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A field method combining solvent extraction and paper partition chromatography permits a simple and rapid semiquantitative estimation of gold in siliceous, argillaceous and sulphide ores. The method will facilitate the eyaluation of prospect samples in which the gold is too fine for separation by panning.Ethyl alcohol-hydrobromic acid mixtures are suitable for chromatographic development of the gold complex, and give clear reproducible definition of the gold zone. Substitution of commercial "methylated spirits" for the ethyl alcohol gives equally good definition, improving the potential of the method for field use.A batch of six samples in the range of 0·5 to 5·0 dwt/ton can be completed in two hours. The range may be extended by simple modification to higher or lower values.INTRODUCTIONIn a chromatographic method described previously (Lever 1958, Nevill and Lever 1959), gold from a standard volume of ore clamped between -plate glass was extracted by aqua regia on to the paper. After cautious drying the chromatogram was developed by an ethyl acetate-nitric acid-water mixture and gold was identified by spraying with stannous chloride solution. Sensitivity of the method in the low range was poor. The brown line obtained in the 1-3 dw/j ton range, caused by movement of gold in the reduced form, was not considered to be a satisfactory confirmation of the presence of gold. It was felt that the method would be improved by using a more elegant extraction and applying developing conditions which would produce a well defined purple line at all gold values. Iron was a limiting factor, and a method of eliminating its interference was needed.The method now developed overcomes these shortcomings, and gives a reliable result with a purple line for assay values of 0·5 dwtjton and over. Gold is dissolved from an...

Jan 1, 1964

Statistics on the imports of industrial minerals into the EECshow that the traded volume in 1987 is approximately 23 million tonnes.The following table documents the imported quantities on the most important industrial minerals.

Jan 1, 1989

By Don Phelps, Dean Brox, Peter Procter, Andy Saltis, Tom Morrison, Jeff Pringle

The Greater Vancouver Water District is currently constructing the Seymour-Capilano Water Filtration Project to enhance the quality of drinking water in the Vancouver metropolitan area. The Seymour-Capilano Water Filtration Project comprises the 1,800 million litres per day Seymour-Capilano Filtration Plant, the 1,080million litres per day Capilano Pumping Station, twin tunnels with associated shafts, and the Capilano Energy Recovery Facility. The twin tunnels will convey raw water under pressure from the Capilano Reservoir to the Seymour Filtration Plant and return treated (filtered) water for distribution. The Twin Tunnels component of the project comprises twin, 3.7 m diameter, 7.2 km TBM bored tunnels, the 180 m deep Seymour Shaft as the main launch shaft, and two 4 m diameter, 268 m deep raise bore exit shafts at Capilano. The Twin Tunnels have been planned as predominantly unlined tunnels sited at depth entirely within granitic bedrock and cross under two major buried glacial valleys of breadths in excess of 1500 metres that are filled with glacial sediments to depths up to 200 metres. The maximum overburden along the tunnel alignment is approximately 400 metres. Comprehensive site investigations and studies were completed during the detailed design stage of the project. The construction of the twin tunnels started in the fall of 2004 and is planned to be completed by mid-2008.

Jan 1, 2005

By Daniel N. Adams

The University Link project extends Seattle?s light rail from downtown to University of Washington (UW). It includes 5.0 kilometers (3.15 miles) of twin-bored, 6.4 meters (21 feet) excavated diameter tunnels, and two cut-and-cover stations. The Capitol Hill Station (CHS) requires an excavation 170.7 meters (560 feet) long, 22.6 meters (74 feet) wide, and 22.9 meters (75 feet) deep. The University of Washington Station (UWS) requires an excavation of about 238.4 meters (782 feet) long, 21.3 meters (70 feet) wide, and 33.5 meters (110 feet) deep. The project is within the glacially diverse soils of the Puget Sound region, below groundwater. This paper highlights major station and tunnel design elements, including the approach to support of excavation at both station boxes, and the site staging requirements.

Jan 1, 2008

By Jan A. Nilsen

This paper describes a key element in the construction of a major project undertaken by Harbourfront Corporation in its efforts to rejuvenate the central Toronto waterfront. The Spadina Pier forms one of the two major structures of the $10 million marina complex. Completed in early 1986, the 150 metre(490 ft.) long by 43 metre(140 ft.) wide pier structure will contain a 320 car parking garage as well as providing the foundation of a 17-story residential tower and a two-story retail/commercial complex. However, the pier structure posed a considerable challenge to its developers due to the the many restrictions imposed on the site by the environmental authorities which ruled out the construction of dykes or the placing of other fill materials on the highly contaminated bottom sediments. In addition, access at the site was restricted by its proximity to the main harbour navigation channel and a grain elevator berth. The original design called for a cofferdam to form an integral part of the finished structure. However, the contractor chose to regard the cofferdam as a temporary structure and proposed to construct the pier in the dry by enclosing the 10,000 square metre(107,600 sf) site with a 450 metre(1480 ft.) long single wall steel sheet pile cofferdom 7.5 metres(25 ft.) from the final pier structure. This paper will describes the design and construction of the cofferdam. Prior to finalizing the pier design, a geotechnical investigation of the shale bedrock was undertaken as well as a small sheet pile test cell program to evaluate the feasibility of driving a Canadian manufactured cold-rolled sheet pile into the bedrock. Relying on the design parameters for the shale bedrock, Foundation designed the cofferdam utilizing a post-tensioned bipod bracing system to resist a 7 metre(23 ft.) hydrostatic head as well as the maximum wind and wave forces expected at the site. The bipod bracing system consists of diagonal H-pile raker piles and verticle pipe piles anchored to bedrock with post-tensioned anchors grouted into bedrock.

Jan 1, 1987

Operational effectiveness is fundamental to any operation, becoming highly topical in those experiencing less than optimal output from their fleets. It is all encompassing aiming to identify those factors that could be improved within production and suggesting solutions in order to optimise the existing fleet and obtain the greatest capital return on expenditure.Argyle Diamond Mine (ADM) is a large open cut diamond mine located in the East Kimberley region of Western Australia, approximately 180 km south of Kununurra. It is owned and operated by Rio Tinto on a two week on/two week off roster fly-in/fly-out from Perth or drive in/drive out from Kununurra. Through benchmarking the operation between January and June 2002, a study was undertaken allowing identification of areas falling below target. Following this, analysis of annualised hours and production downtimes were undertaken to quantify the potential gains of improvements in these areas. Strategies were then identified as stated in the 2002 mine plan, in operational effectiveness meetings, and by staff members. This project aimed to maximise direct working hours through determination of the main issues hindering performance. External and internal factors were considered and a continuous improvement program (CIP) was developed. The CIP aimed at internal site-based improvement teams to identify and implement solutions for improvement on a day-to-day basis.

Jan 1, 2003

By Steve Kral

The mining industry in Colorado faces the same problems the industry faces throughout the United States and the world — record low commodity prices and increasing regulatory and environmental restrictions that seemed designed to curtail mining activities. Despite those obstacles, the mining industry in Colorado still contributes about $8 billion annually to the state’s economy in the form of base and precious metals, industrial minerals, coal and associated service businesses and jobs. So the 300 attendees at the102nd National Western Mining Conference felt reason-ably positive about the industry in their state. The meeting is the Colorado Mining Association’s annual conference and was held at the Broadmoor Hotel in Colorado Springs in November. The theme was “Mining in the New Millennium — Achievement + Innovation = Survival.” Experts from Colorado’s mining industry and abroad discussed the challenges faced by the mining industry as it enters the new millennium. They offered insights into how the industry will operate during the early years of the 21st century and how it will survive low prices and increased regulatory restrictions.

Jan 1, 2000

Radioisotope x-ray methods for the on-stream determination of copper, lead, and zinc in mineral product slurries were developed, and were successfully tested at the plant of Cobar Mines Pty. Ltd.The tests were made in three stages. Measurements to determine the precision of analysis were made initially on briquettes of the mineral products. The effect of slurry solids content variations was then determined by measurements on the mineral products in a recirculating slurry loop. The radioisotope analyser was finally tested in a series of on-stream measurements in the plant.Copper, lead, and zinc in flotation feed and in copper concentrate were determined to a precision ranging between 1·4 and 15 per cent of the mean element concentration in the slurry solids. These precisions are within limits required for plant control purposes at Cobar.

Jan 1, 1971

By M. Fan, M. Mankosa, G. Luttrell

"Column and other non-conventional flotation approaches continue to provide benefits where conventional flotation processes have exhibited limited success. This is particularly evident with respect to flotation of ultrafine and coarse particles. Advancements in air sparging technology have provided the ability to produce finer bubbles than previously possible. The generation of finer bubbles coupled with the froth washing capabilities of a flotation column has demonstrated improvements in ultrafine particle recovery while simultaneously producing a high-grade float product. On the other side of the spectrum, the use of these sparging technologies while applying flotation fundamentals to a fluidized-bed reactor has increased the maximum floatable particle size up to and in excess of 3 mm. Benefits of higher recoveries and reduced reagent consumption have resulted from the use of these technologies. An additional benefit includes a reduction in plant grinding requirements. As such, this paper describes the application of Cavitation-Tube sparger technology and fluidized-bed flotation (HydroFloat). A review of data from industrial and pilot-scale applications is also provided.INTRODUCTIONConventional (mechanical) froth flotation is considered the workhorse of the minerals processing industry. This low-cost process makes it possible to selectively recover minerals by exploiting the difference in surface characteristics (e.g., wettability) of the valuable component and the waste material. Unfortunately, the upper particle size limit for flotation rarely exceeds 0.600 mm, and is typically maintained at less than 0.300 mm for most industrial applications. For many commercial base metal plants, the particle size range for optimum recovery is typically between 0.01 and 0.1 mm (Lynch et al., 1981). This finding is not novel. In fact, the effect of particle size on flotation recovery was studied as early as 1931 by Gaudin et al. who showed that coarse (+0.250 mm) and extremely fine particles (-0.010 mm) are more difficult to recover than particles of an intermediate size. The loss of recovery is due to inherent limitations associated with the flotation process, including bubble-particle adhesion and collision, detachment, buoyancy, and transport."

Jan 1, 2010

By Marco Taipe

Uno de los mayores costos del proceso minero es el de perforación, en tanto emplea aire comprimido. Por tal motivo, la industria minera busca diferentes alternativas para reducir los costos del aire comprimido o eventualmente a través del uso del sistema electro-neumático. Este sistema es de fácil instalación y mantenimiento puesto que se basa en electricidad y agua, reduciendo costos y a su vez mejorando las condiciones de trabajo a través de la versatilidad del presente sistema.

Sep 12, 2011

By Kazimierz Gwizdala

In the paper the method for estimation of settlement of vertically loaded piles in a group is presented. The method is generally based on the hybrid procedure with non-linear solution for single piles and with interaction between them for the low-strain shear modulus. Some attention is paid to the influence of deformation and strength parameters used in calculations. The applied model is verified in the framework of the research programme carried out recently in the Geotechnical Department of Gdansk Technical University. It concerns monitoring and analysing the settlements of the existing structures on piles. A comparison of calculation and measurements results for two tested buildings is presented as an example.

Jan 1, 2002

The object of this paper is to give a description of the new office and changehouse building and equipment at the Zinc Corporation Limited, the office section of which has now been in full use for approximately three years, and the changehouse section for approximately two years. As the expectations of the design have been fully realized, it is thought that this description will be of interest to members and possibly of some use to others faced with similar problems.GENERALIn the centralization of the surface plant around the new main shaft the combined office and changehouse building forms a prominent feature, being located between the shaft and the mill and facing the workshops on the northern side.The scheme for housing all employees in one building was proposed by the Manager, Mr. A. J. Keast, who was familiar with a similar successful structure built at the McIntyre Porcupine Mines Ltd. in Ontario, Canada.The principal features of this building were adopted as a basis for design, and the present layout evolved to suit the particular requirements of this mine.Some of the advantages of the design are:(a) Economy in first cost and space occupied when compared with plants having separate office and changehouse buildings.(b) Easier and more constant supervision of employees and of the plant by the senior staff members.(c) Close contact between officials of all departments.(d) Close covered connection between changehouse and shaft.(e) Avoidance of duplication of ,essential services such as electric power, water, heating plant, sewerage, etc.The Managing Director, Mr. W. S. Robinson, further instructed that the following requirements be adhered to in the new building:(a) Ample accommodation to be provided for office staff and other employees.(b) Special attention to be paid to lighting, both natural and artificial.(c) Working temperatures to be controlled to facilitate comfort and efficiency.(d) The buildings and equipment' to be of a permanent nature with furnishings and fittings of modern design.

Jan 1, 1941

By P. Somasundaran, D. W. Fuerstenau

This article presents the results of an analysis of grinding of 1:1 mixtures of 4x8-mesh quartz and limestone in laboratory ball and rod mills. From these experiments, the amount of energy consumed in grinding each component of the mixture was determined. In the ball mill, limestone consumes slightly more energy than quartz in the initial stages of grinding, but as the grinding proceeds quartz begins to consume a slightly greater fraction of the energy. The postulate that the fraction of energy consumed by any material in a ball mill is proportional to its volume fraction has been shown to be approximately true. On the other hand, in a rod mill energy consumption by quartz and limestone is equal only in the initial stages of grinding, with energy consumption by quartz greatly exceeding that by limestone as rod milling proceeds. Preferential energy consumption in tumbling mills has been discussed in a number of papers. For example, from an analysis of the kinetics of comminu- tion in ball mills, Arbiter and Bhrany' obtained rate equations based on the postulate that only coarse particles are ground, indicating that fine particles are protected from the action of the balls by coarser particles. In rod mills this protective action is much more pronounced than in ball mills. Recent studies on the rod milling of limestone-quartz mixtures have shown that this protective action causes the mineral with the lowest grindability (quartz in this instance) to consume the greater fraction of energy. 2 However, in the ball milling of mixtures it has been postulated that the consumption of energy by one of the constituents is determined by its volume fraction within the mill. 3 Possibly this hypothesis may be a simplification of the ball milling of mixtures since the protective action suggested by Arbiter and Bhrany may result in some preferential energy consumption by one of the constituents of a mixture. The objective of this study has been to determine preferential energy consumption in laboratory ball and rod mills by analyzing size distributions of each material in the products obtained from grinding 1:l mixtures of quartz and limestone. MATERIALS AND METHOD The procedure for carrying out the tests on wet grinding quartz-limestone mixtures has already been described.'r3 In the present investigation, 1:l mix-

Jan 1, 1963

By Lucien Eaton

THE use of filling in mines is less common in the United States than it is in Europe, where in some places it is required by law. In most cases the filling is placed by hand, and the material used for this purpose is the waste from development and that sorted from the ore in the stopes. When these sources provide an insufficient supply, additional rock must be quarried on surface or mined underground, or some other material :st be used. In different parts of the world sand, clay, gravel, culm, nulated slag, mill tailings, and even ashes, have been used as filling material in place of or in conjunction with rock. Of all the materials used for filling the best is probably clean sand. Gravel, finely crushed rock, granulated slag and coarse mill tailings are almost as good, and the methods used for placing and confining sand will apply equally well to any of these. The advantages of sand are its comparatively slight compressibility and the ease, economy and convenience with which it may be placed. On account of the voids, which necessarily occur in fills made of coarse waste, such fills will compress 10 to 25 per cent before they develop their full strength, whereas clean sand seldom compresses more than 5 per cent. Sand is especially desirable when practically complete filling is required, and sand derived from mill tailings, especially when not thoroughly cleaned, has been remarkably effective in sealing off and extinguishing mine fires. When natural sand is available on surface, or when it can be obtained from the mill tailings or tailings dump, the cost of using this material for fill will probably be considerably less than that of rock. In this paper it is not proposed to discuss all methods of filling, butt to describe some of the methods used for placing sand fill and to make a brief comparison of their merits.

Jan 1, 1932

Local conditions at Hatches Creek are described, together with the mineralogy, mining and treatment of tungsten ores, with particular reference to procedures adopted by Pimer Mines, N.L.The Hatches Creek tungsten field covers an area of about 20 square miles in: Central Australia; 285 miles' N.E. of Alice Springs. Access is by rail to Alice Springs, then by 200 miles of bitumen highway to Barlo Creek and 8,5, miles of bush track to the field. Passengers can also reach the mines by... A semi-desert climate prevails Rain; generally in the form of thunderstorms falls in the summer months: December to March. Average annual rainfall is approximately 15 inches but there is great variation from year to year, occasional droughts being followed by torrential downpours. Vegetation is sparse except in the wide creek beds. Surface water occurs in rock holes some of which, spaced miles apart, carry permanent water...

Jan 1, 1955

By T. Gupta, T. Ghosh

Rare earth elements (REEs) and their compounds are essential in a multitude of mundane and sophisticated applications such as renewable energy technologies, catalysts, medicine, and defense applications. The global supply deficit could be attributed to the destabilization of REE market that has, as a result, incentivized indigenous production of REEs. Cost-effective and environmentally benign opportunities are being explored for the production of REEs from non-conventional mineral sources including coal and coal by-products to stabilize the supply chain. Coal from Healy coal mine and Wishbone Hill deposits in Alaska have been quantified for REEs and were found to possess elevated total REE concentrations as compared to world average levels (60– 70 ppm). The objective of the study was to concentrate the REEs in the froth phase by froth-flotation of the fine size fraction (< 75 μm). A Box-Behnken design of experiment was employed to ascertain the main and interaction effects of operational parameters on response variable by analyzing 3D response surfaces. Experiments were carried out to maximize REE recovery and concentration by modeling and optimization of three operating variables (frother dosage, pulp density (% solids), and collector dosage). Based on the results, the optimum flotation conditions for maximum recovery at an elevated concentration of REEs in the froth fraction was obtained at 4.2% solids and 32.7 ppm of frother dosage for Healy sample and 10% solids and 37.9 ppm of frother dosage for Wishbone Hill coal sample. The quadratic relationship between the input and response variable was found to be independent of collector dosage suggesting good surface hydrophobicity and floatability of the two coal samples.

ONE of the phases of mining wide ore-bodies, such as are found in Broken Hill, is the laying-out and design of the sill floor gangway timber, When, in the above operation, a detail has to be repeated frequently, it is desirable in the interests of efficiency that that detail should be standardized as far as possible. Before arriving at a standard design e.g., a crosscut layout-it would seem necessary to compare its strength with some other unit of timber and see that the general design is at least as strong as the unit that has been taken for comparative purposes, In these notes no attempt is made to calculate the stresses to which timber underground is subjected, but merely to draw a comparison between the relative strengths of the various cross sections of timber in common use underground.It has been assumed for the purposes of comparison that the milling exerts pressure in a vertical plane only, and is uniformly distributed over any area. A beam supported at both ends, and with a uniformly distributed load, has the maximum bending moment at a point midway between the points of support, and equals- WL2 8 where W = load per unit length. L = distance between points of support.The bending moment also equals M-, where y M = modulus of rupture of the material in question. I = moment of inertia of the section of the beam about a given axis.Y = distance of extreme fibre from that axis. WL2. I The formula -8- = MY- only holds good until the elastic limit...

Jan 1, 1923

By A J. H Newell

The background and the basis for conducting a Technical Due Diligence are discussed as well as the source information, typical studies and potential limitations. Typical short comings including ‘show-stoppers’ are presented for the metallurgical area, with examples. Issues found in other areas such as geology, mining, infrastructure and financial evaluations are briefly reviewed, highlighting the input and interaction required by metallurgists with these disciplines. A checklist is provided as a guide to maximise the success of a Due Diligence as well as a check on the quality of a Feasibility Study.CITATION:Newell, A J H, 2015. Fatal flaws in technical due diligences, in Proceedings MetPlant 2015, pp 61–77 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By Michael McNinch, LaTasha R. Swanson, Jennica L. Bellanca, Justin Helton

Accident data indicates that mobile haulage poses a significant pinning, crushing, and striking risk. Proximity detection systems (PDSs) have the potential to protect mineworkers from these risks. However, unintended consequences of mobile PDSs can undermine the safety benefit they provide. Soliciting iterative user input can improve the design process. Users help provide a critical understanding of how mobile PDSs may hinder normal operation and endanger mineworkers. Researchers explored users’ perspectives by conducting interviews with mineworkers from seven mines that have installed mobile PDSs on some of their haulage equipment. Mineworkers reported that mobile PDSs affect loading, tramming, section setup, maintenance, and general work on the section. Mineworkers discussed the operational effects and increased burden, exposure, and risk. Mineworkers also suggested that improved task compatibility, training, logistics, and PDS performance might help address some of these identified issues. This paper also gives additional insights into mobile PDS design and implementation.

By Michael McNinch, LaTasha R. Swanson, Jennica L. Bellanca, Justin Helton

Accident data indicates that mobile haulage poses a significant pinning, crushing, and striking risk. Proximity detection systems (PDSs) have the potential to protect mineworkers from these risks. However, unintended consequences of mobile PDSs can undermine the safety benefit they provide. Soliciting iterative user input can improve the design process. Users help provide a critical understanding of how mobile PDSs may hinder normal operation and endanger mineworkers. Researchers explored users’ perspectives by conducting interviews with mineworkers from seven mines that have installed mobile PDSs on some of their haulage equipment. Mineworkers reported that mobile PDSs affect loading, tramming, section setup, maintenance, and general work on the section. Mineworkers discussed the operational effects and increased burden, exposure, and risk. Mineworkers also suggested that improved task compatibility, training, logistics, and PDS performance might help address some of these identified issues. This paper also gives additional insights into mobile PDS design and implementation.