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By Stevens P

The Isa Mine of Mount Isa Mines Limited currently produces 5.4 million tonnes of copper ore and 3.3 million tonnes of silver, lead and zinc ore annually. Of this, 5.1 million tonnes of copper ore and 2.2 million tonnes of silver-lead-zinc ore is produced by sublevel open stoping. This paper summarises the capabilities, operating practices and problems encountered with current production drilling practices used to drill sublevel open stopes at Mount Isa.

Jan 1, 1982

By Boontanjai C, Boyapati ER

Reagents used for batch flotation tests were Aeroxanthate-343 & 350, Dow Z-6, & reagent-4037 (from Benambra) as copper collectors; Na2SiO3 & Na2S2O3as gangue depressants; lime & HCl as pH regulators; and pine oil & MIBC (methyl isobutyl carbinol) as flotation frothers. A Denver Sub A flotation cell of capacity 250 gms was used for the batch flotation experiments. Atomic absorption spectrophotometer was used for copper assays and microscopy for selectivity and liberation studies. Melbourne tap water was used throughout the experiments. Unless otherwise stated, the following parameters apply to the flotation experiments: flotation impeller speed - 1300 rpm, pulp density during flotation- 22%, reagents addition - in 4 stages, total conditioning time for collectors - 8 minutes, total flotation time- 9 minutes. A variable quantity of copper mineral collector according to the test in question was added, then conditioned the pulp for 2 minutes. The froth was removed by hand, scraping the full length of the cell at constant depth every 10 seconds. No frother is required for this copper tailing flotation. Four concentrates were collected after addition of collector and conditioning at 2,4,6 and 9 minutes. The pulp volume was maintained at a constant level to yield a constant froth depth.

Jan 1, 1990

By Wheatley MR

Answers to the questions "which rocks contain diamonds?" and "which indicator minerals should diamond explorers look for?" are no longer so easily obtained, now that diamonds are known to occur in lamproites and various types of lamprophyres, as well as their traditional source of kimberlites. One way of isolating those factors (host-rock"geochemistry, geographical or tectonic location, xenolith minerals, etc.) which are most critical in determining the diamond potential of a given pipe, is a detailed and critical re-examination of the huge volumes of accumulated data on kimberlites, lamproites and related rocks. A large analytical database to this end has been set up on an Apple Macintosh II microcomputer using the quasi-relational database management system 4th Dimension. Currently, it contains data for up to 90 major and trace elements, isotopic ratios and contained mineral compositions for some 4,000 rock specimens from all over the world. Many experiences in setting up this database are probably relevant to other geologists setting up their own systems: they include determining the relationships between data items; the advantages of codes over free text in representing categorical variables such as rock types; the need for rigorous error trapping and data validation; and the problem of missing data values and ambiguities thereof. The working system is now being used in a rigorous statistical assessment of the criteria which distinguish diamondiferous from non-diamondiferous rocks.

Jan 1, 1989

By N Arrys, A Jani, S Shahin

Optimising pit slope stability and reducing strip ratio of a mining operation are two key tasks in geotechnical engineering. With a growing demand for minerals and an increasing cost associated with extraction, companies are constantly re-evaluating the viability of mineral deposits and challenging their geological understanding. Within Rio Tinto Iron Ore (RTIO), the Structural Geology (SG) team investigate and collect critical data, such as point based orientations, mapping and geological inferences from adjacent pits to remodel deposits where previous interpretations have failed to account for structurally controlled slope failures. This work outlines the key methods utilised by the Structural Geology team which form the foundations of informed orebody knowledge and subsequent geotechnical design recommendations. This publication utilises the results from a recent analysis to highlight the benefits of this methodology and how it has impacted the economics of an operation through optimisation of a pit wall ‘cutback’ and crest relocation.

Sep 1, 2024

By F C. D Michelin

As mines get deeper, the critical underground temperature limits will be exceeded, and an increasing number of mines will need to implement, expand or modify cooling systems. Surface cooling plants have many advantages over underground cooling such as efficient heat rejection, and lower relative capital cost; however the delivery of cooling through long underground distances can result in lost refrigeration capacity before the chilled air reaches the areas it is needed most. Refrigeration plants are therefore often overdesigned in size and capacity to compensate for underground losses.More mines are now utilising real-time monitoring and automated control of ventilation airflow and fan systems to ensure the conditions underground are safe and productive, and power consumption is efficiently managed. There may be significant opportunities to extend ventilation monitoring and control into the refrigeration delivery and control system.Energy reduction is an effective way to reduce costs and CO2 emissions, which is an increasingly important part of corporate governance. More efficient refrigeration control is a further step toward reducing energy consumption. This paper looks at an added step in how real-time monitoring can assist in controlling the output and chilled air delivery of a cooling plant. The requirements, implementation, benefits and challenges will be discussed.

Oct 12, 2022

By J A. Wells, K G. Thomas, R F. Dewhirst

"One of the contributing factors to the extreme cost escalation in the first decade of the 21st century was the increase in the amount and cost of engineering work that went into studies and projects. Various reasons for this were identified, including unsatisfactory productivity due to a shortage of experienced/qualified engineers, the increased complexity and infrastructure requirements of many projects due to location, metallurgy that is more challenging and increasing environmental and social requirements. These conditions often led to unsatisfactory project results in terms of cost and schedule blowouts and created a loss of confidence – both internally and externally – in the industry’s ability to complete projects on time and on budget.Technical fundamentals aside, the experience and effectiveness of project teams has had, and continues to have, a major impact on project cost, schedule and ramp-up to nameplate capacity and operating parameters. There are unfortunately too many examples of where project teams have not been as effective as they could or should have been, all to the ultimate detriment of the project.Using the authors’ extensive experience on both owner’s and engineer’s teams, this paper discusses some of the main reasons for suboptimal team, and hence project, performance and offers thoughts on how best to build and maintain project teams. The analysis and conclusions drawn are built around the Tuckman model of group development known as ‘forming-storming-norming-performing’, which was first proposed some 50 years ago. Given the importance of good teamwork to project success, understanding how project teams grow and become efficient and productive is an essential part of good project management that should receive more attention.CITATION:Dewhirst, R F, Thomas, K G and Wells, J A, 2016. Building and maintaining effective project teams, in Proceedings Project Evaluation 2016, pp 38–48 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By B Taylor

Although the underground mining environment is arguably safer now than at any time in history, as underground mining operations across the globe increase in-depth, magnitude, and complexity, protecting workers from harm becomes increasingly challenging. In deep, stressed, seismic mines the development face is one of the most hazardous work areas. The active face is usually the furthest extent of the underground workings, so ventilation can be difficult to maintain, exposing workers to high temperature and humidity while working on foot and doing manual labour. While mechanisation has made many tasks easier in modern times, the reality of underground mining is that development charge-up workers still spend long periods directly exposed hazards at the face. In 2019, Orica and Epiroc partnered to co-develop the world’s first fully mechanised development charging unit using fully wireless initiation, called Avatel™. Built on Epiroc’s M2 Boomer carrier platform, the system is designed to allow one person to charge a development face from the safety of a fully enclosed cabin, thereby reducing exposure to hazards at the face. The system was prototyped in Europe before entering commercial introduction in 2022. This paper reviews earlier attempts to mechanise underground charge-up and describes the development journey and engineering challenges of building a mechanised development charging machine.

Mar 29, 2023

By Colquhoun L

Flooding velocities were measured in a laboratory column (96 mm 4) provided with both bottom and side air entry Packings used were 6 mm glass rings and spheres and -16 +8 mm coke. Results showed that when air was introduced through side nozzles flooding velocities were much higher than those obtained when air was introduced at the bottom of the column. Significance of the results and application to blast furnace flooding is discussed from the viewpoint of assymmetric gas flow.

Jan 1, 1975

The introduction ofa submerged entry tundish nozzle incorporating a cylindrical internal space for argon distribution to its inner bore slab is described. In co-operation with the refractory supplier, four major phases of nozzle development have been undertaken. Problems as well as successes are outlined.Significant reduction in alumina clogging ofnozzles has been achieved along with a decrease in nozzle consumption, using resin bonded alumina graphite with up to 4 different materials "zoned" to give resistance to thermal shock, gas leakage, and erosion.

Jan 1, 1985

Coal losses and dilution are among a coal mine operators everyday problems. These losses and unwelcome additions are generated primar- ily by the stripping operation and secondly by the coal mining opera- tion. Losses in yield due to preparation plant efficiency are a separate issue although they may be related to the coal mining operation. The losses and dilution can be traced to the following operations: (A) Overburden or Interburden Removal (1) Removal of coal edge by blasting operations. (2) Removal of top of seam by drilling/blasting. (3) Removal of top of seam by stripping equipment. (4) Removal of coal edges by stripping equipment. (5) Dilution due to stripping equipment. (B) Coal Mining (for the case where seams are ripped rather than shot) (1) Coal rib losses. (2) Coal rib dilution. (3) Coal left in floor. (4) Coal left in fault areas. (5) Floor material picked up whilst loading. (6) Spoil material picked up. (7) Spoil material from poor surface clean up. (8) Top of coal losses from final clean up. (9) Dilution from ripping too deep, i.e. into floor below seam. (10) Dilution from interseam parting. The losses apply to both the single seam and multi seam oper- ations although they are more pronounced in the multi seam mines than in a single seam mine due to the position of the coal which is lost. For example in the multi seam case the top seam coal edge loss is final. There is little chance of recovery with the subsequent pass even if the extra rehandle is done. However conversely the lower seam is relatively easy to locate as it has nowhere to go being contained by the lowwall bench.

Jan 1, 1988

By R Terracciano, J Schneider

Willemite (Zn2SiO4) is one of the main zinc carriers in several Neoproterozoic carbonate-hosted non-sulfide deposits ofNamibia and Zambia. Willemite commonly replaces sphalerite, but it may also replace the carbonate host rocks. Fluid inclusions, cathodoluminescence petrography and trace element geochemistry are crucial to distinguish between hypogene, high temperature and low temperature (possibly) supergene willemites. A global period of willemite mineralisation, extending from Cambrian to Lower Ordovician has been proposed for the southern hemisphere. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By Browner R, Kyle J

The adsorption of gold cyanide by the weak base ion exchange resins, PAZ-4¦ and Duolite A-7C, the neutral polymeric adsorbent, Amberlite XAD7¦, and the strong base resins, PAZ-8~a and IRA-400 have been studied in both low and high salinity waters, and their performance compared with activated carbon. A systematic study has also been made of the effect of different ions (Na+, Cat+, Mgt+, Cl', SO4) ) on the gold adsorption capacity and kinetics of these resins. The results indicate that, contrary to popular belief, the ion exchange resin, can perform effectively in highly saline environments. The performance of the neutral polymeric adsorbent im- proves with increasing salinity but cannot match the performance of the ion-exchange resins.

Jan 1, 1991

By Warren R. P

When the original Mount Gunson joint venture, between CSR and United Uranium ceased operations in December 1971, an intensive ex- ploration campaign was launched to prospect for more ore in the Mount Gunson region. This campaign resulted in the discovery of the Cattle Grid deposit. A comprehensive sampling programme proved the existence of 4.6 million tonnes of ore, at a mean grade of 2.4% Cu, calculated at a 1.0% Cu cut-off. The planning and development programme that followed this discovery included not only the mining and metallurgical aspects of the exploration of the deposit, but also the en- vironmental aspects. Preliminary work included data collection with respect to meteorology, soil types, and existing flora and fauna.

Jan 1, 1976

By M Fritz, B Ziegelaar

"For moisture samples, the International Standard for iron ore sampling states the following: Moisture samples shall be processed as soon as possible and test portions weighed immediately. If this is not possible, samples shall be stored in non-absorbent airtight containers with a minimum of free air space to minimise any change in moisture content, but should be prepared without delay. ISO 3082 (2009)Prescribing what to do is of course easy. Putting it in practice is, however, a little more problematic.The iron ore industry has seen quite some changes in the last ten to 15 years, such as: a large increase in the volume of seaborne trade new ore types and blends coming onto the market new mines, processing plants and port facilities producing more and loading faster an increase in wet processed ore products a dramatic rise and then equally dramatic fall in the iron ore price followed by a recent recovery.All of the above have had an effect on sampling facilities. The large increase in volume coupled with ambitions such as labour efficiency, safer operations and higher precision has driven the installation and retrofitting of automated sampling and robotic sampling preparation plants in order to keep up with increased quality control.Designers of sampling facilities are invariably instructed to build plants that comply with ISO 3082. In general this means that the plants are compliant in respect of the number of primary increments, gross sample masses and sample division rules. The clause at the beginning of this abstract is mostly overlooked as it only appears in a section (4.1) describing the basic requirements of a sampling system.An error of 0.1 per cent in moisture changes the value of 1 Mt of iron ore at US$50/t by US$50 000. At 700 Mt/a of Australian iron ore exports, this is US$35 M. Frequently, errors from 0.5 to 1 per cent in moisture measurements are encountered.In comparison an error of 0.1 per cent Fe is US$0.081 (US$50/t and 62 per cent Fe base) per tonne, that is US$81 000 per Mt or about US$51 M for the same Australian annual iron ore exports.It is somewhat mystifying that we in the ISO Technical committees spend extraordinary energy (= money and time) on improving measurement techniques, whilst the big costs are in sampling errors. This is particularly true for moisture measurement. Our paper quantifies some of the sources of moisture measurements errors and suggests mitigating actions.CITATION:Ziegelaar, B and Fritz, M, 2017. Sampling for the percentage moisture in the iron ore industry, in Proceedings Eighth World Conference on Sampling and Blending, pp 271–274 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

May 9, 2017

By F Butler, G E. Batley, A C. Hogan, A R. Butler

The ANZECC/ARMCANZ (2000) Water Quality Guidelines (the Guidelines) are the primary reference used in Australia and New Zealand for managing and regulating water quality. For most mining operations in Queensland, the environmental authority (EA – licence) incorporates the national default guideline values (GVs) for ecosystem protection as trigger levels (TLs). Exceedances of TLs ‘trigger’ further investigation and reporting. A review of the surface water compliance history at a metalliferous mine in North West Queensland identified minor exceedances of the cobalt GV as a common trigger for investigation and compliance reporting.The reliability of GVs is dependent on the availability and quality of ecotoxicology data for the relevant contaminant. The current national default GV for cobalt of 1.4 µg/L is classified as a low reliability GV due to the lack of available data at the time it was derived (ANZECC/ARMCANZ, 2000).The Guidelines are presently being revised and the toxicant GVs will be available as a set of web-based values and associated technical briefs. The new platform will enable the timely revision of existing GVs and inclusion of GVs for additional toxicants. Cobalt was considered a priority toxicant for the Guidelines’ revision, but was not included in the revision process.A preliminary review of the international literature indicated that at least 15 additional chronic cobalt toxicity studies had been published since 2000, sufficient to derive a high reliability cobalt GV using the protocols developed for the revision of the Guidelines (Batley et al, 2014; Warne et al, 2015). This presented an opportunity to improve environmental management by increasing the reliability of the performance measure.CITATION:Hogan, A C, Butler, A R, Butler, F and Batley, G E, 2016. Derivation of high reliability water quality guideline values for cobalt in freshwaters – improving water quality guidelines for better water quality compliance management in mining, in Proceedings Life-of-Mine 2016 Conference , pp 205–208 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By T Walsh, S R. Mudnuru

The development of lithium-ion batteries, coupled with the global trend towards electrification of transportation, has led to a dramatic increase in the demand for lithium. The production of lithium from hard rock ores is increasing, and flotation has proved to be an effective means for the beneficiation of many pegmatitic lithium ores. Clariant Mining Solutions has developed a range of novel collectors for the flotation of spodumene and other lithium ores, and this paper presents examples of some of the most recent developments. Fatty acids are the typical collectors for lithium flotation, however the grade and recovery achieved with these collectors is often below the desired level. There are also some significant drawbacks associated with the use of fatty acid collectors, such as the formation of calcium soaps which give rise to filtration problems and the need for acid washing. Several FLOTINOR products have been developed as alternatives to fatty acids. These products offer equivalent or better metallurgical performance at significantly lower dosages than fatty acids. This offers benefits to the flotation circuit as well as potentially reducing the issues associated with downstream processing of the concentrate.

Aug 24, 2022

The Martha Mine is an open cut operation situated in the midst of Waihi town which has been operating since 1987. Since then it has produced some 700,000 ounces (oz) of gold and 4,000,000 oz of silver from an epithermal vein system. It was previously worked by underground methods from 1880 to 1952 to a depth of 600 m producing 5 million ounces (Moz) of gold and 30 Moz of silver. The licensed reserves are scheduled to be mined out early in the year 2001. An additional economic resource of over 750,000 oz of gold has been identified which can be accessed by deepening the pit a further 50 m along the main Martha vein. This would extend the mine life to the year 2007. Applications were lodged on 4 July 1997 for the necessary resource consents, discharge permits and variations for the current Mining Licence conditions. The extension project requires approval from the District Council, Regional Council and the Ministry of Commerce. The consent and permitting process is extensive because of the urban setting of the mine. An approach to keep the extension as similar as possible to the current operations was adopted to give the community and authority confidence in the proposed extension. This paper summarises the extension detail and the permitting requirements it has had to address despite the extension being "more of the same". The permitting process has been exhaustive with little recognition of the standards already achieved in protecting the environment which are recognised worldwide.

Jan 1, 1997

Titanium tetrachloride may be reduced to trichloride with hydrogen on a hot tungsten filament and other hot: surfaces. The effect of temperature, time and size of t.he filament on the rate of reaction has been studied. A laboratory unit for preparing a few pounds of trichloride at a time is described. The yield of trichloride is 2·2 - 2·4 gm/sq. cm. of hot surface/hour at 1,000°C. and the energy requirement 3'5-4 kWh/pound of trichloride produced.'INTRODUCTIONThe lower chlorides of titanium (titanium tri- and dichlorides) are amenable to electrolysis, being electrovalent in nature. Furthermore, relative to other oxygen-free titanium salts, they are easy to prepare in a pure state and their use has been investigated to prepare titanium. The experimentaJ work described in this paper deals with the preparation of titanium trichloride by reduction of titanium tetrachloride with hydrogen on hot surfaces.REDUCING AGENTS FOR TITANIUM TETRACHLORIDEThe free energy diagram (Fig. 1) for the formation of chlorides suggests that titanium' tetrachloride may be reduced to trichloride by various reducing agents such as aluminium, zinc, arsenic, antimony, tin, mercury, silver, hydrogen, sodium, potassium and magnesium. Ruff and Neumann (1923), Thorpe (1885) , Billy and Brasseur (1935) and Seurbert and Schmidt (1892) used various metals to reduce tetrachloride to trichloride and found that the yields were invariably low and the products difficult to separate.Besides the metallic reducing agents, hydrogen may also be used to reduce titanium tetrachloride to trichloride.Goerges and Stahler (1909) obtained a deposit of violet...

Jan 1, 1956

By Moorrees C

Tests show how that temperature and rate of sparging to remove carbon dioxide determine the rate of precipitation and the chemical and physical properties of hydrated magnesium carbonates precipitated from clarified magnesium bicarbonate liquors derived from crude magnesia. At temperatures above 55°C the product is largely in the form ofhydromagnesite, Mg5(C03)4(OH)2.4H2O Between I5°C and 55°C the major product is nesquehonite, MgCO3·3H2O, although partial hydromagnesite precipitation can be induced by a high rate of aeration.As a result of the reduced time required to bring about greater than 95 per cent magnesium precipitation, the higher MgO content of the product, the ease of product recovery from the precipitation vessel, and the lower energy requirement for thermal decomposition of the precipitate to magnesia, it is preferable to precipitate hydromagnesite rather than nesquehonite. Moreover, the magnesia produced from hydromagnesite is somewhat more reactive than that formed from nesquehonite.Using precipitate calcination temperatures less than 1000°C, the chemical reactivities of the magnesias formed from both precipitates are greater than those of the crude magnesias derived from Savage River magnesite itself. The magnesias would be suitable for most uses developed for caustic-calcined magnesia. However, for refractory brick manufacture, it would be necessary to briquelle the caustic-calcined magnesia. adjust the CaO and SiO2 contents and sinter at temperatures in excess of 1600°C. This would bring about an increase in the bulk density and induce the appropriate chemical bonding reactions.Dead-burned magnesia produced from Savage River magnesite by the calcination/carbon dioxide route would have very low B2O3 contents, typically less than 0.0001 per cent.

Jan 1, 1985

By Baker G

Chromite was recorded among the rare minerals in the natural beach sand concentrates on the coast of Northern New South Wales by Whitworth(l) in 1931, and the commercial production of zircon and rutile from these beach sands has yielded concentrates of ilmenite with small amounts of chromium. The chromite is a detrimental impurity in the utilisation of the ilmenite, and the difficulties that attend the separation of the small amount of chromite from the ilmunite have raised suggestions from time to time that chromite occurs with ilmenite in composite grains. The absence of such composite grains and the nature of the chromite grains has been indicated by the following mineragraphic examination of magnetic concentrates containing chromite which were prepared by the C.S.I.R. Ore Dressing Laboratory, Melbourne University, from ilmenite concentrates from beach sands at Norrie's Head, County Rous, New South Wales and Stradbroke Island, Queensland.The magnetic concentrates from each locality are divided into five fractions, and the No. 1 concentrate is the most highly magnetic and the tailing the least magnetic. Chromium assays as determined by the Ore Dressing Laboratory are as follows:-

Jan 1, 1948