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By L. C. Stone, J. C. Parr, T. N. Anderson, D. Metcalf

An increase in the importance of low-grade materials as sources of gold and silver has led to the need for improved analytical methods on leach solutions, ores and various effluents, residues, and in-process streams. These are required by plant operators as guides to process control and for accounting pldrposes. Atomic absorption spectrophotometry (AAS) and AAS preceded by pre- concentration have been applied successfully to resolve many such problems. However, AAS is no panacea and imprecision or loss of accuracy can result if adequate precautions are not taken to prevent losses and eliminate interferences. The recent methods are discussed together with methods for overcoming difficulties. Comparisons with more classical analytical techniques are also given.

Jan 1, 1981

By C. Bachmann, M. J. Laurila, A. J. Widenman, A. Klein

Elemental analysis of slurry streams using X-ray fluorescence (XRF) has long been employed. However, detector technology has limited the application of XRF devices. Using detector technology employed on NASA's Mars Pathfinder to analyze soil samples, Process Control, Inc. has developed an on-line analyzer to mount on a sampling system. The prototype XRF elemental analyzer was installed at Detroit Edison's Monroe Power Plant in January, 1998 and has been employed to monitor feedstock quality. A slurry system has been developed for flotation control. This paper describes the testing of the analyzer using the new, draft ISO standard for evaluating the performance of online analyzers (ISO/DIS15239).

Jan 1, 1999

By François Girard

La zone 1 de la mine Doyon (zone altérée), se situe à l?extrémité sud de la mine et est constituée d?une série de veines étroites à fort pendage et ayant des épontes de très faible résistance. Les épontes supérieure et inférieure ont des valeurs de RQD variant de 0 à 20 lors que les valeurs de RQD de la zone minéralisée se situent entre 20 et 40. Le minerai de la zone 1 s?étend sur environ 300 m de long et sur 900 m de profondeur avec des épaisseurs variant entre 2 et 15 m. Des méthodes de minage long-trous y sont utilisées avec des accès longitudinaux ou transverses selon l?épaisseur de la zone minéralisée. L?exploitation de la zone 1 a débuté en 1991 et plus de 1,7 millions de tonnes auront été extraites à la fin 2008. Plusieurs techniques y ont été testées que ce soit au niveau du développement ou du minage afin d?améliorer la sécurité des travailleurs, de réduire la dilution des chantiers et d?en augmenter la récupération. Différentes modifications ont été apportées aux dimensions et orientations des galeries, aux patrons de forage, aux techniques de sautages, au support de terrain, à la séquence de minage et aux méthodes de remblayage. Le texte suivant élabore sur plusieurs approches utilisées lors du minage de la zone 1.

Feb 1, 2008

The aim of this investigation was to study the influence that varying production rates have on iron sinter quality. This was done by performing sinter pot tests at different pressure drops over the sinter bed, namely 11 kPa and 15 kPa (for 500 mm total bed depths). During each of the sintering processes temperature-time profiles were recorded of the top, middle and bottom layers of the sinter bed. On completion of the sinter process the sinter cakes were divided into top, middle and bottom layers. The physical properties of each layer were subsequently characterized by performing a tumbler test and a sieve analysis. A comprehensive mineralogical study was also conducted on each layer. This study revealed that sinters of similar cold strength could be produced under the examined production rates. However, a higher production rate was accompanied by an increased amount of fines. The cold strengths of both sinters significantly increased from the top layer to the bottom layer of the sinter bed. This strength variation is not related in any simple way to the phase composition. Keywords: Sinter, sinter bed, production rate, phase composition, cold strength, tumbler index, sieve analysis, temperature-time profile

Jan 1, 2003

By B C. Povey, K Lagutin, M Mryasov, V Noll

The current Stoilensky magnetite concentrator comprises a three-stage crushing circuit followed by three stages of ball milling, grinding and concentration to produce a magnetite concentrate with 66.5% iron (Fe). The plant is built in four lines, three lines having four mills and one line with five mills, to treat 32 Mt/y of ore and produce 13.9 Mt/y of concentrate.NLMK, the owner, is Russia’s third largest steel maker and while the ore from the Stoilensky Mining and Beneficiation Plant (SGOK) provides the bulk of their supply, they still must buy ore from external sources at world prices. A decision was taken to expand the SGOK operation to supply all the NLMK concentrate, including the production of pellets.To commence the expansion, high pressure grinding rolls (HPGRs) were introduced as a fourth stage of crushing ahead of the first ball mill. This was a relatively low capital cost expansion and increased production by 12 to 15%, the cost being much less than an additional grinding line. The importance of this development was that earlier introductions of HPGRs in Russia had presented several problems so there was some reluctance to the initial concept. The even greater significance was that nearly every magnetite plant in Russia had a three-stage crushing circuit so the successful introduction of HPGRs was of interest to many operators.The design was developed by a team, consisting of Worley Parson, Mineralconsult and PiterGORproject (PGP), for the first four units to fit inside existing building structures. The first two units were commissioned in March 2016 and the next two units in May 2016, and production improved by over 12%. The design of the installation of the final four units is in progress and the installation is expected in late 2017.CITATION:Povey, B C, Noll, V, Lagutin, K and Mryasov, M, 2017. Introducing HPGR quaternary crushers in a Russian magnetite operation – challenges and solutions, in Proceedings MetPlant 2017, pp 84–100 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

By S C. Dominy

Various styles of gold mineralisation pose problems during sampling because of their complex gold grade distribution and presence of coarse gold. Effective sampling and sample preparation forms the basis of resource estimates. The design of a sampling and assaying protocol must be based on a thorough understanding of the mineralisation in question, which should include consideration of gold particle size and mass distribution. The proportion of coarse gold within samples has a profound effect on the requirements for sample preparation and assaying. Choice of preparation procedure and assay type is of critical importance if sampling errors are to be minimised. Traditional fire assays, using small charge sizes, often understate assays gained from large charge sizes and techniques such as screen fire assay and LeachWELL. Proper application of the Theory of Sampling reduces errors during collection, preparation and assaying. A quality control/quality assurance program must be implemented and critically assessed. A case study from the Ballarat mine is presented, which is characterised by substantial quantities of coarse-gold hosted in quartz veins. Diamond core drilling is the key input into resource delineation. A number of different sampling and assay options have been trialled over the recent project history. The current sampling protocol utilises whole drill core, using LeachWELL assays after logging and photography.CITATION:Dominy, S C, 2017. Sampling coarse gold-bearing mineralisation – developing effective protocols and a case study from the Ballarat mine, Australia, in Proceedings Eighth World Conference on Sampling and Blending , pp 71–84 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By S. Roy

Soft laminated iron ore (SLO) having a higher hematite content and Martite goethite iron ore (MGO) having a higher goethite content were subjected to detailed characterization and beneficiation. The present research was designed to investigate if these abundant, low-grade ores can be enriched adequately using standard industry techniques. No significant enrichment of the ores using jigging operation on the coarse (-3,200 +595 mm) size fraction could be achieved. Good liberation was only attained in the 150 to 300 mm particle size range in both cases. Desliming enriches the ground ores significantly. The effect of the feed size on the separation efficiencies of the ground ores were studied using flowing-film concentration on a Wilfley table. Better enrichment is obtained in the case of 150-mm sized feed by tabling. The grade of SLO is improved from 56.14% to 66.51% Fe, while the Fe content of MGO is enriched from 55.16% to 65.83%. Substantial rejection of alumina and silica is also achieved. Due to the friable nature of MGO and the higher goethite content in it, the loss of Fe in the form of ultrafines is greater in this case compared to that of SLO.

Jan 1, 2009

By William P. Shinn

IT seems proper to present in the Transactions of the Institute, from time to time, formal record of the advances made in the arts and sciences to which our organization is devoted-milestones in the highway of progress-from which our successors may measure what they in their turn have gained. The admirable address of the Hon. Abram S. Hewitt, then president elect of the Institute, on "A Century of Mining and Metallurgy in the United States," read at the opening of the meeting held in this hall in June, 1876, forms a point of departure, and the conclusion of the eighth decade of the nineteenth century and the end of the first five years of our country's second century seem to offer a fitting time for again making up our record. The period since 1875 has been marked by a degree of activity in mining and metallurgical industry never before equalled in our history, while the progress made in the science and art has been, if possible, still more noticeable. Whether we consider the mining of iron, ore, and coal, or of the precious metals,-the advances made in smelting the former and in reducing the latter, the extraordinary increase in the production of Bessemer steel, or the science of Thomas and. Gilchrist, which makes the hitherto rejected phosphorus the corner-stone of success,-the past five years are alike memorable for the progress they have shown and to some of the most marked features of this progress I will now oriefly call your attention. It may be of interest in this connection to note the following figures, showing the growth of the population of the United-States during the last three decades :

Jan 1, 1881

The following paper describes the refining practice for the production of lead, silver and gold at the works of The Broken Hill Associated Smelters Pty. Ltd., Port Pirie, South Australia.The refinery is situated on the wharf frontage and is built parallel with it. The refinery occupies an area of approximately 3380 square yards. (Fig. 8)There are two buildings, one containing the softening and de-silverising sections, measuring 225 ft. x 57t ft., while the other building, which measures 225 ft. x 90 ft. covers the de-zincing, lead moulding, retorting, cupellation, and dore parting sections. (Fig. 1)The retorting, cupellation, and dore parting sections are completely isolated from the rest of the plant by strong small-mesh wire gratings welded to steel uprights. The dore parting plant and generator room are further isolated by a brick wall, built up to the roof. The two main buildings are steel structures, with outer walls and roof of "Robertson" corrugated sheeting; the side and end walls are open for some distance above the ground, and this, coupled with the high roof which is 50 ft. from ground level, ensures the free access of air and light. Conditions are such that operators work in a clear atmosphere.

Jan 1, 1937

By E. R. Maize

This report is the second of a series on roof movement in coal mines. The first (R. I. 3355)4/ dealt with convergence of roof and floor and movement of the surface accompanying and following extraction in a mechanized mine in which retreat of rib lines was rapid. The studies reported herein were made in a mine in which all the coal is loaded by hand, and movement of the rib lines was much slower in consequence. In choosing a site for this work, it was decided that the mine selected should have natural conditions akin to those of the first study and entirely different methods of working. To this end a cooperative agreement was made with the Crucible Fuel Co. through W. J. Whitaker, secretary, for conducting the work in the company's Crucible mine, operating in the Pittsburgh bed in Greene County, Pa. This paper gives an account of the methods used in the investigation, excerpts from the data obtained, and such generalizations as can be made.

Jan 1, 1939

By D. Nyungu

Despite observations of spalling and damage of mine excavation wall rock in the Bushveld Complex (BC) over the passage of time, there have been very few time-dependent or creep tests carried out in South Africa on rock, particularly on BC rock types. The research described in this paper deals with the investigation of stress and strain conditions influencing spalling of wall rock in BC mine excavations, and the influence of time on the tensile strength of several BC rock types. Time-dependent laboratory testing of BC rocks was carried out in indirect tension. The results show that the magnitude of the tensile strength of BC rock types is approximately 5% of their uniaxial compressive strength magnitudes. The average long-term uniaxial compressive strength of the BC rocks, interpreted from the axial stress-volumetric strain graphs, is 56% of the UCS value. The long-term tensile strength is shown to be less than 70% of the normal tensile strength. Extension strains at tensile strength failure ranged between 0.16 and 0.21 millistrain. Values corresponding with the long-term tensile strength are less than 70% of this range, namely, 0.11 to 0.15 millistrain. These results represent new knowledge, since such rock testing and analysis does not appear to have been carried out previously on BC rock types. Elastic numerical modelling was carried out to illustrate the extents of tensile stress zones and extension zones around of typical BC mine excavations. The models showed that large zones of extension strain can occur around BC excavations, and that the magnitudes of the extension strain can substantially exceed the critical values determined from the laboratory testing. The implication of this is that there are substantial zones surrounding BC mine excavations that will be prone to time-dependent spalling conditions and perhaps more significant failure.

Jan 1, 2014

The dissolution of gold in cyanide has been studied, using both chemical and electrochemical techniques. The electro-chemical studies have confirmed that gold may become passive in cyanide solution if its potential becomes more positive than -O· 5 V v. saturated calomel electrode (S.C.E.). The results of the conventional solution rate tests suggest that, although the solution rate is controlled by the rate of diffusion of oxygen at low oxygen and agitation levels, when these are increased the gold may become passive and its solution rate approach a steady value, or even decrease with increasing oxygen level. The passivity of gold has been shown to be of importance in the solution of small spheres of this metal, and in the extraction of gold from a calcined auriferous pyrite concentrate.INTRODUCTIONAlthough it has been appreciated for many years (McLaurin, 1893, 1895) that dissolved oxygen is a necessary adjunct to the solution of gold by the cyanide process, attempts to quantitatively assess its effect have led to conflicting results. For example, Barsky, Swainson, and Hedley (1934) reported that an increase in oxygen concentration improved the solution rate, but Beyers (1936) claimed that such an increase would reduce the rate at which the gold dissolved.By using an electrochemical approach Kudryk and Kellogg (1954) showed that the diffusion rate of either the cyanide or the oxygen was a controlling factor, and that, if the mole ratio of cyanide to oxygen concentration was greater than 10, the solution rate was proportional to oxygen concentration.These results, although they represent some of the most careful work available, were in direct contradiction to the findings of Mills (1951), who found that gold may become passive in cyanide solution, with a resultant decrease in solution rate.

Jan 1, 1963

By G. Deschênes

The Eleonore property (James Bay district of Northern Québec), owned by Goldcorp, hosts gold within stockworks of quartz-tourmaline-arsenopyrite veins and veinlets contained within microcline (potassic alteration) and brown tourmaline replacement zones. The preliminary investigation to recover gold from drill core samples showed that flotation followed ultrafine grinding and cyanidation is the preferred option. Ultrafine grinding is used to liberate gold finely disseminated in sulphides. The flotation concentrate used in the investigation had a P80 of 11 microns and contained 75.5 g/t Au, 5.0 g/t Ag, 10.3% S, 0.07% Cu and traces of antimony (0.03%). The mineralogical characterization showed the presence of 65% gangue minerals, 23% pyrrhotite (hexagonal), 9.6% arsenopyrite, 2.2% pyrite and 0.08% chalcopyrite with trace amounts of galena (0.05%) and sphalerite (0.03%). Gold was in the form of native gold and electrum. A straight cyanidation conducted at pH 11.0, DO of 3-5 ppm, 2000 ppm NaCN, 20 C 72 hours extracted 97.0% Au and consumed 31.5 kg/t NaCN. The equilibrium was reached within 24 hours. Increasing the dissolved oxygen to 16 ppm reduced the consumption of cyanide to 22.0 kg/t with 96.7% Au extraction. A 16-h pretreatment with 2.0 kg/t lead nitrate, followed by a 24-h cyanidation reduced the cyanide consumption to 6.0 kg/t with a gold extraction of 97.5%. Increasing the lead nitrate addition to 6.0 kg/t reduced the cyanide consumption to 1.2 kg/t by passivating the surface of pyrrhotite. The gold extraction remained at 97.0%. It was possible to decrease the concentration of cyanide to 800 ppm NaCN without compromising gold extraction. The associated cyanide consumption was 1.2 kg/t NaCN. The passivation of gold grains was an issue when the cyanide concentration was decreased to 550 ppm NaCN. The gold extraction decreased to 92.2%. The average lime addition for all the tests was 7.4 kg/t and the average silver extraction was 80%. Efficient cyanidation of an ultrafine sulphide concentrate with only 800 ppm NaCN represents an advance in leaching of ultrafine sulphide concentrates.

Jan 1, 2013

The uptake of nickel into the lattice of pyrrhotite, Fe1 _1J S was studied experimentally in the temperature range 200°C to 760°C. Nickel from both aqueous solutions and salt melts diffuses rapidly into the sulphidelattice with an accompanying release of iron into the solution or melt. The rate of uptake of nickel and its diffusion into the sulphide lattice were followed by optical microscopy and by analysis with an electron probe microanalyser. Some geological consequences of this phenomenon affecting the distribution of nickel in rocks associated with nickel-iron sulphide ores are discussed.

Jan 1, 1972

By E. R. Maize

This report is t e second of s series on roof movement in coal mines. The first (R. I. 3355)4/ dealt with convergence of roof and floor and movement of the surface accompanying and following extraction in a mechanized mine in which retreat of rib lines was rapid. The studies reported herein were made in a mine in which all the coal is loaded by hand, and movement of the rib lines was much slower in consequence. In choosing a site for this work, it was decided that the mine selected should have natural conditions akin to those of the first study and entirely different methods of working. To this end a cooperative agreement was made with the Crucible Fuel Co. through W. J. Whitaker, secretary, for conducting the work in the company?s Crucible mine, operating in the Pittsburgh bed in Greene County, Pa, This paper gives an account of the methods used in the investigation, excerpts from the data obtained, and such generalizations as can be made.

Jan 1, 1939

By Damon P. Vandermaat

Coupon testing allows for the rapid understanding of a material?s likely behavior in service conditions, allowing engineers and operators to make informed decisions about the likely service-life of parts when subjected to field conditions. Bend testing has been identified as the best approach for exploring rock bolt susceptibility to stress corrosion cracking (SCC) in underground mining. The bend test specimens used were 2?3 mm thick slivers of steel, cut from the outer edge of a rock bolt. For the specimens, 1350 grade steel was chosen due to its wide use in the industry. The jigs themselves are small assemblies made of stainless steel that are capable of imparting a bending load on the specimens. The jigs were installed at a coal mine located in the Western Coals West of Sydney, Australia, in such a way as to expose the test specimen to water dripping from the mine roof. It is expected that this approach will yield results pointing to the likely SCC mechanisms affecting the service life of rock bolts, as well as demonstrate the jigs? usefulness as an early warning system for SCC. Furthermore, the coupon tests will be correlated against the results of large-scale laboratory tests.

Jan 1, 2012

By A. K. Raji, E. F. Orumwense, M. O. Ojumu

The Fourth Industrial Revolution has driven significant advancements in autonomous robotic systems, particularly in subsea exploration and offshore mineral dredging. This review examines the latest developments in electrically powered quadrotor-track subsea robotic crawlers, highlighting their potential to enhance efficiency, mobility, and adaptability in challenging underwater environments. The integration of advanced automation, artificial intelligence, and real-time control systems has paved the way for more effective robotic solutions in offshore mining. This study explores the dynamic performance of hydraulic crawlers to quadrotortrack robotic dredgers, focusing on their propulsion, navigation, and stability under high hydrodynamic conditions. By leveraging state-of-the-art technologies such as lithium-ion battery power systems, intelligent microprocessors, and sensor-based control mechanisms, these robotic crawlers offer a promising alternative to conventional subsea excavation methods. Furthermore, the review analyses recent experimental and simulation-based studies that assess the feasibility and performance of these systems in real-world applications. The findings of this review provide valuable insights into the role of 4IR in transforming subsea robotics for offshore mineral dredging. By addressing existing limitations and identifying key technological advancements, this study contributes to the ongoing development of nextgeneration robotic systems capable of operating efficiently in extreme underwater conditions

Jan 30, 2026

By William J. Rothschild

Ground water at construction sites can be controlled by properly placed wellpoint dewatering systems. Care must be taken in planning cofferdams to have adequate space for and access to pumps, headers and the points. A most important part of dewatering is protection of adjacent structures from movement. A checklist gives items to consider in bidding.

Jan 1, 1984

By R. Heath Forbes

The route of a new, 4-mile long, electrical transmission line passed through residential neighborhoods and commercial areas of a small town in the South Carolina Coastal Plain. The new line consisted of 54 new poles and a one-mile underground section. Most of the new poles were constructed within 50 ft of existing structures, and in some cases, within 8 ft to 20 ft. A widely-space subsurface exploration consisting of 20 cone penetration test soundings indicated the subsurface conditions along the alignment generally consisted of saturated, loose to medium dense, fine slightly silty to silty sand. The pole foundations consisted of 20 to 30 ft long, prefabricated ?caissons? (essentially an open-end pipe pile with a prefabricated connection system at the top) with diameters of 28 to 56 inches. The steel caissons were installed with vibratory pile hammers. To help prevent damage and defend against possible allegations from nearby property owners, vibration and settlement monitoring was performed during all foundation installation activities. Limited structural condition assessments were also performed before and after foundation installation. For 53 of the 54 foundations, the ground vibrations recorded at distances coincident with the nearest structure locations ranged from 0.05 inches per second to 1.46 inches per second. With consideration of the dominant frequency, the majority of these values were below the commonly used USBM vibration limits. For a foundation installation that was only 8 ft from the nearest structure, a peak particle velocity of 3.06 inches per second was recorded, which exceeded the USBM limits. For all cases, the measured ground surface settlement was negligible (i.e., less than ¾ inch). Several spurious claims alleging vibration-induced damage were made, but the monitoring program provided an adequate defense. One claim involving artwork that fell to the floor during foundation installation at a distance of 8 ft from the house was deemed legitimate.

Jan 1, 2011

Low Zinc Prices Close Alcoa Mine Alcoa Mining Co., announced that it will suspend operations at its Hutson mine, near Salem, Ky., because of low zinc prices, January 15. The Aluminum Co. of America subsidiary announced that the low market has made zinc mining un- profitable. About 70 men were employed at the mine, with a production of about 5000 tons of zinc annually. Alcoa said the shutdown would not affect other company operations, with most of the men at Hutson absorbed in the mining firm's fluorspar operations in the same area.

Jan 2, 1953