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By J Kovacs

Underground development drill and blast practices have generally remained unchanged for decades. Historically, development optimisation has focused mainly on the application of perimeter control products in order to reduce overbreak, and efficiencies in development cycle times to increase advance rates. In today’s environment of ever increasing operating costs and lower ore grades, it has become even more critical to focus on the optimisation of drill and blast in development mining. It is a crucial component in ensuring mining schedules are maintained, but more importantly achieving the objective of getting to the orebody in the shortest possible time.This paper will focus on the development optimisation process used in a trial at Xstrata’s George Fisher Mine in North Queensland. Not only did the trial include the typical optimisation areas of charge loading practices, perimeter control methods, drill design standardisation and quality control processes, it also investigated the significance of delay accuracy with regards to perimeter control and drill design optimisation.One of the key measures of the trial was a comparative analysis between baseline development and development with the staged introduction of optimisation elements using 3D photogrammetry as a validation tool. A detailed cost analysis between the various stages was also a key measurable of the trial.The results of the work undertaken at George Fisher have shown that the accuracy of electronic detonators can produce significant benefits in development blasting. When combined with standard optimisation philosophies a substantial reduction in overbreak, ground support requirements and development cycle times can be achieved, whilst still being able to reduce the overall development operating costs.CITATION:Kovacs, J, 2014. Mine development optimisation – an evolutionary process, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 51–56 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

With the continued implementation of stricter limitations on the discharge of excess process water from all existing and future mining and metallurgical operations, the design and operation of the entire process water circuit must form an integral part of any total operational package. It is far better to æanticipate and circumvent the problemÆ rather than be forced into an expensive remediation program after the event. By far the greatest problem relates to the treatment and disposal of what is generically known as acid drainage. In simple terms, an acidic metal sulfate solution is generated by a series of chemical and biological reactions as soon as most sulfide minerals are exposed to air and water. Treatment of this solution by one or more of a wide range of chemical and physical options can involve substantial capital and operating costs, although there are recent processing options that yield saleable by-products, thereby reducing the financial liability of what is effectively a waste stream. This presentation provides an overview of the Australian situation compared with the rest of the world and outlines the basic features of a number of the more advanced passive and active acid drainage options.

Jan 1, 2004

The different electrowinning cells presently developed for recovery of gold from CIP eluates are compared and contrasted. The efficiency of operation for each cell is,discussed in terms of the electrochemistry of (a) gold deposition, and (b) packed bed electrodes. The advantages and problems associated with each cell design are presented and recommendations are made as to the best method of gold recovery.

Jan 1, 1982

By Y Durkheim, P Saunier, L Ameglio

"In the last decade Afitex developed the Draintube™ geocomposite, which provides simultaneous drainage and waterproofing functions. This new type of drain tubes planar geocomposites (DTPG) differs from other geocomposites as the drainage core is composed of multiple corrugated and perforated pipes instead of biaxial or triaxial nets. It is furthermore associated with needle-punch stitched layers of non-woven geotextiles, which act either as capillary mediums or as filters.In this paper, the structure of the Draintube™ drainage composite is presented along with its key properties and the drainage mechanism associated with its particular structure.The relevance of this kind of structure is then reviewed based on past and current laboratory bench evaluations and field installations for mining applications such as the covering of acid rock drainage (ARD) tailings for the Central Manitoba Mine (Canada) site-rehabilitation; and as a pregnant solution collection layer in heap leach pads.Some of the demonstrated critical advantages of Draintube™ in the mining industry are as follows: reduction of the thickness, hence lower volume of granular drain layers improvement of fluid and gas collection and reduction of the hydraulic load reduction of secondary collector network mechanical protection of the sealing membrane fast and economical installation of interlifts stability under extreme conditions (compression, temperature, pH) increased stability of entire covering system and reinforcement of protection of dykes filtration of the covered material customised drainage positive connection of the geocomposite to collector pipes enable leaks detection (using a conductive textile layer) with an electrical test.CITATION:Saunier, P, Ameglio, L and Durkheim, Y, 2015. Tubular drainage and lining geocomposite for mine tailings and heap leach pads, in Proceedings Tailings and Mine Waste Management for the 21st Century, pp 297–304 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 27, 2015

The Douglas mineral sands deposit is located 75 km north of Hamilton in western Victoria, Australia. The deposit was discovered in the late 1990s by Basin Minerals Limited and purchased by Iluka Resources Ltd in 2002. Prestrip mining commenced in December 2004, with ore mining commencing in August 2005. Douglas is the first of several projects being implemented by Iluka Resources Ltd in the Murray Basin, with all heavy mineral concentrate planned to be treated at the companyÆs mineral separation plant in Hamilton. The mineralisation at Douglas lies along the south-eastern margin of the Murray Basin. It is hosted by marine Pliocene Loxton-Parilla Sands and consists of three discrete deposits; Bondi Main, Bondi West and Bondi East. The mineralised sediments dip at a low angle to the west and lie unconformably beneath a veneer of top soil (50 - 100 mm) and subsoil (up to 600 mm) and between three to 12 m of overburden. The barren overburden, characterised by high clay content (<53 ¦m material) generally provides a stark contrast to the sandy ore, which is between 1 m (parts of Bondi East) and 15 m (Bondi Main) thick. Both overburden and ore are removed utilising standard dry mining techniques using both scraper-bulldozer and truck-excavator combinations. All ore is delivered to run-of-mine (ROM) stockpiles before being reclaimed by front end loader into the processing plant. Grade control at Douglas is based around visual dig control aided by high precision survey, which enables accurate reference to the resource drilling and block model data. Vertical excavator faces, inclined scraper faces plus regular test pits and trenches provide opportunities for in pit mapping and sampling. This data is used to refine not only the resource estimate for Douglas but also the drilling, interpretation and resource modelling methods used for similar deposits across the basin. The foundations of the geological reconciliation process at Douglas are the in pit surveys undertaken each time the mining fleet has completed building a ROM stockpile. These surveys and the subsequent interrogation of resource models enable robust estimations of the heavy mineral content of the stockpiles, which are subsequently used to predict the daily input grades into the plant during their reclamation. Reconciliation of this daily data is then undertaken at the end of each month against metallurgical production data and plant balances. Learnings and results from the reconciliation process are used to further refine subsequent resource models and modelling methods.

Jan 1, 2009

By Madgwick J. C, Ralph B. J

A method for the determination of microgram quantities of uranium in leachates from low grade uranium ores is described. Solubilized manium is purified by transfer to an organic solvent by a selective solvent extractionprocedure using tributyl phosphate, iso-octane, and aluminium nitrate. The organic phase is mixed with scintillation fiuors in toluene and the radioactive decay determined in a liquid scintillation counter. The method is sensitive and reproducible in the range 3-30 µg uranium.

Jan 1, 1978

Several factors contributing to the loss of fibre during treatment are a function of the paragenesis of the veins. The occurrence, of magnetite from the cap rock within the veins prevents complete fiberization. There is a marked similarity between these veins and those in the Koegas-Westerberg area of South Africa.INTRODUCTIONAn investigation of the mineralogy of the Wittenoom Gorge crocidolite veins was undertaken in the latter part of 1962 at the request of the Colonial Sugar Refining Co. Ltd. It was anticipated that such a study might reveal the cause or causes of the lack of recovery of some asbestos during beneficiation. Some interesting features of the mineralogy and paragenesis of the crocidolite veins become apparent, but it is emphasized that the investigation is far from complete, as the study did not extend to the field occurrence.The samples examined were selected from the mill and from the untreated ore.GEOLOGICAL SETTINGWittenoom Gorge is situated on the Fortescue River in the Hammersley Ranges of Western Australia and is one of several gorges in these ranges, on the sides of which 'crocidoIite asbestos is known to occur. The Hammersley, Ranges consist essentially of a series of quartzites, shales, ferruginous quartzites and dolomites. These' rocks are part of the Nullagine Formation (Proterozoic) and are usually either horizontal or gently folded. In some 'areas small beds of riebeckite as well as crocidolite are known to occur interbedded in the sequence.Riebeckite is a monoclinic amphibole, the formula of which may be stated as Na2Fe2"Fe2" (OH) 2Si8O22, and crocidolite is a fibrous variety of this mineral. This formula...

Jan 1, 1963

Laboratory scale flotation tests were done on mineral hematite and aspecular hematite ore using oleic acid and sodium oleate as collectors. The mineral hematite floated strongly in the neutral pH region, with an increased pH range of flotation at higher oleate additions. Concentrates with sufficient hematite grade to meet the paint pigment specification were produced using oleic acid and sodium oleate as hematite collectors on the specular hematite ore. Hematite recoveries of 70 per cent at 60 per cent Fe grade were obtained using stagewise roughing. The interaction between hematite and oleate was confirmed as chemisorption but the exact mechanism could not be determined, as two independent phenomena can be used to explain the fact that the pH of maximum grade increased with increasing oleate addition.

Jan 1, 1999

By Belcher C. B

A simple gravimetric procedure was developed for the rapid determination of carbon dioxide in coal mine roadway dust samples and the result is used for the subsequent calculation of incombustible matter contentaccording to the requirements of the Queensland Coal Mining Act. The carbon dioxide is determined through loss of mass by a semi-enclosed apparatus, following room-temper.ature hydrochloric acid attack on the sample.With a sample containing 36 per cent carbon dioxide, the achieved standard deviation (ls) of 0·3 per cent CO. is adequate for coal mine roadway dust analysis.This simple procedure enables relatively unskilled labour in mine laboratories, to analyze coal mine roadway dust samples in accordance with the Act. Some 50 analyses can be achieved per day compared with 8 by the Australian Standard Method for coal.

Jan 1, 1976

By S Kodate, Ö Aydan, Y Suda, J Tomiyama

Fracture zones are commonly found in the Earth’s crust. These zones may cause very severe engineering problems. Therefore, the formation and the assessment of the mechanical characteristics of these zones is of great concern for rock engineers. A new double shearing jig was used to study the formation of shear zones in rock under static and impact loading conditions using the device developed by the authors. A series of experiments were undertaken to investigate formation on the formation and characteristics of fracture zones in laboratory. Although actual fracture zones are more complicated, various tests give some insight view of the formation of fracture zones as well as some information on their mechanical behaviour under both dynamic conditions and static conditions. The authors report the outcomes of these experiments and discuss their implications in practice.

Nov 29, 2022

By Edwards A. B

A suite of specimens from the newly developed Black Star copper ore body at Mount Isa was made available for mineragraphic study by the Mount Isa Mines, Ltd. The specimens were selected as representative of the different phases of mineralisation found in the ore body, rather than with a view to furnishing a complete cross-section of it; and the examination has been carried out with a view to ascertaining (1) the nature, extent and association of the arsenic, antimony and possibly bismuth, minerals in the ore, (2) the mode of occurrence of silver in the ore, and (3) whether galena and sphalerite occur in minute forms well below the sIzes readily observed in hand specimens.Analyses of the January to June, 1944, mill head composites show that the proportions of the elements Ag, As, Sb and Bi in the ore are as follows:Ag 0.000013 = 0.35 oz./tonAs 0.024Sb 0:002Bi 0.0005The copper content of the mill heads ranges from 3.5% to 4.75%, the lead content from 0.03% to 0.08,% and the zinc content from 0.09% to 0.23%.MINERAL COMPOSITIONThe specimens range from massive sulphide ore, consisting of areas of chalcopyrite, pyrrhotite, and rarely sphalerite, from 1 to 3 cm. across, to fragments of extremely finely banded pyritic shale in which no minerals other than pyrite are visible. The gangue associated with the massive sulphides is chiefly dolomite, and sometimes white quartz. The pyritic shale fragments show evidence of shearing and faulting on a micro-scale, the fractures sometimes being filled with sulphides and vein minerals.The ore minerals found in the polished sections are pyrite, arsenopyrite, marcasite, sphalerite, chalcopyrite, valleriite, chalcostibite, galena, dyscrasite, jamesonite, magnetite, gold, graphite and rutile.Pyrite (FeS2)Pyrite occurs chiefly in two forms according to whether deposition took place along the bedding planes or along the intersecting faults and fractures. Deposition of pyrite along the bedding planes of dense, thinly banded shales ha,s produced a metasomatically altered shale in which the pyritic bands are from 0.02 to 0.03 mm. wide, and alternate with bands...

Jan 1, 1945

While the new Minister of Economic Development sends his apologies at being unable to speak at this Conference, I am delighted to present on his behalf. The Ministry of Economic Development is not only responsible for managing the Crown mineral estate, but also for developing initiatives and policies to promote regional economic development and for managing the GovernmentÆs broader economic development strategy. IÆd like to talk to you today about the critical links that need to exist between these three areas.   I am going to start with a question for all of you. What do these towns have in common? +        Waiuku, +        Thames, +        New Plymouth, +        Nelson, +        Greymouth, +        Arrowtown, +        Reefton, +        Palmerston, and +        Dunedin.   The answer is minerals. These towns were nearly all founded on the back of minerals and mining. In the case of Greymouth it was gold that brought the people to the mouth of the Grey River and it is coal that sustains the town.   In 1870 the town of Shortland had 20 000 people, 90 hotels and was twice the size of Auckland. We now know Shortland as Thames, and of course Auckland is considerably larger. One wonders whether the good folk of Shortland suffered from ætraffic jamsÆ with 90 pubs to navigate between. Gold mining in the Aorere River near Collingwood led early entrepreneurs to develop the land surrounding Nelson as a food basket to sustain the mining population. Nelson is still thriving on this legacy today. The town of Palmerston was founded in 1862 as a stopping point for gold miners heading into central Otago. The gold rush made Dunedin New ZealandÆs first highly industrialised city. Reefton on the West Coast was the first town in New Zealand to have electric lights and in the recent past we were wondering whoÆd be left to turn them off. New Plymouth, and Waiuku are still known as energy and mining centres.   By contrast once thriving towns like Capleston, Canvastown and Blackball are just names on a map now, and at the extreme you have places like Waiuta which has been reclaimed by the West Coast forest. Queenstown was built off the back of the gold rush, but by 1900 with the gold gone, only 190 people lived there yet Queenstown has managed to rebuild itself thanks to some other stunning natural assets. These examples help illustrate three key points that I am sure will each be extensively linked with our minerals and mining industries. First, NZÆs development and that of its regions has been, and continues to be, inextricably linked with our minerals and mining industries.   Second, things change. Sectors, regions and countries must continually adapt and improve if the are to avoid the fate of the Waiutas of this world. And third, the development challenges faced by NZ and its mining industry in the 21st century are vastly more complex than in the past. Governments and industry alike must balance and respond to a range of domestic and international environmental, cultural, economic and other interests and considerations. If you thought of your industry as æjust digging holes in the groundÆ then you may as well simply stick your head in one!

Jan 1, 2005

By G York

South African gold reserves extend to great depths. However, strategies for the mining of such deposits have changed only slightly over the past number of years. Regional support at depth is currently provided by rock pillars and backfill. Many problems have been experienced with these regional support practices at deeper levels. In this paper several alternative forms of regional support are described which include the use of concrete, the use of back area caving and confinement to strengthen pillars. These new concepts are supported by numerical and laboratory modelling and in situ results.

Jan 1, 1998

The notes from which this paper has been prepared were set down at the time of the author's departure from Australia in 1935. Mr. Frank Forman, Government Geologist of Western Australia, who has very kindly read the paper in manuscript, affirms that the views here set forth are now accepted by most geologists. Thus, Forman's recent presidential address before the Royal Society of Western Australia (1937) mentions sediments in the Kalgoorlie Series "including banded jaspers and jaspilites."While it may, therefore, be superfluous to belabour the question further at this time, Mr. Forman has encouraged the author to publish this paper as a summary or both past and present views.To those specially interested in the subject of the paper, a study of pertinent Plates attached to Western Australian Geological Survey Bulletin No. 71, 1917, is suggested.The type of rock which is variously called "jasper bar," jaspilite, or "ferruginous quartzite" is familiar to all mining men who have worked in the West Australian goldfields.In its typical form it is a "striped" rock consisting of alternate layers of white or pinkish silica with red to brown bands of iron-bearing silica.In the course of geological work in many parts of Western Australia I studied exposures of jasper bar and was repeatedly impressed with the similarity of much of the material to the sedimentary "banded iron formation" of Canada. It was, therefore, a surprise to learn that the jasper bars were not generally regarded in Australia as sedimentary horizons. It is true that Honman offered convincing evidence of the sedimentary origin of the jaspers...

Jan 1, 1939

By A Hekmat, R Castro, A Casali, R Gómez

Block caving is the most economic underground methods for excavating massive orebodies, due to the high productivity and low production costs. The success of block caving operations depends on the fragmentation and draw control as large blocks decrease the equipment efficiency, inhibit the material flow and may lead to expensive secondary blasting. Even though ore handling system design, as well as overall economic results, both critically rely on secondary fragmentation, this parameter continues to be one of the least understood issues in the caving operations.This research focuses on the experimental study of secondary fragmentation, considering the impact of vertical pressures and material flow. Experiments using a load-haul-dump extraction system were conducted under laboratory conditions to quantify the influence of pressure and particle size on secondary fragmentation. Results demonstrate that increasing the vertical pressure (simulating deeper conditions) leads to higher fragmentation (smaller particle size) and greater fines generation during draw. The experimental results were applied to calibrate the developed mathematical model based on kinetic matrix. The acceptable accordance between the comminution model results and the reality showed that this method is convenient in predicting the secondary fragmentation in block caving.CITATION:Castro, R, Gómez, R, Casali, A and Hekmat, A, 2016. Experimental and comminution model framework for secondary fragmentation prediction in block caving, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 175–182 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

The purpose of this paper is to describe briefly the clean-up procedure adopted at the treatment plant of Paringa Mining & Exploration Co. Ltd. at Kalgoorlie, Western Australia.A clean-up is carried out at the end of each four-weekly period, and all figures subsequently quoted are taken from a summary of the results of the eight periods ending 8th April, 1941.STRAKING AND AMALGAMATIONOf the total gold won 22· 77 per cent. is recovered by straking and amalgamation.The discharges of both the primary and secondary ball mills are pumped over a common set of five ten feet long by three feet wide straking tables, set at an angle of 10 degrees, before passing to the 14 ft. diameter by 30 ft. by 8 ft. Dorr bowl classifier.This classifier is in closed circuit with both of the ball mills, hence the whole of the circulating load of the fine grinding circuit, which approximates to 800 per cent., is required to pass over the straking tables. For convenience in handling, corduroy cloths are used in lengths of 5 feet, and are picked up and replaced by clean cloths at four-hourly intervals. The avaHable straking area provided is, therefore, 900 square feet, or approximately 3·30 square feet per original ton per 24 hours. The density of the pulp passing over the tables is about 54 per cent. solids, the area provided per ton of pulp per 24 hours being approximately o· 2() square feet. Washing of the corduroy cloths is carried out on the day shift only, about 800 lb. of strake concentrate being obtained daily.This concentrate is sluiced from the washing trough on the elevated straking floor to the 4 ft. by 2 ft. diameter amalgamating barrel located in the gold room below.The barrel is of standard design and is rotated at 25 r.p.m. It is charged each day at 4 p.m., and grinding of the strake concentrate at approximately 70 per cent. solids is continued until 8 a.m. the following day. The barrel is then stopped, and the contents generously diluted with water, and after a few minutes rotation some of the slime is carefully poured off through the small discharge hole. This dilution and decantation is repeated until a good deal of the valueless slime has been removed.A further quantity of strake concentrate is then charged to the barrel, which is allowed a further 16 hours grinding period. After again diluting and decanting, approximately 25 lb. of mercury and 15 lb. of lime are added to the charge, which is then given an amalgamation period of 2 hours before cleaning up.By the process of grinding, diluting and removal of slime by decanting...

Jan 1, 1941

By Wylie A. W, Mathew P. J, Eisler P. L

Field studies of the radiations backscattered by iron ores from a 60Co source of primary gamma radiation located in a borehole logging probe have confirmed thatthe P" factor, a ratio of high energy gamma ray intensities to low energy intensities in selected energy windows of the backscattered gamma-ray spectrum, is a valuable measure of grade for sedimentary iron ores of the Pilbararegion of Western Australia.Laboratory studies of model boreholes have shown that variations in borehole diameter and variations in bulk density of the formations have a significant influence on the measurement of P" ratios. If these influences 'are taken into account the mean ore grade in a new blast hole, for instance, can be predicted with a probe of suitable configuration to within 0·8 per cent Fe at the 95 per cent confidence level, while the grade of a single 120-cm split can be determined to within 2·6 per cent Fe. These results were obtained by pooling data from five blast holes covering the range of iron concentrations 20-68 per cent Fe and apply to the mean hole grades 54-68 per cent Fe.Results for two development holes were generally comparable to those obtained from individual blast holes95 per cent confidence limits of ±0·9 per cent Fe for mean ore grade and ± 4·1 per cent Fe for single splits. A greater number of data points is needed before these confidence limits can be further improved.The technique utilized to obtain these results was derived from a "multiband" approach to collection of backscattered spectral intensity data, an approach which permitted selection at the data processing stage of the most statistically significant P" ratios for the type of mineralization encountered in the field. The multiband technique also permitted selection of the most significant of another set of windows in the backscattered gammarayspectrum to measure a newly developed "S-factor", a ratio sensitive to borehole diameter. Another window provided information on bulk density. All these measurements were made with a single pass of the same loggingprobe.

Jan 1, 1977

The celebrations which took place in 1986 to mark South Australia's Jubilee 150 served to focus attention on all aspects of the State's heritage. Until that time the sites and relics of South Aus- tralia's early mines had been generally neglected. Marked by the ruins of enginehouses and littered with the remains of the massive technology of the Industrial Revolution, these sites have now been recognised as containing the threads of a fascinat- ing story. In the early days of settlement the economy of the Colony was based on land and farming. Droughts caused periods of economic depression which were alleviated by chance discoveries of gold, lead, silver, and copper ore. Some of the mines which were opened on the copper deposits were the largest in the world at that time and their names well-known throughout mining circles. Working by hand with primitive equipment, the early miners excavated vast networks of shafts and stopes often extending to great depths: at Moonta- Wallaroo Mines for example workings extended to 860 m below ground. Because of the presence of underground water, mining to these depths would not have been possible without the Cornish pumping engine. Operated by steam power these massive engines and their associated equipment were transported from Cornwall by clipper and delivered to the mines by bullock cart. At this time the engines were at the peak of their devel- opment and, although expensive to import and install, they were highly reliable: the engine oper- ating Hughes pump at Moonta worked continu- ously for sixty years without a major breakdown.

Jan 1, 1987

This paper considers the standard of ore reserve assessments required by lenders when presented to support requests for project based loans. The way lenders use this information to structure a suitable financial package shows why ore reserves should be measured by industry set standards. This in turn raises questions concerning the assumptions used to derive mineable reserves from geological reserves. Consideration of the variety of related problems highlights the need for assessments to be defined according to acceptable standards. These should also address the suitability of the methodology to the assumed configuration of the orebody; the degree of variance and relaibility of estimates of grade and tonnage presented; and the estimation of probability that ore will in practice fall within the defined limits. In an increasingly international marketplace it is appropriate to compare Australian industry requirements to those of similar overseas industries, in this case the United States. Lenders would like to see that individuals responsible for the preparation of ore reserve estimates are certified on the basis of their skill and expereince by an industry body such as The AusIMM. The paper discusses how each of the parameters indicated above may impact upon a lender's assessment of the viability of a project. A number of practical examples are presented where inaccuracies or inadequacies in ore reserve information have led to reduced project performance.

Jan 1, 1987

By A Murphy, I Samsonova, N Eastwood, D Whittle

Part XI of the United Nations Convention on the Law of the Sea (UNCLOS or the Convention) (United Nations (UN) Division for Ocean Affairs and the Law of the Sea, 1982) establishes a comprehensive regulatory framework for the conduct of deep seabed mining (DSM) activities of mineral resources in the Area (defined in Article 1(1) of UNCLOS as ‘the seabed and ocean floor and subsoil thereof, beyond the limits of national jurisdiction’). Under that framework, DSM activities can only take place in the Area pursuant to an approved Plan of Work in the form of a contract with the International Seabed Authority (ISA) (the Authority), a 168-member international body created under UNCLOS to administer the Area. Private contractors can undertake DSM activities if they are sponsored by Member States of UNCLOS, providing a dual system of international and domestic regulatory control and oversight for activities in the Area.

Sep 1, 2024