L. E. Ives 4 READ, T. T.-Probable Error in Blast-furnace Records and Calculations Therefrom. Discussed by C. H. Herty, Jr., T. T. Read, T. L. Joseph, Ralph H. Sweetser 8 SCHWARTZ, H. A. and HIRD, (Mrs.) ANNA NICHOLSON.-Chemical Equilibria During Solidification and Cooling of White Cast Iron. Discussed by N. B. Pilling, Ralph H. Sweetser, H. M. Boylston, Albert Sauveur 10 HERTY, C. H., JR., BELYEA, A. R., BURKHART, E. H., and MILLER, C. C.-Some Factors Affecting the Elimination of Sulfur in the Basic Open-hearth Process. Discussed by Henry D. Hibbard, L. F. Reinartz,. C. H. Herty, Jr., Ancel St. John, A. L. Feild, C. R. Hayward, Ralph H. Sweetser, C. D. King, Haakon Styri, George A. Orrok 12 HIBBARD, HENRY D.-Finishing Melting Temperatures of Simple Ingot Steels. Discussed by Haakon Styri, George V. Luerssen, A. G. Zimermann, A. L. Feild, George A. Orrok, Albert Sauveur, R. F. Harrington, Henry D. Hibbard, I. A. Billiar, William J. Priestley, H. W. Gillett, W. P. Barba, Jerome Strauss, Harry H. Smith, H. LeChatelier, L. F. Reinartz 19 HERTY, C. H., JR., and TRUE, O. S.-The Reaction between Manganese and Iron Sulfide. Discussed by A. L. Field, H. S. Rawdon, C. H. Herty, Jr., T. L. Joseph, Haakon Styri 37 KAMURA, HEIHACHi.-Reduction of Iron Ores by Carbon Monoxide. Discussed by T. L. Joseph, R. Franchot, Ralph H. Sweetser, C. H. Herty, Jr 43 JOSEPH, T. L.-Effect of Sulfur on Blast-furnace Process. Discussed by R. Franchot, C. A. Meissner, T. L. Joseph, C. H. Herty, Jr., Ralph H. Sweetser, I. E. Waechter, F. N. Speller, T. T. Read 45 GOOSTRAY, JOB, HARRINGTON, R. F., and HOSMER, M. A.-Brief History of Metallurgical Practice in Cannon-making with Particular Reference to the Cast-iron Gun. Discussed by A. G. Zimermann, Geo. A. Orrok, Chas. Me-Knight, Jr., F. Brauer 51 Manganiferous Iron Ores of the Cuyuna District, Minnesota Discussion of the paper of CARL ZAPFFE, presented at the New York Meeting, February, 1925, and issued, as Paper No. 1390-I, with MINING AND METALLURGY, December, 1924. A. K. KNICKERBOCKER,* Virginia, Minn. (written discussion).¬The author makes a broad distinction between the "black" ores (the

Jan 6, 1925

By Kang-In Rhee

Nonferrous metal recycling not only provides energy saving and environmental benefits but also is a significant factor in the supply of various types of metals used in our society. Recycling plays an important role in establishing the sustainability of materials. The total amount of recycled nonferrous metals by weight accounts for less than 5% but their value is larger than 50% compared to ferrous metal recycling which consists of about half of the total metal recycling in weight. This paper describes trends and typical achievements in nonferrous metal recycling and overviews the present and future of nonferrous metal recycling technology and business in Korea.

Jan 1, 2006

By Kang-In Rhee

Nonferrous metal recycling not only provides energy saving and environmental benefits but also is a significant factor in the supply of various types of metals used in our society. Recycling plays an important role in establishing the sustainability of materials. The total amount of recycled nonferrous metals by weight accounts for less than 5% but their value is larger than 50% compared to ferrous metal recycling which consists of about half of the total metal recycling in weight. This paper describes trends and typical achievements in nonferrous metal recycling and overviews the present and future of nonferrous metal recycling technology and business in Korea.

Jan 1, 2006

By Kang-In Rhee

Nonferrous metal recycling not only provides energy saving and environmental benefits but also is a significant factor in the supply of various types of metals used in our society. Recycling plays an important role in establishing the sustainability of materials. The total amount of recycled nonferrous metals by weight accounts for less than 5% but their value is larger than 50% compared to ferrous metal recycling which consists of about half of the total metal recycling in weight. This paper describes trends and typical achievements in nonferrous metal recycling and overviews the present and future of nonferrous metal recycling technology and business in Korea.

Jan 1, 2006

By Kang-In Rhee

Nonferrous metal recycling not only provides energy saving and environmental benefits but also is a significant factor in the supply of various types of metals used in our society. Recycling plays an important role in establishing the sustainability of materials. The total amount of recycled nonferrous metals by weight accounts for less than 5% but their value is larger than 50% compared to ferrous metal recycling which consists of about half of the total metal recycling in weight. This paper describes trends and typical achievements in nonferrous metal recycling and overviews the present and future of nonferrous metal recycling technology and business in Korea.

Jan 1, 2006

By Kang-In Rhee

Nonferrous metal recycling not only provides energy saving and environmental benefits but also is a significant factor in the supply of various types of metals used in our society. Recycling plays an important role in establishing the sustainability of materials. The total amount of recycled nonferrous metals by weight accounts for less than 5% but their value is larger than 50% compared to ferrous metal recycling which consists of about half of the total metal recycling in weight. This paper describes trends and typical achievements in nonferrous metal recycling and overviews the present and future of nonferrous metal recycling technology and business in Korea.

Jan 1, 2006