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Acupan is considered to be an intrusive centre as several igneous phases have been emplaced in the vicinity of the mine over the past 8 Ma. They include the Lucbuban gabbro, Virac granodiorite, Ampucao dacite porphyry (ADP), Hartwell plug, Itogon plug and the multi-phase Balatoc diatreme. These intrusives have high-K calc-alkaline affinities and are grouped together as the Virac Complex.Porphyry-style mineralisation formed during the final crystallization of the ADP in the late Pliocene, with the deposition of two vein stages from high-temperature hypersaline magmatic-hydrothermal fluids. K-silicate alteration halos surround the first stage of veinlets (stage I); they are surrounded in turn by a propylitic assemblage. White sericite and/or intense propylitic halos envelop the second stage of veinlets (stage II) and grade into a weak nrnnvlitir accPmht o

Jan 1, 1990

By S Morgan, D J. Bradshaw, S Schwarz

The characterisation of the flotation kinetic response in future mining deposits is important because the flotation response is affected by changes in ore mineralogy. Current methods for characterising the flotation response of different ore types, such as the JK floatability index test (JKFIT) methodology, require at least 10 kg of feed material. In geometallurgical applications, this material is taken from core samples. Core samples are generally obtained using specialised drills and are limited in nature. Thus, it would be beneficial to develop a laboratory technique that required less sample material but still characterised the flotation response of different ore types. The JK mineral separation index (JKMSi) is a small-scale flotation test that requires significantly less feed material (10 g of sample/data point). This study aims to investigate the JKMSi system kinetics and to validate this technique using the JKFIT proven methodology. The JKMSi flotation kinetics were manipulated by varying selected system parameters. The relationship between these parameters and mineral recovery was used to obtain floatability characteristics of the ore. For an ore sample containing chalcopyrite and pyrite, it was found that the chalcopyrite floatability parameters determined from both the JKMSi and JKFIT tests were of the same order of magnitude and the mass fractions of the fast, slow and non-floating components were similar. For pyrite, the floatability parameters were not of the same order of magnitude, but modifications to the test procedure have been identified, which may correct this.CITATION:Morgan, S, Bradshaw, D J and Schwarz, S, 2012. Julius Kruttschnitt Mineral Separation Index - Small-scale test to characterise the flotation response of an ore type, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 159-162 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

The ongoing need for improved fuel economy, longer engine life, reduced emissions and greater power output has driven the need for lower charge air temperatures. Cuamins will introduce a split loop, single water pump approach to low temperature aftercooling (LTA) in 1987 with the introduction of its 1492 kW (2000 BP) 16 cylinder K Series engine. The LTA system selection process considered performance, durability, fuel economy, and total engine installed cost. The split loop system selected takes full advantage of the engine cooling characteristics to provide optimum charge air temperatures at all speeds, loads and ambient temperatures. Computer simulations and engine tests were used to determine performance for each charge air cooling alternative. The split loop system chosen offers many advantages compared to the other alternative systems studied which included air-to-air and dual loop (two radiator, two water pump) systems.

Jan 1, 1986

By R J. Beazley, M C. Woods

"The International Cyanide Management Code (the Code) is a voluntary industry program for gold miners and associated cyanide transporters and cyanide producers. By becoming a signatory, a company commits to follow the CodeÆs principles and implement its standards of practice.Signatories are required to undergo an initial certification audit within three years and a recertification audit every subsequent three years. Recertification audits evaluate compliance over the preceding three-year period. This approach presents a number of challenges. Golder Associates has undertaken in excess of 75 initial certification audits and 25 recertification audits; more than any other audit firm. This paper outlines some of the challenges identified and lessons learnt from the recertification audit process. Central to the process is the challenge for organisations to maintain commitment to compliance over the full three-year period and effectively address deficiencies or non-conformances that may have occurred during that period in a prompt manner.The International Cyanide Management Institute (ICMI) provides guidance in evaluating deficiencies or non-conformances, which requires consideration of the æcauseÆ, ædurationÆ and æongoing compliance effortsÆ and an assessment of the concept of ægood faithÆ in response actions. Golder AssociatesÆ experience with the recertification process highlights some common deficiencies with Code compliance programs, such as: system breakdowns (leading to ineffective communication between departments or loss of information) exceedance of discharge limits inadequate inspections, maintenance activities and associated record-keeping.Such deficiencies can be attributed to: personnel changes organisational changes or structures management systems (eg integrated or standalone) awareness and interpretation of Code requirements transparency of management decisions with Code implications.We have identified that ongoing programed assessment is an effective strategy in maintaining Code compliance.CITATION:Beazley, R J and Woods, M C, 2013. Cyanide code recertification - the three-year challenge, in Proceedings World Gold 2013, pp 247-254 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 26, 2013

By Frfas C, Parrilla F, Regife J. M

A project to develop the Zinclor electrowinning cell to industrial size is being conducted at Tecnicas Reunidas' Research and Development Centre with Spanish Ministry of Industry support. This project is the final development phase in zinc electrowinning from a chloride medium, the highest ZINCLOR technology development level prior to the industrial scale having already been reached. This paper covers the outcomes and conclusions corresponding to project Phases 1 and 2: Process Selection and Industrial Electrodes (1 m2) design and testing. The most important achievement reached is that there are presently available industrial cathodes and anodes for the Zinclor diaphragm cell giving an optimum response for zinc chloride electrowinning with unit power consumptions between 2.65 and 2.80 kWh/kg Zn, depending on the diaphragm type. Standard electrolysis conditions were: 65 g/L ZnC12, 3 g/L HCl, 160 g/L NaCl, 350 g/t Zn arabig gum as the addition agent, 36¦C, and 400 A/m2 current density. The selection of electrodes, diaphragms and organic additives for the industrial scale tests have been optimised. The complete electrowinning cell development, with electrodes having an active area of I m2, enables the evaluation of Zinclor Technology application for industrial processes.

Jan 1, 1993

By A Parbhakar-Fox, S C. Dominy

The prediction of acid and metalliferous drainage (AMD) from mine waste materials is critically important during all stages of the mine value chain. However, to determine such geoenvironmental characteristics static and kinetic testing of individual waste units must be performed on representative samples. The importance of sample selection cannot be underestimated; it is the single most critical aspect of any geoenvironmental investigation. Poor sampling techniques and inadequate sample selection will contribute to excessive variance, difficulties in interpretation and incorrect assessment. By undertaking mesotextural characterisation based on hyperspectral mineralogical data (with sulfur assay data if available), opportunities to improve sampling strategies are presented. Such data will inform the selection of samples for low-cost total sulfur, paste pH and geoenvironmental logging, which collectively will allow for accurate AMD forecasting and improved sampling practices to be achieved. Once sampled, robust quality assurance/quality control (QA/QC) protocols must be developed where the use of international certified reference standards become obligatory. This is currently not practised, resulting in inter-laboratory discrepancies when undertaking waste classification. Further improvements in geoenvironmental characterisation testing lies in the adoption of blended static testing protocols, whereby blends of waste materials can be efficiently tested so as to give an early forecast as to whether they will produce acidic or metal-laden drainage. Such information is integral in developing a waste schedule that will allow for a non-acid forming waste landform to be constructed right from the start of the operational phase. Ultimately, improvements in this discipline lie in technological innovations with regards to mineralogical characterisation, and by offering geoscience and minerals engineering students a competent education in the discipline. Collectively, this will empower a step-change in AMD prediction and waste handling, and will make the realisation of the United Nations Sustainable Development Goals a reality, rather than a dream.CITATION:Parbhakar-Fox, A and Dominy, S C, 2017. Sampling and blending in geoenvironmental campaigns – current practice and future opportunities, in Proceedings Eighth World Conference on Sampling and Blending , pp 45–54 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By A Yáñez, P Vallejos, R Grau, J Yianatos

In flotation cells, especially in large flotation units, froth management is a crucial variable that should be considered during the design phase or optimised to improve the performance of existing flotation circuits. This paper presents a simulation evaluation of the effect of launder design on the metallurgical performance of an industrial flotation circuit consisting of five TankCell® e630 (630 m3 ) cells in a Cu rougher duty. This analysis was carried out using a new industrial simulator, which was built on a wide database collected from many industrial concentrators. This tool is currently incorporated into HSC Chemistry® software and allows evaluation of the effect of launder design on mineral froth recovery, water recovery, entrainment, and other variables to be quantified. The industrial flotation circuit was evaluated under different launder design scenarios, considering an actual flotation circuit that includes TankCell® e630 cells for calibration and as a reference (baseline). Firstly, two different designs were evaluated in the full circuit: a standard launder design and a new launder technology. It was found that the new launder technology enabled improvement of the mineral recovery along the circuit, mainly for coarse particles, due to the improvement in froth mineral recovery. Next, the partial upgrade of the launder design along the circuit was analysed. Thus, the new launder technology was evaluated in the first and the last two cells of the bank. The results showed that upgrading the launders in different cells along the circuit delivered an increase in the final recovery with respect to the baseline, with a partial impact on the concentrate grade. However, these changes are less than those when evaluating the full upgrade scenario. A partial launder upgrade either in the first or last two cells of the bank showed similar final recoveries, but the latter enabled a slightly higher concentrate grade (about 1 per cent higher) to be achieved. Finally, the evaluation of launder design using the industrial simulator made it possible to estimate its effect on variables that are not commonly obtained from plant surveys, including froth recovery per particle size, collection recovery per particle size and liberation, gangue entrainment and bubble loading grade.

Aug 24, 2022

The Louvicourt Mine is located 600 km north of Montreal in the province of Quebec, Canada. The owners are Aur Resources Inc (30 per cent), mine operator, Novicourt Inc (45 per cent) and Teck Corporation (25 per cent). It is an underground mechanised operation with a total work of 290 employees. Since 1994, the mine production is 11 120 456 tonnes at 3.60 per cent Cu, 1.51 per cent Zn, 26.07 g/mt Ag and 0.96 g/mt Au. At a rate of 4300 tonnes per day 365 days per year. Louvicourt Mine is a copper operation since 80 per cent of our revenue is from copper. The mining method is transverse blasthole stoping, mining primary and secondary stopes. The stope dimension is 15 m wide by 30 m high and 10 m to 80 m long for primary stopes. The secondary stopes are limited at 25 m long. Close to 100 000 metres of production drilling per year is required for 115 mm and 165 mm diameter holes. Backfilling is done with pastefill from the start of the operation in 1994. The binder ratio is 4.5 per cent in primary and two per cent in secondary stopes (80 per cent slag and 20 per cent cement). Development requirement to maintain production was 5000 m from 1996, 1997, 1998, 4200 in year 1999, 3200 m in year 2000 and an average of 2500 m in 2001 and 2002. Typical 6.0 m + 4.3 m, 4.9 m + 4.6 m and 4.5 m + 4.6 m headings. In addition more than 1500 metres of development will be excavated in/under paste backfill before 2004. A total of 60 mobile units are required among which for lateral development (three two boom electric hydraulic jumbos û AC Boomer 322, four electric hydraulic roofbolters û Maclean MEM-928 and AC Boltec PL350 and two anfo loader truck û Dux) and for production (four ITH drills û MTI, one electric hydraulic longhole drill û AC Simba H1357, eight LHD û AC-Wagner ST8-B, 1 LHD ST-1000 and two haulage 30 tons trucks û Dux. The 1 January 2002 reserves are 4.1 M tonnes grading 3.1 per cent Cu and 1.9 per cent Zn at an NSR (Net Smelter Revenue) of $US 53. The operating mining costs were at an average of $US 23 from 1996 to year 2000 and $US 25 in 2001. The operating costs ranged from a low of $US 0.41 per pound of copper in 1999 to a high of $US 0.49 per pound of copper in 1998.

Jan 1, 2002

By M J. Thurley, M Wimmer

To assess the present-day functionality of large-scale sublevel caving at LKAB Kiruna a comprehensive measurement program was undertaken involving blast function, fragmentation and gravity flow. As part of this assessment, a fragmentation measurement trial was performed based on 3D imaging of the drawpoint and corresponding bucket load of the underground load-haul-dump (LHD) excavator. 3D image data from stereo photogrammetry was collected and an automated image analysis strategy developed. A number of data sets were collected for each of the drawpoint and LHD bucket, along with sieving results for four of the LHD bucket loads (totally about 70 t). Two of the sieving results were used to inform the automated image analysis strategy, and two were held back as a comparison. Large variations in the visible particles are apparent when comparing corresponding drawpoints and LHD buckets highlighting the impact of sampling location and the need to measure large quantities of data in order to avoid bias from small samples. The results show that 3D imaging and analysis can produce fully automated measurement and analysis of the visible particle size distribution. Although this is not the same as the sieve-size distribution it provides useful estimation of both the larger size classes and a bulk estimate of fine material below approximately 60 mm. The 3D stereo photogrammetry measurement system used produced very high 3D point density but this was achieved using a custom up-sampling technique which significantly smoothed the data, removing small particles, smoothing edges, and this negatively affected the particle delineation algorithms.CITATION:Thurley, M J, Wimmer, M and Nordqvist, A, 2015. Blast fragmentation measurement based on three-dimensional imaging in sublevel caving drawpoints and underground excavator buckets at LKAB Kiruna, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 763–774 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By M Hino, Y Sasaki

Sustainable handling of municipal waste and sewage sludge has an important goal to recycle resources without supply of harmful substances to humans or the environment. The gasification mechanism of phosphorus from municipal waste and sewage sludge during the incineration process has been investigated to develop a phosphorus recovery system. Quadrupole mass spectrometer coupled to an electric furnace is applied to study the vaporisation behaviour of phosphorous gas phases from municipal solid waste (MSW) incinerator ash of sludge during solid-state reduction by carbon. Measurements are carried out in vacuum conditions of 2 x 10-6 Torrs and furnace temperature range 573 - 1773 K, at a heating rate of 7.22 K/minute. It has been found that most of the phosphorus is vaporised as PO2, P2 and P4, in agreement with thermodynamic estimation despite a shift in the temperature regimes.

Jan 1, 2006

By Mahyera A, Sakashita B, Ahmed U, Abou-Sayed AS

Gas in U.S. coals is primarily composed of 90 to 99 percent methane and up to 10 per- cent carbon dioxide. In composition and heat- ing value, this coal-bed gas is similar to natural gas and can be introduced directly into commercial pipelines after standard condition- ing. The high permeability cleat system in the virgin coal can be exploited in order to drain the coal gas well in advance of mining. Two premining drainage methods have been extensive- ly evaluated in the U.S.; they are 1) horizon- tal boreholes collared from within the mine, and 2) vertical drilling from the surface with fracturing. Limited-size fracture treatments are advocated in order to prevent potential roof damage and the need for added support. An engineering approach to predicting gas flow for different drainage techniques near mining locations is presented. Results can be used in design, i.e. pipeline, compressor. Coal gas drainage from a horizontal borehole and a treated (contained fracture) vertical well for a 6 foot seam have been evaluated. Based on these results, it was concluded that selection of gas drainage techniques will depend primar

Jan 1, 1982

By P Christen

The Ernest Henry Copper gold mine situated in North West Queensland, Australia, is owned and operated by Xstrata Copper. Currently the open pit produces 11 Mtpa of ore. With open pit mining ceasing in mid 2011 development has begun on an underground sublevel cave mine to extend the life of the operation by another 12 years. When completed the open pit will be 530 m deep and 1.5 km in diameter. The orebody dips at approximately 45° and has been outlined a further 450 m below the base of the pit. This provides some challenges for the Ernest Henry underground mine which is designed to initially truck development and production ore from the end of the pit until a hoisting shaft is commissioned in 2013. Production will then increase to 5.0 Mtpa on its way to an ultimate rate of 6.0 Mtpa in 2016.This paper will focus on the capital development and infrastructure requirements for the underground mine. Areas covered include mine accesses, ore handling system, accommodations for the dip of the orebody, primary ventilation design, dewatering systems and selection of an underground workshop over surface only maintenance.Discussions include the complications arising due to the mine being located directly below a large open pit and the combination of first principle cost analysis and risk assessment which has been used to safely optimise the feasibility study designs.

Mar 21, 2011

By N Clarke, J Hunt, A Barros, L Keeney

The Gramalote orebody is a large low-grade gold deposit situated in the San Roque municipality, 124 km north-east of Medellin in Antioquia, Colombia. It is jointly owned by AngloGold Ashanti (AGA) and B2Gold and is currently in Feasibility Study phase. In 2013 AGA requested CRCORE to undertake a preliminary study of the potential application at Gramalote of pre-concentration by screening, part of the Grade Engineering suite. 160 samples of coarse assay rejects (-3 mm) were tested and showed one of the strongest responses seen worldwide to that time, suggesting that about 70% of the gold could be recovered into 40% of the mass. This was seen as potentially markedly improving the Gramalote economics. A large-scale testing program was implemented on site to follow up these results. A total of 18 samples of 17 t each were mined along a pre-existing exploration adit. A complex test flowsheet allowed size fractions to be generated from the as-received material as well as after crushing to 53, 23 and 3 mm, all from the same head sample. The procedures were designed after carrying out a heterogeneity study to measure sampling errors. The coarser size fractions were designed to study the effect of crushing on upgrade response and predict the response on open-pit run-of-mine ore. The finer size fractions were designed to investigate means of predicting the upgrade response across the orebody. The large-scale testing closely confirmed the average upgrade response as predicted from drill core assay rejects but found that only the -53 mm crushed material accurately predicted the upgrade response of individual samples. Ore geochemistry was able to usefully distinguish samples with good and poor response. A small study on drill core suggested that, for Gramalote, fine crushed material distinguishes vein associated and disseminated values but not other factors that control actual outcomes.

Nov 10, 2020

By J H. Park, R R. Kim, H S. Park, H J. Kim

This study focuses on the recovery of valuable metals, specifically silver (Ag) and palladium (Pd), from copper-containing sludge (with copper content less than 20 per cent) generated during PCB processing and from spent petrochemical catalysts used in vapour decomposition during oil refining processes. The present results indicate that an increase in the mixing ratio of alumina-based spent catalyst leads to a decrease in the recovery rate of Ag and Pd. The recovery rates for Ag and Pd range from 84 per cent to 96 per cent and 80 per cent to 98 per cent, respectively. This trend is attributed to the increased emulsification of copper droplets containing Ag and Pd in the slag. The emulsification is caused by the decrease in the settling velocity of the copper droplets due to the increased viscosity of the slag as well as by the decrease in the slag-metal interfacial tension due to an increase in sulfur content at higher mixing ratio of spent catalyst.

Jun 19, 2024

By Pati±o A

The Argentine pyroclastic loess arevulcanogenic deposits, which have their sources in the circumnpacific rim. The object of this work is to realize a de-tailed mineralogical characterization of this sediments, to use it like a geo logic outline which regiters discordance or similarity in them, The sampling zone extend from 714N-4125 to 622W-339S. The descriptions of these sediments was considered like basic, mesobasic or acid rocks. The basic sediments, looking like andesite-basaltic composition, are fill-ing the andean valley. The mesobasic one have a similar composition with a pyro-clastic dacite rock, and have been found in marshy pleistocene sediments in the intermountain valley and in the pampeana prairies. The acid ashed conform rhyoda-cite-rhyolite sediments which form the pampeana loess covers in the prairie.

Jan 1, 1990

By P Mugebe, M Yahyaei, M S. Kizil, R Low

This paper seeks to establish an empirical relationship between the impact of mining technological innovation implementation and a company’s market value. The company’s market value is represented by its stock price. In a bid to ascertain the relationship, a stock price prediction model is sought to be established using the firm-specific factors impacted by the implementation of innovative technology. This work is performed under the watch of the prevailing macroeconomic factors. The background anchors in the understanding that the difference between the economic status of a mineral deposit and its uneconomic status lies in the level of mining technological innovation most prevalent at a given time (Hartwick, Olewiler and Preuss, 1986; Wellmer and Scholz, 2017; Wright and Czelusta, 2003). This is derived from productivity improvement, resulting in sustainable profitability due to technological innovation. Unfortunately, there is not an adequately established relationship that links this technological innovation impact to the share price performance of the mineral commodity company.

Sep 1, 2024

By S M. Stewart

Industry, especially extractive industry, must now give serious attention to the impact its operations have on the natural environment and on the economic, social, and cultural context within which it operates.   While this obligation is statutorily managed, there has been a recent shift towards a culture of self responsibility. Industry is now talking about earning its ôsocial licence to operateö and the importance of maintaining the ôtriple bottom lineö, thus adding environmental and social performance to the usual financial criteria used to measure organisational performance. The social context within which companies operate has also become more sensitive with industry responding to a growing public expectation that it conduct itself in a way that strives for sustainability by operating and developing in a way that meets the needs of the present without compromising the ability of future generations to meet their own needs.   There are glowing accounts of industries engaging and collaborating with the communities within which they are based. In amongst these are also some disasters which result from cultural assumptions, industry created dependencies and the failure to attain community buy-in despite significant investment by the industry involved.   There are also remarkable stories of communities, and action groups within communities, being a significant catalyst for positive change of their natural, cultural and social environment. In amongst these stories there are also accounts of long and drawn out battles; adversarial situations where no one wins; a litany of mistrust, tricks and tactics, with the better resourced party ultimately achieving its primary objectives at the cost of the other (and at the cost of any potential fruitful, mutual relationships).   So what makes the difference in achieving the positive rather than negative outcomes? The answer lies in the way the outcomes are achieved. Building relationships based on good communication, respect for divergent views, mutual understanding, and the development of trust and empathy, makes it possible to identify shared goals and objectives that best meet the needs of all parties.   Research indicates the mining industry is making good progress in developing policy and commitment to community development and engagement but that, ætranslating commitments into improved practices at the site level remains one of the industryÆs toughest challengesÆ. (Australian Government - Community Engagement and Development Handbook October 2006 @ page 49.)   This paper considers the merits of a process of community collaboration and what it has to offer in terms of meeting that challenge.

Jan 1, 2007

By B McFadzean, N P. Lima, D A. Deglon

The reverse flotation of Itabirite iron ore is typically performed after a desliming step in which most of the sub-10 µm particles are removed. This is done to limit processing problems such as poor flotation recovery of SiO2 due to slime coatings and increased slurry viscosities, unmanageable froths and increased losses of hematite particles due to entrainment. However, the rejection of ultrafine particles contributes to large losses in iron recovery and may contribute to the instability of tailings dams. The aim of this study is to decouple the effects of ultrafine particles in the pulp and froth phases to better understand the processing capabilities of the fines fraction. The flotation test work was performed in a special-purpose continuously operated laboratory flotation cell that has a deep froth section to simulate plant-scale froth conditions. Five conditions of fines addition were investigated at three different froth heights and a solids concentration of 50 per cent. The behaviour of the pulp and the froth were decoupled using froth stability and froth recovery tests. This showed that, even though there is an exponential increase in froth stability at increasing fines quantities, the performance of the pulp has the overriding effect on the overall SiO2 recovery. Pulp zone, froth zone and overall SiO2 recoveries showed that overall recoveries increased by about 3.6 per cent for every 1 per cent decrease in fines content. This meant a large increase of 20 per cent in SiO2 recovery when going from undeslimed to deslimed feed. This was driven largely by increases in the pulp zone recoveries, which were about 4 per cent for every 1 per cent decrease in fines content. The froth recoveries, on the other hand, decreased by between 0.75 per cent and 2.5 per cent for every 1 per cent decrease in fines content, depending on froth height. This paper explores further insights into iron ore flotation processing at different slimes concentrations.

Aug 24, 2022

By I Canbulat, A Mcquillan

This paper presents a parametric analysis showing the impact of virgin in situ stresses on a shallow (less than 100 to 150 m) high slope in a jointed sedimentary rock environment. Slope stability is assessed at varying ratios of slope orientation and horizontal stresses. The results of this study indicate stress conditions should be included in stability assessments of excavated slopes, particularly where structure is orientated perpendicular to the direction of horizontal stress. Some consideration of stress state is applied in deep open cut pits (eg those with planned excavations of 400–1200 m) (Myrvang et al, 1993; Stacey et al, 2003; de Bruyn et al, 2014; Kozyrev et al, 2015). Dodd and Anderson (1972), Kalkani and Piteau (1976), Lee (1978), Coulthard et al (1992), Noorani et al (2011) have studied the effect or horizontal stress and its impact on slope stability, showing that tensile stresses tend to develop at the crest of the slope, with larger tensile zones for higher horizonal stresses and steeper slope angles (Stacey, 1970, 1973; Sjoberg, 2013). However, the consideration of virgin stresses on shallow slope stability is less frequent (Lynch et al, 2005; Dight, 2006; Lucas, 2006; Sjoberg, 2013). This has led many geotechnical engineers to believe the impact of virgin in situ stresses on open cut slope stability is minimal and not worth time or consideration in modelling, or their effects on slope stability are still poorly understood (Stacey et al, 2003; Sjoberg, 2013).

Nov 29, 2022

By V Ser, R Crosbie

To date, Anglo American Research Laboratories (AARL) has carried out several projects, based on the techniques developed in AMIRA International LimitedÆs (the mineral industries research association) AMIRA P9 project, to develop models for several Anglo Base Metals flotation plants. Further detailed analysis of the data which was generated has realised additional benefits: the various hydrodynamic measurements were useful in comparing cell operating parameters to literature sources, while the laboratory batch tests give an indication of plant recovery potential. A detailed cell by cell mass balance, which is a critical feature of the modelling process, is in its own right a valuable diagnostic tool. Several examples of how this can be used to highlight potential improvement areas in the plants are presented. The added understanding gained from sampling each cell is clear and this is shown to more than compensate for any necessary modifications needed to allow sampling to take place. The model fitting process generates an ore floatability distribution, which is used in the JK SimFloat simulation package to assess the effect of possible changes to each of the circuits. An example of an actual circuit change as a result of this approach is presented. The current limitations of and the potential improvements to the modelling process are also briefly discussed. Future models will be extended to include enhanced size and mineralogical information where the basic models suggest this has potential to improve understanding.

Jan 1, 2005