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By T. Tafi

The Ute-Ulay project area is located approximately five miles west of Lake City, in Hinsdale County, Colorado. The Ute-Ulay Mine site is approximately one mile east of the project area. The elevation of the site is 9,200 feet and is adjacent to Henson Creek (Figure 1) [ ] The Ute-Ulay Mining complex is an inactive gold, silver, and zinc mining/milling operation, that operated from the 1880?s until the 1970?s, and sporadically into the late 1990?s. The mining complex comprises several levels of underground mines, a flotation mill, and an abandoned town site. Due to the narrow, steep sided canyon, milled tailings were pumped upstream one mile in a sluice box to a wider section of the canyon, and deposited into five tailings impoundments and one berm located between the impoundments. An estimated 9,000 cubic yards (yd3) of fine grained tailings were located in the impoundments adjacent to the creek. The Ute-Ulay project area consisted of the mill tailings impoundments located upstream from the historic mine.

Jan 1, 2011

In general, the metallurgical industry has so far been slower than the chemical industry to adopt ion exchange materials for industrial processes. The atomic energy industry presents a marked exception to this general situation, and the literature shows a rapidly increasing use of ion exchange techniques for the recovery of atomic energy metals on scales ranging from the ultra micro up to that of the largest mining operations. In many cases, the processes used would be equally applicable to more common metals and it is hoped that this review will be of interest to metallurgists outside the specialised atomic energy field. The review is intended to describe developments of ion exchange processes made during the last three years. Earlier studies have been summarised by Kunin and Preuss (1956) and Roland (1957). In order to restrict the number of references discussed, purely analytical procedures have been omitted and only those processes which have been conducted on a reasonably large scale or which, from their nature, areclearly capable of being upscaled, have been considered. The paper is divided into five main sections concerning respectively:Water treatment and effluent disposal.Metal recovery and purification.New ion exchange materials.New ion exchange equipment.Membrane cells.WATER TREATMENT AND EFFLUENT DISPOSALA high proportion of atomic reactors, and particularly those of American design, are cooled by water which is...

Jan 1, 1961

By M. A. van Nierop

Load behaviour in an industrial mill has been measured directly by inserting probes through liner bolts. The data from conductivity probes have indicated the presence of premature centrifuging during manipulation of the load mass. Overloading conditions were also encountered. Overloading and premature centrifuging both reduce the power drawn by the mill. These effects have been successfully modelled.

Jan 1, 1997

By Deren Zhu

Based on the results of in-situ observations and physical model analysis, a computer simulation method, FEAEBP, has been developed to predict the behaviors of main roof breakage in longwall mining by considering it as a Kirchhoff plate on Winkler elastic foundation. This method in used to investigate the initiation, and development of the breaking process of main roof and its displacement field before and after its breakage. In this paper the simulation method is introduced, characteristics of the displacement field of the main roof is discussed and monitoring variation of the displacement field of the main roof in a Chinese longwall face is demonstrated.

Jan 1, 1989

By B. Hilscher, P. Nayak, N. Yoon

"The mining industry is currently facing challenges with declining feed grades and is struggling to find solutions to improve the project’s economic value. By means of pre-concentration, ore sorting aims to separate the barren material from the valuable ore to reduce energy consumption and tailings generation, while increasing the feed grade, concentrate grade, mill recovery, and revenue. In addition, ore sorting allows the modification of deposit geometallurgy in order to allow the creation of an optimal mill feed.This paper evaluates the applicability and challenges of ore sorting by utilizing the results from four different mines, and reviews them in detail. The mines include two underground and two open pit mines that are base metal and precioius metal operations. In order to understand the applicability of ore sorting in these operations, initial rock-by-rock test results and different types of assays (atomic adsorption [AA], inductively coupled plasma [ICP], and fire assay) are utilized. Using the assay results, the grade recovery curves for ore sorting are generated and they are further improved by using and developing an ore sorting algorithm, which is discussed in this paper. The application and evaluation of ore sorting in greenfield and brownfield properties will also be discussed.The state of the art ore sorting technologies for both rock-by-rock and bulk sorting are reviewed in this paper. The future technologies on the horizon, including different combinations of sensors, are explained. The sorting technologies include, X-ray transmission (XRT), X-ray fluorescence (XRF), colour, infrared, electromagnetic, and laser induced breakdown spectroscopy (LIBS).IntroductionOre sorting is a sensor-based sorting technique introduced between the excavation stage and processing stage, where the unwanted waste is diverted to the waste dump and only the ore is sent to the mill for further processing. As a result, the quality of the material entering the mill is improved and the dilution of the ore is reduced. In greenfield projects, sensor-based ore sorting provides an opportunity to reduce the capital cost of the project and increase the return on investment (ROI). With most operations currently facing the challenge of finding a high grade deposit, having a sorting unit provides several advantages while keeping the cost at minimum."

Jan 1, 2017

The effect of rare earth element Y (0-2.0at.%) on the microstructure of TiAl alloys at the as cast and rapidly solidified conditions has been investigated. The results show that the addition of Y greatly refined the microstructure of TiAl alloys at both conditions. The refinement is more significantly with higher Y content. The refinement of Y in the cast alloys is attributed to that the strip-shaped Y-rich phase locating on the grain boundaries impedes the grain growth during solidification. In the rapidly solidified alloys, Y-rich phase dispersing uniformly as spherical particles in the matrix acts as heterogeneous nucleation sites which increases the nucleation rate of ??phase during the ????phase transformation, and produces a refined initial microstructure during solidification. Higher cooling rate restricts the grain growth during subsequent cooling.

Jan 1, 2010

By Oscar Pereyra, Juan Galiano, Arlen Ventura, Elmo Quiroz

Este estudio se basa en el análisis de onda elemental para determinar los tiempos de retardo que reduzcan al máximo el PPV en las comunidades (campo lejano). Inicia con la toma de datos con equipos de medición de vibraciones (sismógrafo Instantel Plus) con lo cual obtenemos el registro de un taladro de producción; el que será analizado para determinar una relación de PPV versus tiempo de retardo. Con los retardos obtenidos del análisis de onda elemental, se programan los siguientes disparos y se toman los registros de vibraciones en la zona donde se quiere medir los niveles de PPV. Los proyectos de voladura que servirán para hacer el comparativo y determinar la efectividad de esta metodología, serán los proyectos de producción cargados con mezcla explosiva gasificada; tomando como referencia los disparos desde 2018 en adelante.

Sep 30, 2022

By Lloyd G. Fitzgerald

"The dangerous nature of explosives makes them a potential hazard wherever they are used, but they are likely to exercise their greatest harmfulness under conditions inherent in coal mining. The ease with which explosives can be detonated and the suddenness and violence with which they detonate require great care in their handling and use, if acci-dents are to be avoided. Campaigns have been waged by the manufacturers, the Federal Bureau of Mines, coal-mining companies, and other agencies to educate users of explosives in their dangers and in their proper use and care.Probably 95 percent of the explosives accidents can be attributed to poor judgment, carelessness, negligence, or chance taking. In many explosives accidents it is difficult to determine the cause definitely, as the evidence of the origin is destroyed by the blast and frequently those involved have been killed. Survivors of the accident often are of little help in determining the cause, as the accident occurs so suddenly they cannot tell what happened or prefer not to divulge the information they have because it may point to their own carelessness.A survey has indicated that about 10 percent of all fatalities in coal mines were caused by explosives accidents (excluding gas and dust explosions initiated by explosives). A list of explosives accidents by States, from 1925 to 1932, classified according to the severity of the accidents, indicated that Kentucky and Wyoming had the greatest number of fatalities resulting from explosives accidents. Records of the Bureau of Mines show that 14 coal-mine explosions occurred from January 1 to June 1, 1943. Explosives were involved in four of these explosions. Black powder caused two of the accidents and permissible explosives used in a nonpermissible manner the other two. These statistics are mentioned to show that explosives are still causing severe accidents.Elimination of the hazards associated with explosives begins on the surface. Storage magazines should have no opening, except for entrance and ventilation; ventilators should be screened effectively to prevent the admittance of sparks as well as to prevent unauthorized entrance. The interior should be kept clean and dry, and the floor should be of nonsparking material with no metal exposed. The surrounding area should be kept free of combustible material for not less than 25 feet (and preferably 50 feet) in all directions. Storage magazines should be fire-resistant and reasonably bulletproof."

Aug 1, 1944

Norton Co., a manufacturer of abrasive products and diamond drilling and coring bits for oil and gas exploration, is building a $19.1 million addition, scheduled for completion in late 1980, to the Huntsville, AL. The plant makes alumina-zirconia abrasive grains used in grinding wheels and coated abrasives. ALUMINUM Martin Marietta Aluminum Inc. announced plans to expand production capacity of its 112,000-ton-per-year primary aluminum smelter at Goldendale, WA to 177,000 tons per year. The $125 million expansion was scheduled to come onstream in 1981. The Aluminum Company of America announced plans to restart a fourth potline during October at its 185,000-ton-per-year Point Comfort, TX primary aluminum smelter.

Jan 1, 1979

Analysis for pillar extraction potential (A-PEP) is an intelligent tool, which could be used as a preliminary output indicator when considering the secondary extraction of regional support pillars in the Witbank and Highveld coalfields of South Africa. The safe and economic extraction of underground coal pillars is of paramount significance and importance to the South African coalmining industry to ensure continuity of supply of this fossil fuel. Pillar extraction practices in South Africa have been responsible a significant proportion of safety and fatality statistics in relation to its relative output (less than 5 per cent of total South African coal production) and, as a result, research was undertaken in local pillar extraction operations and extended to similar operations in New South Wales, Australia to assess a way forward for pillar extraction in South Africa. It was found that, although little in the way of new technologies has emerged in this field in the recent past, significant contributions could be made in the field of risk analysis to obtain a generic design methodology for pillar extraction in South Africa. The resultant A-PEP tool to assess pillar extraction potential is based on certain physical, risk and economic factors, which combine to indicate operational success in terms of economic, health and safety attributes. At the time of A-PEP?s development there was alack of operating underground coal pillar extraction operations, which made it difficult to validate its applicability. Since then, however, A-PEP has been successfully tested and validated against two unique underground coal pillar operations, which is the discussion of this paper. One operation is situated in the Witbank coalfield and is extracting pillars, which are 20 years old and at a depth of 80 metres below surface, while the other operation is situated in the Highveld coalfield-which is extracting 6 month-old-pillars underneath a massive dolerite sill at a depth of 220 metres. A-PEP has shown that its predictive nature is consistent the workings at both operations, irrespective of their unique conditions, and as such it can be successfully used as a mine planning tool. The A-PEP mine planning tool thus represents a positive step toward an integrated approach to underground coal pillar extraction when considering legal and operational aspects, which could form the basis for legislative guidelines when considering the future of pillar extraction in South Africa.

Jan 1, 2005

By I. A. Mutemererwa

This paper investigates the role of vertical integration between chrome ore mines and ferrochromium smelters in the location of ferrochromium production capacity in South Africa and Zimbabwe. Vertical integration is important in understanding the increasing competitive position of these two countries as observations show that an increasingly larger share of the global market has been coming from integrated producers. The paper argues that the increased vertical integration between mines and smelters in South Africa and Zimbabwe has led to a lower cost of chrome ore as an input compared with other producers. Underlying this hypothesis is the basic tenet that, more likely than not, production will take place where the costs are lowest. The paper concentrates on high carbon ferrochromium (HCFC) production in market economy countries (MEC). Using an ordinary least squares model, the study tests the relationship between low chrome ore costs and vertical integration shows a statistically significant relationship. These findings partially support the view that the control of sources of chrome ore is a major source of competitiveness. Keywords: competitiveness, ferrochromium (ferrochrome), ordinary least squares, dummy variables, vertical integration, southern Africa.

Jan 1, 2000

By Williams K. C

This paper presents a brief account of the plant which has been developed at Port Pirie to recover, by vacuum distillation, the greater part of the zinc content of desilverized lead. The present plant is an experimental unit, which is run in conjunction with the normal refinery practice, but can be cut out of the circuit. It will shortly be dismantled and duplicate units will be built on the sites chosen for the final plant installation.The unit described here has treated flows of 16 to 37 tons per hour of desilverized lead, to recover 90 to 95 per cent of the zinc contained in it. It is not intended here to detail all aspects of the vacuum dezincing operation, nor the developments which precededthe adoption of this design. The essential features of the present plant will be described and, where these are peculiar to the present experimental location, the intended alteration for the final plant will also be mentioned. OUTLINE OF PLANT AND PROCESSLead issues from the continuous desilverizing kettle at about 350° C. containing about 0·57 per cent Zn. It is conveyed by a tiled launder to the preheater, where it is heated to 580-620° C.Hot lead from the preheater enters the vacuum vessel via a barometric leg. From a reservoir holding about 19 tons of lead it falls by gravity in a thin film exposed to high vacuum (20-50 microns)3 and leaves the vessel via a barometric leg, entering the lead pot. The lead leaves this pot at 540-560° C., containing 0·03 to 0·06 per cent Zn, which is removed, together with residual antimony of 0.02 to 0·06 per cent, by a separate final refining process.

Jan 1, 1956

More than 100,000 people are expected to be in Las Vegas, NV in March for ConExpo-Con/Agg 2002, the largest exhibit of its kind in the Western Hemisphere. This triennial event features equipment, services and technical sessions geared toward the global construction aggregates and ready mix concrete industries. ConExpo-Con/Agg 2002 will take place March 19-25, 2002 at the Las Vegas Convention Center. For registration information, contact the show offices, phone 800-867-6060, 414-298-4141, or 301-587-3140, Website www.conexpoconagg.com.

Jan 1, 2002

By O. P. Hood, R. H. Kudlich

When a gasoline locomotive is used in a mine there is danger of the noxious gases of the exhaust vitiating the air, but if enough air is circulating in those parts of the mine in which the locomotive is used, these gases are so diluted that they are rendered harmless, and the health of the workmen is not affected. In some mines the use of gasoline locomotives is impracticable, though in the majority of mines where they have been tried they have proved to be safe and economical. To determine the limitations that should surround the use of these machines in mines so that they shall not be detrimental to health and so that their economic advantage may be retained, it is necessary to ascertain the volume and the character of the exhaust gases and the amount of these gases that may be safely allowed in the mine air, and also to determine safe conditions of operation. The problem is primarily one of ventilation and like all ventilation problems must be intelligently computed to meet the conditions of each mine. The investigation described in this bulletin was undertaken 'by the Bureau of Mines in an endeavor to obtain exact information on some of the basal questions involved in the use of gasoline locomotives in mines, this investigation being one of many that the bureau has been conducting in its efforts to increase safety and efficiency in mining.

Jan 1, 1915

In the 1980s and?90s the gold mining industry in South Africa came under pressure from the continued poor dollar gold price and escalating Rand based costs, furthermore the external impacts on the industry were changing. Thus, the Chamber of Mines (COM) shifted its focus away from many historical areas of support towards the new industry challenges in safety and health, labour markets, environmental responsibility, mineral rights legislation and social responsibility. During 1997 the lack of funds and the changes facing the tertiary institutions were often subjects of discussion at the various sub-committee meetings. The Metallurgical Sub-committee of the Chamber Education Fund or the Sub-committee of Consulting Metallurgists as it was known identified the need for the funding structure to change with the times. Up to this time the Chamber of Mines operated an Education Fund that supported mining industry academic departments at various South African tertiary institutions; these funds were derived exclusively from the country?s gold and coal mines the basis of Chamber membership. Funds of less than R5 million per annum were available for distribution by the three disciplinary sub-committees of mining, metallurgy and geology.

Jan 1, 2003

By D. D. Ndenguma

This investigation compares the results from an experimental and numerical study of air flow in a scaled-down underground coal mine model. This was done in order to determine if numerical analysis can be relied upon when searching for ventilation solutions to control high concentration of coal dust and methane gas in underground coal mines. Steady state analyses were used to identify flow patterns and recirculation regions within the mining section while transient state analyses were used to determine the time taken to extract the initial air from the model. The agreement between the experimental and numerical results indicates that numerical modelling is useful in this regard. The study went further to devise a method of determining the optimum position of the jet fan that is responsible for mine-gas dilution at different stages of mining.

Jan 1, 2014

Experiment of Improving the Quality and Decreasing the Impurity of Titanium Concentrate in Panzhihua Mine in China

Sep 13, 2010

By J. M. A. Geldenhuis

This work is concerned with studying possible reactions in the ilmenite furnace which may control the product quality of both slag and metal. Two different approaches were followed: comparing actual furnace slag compositions with the calculated equilibrium values and using commercial oxygen probes to measure the effective partial oxygen pressure in the slag and metal. It appears from a comparison of actual furnace slag compositions (in terms of the distribution coefficient of vanadium) with equilibrium values, that the TiO1.5-TiO2reaction may fix the effective partial oxygen pressure for the vanadium reaction. This possibility was tested using commercial oxygen probes (traditionally applied during steelmaking) to measure the effective oxygen partial pressure of both the slag and liquid iron in Iscor?s 3MVA pilot plant ilmenite furnace. From these measurements, it appears that commercial oxygen probes containing zirconia solid electrolytes can be used to measure the effective oxygen potential of both the slag and liquid iron. This oxygen activity correlates well with the FeO content of the slag. The results, furthermore, clearly illustrate that equilibrium conditions are not attained in the ilmenite furnace during the production of high titania slags, since the effective oxygen potential of slag and metal differ substantially.

Jan 1, 1999

A series of fault slip seismic events have occurred at Garson mine. The events have occurred during development advancement exposing faults, after the extraction of single stopes due to mining induced stress change, and due to time effects after delays of many days during which no mining had been conducted. This paper discusses the study completed consisting of a global or holistic approach aimed at mitigating some of the risks associated with the structurally controlled rockbursts at Garson. Background Garson mine is located in the south east area of the Sudbury Basin (Ontario, Canada). Mining occurs in two main ore bodies (the #1 Shear and the #4 Shear) which are copper-nickel-sulphide and occur within shear zones that (as well as the ore bodies) strike approximately east-west and dip steeply south. From the north (footwall), lithologies progress (Figure 1a) from norite (NR), to greenstone (GS), and finally to meta-sediment (MTSD). A generally WNW-ESE striking, bifurcated sub-vertical dyke of olivine diabase (OLDI) cuts the series. The current active mining block at Garson is between 4700L and 5100L (levels denote depth in feet below surface).

May 1, 2009

By S. E. Pérez-Fontes

An experimental study on the oxidation of chalcopyrite (CuFeS2), pyrite (FeS2), covellite (CuS) and chalcocite (Cu2S) particles was conducted by means of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) techniques. The oxygen concentration in the process gas was set to 40% and 70% (by volume) and a heating rate of 40°C/min was used. Response variables included the temperature of incipient reaction, the total exothermic heat of reaction, particle mass, morphology and mineralogy of the reacted particles. Based on the experimental data and phase stability calculations, reaction mechanisms were proposed to represent the behavior of the particles during oxidation. The reaction mechanisms were verified by X-ray diffraction (XRD) analyses of the oxidized particles and by thermochemical and mass balance calculations to reproduce the DSC and TGA data. Overall kinetic models were developed to represent the evolution of the exothermic heat of reaction as a function of time.

Jan 1, 2007