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By Glen Smith

Nautilus Minerals, the world?s leader in exploration and development of deep ocean seafloor resources, is today focused on the recovery of high-grade copper and gold in seafloor massive-sulphide mineralization. These targeted mineralized belts, analogous to land-based volcanogenic massive sulphide deposits, are located near plate boundaries in the back arc basins of the Western Pacific. The first deposit to be developed by the company is located at a depth of 1,600 meters at Solwara 1, in the benign waters of the Bismarck Sea. This location lies within the territorial waters of Papua New Guinea. From 2006 to 2009 the company completed detailed environmental and geological studies at Solwara 1, culminating in a number of world firsts, including the first Environmental Permit granted for the extraction of seafloor massive sulphide deposits and the first NI 43-101 compliant seafloor massive sulphide deposit resource statement. Nautilus has relied heavily on proven deepwater technologies from the oil and gas industry in the design of its production system. Pipeline trenching units, workclass ROVs, deepwater production risers and drill cuttings removal systems will be adapted to initiate this new and exciting industry. Key contractors used by Nautilus on this innovative project have all been selected for their deepwater experience (gained in the oil and gas industry), creativity and determination to launch this new industry successfully. Innovation is at the forefront of Nautilus? success to date. This paper summarizes the progress to date of this development which will provide a new source of minerals for the world and which will contribute to sustainable growth for the future.

Jan 1, 2010

"Developing markets for western metallurgical coal have continued to stimulate considerable exploration activity in the Rocky Mountain foothills and to influence major segments of a wide-ranging carbonization R&D pro-gram. Adjunct studies have included expanded petrographie investigations.Coal preparation has• been principally directed toward utilization of prepared small coal and was, like much of the year's combustion work, strongly influenced by concern over atmospheric pollution. Particular attention has been given to desulphurization and to the suppression of pollutants in combustion systems.In the area of non-fuel utilization of coal, interest has centered on plant nutrients and on a series of coal-based carbons which, inter alia, possess utility as filtration media.Other projects included the development of improved sampling and analytical methods, investigations into the effect of storage on coal proper-ties and R&D in solids pipelining. In addition, a significant volume of basic 'uncommitted' research has been maintained."

Jan 1, 1968

By P. M. Gruzensky

A survey of the literature has been made covering the extraction of bismuth from raw materials, its separation from lead, and its subsequent refining. The use of aqueous, nonaqueous, and fused electrolytes in electrolytic refining is reviewed. This literature survey has been prepared preliminary to some proposed investigations concerning the electrometallurgy of bismuth, and, although an effort has been made to cover a majority of the applicable references, a critical review was not attempted and no assertion is made that this manuscript is exhaustive in nature. Titles of publications in parenthesis are translations from the language in which the reference was originally published.

Jan 1, 1954

By J Hadjigeorgiou

Narrow vein mining, as most types of mining, faces important geotechnical challenges. The specificity of geotechnical challenges in narrow vein mines stems from the nature of the deposits, which are often inclined, discordant and found within fractured rock or faults or in shear zones within country rock. This complicates the construction of representative geomechanical models and limits the applicability of several engineering design tools. Furthermore, in certain cases, the severity of encountered geotechnical problems is considerably greater in narrow vein than in wider orebodies. This paper provides an overview of geotechnical and other challenges in narrow vein mines with a focus on how these are currently addressed. Of particular concern is the use of manual labour working close to the mining face where there is greater exposure to geomechanical hazards. This review concludes with a particular emphasis on understanding the limitations of commonly used engineering tools and techniques to address geotechnical problems in narrow vein mines.CITATION:Hadjigeorgiou, J, 2012. Geotechnical challenges in narrow vein mining, in Proceedings Narrow Vein Mining 2012 , pp 15-22 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

By Côme Carbonneau

The ten -year case history of La Société Québécoise d'Exploration Minière (SOQUEM) is reviewed under the headings of the company's raison d'être, objectives, policies, structure and final goal. A brief analysis of its past operations is presented: aborted efforts, findings and developments. A projection is made of the future earnings, in terms of estimated present value, of its three main discoveries - Louvem , Niobec and Selim.

Jan 1, 1978

By Bogidar Mihaylov

A laboratory study was conducted on continuous precipitation of copper, cadmium, mercury and arsenic using thiourea, thioacetamide, sodium sulfide and ammonium sulfide as precipitating agents. Depending on the experimental conditions the metals precipitate with the sulfide donors at different orders and rates. These differences were employed as a basis of several techniques for continuous separation of copper and arsenic, cadmium and arsenic, mercury and copper, and copper, mercury and arsenic. The separation of the metals from industrial waste solutions was also studied. The precipitates obtained were inspected using x-ray diffraction, scanning electron microscope, atomic absorption spectrometer and plasma particle counter.

Jan 1, 1992

By E. Craig Simmons

Uranium is an element incompatible with respect to the major rock-forming minerals crystallizing from granitic magma, entering in- stead trace minerals such as zircon. The relationship between the saturation limit (SL) for such a mineral and the bulk distribution coefficient (Do) for U is central to understanding the distribution of U and its availability to late- stage fluids which can form ore deposits directly, or labile U which can be remobilized later. Low SL values imply early crystallization of zircon, but in very small proportions, minimizing Do and maximizing the degree of enrichment of U in late-stage fluids. Thus, granitic rocks with low Zr contents (due to a low saturation limit for zircon) are most likely to evolve U- enriched differentiates; this will be reflected in a high U content of the zircons (but not necessarily high U abundances in whole-rocks). Thus, the ratio of the U content of zircon to the Zr content of the corresponding whole-rock is potentially a very useful parameter in identifying granitic rocks which are most likely to have U-enriched solutions associated with them. The granitic rocks associated with the U deposits of the Midnite Mine area, Washington, have geochemical characteristics which fit very well the model presented here. The rocks are very low in Zr (100 ppm) and contain zircons with extremely high U contents (3,000-4,000 ppm).

Jan 1, 1981

By M. Fall

The progressive depletion of ore available at shallow depths in several underground mines around the world means that underground mining operations would increasingly be carried out at greater depths and therefore at higher temperatures. However, our understanding of the effect of hot temperatures on the response (mechanical, economical, environmental) of cemented paste backfill (CPB) is still limited. Hence, an extensive laboratory investigation was conducted to study the performance of young and aged CPB, in response to deep mine temperatures. Several CPB samples with different compositions, cured at different temperatures (20 to 50°C) and different times (7 to 160 days) were tested regarding their mechanical properties, economical performance (binder consumption) and microstructural properties. The results show that hot temperatures significantly affect the performance properties of CPB at young and advanced ages. An increase in the curing temperature leads to a considerable improvement of the rate of gain of CPB strength and also to a significant increase of the strength of CPBs studied. CBP samples cured at hot temperatures show lower binder consumption and finer pore structure. Results of this study could serve as background information for the development of optimal mine backfill design procedures.

May 1, 2007

By Dmitriy Makarov

The paper presents the modeling and analysis of oxidation of pyrite copper-zinc ore samples from the Letnee, Yaman-Kasy and Valentorskoye deposits. It is found, that the oxidized samples contain copper and zinc sulfates that are leached under the sample and water contact. It is shown, that sulfide floatability is decreased by the longer-term oxidation.We advise to improve nonferrous metals recovery by joint leaching and ultrasonic treatment of oxidized compounds. Study of the geotechnological processes of non-ferrous metal extraction, on the basis of two copper-zinc ore deposits shows, that heap leaching is of little use for the ores of the Letnee deposit. Leaching results for the Yaman-Kasy ore showed more promise.

Sep 1, 2012

By Y. C. Kim

The strongly skewed grade distributions and the need to estimate the local recoverable reserves in a selective mining environment are the two problems that Ordinary Kriging (OK) cannot easily handle. With the recent introduction of the nonparametric, distribution-free technique of Indicator Kriging (IK), the above problems can be solved. This paper describes the results of performance evaluation of IK in an open-pit gold-silver deposit. For performance evaluation, the predictions of local recoverable reserves using IK were compared with the actual reserves based on blast hole information. The IK estimator, although a bit optimistic, performed very well in predicting the total recoverable ounces of gold from each panel on a test bench. The OK estimator was also used to try to predict local recoverable reserves, by treating each panel as either waste or ore, depending on the panel's average grade. Under this criterion. OK was found to be very biased and pessimistic.

Jan 1, 1986

By A. Banerjee, J. P. Weiler, J. Jekl, J. T. Wood, R. Berkmortel

"The work presented here is part of an ongoing project designed to develop predictive capabilities of the local mechanical properties, and thus, structural behaviour of a thin-walled high-pressure die-cast AM60B magnesium alloy component. This work focuses on developing correlations between process parameters and local microstructure. Numerical simulations of the die filling and solidification behaviour of the AM60B component were used to estimate local process parameters such as solidification rate, temperature gradient, filling velocity, etc. These estimated parameters were used to establish semiempirical correlations with measured VALUES (of the local microstructure measured in regions throughout the component of different solidification conditions. INTRODUCTIONHigh-pressure die-cast magnesium alloys are experiencing increasing use in structural automotive components. A strength-to-weight ratio comparable to steels and its ease of castability allow for these alloys to be utilized in such capacities as instrument panel beams, seat and door frames, and engine cradles, among others (Gjestland and Westengen, 2007). However, the current use of these alloys is limited due to variations in local mechanical properties. These local property variations restrict part designers to assume lower than actual properties, resulting in larger sections, thus diminishing the light-weighting advantages of magnesium alloys. If these local property variations could be predicted, part designers would be able to optimize die-cast magnesium alloy components and fully take advantage of the light-weighting capacity of these materials.The work presented here is part of an ongoing project aimed at developing predictive capabilities of the local mechanical properties, and bulk mechanical performance, from variations in local microstructure, and ultimately from local process parameters in die-cast magnesium alloys. This project, unique in its nature, is based upon the results determined from fifty sequentially cast AM60B magnesium alloy instrument panel beams provided by Meridian Lightweight Technologies (shown in Figure 1)."

Jan 1, 2012

By Mark Tsirlin

Kinetics of the initial oxidation stages of diffusive silicide coatings on 8 molybdenum and niobium at 1100 - 1700 and under the pressure of 400 and 1330 Pa has been studied using methods of gravimetry and gas phase analysis of oxygen, as well as by SEK, XRD and EDMA methods. The first oxidation stage described by asymptotic equation in case of NbSi coating changed over to the stage described by parabolic equation. The asymptotic law was shown to depend on non - stationary conditions on the oxide layer boundaries. Interconnection between silicides and quartz structures, on the one hand, and peculiarities of oxidation kinetics, on the other, is [discussed. The possibility of estimation oxygen atom jump frequency in quartz and fractions of oxygen reacting with metal and with silicon proceeding from the analysis of the kinetic data was ascertained. Conditions of oxidation kine- tics transfer from asymptotic (or parabolic) stage to a non - protective "linear" stage, associated with volatile ~roduct formation, are also discussed.

Jan 1, 1995

By J. F. Shultz

The Bureau of Mines investigated the hydrogenation of carbon monoxide and carbon dioxide over Raney nickel catalyst and nitrided fused-iron catalyst using both a single-pass and a recycle system. Activation energy over Raney nickel catalyst is 29 to 32 kcal/mole for synthesis from either CO or CO2, Pressure dependence of the gas conversion is to the 0.3 power for synthesis from CO and to the 0.5 power for synthesis from CO2. Nitrided fused-iron catalysts were tested using high recycle rates and 3H2+lCO, 2H2+lCO, and 1H2+lCO feed gas at 21.4 atmospheres absolute pressure. The relative usage of hydrogen (moles H2 consumed per moles Ha+CO consumed) was larger than in corresponding single-pass tests, and the relative usage of hydrogen approached the feed gas ratio monotonically as conversion increased. Activation energy was found to be 12 or 13 kcal/mole fresh feed gases of 3H2+lCO or 2H2+lCO. For single-pass operation the activation energy under the same conditions was 19 to 21 kcal/mole.

Jan 1, 1967

Cuspidine (3CaO?2SiO2?CaF2) is one of the most important compounds crystallized in mold flux films during casting in the continuous casting process of steel. The primary crystallization field of cuspidine has been experimentally developed in the CaO-SiOrCaF2-SiF4 system. The cuspidine-NaF binary and cuspidine-CaF2-NaF ternary systems have been also experimentally determined to study effects of addition of NaF on the primary field of cuspidine. In order to discuss its thermodynamic stability the standard Gibbs energy of formation of cuspidine has been determined by an electromotive force method using CaF2 as solid electrolyte and a transpiration method as follows: The chemical potential diagram and constituent activities for the CaO-Si02-CaF2 system have been evaluated based on the obtained thermodynamic data.

Jan 1, 2003

By F. E. Wagner, L. J. Cabri, Y. G. Safonov, N. S. Bortnikov, A. D. Genkin, J. Friedl, G. N. Gamyanin

"A multidisciplinary investigation (including INAA, SIMS, EPMA, and Mossbauer Spectroscopy) was used to characterize gold in four of the largest Siberian mesothermal sulfide gold deposits. These are the Olympiada (""'750 metric tons gold) and Veduga (estimated at 75-100 metric tons gold) deposits in the Enisei Mountain Range and the Nezhdaninskoye (z500 metric tons gold) and Sentachan deposits in the Verchoyansk-Kolyma area. It was found that some of the mineralization is refractory in all four deposits, largely due to the occurrence of ""invisible"" gold in arsenopyrite as well as within pyrite, but with a lesser concentration. The gold concentration and its distribution varies considerably both within and between arsenopyrite grains, with implications for processing options such as heap leaching. The ore most likely to be amenable to heap leaching is the oxidized ore of the #4 orebody of the Olympiada deposit, but further quantitative mineralogical investigations are recommended for this orebody's sulfide ore and for the ores of the Nezhdaninskoye deposit. Following a full mineralogical characterization, it is possible that economic viability will depend on a combination of pre-concentration with or without pre-treatment, followed by heap leaching of some tailings products.Acknowledgements· The Russian authors performed this study under an ""Eco res"" Project which was financially supported by the Ministry of Science and New Technology of the Russian Federation. C.J. Stanley wishes to thank John Spratt and Terry Williams for help with EPMA. F.E. Wagner acknowledges the Deutsche Forschungsgemeinschaft for a grant supporting the Mossbauer studies. L.J. Cabri is grateful to the following: M. Beaulne, D. Carson and J.H.G. Laflamme for technical support, K.E. Haque for technical comments, and D.M. Hausen and W. Petruk for editorial suggestions."

Jan 1, 1997

By Arthur B. Johnson

The Bureau of Mines investigated the concentration characteristics of high-clay sylvinite ores from four potash companies operating in the Permian Basin near Carlsbad, N. Mex. These ores, containing 13 to 22 percent K20 and 3 to 7 percent clay slimes, cannot be effectively processed by current commercial flotation methods because of their high slime content. A solution to this problem was shown to be the use of two-stage moderate scrubbing conditions and washing of the ore as opposed to strenuous attritioning. Bench-scale physical beneficiation techniques for recovering potash minerals and the development of ore-dressing systems by flotation resulted in obtaining acceptable product grades and recoveries. By using a coarse grind, emphasis was placed on production of premium granular and coarse products. Flotation results showed that concentrates of 58.7 to 60.4 percent K20 with recoveries of 71.0 to 83.4 percent 0f the K20 values can be obtained.

Jan 1, 1971

By L. V. Wade

The use of longwall/shortwall mining systems is under increasing scrutiny by the U. S, coal industry as a means to reverse the decline in productivity. The success of these mining systems depends to a great extent upon designing the system hardware to best suit local conditions. Of particular importance in this regard is designing the various elements of the total ground support system, including face, face end, and gate road supports, to accommodate local geologic conditions. This presentation centers on the problem of selecting the face support system. The existing geologic situation can influence the selection of the face support hardware in a variety' of ways. In general terms, these influences can be grouped into the following four areas: 1. The capacities required of the support unit; 2. The roof, coverage supplied by the support units; 3. The flexibility required of the support unit to meet changing geologic conditions; and 4. The required stiffness characteristics of the individual support units both vertically and horizontally. The following will center on the first area, i.e., the required d capacities of the support unit, in particular, the maximum required load density for a particular geologic situation.

Jan 1, 1976

By B Reid

"Since the commencement of mining operations at the Cowal Gold Operations (CGO) in 2005, reverse circulation (RC) drilling has been the preferred method for grade control (GC) sample collection. This method was selected because it allowed:for multibench drilling (20 m hole depths for two benches of mining) to aid mine planning increased data density for comparison against the wide spaced ore reserve model angled drill holes to intersect perpendicular to the strike and dip of the shallow dipping mineralisation ability to take two metre sample intervals to enhance the understanding of the mineralisation’s short-scale variability and provide the ability to flitch mine.From June 2008 to December 2013, RC GC was performed using a UDR rotary cone splitter. The field duplicate data over the period displayed strong precision, with a correlation coefficient of 0.94 and an average relative per cent difference (RPD) of 21 per cent for gold. Up to 66.1 per cent of field duplicate data greater than 0.1 g/t fell within ±20 per cent RPD. This is within limits of industry best practice. The Mine to Mill reconciliations over the same period showed the estimated GC grade was 7.7 per cent lower than the calculated head grade (CHG).In December 2013, the Progradex sampling system (PGX) was introduced at CGO due to its advertised ability to capture 100 per cent of the drill cuttings for the complete sample interval, inclusive of fines. Analysis of field duplicate data indicates that since the introduction of the PGX, the sample precision has drifted. From January 2014 to February 2016, the correlation coefficient was 0.92 and up to 51.2 per cent of field duplicate data, greater than 0.1 g/t fell within the ±20 per cent RPD. Over the same 26 month period, the Mine to Mill reconciliation improved to one per cent lower than the CHG. Granulometric analysis of the RC samples collected from the PGX indicated the fines material(<212 µm) averaged up to 22 per cent of the samples mass and following assay determination, the fines material represented a weighted average of 31 per cent of the total gold content within the sample.This paper highlights the:importance of the complete capture of all drill cuttings during an RC drill programinfluence of fines material on the sample quality and accuracyimpact sampling of the fines material has on the Mine to Mill reconciliation performancechallenges experienced in commissioning a PGX system.Citation:Reid, B, 2016. A Fine Looking Sample - the Importance of Fines in Grade Control Sampling to Mine to Mill Reconciliation, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 28–38 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By Thomas V. Fame, William E. Porter

"As geological and mining conditions become more complex, and as overall mining economics become more marginal, short- and long-range decision-making regarding multiple-seam surface mining becomes more difficult. The decision-making problem involves a study of economics, cut-off grades and ratios, equipment capabilities, sequencing and selective mining practices.This paper is concerned primarily with multiple-seam mining of bituminous coal. The research has led to the development of an economic decision-making model for use as a day-to-day tool to aid mine operators and pit geologists to decide what and how to mine.The model is designed as an aid for feasibility decision-making in multiple-scam situations and for situations where selective mining is needed or desired. In effect, a simulation of the feasibility and preliminary mine planning phases has been developed. The model is divided into four separate segments: decision-making, simulated mining, cost calculations and the determination of the discounted cash flow return on investment."

Jan 1, 2014

By Pengfei Wang, Guorui Feng

"The angle of break is the acute angle created by the coal seam bedding plane and caving line formed by roof strata movement after extraction of a longwall panel. It has a significant influence on stress redistribution both in the gob and abutment. Throughout numerical simulation investigations up to now, little attention has been paid to it, or an angle of break of 90° was used, which, however, is not realistic. This paper presents a detailed numerical modelling incorporating the angle of break against Zhenchengdi Coal Mine. The angle of break was obtained through cross-measure boreholes. Hoek-Brown constitutive model was used to simulate the rock masses. Double-yield constitutive model, which was best fitted by Salamon’s model, was used to simulate the gob. The results show that a “/ \ shape” shear failure zone develops around the gob. The shear failure in the floor along the panel edge is due to opposite shear of rock mass on two sides of the caving line, and the number of yielded zones within the gob floor close to the gob edge is smaller. According to the research, the entry was determined to be driven under the gob edge employing split-level longwall panel layout (SLPL). The other numerical simulation for SLPL shows that stress around the god-side entry is much smaller than pre-mining stress, and the area of intact rock mass at the elevating section is larger than conventional layout. Numerical modelling was then validated by field observation.INTRODUCTIONTo solve low recovery and ground control problems in longwall mining with top coal caving (LTCC) due to large gate pillar or chain pillar, gob-side entry approach is becoming increasingly popular (Nazimko, 1994; Li et al., 2016; Zhao, Wang, and Su, 2017). Gob-side entry is actually a combination of the gateroad, pillar, and gob, which is a typical panel layout with slender pillar or artificial pillar or wall. The abutment load has a profound impact on stability of the gate pillar, as well as the gob-side entry. Better estimates of abutment loading profiles will result in improved evaluations of design of pillar and gob-side entry (Larson and Lavoie, 2016)."

Jan 1, 2018