Search Documents

By Q Shu, T Deng, B Yan, B Song, D Wang

In view of the lack of phase equilibria data of vanadium-bearing oxide system and the desirability of them for design or optimisation of vanadium extraction process, the phase equilibria relationships of V2O3-FeO-SiO2-CaO(15 mass per cent) system were determined experimentally and then an isothermal section phase diagram of this system was constructed. Totally, 81 samples of different composition were equilibrated at 1623 K for 48 hours in iron crucible under Ar atmosphere. The equilibrated samples were quenched quickly in cold water, and then the phase constituents of all the samples were identified by X-ray diffraction (XRD) combined with electron probe microanalysis (EPMA) measurements.

Aug 21, 2024

By L Blackwell

Strategic mine scheduling is an industry best practice for increasing the long-term value of mining operations and supply chains. The application of optimisation technology such as mixed integer linear programming (MILP) is able to achieve a mathematically optimal result for a given scheduling model. Such a model will typically define the available source material, processing options and desired constraints for accessing and processing the material. Most strategic scheduling models, however, do not include a sufficiently detailed model of capital expenditure options related to capacity expansion.Typical strategic schedule models do not include important capital expenditure features such as capacity decay or expiration (limited lifespan of trucks), precedence relationships over time (rail construction before a new plant or non-linear expansions due to economies of scale) or mutually exclusive option sets (choices of plant size). By not including these features, a strategic mine scheduling model for a capital-sensitive operation is unable to be optimised to deliver maximum value or profitability.This paper presents several results of MILP optimisation using advanced capital expenditure modelling for mining operations and supply chains. Results of the study demonstrate that optimising capital expenditure at the same time as optimising the mining schedule allows for minimisation of capital purchasing, optimal timing for those purchases and optimal scheduling around them. Overall, this results in an increase in net present value.CITATION:Blackwell, L, 2014. Capital expenditure modelling for strategic mine scheduling, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 315–322 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By G Clarke

Commissioning of the Cannington processing plant began in October 1997. The nameplate capacity (of 1.55 million tonnes of ore per annum) was achieved relatively quickly. Since then (like many mines) the operation has strived to increase throughput and improve valuable metal recoveries, to offset declining head grades and lift the value of the operation. The processing plant now has the capability of treating over 3.2 million tonnes of ore per annum and in financial year 2005/06 the combined concentrate production exceeded 600 000 wet tonnes, approximately 80 per cent above concentrate output in the first full year of operation (at the design feed rate). This improved performance was achieved by making changes and additions to each of the major unit processes û primary grinding, flotation, leaching, filtering and paste fill preparation. The changes have included: adding a fines flotation circuit, expanding the grinding circuit, adding a pebble crusher, switching from continuous to batch leaching, building paste conveyors and decommissioning the column flotation cleaning circuits. This paper reviews these changes, outlines the current operating practices and discusses the challenges or opportunities that remain.

Jan 1, 2007

Avoca Resources LimitedÆs Higginsville Gold Project has a resource base of over 1 300 000 oz of gold. The Trident underground mine, which forms the basis of the project development, has a resource base of 927 000 oz of gold. Avoca is building the Higginsville Gold Project based on a minimum ten year vision, producing over 150 000 oz per annum. The project development has taken less than three years from the Trident discovery hole in October 2004 to the first ore production in June 2007. This paper discusses the background work associated with the development of the Trident underground mine in a difficult period for new project development in Western Australia. The resources boom, led by the iron ore industry in the Western Australian Pilbara region, is creating cost pressures and, combined with a lack of people and equipment, is placing cost and timing stress on a small developing project. Avoca Resources has developed a project execution management strategy aimed at mitigating cost blow outs and schedule delays.

Jan 1, 2008

By S O. Hille

Modern remote mining operations in Australia are more commonly trending towards fly-in/fly-out (FIFO) sites. This trend is driven by numerous factors including increased business centralisation, reduction in operating costs, and a desire to live in coastal cities that offer closer family networks and a greater diversity of facilities. Consequently, the resource development industry has had to adapt. When WMCÆs Mount Keith Nickel Operation commenced operations in 1994, it was developed as FIFO for its entire workforce. Since then, there have been several permutations of rosters within a 21 day compressed work cycle including the 14/7 cycle. This paper discusses a case study of the change in management process to the 9/5 work cycle focusing on minimising fatigue in the workplace. It includes the discussion of the business case, employee reaction and the practical application. The impact of the best practice change after 18 months is discussed.

Jan 1, 2002

By A M. Suchowerska, J P. Carter, J P. Hambleton

"In order to effectively predict the roof collapse of underground openings using continuum models, it is imperative that a realistic failure criterion is used to represent the rock mass. However, for coal mining operations, there is still uncertainty as to the appropriate failure criterion that should be used for the coal measure strata. This study compares stability numbers and collapse mechanisms for a rectangular underground opening predicted based on three commonly used failure criteria: the standard Mohr-Coulomb, Mohr-Coulomb with a tension cut-off and Hoek-Brown. Three methods of analysis are considered: an analytical upper bound method an upper and lower bound finite element formulation the displacement finite element method.The theoretical results are also compared with field measurements of subsidence above longwall coal mining. For the standard Mohr-Coulomb failure criterion, the friction angle governs the shape of the collapse mechanism, and the so-called critical width (the cavity width above which failures extend to the ground surface) ascertained from field observations in the New South Wales coalfields corresponds to a friction angle of approximately 30°. On the other hand, predictions obtained based on the Hoek-Brown failure criterion consistently overestimate the critical width. The results also show that tensile failure governs the stability of the cavity and shape of the collapse mechanism when a tension cut-off is introduced for the Mohr-Coulomb yield criterion.CITATION:Suchowerska, A M, Hambleton, J P and Carter, J P, 2014. Prediction of roof collapse for rectangular underground openings, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference, pp 367–374 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 5, 2014

By P Yß±ez, G Ferguson

The El Teniente mine produces more than 340 000 tonnes of fine copper per year from an industrial complex of underground mine, concentrator and smelter. Mass caving methods are employed to deliver approximately 95 000 tpd of ore to the mill, from a number of sectors underground, each sector being in effect a large-scale mine in its own right. This mining activity has faced challenges over the course of the last century such as:the capacity of the underground mine has been expanded to maintain and increase output of fine copper; the increasing size of the ore fragmentation forced to change the mining method to achieve the high productivity and profitability required in the business; and to modify the mining methods to continue mining at depth with safety. Fundamental activities in these mining methods, for the successful initiation of caving and subsequent draw, are:undercutting the base of the block or panel by blasting; and excavating of drawbells. The undercutting design evolves mainly on the height of the blasting to manage the change on ore fragmentation. The methodology move away from incorporating massive areas, typical of the block caving method, to a continuos blasting, typical of the panel caving method. Drawbell design changes on geometry, dimensions and sequence of excavation to deal with a corse ore fragmentation and the resolution of mining difficulties in the form of major rock bursts and collapses of production facilities. This paper focuses upon the evolution of the undercutting and drawbell design used at El Teniente mine and techniques under consideration to deal with future caving operations to provide the bulk of the daily production for the foreseeable future.

Jan 1, 2000

By C De-Vitry

In skewed distributions seen in many geochemical data sets, samples at the extreme ends of the distribution are often termed ‘outliers’. Samples considered as outliers can often make exploratory data analysis and resource estimation more difficult and less reliable. Such outlier samples may be legitimate because they are part of a natural high- or low-grade tail in the distribution. How these samples are identified and dealt with in resource estimation can often be a material issue for the Competent Person, particularly under the latest edition of the JORC Code (JORC, 2012). This paper discusses the identification and characterisation of outliers and high- and low-grade tails and proposes methods to deal with them in estimation.For dealing with outliers and high-grade tails ,very simple approaches, such as top-cutting through to more advanced geostatistical approaches, are discussed. The strengths and weaknesses of each approach are also outlined. Some examples of how the underlying geological understanding of a deposit influences the view of outliers and low-/high-grade tails is provided. The importance of documenting, communicating and challenging a given geological model is also discussed. Finally, some ideas for dealing with the uncertainty created by outliers are outlined.CITATION:De-Vitry, C, 2014. Identifying and dealing with outliers in resource estimation, in Proceedings Ninth International Mining Geology Conference 2014 , pp 159–168 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By K Haga, G Danha, A Shibayama, L L. Godirilwe

The hydrometallurgical separation and enrichment processes provide an effective way to selectively recover metals from relatively dilute multicomponent sulfuric acid leach solutions. The multicomponent leach solution utilised in this study contained 0.3 g/L Cu, 0.34 g/L Ni, 0.13 g/L Co, and 2.96 g/L Fe, which was obtained after high-pressure oxidative acid leaching (HPOAL) of the copper-nickel smelter slag. The solvent extraction (SX), precipitation, and xanthate complexation processes were employed to recover and upgrade Cu, Ni, and Co from the leach solution. Batch SX tests were carried out using a countercurrent two-stage mixer settler extraction column, and LIX 984N (10 per cent v/v) as a copper extractant. Fundamental parameters influencing the extraction process such as pH, mixing speed, H2SO4 concentration, and organic/aqueous (O/A) phase ratio were investigated. For copper enrichment in solution, a combination of two extraction stages and two stripping stages were employed. Copper was successively separated from Fe, Ni, and Co under optimised extraction conditions (pH 2, 400 rev/min, O/A 0.25, and 20 min contacting) and stripping conditions (175 g/L H2SO4, 400 rev/min, O/A 4, and 20 min contacting). About 97 per cent of copper was extracted with low co-extraction of Fe, Ni, and Co of about 5.90 per cent, 1.47 per cent, and 2.53 per cent, correspondingly. A final Cu-rich solution containing 23 g/L Cu was obtained with a very low Fe concentration of 0.05 g/L. Additionally, for iron removal from the Ni/Co raffinate solution, more than 99 per cent of iron was precipitated at pH 4 by the addition of a calcium carbonate (CaCO3) suspension, with low co-precipitation of nickel and cobalt of around 3.68 per cent and 2.27 per cent, respectively. Furthermore, about 83.6 per cent of nickel and 99.4 per cent cobalt were co-precipitated from the solution by potassium amyl xanthate (PAX) solution at pH 6. The Ni and Co xanthate complexes were thermally decomposed and recovered as cobalt oxide (CoO) and nickel sulfide (NiS) solids.

Aug 24, 2022

By B C. McLellan

The decline of ore grades on land, increasing demand and high prices for various minerals have led to an increased interest in mining the deep ocean sea floor. The potential deep ocean reserves are vast and in some circumstances the grades are high enough to consider mining. However, the consequences of such mining are as yet uncertain. This paper will present the results of a comparative assessment of life cycle impacts of deep ocean minerals. Two alternative extraction technologies from different deep ocean resource types were examined and key commodities are considered. Initial results indicate that the energy requirements will be higher than the average land-based resources, but may fall within the range of the deepest terrestrial mines.CITATION:McLellan, B C, 2015. Comparative life cycle impacts of deep ocean minerals and land-based counterparts, in Proceedings Third International Future Mining Conference, pp 253–260 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By R W. Shaw

The MTM Process targets treating lower grade and/or problem concentrates that are not attractive to smelters. The process has been developed at laboratory scale for copper and is based on a related development for zinc that has been extensively developed both in the laboratory and through pilot testing. The basis of the process is novel ammonia-ammonium chloride leach chemistry adapted to give high copper extraction whilst being selective over iron, arsenic and many other elements. The preferred flow sheet depends on location, especially infrastructure and utilities. These impact upon the leach and crystallisation stages more than copper reduction.

Aug 24, 2022

Most publicity about the copper industry nowa- days is focused on the adequacy of ore reserves and on excessive mining capacity. These concerns, stemming from public awareness of actual and poten- tial shortages and oversupplies, relate to production rather than consumption. Perhaps the reason for this one-sided view is that copper is thought of as a commodity which is conspicuously traded in world markets, rather than as one of many industrial materials that serve today's rapidly changing tech- nology. Copper differs from other widely traded com- modities in that its real cost of production has pro- gressively increased since World War II. The reasons for the increase are identifiable by analyzing operations in one of the world's large producing centres, the copper province of Arizona. Another respect in which copper differs from some other com- modities is that increases in demand occur less auto- matically in the case of copper than they tend to in commodities whose consumption is more directly related to population growth. The copper industry's current inability to generate and attract needed investment capital is attributable to these differences between copper and other com- modities; it suggests that the concept of copper purely as a commodity is outdated. The key to the problem is better integration between the activities of copper producers and users. Depending on cir- cumstances, integration takes various forms- for example, investment tied to long-term sales con- tracts between producers in developing countries and consumers overseas; common ownership of pro- ducing and manufacturing facilities in industrialized

Jan 1, 1978

By Andersen AK

As part of a research program sponsored by Continental Copper and Steel Industries, Inc. (cos), investigations have been conducted by the Colorado School of Mines Research Foundation, Inc. to study the effect of high current densities on electrolytic processes. The importance of high current densities has long been recognized, particularly in the deposition of copper, and the results of considerable research on the subject have been reported in recent years (19 29 39). This is not surprising because, besides plant capacity, current density is the other major factor which will determine the process economics. In the production of electrolytic copper, current efficiency, steam consumption, number of cells, building area, metal inventory, cathode purity, and power consumption are all affected by current density. The ability to maintain a high current efficiency and satisfactory cathode purity while increasing the current density to twice or three times that commonly practiced could result in considerable saving of capital investment and reduce the operating cost per ton of metal produced. The optimum current density i.e., that current density of which production cost would be at a minimum, can be established from an analysis of the various inter- relating factors (49 59). A review of.all operating electrolytic plants (electrowinning and electrorefining) will indicate that most of these plants are operating at 50% or less of the optimum current density (6). One of the reasons for not using the optimum current density may be attributed to the fact that conventional electrolytic tank- house equipment does not perform satisfactorily at high current density operations. Various investigators (19 79 8) have attempted to overcome this limitation by modifying the design of the electrolytic cell, virtually unchanged since it was first introduced in the late 1800's. Previously, these attempts have not resulted in,a cell design suitable for commercial application. However, recently, a cell has been designed which performs efficiently under such conditions. This is a CCS development (patents applied for).

Jan 1, 1969

By Dunlop A. C

A brief study from the Mt. Bulga prospect com- pares the chemistry and mineralogy of different soil fractions and other materials to suggest a sequence of surficial metal dispersion from adjacent gossans, which may have relevance for geochemical exploration in semi-arid terrains. v v v v v JIV-- v v v v a o v o/ v v v v 1 v v lv ./v '' 1 v 16400N ..I v 1635014 v 1630014 .:1 ò.t SILURIAN sillstone " lelsic volcanic sillstone -sandstone ORDOVICIAN Eandesite o quartz float gossanò pits doOP Iv o shalt v _--'fault v 1---1 soil traverse v v v v 0 100 200 mm e Fig. I Local geology and location of soil traverses, Mt. Bulga (compiled from Chisholm, 1976). The Mt. Bulga prospect in central New South Wales is a small but well documented volcano- genic massive sulphide occurrence (450,000t of 0.8% Cu, 1.3% Pb, 5% Zn and 0.45 g/t Au) Cambrell and Kirk (1974), and Chisholm, (1976). Mineralization is localised near the interface of felsic pyroclastics with overlying silt- stones and along adjacent faults (Fig. 1). In this area with a Koeppen type cf6 climate, soils are thin and skeletal along ridges with thicker and better differentiated profiles with a colluvial component up to 2m thick developed

Jan 1, 1988

By P Benjamin, H Bohannan, C Farr

Geoffrey Blainey's historical account of the mining activity on the west coast of Tasmania, æThe Peaks of LyellÆ documents the changes over 130 years of activity in the region. Commissioned by the Mount Lyell Mining and Railway Company, emphasis is placed upon the development of the Mount Lyell Mine in Queenstown. Chapter 19 æWidening HorizonsÆ details the review the Mount Lyell Company undertook in 1904/05 to ensure the future of the operation, following the pessimistic outlook regarding diminishing reserves and poor grade ore. The analogies documented between the Mount Lyell Company at that time, and Gold Mines of Australia 90 years on are remarkable, with both companies demonstrating a commitment to the Mount Lyell area through active exploration, the proactive search for alternative technology and the recognition of the valuable human resource. As Blainey writes (Blainey, 1993), æwith its expanding chemical works, its huge Tasmanian mines, its railways and smelter, its coke works and its mine crusade, Mount Lyell was probably one of the nation's five great industrial companies in 1906 or 1907. This brief phase of industrial and mining expansion had its seed in the threat of extinction . . .Æ After a number of reprieves, the Mount Lyell mine did stop production in 1994, but that only provided an impetus for a review and rebirth.

Jan 1, 1998

By S Wellink, D Chalmers, D Adermann, C Martin

The practice of recording blasts for quality control purposes has been conducted for several decades. However, at the low frame rates of a standard video camera, essential data is frequently missed as it occurs when the shutter is closed between frames.The use of high-speed video for the research, development and monitoring of the performance of blasting procedures is a well proven but under-utilised practice.The recent development of low cost, easy to use high-speed digital cameras and user friendly software can deliver a capability into mine management as a day-to-day production tool that can greatly improve blasting performance and reduce costs.Digital high-speed video and image analysis software can accurately quantify each blast. Analysis of the images can facilitate the identification of causes of variance from design, geology changes, errors in blast practice and areas of poor performance. The use of high-speed video greatly enhances the audit and review processes so that future blast design can be quickly and appropriately modified to deliver improved blasting performance and reduced costs.The three videos demonstrate the differences between standard video and high-speed video and the detail that can be obtained from them. These videos of open cut blasts can be used to identify blast performance variances. Capturing images at 1000 frames per second allows the analysis on a millisecond timescale where detonator timings, fragmentation, venting, fume generation and flyrock can be accurately identified.CITATION:Adermann, D, Chalmers, D, Martin, C and Wellink, S, 2015. High-speed video – an essential blasting tool, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 471–476 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By D MacKay

The Mt Wright Project is located near the town of Ravenswood in North Queensland and is operated by Carpentaria Gold – a wholly owned subsidiary of Resolute Mining Limited. Underground Development of the current Mt Wright orebody commenced in June 2006 and the first production ore was brought to surface in June 2007. The orebody is a rhyolite pipe containing fine-grained disseminated gold in a granite host rock. Ground conditions tend to be good to excellent throughout development, with some minor deformation experienced when stope-sized excavations are formed. The mine commenced as a sublevel open stoping (SLOS) operation with the intent to utilise development waste to back fill isolated upper level stopes while developing to the bottom of the known orebody. The mine plan intended to commence production with a bottom-up primary/secondary stoping retreat through the main orebody utilising cemented fill. Some challenges were faced during the initial production phase that included:•Ongoing underground diamond drilling and updating of the block model resulted in some issues reconciling the grade control results to the resource model. This was primarily due to the high variability of grade which in turn caused difficulties in accurately identifying areas of low and high-grade.•The cost of establishing and operating a cemented fill plant to achieve the planned extraction sequence of the orebody had increased significantly beyond initial estimations.•Geotechnical conditions such as stress orientations, ground behavior and response to the forming of excavations learned through the mining of the upper level stopes were different to the assumptions made during the initial design.A number of in-house and external reviews of the mining method were completed which has resulted in a revised mining plan. This paper will summarise the challenges faced and the implementation of the mine plan to date.

Mar 21, 2011

Up to 80 per cent of the copper in a bornite ore can be quickly leached with percolating acidified ferric sulphate solutions. The upper limit for rapid copper extraction is set by the conversion of bornite to slowly dissolving chalcopyrite. The dissolution occurs in two stages: a rapid linear initial stage, followed by a slow, non-linear stage. The initial step is largely controlled by the rate of oxidant supply (Fe2(S04)3); temperature is not an important variable during the initial reaction. The second leaching stage is controlled by chemical and physical factors and is temperature dependent. The initial copper leaching rates are insensitive to both the concentration of the ferrous sulphate reaction product, and the sulphuric acid concentration.

Jan 1, 1973

By M E. Watson

Minimising dilution and ore loss is an important part of ensuring profitability of a gold mining operation. White Foil open pit gold deposit is a low-grade deposit and therefore managing ore quality is a high priority. Ground movement through blasting can displace ore and waste boundaries up to 10 m from their in situ location and therefore requires stringent ore movement monitoring and adjustment. There are currently only two options for monitoring blast movement – utilising visual targets (commonly lengths of polypipe) but this has widely been replaced by electronic blast movement monitors (or BMM). Regardless of the technology used, the basic principle is to compare the pre- and post-blast locations of the targets to determine the movement of the rock mass during blasting, which is then used to determine the final location of ore and waste boundaries.The Blast Movement Technologies (BMT) BMM system has been used at White Foil since June 2014. The system has been effective and reliable during that time; however, the annual cost of using the BMM system is greater than other monitoring alternatives. As such, the open pit geology team conducted a study comparing the BMM system against the conventional polypipe technique. The objective was to quantify the profit and loss that would occur based on the ore block transformations from both methods. Eight blasts were selected where polypipes were installed in additional holes adjacent to the BMM monitoring holes. The resulting movement vectors from the respective methods were used to create post-blast ore blocks by transforming the in situ ore blocks. While polypipe is a cheaper alternative, the BMM system tracks ore and waste boundaries more effectively resulting in better quality control, enhanced ability to minimise dilution and ore loss thus maximising profit. For these eight blasts, it is calculated that the BMM system resulted in A$664 978 extra profit through a reduction of ore loss. The total cost of a yearly BMM package was recovered in the first two blasts of this study. The primary reason for the difference is that polypipe had a poor recovery rate of 32 per cent compared with 92 per cent for BMM at White Foil. Therefore, the data used to transform the ore blocks was less representative, resulting in inaccurate post-blast ore block boundaries when using polypipe.CITATION:Watson, M E, 2017. Blast movement monitors or polypipe? A study into cost-effective blast movement monitoring at White Foil gold mine, Western Australia, in Proceedings Tenth International Mining Geology Conference 2017, pp 433–440 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

There are many compelling reasons why correct sampling schemes should be standard practice in the mining industry, yet there are numerous examples where poor sampling practices are known to exist in the business yet permitted to continue. It is not just technical issues that can be ascribed to the reasons for the continued use of incorrect methods. This paper proposes non-technical reasons why incorrect sampling practices continue, and identifies potential ways to overcome them.

Mar 1, 2010