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By C E. J de Ronde

Most of the world's economically significant volcanogenic massive sulphide (VSM) deposits are considered to have formed in submarine arc and backarc settings. While the Kermadec-Tonga arc is an excellent example of an intra-oceanic arc setting, it remains largely unexplored in terms of submarine mineral resources. More than half of this arc (~1400 km of the >2500-km-long feature) lies within the EEZ of New Zealand, where it is defined by at least one sub-aerial and 33 submarine volcanoes. The NZAPLUME (New Zealand American PLUme Mapping Expedition) cruise of March 1999 provided a systematic assessment ofhydrothermal activity on the southernmost 13 submarine volcanoes along the southern Kermadec arc. Using prospecting techniques based on the physical and chemical detection of hydrothermal plumes, we discovered that more than half (7 of 13) of the southern Kermadec volcanoes host one or more active hydrothermal systems at depths ranging between <200 to 1800 m. Chemical results show that the fluids discharged are compositionally diverse among volcanoes and between sites at a single volcano. Plumes over more than half of the volcanoes are gas-rich (He, CO2, H2S) relative to mid-ocean-ridge (MOR) plumes. In addition, most sites are highly enriched in Fe, yielding Fe/Mn values that far exceed those for MORs. One interpretation consistent with these observations is compositional overprinting by addition of magmatic fluids, which are typically highly enriched in gaseous and ionic components. Regardless of the source, it is clear that the ligands (HS-, Cl-) required to efficiently transport base (e.g. Cu, Zn, Pb) and precious (e.g. Au, Ag) metals to the seafloor are abundant in Kermadec arc fluids. We conclude that modem analogs of VMS deposits are likely forming at multiple sites along the Kermadec arc and within the EEZ of New Zealand.

Jan 1, 2000

By Amado Yataco Medina

Año a año el incremento de muertes por ignición del gas metano o carbón en concentraciones mayores a las soportable, se hace cada vez mayor. Por tal motivo, el presente texto refiere la importancia de las normas de control y seguridad, como las factores sobre la explosividad del polvo del carbon. Entre estos tenemos: la distribución de partículas, composición de polvo, el gas inflamable en el aire, cantidad de polvo, distribución de polvo en la mina, fuentes de ignición, rugosidades de la labor y cambio de sección. Existen dos formas de prevenir dichas explosiones: la primera, es a través de la prevención de acumulación de gas por medio de la ventilación y la segunda, es por medio de la eliminación de las posibles causas de la ignición. Asimismo, se sugiere una serie de recomendaciones de prevención de explosión, como se describe los reglamentos del Código de Minería.

Aug 20, 1965

By J. M. Houston

"In October 1982, Rio Algom Limited, purchased a tin prospect near East Kemptville, Nova Scotia, from Shell Canada Resources. This purchase led to the development of the first substantial tin mine in North America. This paper deals with the drillingand blasting operations at Rio Algom, in particular the use of emulsion explosives technology.This presentation describes what emulsion explosives and Heavy AN/FO are, and the support system used to deliver these products to the blast site.HistoryThe East Kemptville mine site was discovered by Shell Canada Resources (SCR) in July 1978. SCR started diamond drilling on the tin prospect in March 1979. After 8220 m of BQ drilling, it was estimated a reserve of 56 000 000 tonnes of 0.165% Sn was present.The property, which is located 54 km northeast of Yarmouth, Nova Scotia (Fig. 1), showed, after a feasibility study that, given an ore treatment rate of 9000 tonnes per day, a mine life of 17 years could be expected.GeologyThe tin deposit of the East Kemptville Mine, occurs in granitic rocks at their contact with metasedimentary rocks. The mineralization is in the form of cassiterite with associated sulphides of copper and zinc. The tin occurs in a stockwork of tin bearing Greisen alteration zones.East Kemptville MineThe mine planned an open pit operation with the first five years being mined at a rate of 14 000 tonnes per day, of which 5000 tonnes will be waste and low grade ore. Eventually, the total mining rate will be 21 000 tonnes per day, including 12 000 tonnes of waste and low grade ore. Figure 2 shows the general layout of the mine site.East Kemptville Chooses Emulsion ExplosivesIn December 1984, East Kemptville Mine awarded the Explosives Division of C-I-L Inc. a contract to supply explosives to the borehole. The system chosen gives East Kemptville the on-the-bench choice of regular AN/Fa, or a high density, Heavy AN /Fa product called SuperAN· or a water resistant emulsion explosive called MAGNAFRAC· for holes that cannot be dewatered.Emulsion ExplosivesAn emulsion is an intimate mixture of two liquids that do not dissolve in each other. Emulsions have contributed to our daily lives in such products as insecticides, salad dressings and cosmetics."

Jan 1, 1987

By Alejandro Freyre B.

"El presente texto señala el proceso de explotación de la veta Shiusha situada en el distrito de las minas de Huarón. La veta es de origen hidrotermal, cuyo rumbo aproximado es E-W, y su buzamiento varía de 75º N en el Estea 85º N al Oeste, uniformizándose en los niveles inferiores en 85º :N. El eje mayor probable del depósito ( plano Nº. 1 '), tiene una inclinación de 25 º E. El depósito se extiende sobre una longitud de 1100 m, entrelas coordenadas 4600 - 57 00 E., pero la calidad y cantidad del mineral son variables en las tres dimensiones. Asimismo, se describe la prospección, preparación para corte y relleno, arranque, intermedias de los tres compartimientos y la aplicación de gradines descendentes vacíos."

Aug 20, 1963

By Basilio Ponce Pío

La industria minera busca reducir los costos de operación y optimizar la producción a través de una modernización de las operaciones minero metalúrgicas. Bajo esta premisa, la mina Uchuccahua utiliza un nuevo método de explotación denominado "explotación por subniveles con taladros largos". En este sentido, el presente texto señala la aplicación del método a través del block mineralizado de plata llamado "Claudia", cuya explotación alcanza también a las vetas que sean mayores de dos metros. Así también revisa la recuperación de un block mineralizado en la veta Irma Viviana, la cual estuvo abandonada por derrumbes al inicio de la explotación.

Apr 1, 1991

By Marcelo Gagó M.

El presente trabajo describe las secuencias y parámetros del método de corte y relleno descendente en la explotación económica del cuerpo mineralizado de la bolsonada Fastidiosa y muestra la factibilidad de su aplicación en minas donde las características son semejantes. En este sentido, el método aumenta el rendimiento mediante la utilización de un scoop y elimina el sostenimiento tradicional a través de la utilización del relave aumentado, ofreciendo confianza y seguridad al personal en operación.

Oct 14, 1980

By V. Astucuri

El presente trabajo describe el proceso de extracción de plata de dos muestras de relaves antiguos empleando la cianuración. De acuerdo a este estudio, entre todos los procesos metalúrgicos utilizados para la recuperación de la plata como la tostación sulfatante, amalgamación, flotación, se encontró que la cianuración es un proceso completo ya que puede reemplazar a las anteriores, con excepción de la amalgamación de plata nativa y otras deficiencias. En consecuencia, la cianuración es el método hidrometalúrgico que aprovecha mejor el poder lixiviante de los cianuros alcalinos en soluciones diluídas y extrae la palta de los relaves. Por ello, se supedita a su contenido económico y a los minerales no económicos entre los que se encuentre asociado.

Oct 14, 1980

By T. Tamagawa, N. S. Fu, I. Iwasaki, M. Kobayashi

A 3-stage fluidizing bed process of chlorination, selective oxidation and sulfur chloride conversion was tested for processing of a chalcopyrite concentrate. It was found that the use of excess oxygen was essential to a stable operation in the oxidation reactor. The oxygen-excess gas will inevitably cause the oxidation of the sulfide concentrate in the chlorination and sulfur chloride conversion reactors. A new flowsheet is proposed to separate the chlorination and the selective oxidation steps with separate flow paths of the fluidizing gases, thereby preventing the passage of oxygen-excess gas in the chlorination and sulfur chloride conversion reactors. The feasibility of the proposed flowsheet was demonstrated in a laboratory-scale fluidizing bed setup.

Jan 1, 2000

By Frank E. Woolley, Robert D. Pehlke

Jan 1, 1965

By J. F. Colinet, W. R. Reed, J. D. Potts

Dust surveys were conducted at six underground coal mines to determine if deep-cutting practices expose face workers to higher levels of respirable dust. The surveyed mines were able to successfully mine deep cuts without significantly increasing the dust exposures of face workers. In general, all of the selected mines exercised good dust control practices by maintaining water sprays, scrubber airflows, proper curtain setback distances and providing sufficient airflow to the active faces. For exhausting face ventilation, field data indicate that scrubber airflow is the most important factor for controlling dust. Data collected for this study indicate that 20-mesh screens should be cleaned for every 12.2 m (40 ft) of advance, because 22% of the deep cuts surveyed for this study experienced a 20% to 35% decrease in scrubber airflow over the course of the cut. For blowing face ventilation, field data and past research indicate that dust control is aided by maintaining a proper curtain-to-scrubber airflow ratio of 1.0 (measured before scrubber activation), as well as a curtain setback distance that allows the miner operator to stand at the mouth of the curtain for the entire cut. Dust levels on the bolting faces did not appear to be affected by the longer cycles associated with deep-cut mining when good ventilation practices were used.

Jan 1, 2011

By NEWTON B. KNOX

PERU, lying south of Ecuador and having common frontiers with Brazil, Chile, and Bolivia, includes over a thousand miles of the Andean mountains. The coastal plain is arid and narrow and the Amazonian jungle region is of interest only on account of its oil and gold placer possibilities. The mountain zone, however, here forms one of the world's most highly mineralized regions. The Peruvian Andes, like their Bolivian and Ecuadorian counterparts, form two distinct chains separated by the great Apurimac and Maralion valleys; but these rivers cut through the Eastern range to join the Amazon drainage, and the central valley is missing north of the passes thus formed by these rivers; the localities where the ranges are joined are aptly called knots. In addition, in central Peru, there exists a third range lying to the east of the first two and separated from them by the Urubamba and Huallaga Rivers. The Eastern range, however, is of little importance to the miner for few metal deposits are to be found therein except for the gold mineralization in the South. In general, deposition of metals in the Peruvian Andes accompanied igneous intrusions which invaded the folded Paleozoic and Mesozoic rocks during the Tertiary; thus the ore bodies are all typical of shallow or moderate depths.

Jan 1, 1945

By A. Iannacchione

Most legacy drift mines entered the coal reserve from outcrop and developed up-dip. The Surface Mining Control and Reclamation Act of 1977 changed this way of mining, requiring all new mines with acid- or iron-producing coal seams to be designed so as to prevent gravity water discharges from the mine. This Act requires engineered barriers to contain the mine pool. In many cases, mine layout designs focus primarily on the size and hydraulic performance of the un-mined coal barrier between the up-dip mine pool and areas where down-dip surface discharge is possible. In other cases, designs focus on preventing discharges from barriers contained within the strata surrounding the mined coalbed. This paper focuses on a detailed analysis of the factors responsible for preventing mine pool discharges to surface waters. Important factors include: mine layouts, mining methods, hydraulic head and conductivity, and geology. While the exact causes for the successes and failures could not always be determined, reasonable mechanisms are presented.

Feb 23, 2014

By D. Harrington

ANNUAL or necessary inspections and investigations of coal mines for various purposes were made possible through the Federal Coal Mine Inspection Act of May 7, 1941, which authorized entry to the Secretary of the Interior through the Bureau of Mines. Primary object of these inspections is to obtain information pertaining to health and safety conditions. Among the purposes for which the data are to be used, are annual reports to Congress, the publication of inspection reports, and the compilation and publication of statistics. The act states that inspections and investigations shall be made by employees of the Bureau of Mines, who shall co-operate with other bureaus of the U. S. Department of the Interior, as well as with the official mine-inspection, safety cr health agencies of the several states and territories. The act specifies that a coal-mine inspector shall have "the basic qualifica-

Jan 1, 1946

By D. Blackwell, W. R. Reed, G. Ross, S. Peters, M. Shahan

Dust collectors for roof bolting machines generally use a dry box to collect the roof bolting material. Recently, an underground mining operation converted a dry box dust collector to a wet box dust collector with a unique exception from MSHA for testing purposes.Water is routed to the roof bolter fromthe main water line of the continuous miner. The wet box utilizes a water spray to wet the incoming material. Testing was conducted comparing the two different collector types. Respirable dust concentrations surrounding the roof bolter with the different collection boxes were similar. The main difference in respirable dust concentrations occurred when cleaning the dust boxes. The average respirable dust concentration during cleaning of the wet box was 0.475 mg/ m3, and during the cleaning of the dry box, the average respirable dust concentration was 1.188 mg/m3, a 60% reduction in respirable dust concentration. The quartz content of the roofmaterialwas high, ranging from 28.9 to 52.7%during this study. The results from this study indicate that using the wet box as a collector reduced exposure to respirable dust up to 60% when cleaning the collector boxes.

Aug 26, 2020

By N Power, A D. Costar

There has been significant growth in mining and energy exploration in South Australia, which has identified new major potential opportunities. This sector generates significant economic value to the state and their support remains a priority for the state government. The delivery of this economic and associated community value to the state is dependent on the mining and energy sector being able to access reliable water supplies.The vast majority of priority areas for the mining and energy sectors are located in areas that have traditionally been of low priority from a water-use perspective and hence, data and knowledge levels are generally low.Recent studies have identified a potential increase in demand for water in the mining and energy sector for potential developments from approximately 40 GL to over 170 GL over the next ten years. The studies found that water and water infrastructure is the second highest proportion of planned infrastructure capital investment by resource companies. The South Australian GovernmentÆs Plan for Accelerating Exploration (PACE) initiative (PACE 2020), also identifies addressing the issues of location, use and management of South AustraliaÆs water resources as a key priority for the growth of the mining and energy sector.The Department of Environment, Water and Natural Resources (DEWNR) has developed the facilitating long-term outback water solution (FLOWS) initiative. DEWNR is currently undertaking a suite of programs to provide groundwater information at the regional scale to better target water supply options for mining and energy developments and community water supplies.The Goyder Institute for Water Research has leveraged significant research investment of $3 M to develop methodologies to interpret airborne geophysics to map groundwater sources.The FLOWS Initiative will provide key content for the PACE Water Program and will also assist in the development of water supplies for remote far north communities by identifying alternate groundwater sources to improve water supply security.This paper will discuss how developing an appropriate science and knowledge base will encourage and secure development where appropriate, enable prudent decision-making and policies regarding water allocation, accounting and licensing, whilst ensuring the protection of environmental assets.CITATION:Power, N and Costar, A D, 2013. Finding long-term outback water solutions, in Proceedings Water in Mining 2013 , pp 191-196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By Donald R. Rathburn

Screening during the production of high-grade lump ore for blast furnace burden, particularly from recently developed ore deposits in Australia, South America, and Africa, has resulted in large tonnages of fine iron ore. Certain owners have decided to stockpile these fines until some later date; however, others have either sold these fines "as is" for agglomeration at the steel plant or have established their own pelletizing plants to produce a premium quality agglomerate. Normally these fines consist of the higher oxides of iron and the hydrated oxides. Unfortunately, grinding these types of materials in a wet process produces a slurry that is difficult to filter to obtain the requisite moisture level for the subsequent balling and indurating operations. The purpose of this paper is to review recent developments in fine dry grinding of iron ore and to discuss the various design and operating parameters involved. Although dry grinding of raw feed and clinker has been practiced in the cement industry for many decades, its significant application to the iron ore industry has taken place within the past ten years. Even though the basic concept of dry grinding has been borrowed from the cement industry, the successful application to iron ore grinding has not taken place without some difficulties. Consequently, the application to iron ore has required the solution of several unique design and operating problems.

Jan 1, 1970

The paper describes a practical methodology based on numerical modelling for the prediction of progressive failure of underground mine stopes with cable bolt support. A case study of the 40-761 stope at Kidd Creek Mine, Timmins, Ontario is presented. The stope was mined by blasthole open stoping in 1986 as a lead stope within a mining block between 36-1 and 38-2 levels. Initially designed to peak at 38-2 level, the stope back caved upwards approximately 40m towards 36-1 level. Cable bolts were installed above the stope from 36-1 level after caving had begun. The stope eventually stopped to cave when the falling rock mass encountered a sufficiently high cable density. The paper provides details of the geomechanical data and modelling results of the case study. Numerical modelling is carried out using a finite element package known as e-z tools which has, among other things, a special cable/rockbolt simulation capability.

Jan 1, 1994

By J. Greg Sanchez

The New South Ferry Terminal in the New York City Transit system represents an important milestone for the city. This is the first station designed and built in the 21st century. The design of the fire safety system included relying on Computational Fluid Dynamics to analyze the dispersion of heat and smoke, and modelling of people egress to determine the egress requirements. The project also looked into how to protect the structure from the heat exposure in order to meet the fire rating requirements. This paper provides an overview of the fire safety design approach taken to design the new South Ferry Terminal station in lower Manhattan and looks into fire modelling, structural fire protection, and station evacuation.

Jan 1, 2008

By C. B. Queja

Flexible synthetic membrane liners have become a standard facet to copper and gold heap leach pad design. While gold heap leach operations have utilized most types of synthetic liners, copper leach operations have commonly only been lined with polyethylene. The objective of this study was to determine if there are any chemical reasons why other synthetic membrane types could not be used to line a copper heap leach facility. With engineered consideration, the flexible membrane liner under the ore pile serves two purposes. The first provides a near impermeable boundary which aides greatly in the collection of the metal laden process solution. The second advantage to the flexible membrane is the almost non-permeable barrier to benefit increased environmental awareness that has led to an increase in solution containment technology. The Environmental Protection Agency (EPA) has developed a compatibility test for solutions and membrane liners. The EPA Method 9090 is intended for use in determining the chemical effects of a solution on the physical properties of the flexible membrane liner material intended to contain them. Data from these tests would assist in deciding whether a given liner material is acceptable for the intended application.

Jan 1, 1995

By G. W. Zhang

Ultra-fine Stirred Mill is a kind of high energy efficient equipment for ultra-fine grinding, and has been the mainstream equipment in the submicron powder and slurry industry. This paper mainly describes flow-field numerical simulation of the three popular ultra-fine grinding mills: (respective-ly as) Disc Stirred Mill, Pin Stirred Mill and Spiral Stirred Mill, by means of the software Computational Fluid Dynamics (CFD). In the flow-field numerical simulation, the velocity gradient, shear rate dispersion of the flow-field, the viscosity dissipation rate were analyzed with CFD. It is discovered that Pin Stirred Mill has the highest velocity gradient in circular directions and the most homogeneous distribution of shear rate among the three. Flow-field numerical simulation provides a new way (and means to) for the parameter optimization design and project enlargement of Ultra-fine Stirred Mill. The experiments were also carried out, the results are consistent with the results of the simulation analysis. For example, in GCC grinding experiments under the same conditions, the specific energy consumption of Pin Stirred Mill with 3600L in volume is 15%~17% less, and its processing capability is 13%~15% better than Disc Stirred Mill. Now with its optimized structure and excellent performances, more than ten sets Pin Stirred Mill with 3600L in volume have been used in industrial production in Shandong, Guangdong and Hunan province.

Jan 1, 2014