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An incremental-analysis-based stope design and cutoff grade calculation method was developed for an underground metal mine project. Traditional stope design methods are typically very time consuming and lack consistency and accuracy by manually drawing stope shapes. For quick reserve calculation and economic analysis, a new method named "3D incremental analysis based stope design" was created for mine-wide stope designs. The key idea of this method is to replace engineers' manual checking of each incremental ring with one calculation of all the rings, and to build the final stope shape with the maximum values. This process was realized through a 3D ring grid setup and proper naming conventions for rapid calculations. With this unique but practical method, multiple options for a mine design were completed within a short time before the final selection of optimal cutoff grade and best stope designs for the project.

Jan 1, 2012

By Jorge Ganoza

Dado que la metalurgia no es una ciencia nueva -en tanto que los conceptos utiilizados como propiedades geológicas, mineralización, procedimientos de extracción y recuperación de oro son practicados durante mucho tiempo, la variación actual de su nombre, no es determinante. En ese sentido, el presente texto señala algunos aspectos metalúrgicos del oro como: mineralogía de los depósitos de oro, las muestras geometalúrgicas para el programa de pruebas, mezclas de minerales, ley de oro y relaves de cianuración.

May 1, 2013

By Bjorge, Guy N.

MINING method improve through the gradual process of evolution and in 1340 there were no marked outstanding innovations. On the other hand refinements of detail and betterment: in equipment design continued to progress. Among the most important changes have been the increased application of trucks and highway equipment, including tractors and bull- dozers, to open-pit mining as exemplified by Phelps Dodge's Morenci operations; the Mesabi iron range; and the Tri-State district. Mass or bulk handling contributed its part underground with slurhers and conveyors at Consolidated Coppermines and slushers at Climax; and in open-pit mining. conveyors found increased use on the Mesabi range.

Jan 1, 1941

The system of keeping geological plans and sections for the Geco Mine at Manitouwadge, Ontario, is described. Special methods employed to save draughting time with-out sacrificing accuracy, such as the extensive use of black line prints, are discussed. The uses made of the plans and sections by the mine planning engineers in their designs of stopes, and by the blast-hole engineer in ~is preparation of blast-hole layouts, are noted. An unusual scheme for portraying the distribution of .copper, zinc and silver values within the ore zone is de-scribed. The method of estimating the grade of ore to be "blasted in each ring of blast holes is outlined, as is the method of estimating the annual ore reserves. The design of an effective but simple transparent geo-logical and mine development model, used as a display for -visitors, is discussed. A large-scale model used for the study of problems in geological structure is also de-scribed.

Jan 1, 1964

By R. G. Aspden

The cold rolling and annealing textures were studied for 3 pct Si-Fe grains initially (001) [hkl]. A concentration of (001) [loo] primaries were observed only in the annealing textures of crystals initially having [loo] within 8 deg of the rolling direction. Eke annealing textures of the (001) [I101 cold rolling textures were sensitive to the initial orientation of the grains. Single crystal data were used to explain the formation of (001) [loo] in poly-crystalline malerial. CUBE texture formation in 3 pet Si-Fe sheet occurs during the final high temperature anneal. Its formation is dependent on the proper distribution of (001) plane primaries with reference to the rolling direction&apos; and on the growth of these primaries by secondary recrystallization. The selective driving force for these primaries with (001) within 7 deg of rolling plane is derived from the difference in surface energy between the annealing atmosphere and the crystallographic planes exposed at the surface of the sheet.&apos;-= The alignment of [loo] directions of (001) secondaries with the rolling direction is required for optimum magnetic characteristics7 and is dependent on processing.&apos; A high degree of alignment has been observed when the final cold rolled texture has a strong (111) [ll2] type component3 and the normal grain growth texture prior to secondary recrystallization has components with a [loo] parallel to the rolling direction and planes from (001) to (110) parallel to the rolling plane.1,3,8,9 Generally, this (001) component is much weaker than the (110) component. The growth rate of (001) plane primaries to secondaries has been found to be independent of the orientation of the primaries with reference to the rolling direction, i.e., the secondaries have the same degree of alignment of [loo] directions with the rolling direction as the (001) primaries.&apos; Hence, the rolling and annealing textures of individual grains or single crystals are of interest in understanding the development of the (001) [loo] secondary recrystallization texture. (001) components have been observed in the annealing textures of cold rolled grains initially having a [loo] parallel to the rolling direction and an (001) rotated up to 30 deg from the rolling plane. Crystals initially near the (001) [loo] orientation when rolled under the influence of constraints imposed by neighboring grains form deformation bands and ro- tate in both directions toward (001) <110>.10,11 Deformation bands have been reported also for crystals initially with an (001) within 1 deg of the rolling plane and a [loo] within 1 deg of the rolling direction when rolled as a free single crystal.12 These crystals have weak recrystallization textures and contain near an (001) [loo] component.10-12 When near (001) [loo] crystals are rolled as free single crystals no deformation bands form and the crystals rotate by a single rotation toward (001) [110]. Recrystallization after a 70 pct cold reduction yielded near an (001) [loo] component13 and after a 90 pct cold reduction an (001) [I201 component." Crystals initially near (210) [001] had a texture after a reduction of 70 and 84 pct which was similar to the (111) [li2] but rotated 10 to 15 deg in the transverse direction. These crystals recrystallize to (210) [OOl] or (410) [001] and contain an (001) [loo] component.10,13 An (001) component has not been detected in the normal grain growth textures of other single crystals. Crystals initially having orientations between (110) [001] and (111) [ll2] have a cold rolled texture of principally (111) [ll2] .10>16 Other crystals with a [I101 parallel to the cross direction rotate to (111) [112] and/or (001) [110] stable end orientations. Crystals initially having from (001) [110] to (111) [lie] retain this orientation after cold rolling.15 The cold rolled textures having [I101 directions parallel to the rolling direction had components in the annealing textures related to the deformation textures by 25 to 30 deg rotations about common (1 10) poles. Cold rolled textures of the (111) (112) type recrys-tallized to (120) [001] or (110) [00l]. The purpose of the present work was to further the understanding of the alignment of [loo] directions of (001) secondaries with the rolling direction. The cold rolling and annealing textures of grains initially (001) [hkl] were studied. These data were applied to the formation of (001) [loo] by secondary recrystallization. PROCEDURES AND EXPERIMENTAL TECHNIQUES The (001) poles near the sheet normal and rolling direction are given in Fig. 1 for the 10 grains studied. Each of these grains was located in the center of a polycrystalline specimen approximately 25 mm wide and 50 mm long. The lower case lettered grains, a through dl were about 1.2 mm in diam and near the (001) [loo] orientation. Specimens containing these grains were from a commercial 3 pct Si-Fe alloy with the principle orientation of (110) [001] as obtained by impurity inhibition of growth with manganese sulfide inclusions.17,18 Upper case lettered grains, A through F, were about 6 mm in diam and had (001) planes near the rolling plane and [hkl] di-

Jan 1, 1963

By A. W. Fahrenwald

The purpose of screening is to separate a crushed or natural product into one or more products in which size of grain is constant, or within certain size limits. The ore dresser finds need for this operation in the laboratory, in the study of ore-dressing processes, and for various purposes in the plants. In the plant, for example, screens are employed in closed circuit with crushing devices such as rolls, and sometimes are used in closed circuit with ball mills. Screens are generally used to prepare jig feed where a sized feed is wanted. For any given sieve opening there is in any feed a certain percentage of grains that will pass through the sieve meshes only with difficulty and under favorable conditions. For example, cylindrical grains of length greater than the maximum dimension of the sieve mesh and of diameter less than the sieve opening pass the sieve only when the long axis of the grain is normal or nearly normal to the sieve. Whether such grains should actually be in the through&apos;s or the oversize of a screening operation--considered from the point of view of the subsequent treatment of the grains--can not be said. The grains that pass the sieve opening in a screening process only under-favorable conditions have been named "difficult" grains by R. K. Warner.4 In many ore-dressing flow-sheets it probably matters little whether these difficult grains show up in the screen through&apos;s or oversize. The main objection to them is that they are sieve-blinding.

Jan 1, 1929

By Daniel Augusto Ferro

Devido crescente necessidade de elevação dos níveis de conformação em peças estampadas, existe uma demanda cada vez maior em ligas e processos diversificados que atendam as variadas exigências do setor de produtos estampados e posteriormente tratados termicamente para aumento de dureza. Desse modo desenvolveu-se a liga C80M (modificada), que é uma variante da liga C80U especificada na norma DIN EN ISO 4957 porém com adição de Cromo, entretanto a liga C80M ainda é pouco estudada e pouca informação técnica se tem a seu respeito. Com a finalidade de melhor conhecimento técnico dessa liga, foram conduzidos estudos de caracterização em amostras laminadas a quente e após processo de esferoidização posteriormente sendo revestidas com fosfato de zinco. Foram realizados estudos de composição química, microestrutura e propriedades mecânicas, além de levantamento da curva CLC através do método Nakazima em amostras com e sem revestimento de fosfato. Através dos resultados parciais encontrados, foi possível definir o lado da curva CLC relacionado ao estiramento da chapa bem como comparar o deslocamento e a força do punção no teste Nakazima conformando-se amostras esferoidizadas sem e com revestimento de fosfato.

Jul 30, 2018

By Sivan Iswaran, Will McLean

This paper details a 2MLD ion exchange water treatment plant which selectively removes arsenic, antimony, iron, hardness, and sulphate from mining water; designed to meet environmental quality indicators such as sulphates. The client, Fosterville Gold Mine Pty Ltd, is owned by Kirkland Lake Gold and is one of the world’s highest grade gold mines. The site located near Melbourne, Australia had identified a risk of reduced mine water storage capacity due to surface run-off and increased sulphate rich dewatering of the underground mine at depth. Clean TeQ Water carried out the project management, process design, procurement, and commissioning for the plant, which was handed over in August 2020.

Sep 30, 2022

By D. E. Sullivan

The Minerals Availability Program of the Bureau of Mines conducts cost evaluations of current and potential mineral operations in the United States and foreign countries. The International Mining Cost Indexation System (IMCI) allows data of different time periods within a country to be updated to a common base year for analytical purposes. The IMCI comprises 12 factor cost indexes and an exchange rate series for 96 market economy countries, denominated in both local and U.S. currency. The IMCI for each country contains 12 time series indexes that measure the average annual rate of change in the cost of factor inputs to the mining industry within that country. Mining industry factor cost indexes include wages, plant and equipment, construction and mining materials, power and transportation, and other measures considered to comprise the majority of capital and operating costs. Cost data or proxies are collected in local currency. Index series within each country are constructed separately and indexed on a 1975 base year. The local currency index is converted to a U.S.-dollar-based currency index using an exchange ratio.

Jan 1, 1987

By D. Kumar, R. J. Sweigard, J. Silva

The Forestry Reclamation Approach (FRA) recommends that the upper 1.22 m (4 ft) of spoil material on reclaimed surfaces should be left as uncompacted as possible to facilitate efficient tree root growth. However, the main concerns about applying the FRA to steep slopes is that the upper 1.22 m (4 ft) of loose spoil material could cause instability. Successful application of the FRA on the flat and rolling surfaces precipitated this investigation. Details of a field investigation conducted at a steep-slope mine site are available in an earlier publication (Kumar and Sweigard, 2011). A total of 70 survey monuments were driven into the slope in a regular pattern to monitor any type of slope movement. Quarterly surveying of the monuments were done to quantify slope movement, either horizontally or vertically. The methodology developed in this research for field slope movement monitoring was validated using computer model results. Analytical models based on the limit equilibrium method (LEM) and numerical models based on the finite element method (FEM) were developed for slope stability analysis. The LEM analysis was done using the Geo-Slope/W program following the simplified Bishop method. However, numerical models were developed using the PLAXIS computer program following the Mohr’s Coulomb failure criterion and strength reduction technique. The slope stability analysis was performed for two different scenarios: first with the top 1.22 m (4 ft) of loose graded spoil material and second without top loose graded spoil material. Finally, the field investigation results were compared with stability analysis results. Both of these approaches showed that application of the FRA on steep slopes is not causing any significant instability problems, due to 1.22 m (4 ft) loose graded spoil that would not exist otherwise for overly steepened slopes.

Jan 1, 2013

The oxidation of zinc vapour plays a very important part in the operation of the Imperial Smelting Process. The kinetics of the reoxidation of zinc vapour by carbon dioxide and water vapour onto quartz and zinc oxide substrates is qualitatively understood and this pertains to the conditions found as the gases are being transferred from the furnace to the splash condenser. However, re-oxidation also occurs in the shaft of the furnace where the solid substrates are sinter and metallurgical coke. It was found that there was a threefold increase in the rate of oxidation on sinter, compared to quartz and a 30 to 300 increase in rate on the coke. This was attributed to the high surface area offered by these materials.

Jan 1, 2003

The oxidation of zinc vapour plays a very important part in the operation of the Imperial Smelting Process. The kinetics of the reoxidation of zinc vapour by carbon dioxide and water vapour onto quartz and zinc oxide substrates is qualitatively understood and this pertains to the conditions found as the gases are being transferred from the furnace to the splash condenser. However, re-oxidation also occurs in the shaft of the furnace where the solid substrates are sinter and metallurgical coke. It was found that there was a threefold increase in the rate of oxidation on sinter, compared to quartz and a 30 to 300 increase in rate on the coke. This was attributed to the high surface area offered by these materials.

Jan 1, 2003

By D Brown, Z Tabor

Projects must be flexible to account for the rapid development of new technologies and changing stakeholder expectations. Coupled with calls for bleeding-edge solutions, customers, shareholders, and regulators demand robust, safe products and systems-of-systems. Developing and integrating these solutions is becoming increasingly complex and maintaining the flexibility required to ‘pivot’ to effective solutions can be a serious challenge. The necessary flexibility is fundamental to the Agile ethos, and this family of methodologies therefore offers a potential solution to this challenge (Beedle et al, 2001). These have traditionally been delivered with systems engineering applied through a Waterfall methodology. Agile Systems Engineering combines both approaches and presents a means to achieve these goals without compromising flexibility, quality or safety. A robust methodology for the application of Agile Systems Engineering is required to enhance practical outcomes and reduce risk for real-world mining projects.

Sep 1, 2024

By D Will

RedrossThe Redross orebody averages 1 m wide, has a strike of 50 - 350 m, dips at 55° and has a basalt footwall and an ultramafic hanging wall. The most successful and innovative aspects of mining Redross were:•ore development innovations, 90 per cent of development was split fired with a shanty back profile to enable larger and more productive equipment to be used and resulted in higher development grades, improved project payback time and improved ore recovery;•hand held stoping using a multiple level, bottom up ‘V’ shaped hand held stoping method that allowed mining on multiple levels with hand held productivities between 50 and 90 tonnes per shift;•the use of 1 m cement pillars and 7 m high crown pillars were used to create multiple mining areas that enabled high overall production rates from hand held mining this orebody; and•the use of vertical cement pillars to enable hand held mining of adjacent stopes without leaving ore pillars.MarinersThe Mariners orebody averages 3 m wide, has a strike length of 50 - 250 m and dips at 50° with a basalt footwall and poor ultramafic hanging wall. The most successful innovative ideas of re-opening Mariners were:•Dewatering the existing mine workings utilising ‘oilfield’ technology by installing a long submersible pump in on existing pump rising main. This enabled the mine to be dewatered at rates up to 100l/ sec and helped overcome the 45 to 55 L/s inflows.•Overcoming the technical problems associated with Mining N07 ore blocks which had severely deteriorated from being underwater for five years by using reverse firing techniques to improve extraction rates and reduce dilution.•Mass firing a large mining block in the N08 with minimal void space because of deteriorating ground conditions.•Use of a longhole version of the Redross hand held mining method to achieve 100 per cent extraction of the N09 higher grade lenses.

Mar 21, 2011

By S. Mathieu, R. Mennillod-Blondin, P. Cousin, N. Valle, H. Bouzahzah, P. Marion

The gold deposit of the Lapa mine has a complex mineralogical gold state with coarse and fine native gold, aurostibite and submicroscopic gold within arsenopyrite. A specific mineralogical characterization of the refractory fraction was conducted combining various techniques such as optical microscopy, electron microscopy, electron microprobe and secondary ion mass spectrometry. In parallel, the mineral processing behaviour and the recovery of the refractory gold were studied by pressure oxidation and cyanide leaching. This paper presents the mineralogical methodology developed to characterize the refractory gold distribution within arsenopyrite. These results are presented and interpreted in order to plot gold recovery versus sulphide oxidation. The comparison of the metallurgical behaviour yields predicted from the mineralogical data and the one calculated from leaching tests shows a good agreement and allows mineralogical explanations of the gold metallurgical behaviour.

Jan 1, 2011

By C. J. Chindgren

A refractory-lined, garage-type automobile incinerator with a natural gas afterburner for air pollution control was cooperatively constructed and tested by the Bureau of Mines and the Wasatch Metal & Salvage Co. in Salt Lake City, Utah. The incinerator is capable of relatively smokeless burning of 32 to 60 cars per day, dependent on the degree to which the cars are stripped prior to incineration. Preliminary burning campaigns indicate the cost of incineration to be approximately $2.75 per car.

Jan 1, 1970

By R. D. Lrwin, W. M. Mullins, S. Venugopa, J. C. Malas

"Physical models for acoustic emission (AE) are introduced and expressions are derived to predict AE activity from such parameters as applied stress, strain and strain-rate. These models are then incorporated into a visco-plastic finite-element simulation program, and the acoustic emission event rate generated during metal forming operations are predicted. Simulation results are presented for upsetting operations on a typical C-Mn type steel for various friction and die geometry conditions. The AE model predictions compare well with the limited available experimental results reported in the literature and demonstrate that AE signatures can be reliably simulated. The signatures predicted for metal forging are fairly insensitive to processing parameter changes. This suggests that AE event rate monitoring may not be well suited to process monitoring for forging. However, the size of the features is conjectured to influence the frequency content of the AE signals. Thus, since current simulations include only the ability to predict the number of events for a set of processing conditions, future work is required to simulate the duration and magnitude of acoustic events. Fourier analysis techniques may then be applied to investigate correlation with microstructural features.IntroductionThe open loop control system method for deformation processing design, as described by Malas et al. [1 ], consists of several steps in series to achieve the final design. The first step uses microstructure development models to determine the optimum deformation path to achieve the desired final microstructure. The second step, the process model, calculates the processing parameters required to achieve this deformation path. Finally, the metal-working system uses the required processing parameters to produce the part. Figure 1 shows this in block diagram form"

Jan 1, 1997

By J. E. Amadi-Echendu, F. Stober, J. Ndlovu, L. R. Nelson

The Polokwane Smelter Complex (PSC) relies on a single 68MW high-intensity six-in-line furnace to smelt a planned 650 000 t/a dry concentrate to produce a platinum group metals (PGM)-bearing matte. As typical of a greenfields venture, considerable attention was paid to the project development and implementation stages of design, engineering, construction and commissioning. Somewhat unusual though, was the role of a dedicated multi-disciplinary "Operational Readiness" and support team, comprising the owners team and specialists from the furnace designer, HATCH, to effect a safe and rapid ramp-up to the design smelter capacity of 68MW. The challenges encountered in developing an effective partnership will be discussed. The modus operandi and roles of the "Operational Readiness" team during the design, procurement, construction and commissioning stages as well as that of the operational support team within the overall ramp-up objective will be presented. The "Operational Readiness" team was responsible for:

Jan 1, 2005

By D. H. Ryan, J. T. Graham, A. Navarra, J. A. Finch, S. Somot

Pyrrhotite (Po) is widely considered to be the most significant mineral in the self-heating of sulphides. It is therefore desirable to determine the amount of Po in mineral samples. This is commonly accomplished through x-ray diffraction (XRD) or quantitative evaluation of materials by scanning electron microscopy (QEM-SEM). This paper introduces another quantitative method based on Mossbauer analysis that requires limited sample preparation and has the additional potential to detect the sulphur/iron ratio within Po. The technique is explored using pentlandite/pyrrhotite mixtures.

Jan 1, 2009

By W. G. Pariseau

Joints may be taken into account when using numerical modeling as an aid to mine design by embedding joints in the model. When using the popular finite element method, say UT3PC, a pre-analysis step is necessary, Step 0. This step is for the computation of equivalent properties of a representative elementary volume of jointed rock (REV) in the model. This Step 0 is taken before Steps 1, 2 and 3 for specification of a rock properties file, generation of the mesh, and model analysis are taken. A brief explanation of equivalent properties and several examples aid in explaining the details of Step 0. Focus is on procedures, input files, and output to show ease of computation. Theoretical details are relegated to references (e.g. Pariseau 2022). Comparisons of safety factor distributions about example mine excavations with direct scaling from mine observations then offer some insights concerning equivalent properties, especially strengths.

Feb 1, 2023