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By R G. Barker

This paper reviews the annual status of the New Zealand mining industry (metallic minerals and coal) including key aspects such as mineral production, mineral exploration expenditure, commodity price trends, key industry players, market activity and other significant commercial factors.   Strong commodity prices during 2006 have been underpinned by a number of key factors including US dollar weakness and emerging market demand, particularly from countries such as China and India. In real terms commodity prices have recovered significantly since 2002 and are currently at 20-year highs.   New Zealand exploration spending on metallic minerals (predominantly gold) is at a 15 year high driven by rising global commodity prices. New Zealand gold production in 2006 was about 340,000 oz and is expected to grow in 2007 as new mines at Frasers and Globe-Progress (Oceania Gold) and Favona (Newmont) come on stream. Gold production broadly lags 10 years behind exploration spending and exploration activity over the last five years remains well below that seen in the early 1980Æs. Expenditure on coal exploration shows a similar trend with strong growth from a low base over the last five years, reaching over $11 M in 2006. Total coal production in 2006 was 5.9 Mt, an increase of 10% on 2005 with imports from Indonesia adding a further $1.1 Mt.   Newmont and Oceana Gold are by far the largest public gold mining companies operating in New Zealand, although only Oceana Gold maintains a presence on the local stock exchange. Other metals explorers with New Zealand projects include a range of public-listed Juniors (market capitalisation less than NZ$50m) domiciled largely in New Zealand, Australia and/or Canada. Capital-raising on public markets directed towards New Zealand exploration is estimated at around NZ$12 M for 2006, the bulk of this coming via Glass EarthÆs NZ$10 M IPO on the NZAX in October.   The New Zealand Coal sector is dominated by the state-owned enterprise Solid Energy with around 80% market share by production. Other domestic coal competition remains limited, and includes the L&M Group, Pike River Coal, Eastern Corporation, and New Vale (acquired by Solid Energy in 2007). Pricing parity comes mainly from imported coal and global thermal coal prices have remained strong during 2006 at around US$45-55/t, driven by continued expansion in Chinese demand. Coking coal prices have eased 16% since 2005 to around US$98/t in 2007.   Although recent increases in exploration spending suggest a renaissance in the New Zealand minerals sector, long-run trends indicate that we have simply rebounded from a low base over the last five years and much work is still to be done to stimulate further growth in the mining industry to maintain minerals production at current levels. Key industry challenges include marketing exploration opportunities to local and overseas investors, building a critical mass of NZX-listed explorers and providing an internationally competitive environment to attract further capital and expertise.

Jan 1, 2007

By Z. D. Hora

"There has been a number of new developments in British Columbia's industrial minerals field over the past few years. Several new industrial operations were started to diversify the line of British Columbia mineral production by magnesite, perlite and fuller's earth. Industry activities and geological projects have identified occurrences of rare earth minerals, niobium, kaoline, fireclay and zeolites. The Geological Survey Branch significantly improved its database on industrial minerals. New geological concepts based on recent work are opening a number of new opportunities f or further industrial minerals' exploration and development in British Columbia.IntroductionTraditionally, the value of industrial minerals produced in British Columbia in any given year comprises between 100/0and 15% of the combined value of minerals, coal, petroleum and natural gas. Over the years a wide variety of industrial minerals has been produced , often with different levels of marketings success. For some products, such as dimension stone and clay or shale products, initial strong demand gradually dissipated; for others such as asbestos and magnesite, new discoveries or new industrial activities created demand and new markets . In some cases, such as fluorite , talc, pyrophyllite and perlite, wider use has been prevented by small size, poor quality or remote location of the deposits. Also, British Columbia , with 2.6 million inhabitant s, provides only a limited market and the industry therefore has to look beyond provincial borders."

Jan 1, 1990

By Robert Stefanko

A series of workshops were conducted -with invited participants from the coal mining industry to identify the most pressing research and development needs of the industry. Six workshops were held on the following subjects; Research Priorities for Mining-Oriented Universities, R&D Needs-for Surface Coal Mining, R&D Needs for Deep Coal Mining, R&D Needs for Anthracite Coal Mining, R&D Needs for Coal Mine Health and Safety, and R&D Needs far Environmental Control in Coal Mining.

Jan 1, 1975

By A. Vien, A. J. Neale, B. C. Flintoff, R. P. Edwards

Froth flotation is one of the most widely used and effective processes for mineral beneficiation. First introduced in 1911, flotation technology has seen many developments over the past 80+ years. Innovations in reagent chemistry, equipment design, process analysis and process control have given design and plant engineers a powerful set of "tools" for process optimization. However, it does not follow that all flotation systems are optimized. As Klimpel observes: "The problem with the industrial flotation process is that it is relatively easy to get reasonable results, and relatively difficult to get excellent results" Klimpel (I 988). While reasonable was sufficient in the past, competitive forces will make excellent necessary in the future. Judging by the activities in many Canadian plants this transition is already underway. This paper examines the role of some of the optimization "tools" in effecting this change.

Jan 1, 1994

By Karl E. Burgher

Since World War II, the need for the use of explosives with testing, construction, demolition, mining and quarrying near urban areas has increased dramatically. Once remote, testing areas have been encroached upon by commercial and residential areas. Evidence has been found that overpressure levels near these areas can be estimated using meteorological conditions. This paper reviews a study where 205 test shots were fired, meteorological conditions recorded, and over-pressure levels estimated using multiple regression techniques.

Jan 1, 1988

By S. G. Shabestari, S. Saeidinia, P. Mokarian

"The experiments were conducted to investigate the influence of various process parameters in rotary degassing of aluminum alloy AS5U3G. Degassing was carried out by use of argon inert gas. The flow rate of the gas was investigated in the range of 12 to 21 L/min., 350 to 500 rpm rotor speed, 6 to 12 minutes degassing time, and 755°C to 780°C melt temperature. Degassing efficiency was evaluated through measuring the density of RPT samples. By optimizing the process parameters, RPT sample density was increased up to 2.73 g/cm3, which guaranties the production of high-quality aluminum castings. Tensile strength and elongation were increased considerably by degassing process. Scanning electron microscopy (SEM) shows small size and well-distributed microporosity. IntroductionOne of the major problems associated with the casting of aluminum alloys is the formation of gas porosity. Aluminum and its alloys are very susceptible to hydrogen absorption. Because solubility is much lower in solid state than liquid state, hydrogen atoms leave their position during solidification and combine together to form hydrogen molecules. These micrometer- scale cavities, called microporosity, cause the reduction of mechanical properties, particularly strength, ductility, fracture toughness, fatigue resistance, pressure tightness, and corrosion resistance (Laslaz, 1991; Jorstad and Rasmussen, 1993; Sigworth and Wang, 1994; Korasani, 1996; Anson and Gruzleski, 1999; Zhang et al., 2000). To avoid these problems and produce good quality castings, it is necessary to remove hydrogen from the melt. Several methods are available for degassing aluminum melt. One of them is a rotary degassing system using inert gas, e.g. Ar or N2. Various thermodynamic and kinetic factors govern the removal of hydrogen from molten aluminum (Anderson, 1987; Sigworth, 1987; Pignault, 1993; King and Reynolds, 1995). These are some parameters that affect degassing efficiency. Some of them are discussed here and some are examined in this project."

Jan 1, 2004

By C. Demir, M. S. Celik, I. Gülgonul

Na-feldspar (albite) and K-feldspar (microcline or orthoclase) are major feldspar minerals with identical crystal structures and physicochemical properties. Flotation appears to be a unique method of separating these minerals. Fundamental studies on amine/feldspar system in the presence of monovalent salts showed that separation of these feldspar minerals by flotation is possible at certain concentration of monovalent salts in HF medium and natural pH. A comparison between natural pH and HF medium indicates that the latter provides a better selectivity at the expense of higher collector requirement. A general mechanism for both systems involving an ion exchange between the uncommon ions and adsorption of the common ions is proposed to be responsible for creating differences in the charge of albite and microcline unto which amine adsorbs.

Jan 1, 2002

By Lance A. Roberts

Expansive soil formations can be found throughout the United States. When subjected to wetting, these formations have the potential to swell and exert large uplift forces on buildings and foundations. Lightly loaded structures, such as single family residences founded in areas of expansive soils, can be significantly damaged due to uplift movement from swelling actions. Designing an economical deep foundation that can resist uplift forces is critical to prevent damage to these structures. The current solutions to control uplift due to swelling soils, such as over-excavation and replacement of the expansive material or the use of drilled shafts can be costly. Piles made from recycled polymer materials could provide a solution. Due to a lower coefficient of friction along the interface of the soil-pile interface compared to traditional pile materials, solid recycled plastic piles can allow expansive soils to move nearly independently from the pile when wetted. This results in a much smaller magnitude of uplift force being transferred to the structure, which minimizes the risk of significant structural damage from excessive movements. This paper presents the results of research conducted on the use of recycled plastic piles in an expansive shale environment. The preliminary phase of the project involved the installation of six recycled plastic piles at a test site on the South Dakota School of Mines and Technology campus. Two of the piles were subjected to a full-scale compression load test in order to determine ultimate capacity. The remaining four piles were subjected to long-term monitoring of uplift movement during the course of the project. A concrete anchor was also installed at the test site for uplift monitoring. Data gathered during the field and laboratory testing was utilized in a non-linear soil-structure interaction model to predict the displacement behavior and internal stresses within a plastic pile and concrete anchor subjected to uplift forces from the swelling shale. While more research is needed to further understand the application for recycled plastic piles, the results from this research indicate that their use is a viable alternative for support of lightly loaded structures in expansive soil environments.

Jan 1, 2010

SAG Mill Grinding Design Versus Geometallurgy - Getting it Right for Competent Ores Smarter processing for the future, in the area of SAG mill design involves accurate grinding test data, completing final mill design in less than three months, and at a cost of less than US$80 000. More detailed variability testing on the other hand takes longer, is more expensive, and is used for throughput optimisation for an existing or newly purchased mill. This paper shows that SAGDesignTM testing is excellent for new SAG plant design due to relatively low cost per test and the ability to do more testing for a limited budget on larger projects. It also briefly examines a way to develop proper geometallurgical ore hardness information on every block in the mine model, from the more detailed analysis data.

Sep 13, 2010

By J. M. Wempen

As development in underground coal mines progresses away from the critical components of the ventilation system, including the main fans and ventilation shafts, resistance is markedly increased. This results in higher pressure and flow requirements from the main fan(s) to maintain adequate face ventilation, which often requires that the primary ventilation system is upgraded with additional shafts and surface fans. The use of booster fans underground is a potentially practical alternative. This study presents simulations of the use of booster fans in two underground ventilation scenarios, one longwall and one room and pillar. The booster fan effects on the power requirements of the ventilation systems are evaluated.

Jan 1, 2011

By R. J. Gochin, G. D. Schena, R. Spencer

The impact of a mineral project in a developing country is evaluated in the broad context of its economy using input-output models. Minimum economic theory is used to develop simple numerical models. Sets of technical coefficients are exploited in the development of linear models of the productive element of an economy. The analysis allows assessment of the overall economic consequences of a mineral development in which issues broader in scope than financial objectives need to be incorporated in the evaluation. In part 1, the framework for the development of the input-output model is presented. The model is refined to incorporate country-specific behaviour. The increased flexibility of the enhanced semi-input-output model permits a more confident investigation of the economy-wide effects associated with a new project in the mineral sector of a developing country. The relevance of the models is illustrated using an example from Namibia

Sep 1, 1991

By J Graaf, R A. Murrell

Gold Fields Australia is constructing two major ventilation shafts at the Wallaby gold mine in Western Australia. The new ventilation shafts are required to facilitate the long term ventilation strategy for the mine, thereby allowing continued extraction of ore beyond 1000 m below the surface. The construction work has involved all of the challenges that shaft construction can throw up, including challenging geotechnical conditions, unexpected high water inflows and major circulation loss during pilot hole drilling for raise boring. An extensive geotechnical and hydrological investigation program was undertaken prior to awarding the shaft construction contracts. While most of the risks were identified, several proved to be much more challenging than expected. The shaft construction methods included conventional sinking into the fresh rock profile in each shaft, followed by raise bore pilot hole drilling and reaming. A headframe was constructed for the first shaft, which was sunk to 92 m with a stage suspended in the shaft to facilitate the concrete lining and provide rope guides for the kibble winding. Drawing from experience when sinking the first shaft, additional ground pre-conditioning was implemented for the second shaft, which was pre-supported with continuous piles to 28 m followed by sinking to 50 m using a crane instead of winders and a headframe. Following the conventional sinking through the weathered zone in each shaft, the shafts were completed using a raise bore. The first shaft utilised a riser pipe and rotary vertical drilling system (RVDS) with the second shaft having utilised a dual rotary rig for pilot hole drilling. This paper reviews the site investigations undertaken, construction methodologies applied, the results achieved and the lessons learnt.CITATION:Murrell, R A and Graaf, J, 2017. Shaft construction at the Gold Fields Wallaby mine, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 321–334 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

By Elizabeth Gardiner

Tailings and water management facilities are integral components of mine and mill operations. They must be managed for the long term to ensure that safe and environmentally responsible stewardship is achieved. The Mining Association of Canada (MAC) has developed and published two manuals to provide guidance to mining companies on sound practices for the safe and environmentally responsible management of tailings facilities: ???A Guide to the Management of Tailings Facilities; and ???Developing an Operation, Maintenance and Surveillance Manual for Tailings and Water Management Facilities. The Guides were designed to help companies develop and implement tailings management systems that include environmental and safety criteria, to improve the consistency of application of sound engineering and management principles to tailings and water management facilities through their full life cycle, and to demonstrate this to regulators and the public.

May 1, 2003

By Daniel J. Rider

In 1980 the Niagara Frontier Transportation Authority contracted for three miles of cut and cover box structure and station construction in Main Street, Buffalo, New York. Project depths ranged from 30 feet to 60 feet below street grade. Soils, Figure No. 1, consisted of loose to very compact sands and gravels. Ground water level was generally 20 feet below grade. Specifications required a soldier pile and timber lagging support system with external dewatering. Soldier piles were to be installed in prebored holes with bentonite slurry and lean concrete backfill. Conventional pile driving was not allowed due to concerns over excessive noise and vibrations and its effect on nearby historic structures and the surrounding population

Jan 1, 1987

By Thierry Bernard, Jean Marc Laboz

This paper explains why and how integration of EIS (Electronic Initiation System) with dedicated software tools can increase benefits to blasters and at the same time simplify the design of blast sequence

Jan 1, 2000

By K. K. Kelley

Thermodynamics data for silicates have applications in the fields of extractive metallurgy, ceramics, and geochemistry. To facilitate these applications, up-to-date tables of heats and free energies of formation are needed. It is the purpose of this report to supply such tables for anhydrous silicates. During the last 15 years the heats of formation of a substantial number of anhydrous silicates have been reliably determined at or near room temperature. This resulted from the development (first by the Bureau of Mines and later by the Geophysical Laboratory of the Carnegie Institution of Washington, by the Institute of Geology of the University of Helsinki, Finland, and by the Department of Geology of the University of Chicago) of accurate solution calorimeters, employing hydrofluoric acid as the reaction medium. Specific references to work of these laboratories will be made in the next section of this report. Also, entropy data at 298.150 K. and high-temperature heat-content values are available for many of these silicates, mainly owing to work of the Bureau of Mines. Most of these entropy and heat-content data have been compiled in Bureau of Mines Bulletins (13, 15).3

Jan 1, 1962

By S. Cossio, J. L. Noyola, R. Espinosa

"Minera Penmont’s La Herradura is a joint venture between Industrias Peñoles, S.A. de C.V. and Newmont Mining Corporation. The mine is located in the northern Mexican state of Sonora. La Herradura consists of an open pit mine with a two-stage crushing plant and heap leaching facility. Gold is recovered from the pregnant solution using the Merrill-Crowe process; production began in July 1998. La Herradura produces about 130 000 oz gold per year and its treatment capacity is approximately 22 000 t/d. Ore mineralization occurs in a shear zone with quartz and native gold. Gold distribution is quite heterogeneous due to coarse visible gold, which in some cases ranges from 100 to 600 microns.Sampling and assaying protocols were established during exploration and prior to start-up of operations, based on nomographs developed from early heterogeneity tests. However, as the coarse gold problem became noticeable, it was necessary to develop new sampling protocols to have an acceptable relative standard deviation to control the fundamental error within ± 15%.An experimental program was developed and conducted on a selected ore block consisting of 195 blastholes; regular ore grade control procedures were applied to both sets of data to evaluate the difference in results between the protocol established prior to start-up of operations (existing) and the new protocol (leaching). In the existing protocol, sub-sampling is done through riffle splitters, and coning and quartering. Fire assaying was used to estimate the gold content on a 50 g sample. In the leaching protocol, a 12 000 g sample of bottle-rolled cyanide was leached, and the leach residue was assayed on a 50 g sample using fire assaying, and a weighted average total gold content was calculated. Currently, a new alternative method is being evaluated, where sub-sampling is done using rotary splitters, and fire assay on a 50 g sample; in this rotary sampling protocol and for comparison purposes, gold assays were also repeated using the leaching protocol.Test results were compared in three groups: < 0.3 g/t (below cut-off), 0.3 to 0.8 g/t, and >0.8 g/t. Overall, results show that the protocol established prior to start-up of operations underestimates the gold assays. Detailed technical results, alternative options, and their implications are discussed in the paper."

Jan 1, 2004

Information Circular (IC) 9453 Roof falls continue to be the greatest single safety hazard faced by underground coal miners. During1996-99, 44 coal miners lost their lives in rock falls and nearly 2,400 were injured. In addition, nearly 6,000 non injury roof collapses were reported. Roof supports are installed to protect the miners, but support system failures contributed to most of these incidents. Reducing the terrible toll taken by ground falls continues to be a major goal of research by the National Institute for Occupational Safety and Health (NIOSH).During 2000-01, NIOSH conducted a series of open industry briefings on New Technology for Coal Mine Roof Support in Norton, VA, Charleston, WV, Evansville, IN, Tuscaloosa, AL, Price, UT, Glenwood Springs, CO, and Washington, PA. Drawing on many years of research undertaken by the NIOSH Pittsburgh and Spokane Research Laboratories, the proceedings describe what types of coal mine roof support are available, how they work, and when they should be used. The major subjects covered include roof bolts, standing roof supports, cable supports, and longwall shields. Some special topics are also addressed, including an analysis of roof fall accident statistics, techniques for better skin control, and material handling considerations. The proceedings volume also contains information on several important new technologies, which are described for the first time, e.g., guidelines for selecting roof bolt

Aug 1, 2001

By Emil B. Milosavljevic

Problems associated with distillation and other classical methods for analyzing operationally defined cyanide (CATC, WAD, Total and Free Cyanide) will be discussed. These methods often achieve incomplete, species dependent cyanide recoveries and suffer from serious interferences. Depending on the relative concentrations of interferents and other matrix constituents, underestimation (ultimately Type II errors probability of not detecting a constituent when it is actually present) or overestimation (ultimately Type I errors -probability of deciding a constituent is present when it is actually absent) of the cyanide levels present in a ,given sample may occur, causing in the first case false security and in the second case, excessive cyanide treatment costs. Mahy, if not all, enumerated problems can be solved by using novel flow injection (FI) gas-diffusion amperometric methods. A modification of the recently approved FI ligand exchange (FIILE) method for determination of available cyanide (USEPA Method OIA-&apos;l677) that obviates sulfide interference will be discussed. Eight laboratory round-robin data obtained for the FI UV -digestion (FIIUV) method that determines total cyanide (Proposed Method OIA-1678) will also be presented. In addition, some methods for cyanide speciation will be presented. Finally, research needed for developing reliable methods for determination of operationally defined cyanide in solid samples will be summarized.

Jan 1, 1998

By T. K. Dichmann, J. A. Finch

"Microflotation, laboratory batch, and in-plant minicell continuous tests were conducted to determine if copper ions not only activate sphalerite but also depress pyrite when the minerals are together. Microflotation tests showed that pyrite recovery increased with addition of copper ions in the pH range of 5-10 when alone, but decreased when sphalerite was also present. Batch flotation tests (Red Dog ore) showed that upon addition of copper, pyrite recovery decreased significantly. The continuous tests (Louvicourt Mine) confirmed this and indicated that with excess copper pyrite recovery can increase. The results suggest there is competition for copper and xanthate in favour of sphalerite. To take advantage of this competition it may be necessary to control the sequence and rate of copper, collector, and lime addition. INTRODUCTIONFlotation, in common with all physical separations, is an imperfect process that results in misplacement of minerals. One source of this imperfection is accidental activation by contaminating metal ions. An important practical example is the misplacement of pyrite to zinc concentrates. Flotation of sphalerite generally requires activation by copper ions, added as copper sulphate. Copper ions are also used to activate pyrite [l] hence there is the suspicion that accidental activation contributes to the recovery of pyrite (Py) with the sphalerite (Sp). However, recent literature has shown that copper ions may make Py less floatable if Sp is also present. Xu et al. [2] conducted continuous minicell tests in-plant at Kidd Creek Operations (division of Falconbridge Ltd.) and showed that while the addition of copper sulphate improved zinc/iron selectivity, it did so as much by reducing the recovery of pyrite as increasing zinc recovery (Figure 1)."

Jan 1, 2000