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By Taylor R. G

This paper reports a biogeochemical study of the Siberia lode of the Herberton tin field. Soil near the orebody contained high levels of Fe, Cu, Pb, Sn, As, Mld Mn. Polycarpaea spirostylis and Indigofera dominii were associated with these high levels but several other species apparently could not tolerate them. The potential of these species as indicator plants is discussed.

Jan 1, 1975

By Yoginder P. Chugh

This study has appraised available deeper soil loosening equipment in the 1-4 ft. depth range, in the U.S. and abroad which has potential for Illinois prime farm-land reclamation. The appraisal was based on written and/or oral contacts with equipment manufacturers, reclamation experts, and visiting with selected equipment manufacturers. The results indicate that several manufacturers in the U.S., West Germany, and England market static and vibratory deeper soil loosening equipment which may have potential for application in Illinois. The pertinent information concerning each equipment with potential is presented in this report.

Jan 1, 1983

By P. A. Neill, O&apos

The caisson foundation for Vent Building No. 6, at the southern landfall of Boston's Third Harbor Tunnel, was installed inside an unbraced concrete cofferdam 250 feet in diameter and about 70 feet deep. As a spectacular engineering feat, the cofferdam itself certainly ranks first. However, the foundation work within was no routine caisson job and made its own contribution to the state of the art. Comprised of 5 ft. diameter caissons socketed 10 to 16 feet in sound rock, it posed serious challenges in logistics, space limitations and time, requiring development of unique, purpose-made equipment. The unexpected discovery of significant depths of shattered rock overlying acceptable sound rock, along with other surprises of lesser import, compounded the problems. How these challenges were planned for, met and overcome is the subject of this paper.

Jan 1, 1994

By J. A. Finch, Zhenghe Xu, Z. A. Zhou

Whether the microscopic bubbles generated by the high energy dissipation and high feed-slurry velocities in new flotation cells are stable in solution and what roles they play in particle collection are of great interest for the flotation of fines. Experimental work has shown that, with fast flow of liquid through an orifice, stable microscopic bubbles can form in flotation systems by hydrodynamic cavitation in the absence of gas supersaturation. The minimum flow rate at which bubble formation is initiated varies from 8 to 15 m/s, depending on the design of the cavitation tube, which is within the range of feed slurry velocities of some newly developed cells. Feed aeration enhances the formation of micro-bubbles by hydrodynamic cavitation. The study suggests that the fast flotation kinetics of some new cells may be attributed in some degree to the formation of microscopic bubbles

Jun 21, 1905

By Paul Richardson

This paper will review several projects completed during the period from 1976 through 1984 which have been carried out utilizing big hole drilling concepts. The projects discussed will be from various industries to demonstrate the extent that big hole drilling methods are being used along with the current state of development. There will be a discussion of projects planned for the future where big hole drilling methods are the only technology being considered. Also included in the discussions will be an overview of the most recently completed heavy oil recovery project. During the next decade, big hole drilling methods will be used more and more in all industries where underground access is required. The safety, speed and economics associated with shaft sinking using drilling methods are becoming more and more recognized and the technology is rapidly becoming an accepted shaft sinking method.

Jan 1, 1985

By Remo Grandori, Manfred Jaeger, Fabrizio Antonini, Luis Vigl

The EVINOS-MORNOS tunnel project with its 30 km of length is one of the longest hydraulic tunnel in the world realised with TBM method. The adverse geological conditions, the high cover and the short construction schedule were a great challenge for the successful construction of this tunnel. The paper will describe: the criteria adopted for the tunnel design, the selection of the construction methods and equipment, the productions of the 4 TBMs adopted and the comparison of the behaviour of the different type of TBMs in the various rock conditions, including special conditions, the characteristics of the adopted in situ and precast linings, a comparison between the foreseen and actual construction schedules, the contractual implications of realising a tunnel in such a severe and complex conditions.

Jan 1, 1995

By R. L. Levens

Researchers at the U. S. Bureau of Mines conducted investigations to evaluate the potential for ground water contamination by mine waste used as backfill. Samples of cemented waste backfill and water discharging from drillholes and seeps were collected to use in chemical analyses and laboratory tests to determine the physical and chemical factors that control release of heavy metals to ground water. Greater water retention by cemented backfill (as compared to uncemented sandfill) reduces the surface area exposed to oxidation, which in turn reduces the amount of acid produced. The acid is neutralized by the cement and minerals contained in the backfill. The grain-size distribution of tailings used for backfill affects the structural integrity of cemented backfill under attack by acidic water; breakdown of the backfill structure releases neutralizing materials faster. Backfilled stopes in rock with low hydraulic conductivities will constitute preferential flow paths after mine flooding; however, the rate of flow through backfill will be much slower than when the stope is partially saturated during mine operation. Considering all factors, acid generation and release of metal ions from cemented backfill should be less than in uncemented sandfill.

Jan 1, 2010

The Direct and Indirect Effects of the Reagent Suite on Froth Stability in Laboratory Scale Batch Flotation Tests

Sep 13, 2010

By Ronald M. Lewis

Quadratic functions, Q(hkl), are given to six places in increments of 0.01° for 2? from 00 to 90° for FeKa and from 25° to 180° for FeKa1. The wavelengths used for Fe in the computation are those agreed upon by the Editorial Commission of the International Tables for X-ray Crystallography (1950): FeKa1 1.93597 A.; Feka2 1.93991 A. INTRODUCTION At the Federal Bureau of Mines laboratory, Norris, Tenn. X-ray diffraction crystallography using tubes with iron targets revealed a need for a handy reference for the quadratic functions of iron radiation. The tables presented here were prepared to satisfy that need. The quadratic form Q(hkl) may be expressed in terms of the Bragg diffraction angle 2? and of the wavelength ? as

Jan 1, 1961

By N H. Jansen, H L. Bridgwater

Field portable X-ray fluorescence (XRF) and near infrared (NIR) instruments are proven technologies in the minerals industry. The in-field results of these instruments can add value early in the project life, leading to cost-effective decision-making compared to their equivalent laboratory based techniques. However, in order to add value to a project, it is crucial that the instruments are employed correctly.Orientation studies should be carried out prior to initiating a sampling program to achieve the highest level of quality assurance and control for the results. Hence, an appropriate sampling workflow begins with considering what outcomes are required, including level of precision, accuracy, reliability for elements and minerals of interest, and sampling errors. The workflows proposed include soil sampling and reverse circulation and diamond drilling sampling techniques, and laboratory based techniques. They are practical and flexible workflows using available portable XRF and NIR technologies that can be applied to current sampling and drilling methods.The combined technologies have the ability to create large, integrated geochemical and mineralogical data sets that can provide cost savings for every stage of the mining chain from exploration to prefeasibility, mineral processing and environmental remediation.CITATION:Jansen, N H and Bridgwater, H L, 2017. Proposed workflows for portable X-ray fluorescence and near infrared instruments for soil and drill hole sampling, in Proceedings Eighth World Conference on Sampling and Blending , pp 219–228 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

The corrosion of aluminosilicate refractories by soda from three different sources has been studied by microscopic methods. Sodium sulphate from oil ash, sodium chloride used in glazing structural clay products, and sodium borate from borax-impregnated wood ash have fundamentally the same effect on the refractories. The soda is the chief medium of reaction and fluxing, the sulphur, chlorine, and boron being volatized as sulphuric, hydrochloric, and boric acids.INTRODUCTIONBecause of their strong fluxing action, alkalis are one of the main causes of corrosion and slagging of refractories.The action of potash and soda on refractories follows somewhat similar lines, although it is common for one alkali to be greatly in excess of the other. The course of the reaction in a number of cases of alkali attack has been studied by microscopic and chemical methods. For example, the action of potash on blast furnace refractories was studied by Kraner (1942) and Rigby and Richardson (1947), who described the occurrence of various potassium aluminium silicates. Its action on cement kiln refractories was described by Brisbane, Segnit, and Weymouth (1957). The action of soda on glass tank refractories has been studied by many people, for example Bisby (1956) and Resch (1954). Clews, Hugill, and Green (1940) made a microscopic examination of the attack by soda on silica bricks from a gas retort.Some recent cases of corrosion of aluminosilicate refractories which were brought to the attention of the Division of Building Research, C.S.I.R.O., illustrate phenomena which occur under conditions different from those...

Jan 1, 1964

By G. R. Robinson

Aggregate resources consist of sand and gravel, and crushed stone. They are large-tonnage, bulk-minable mineral commodities that are used in construction and industrial activities (Tepordei, 1999, 2001).Rates of aggregate production, use and mine permit approval in the mid-Atlantic region differ by population density. These rates are influenced by economic and human factors, such as demand, costs, land availability and community opposition. In some areas, the local availability of aggregate is limited. This is due to the lack of suitable local source materials for aggregate, the loss of potential high-quality aggregate resource production sites by preemptive land development and restrictive zoning (resource sterilization), and the difficulty of developing and permitting production sites for aggregate.

Jan 1, 2004

By D Craw, D Wilson, D Chappell

Gold is extracted by cyanidation of a sulphide-rich concentrate at Macraes mine, and after cyanidation, the concentrate is discharged to tailings impoundments. The concentrate tailings were discharged to a dedicated concentrate impoundment from 1989 to 1993, afterwhich they were blended with the flotation tailings. Since mid-1998, concentrate tailings have been redirected to the dedicated concentrate impoundment. The concentrate tailings contain up to 1 ppm gold, and will be reprocessed in the future. However, it is a regulatory requirement that a contingency plan be in place to rehabilitate the concentrate tailings should the mine operation cease for any reason. Initial predictions suggested that the sulphide-rich tailings would oxidise and acidify, creating a potential long term environmental problem. Investigations of the state of the tailings after 4 years show that these predictions were overly conservative. Only minor oxidation has occurred in the upper 2 metres of the tailings where the pH has locally dropped from 10 (discharge condition) to between 7 and 8. Below 2 metres, the tailings are essentially unchanged from their deposition state. The low rate of change in the tailings is due to their very low permeability which in turn is a consequence of the fine grain size (ca. 15 ¦m). Dewatering is extremely slow, and incursion of oxygenated water is negligible. Calculations suggest that water movement over 30 m will take at least 100 years and possibly 1000 years. The contingency plan is to capitalise on the very low permeability and keep the tailings from drying with a semipermeable cap. A layer of limestone will be added to the top of the tailings, beneath the cap, to enhance alkalinity of any percolating water. If acidification does occur, contrary to expectations, any acid produced will be neutralised by underlying calcite-bearing schist, schist in the concentrate impoundment wall, and the flotation tailings immediately downstream. In addition, dilution by alkaline ground and surface waters would further ameliorate any acidic discharge.

Jan 1, 1998

By E. W. J. Thornton

During the past six or seven years extensive research has been performed on ore samples procured at the Bruns1,vick Tin Mines which is located in the south-west corner of New Brunswi.ck. This property was originally staked by Mount Pleasant Mines and they did considerable metallurgical and geological work on a small copper, zinc and tin deposit. In 1969, the property was obtained by the Sullivan Mining Group and after much geological and diamond drilling work, an entirely separate ore body \Vas located two miles south of the previous workings. The major economic metals in this ore zone are tungsten, bismuth and molybdenite, but many other metals exist as well. As the ore contains a host of different mineral species, it can be seen that considerable time WRS required to develop a practical flow sheet.

Jan 1, 1977

Fire-clay blocks lining the combustion chambers of zinc concentrate flash-roasting, furnaces operating at 1,000-1,200° C. have suffered moderately rapid deterioration due to slagging. The attack is accentuated by high temperatures, and is probably caused by lead oxide volatilized from the roasted concentrate.Resistance of refractories to attack increased with increasing alumina content from 30 to 45 per. cent but at 90 per cent alumina spalling was troublesome. Magnesite bricks were'subject to some spalling, but some types may lie satisfactory. Chrome and chrome-magnesite bricks spalled seriously.Material thought to be suitable for use as a monolithic lining slagged badly and an alternative may be tested.INTRODUCTIONThe Electrolytic Zinc Company of Australasia Ltd. uses two multi-hearth furnaces and four flash or suspension roasting furnaces for the roasting .of zinc concentrates at its Risdon Works. The hearth roasting plant has been described previously by Forster (1949).A brief descriptioI1 of the first three flash roasters was given by Gordon and Forster (1955). A fourth flash roasting furnace began operation early in 1957. This furnace is somewhat larger than the earlier furnaces, and the designed capacity is also higher, auxiliary equipment being altered to suit. An important structural difference between the older furnaces and the fourth flash roaster is that the walls of the combustion chamber of the new furnace are lined with high alumina fire-bricks instead of fire-clay blocks. Thischange was made because the fire-clay blocks in the older flash roasters had shown s-evere wastage due to slagging by lead derived from the concentrate.

Jan 1, 1959

By A. J. Monhemius

"The paper reviews the history of modern iron control processes in hydrometallurgy. Particular attention is paid to the processes developed in the 1960s by the electrolytic zinc industry for the removal of iron from zinc sulphate leach liquors - namely the Jarosite, Goethite and Hematite processes. Problems faced by the industry in the safe disposal of the iron residues produced by these processes are discussed. The lessons learnt over the past half century by the zinc industry are projected on to the current efforts to develop hydrometallurgical processes for the treatment of copper sulphide concentrates. It is argued that any attempt to create a “hydrometallurgical copper smelter” is doomed to ultimate failure, unless and until methods are developed that can recover iron from solution in a form that can be directly utilised by the steel or pigment industries.INTRODUCTIONYou suddenly realise that age is catching up with you and that technology is moving on apace when you are asked to talk about the history of a process or a technology that you’ve grown up with. Such was my reaction when, out of the blue, I received an email last year from the chairman of the CIM’s Historical Metallurgy Committee, asking me if I would give a talk on the early developments of iron control in hydrometallurgy. Once I’d got over the initial shock of realising that I had now become living history, I was of course flattered that the invitation was to give a talk at the prestigious IMPC, a conference series that has been going for as long as I have been in the business. That this particular IMPC was to include the 4th Symposium on Iron Control in Hydrometallurgy, made the invitation even more appealing and appropriate, because I was the co-chairman of the First Symposium on Iron Control, together with my old friend, John Dutrizac (known by many as Dr Jarosite), which was held 30 years ago in Toronto.first became involved with iron at the very start of my career in hydrometallurgy – the research topic for my Masters degree thesis at UBC, back in the mid 1960s, was “Reductive leaching of Goethite with SO2”. My thesis supervisor was the late Professor Ian Warren, who himself was a protégé of Professor Frank Forward, one of the founding fathers of modern hydrometallurgy. Little did I realise at that time, now 50 years ago, that the problem of iron and how to deal with it in hydrometallurgical processes would be a theme that followed me throughout much of my 40-year career in academia."

Jan 1, 2016

In this paper, geostatistical techniques are applied to forecast the annual copper price in the short and medium terms (from one to five years ahead). These techniques allow the incorporation of monthly and multivariate information in the analysis and provide more accurate results than traditional approaches, especially as far as the one-year forecast is concerned. A second advantage of geostatistics stems from its ability to assess the uncertainty associated with the unknown future prices, thanks to estimation variances or confidence intervals, depending on the technique used. Such an assessment has a crucial importance in decision-making, from both macroeconomic and microeconomic points of view

Sep 1, 2004

By Tjaar A. Louw, Albert P. Van Niekerk, Johannes J. Louw, Attie J. Goosen

Unlike molecular high explosives, commercial explosives based on ammonium nitrate do not detonate ideally according to the theoretical model for steady state, one-dimensional detonation. One of the reasons for this deviation from ideal detonation is the slower chemical reaction, due to less intimate contact between the oxidiser and fuel components. It is well known that the inclusion of gas pockets, such as microballoons, in the formulation of ammonium nitrate based emulsions and watergels enhances the performance of these explosives. Various different interpretations of the “hot spot” theory have been proposed to explain this phenomenon.

Jan 1, 1997

By Niels Kofoed

Upon completion of the 6,200 m (20,340 lineal ft; lft) North Tunnel drive for the Portland East Side Combined Sewer Overflow (CSO) Tunnel project in Portland, OR, the slurry tunnel boring machine (TBM) had to be returned from the Port Center shaft at Swan Island to the Opera shaft at the main mining site for the 2,700 m (8,860 lft) South Tunnel drive. At the Port Center shaft, the main 513-t (565-st) TBM and TBM tailshield were hoisted out of the shaft in two pieces using four 200-t (220-st) strand jacks mounted on a 635-t (700-st) hydraulic boom gantry system supported by Emmert International?s custom gantry tracks designed to span the shaft. After lifting the TBM components out of the shaft, the gantry system loaded the TBM components onto two Goldhofer platform trailers, which then transported the TBM and tailshield to a barge using a roll-on/roll-off method.

Jan 1, 2011

Principal component analysis of the variation of Cu, Ni, Zn, Pb, Mn, and Cr in a control group of 96 samples of surface ironstone from the Yilgarn Block, Western Australia, was used to derive a simple graphical method, based on only Cu, Ni, and Cr, for discriminating between massive nickel gossans and other ironstones.When the graph was tested by plotting 400 control samples, it failed to correctly classify only nine out of 176 gossans and 11 out of 224 other ironstones.

Jan 1, 1974