Search Documents

By L. B. Hales

December 3, 1972, James Wm. White presented the results of an instrumentation and process control survey which was sponsored by the Anaconda Company at the annual Tucson Subsection AIME meeting.(1) Twenty-six responses were obtained from questionnaires sent to 48 operating plants throughout the world. The survey results were discouraging in that there were more failures and problems than examples of success. The following quotes are taken from the text of the paper. "We run our mill by the seat of our pants." 'If these blue sky Ph.D.'s (in the instruments and controls area within research) had some operating experience they wouldn't make a lot of the suggestions they do."

Jan 1, 1981

By T. M. Barczak

This U.S. Bureau of Mines report investigates shield mechanics and component stress development in a two-legged longwall shield for unsymmetric canopy and base contact configurations. Previous studies analyzed shield behavior for symmetric contact configurations. The goals of these efforts are to improve longwall support selection and design. This study provides vital information that will help develop improved procedures for performance testing of longwall supports and will benefit future research to improve support design through stress optimization and evaluation of failure mechanisms. Combinations of six canopy (three symmetric and three unsymmetric) and six base (four symmetric and two unsymmetric) contacts provided a total of 36 configurations for evaluation. Of these 36 configurations, 10 were eliminated because of fixture limitations or shield instability. Controlled vertical and horizontal displacements were applied by the Bureau's mine roof simulator to the remaining 26 configurations. Component responses were determined from pressure transducer and strain gage instrumentation in order to identify contact configurations and boundary displacements that produced maximum loading in each of the support components. This report describes these test results and provides conclusions relevant to critical contact configurations for performance testing of longwall supports.

Jan 1, 1990

By Andrew Campbell, Michael Reed

"WorleyParsons has used Discrete Event Simulation methods in conjunction with more traditional process models to assess the performance of copper smelting operations. This work was performed to determine the plant capacities and suitability of proposed debottlenecking options including accounting for the planned and unplanned (breakdowns) shutdowns in the various parts of the plant and supply chain. This paper outlines the methods used along with demonstrating the benefits of selecting a feasible option and minimizing capital and operating costs.IntroductionTraditionally for de bottlenecking studies of smelters and other process plants, a mass balance is performed based on continuous operating rates and expected operating hours. Smelters have several points of failure that will restrict, if not take the entire plant offline. By using a more detailed model, validated against plant experience, bottlenecks can be demonstrated and strategies to remove them to increase plant availability and economic.The modeling simulates the plant performance in real time, and by performing enough simulation the expected long run performance of the plant can be estimated. The models have been built using ExtendSim which is a powerful Discrete Event Simulation software package that is ideally suited to the batch and semi-batch processes and events that occur within smelter operating environments. The value of performing this work is that the operational performance of the plant can be assessed ensuring production targets are met, without using excessive capital outlay."

Jan 1, 2013

By S Oliver, D Willingham

"Although a resource model is central to the mineral resource value estimation process (Glacken and Snowden, 2001), creating it is a labour intensive task and in the end it is a limited representation of the actual orebody. Creating this resource model is a labour intensive task that requires inputs from geology, mining, metallurgical and commercial disciplines. It requires thousands of samples from hundreds of drill holes to be verified, grouped in geological domain, interpolated and then valued. Even after all this effort, a model is only an estimation; therefore further significant effort has gone into quantifying uncertainty in the model and subsequently risk around any value estimates derived from the model. Further risks to model quality are introduced through poorly conditioned data or incorrect assumptions.This paper proposes the application of machine learning to automate the resource model development. Machine learning is applied to the traditionally manual tasks of geological formation, domain identification and validation of the block model mineralogy. Through automation the resource estimation process can be accelerated, allowing more drill holes or a larger resource body to be processed in a given time frame, or allowing the process to be more agile to changes in input data and assumptions. A case study based on drill hole data from a Western Australian iron ore deposit (Government of Western Australia, Department of Mines and Petroleum, 2015) is used to demonstrate the application of machine learning in this process.CITATION:Oliver, S and Willingham, D, 2016. Maximise Orebody Value through the Automation of Resource Model Development Using Machine Learning, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 295–302 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By C. M. Wright

Siendo la veta principal San Cristóbal, una de las estructuras que atraviesan el Anticlinal Chumpe en la provincia de Yauli, su explotación ha sido limitada a las rocas volcánicas y filitas en el flanco sur-oeste del anticlinal. Por tal motivo, el texto señala que el análisis de la distribución de los metales y minerales dentro de la veta, revela un zoneamiento horizontal bien definido, que es compatible con el origen de las soluciones hidrotermales en el centro del anticlinal. Asimismo, este estudio cuantitativo determina las características de las partes ricas de la veta, trazando líneas de contornos de los cuatro tipos de metal en secciones longitudinales, como los controles de la distribución de metal y relaciona las áreas ricas de la veta con su medio geológico. De otro lado, en San Cristóbal, la distribución del metal presenta una característica zonal donde la paragénesis y el zoneamiento están íntimamente relacionados. Concluyéndose que con la aplicación de los resultados de este estudio, se permitirá una mejor exploración y desarrollo de las áreas ricas de la Veta Principal San Cristóbal y se proporcionará una guía útil para la exploración y desarrollo de vetas paralelas en esta área.

Aug 20, 1963

By Luis Herrera, Luis Huamán

La minería peruana se distingue por sus estándares de clase mundial: la innovación es parte de su ADN. En ese contexto, Ferreyros y Caterpillar toman el encargo de participar en el proyecto cuprífero Quellaveco, de Anglo American, con una flota íntegramente autónoma de camiones mineros, los primeros en la historia del país. La búsqueda de la mejora de la seguridad, el incremento de la productividad y la optimización de la utilización de los equipos de acarreo son impulsores clave de la adopción de autonomía.

Sep 30, 2022

By Youngtak Ko

The northeastern Pacific shows the highest nodule abundance among the oceans in the world, and thus has been drawing international attention for deep-sea manganese nodule development. The objectives of this study are to construct database using geostatistics and geographic information system (GIS), to quantify rating value using probability and statistical methods, to suggest suitable sites for manganese nodule development, and to verify results using three statistical approaches. The copper and nickel contents of the nodules were determined by chemical analysis. Factors related to slope, aspect, water depth, and topography were obtained from multi-beam echo sounding data. The transparent layer thickness was determined using a sub-bottom profiler. The probability method was used to calculate each factor's rating, and the layers for different factors were summed to produce the development potential index (DPI). Result maps were constructed for manganese nodules development. The distribution pattern of DPI showed to be controlled of nodule abundance and metal contents. Verification was performed by comparing the results with sampling data in three ways: success and prediction rate, linear regression, and test of independence.

Sep 14, 2011

By H. Bernstein

Grain coarsening tests were carried out on AI-4.5 pct Cu and AI-4.5 pct Si alloys. The effects of three variables, melt composition, pour temperature, and mold temperature, were determined. It was found that the macrostructure generally coarsened with increased pour and mold temperatures. Coarsening was extreme in the unrefined alloys but was retarded by the active grain refiners like titanium and columbium. The effect of boron was spectacular in suppressing coarsening tendencies. The results of the investigation support the carbide theory of nucleation as opposed to the peritectic theory. A REVIEW of prior work on the subject of grain refinement in the light metals indicated that, for the most part, it had been concerned with the positive effects of addition agents upon structure. This work produced various theories of refinement. Prominent among them were the peritectic theory and the transition element carbide theory. Certain inadequacies in the former theory appeared to be explained satisfactorily by the transition element carbide theory. In order to appraise these theories further, a study was undertaken of the permanence of grain refinement effects when subjected to thermal or chemical variations. It was considered that a study of this kind would be of practical value, since the light metals are exposed to thermal and chemical variations in the normal course of foundry operations. Accordingly, two alloys of commercial importance were selected for this investigation, the A1-Cu and A1-Si alloys. Experimental Procedure and Results Raw Materials: The base alloys, A1-Cu and A1-Si, were prepared from virgin aluminum and hardeners, induction melted, and pigged for remelting. The grain refiners, including titanium, columbium, zirconium, and boron, were added as master alloys. Analyses of the raw materials and base alloys are listed in Table I. Melting and Casting Practice: The metals were melted in clay-graphite crucibles in a Hevi-Duty pit-type resistance furnace, equipped with a Leeds and Northrup Micromax Recorder and Controller. After melt down of the base alloys, the additions were made. For each casting, approximately 80 grams of metal were poured into a preheated graphite mold held in a transite flask. The mold (Fig. 1) weighed 320 grams. To determine the effect of superheat upon structure, a set of melts was heated successively to four temperature levels, 705°, 775°, 845°, and 915°C, and test specimens were cast at each level. Prior to each pour, the furnace temperature was held constant for 20 min. Next, a set of melts was put through a superheat cycle and test specimens were cast at melt temperatures of 705" and 915°C successively. The crucibles then were cooled in air to 705°C as deter-mined by immersion thermocouple and additional test specimens were poured. The cooling interval was approximately 1 min. Another set of melts was furnace cooled with the cover slightly ajar and test specimens cast as before. The interval in this case was 15 to 20 min, varying with the superheat temperature. The mold temperature for all these tests was 400°C. To determine the effect of cooling rate without superheat upon structure, a set of melts was heated to 705°C, and castings were poured at mold temperatures of 205", 400°, and 540°C. An interval of 15 min elapsed between each pour. Mold temperatures were measured by a direct reading millivolt-meter, using a chromel-alumel thermocouple located at midwall thickness of the mold. To demonstrate the phenomenon of chemical coarsening, agents such as chromium and beryllium, which had acted as coarseners in a previous investigation,' were added to the A1-Cu alloy. Test speci-

Jan 1, 1955

By Jorge Díaz A

El presente texto revisa los métodos utilizados en las minas de tajo de abierto como son la perforación, disparo y seguridad y así mejorar los standars y el rendimiento futuro en la industria minera. Respecto al primer método empleado, se analizan los factores que afectan el rendimiento de brocas y cómo dicho factores varían, impidiendo la adaptación de prácticas universales de perforación. Asu vez, estos mismos permiten seleccionar el tipo de broca adecuado y mejorar el máximo rendimiento del mismo. En cuanto la voladura y los explosivos, se revisan las variables fundamentales que ejercen una influencia sobre el resultado de un disparo y así realizar un estudio comparativo de los agentes explosivos en uso, tratando de interpretar el mecanismo de la explosión y a la vez aplicarlo a las diferentes formaciones presentes en Cerro. Finalmente, se describe la organización del sistema de seguridad y las obligaciones de este comité en la industria minera.

Aug 20, 1965

Geophysical surveys are currently being carried out over mineral prospects all around the Pacific Rim. Many of these surveys are successful in locating mineralisation in porphyry intrusives, mesothermal environments, and epithermal vein systems. A number of examples of surveys in Indonesia and Papua New Guinea are presented, which show the successful application of various geophysical techniques to the discovery of mineral deposits on the Pacific Rim.

Jan 1, 1999

By Ralph H. Sweetser

IN the recent world-wide deflation of commodity prices the coal industry, including both anthracite and bituminous coal, had reached a level where the actual delivered market prices received by the operators were usually less than the cost of production. Many steel companies and public utilities, operating their own "captive" mines, could have bought coal during the past three years for less money than the true cost of coal produced at their own properties. Competition within the coal industry itself was cruel to the point of profitless operation, and the competition of other forms of fuel was bearing heavily on the coal producers. They were thus forced into methods of production and utilization that they had hitherto ignored; there had been almost complete absence of any appreciation (by the bituminous operators especially) of the necessity of real research work in finding better methods of preparing coal for specific uses, and in finding new and profitable uses for different kinds and grades of coal.

Jan 1, 1933

By Adil Aledresse, N. Emre Altun, Bern Klein, Nuri Hmidi, Brent Hilscher

A study was conducted to investigate high gold grades in water lines and carbon fines collected from the Musselwhite gold recovery circuit. It was discovered that fine magnetic particles in the overflow from the carbon fines settling tank launder had high gold grades ranging from 2,000 to7,000 g/t. The -37 micron fraction had up to 17,000 g/t gold. Scanning electron microscopy revealed the gold was attached to the surface of iron particles. The objective of the study was to identify possible mechanisms that result in the attachment of the gold to the magnetic iron particle surface and to recommend process modifications that would reduce these types of gold losses around the carbon circuits. Solid and solution samples were collected from the gold recovery circuit and analysed. Two possible mechanisms were identified including gold cementation onto iron and heterocoagulation of colloidal gold onto iron oxides in the elution column. Possible sources of the colloidal gold include reduction of gold cyanide complex to metallic gold in the carbon regeneration kiln and gold detached from cathode in EW cell. Based on SEM+EDX, the sources of iron were natural magnetite and roasted iron sulphides. Thermal reduction of gold is believed to be the cause of dendritic gold from the carbon regeneration kiln.

Jan 1, 2014

By H. Ishimoto

It always has been a serious issue to improve safety in mine sites, demolition work sites, and civil engineering work sites. Especially, collision accidents caused by construction equipment damage not only the productivity of operations but also the health and life of workers in those work sites. To solve this problem, a variety of worker auto-detection means are developed so far, but they have not still become widely used in actual worksites. There have been two controversial points in the prior methods. One is that they were not enough in respect of the detection accuracy and certainty, and the other one is that the information of the detection results was not comprehensible to the operator of equipment. In this paper, the functional requirements of the obstacle detection system in earth moving work site is redefined at first, and then, it is proposed to apply a stereo vision to the obstacle detection system for an excavator. The system consists of horizontally arrayed two digital cameras with low distortion lens, an image processing controller, and a monitor for an operator in the cab. Stereo vision calculates the depth image from images of two cameras and detects the presence of obstacles, its distance, direction, and dimensions. Sensed obstacles are informed to the operator in the monitor image. Preliminary experiments are conducted with a stereo vision system mounted on a real equipment in a demonstration site. The result shows that two controversial points of the conventional technologies are improved, and that the applicability of this system is validated.

Aug 1, 2013

By Michael Schultz, Gregory Sanders

In 2017, the North Texas Municipal Water District (NTMWD) initiated the design of the Sister Grove Regional Water Resource Recovery Facility (SGRWRRF) to provide additional treatment capacity for future population growth within the Lavon Lake watershed. To provide a discharge location for SGRWRRF approximately 4.5 miles of 2.4- meter (96-inch) internal diameter pipeline will be constructed, including 2.3-kilometer (7,800) feet and 487-meter (1,600 foot) long tunnel segments. This paper will discuss the anticipated geology of the two tunnel segments, selection of the tunnel alignment, the anticipated initial tunnel support requirements and other aspects of the project design

Jun 13, 2021

By Michael Karmis, Syed Muhammad Tariq, Zeshan Hyder

This paper analyzes the blast design for lime stone quarries of two major cement plants in Pakistan. The production blast of these quarries was resulting in excessive boulders production. At some instances, the rate of boulders production was approximately 10%-15% of the main production blast i.e. if a round of main blast gave around 4000 tons of material; almost 400 to 500 tons of that material was in the shape of massive boulders. This gave rise to increased operating costs requiring boulders collection, drilling and secondary blast.

Jan 1, 2012

By T. Egleston

The materials containing copper which are refined in the United Statrs, are, for the most part, the natiye noppers of Lake Superior. IJntil quite recently but little pig copper Was made for sale, and that came principally from the pure sulphorous ores of New England and the Sonth, and was generally sdd to reSneries not far from the ore filrnaceu. A stnall aiuoiint found its way into the'niarket which was produced either as the by-product of the treatment of gold and silver ores, or as the result of the treatment of impure copper ores; but both these grades, on account of the impurities they contained, were loolced on with stlspicion, and were not sought for. A11 the grtlGis of pig coppcr are sold by the unit of oopper contents, a great redtiction being made in the price when impurities are present. There are at the present time only three works which treat native copper, the two of the Detroit and Lake Superior copper Company, and the works of C:G. Hussey & Co., in Pittsburgh. There are a few works ivhich smelt sulphuroris ores and refine their pig; bo sides these t1le1-e arc a few siuall works where gig copper is refined uuly. Some of these purcIlase blscir copper, refine scrap, or simply refine such grades of ingot copper as are found in the market, but nlostly that from Lake Superior, for the purpose of getting it into swh shapes that can be handled cpmtriercially to advantage, such as in making large plates or high grades of wire fir electrical purposes. A nomher of such works are situated in the Xaugaturk Vatley aud elsewhcre in New England. The recent discoveryof vnlt~sblc ores in Ariarona makm it probable that within a few year8 the refining of capper In the United States will make great develupments. Up to the time of the discovery of the mines on Lake Superior, only a very small quantity of native copper had ever been foond, not sufficient to justify the erection of worlrs fbr its special treatment. It had, besides, never been found in very large maweq so that the discovery of greabblocks of it presented serious difficulties, not oolp in mining it,-I- but in bringing it into a merchantable condit'ion. It seemed a very simple process to melt these large maws,

Jan 1, 1881

By H. T. Mikkelsen

Mineral production implies emissions of particulate matter (dust), noise and vibration that may cause conflicts with neighbors living nearby. In Norway a few conflicts has been brought to court, the latest in 2006. This paper discusses dust emissions and dust depositions (dustfall). The pollution authorities have accepted monitoring of dustfall instead of suspended dust as the first step in conflict cases concerning small and medium sized enterprises. In the case of exceeded limit values, the second step is to require monitoring of suspended dust and next the implementation of control actions to reduce dust emissions. Dustfall monitoring programmes carried out at six mineral production plants in Norway, show that the mineralogical rates of dustfall are rather low a few hundred meters away from the plants or the tailings disposal. They are mostly considerable lower than the limit value of 5 g/m²/30days accepted by the authorities. Seasonal variations between mineralogical and organic dust fractions can be observed in Norway, with higher content of mineral dust during winter time. Other sources to mineralogical dust can be recognized. During winter time wear of road pavement and sand on icy roads can give high emissions of mineralogical dust to the ambient air. Parallel monitoring of suspended dust and rates of dustfall indicate that dustfall can be used to estimate the level of suspended dust. A model for estimating suspended dust based on records of dustfall is presented.

Jan 1, 2007

By C. Tissot, R. Palmer

"Due to the low concentrations of gold, direct measurement of gold concentration in ore on belt has not been seriously considered to now. Pre-concentration or sorting strategies have largely consisted of particle sorting based on secondary characteristics such as colour, which can be successful in select cases. CSIRO has produced sample measurement results using gamma activation analysis of ~300 gm samples with accuracies of around 30 ppb at best. With this encouragement, a feasibility study into gold ore measurement on belt for the purpose of sorting pods of gold ore has been undertaken. The study described here included, prototype design options with existing industrial Linacs, extensive Monte Carlo modelling of measurement sensitivity and shielding, further sample measurement, a study of the interaction of target measurement accuracy and sorting efficiency, and a rough estimation of potential economic benefit. The projected model sensitivity of around 0.1-0.15 ppm (1 standard deviation) in 10 seconds for 1 ppm average feed result in good bulk sorting performance and intriguing economic potential.INTRODUCTION Pre-concentration or sorting strategies for gold ores have largely consisted of particle sorting based on secondary characteristics such as colour or density, which can be successful in select cases (Klein, 2010). No method is available to measure gold content for sorting in particles or even in bulk on belt, principally due to the low concentrations of gold present. In fact, in many cases it is difficult to do rapid bulk grade measurements of base metal ores with concentrations many orders of magnitude higher. By a fortunate quirk of nature gold is particularly amenable to gamma activation analysis (GAA). CSIRO has performed extensive work in GAA of samples of crushed ore (Tickner, 2017). This has resulted in the Photon AssayTM technique that is currently being commercialised through the CSIRO spinoff company Chrysos. The technique relies on the recent availability of industrial high intensity X-ray sources such as Linacs which are currently being used in industry for security, medical and sterilisation applications. This development has led to CRC ORE funding a feasibility study to determine whether on-belt measurement of gold concentration is possible at a rate and accuracy sufficient to be useful for bulk sorting, where pods of ore are diverted rather than individual rocks. The study in the first instance is based on Monte Carlo modelling that has successfully predicted the performance of the sample based gold measurements. As well as the measurement feasibility consideration was also given to the likely heterogeneity of gold ores and hence the degree to which useful separation could be achieved. This is then tied to a back of the envelope evaluation of the order of magnitude economics of bulk sorting in an example deposit."

Jan 1, 2017

By Alfred Wild

The Kraftile Co. plant, Fremont, Alameda County, Calif.--the largest producer of glazed, structural wall units west of the Rocky Mountains--maintains modern processing facilities to evaluate and blend a wide variety of clays from several sources to produce quality products. The report desribes the prospecting, exploration, and test methods used to locate raw material sources and covers processing methods, cost factors, and trends. Also, the geologic and ceramic factors are considered in a general discussion of the economics, potentials, and requirements of clays as raw materials for ceramic tile manufacturing.

Jan 1, 1963

By E Nettleton, A Melkumyan

A probabilistic system for autonomous tracking of excavated ore in mining would be highly valuable. Currently, mine sites can have a vast array of sensors; examples include excavator load cells, bucket volume estimators and haul truck strut pressures which can be used to gather information about the excavated ore at different locations. These sensors can be utilised efficiently to increase the accuracy of mine estimates by introducing a real-time ore tracking system. This requires the introduction of a probabilistic ore tracking framework to consistently fuse information from any sensor input. Current modelling practices are manually intensive, deterministic (no recognition of the quality of data) and generally not a complete end-to-end system. This paper will provide a novel method for tracking extensive ore properties (mass, volume) and intensive ore properties such as chemical composition (eg Fe per cent, SiO2 per cent, Al2O3 per cent). This method is proved to ensure that correct correlations between states are conserved as material is transferred, combined and/or separated at different locations with any configuration of sensor inputs. This ensures that consistency of estimates is maintained and other benefits such as real-time probabilistic reconciliation can be implemented. A method for combining material of different mass and chemical compositions is also developed to enable accurate and efficient operation of the system. Representative experiments on a small-scale and a larger field trial which mimic the mining processes of excavation, haul and unload to ROM Stockpile will be used to verify the approach.

Sep 26, 2011