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By J. Handin, S. J. Bauer, M. Friedman

Deformation mechanisms in room-dry and water-saturated specimens of Charcoal Granodiorite, shortened at 10-4s-1, at effective pressures (Pe) to 100 MPa and temperatures to partial melting (?1050°C) are documented with a view toward providing criteria to recognize and characterize the deformation for geological and engineering applications. Above 800°C strength decreases dramatically at effective pressures ? 50 MPa and water-weakening reduces strength an additional 30 to 40% at Pe = 100 MPa. Strains at failure are only 0.1 to 2.2 percent with macroscopic ductility (within this range) increasing as the effective pressures are increased and in wet versus dry tests. Shattering (multiple faulting) gives way to faulting along a single zone to failure without macroscopic faulting as ductility increases. Microscopically, cataclasis (extension microfracturing and thermal cracking with rigid-body motions) predominates at all conditions. Dislocation gliding contributes little to the strain. Precursive extension microfractures coalesce to produce the throughgoing faults with gouge zones exhibiting possible Riedel shears. Incipient melting, particularly in wet tests, produces a distinctive texture along feldspar grain boundaries that suggests a grain-boundary-softening effect contributes to the weakening. In addition, it is demonstrated that the presence of water does not lead to more microfractures, but to a reduction in the stresses required to initiate and propagate them.

Jan 1, 1982

By R. Feenstra

In the course of time, an increasing number of investigations on jet cutting all kinds of material, such as rocks1, 2, 3, metals4, 5, and wood6 have been reported to serve various applications. This paper deals with one particular application of jets, viz deep-well drilling for hydrocarbon exploration and production. A number of papers have been published on this subject 7, 8, 9, some of which refer to jets purposely containing abrasives, termed 'jetted particle drilling'7. Since such abrasives complicate fluid handling considerably and do not appear to be absolutely necessary for making hole we have restricted ourselves to conventional drilling fluids. A large part of our investigation has been performed with the aid of three laboratory-type drilling machines, which permit tests on both micro-bits (12 in) and full-scale bits (62 - 9 5/8 in). In view of the application of jets in deep wells, care has been taken to simulate hydrostatic pressures as they exist in the field on the hole bottom. These have been found to have a major effect on the bit-penetration rate for various drilling fluids. Following experiments with single nozzles, laboratory bits have been designed, improved further and developed for field use. Field runs on 9 5/8 in bits, using conventional equipment and pumps, served to verify the feasibility of the jet drilling concept. Further efforts are evidently needed to evaluate the jet drilling method. It is encouraging that one of these10, a field test programme, is supported by a number of oil companies jointly. Such a combined effort is of paramount importance to evaluate and develop this new method of drilling to its full potential in a reasonable period of time. This paper aims to contribute to that ultimate goal.

Jan 1, 1974

By J. N. Van der Merwe

"Platinum is a highly valuable resource, its safe and economic extraction is paramount. The success of platinum mining by the bord and pillar method depends heavily on a comprehensive and dependable pillar design method. Pillars need to be large enough to safely support the load and small enough to avoid loss of resources. A critical evaluation of current pillar design systems used in narrow-reef platinum mining was undertaken using practical experience from a large feasibility-stage platinum exploration project, supplemented by observations from several platinum mines in Zimbabwe. An extensive literature survey was undertaken in order to determine the current status of design systems. Through this approach, the shortcomings of current pillar design systems are highlighted. Areas are proposed for further research to obtain a better understanding on how additional factors influence pillar system stability. The exploration work highlighted how rock mass classification methods can be utilized in determining the overall strength of pillars. Current pillar design systems for narrow-reef platinum mining consider width-to-heightratio (usually with different exponents for width and height) and the strength of the pillar material. However, there are many more important factors that are not considered and which have a bearing on pillar system stability. An in-depth study of these parameters with a view to establish effective narrow- reef platinum mining pillar design systems needs to be undertaken. IntroductionPillars have been used as a means of support since the early days of mining. Pillarsupported mining methods such as bord and pillar require a reliable design system for them to be successful. This paper presents an evaluation of the current hard-rock mining pillar design systems as applied to a practical large-scale narrow-reef platinum mining feasibility study. It is vital to have a dependable pillar design system for economic and sustainable mining. Using an extensive database collected from the project, the pillar strength formulae were tested and several discrepancies noted. This necessitates the establishment of more reliable pillar design systems. In narrow-reef platinum mining, large compressive stresses accompanied by geological and geotechnical factors contribute to pillar instability. A well-formulated pillar design system is required that accounts for such factors so as to minimize pillar failures."

Jan 1, 2017

By S Coward, S Jackson, S Moayer, J E. Vann

The variability and uncertainty of mineralisation, coupled with subsequent uncertainty in mining and processing, is often paid scant regard or overlooked during the evaluation of mining projects. In many instances, when the project transitions to the operational phase, the reality of feed or product variability and the consequences of unquantified uncertainties throughout the value chain become obvious. The outcome is the familiar picture of frequent ramp-up underperformance and failure to deliver on planned targets and objectives.Both mine and exploration geologists are expected to generate mineral deposit models that are based on an integration of diverse sources of data. These multifaceted deposit models already play a pivotal role in the design, development and optimisation of mining project value, and the trend to a fully digitally engineered future means that this importance is increasing. It is therefore vitally important that tools be made available to the geologist (as well as mining engineers and metallurgists) that enable them to characterise and assess variability and uncertainty via appropriate deposit models and thus articulate their impact on potential project configurations and decisions. Scenario-based project evaluation (SBPE) provides a framework for full and proper analysis of the downstream impacts of inherent deposit variability and uncertainty on project performance.SBPE has been developed by the authors over several years and aims to propagate geological uncertainty and variability through the mining value chain. The outcomes of SBPE can be tested against future external scenarios capturing financial, economic and socio-political factors that also drive project performance. Stochastic representations of the orebody (via conditional simulation (see Chilès and Delfiner, 1999)) that explicitly incorporate variability and represent uncertainty are propagated through the value chain on a block-by-block basis (ie on a much more granular basis than traditional project evaluation approaches).Conventionally, metallurgical processes are modelled with deterministic equations (eg regression models) based on limited data. The SBPE approach allows for the modelling of process performance uncertainty using geometallurgical sampling fully. Multiple outcomes of SBPE are passed through financial modelling, which can also incorporate stochastic components, thus allowing full quantification of the risks and opportunities of a set of project alternatives. The value of the SBPE system is that once a base case has been established, multiple engineered alternatives coupled with external scenarios are easily evaluated and compared in terms of incremental value.A new case study of SBPE is presented that shows how, by analysis of the various aspects of variability and uncertainty, project managers are able to focus on the areas that have the greatest ability to reduce risk and/or add significant value. This can lead to sufficient flexibility being built into operations that allow operators to cope with the real orebody delivered to the plant.CITATION:Jackson, S, Vann, J E, Coward, S and Moayer, S, 2014. Scenario-based project evaluation – full mineral value chain stochastic simulation to evaluate development and operational alternatives, in Proceedings Ninth International Mining Geology Conference 2014 , pp 21–32 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By William H. Lehr

A 4200 ton-per- hour marine transfer terminal, where river and oceangoing vessels simultaneously exchange cargos of coal and phosphate rock, is now in operation near the mouth of the Mississippi. Its materials handling machinery includes a bucket ladder barge unloader; a rope operated clamshell bucket unloader; a coal loader; and a rail mounted bucket wheel machine. The design and operation of this equipment is described as are the docks and conveying, breasting and barge-haul systems in use at the facility. Design considerations imposed by soil and river conditions, geography, operating needs and investment requirements are discussed. The economic significance of design and shipping innovations introduced by this facility is noted.

Jan 1, 1967

By C M. Stewart, P Bowen

McArthur River Mine, in the Gulf Country of the Northern Territory, exploits one of worldÆs largest deposits of zinc, lead and silver. It was officially opened in September 1995, 40 years after its discovery in 1955. This paper describes the geological, engineering and metallurgical assessments which made up the feasibility study. It then relates how these study components compare with the first two years of operation. The challenges that had to be overcome before the McArthur River Mine became economically viable included the metallurgical problems associated with extremely fine grained ore and the development of an effective mining process.

Jan 1, 1998

By M. Orchin

THIS PAPER is concerned with two aspects of the behavior of coal: (1) Dispersion by solvents atmospheric pressure and high temperature and (2) the destruction and regeneration of the coking properties of coal. Several pure polycyclic compounds and a coal-tar fraction were found to extract 95 percent of the organic material of a bituminous coal. About 20 percent of the extract was soluble in benzene, and this fraction contained the ?coking principle? of the coal. From an extensive chemical spectroscopic, and x-ray study of the benzene-soluble material, some conclusions could be drawn concerning the composition and structure of this fraction of coal. A possible commercial application of the extraction technique is in the preparation of low-ash carbonaceous material for the manufacture of electrode carbon.

Jan 1, 1951

By Arthur E. Morris

Fifty years ago when Professor Yazawa began his career, the field of process simulation and modeling was in its infancy. Since then, tremendous progress has been made in our ability to model metal production flowsheets from mine to refined metal. This progress has come about by parallel developments in basic understanding of process chemistry and in computational techniques, This paper will review the progress made in process understanding and modeling in lead, zinc, and copper metallurgy from its inception to the present, and the role of Professor Yazawa's work in furthering this progress. Specific examples will be given for the sintering of lead concentrates, slag fuming, zinc concentrate roasting, flash smelting of copper, and pyro-extraction of zinc. Factors limiting further progress will be described.

Jan 1, 2003

By K. S. McClure, S. B. Chitralekha, R. B. Gopaluni, Chmylek. T., S. L. Shah

This is a tutorial paper on industrially successful approaches for nonlinear process monitoring. Online process monitoring is essential to continuous operation of plants at high efficiency. The problem of process monitoring is one where an impending but undesirable process condition has to be identified and used to alert process engineers. This problem has traditionally been solved by practicing engineers using statistical techniques that detect a change in the underlying correlation structure of process variables. For linear correlation structures, algorithms such as principal components analysis, independent component analysis and partial least squares have been proposed. However, many industrial processes exhibit nonlinear correlation structure between the process variables. In this tutorial we describe various nonlinear monitoring techniques and elaborate on two recently developed methods, namely Support Vector Machine and Local Linear Embedding. The two methods are evaluated by application on two experimental case studies, a SAG mill and a polymer extruder.

Jan 1, 2014

By S. J. Baumgartner

The ferromanganese industry is under pressure to deal with the slag arising from the production of ferromanganese, which is discarded in landfills or slag heaps. This material poses an environmental and health risk to surrounding ecosystems and communities, and disposal costs are increasing. Ferromanganese slag contains an appreciable amount of residual manganese metal, which can be exploited. Previous work has shown that the slag can be leached fully, while rejecting the silica to a residue. The methods that were investigated to recover manganese from the leach solution included hydroxide precipitation to upgrade the leach solution followed by manganese carbonate precipitation to produce a pure manganese carbonate product or a manganese carbonate furnace feed material, which would be recycled to increase manganese recoveries in the production of ferromanganese. In addition, electrowinning of electrolytic manganese dioxide from the leach solution was studied. The methods were compared in terms of selectivity, costs, and product quality. Co-recovery of the leach residue, which is a potential cement additive, is discussed. Among the methods investigated to upgrade the pregnant leach solution, hydroxide precipitation utilizing ammonia to adjust the pH appears to be the most effective in removing major impurities such as iron, aluminium, and silica to less than 1 ppm. The manganese carbonate and impure manganese carbonate furnace feed products met quality specifications. However, although the production of these materials was technically viable, the large amounts of base reagent that were required to raise the pH, and the associated high operating costs, rendered the process uneconomic. An optimization study was therefore carried out with the primary objective to determine the ideal acid amount to be utilized in the waterstarved digestion stage, thereby decreasing acid and base consumption while optimizing the quality of the pregnant leach solution, and producing a leach residue that contained <1% Mn. The outcome was an economically viable process. Additional benefits included an increase in the manganese content of the impure manganese carbonate furnace feed material, and a substantial reduction in the dilution of the pregnant leach solution, thereby maintaining high manganese concentrations that rendered the solution viable for electrowinning of electrolytic manganese dioxide, the production of which yielded a current efficiency of 74%.

Jan 1, 2014

By A. E. Back

A method has been developed in the laboratory for successfully treating titaniferous magnetite ore from the deposit at Iron Mountain, Wyo. The ore is roasted with 15 percent sodium carbonate to convert the vanadium to a water-soluble form and fix the soda for the subsequent electric-smelting step. Approximately 90 percent of the vanadium is recoverable in a product assaying 80 percent V2O5. The leached calcine is briquetted and smelted in a graphite-lined electric-arc furnace. Substantially all of the titanium is recovered in a soda slag, assaying 60 percent TiO2 and 2 percent Fe, which can be upgraded to 75 to 80 percent TiO2 by leaching with dilute sulfuric acid. The upgraded slag could be utilized for the production of titanium dioxide pigments or titanium tetrachloride. About 90 percent of the iron is recovered as pig iron, containing only minor amounts of vanadium, titanium, and sulfur. The high TiO2 slag compares favorably with slag containing about 70 percent TiO2 being produced by the Quebec Iron & Titanium Corp. at Sorel, Quebec. The data obtained from this investigation indicate that a feasible process has been developed for treating Iron Mountain ore, and larger-scale testing is warranted to develop engineering data for the ultimate utilization of this deposit as a source of titanium, iron, and vanadium. There are adequate supplies of basic raw materials, electric power, water, sodium carbonate, coal, and petroleum products within fairly short distances of Cheyenne and Laramie, Wyo., the nearest cities and probable plant- and labor-supply points.

Jan 1, 1952

By J. A. Finch

Individual mineral cyclone performance curves were determined for the four major minerals at two lead-zinc concentrators. Sizing was by screen and cyclosizer down to approximately 10 um, with lead , zinc and iron as saying of each size fraction. The performance curves were similar in shape and located according to the mineral specific gravity, Pm. The curves displayed a discontinuity at the fine end and a magnitude of short-circuiting of fines to the underflow which increased with Pm. Mass fraction of water to the underflow was only a guide to this short-circuiting. Sharpness of separation seemed in dependent of Pm. An inflection in the over-all performance curve was shown to be a consequence of the individual component mineral performance. A general relationship was observed showing that the flow regime of classification changed from laminar/ intermediate to turbulent with increasing cyclone feed size. Individual mineral size reduction for the four major minerals at one of the concentrators was also determined. Size reduction of the silica was greater than that of the galena, in contradiction to their accepted relative grind-ability. The observation did correlate with silica being much coarser than the galena in the feed to the ball mill. It is suggested that the silica acted as a buffer to the galena.

Jan 1, 1977

By J. S. Fox

Major-element data for unaltered, unmineralized felsic host rocks from a number of stratigraphically simple, massive volcanogenic Zn-Cu(-Pb) sulphide deposits of low metamorphic grade have been compiled. The petrochemical affinities of these host rocks have been determined (by standard means and by discriminant analysis) and compared. This comparison indicates that volcanogenic deposits in felsic terrains are not restricted to the classical calc-alkaline rock association as previously thought, but can actually be hosted by rocks showing a range of iron content. There is a positive correlation between differentiation trend and are tenor. Zn-Cu ores usually have iron-rich felsic hosts (most Canadian Shield deposits); Pb-Zn -Cu ores have iron-poor felsic hosts (Japanese, Iberian and Tasmanian deposits). This parallels the antipathetic relationship between iron content and background lead levels evident in young, unmineralized, island arcs as well as in many older belts. Correlations between differentiation trend on one hand and massive ore mineralogy and the relative proportions of various rock type (including rhyolite, quartz-porphyry and coarse pyroclastic rocks) on the other are also evident. It is concluded that the recognition of a calc-alkaline differentiation trend cannot be used as a prospecting guide, as has previously been proposed. However, in view of the above correlations, the recognition of a given trend may aid in the formulation of an effective exploration philosophy.

Jan 1, 1979

By H Askari-Nasab, E Torkamani, M M. Badiozamani, S P. Upadhyay, M Tabesh

"Decision-making in mining is a challenging task. Optimal decisions regarding shovel and truck allocations, aligned with the optimal short-term production schedules, are crucial in keeping the operations in line with the company’s long-term objectives. In this paper, we present two main modelling components as the means to achieve near-optimal operational plans: a mixed integer linear goal programming model to allocate trucks and shovels to mining faces over a shift-by-shift basis so that operating costs are minimised and resource utilisations are maximised through the planning horizon a discrete-event simulation model to investigate the behaviour of a truck-and-shovel haulage system in the presence of uncertainty within mining operations. The goals integrated into the mathematical model are to: maximise production minimise deviations from the target head grade minimise deviations in tonnage feed to the processing plants from the desired feed minimise operating cost.The mathematical model provides shovel assignments and the target productions as an input to the discrete event simulation model while meeting the desired goals and constraints of the mining operation. We illustrate the applications of the discrete event simulation model by presenting a large-scale oil sands case study. The main contribution of this work thus far is the development, implementation and verification of a simulation model with a link to optimal short-term mine schedule and extraction sequence of mining faces, which assists in achieving a high level of mine plan compliance across short-term planning and operational planning time horizons.CITATION:Askari-Nasab, H, Upadhyay, S P, Torkamani, E, Tabesh, M and Badiozamani, M M, 2014. Simulation optimisation of mine operational plans, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 299–312 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 24, 2014

By Brian Stimpson

A recent study by the National Academy of Engineering concluded that if the U.S. Coal Industry is to double production by 1985 it must open 30 new 2,000,000 tons per year surface mines in the eastern states and 100 new 5,000,000 tons per year surface mines in the western states, in addition to major growth in underground mining. Major expansions in coal mining are also planned in other countries. Engineering geology can play an important part in coal mine development, operation and abandonment (Table I), and with the increasing scale of surface coal mining and the requirements of environmental legislation, it seems certain that engineering geology and geotechnics will play a growing role in surface coal mining.

Jan 1, 1976

By H. W. St. Clair

This study was undertaken to provide a more adequate knowledge of the chemistry of the sulfide volatilization process for recovery of tin from low-grade Bolivian ores. The investigation was partly supported by the Department of State under its program for scientific cooperation with South American republics. The results of this investigation demonstrate the conditions under which cassiterite (Sn02) may be converted to stannous sulfide by reaction with pyrite or sulfur vapor, Quantitative data are given on the rate of sulfidization and on the vapor pressure of stannous sulfide.

Jan 1, 1954

By R. P. Fischer

The Colorado Plateau region has been the principal domestic source of uranium, vanadium, and radium. The value of these commodities produced from the region through 1964 slightly exceeds $2 billion. Most of the deposits occur in streamlaid lenses of sandstone in the Chinle and Morrison Formations. The ore minerals below the zone of oxidation are low-valent oxides and silicates of uranium and vanadium; all of these, except the quite stable vanadium silicates, oxidize readily to a variety of high-valent uranium and vanadium minerals. The ore minerals partly replace fossil wood but mainly impregnate sandstone, typically forming tabular ore bodies that are nearly concordant to the bedding of the host rock. The deposits range in size from those containing only a few tons of ore to those containing more than 1 million tons. Stratigraphic, lithologic, and sedimentary structural factors obviously influenced the localization of these deposits, but igneous activity, hydrothermal mineralization, and tectonic structures show no similarly consistent influence on localization. The deposits are epigenetic, but the source of the ore metals, the nature of the ore-bearing solutions, and the time of ore emplacement are uncertain. A few uranium deposits in the region are dominantly discordant to bedding and occur in collapsed breccia pipes or along linear fractures. Their origins are also uncertain.

Jan 1, 1968

By Harold E. Marr

Energy dispersion X-ray analysis was evaluated for possible application in the secondary metals industries for the rapid analysis and identification of copper-base alloys. Laboratory investigations of standard brass and bronze samples indicate that X-ray methods are capable of separating standard alloys into 10 general classes with analytical times of less than 3 seconds per sample for clean, flat samples. A radioactive source of americium 241 with a secondary fluorescer was used as an excitation source, and a lithium-drifted silicon semiconductor detector was utilized for energy discrimination of X-rays.

Jan 1, 1974

By D. Bai, F. Hamad, S. Abraham

For the integrity of welded structures such as pipelines, the toughness of the heat-affected zones (HAZ) is an important property. This property is often specified in terms of Charpy V-notch (CVN) impact toughness and determined by the standard test method. An experimental study has been conducted in an industrial laboratory to measure the impact toughness of the coarse grain heat-affected zones (CGHAZ) of an X80 line pipe material. The field girth welding conditions in terms of heat input were simulated, together with special edge preparation to improve the targeted testing of the CGHAZ. The effect of toughness of the neighboring regions, in particular the weld metal, on measured impact toughness of the CGHAZ was investigated. The fracture paths of the CVN tested samples were examined by both optical and scanning electron microscopy. The deviation of segments of the fracture path into the weld metal was found to have a significant effect on the measured impact toughness of the CGHAZ.

Jan 1, 2005

By G. J. Simandl

"Since the 1980s, China has become the predominant producer of REEs. Recently, it introduced REE export quotas and this started a world-scale REE exploration rush. REE resources are concentrated in carbonatite-related deposits, peralkaline igneous rocks, pegmatites, REE ± P veins, ion adsorption clays, placers, and some deep ocean sediments. REEs could also be derived as a by-product of phosphate fertilizer, U processing, Ti-Zr-bearing placers, and exploitation of Olympic Dam-type sub-type of IOCG deposits. The ideal REE development target would be located in a politically stable jurisdiction such as Canada. REE grade and tonnage, mineralogy, and permissive metallurgy are some of the key technical factors that could be used to screen projects. INTRODUCTIONAccording to the International Union of Pure and Applied Chemistry (IUPAC), the term “rare earth elements” (REEs) encompasses yttrium (Y), scandium (Sc), and the lanthanide series: lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). This definition is used throughout this paper.REEs are subdivided into light (LREE) and heavy (HREE) categories. LREEs include, Sc, La, Ce, Pr, Nd, Sm, Eu, and Gd and HREE include Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y. Promethium (Pm) does not occur in nature. Concentrations of individual LREEs in the upper crust of the Earth are comparable to those of base metals. Even the least abundant REE (Lu) is about 200 times more abundant than gold.The production of REEs, reported in the form of oxides (REOs), for 2011 is estimated at 140 000 t (Figure 1a). Although high technology industries can substitute several REEs with other materials, these substitutes are typically more expensive or less effective than the REEs they replace. A number of countries, including the United States, consider several REEs essential for national security, their economy, and a general reduction in green house gas emissions. The forecasted demand for individual LREOs is much higher than that of HREOs (Figure 2). Dy, Eu, Tb, Nd, and Y are essential for the US economy and subject to predicted supply disruptions (U.S. Department of Energy, 2010)."

Jan 1, 2012