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In the last two years the Commission for the Environment has received four Environmental Impact Reports (EIR) for Audit and has been or is involved with at least four environmental impact assessments (EIA) related to mining. The EIRs have included Weavers Coal Mine, the Monowai-Maratoto mining proposal, the Martha Hill mine and the Wainui Road Mill. The EIAs are related mainly to coal fields in the Waikato but also included a further EIA on Martha Hill.

Jan 1, 1986

By Charles Kocsis

Over the last few years a multi-faceted feasibility study has been evaluating the introduction of hydrogen fuel cell powered equipment into underground mines to replaced diesel engine powered equipment. The analysis has shown that under normal operating conditions fuel cells could at the very least be an environmental and health benefit by eliminating combustion engines and their unwanted by-products. However, they could also generate significant reductions in the amount of ventilation a mine needs to supply when compared to dieselized operations; this would further decrease a mine?s energy consumption, its associated greenhouse gas impact and also reduce a mine?s significant ventilation associated costs. Fuel cell powered equipment also has the advantage of lower noise and heat production compared to their equivalent diesel powered counterpart. The degree to which fuel cells can generate ventilation benefits in underground mines depends upon a number of operational parameters and mine specific qualifiers such as current ventilation control or management, mine depth, inherent dust conditions and minimum velocity requirements. However another major consideration in the introduction of fuel cells in underground mines will be the safety requirements associated with diluting and removing the potentially explosive hydrogen in the event of a gas leak. In outside surface applications, it is possible to use dispersion, buoyancy, time, and lack of ignition sources as mitigating factors in deriving a low risk of an explosion. However, in underground operations these factors change, dispersion and buoyancy are limited; time may not be available and in non-coal mines ignition sources are not typically controlled. When a hydrogen leak occurs, the availability of sufficient ventilation to dilute and effectively remove the gas will be critical, consequently ventilation may be the prime risk controlling factor. In this paper, the authors evaluate the potential benefits of replacing diesel engines with fuel cells in powered production equipment, discuss the mitigating qualifiers that could limit ventilation savings and evaluate solutions to retain and maintain an additional ventilation capacity in the event of an emergency situation such as a hydrogen leak from the fuel cell stack or its distribution system.

May 1, 2007

By Peter N. Holtham, Geoffrey J. Lyman, The University of Queensland, Matthew S. Brennan, Vijay Subramanian, Rui X. Rong

"The cyclone would have a claim to be the commonest, least understood and most abused piece of mineral processing equipment available for study by researchers. It has certainly generated its fair share of publications – 1,000 in the last 60 years would be a fair estimate. However this remarkable degree of interest and scale of investigation is not reflected in our understanding of how they work; cyclones are still installed inappropriately and run poorly, which suggests that there are still things to learn about this deceptively simple process.In mineral processing there are two broad classes of cyclone: the hydrocyclone, used in classification, thickening and dewatering, and the dense medium cyclone, used for concentration by density. Although rarely studied together, the laws of physics presumably apply equally to both and so it seems that there would be interesting things to learn by considering them as a single class of device. The good news is that in recent years there have been spectacular advances in the computational and measurement tools available to study these devices, including computational fluid dynamics (CFD), tomography, and laser doppler anemometry (LDA), and some good progress has been made in an understanding of the fundamental principles involved.The JKMRC has made many experimental studies of hydrocyclones and DM cyclones, leading to useful empirical models. However some recent CFD and tomographic work, in association with work of other institutions, has thrown important light on the workings of these processes. Progress has also been made in novel designs of cyclone to achieve improved separating efficiency, based on an attack on the subprocesses believed to contribute to inefficient operation. This paper describes the work to date.Modelling of the dense medium and classifying cyclone was conducted using the Fluent computational fluid dynamics code. Three phase simulations of the dense medium application (air/water/medium) showed appropriate medium segregation effects but over-predicted the level of segregation compared to segregation measured by gamma-ray tomography. This is believed to be because the basic Algebraic Slip mixture model in Fluent does not model any back-mixing of the dispersed phase due to turbulence."

Jan 1, 2003

By F. F. von Glehn

There is no doubt that simulated ventilation networks must be adequately verified before they can be extrapolated and used for predictive purposes. There are two general approaches as to how the verification can be established and these are summarised as follows; The first approach is to measure all individual branches with trailing hoses or barometers to get individual pressure drop and flow per branch and then calculate individual resistance factors for input into the software. The simulator is run, checking that the output makes general sense (check some sensitivities if possible). The network is now considered as verified. The pressure drop to be measured is relatively small and thus it is inherent that the measured set of individual K factors will be imprecise no matter how much care is taken in the measurements and the resultant simulations will inherit the same problem. In the second approach, the network is assembled using estimated (Atkinson) K factors (based on physical features of airway, past experience and catalogued typical K factors). Only the main primary flow rates are measured and hence the relative distribution of the primary ventilation in the main airways is determined (probably about 10 off primary air flow measurements). Main critical pressure differentials at main and booster fans and across critical doors are measured (probably about 6 off primary pressure differential measurements need to be made). The simulator is run and the computer model is used to iterate and select an updated suite of K factors so that the flow balances and pressure differentials are correctly simulated (typically only 2 or 3 iterations are all that is needed). The network is now considered as verified. The pressure differences to be measured will be substantial in absolute terms and can be measured with high precision. Also, because only primary flows are measured, these will generally be measured at higher air speed points and hence improved relative accuracy. This leads to more accurate simulation results. This paper examines the advantages and disadvantages of the two approaches. 1 Background

Jan 1, 2009

By Bradley Stoughton

(Cleveland Meeting, October, 1912.) [SECRETARY'S NOTE.-To avoid repetition of foot-notes, references to authorities are made in this paper by means of figures, referring to a numbered list in the appendix.-J. S.] INTRODUCTION. THIS paper gives the results : first, of a research into the somewhat extensive literature of titanium; and second, of a series of original tests upon the effect of titanium on iron castings. New investigations have also been made upon the effect of titanium on steel, but I hope to treat this subject in an independent paper at some later date, and, therefore, will not discuss the experiments in detail here. The combined results of this study, which extended over a period of more than two years, can be briefly summarized as follows: 1. Steel or cast-iron, in which the titanium is properly proportioned, and which has been properly treated, is improved in strength, toughness, and durability against wear, such as, for example, the wear of railroad-rails, of steel and chilled-iron .rolls, car-wheels, etc. 2. These improvements seem to be caused, not so much by the direct effect of titanium on the metal, as by its cleansing influence in removing harmful impurities, such as oxygen and oxides, nitrogen, occluded slags, and perhaps also sulphur. It appears also to reduce segregation, which would contribute to the same end. 3. In order that its effects may be fully realized, the treatment of steel or iron with titanium must be correctly performed. There are a few simple, but essential, details to be observed; if they are neglected, the best results cannot be expected. To illustrate by an example : A series of tests on cast iron

Nov 1, 1912

By James Y. Oldshue

"Very seldom is it possible when contacting a gas with a slurry to measure the dissolved gas concentration in the slurry, and even were it possible, seldom are equilibrium data available with a suitable Henry’s law constant.In general, by assuming a reasonable value for the dissolved gas concentration in the slurry and a corresponding equilibrium gas partial pressure P*, Kga values can be calculated for the pilot plant and scaled up. Then, with the same P* value at various reaction conditions, a mixer can be designed which is quite satisfactory, having a reasonable design factor for full-scale performance.We will take as an example a slurry of a known solids composition and use a continuous 4 tank system. By assuming a percentage saturation of the dissolved gas in the first tank, the dissolved gas concentration can be obtained in the other three tanks. It usually is possible to measure the off-gas composition in each of the 4 tanks. If the top of the tanks is connected in the form of a multi-compartmented horizontal autoclave, then a modified top off-gas composition in each compartment must be used."

Jan 1, 2003

By Richard Hosley, James Daley

Every grey haired member of the explosive’s industry has said at least once, “We have to get some younger blood into our industry, I might want to retire someday.” And many a youngster who loves to see explosions has wondered how to get involved in such an exciting, yet intimidating, industry. While there are many answers to these questions, an internship program is a great answer to both

Jan 1, 2014

By W. J. Mitchell

During the months of April and May 1992, the Phelps Dodge Hidalgo smelter underwent a major turnaround. This was the third such turnaround in the life of the facility which was commissioned in 1976. During the third furnace campaign, the smelter processed 5.2 million tons of concentrate producing 2.6 billion pounds of anode copper over a 7.5 year period. The critical path on the fifty-nine (59) day turnaround schedule was the reconstruction of the Outokumpo flash furnace which integrated some modifications with standard rebuild practices. Modifications included incorporation of horizontal cooling jackets throughout the furnace settler as well as the installation of castable refractory in the reaction and uptake shafts.

Jan 1, 1993

By Wallace E. Pratt

TO SERVE their primary function of balancing supply with demand. crude-oil prices must not only return full cost plus a reasonable earning to the efficient producer but they must also offer an additional reward to stimulate exploration sufficiently to maintain adequate reserves. High prices increase the volume and efficiency of exploration; low prig e- -Idle exploration. Over the last decade average prices for crude oil have been much lower than for the proceeding ten years, and lower even than the average over the life of industry. Under these circumstances no one should be surprised to learn that over this same recent period of discovery of new oil fields has also lagged and fallen below its average level for the previous decade. Crude oil prices have been too ion to support the required activity in wildcatting.

Jan 1, 1941

By Chris A. Fleming

"Interest in the recovery of cyanide from gold and silver plant tailings has heightened in recent years. This interest has been spurred by several factors:Increasingly stringent regulations throughout the gold producing world, governing discharge limits for free and total cyanide to tailings ponds and the environment.The increasing cost of active chemical treatment versus passive (natural degradation) treatment of tailing, to bring them in line with environmental regulations.The worldwide trend to processing of more complex gold ore bodies, which is usually accompanied by higher levels of cyanide consumptions and greater concentrations of cyanide (particularly the copper cyanide complex) in tailings.The growing negative perception of the general public for the gold mining industry, due to several highly publicized cyanide spills in recent years (breaches of tailings dams, accidents involving trucks carrying cyanide to gold plants, etc.).The ability to recover cyanide from gold plant tailings has been known almost as long as the cyanidation process has been practiced, but there has been little incentive to process tailings in this way in the past. With the development of technologies that make it possible to recover and recycle free or complexed cyanide directly from gold plant slurry tailings, which indicates, on paper at least, the potential for significant cost savings compared to cyanide destruction, coupled with the introduction of legislation to seriously limit the discharge of cyanide to the environment in most gold-producing regions of the world, many companies are evaluating the cyanide-recovery alternative."

Jan 1, 2003

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.

By V. T. McLemore

Petrographic analysis of rocks is traditionally performed with optical microscopy using thin sections and point counting. However, this does not provide accurate mineral proportions for sedimentary, volcanic, and soil-like material, because rock fragments, groundmass, and matrix are not identified as specific minerals. In addition, groundmass phases in volcanic rocks can be too fine to identify individually, and making thin sections of intact soil-like material is difficult because much of the material is not well cemented. ModAn is a normative calculation that estimates modes ??by applying Gaussian elimination and multiple linear regression techniques to simultaneous mass balance equations? (Paktunc, 2001) and allows location-specific mineral compositions to be used. One of the features of ModAn that makes it appropriate for this study is that it can model one of several sulfide minerals. Mineral compositions for Questa minerals were determined from electron microprobe analysis and entered into ModAn. Then by combining and normalizing results, bulk quantitative mineralogy can be determined using ModAn, petrographic observations, electron microprobe analysis, clay mineral analysis, and the whole-rock chemistry of the sample.

Jan 1, 2009

By Roger A. Bullivant

The introduction of this size and type of piling rig is intended to address a multipurpose foundation activity. The 8000 denotes the size of equipment that is attached to the mast, namely 8000 Kg. Larger equipment can be carried subject to adjustment of rig geometry. The 8000 series rig will easily accept hydraulic piling hammers and CFA equipment, but for the purpose of this discussion it will be equipped with an auxiliary power pack that is matched to twin vibrators. The design of the siamesed vibrators allows long tube equipment or piles to be driven with a short mast configuration that provides a lower overturning risk. It is easily adapted within minutes to carry out other foundation requirements that are required on the same contract. The piling and ground consolidation activities that can be undertaken by the 800 series machine are:-

Jan 1, 1995

New ZealandÆs share of global greenhouse gas emissions, at about one fifth of one per cent, is very small. But the profile of those emissions is unique among OECD countries; more than half come from methane and nitrous oxide associated with livestock agriculture. Consequently, fulfilling its obligations under the Kyoto Protocol is potentially quite onerous for New Zealand.In this paper we use a single region, static general equilibrium model to assess the implications for New Zealand of various climate change policy options. The energy and agriculture sectors are modeled in a detailed manner to enable realistic simulations to be carried out.Choosing an optimal set of policies is made more difficult by the fact that New Zealand relies heavily on emission intensive sectors for much of its export earnings. For example, one emission intensive sector alone, dairy, accounts for over 20 per cent of all merchandise exports. Avoiding carbon leakage is therefore an important consideration in selecting appropriate greenhouse policies.Our analysis shows the degree of sectoral adjustment required is substantial. In addition, the total costs depend on the uncertain level of variables such as the global carbon price and the level of afforestation activities in New Zealand, ie the rate of new forest planting.

Jan 1, 2002

By Derek J. Cyr

Climate has an immense impact on the properties of Athabasca oil sands and the ease or difficulty with which it is excavated and extracted. During the winter months, exposed oil sands surfaces freeze. When hydraulic and electric shovels used in the various operations in the Fort McMurray area excavate the benches, large frozen lumps are created. These lumps are either destined for a lump dump where increased costs are incurred due to rehandle, or they are sent to the primary crushers where they can cause significant downtimes by jamming the crusher. The crusher down time can sometimes be in the order of hours of lost production. Studies on data from two consecutive winters at Syncrude Canada?s North Mine show a high correlation between climate and the generation of frozen oil sands lumps. Temperature, ground cover, traffic, bench exposure time, oil sands grade and moisture content all contribute to this problem. A 1D frost penetration model was used to predict the depth of frost expected in oil sands and the corresponding likelihood of frozen oil sands lumps. To combat the challenge of frozen lump generation, a number of proactive and reactive measures can be taken: artificial snow, shallow ponds, scheduling, blasting or ripping.

May 1, 2004

By G. Donald Emigh

WESTERN phosphate resources which lie in Ida- ho, Montana, Utah, and Wyoming, have seen great expansion of activity in recent years. Growth has been two-pronged: expansion in fertilizer use, and since 1949, into the elemental phosphorous industry. Elemental phosphorous, produced in the electric furnace, goes largely into chemical making. Phosphate ore was first recognized in the West about 1889. Production started in 1906, and for many years consisted of underground operations by small companies operating sporadically. In 1920 Anaconda Copper Mining Co. opened the underground Conda mine near Soda Springs in southeastern Idaho, and has maintained and increased its operations since then. About 1930 Montana Phosphate Products Co. began underground mining in Montana and has remained a steady producer. In 1945 San Francisco Chemical Co., one of the oldest companies in the western field, initiated strip mining at the Waterloo mine near Montpelier, Idaho, and later at Leefe mine near Sage Junction, Wyo. In1946 J. R. Simplot Co. began open pit mining at Gay mine near Fort Hall, Idaho. In 1950 Victor Chemical Works began underground development work in the area of Maiden Rock, south of Butte, Mont.: and has since mined there. Monsanto Chemical Co. began open pit mining near Soda Springs, Idaho, in 1951.

Jan 11, 1954

By Jürgen F. Brune, Alex C. Smith, William D. Monaghan

One of the predominant causes of fires in underground coal mines is flame cutting and welding. These fires can lead to major events such as the explosion that occurred on January 22, 2003 in an airshaft being constructed at the McElroy mine. Six contractors were inside the shaft at the time of the explosion and the explosion fatally injured three and seriously injured three [MSHA 2003]. Understanding the root causes of these fires and explosions will help prevent these types of events from occurring in the future. Fires and explosions require fuel, oxygen and an ignition source (heat). These three items are referred to as a fire triangle. The control of these three items in flame cutting and welding operations is required to prevent fires and or explosions. United States Department of Labor, Mine Safety and Health Administration (MSHA) Reports of Investigation (ROI), MSHA Mine Accident, Injury, and Illness Reports, and the MSHA Mining Industry Accident, Injuries Employment, and Production Data Base were analyzed and interviews and observations with mine workers and welders were conducted to determine the root causes of coal mine fires and explosions caused by flame cutting and welding operations. This paper will discuss the root causes and potential means to reduce the number of fires and resulting fatalities and injuries caused by or due to flame cutting and welding.

Research on Universal Depressant of Talc and Serpentine

Sep 13, 2010

By G. R. Fitterer, M. B. Royer

The application of manganese in iron and steel metallurgy is very inter¬ esting historically. In general, ancient- irons and steels contained virtu¬ ally no manganese, probably because the available iron ores contained■only small amounts of the manganese oxides. Occasionally, samples of ancient irons were found to have appreciable amounts of manganese, but their presence is considered accidental and dependent upon the ore available to craftsmen of that time. Two specimens of iron (139;— made in 500 A.D. contained .negligible quantities of manganese. A sample of steel which constituted the base of .the Khan Baba pillar in India was probably processed in 12p B. C. by the1 cementa¬ tion of wrought iron. This material; contained 0.02 percent manganese and 0.70 percent carbon (20) . One Damascus-steel sword forged some time between 11'60 ' and l400 A. D. was found to contain 0.1^-i percent manganese and 0.j6l percent carbon. The manganese content of this bla.de was much higher than that of any other material of this type which has been analysed. In every other instance the manganese content was below 0.02 percent. A cast steel manufactured by the East India. Co. in India in the early nineteenth century, under the name of Wootz steel, contained rather appreciable amounts of manganese. This material was made by melting and refining fairly high-manganese pig iron prepared from high-manganese ore. Heath (106), who was working at the Co. plant between 1S20 and 1S40, was convinced that the manganese content of the steel was the determining fa,ctor in its high quality. He learned of certain difficulties English steel manufacturers were having in making even fair-grade steel, and analyses of the material indicated low manganese contents. This convinced him that.if the use of manganese could be introduced in England its steel would be greatly benefited. In consequence, he moved to England and soon was producing certain grades of ferromanganese for use with the crucible process. He recommended addition of this metallic material to the ingot mold just before pouring. It was soon found that inferior brands of steel containing only traces of manganese could be greatly improved by such additions. All metallurgists of that time became convinced

May 1, 1934

By Atsushi Shibayama, Toyohisa Fujita, Luo Lin, Toshio Miyazaki

A novel process is developed in this study for separation of tungsten and vanadium from a leach solution of tungsten alloy scraps. Specifically, a magnesium salt combined ammonium solution is employed to precipitate vanadium and impurities in the purification of the leach solution. This separates vanadium from tungsten by rejecting tungsten in aqueous solution. Finally, tungsten is recovered as the form of ammonium para-tungstate (APT). Vanadium is recovered as the form of ammonium meta-vanadate(AMV).

Jan 1, 2003