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By T. L. Carpenter

"The presence of excessive water in the Gibraltar East Stage 1 pit initiated studies into the ground-water conditions that might be expected in mining the Granite Lake and Pollyanna pits. Hydrologic information obtained from a pump test program in 1974 indicated that deep-well dewatering could be successfully achieved. In 1976, a deep-well dewatering system consisting of eight wells was installed on the periphery of the Pollyanna pit . it has been responsible for a significant decrease in mining costs.This paper presents a brief summary of the engineering principles involved in the design of the Gibraltar dewatering system and the problems encountered in the installation and operation of deep-well pumps. IntroductionGibraltar Mines is an open-pit copper-molybdenite mine located approximately 230 air miles north of Vancouver in the central interior of British Columbia (Fig. I). The property consists of three separate major orebodies; Gibraltar East, Granite Lake and Pollyanna (Fig. 2). Mining commenced during the summer of 1971, in the Gibraltar East Stage 1 pit. The Granite Lake Stage 1 pit was mined from mid 1974 to mid 1976. The Pollyanna Stage 1 pit is currently being mined and the Gibraltar East Stage 2 is being developed for production. This report is intended as an outline of the studies and tests leading up to and including the installation of the Pollyanna pit dewatering system, the problems encountered and the results obtained.GeneralIn the summer of 1973, mining in the Gibraltar East pit progressed below ""daylight"" on the down-hill side and ground water very quickly became a costly nuisance in the day-to-day mining operations. Mining, maintenance and blasting costs reflected these problems. Concern was also voiced about adverse effects of ground water on pit wall stability. This concern later became a reality in the Gibraltar East and Granite Lake pits. A study was initiated to investigate various methods and costs of dewatering the pit areas. The study included in-pit sumps, deep peripheral wells and a drainage gallery system located below the pits."

Jan 1, 1980

By G. W. Zhang, Changsha Research Institute of Mining and Metallurgy, X. Xiao, Y. Long, L. L. Huang

"The paper presents a scale-up and design method of vertical screw stirred mill, in which the closed circuit of mill and hydrocyclone was assumed as one factor, theoretically regardless the affects inside system of the mill and hydrocylone. The specific energy is chosen as a scale-up criterion, based on the premise that when fed the same feed material, mills of different sizes delivering the same specific energy will yield products.Batch grinding tests are conducted to determine the specific energy, and combined with industrial production data, scale-up and design of vertical screw stirred mill for industrial production are accomplished. Having developed this method for the vertical screw stirred mill used in regrinding duty of iron ore in Ma Steel, it has now been successfully applied in other installations.INTRODUCTIONThe Towermill was developed in Japan in the 1950s, by the Tower Mill Kubota Corporation, it was fine and ultra-fine grinding mill of the metallic ores and concentrates. Due to the rapid development of metal mining and useful minerals disseminated fine, fine grinding and ultrafine grinding equipment has also been more wide used in minerals processing industry. Typical fine and ultra-fine grinding mil are the Vertimill and Stirred Media Detritor (SMD) Mill of Metso, Eirich Towemill, Outotec HIGmill, FLSmidth VXPmill, Xstrata Isamill and the vertical screw stirred mill (JM) of CRIMM, etc.JM series of vertical screw stirred mill were invented by Changsha Research Institute of Mining and Metallurgy in the 1980s. Energy saving and consumption reducing have been achieved through the optimization and engineering practice. More than 500 units JM series of vertical screw stirred mill are used in the iron ore, copper ore, copper-molybdenum ore, molybdenum ore, Pb-Zn ore and Au ore."

Jan 1, 2016

By B. McFadzean, I. Achaye, T. Chidzanira, J. Wiese

"Froth stability has an overriding effect on metallurgical recovery and grade for many ore types. Froth recoveries of less than 10% are common for low stability froths such as those in sparsely mineralized ores or in cells at the back end of flotation circuits. It is well known that, aside from chemical factors such as frothers and electrolytes, the mineral particles themselves have the dominant influence on froth stability. The particle properties of size and hydrophobicity are expected to have the greatest effects on froth stability. The aim of this study was to understand the effects of particle size on froth stability and to quantify these relationships.The study compared a synthetic ore of pyrite and quartz, with carefully controlled size ranges and hydrophobicity, with conventionally milled platinum-bearing UG2 ore and the bulk reverse flotation of hematite ore. A novel bench-scale continuous column flotation cell and continuous mechanical hybrid cell with large relative froth volumes, as well as a three-phase froth stability column were used to characterize the froths.It was found that froth stability could be related to the concentrate particle surface area by a Langmuir-type relationship. This is indicative that the mechanism by which particles stabilize the thin films in froths is similar to the mechanism by which surfactants lower surface tension. Different froth stabilities were found for different ores and this was thought to be the result of different particle sizes and distributions, which resulted in different packing densities in the thin films and Plateau borders. Interestingly, there was a clear relationship between the feed particle size and the froth stability even though froth stability was dependent on the concentrate particle surface area. It seems that the feed particle size is a good predictor of the surface area of particles in the concentrate. Concentrate particle size did not show a clear relationship with froth stability since it was already shown that it is both the size and the amount of the particles in the froth that contribute to the stability.INTRODUCTIONThe stability of the froth in froth flotation is important to the recovery and grade of the valuable mineral. Too stable a froth and the grade is reduced; not stable enough and the recovery may be compromised. Platinum-bearing ores with fragile, poorly mineralised froths are known to have froth recoveries that are routinely less than 10% (Crosbie et al, 2009). There are a number of chemical, physical and operating parameters that can affect froth stability, including reagent dosages, air flow rate, pulp density and particle properties. Arguably, the largest contribution to froth stability is from the particles that stabilise (or destabilise) the thin films in froths. Particle size, hydrophobicity and shape all affect froth stability to some extent."

Jan 1, 2016

By Frands Jensen, Erik Eriksson

"Haldor Topsoe’s Wet gas Sulfuric Acid (WSA) technology has been proven in a number of industries converting sulfurous gasses to concentrated sulfuric acid. In the metallurgical sector plants have been delivered handling SO2 gasses from copper, zinc, molybdenum, and lead ore. WSA has high energy efficiency and allows autothermal operation from feed gas strengths as low as 3.0% (volume). Recent variants of the WSA process have been developed that allow very high SO2 conversion efficiencies of over 99.9%. This paper describes the technology, its advantages and industrial achievements.The WSA technology is well suited for production of concentrated sulfuric acid of commercial quality from the sulfur dioxide (SO2) gas that inevitably emerges from the metallurgical processes. Some of the features that make the WSA technology attractive for this application are:- High SO2 conversion rates (up to 99.99%)- High energy efficiency leading to a low autothermal point (~ 3% SO2)- No need for gas cooling and drying to produce concentrated sulfuric acid- No production of waste- Very low cooling water consumptionThis paper describes the WSA process principles and highlights features that make this process attractive for handling SO2 gases."

Jan 1, 2014

By C. Diaz, S. W. Marcuson, K. I. Burgess

Deep roasting in fluid bed roasters is the first unit operation in Inco&apos;s "roast-reduction smelting" process for the treatment of nickel sulphide concentrates. The roaster product, a low sulphur calcine, is reduction smelted with coke in an electric furnace to yield a sulphur-deficient matte which is then converted to low (<1%) iron matte in Peirce-Smith converters. Due to the deep roasting, a minimal amount of sulphur dioxide is evolved in the smelting and converting stages. Sulphur is eliminated from the concentrate almost exclusively in the roasters in a single, continuous, strong, gas stream suitable for treatment in an acid plant. This paper discusses the commercial scale testing of deep fluid bed roasting of nickel concentrate at Inco&apos;s Thompson Smelter as part of two commercial scale campaigns on roast reduction smelting conducted in 1981-1982. Slurry feeding, practised during the second campaign, permitted excellent control of the air/concentrate ratio in the roaster and, in turn, good control of sulphur elimination (about 80% of input). Smooth autogenous operation with high oxygen efficiencies (about 95%) was promoted by operating at bed temperatures of830°C to 850°C with calcine recycle. High throughputs and the desired metallurgy were achieved. The extensive testwork conducted during the two experimental RRS campaigns demonstrated thot deep fluid bed roasting of nickel concentrate at high oxygen efficiency is a technically viable operation.

Jan 1, 1994

By D. Moffat

Rio Algom Limited has mined uranium at Elliot Lake, Ontario for 20 years. The production of this energy-generating element results in the need to dispose of low-level radioactive solid wastes and liquid effluents. Because of the wet-temperate climate at Elliot Lake, the liquid effluents are of particular importance. Radium-226 is the isotope which requires most attention, and the current practice for its control is by addition of barium chloride and retention of the resultant precipitates in large settling ponds. Analyses of typical effluents and waste streams are discussed and typical levels of radium-226, thorium-230, thorium-232, thorium-228, lead-2iO, polonium-2iO, and uranium isotopes are presented.

Jan 1, 1979

By M. Duncan

Lightweight, high-pressure cylinders for compressed hydrogen storage are essential components for fuel cell vehicles. Storage volume and mass are two key considerations. Current on-board hydrogen storage systems are based on a maximum pressure of 350 bar. While 350 bar systems are excellent solutions for many applications, some situations require higher storage densities due to space restrictions. As a result, significant research and development work has been expended by cylinder manufacturers, systems providers, testing agencies and automotive manufacturers to develop 700 bar systems with reduced storage volumes. Dynetek Industries Ltd. has proactively developed several 700 bar storage cylinders based on a seamless aluminum liner over wrapped with a carbon fiber composite. This paper presents the challenges and processes involved in the design, testing and certification for Dynetek Industries Ltd. 700 bar cylinders. This paper also provides reasoning for further volume and mass optimization of compressed hydrogen cylinders through the establishment of realistic cylinder usage parameters in standards. In particular, the overly conservative fill life requirement for cylinders is examined.

Jan 1, 2005

By K. N. Subramanian, H. Kanduth

"It is well known that chalcopyrite can be dissociated into simple sulphides by heating with elemental sulphur at about 475°C:CuFeS2 + S -> CuS + FeS2Experimental work was undertaken to determine whether this ""activation"" could be used to advantage in the selective leaching of copper from chalcopyrite concentrate.A method of treating copper concentrate with molten sulphur was developed and the activated product was leached in dilute sulphuric acid using oxygen, ferric iron or manganese dioxide as the oxidant. The object was to obtain a solution suitable for electrowinning with minimal purification, but it was impossible to obtain rapid extraction of copper without simultaneously dissolving a large proportion of iron. This was attributed to the fact that some of the copper was present as a low iron-copper sulphide (idaite) and that the pyrite formed during the ""activation"" step was more easily oxidized than natural pyrite."

Jan 1, 1973

By J. Kuipers, R. W. Lawrence, P. B. Marchant, W. Brooks, J. T. Chapman

"Bioleach testing and piloting was conducted on refractory gold sulphide concentrate from Austin Gold Venture in Nevada during 1988. The objective of the test programme was to determine the technical and commercial viability of bioleaching as a concentrate pretreatment step prior to gold extraction by cyanidation. Baseline CIL cyanidation typically resulted in < 20% gold extraction from the Austin concentrate. Bioleaching enhanced gold extraction up to 95% using conventional CIL techniques. This paper summarizes the bioleach test programme and results, including pilot plant studies onsite, and describes the commercial design details for a possible retrofit of the Austin flotation tailings leach circuit to accommodate 20 tpd and 40 tpd capacity concentrate bioleach facilities.INTRODUCTIONBioleach testing on a refractory carbonaceous sulphide concentrate from Austin Gold Venture (AGV), was initiated in late 1987 as part of an ongoing programme at Austin to investigate alternatives to concentrate smelting. Preliminary batch biooxidation tests at Coastech indicated that over 90% gold extraction by carbon-in-leach (CIL) cyanidation of the bioleach residue could be achieved, compared with less than 20% gold extraction on untreated concentrate by similar CIL processing.Subsequently, a more rigorous laboratory study was undertaken at Coastech to establish continuous biooxidation operating criteria on a bench scale. The objective of continuous testing in the laboratory was to provide confirmation of enhanced CIL response based on continuous bioleach products and to determine key process operating and design parameters for pilot testing. The success of the laboratory test program led to the installation of a mobile pilot plant at Austin Gold Venture. The plant was operated by Coastech and AGV during 1988 to provide scaleup data and design criteria for commercial design and feasibility analysis. Based on pilot plant operating data, a detailed commercial bioleach plant was designed as a possible retrofit to the existing 1000 tpd CIL plant. Capital and operating costs were estimated to provide a commercial feasibility study of bioleaching as an oxidative pretreatment for Austin refractory concentrate."

Jan 1, 1989

By J. E. Udd, L. B. Geller

"Responding to requests by the Canadian mining industry and the mine regulatory authorities, the Canada Centre for Mineral and Energy Technology (CANMET) undertook a major research project on evaluation of wire rope testing in 1986. The objectives were to document, analyze, and clarify - in basic operational terms the reasons for ongoing mine shaft wire rope failures that occur despite mandatory non-destructive testing (NDT) with electromagnetic (EM) instruments on a routine basis.The project&apos;s investigative scope and depth was unprecedented. It could not have been successfully completed without the wholehearted cooperation of industry, research organizations, and mine-inspectorates at both national and international levels.The project&apos;s goals were attained. II was shown that, at present, the problem areas in Canada are oj a human , rather than of a hardware-related nature. Consequently, the principal recommendations are concerned with a more widespread, more uniform and thorough operator training and certification process at industrial and regulatory levels. Secondary suggestions concern areas of hardware-related improvements.In this paper an up-to-date general overview is given of the major project results. A n extensive reference list is also provided of papers that contain all relevant documentation in detail."

Jan 1, 1992

By A. J. Antony Chettupuzha

Electronic Product and Process Management [EPPM] systems provide the capability to establish and map information flow between different parties in a construction project as well as model project processes. Much of the information relating to processes and their structure, the actors that operate them, and the data associated with each instance of a process is encapsulated within workflows. The wealth of information contained in an EPPM system can be exploited to extract knowledge that can provide significant cost benefits to construction companies. Workflows provide an ideal medium for the capture of knowledge over the course of a project lifecycle. We demonstrate how this knowledge may then be used to analyze workflows and determine metrics that establish the suitability of workflows to construction processes. We present a conceptual approach to measure the performance of a workflow, its constituent components and evolution, which may be used to lay the foundation for establishing paragon workflows suited to classes of construction activities.

Aug 1, 2013

By Neri Roux, Ross Gilders, Yemi Oyediran, Leo Cheung

Quest Rare Minerals Ltd. is developing their Strange Lake B Zone REE deposit located in Northern Quebec. An extensive batch bench scale testing program was launched to investigate open circuit rougher flotation performance under different conditions. The objective of the flotation study was to demonstrate the effectiveness of rejecting gangue minerals to flotation tailings while concentrating rare earth elements as well as yttrium, zirconium, and niobium into a concentrate suitable for further hydrometallurgical processing. Mineralization of interest at Strange Lake occurs within peralkaline granite-hosted pegmatites and minor aplite. The REE and high field strength element (HFSE)-bearing phases are hosted primarily in pegmatites as relatively fine-grained phases or pseudomorphs. The gangue phases comprise of quartz, feldspar, amphibole, and pyroxene. Potential ore minerals comprise predominantly of kainosite, gerenite, gadolinite, zircon, pyrochlore, and gittinsite. These complex mineralogical characteristics increase the difficulty for processing and provide a challenge for choosing the correct reagent scheme in rougher flotation. Process options including reverse flotation to reject the gangue minerals and de-sliming prior to the direct rougher flotation were investigated. Optimization trials were conducted using various reagent regimes and under different flotation conditions. Encouraging results were found using a combination of collector reagents supplied by Cytec Canada Inc.

Jan 1, 2014

By Frank Baczek, R. Q. Honaker, D. P. Patil, B. K. Parekh

Fine refuse slurry impoundment is a requirement for the coal industry to dispose the fines. Impoundment maintenance is an on going problem for the coal industry and its breakage creates environmental as well as financial problems. Deep Cone thickener technology which has been successfully applied in the alumina industry to dewater red mud was evaluated for fine refuse slurry. Preliminary obtained in a pilot-plant test showed that properly flocculated conventional thickener underflow slurry could be thickened to about 52.5 wt % solids and could replace belt filter press. The Deep Cone thickener was also found to dewater clean coal slurry to about 70 wt % solids. Further testing of the unit at other coal preparation plant is in progress.

Jan 1, 2004

By Chris V. Sellathamby

Condition-based maintenance is replacing preventive maintenance in many industrial operations as a result of gains in productivity. Preventive maintenance is strictly time-based which means that as long as the prescribed time is sufficiently short, failures are prevented. The trade-offs between shorter cycles and increased downtime is a fine balancing act. Condition-based maintenance is gaining momentum as the more cost-effective and green solution to finding the optimal maintenance cycle and improving overall productivity. In the mining industry, various parameters of heavy equipment are monitored continuously to provide feedback for maintenance events. However, strain, shock, and vibration, key factors which lead to yielding and fatigue of metal parts, are not generally monitored by built-in systems, mainly due to the complexity of sensor installation and computational intensity of data processing. Scanimetrics has developed a stand-alone, add-on wireless system for measuring strain, shock, and vibration in heavy equipment and components, the data from which can be directly used to trigger maintenance events. The present system is being deployed in tar sands mining equipment. The system consists of a portable display and control unit, a software platform consisting of data management, sensor instrumentation and data analysis, and wireless strain sensor units, which can be easily installed on equipment. Data from the sensors can be gathered throughout the mine site, processed instantly, and used to generate condition-based maintenance events, improving overall uptime of the equipment and overall productivity of the mining operation.

Oct 1, 2010

By B. L. Dorey

"Performance management is a systematic, practical approach to managing people. It is founded on some basic assumptions about people and is designed to focus on people in the work place. Organizing meaningful information and using it to involve people is a cornerstone of this system.Some common sense practices are developed to involve people in an organization&apos;s effort to improve performance. The successful implementation of this program requires solid commitment and total involvement from all levels of supervision and employees for maximum results and lasting impact. All levels of supervision participate in training sessions to tailor the systems for implementation in their areas. This style of management is data-oriented and the bottom line of success is to measurably improve performance. Basic Assumptions about PeopleMost people in an organization, regardless of level, take pride in their work and generally want to do a good job. When performance falls off, there is usually some explanation other than the employee not really caring. People like to know their exact responsibilities and clearly what is expected of them. People like to know where they stand with the boss and would like to be evaluated on what they do and accomplish, rather than on what others think or feel about them. Further, people like to be rewarded for their good results, indeed, to understand what motivates people, we must look at what happens as a result of their actions. Another belief is that supervisors often have a greater influence on the performance of their people than they fully realize. Simply letting people know how important their performance is can have an impact. The Key ElementsGiven these basic assumptions and beliefs about people, some common sense practices have been systematically developed to manage more effectively."

Jan 1, 1989

By H. Utsunomiya

Most magnesium alloy sheets show low deformability in rolling. Edge cracks and transverse fractures are common difficulties. In addition, rolled sheets show well-developed basal texture <0001>//ND. The texture causes high anisotropy in mechanical properties and low formability in subsequent metal forming. Differential-speed rolling, where the upper and the lower rolls rotate at different speeds, introduces shear deformation through the thickness. Not rolling texture but shear texture evolves in the sheet so that the asymmetric rolling can be a method of texture control. However the primary slip system of the hcp alloy, is basal, the shear texture should be also basal. Differences between the two basal textures, i.e., the rolling texture and the shear texture, have not been understood completely. In this study, conventional (same-speed) rolling and differential-speed rolling have been applied to commercial AZ31B sheets at 623K. Microstructures, textures and mechanical properties of the rolled sheets before/after annealing are compared. It is found that the basal texture is more pronounced by the asymmetric rolling. On the other hand, the asymmetric rolling is effective to decrease the grain size and the planar anisotropy.

Jan 1, 2006

By Ludwig Strah

"The paper outlines the history of rubber mill liners beginning with the awarding of the first North American patent rights in 1923. It includes the early-day applications and installations of the 1920s and 1930s through to their present-day application. Over-all rubber mill liner design is discussed in relation to present day installations employing rubber mill liners in various grinding applications. A brief overview is given of a manufacturer&apos;s procedures to produce rubber mill liners.IntroductionIn early 1910, it became apparent that the productive life of the silver mines in Cobalt, Ontario, could be substantially prolonged by mining lower-grade ores.The mining of lower-grade ores required the establishment of treatment facilities which initially employed jaw crushers, stamp mills, jigs and concentrating tables. The recovery of silver in other than a coarse metallic form required the additional step which was introduced at that time: the cyanidation of silver concentrates from the tables. The resultant requirement for increased and improved recovery led to the introduction of grinding mills, i.e. tube mills.Shortly after the introduction of the tube mills to the Nipissing Mine&apos;s mill in 1914, the idea of using rubber as a mill liner material was spawned. However, no action was taken due to the advent of World War I. It is interesting to note that the idea of rubber mill liners emanated from having used pieces of solid rubber tire as an emergency repair on a set of liners when a liner had broken and no immediately available spare was on site.The credit for this ingenuity and subsequent application for a patent on rubber mill liners falls to James John Denny, the mill superintendent, and Rolla Barnum Watson, the general manager of Coniagas Mines Limited. The patent application was formally made on December 3, 1921. The U.S. Patent Office issued Patent No. 1,470,597 on October 16, 1923."

Jan 1, 1982

By G. N. Nnadi, R. J. Mitchell

"The response of cemented backfills subjected to simulated blast loadings is studied using centrifugal modelling techniques. Scaling requirements for centrifugal modelling are developed and the results of the similitude analysis show that an acceleration field is required to capture the true dynamic response of backfill models. Experiments have been conducted at various centrifugal accelerations. The effects of ring blasting were simulated by an impact loading on the exposed fill face. The behaviour of the cemented backfill was monitored with accelerometers as well as dynamic stress gauges.Cemented backfill response to impact loadings was found to depend strongly on simulated gravitational stress level. Results also show that the characteristics of the response changes with distance from the impact. Finally, the results of the models were used to predict prototype peak accelerations, velocities and displacements. The results reported in this study indicate that centrifuge modelling may be a useful tool for dynamic studies of blast damage to backfills. Centrifuge modelling can be carried out at low costs and can be used to design prototype instrumentation systems. IntroductionThe response of cemented mine backfills to blast loadings is of concern to the mining industry because these backfills provide local and regional support during ore pillar extraction. Considerable research has been reported on the static stability (Smith et al., 1983) and on effects of reinforcements on cemented backfills (Mitchell, 1989). However, information regarding dynamic aspects of cemented backfill is limited. O&apos;Hearn and Swan (1989) reported on the response of cemented backfill to blast loading, but these blasts were not very dose to the backfill . A schematic representation of a rock-backfill system is shown in Figure I.The mechanics of transfer of explosive energy to rock and subsequently to the backfill, and the resulting responses, are complex. Achison (1968) listed more than twenty factor s affecting the blast fragmentation of rock and grouped these into the categories of explosive parameters, charge parameters and rock parameters. Although significant advances have been made, during the past two decades, in understanding the mechanics of blasting, the degree of uncertainty associated with predicting the behaviour of backfills subjected to dynamic loadings makes the application of simple design safety factors insufficient. Comprehensive testing programs or prototype instrumentation is required to evaluate the risks associated with blast or earthquake loadings on backfill."

Jan 1, 1991

By Jianzhong Liu

Based on the characteristics of overburden rock strata movement, surface ground subsidence and casing deformation and failure, a tension-shear combination failure model of surface borehole was set up. The main controlling factors of the mining-induced deformation and failure of surface borehole were researched with this failure model and the limit analysis method. The mining methods and geology conditions mechanics action mechanism to surface borehole and its time ?space evaluation rule was found. The surface borehole deformation and fracture rule were advanced. It provides theoretical support to optimizing layout, structure type, security measure and local casing protection of surface borehole.

Aug 1, 2013

By Randolph A. Pax

"The internal operation of a tumbling mill is a very hostile environment and precludes the sustainable operation of internal sensors to measure the mechanisms of charge motion and breakage events. Instead indirect methodologies are required to expand the current understanding developed within a framework of perfect mixing of the mill contents. A number of measurement approaches have been successfully used to explore the operation of SAG mills including strain instrumented lifter bolts, mill shell strain measurement and thermal (energy balance) of operating mills.Early acoustics measurement was developed by Hardinge using a 'microphone' located close to the expected toe location. This signal was an indicator of the mill fill. Improvements were implemented with the use of two microphones straddling the toe location to try to increase the sensitivity of the measurement and reduce ambiguities. Further improvements included a filtered signal indicative of steel interactions. Unfortunately, the mechanisms of signal generation and the complexity of the processes do not provide a consistent signal.In recent years, advanced acoustic measurement using arrays of microphones utilising signal processing techniques have been implemented as SmartNoise and validated on over 30 mills. This paper will discuss the results obtained with signals such as water holdup, mill shell steel hits and two each of the toe and shoulder angles. An estimate of the internal mill component wear rates is also accessible.Advanced acoustic measurements with wide bandwidths when combined with physics models and process understanding has achieved a step change in the understanding of the dynamic internal operation of a tumbling mills on time scales of 80 ms. These techniques have been used extensively on SAG mills, but have also been applied to FAG and ball mills. Acoustic measurement is used for the rapid diagnosis of mill conditions and holistic control for optimisation and stability."

Jan 1, 2016