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Copper Extraction from Scrap Cables by Biotechnological Means

Sep 13, 2010

By Ch. D. Taylor

Past studies with blowing face ventilation systems have shown that using a machine-mounted scrubber and water sprays can reduced methane levels at the face. The current research was conducted to determine how the sprays and scrubber interact to reduce methane levels, and what spray configurations provide the best face ventilation when used with a scrubber. Testing was conducted in a ventilation test gallery designed to simulate a full-scale mine entry. In the entry, a model mining machine, equipped with a simulated dust scrubber and water spray systems, was located at the face of a 6.1 m (20 ft) box cut. Face ventilation was provided by a blowing curtain located 12.2 m (40 ft) from the face. Methane released from a manifold at the face was measured at six locations near the face to compare the ventilation effectiveness of the spray systems while operating with and without the scrubber. Airflow movement across the face was affected by the spray configuration and scrubber operation. Average face concentrations were lowest when directed sprays were used with the scrubber. Varying the direction of the scrubber exhaust affected face methane levels.

The Northland region of New Zealand has a complex geological history which has long been the subject of considerable controversy. Small mineral deposits have been discovered in the past, and some have been mined. Except for aggregates and very high quality china clay, mining is virtually nonexistent at present. Mercury mining is proposed from small deposits in the Kaeo area. Intensive exploration for epithermal precious metals deposits in the past seven years, combined with some recent geological mapping undertaken by the Geological Survey and University thesis students has added greatly to an understanding of Northland's geology. Mapping of the Whangaroa-Kaikohe map sheet at a scale of 1:100 000 by Brown and Laurenson Limited has enabled new geological information to be collated for the first time since 1961, when the last geological map was published. The 'Northland Allochthon' is now observed to be a series of four or more thrust sheets each containing predictable formations. High angle faulting contemporaneous with overthrusting has modified the thrust sheets, and established a series of horsts and grabens. The Pirau Fault is considered to be a major earth fracture.

Jan 1, 1987

By James M. Link

Underground coal mining is the most hazardous industrial occupation in the United States.. Haulage accidents in underground coal mines contribute substantially to the occupational hazards of this type of work. In an effort to improve mine safety, a completely hydraulic transport system has been designed to move coal from the mine face to the preparation plant. The capital investment for the hydraulic haulage system is great, and the size of the mine developed for this study is large. Mine production for the conventional haulage mine is 1. 1 million tons of clean coal per year, while the hydraulic haulage mine will produce over 1.6 million tons of clean coal per year. Safety statistics for a number of mines of this size are shown.

Jan 1, 1975

By Malcolm Arnesen

Mineral Resource Management (MRM) is a business concept with the purpose of increasing throughput by management of key process variables to optimize ore utilization. To achieve a MRM process focus there are four principles that need to be applied to the business. In this sense, the paper define these principles and describe how they are applied to the mining business using Thabazimbi iron ore mine as an example. Also the article deals with the generic approach to Mineral Resource Management and the second part with the application and success of MRM at Thabazimbi Iron Ore Mine.

Jul 17, 2000

By Thomas M. Barczak

Wood cribs are used extensively to stabilize openings in underground coal mines. This U.S. Bureau of Mines report describes the results of full-scale testing of several multitimbered wood crib configurations. Multitimbered configurations are wood cribs that are constructed with two or more timbers per layer. Nine different crib configurations were evaluated. Configuration parameters under study included the aspect ratio (height-to-width relationship) and the percentage of solid rr:aterial used in crib construction. Test results and generalized wood crib behavior are discussed and recommendations are made concerning crib constructions to maximize strength and stability. Crib performance is enhanced by reducing buckling effects by decreasing the aspect ratio and geometry considerations that increase the moment of inertia. A cost benefit analysis of multitimbered wood crib configurations is made. Generally, increasing the percentage of solid provides more resistance at less unit construction cost. A comparison of laboratory results and underground observations of several wood pack wall supports suggest in situ load capacity is less than that measured in laboratory testing. Reasons for the apparent decrease of in situ load-bearing capability include load rate effects, stiffness of reaction surfaces, and varying boundary conditions that alter the load transfer mechanics of the crib structure.

Jan 1, 1991

By E. C. Westman, F. J. Shreve

This paper presents the design and construction of a multi-channel geophone array that improves tomographic imaging capabilities in both surface and underground mines. Especially important in the design of the array is sensor placement. Three issues related to sensor placement are addressed in this paper: 1) sensor placement in long, horizontal boreholes, 2) development of simple, robust, MSHA-acceptable clamping unit, and 3) orientation of the geophones within the borehole. Improved imaging capabilities will produce energy, environmental, and economic benefits by increasing exploration accuracy and reducing operating costs.

Jan 1, 2002

As mine haulage vehicles become larger, the danger to a driver during a fire emergency is increased by the greater height of the cab above ground. Also, property damage due to fires on bigger trucks can be substantial. To solve this problem, the Department of Interior's Bureau of Mines, through two research and development contracts with FMC Corporation, San Jose, California, has developed two reasonably priced, reliable automatic fire sensing and suppression prototype systems for large haulage vehicles. At the onset of the large mobile equipment fire protection contract effort, it was learned that fires were frequently experienced in open-pit mine haulage equipment, especially large trucks. As the size of equipment has grown, so has the hazard presented to an operator forced to leave his truck in a hurry when fire breaks out and his normal path to the ground is blocked by flames. His only recourse is to jump from the cab platform to the ground, and the one-story drop of 10 feet or more can severely injure him. It is with these factors in mind that a program was undertaken to provide a fire detection and extinguishing capability tor the large mobile equipment, especially trucks, used in open pit mines.

Jan 1, 2012

By A Brzovic, E Córdova

In an underground mine, different mining activities such as undercutting and cave progression generate redistribution in the present in situ stress field, and these changes are represented in the rock mass through induced seismicity.In order to study and analyse the induced seismicity generated in El Teniente, a block model was developed to account for the dissipated seismic energy through different areas of the mine from 1992 to 2015. More than 2.1 million seismic events were unified and classified in 3D in order to be used for the interpolations. The resultant model variables account for the accumulated energy releases in a monthly time resolution, and provide the ability to intersect different 3D entities with the stored information in the blocks, and estimate the energy evolution inside these entities.The generated model was used to analyse the geotechnical variables that determine the seismic response for the rock mass in the mine, such as geometry and direction of advance of the undercut fronts, lithological domains, and to study the ‘work’ the rock mass needed to go through in order to generate caving in areas with different stress settings.A specific area of the mine under high-stress conditions was analysed by studying the seismic energy associated with two subsidence caves interacting around the project, the modelled lithology. Using the same approach two adjacent projects are analysed to understand the released energy from the rock mass based on different stress and geotechnical settings for each project.CITATION:Córdova, E, Brzovic, A and González, R, 2016. Analysis of progressive seismicity and its correlation with geotechnical variables at the El Teniente Mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 835–844 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

Publications on hard rock tunnel support design in the South African mining industry have originated primarily from the goldmines during the past 50 years. Little has been published to date on the platinum and chrome mines of the Bushveld Complex. This paper covers the search for a suitable design methodology for off-reef tunnels at Impala Platinum Mine, situated on the Western Lobe of the Bushveld Complex. The fall of ground accident statistics for off-reef excavations of the mine are presented and the available rock mass quality evaluation systems are reviewed. The Q-Tunnelling Quality Index (or Q-Index) is selected because it assesses the important driving factors behind falls of ground at Impala. Two off-reef excavations are evaluated using the Q-Index, and it is shown that minor modifications are required for implementation at Impala. It will take some time before support design throughout the mine is based on the outcome of proper geotechnical investigations based on the Q-Index. Widespread implementation of such support designs should help to solve the fall of ground problem in off-reef excavations while at the same time reducing support costs.

Jan 1, 2002

By I. A. Minaev

The conditions of a stability of metallurgical films on a surface of solid on the basis of classical regularities of a thermodynamics are considered. For specific conditions of metallurgical processes the basic equations relevant to non-metallic inclusions (product of steel killing) migration and transfer through the interface boundary of metal-slag are obtained. The basic criteria equations of conditions of stability of metallurgical dispersed systems are developed in view of films formation. The probable thermodynamics reason of wetting due to formation of stable films are discussed. The experimental measurement of thin and thick films elastic resistance for metallurgical systems are carried out and the results are discussed. The presence of a wetting thick film increases stability of dispersed systems (facilitates an inverse implication of non-metallic inclusion in a melt) due to a barrier effect of wetting films. The quantitative evaluations of non-metal inclusion stability for steel in contact with any metallurgical slag are carried out. The results are in accordance with technological experience. Keywords: Inclusion removal, Film thermodynamic, Slag-metal dispers system

Jan 1, 2004

By Jerry J. Ran

In open stope mining borehole deviation is one of the main factors affecting the blasting results. Though previous research has identified some actual deviation patterns, these studies are unable to relate the hole deviation pattern with the blasting results and therefore it is not possible to modify the design or take remedial measures based on the prediction of the blasting results. An alternative to the conventional method for borehole surveying is the in-hole probing techniques. With their inherent errors, it is important to evaluate these surveying systems under conditions of different mine sites. The lack of available assessment methods has limited the application of these techniques. In this paper some of the characteristics of the actual hole deviation pattern are discussed based on data from surveying production holes in six stopes. A method of predicting the blasting results is proposed by considering the borehole deviation pattern. Based on the prediction stope design can be modified or further surveying is carried out to improve the blasting results. The tolerable error is introduced to relate the surveying error with the drilling pattern and therefore it is possible to assess various in-hole-surveying techniques.

May 1, 2002

By L. Holappa

Ferroalloys like FeCr and FeMn are mostly produced in submerged electric arc furnaces. Typical for these processes is that the amount of slag is quite high. The role of slag for the process is thus very essential and specific chemical, physical and electrical properties are required. Slags in FeCr process are Al2O3-MgO-SiO2based with minor contents of CaO and CrOx. Slags in FeMn process are principally similar originating from silicate minerals but can have quite a large composition range depending on the manganese ore and its gangue minerals. Characteristic for FeMn process is that the slag is rich in manganese oxide up to above 30%. A common feature is that the ?ore oxides?, CrOx and MnOxin slag are not only divalent oxides but also containing some higher valent of Cr3+ and Mn3+, respectively. In FeMn production conditions the slag consists mainlyMn2+. This is a clear difference from CrOx containing slags in which both two and three valent coexists in slags in FeCr process conditions. Oxidation state of the slag depends on the ambient oxygen partial pressure and temperature in the examined process. Thermodynamics of slags in ferroalloys production are discussed in terms of phase diagrams, activities and oxidation state of chromium and manganese oxides. Further, slag properties influencing reduction kinetics and furnace operation i.e. viscosity and electrical resistivity are discussed. Keywords: review, slags, ferroalloys, ferrochromium, ferromanganese, thermodynamics, physical properties.

Jan 1, 2004

By Mark Svinkin

The purpose of this paper is to present an overview of recommended existing criteria of ground vibrations generated by blasting. It is shown that these criteria have limited liability because they were found for specific categories of structures. A new approach based on measurement of structure vibrations is suggested for assessment of damage in structures subjected to blasting vibrations. This approach provides the flexibility of implicitly considering a variety of soil-structure interaction and structure conditions. It is explained a new frequency-independent safe-level criterion of 51 mm/s (2 in/s) for the PPV of structural vibrations. Attention is brought to use seismographs properly calibrated for the required frequency range. Positive flexibility is demonstrated in assessment of structure and component of concern vibrations from blasting.

Jan 1, 2003

By Paul G. Swanson

This investigation was conducted to identify the principle causes of spoil instability problems in the Eastern Coal Province. The study was also conducted to develop a matrix to predict the strength and groundwater parameters necessary to conduct stability analyses on a proposed reclamation scheme. Suggestive methods to reduce spoil instability potential are also included. Numerous physical property, strength, compressibility, chemical and mineralogical tests were conducted on mine spoil samples obtained from 11 different surface mine sites. Site characteristics that influence the position of the post reclamation groundwater table were identified. Distinct regions within the Eastern Coal Province with high incidences of surface mine slides or high landslide susceptibility were identified. The application of the predictive matrices developed in this study is for surface mine sites mined and reclaimed in general accordance with the Surface Mine Reclamation Control Act of 1977. A review of current mining practices and the relative effect on spoil stability is included.

Jan 1, 1983

By M Lipalile, A B. Tunono, A W. Naismith

Konkola No 3 shaft experienced severe mining induced stress and time related deterioration in ground conditions in an area where an over-cut and bench (OCB) mining method was used to extract a shallow dipping wide orebody. This caused an unacceptable risk for safe mining operations to sustain the required levels of production. After a review of the conditions it was decided to change the mining method to CASCADE to recover ore in the affected area and modify the OCB method and use a modified over-cut and bench method (MOCB) for new mining sections. This paper describes the geotechnical criteria included to derive the mining standards for the MOCB. The geotechnical risks are identified and taken into account to develop stope design parameters, stoping sequences and support requirements. A monitoring programme to assess conditions as mining progresses is also discussed.

Jan 1, 2005

By H. Kose

In this research, a model quarry with an annual production capacity of 1 000 000 tonnes has been studied for both pit and hillside quarry cases with constant overall slope angle and variable bench slope angle, considering road grades of 8 per cent and 10 per cent. First, technical requirements have been determined and then the effect of production parameters, such as hole diameter, type of quarrying (pit or hillside) and road grade, on the cost has been investigated to determine bench height. Based on the results, it has been concluded that hole diameter has to be kept large in both pit and hillside quarrying to reduce drilling unit costs. In addition, in order to take advantage of gravity and reduce transportation cost, it has been suggested that bench height and road grade have to be kept high and low respectively in the case of hillside quarrying (downhill transportation) while, in the case of pit quarrying (uphill transportation), bench height and road grade have to be kept low and high respectively, in order to transport the blasted material to a lower height and distance, to save energy, thus decreasing the transport cost. Keywords: Quarry, pit, hillside, road grade, bench height

Jan 1, 2005

By D. Geoffry Minnes

Nepheline syenite is a silica deficient crystalline rock consisting of albite and microcline feldspars and nepheline, together with varying but small amounts of mafic silicates and other accessory minerals. Nepheline-bearing rocks are widely distributed around the world but only in Canada, Norway, the Union of Soviet Socialist Republics, and the United States are deposits worked commercially. Because of its low melting point and fluxing ability, nepheline syenite was investigated in the early 1900s by many students of glass and ceramics. Although the nepheline syenite deposits in Methuen Township, Ont., Canada, were discovered as early as 1897 it wasn't until 1935 that the first mill was erected to produce nepheline syenite products. In Canada, nepheline syenite deposits are worked by Indusmin Ltd. and International Minerals and Chemical Corp. (Canada) Ltd. who have combined production capacity in excess of 1800 tpd. Between 1935 and 1972 seven million tons valued at $78 million were produced from the Methuen Township deposits. In Norway, the Norsk Nefelin Div. of Elkem Spigerverket has produced nepheline syenite from a deposit on Stjernoy Island in western Finnmark since early 1960. Between 1961 and 1972 the company produced 930,000 mt with an estimated value of $17 million. Nepheline syenite has been under investigation in the Union of Soviet Socialist Republics (USSR) since at least 1928. In 1951 the first commercial alumina works was brought on stream at Volkhov, near Leningrad, utilizing nepheline concentrates from the Kola peninsula as mill feed. Since then two others have been completed and more are planned. Large quantities of portland cement, sodium carbonate, and potassium carbonate are produced in conjunction with the alumina. In the United States, nepheline syenite has been produced for many years from deposits in central Arkansas by the Big Rock Stone and Materials Co. for construction aggregates and, since 1947, for roofing granules by the 3M Co. Chap. 16 on "Feldspar, Nepheline Syenite, and Aplite" in the 3rd ed. of Industrial Minerals and Rocks (Castle, and Gillson, 1960) and Nepheline Syenite Deposits of Southern Ontario (Hewitt, 1960) contain excellent accounts of earlier commercial development of nepheline syenite as a glass and ceramic material. Therefore this chapter deals mostly with the period since 1960 and with matters not previously reported in detail. An English monograph on Nepheline-Syenite and Phonolite (Allen et al., 1968) is a complete current survey of nepheline syenite which, with its very complete list of references. is an excellent source book. End Uses Nepheline syenite from the Canadian and Norwegian producers finds use primarily in the manufacture of glass and ceramics. One producer also makes several grades of nepheline syenite that are useful as extender pigments and fillers in paint, plastics, and rubber. In the Soviet Union nepheline is used in increasing quantities in the manufacture of alumina, alkali carbonates, and portland cement and to a lesser degree it is used in the manufacture of colored container glass.

Jan 1, 1975

By J. J. Demeter

Experiments were conducted in 2- and 4-inch-diameter standpipes to evaluate the effectiveness of standpipes as pressure seals. During the experiments, these standpipes conveyed Alan-Wood magnetite (60 to 230 U.S. standard sieve mesh) by gravity flow from one vessel to another of relatively higher pressure. The information obtained has been helpful in a Federal Bureau of Mines investigation of how to make either synthesis gas or hydrogen by a modified steam-iron process employing a continuous recycling stream of granular iron-iron oxide at temperatures of 600° to 900° C. In this process the mixture of granular material flows by gravity from a reduction vessel at low pressures to an oxidation vessel at higher pressures. Data from the 2- and 4-inch-diameter standpipes indicate that it would be practical to use a standpipe as a pressure seal between the reductor and oxidizer. Investigators found that, by gravity flow, the standpipe could convey the Alan-Wood magnetite against pressure gradients up to 1.07 pounds per square inch per foot of column height.

Jan 1, 1961

By J B. Taylor

Geographic Information Systems (GIS) are being increasingly used by the mineral exploration industry in the search for new ore deposits. A mineral exploration GIS links geological and geophysical data by virtue of their geographic location in a digital map setting. Geological and geophysical data are categorised into a number of themes or layers within a mineral exploration GIS. These layers may include polygonal information such as rock type and tenements, line information such as faults and fold axes, point information such as mines and mineral occurences, and images such as gridded geochemistry and aeromagnetics. A mineral exploration GIS is a powerful tool to help the explorationist comprehend the spatial associations and interrelationships of his/her data. These spatial associations can be integrated with a mineral genesis model, to create a mineral prospectivity map to more effectively target exploration. Arguably a competent geologist who has a good understanding of the genesis of the local ore deposit types and knows their local geology backwards could intuitively derive a mineral prospectivity map. However, in an era of rapid data accumulation from many different disciplines, the ability to assimilate and understand is a huge task for any individual. A mineral exploration GIS enables the explorationist to spend more time analysing data and testing ideas, rather than finding and manipulating data into compatible formats.

Jan 1, 1994