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By B Leisemann, M Watkinson

Coal augering is an ideal method for recovering coal from the highwalls of open cut coalmines. Coal augering is a simple process whereby additional flights are added to the auger cutting head and auger holes are drilled at 1.9 m diameter up to 200 metres deep. Traditional monitoring was located at the mouth of the hole and if methane was encountered above two per cent, inert gas was delivered into the mouth of the hole to deplete the oxygen content at the auger cutting head below 12 per cent. The auger operator was asked the question ‘how do you know that this is the case?’ Trials were undertaken to prove that the oxygen content at the cutting head did drop below 12 per cent (the lowest limit for methane to ignite, also known as the oxygen nose point). Initial trials showed that the oxygen content in the mouth of the hole did not drop below 12 per cent and modifications were made to hold the inert gases in the mouth of the hole so that the auger flights could take this inert gas into the hole. In-hole monitoring, after completion of mining and after extracting the auger flights, showed that the atmosphere quickly returned to fresh air. In-hole monitoring was also tried during the augering process and yielded valuable results. This paper will discuss the results of the monitoring, information on the gas results obtained and the methodologies used to optimise the oxygen content at the auger face.CITATION:Watkinson, M and Leisemann, B, 2017. Inertisation of coal augering holes, in Proceedings Australian Mine Vent Conference 2017, pp 293–298 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By A H. Clemens, P Lindsay

Acid producing potential static tests have been undertaken on sample lithologies from New Zealand coal mines, to rank the lithogies into acid producing waste rock and stable non-acid producing waste rock. Results indicated that the main acid producing waste rock in the Waikato coal region are the marine Whaingaroa siltstone and the Glen Massey formations and the main alkaline producing lithologies were the Tauranga group volcanic-derived sediments (A & D) and the Mesozoic basement. Coal ash analysis of 28 samples from 28 mines have also been analysed for reactive S percentage and their base potential has been quantified by the chemical index of alteration (CIA). The results provide mine management in the Waikato Coal region with a classification of problematic and stable waste rock types. XRF and CIA values determined from wash drill cuttings would provide a method of determining waste rock volumes and magnitude of palaeo-weathering underground.

Jan 1, 1999

In several of the States of Australia, mining on private property has been seriously hampered by the fact that large areas of land have been alienated from the Crown before the discovery of gold or other minerals. In Western Australia this difficultyhas only occurred to a small extent, and has largely been overcome by an act entituled "An Act to Permit Mining on Private Property, No. XXIX., 'October, 28th, 1898." Under this act, the holder of a miner's right can apply for a gold mining lease on private land; such applicant may treat privately with the owner of such land as to the amount of compensation to be paid for surface ,damage, or the case may be brought before the Warden who will assess the damages. Private land used as a garden, orchard, or vineyard is exempt from lease, unless the applicant has authority from the owner, or such lease is limited to a greater depth than 100 feet from the lowest part of the surface.No lease shall be granted of any mines under any private land in any municipality unless either the applicant has authority from the owner, or such lease is limited to a greater depth than two hundred feet from the lowest part of the surface.The same regulation applies to leases of private land on which any hospital, asylum, or public building is situated or under or within one hundred and fifty yards laterally of any...

Jan 1, 1901

By I M. Platten, Y Xie

Complex gold deposits are generally characterised by variable geometries, strong structural controls on grade distribution and a high-nugget effect. The use of diamond drilling and fire assays in this environment often results in an understatement of grade. Bulk samples are likely to be the closest estimators of true grade, and may be required to evaluate geological/grade risk during resource estimation/feasibility studies. Any bulk sampling program requires appropriate planning and implementation. The planning stage should attempt to delimit the extent and nature of mineralisation; characterise mineralogy and metallurgical properties of the ore; and define bulk sample size and how it will be sampled/processed. The approach to sample processing will be governed by the results of metallurgical testing and geological knowledge. Careful design of sampling protocols must be undertaken through material characterisation, understanding of gold particle sizing and the application of GyÆs Sampling Theory.

Jan 1, 2008

Over the past few years, there has been an emerging relationship between business and civil society, especially NGOs. This relationship has the potential to bring about significant change, identifying common ground between commercial and societal interests. The mining industry has been a leader in acknowledging the need for community consultation and engagement. This paper argues that partnerships can make a very significant contribution to the industry as it comes to terms with the dilemma of an open economic system pushing against a closed ecological system.The paper will pose a number of questions: where is the locus for debate about sustainability in the mining sector?; how well embedded within companies are the new competencies that Leon Davis first identified in 1995 for the mining sector?; how has education for mining engineers or exploration geologists changed to prepare people for what are very different expectations within the working environment?; how well is the industry doing in managing its own environmental impact and what is its responsibility to an agenda for sustainability which extends beyond its own operations?;and how can NGO partnerships contribute to more sustainable outcomes? The paper does not aim to answer these questions, but to explore them in the hope that the issues and possibilities raised will contribute to advancing progress towards sustainability within the industry.

Jan 1, 2002

Fines and unnecessarily small rock fragments are created by as many as four identifiable breakage mechanisms which operate close to the charged section or sections of the blasthole. The peak blasthole pressure (Pb) should not exceed that value at which the rock starts to fail in compression. Excessive Pb values can be prevented by carefully selecting:1. the composition, density and/or diameter of the charge, and2. the initiation/priming system.The percentage of fines increases with:1. increases in the charge diameter:blasthole diameter ratio, burden distance, blasthole diameter, effective sub-drilling and size of blast, and2. decreases in blasthole spacing, stemming height and the length:width ratio of the blast block.Decked charges tend to reduce the percentage of fines.Excessive fragmentation is more evident in buffer blasting and sinking cut shots than in blasts fired to a clean free face. Initiation sequences which give effective burdens considerably less than drilled burdens encourage the minimization of fines, as does an inter-row delay time which promotes good progressive relief of burden.The wastage of explosive energy in creating fines is most pronounced where fully-coupled, energetic charges are fired in weak and/or highly porous rocks. This is especially so where forward movement of the strata is impeded by buffer rock, excessive burden distances and/or inadequate inter-row delay times.

Jan 1, 1979

By Blaisdell J. L, MacPherson G

The present communication records the results of a research investigation conducted in the Porcupine Gold Mines in Timmins, Onto. Soon after silicosis became a compansable disease in Ontario under the Workmen's Compensation Act in 1926, the attention of mine operators and physicians was drawn sharply to the prevalence and importance of this condition in the mining industry. A number of examining centres were established in Northern Ontario by the Workmen's Compensation Board, and the yearly X-ray examination of miners was made compulsory.Although working conditions were soon improved, the mining industry realized that they were confronted by a problem demanding basic research for its final solution. The late Sir Frederick Banting had, for a number of years, been interested in silicosis, and it was upon his suggestion that an experimental investigation was undertaken at the McIntyre-Porcupine Mines Ltd., Schumacher, Ont., in November, 1932. A preliminary report of this investigation was published in 1937 by Denny, Robson and Irwin and a further report by the same authors in 1939.Accepting the theory that silica exerts its injurious effect upon animal tissue through a slow transformation into silicic acid in the presence of body fluids; these authors assumed that if the solubility of the silicious material retained in the lung could be sufficiently reduced, the usual fibrotic response would be modified or would not occur. A search was therefore undertaken for some non-toxic compound that would fulfil this purpose. After investigating ma:qy substances, Denny and Robson discovered in 1936 that the presence of small amounts of aluminum powder almost completely inhibited the solubility of silicious material in vitro. An intensive study of the mechanism involved later showed that the reduction in solubility was due chiefly to a coating of the silica particle with a thin film of a gelatinous hydrated alumina which on drying formed the crystalline alpha aluminum monohydrate boehmite (AI203.H20). The presence of this absorbed layer on the surface of the quartz was indicated by -staining it with aurin (ammonium salt of aurin tricarboxylic acid) and proved by Germer and Storks by means of electron diffraction patterns.Inhalation experiments with animals were at once begun, using pure quartz dust with and without aluminum powder. (See original communications.) These observers showed that while typical silicosis was produced in about 5 months in the control animals receiving silica dust alone, the...

Jan 1, 1945

To form a true picture of the early history of Queensland, we must think of white settlement advancing like an incoming tide, wave by wave; each wave lapping ahead a little further than the last. The credit for opening up the country belongs to a large number of pioneers, each of whom pushed out just a little further than his predecessors.Contrary to what one might expect, Rockhampton district was settled by overlanders from the south and not from the ocean side. When the Archers, the pioneers of the Rockhampton district, reached Gracemere in 1853, settlement had already made its way down the valley of the Dawson River; for it was from Leith Hay's station at Rannes (a few miles below Mount Morgan) that the Archers advanced northward into the unknown, to find the river that the explorer, Ludwig Leichhardt, had told them must enter the sea somewhere near the Tropic of Capricorn.The Archers travelled northward from Rannes up the valley of the Dee, coming out on the edge of the Razorback Range not very far from the point at which the Dawson Valley Highway drops over into Poison Creek. (Their diary records the bearings from a lookout point to various peaks around Rockhampton, and to-day, by plotting back from these peaks, we can determine the exact spot at which they descended on to the Fitzroy Flats.) We can be certain, then, that they must have been the first white men to set eyes on Mount Morgan; though to them it would have seemed to be nothing more than an insignificant hill...

Jan 1, 1939

Standard petrographic profiles for many Permian seams from New South Wales and Queensland have been drawn up. The standard profiles of seams of the same age and from one or more coalfields were used to compile an idealized or type seam sequence for those coals in which more than half the seam profiles were similar to one another. A marked similarity existed between at least 7 of the 10 type seam sequences formed.The configurations of the vitrite-plus-clarite contents of the plies of 95 per cent of the seams could be formed from different arrangements of 3 basic sequences. These were...

Jan 1, 1970

By E Westthorp

Final mine sealing of BMA’s Crinum North mine, near Emerald, Queensland was undertaken in December 2015. Due to the benign atmospheric environment at Crinum North, the Queensland Mines Rescue Service (QMRS) Górniczy Agregat Gasniczy (GAG) unit was utilised to reduce oxygen levels throughout the underground atmosphere as part of the final sealing process.The GAG was utilised by way of a vertical borehole from the surface to seam to successfully reduce oxygen levels throughout the underground mine workings. Application of the GAG unit enabled the underground mine to be classified as stable and inert within days of the GAG operation, and subsequently cease gas monitoring at Crinum North. The data and information obtained from this activity provides valuable information to the underground coal mining industry on successful application of the GAG in realistic situations.This paper discusses the strategy used for sealing, the assisted inertisation and the results obtained from the application of the GAG unit. It discusses both the overall results and gives a detailed review of the gas monitoring data obtained via the tube bundle and real-time system, both during and following the use of the GAG unit.Gas monitoring results obtained and the strategy used are critical to share with the industry to obtain a better understanding of how the GAG unit works, and how it can be applied for emergency preparedness, emergency response or planned inertisation.CITATION:Westthorp, E, 2017. A review of the strategy and gas monitoring results obtained during the use of Queensland Mines Rescue Service GAG unit at Crinum North mine, in Proceedings Australian Mine Vent Conference 2017, pp 309–318 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

ALTHOUGH great progress has been made in flotation of the Broken Hill silver-lead-zinc ores, no paper dealing with this subject has been presented to the members of the Institute since James Hebbard's valuable contribution in 1913. Almost every discovery or development in the history of flotation has formed the basis 6f a patent, and but few experimentalists have overlooked the fact that their investigations might lead to the establishment of a patentable process. This, together with the aftermath of patent litigation, naturally resulted in secrecy being maintained in matters appertaining to the art, and the industry as a whole has consequently suffered considerably. Much valuable time has been wasted through numbers ofmen repeating work along certain lines, which, unknown to them, had already been thoroughly exhausted by others, whereas a lot of this would have been avoided by a freer interchange of information amongst those directly concerned. Owing to differences in the ore treated and the various applications of flotation concentration in relation to gravity methods, the flotation problems of the various mines differ considerably. This, together with the secrecy previously referred to, hasresulted in the development of numerous systems and machines, most of which would appear, to the casual observer, to comprise separate and distinct processes. The author has endeavoured to show how much these processes have in common with one another, and, at the same time, has tried to convey some general ideas on flotation to those members of the Institute who are not directly associated with this branch of concentration.

Jan 1, 1919

THE township of Costerfield is situated in the parish of Costerfield, county of Dalhousie, and lies 6 miles east of Heathcote and 30 miles south-east of Bendigo. It is separated from Heathcote by the Mt. Ida Range, which forms the western boundary of the Silurian formation. It is situated at the head-waters of Tin-pot Creek, a small southerly tributary of the Deegay Ponds Creek, which flows east to the Goulburn River.The field was discovered in 1860 by two prospectors, Coster and Field, who were guided there by a shepherd, M Nicol Coster and Field had already discovered an antimony lode about three miles nearer Heathcote, when M Nicol offered to guide them to the larger outcrop. The main Costerfield reef at that time projected above the surface, and was white through oxidation, though the bluey sulphide showed on fracture. No alluvial gold of any consequence was obtained at Costerfield, but a little was obtained, at Redcastle, 7 miles to the north, and in some of the gullies to the east.Following its discovery there came a period of prosperity to Costerfield, while the mining operations were confined to the oxidized zone. The early success of mining at Costerfield was due to the gold values, and it is probable that the oxidized zone was secondarily enriched. The earliest available record of values is a crushing of Coster and Co. on the Antimony reef (now known as the Costerfield reef), when 200 tons from a depth of 70 ft. averaged 4 oz. per ton in July, 1861. At this time a crushing mill had not yet been erected at Costerfield, and the ore was carted and treated at Redcastle. The massive antimony ore, consisting of mixed oxides and sulphides, was separated by hand-picking as "marketable ore," and the remainder crushed for gold. A higher average is recorded from South Costerfield in September, 1861, when a 15' cwt. parcel...

Jan 1, 1922

By A Liu, T Ren

Gas explosion in underground coal workings can pose a serious threat to the safety of mine workers and the entire mine operations. Gas explosion is a very complex thermal-chain reaction in a confined underground environment. Based on combustion and explosion theory, three dimensional (3D) computational models were developed to simulate mine gas explosion flame and overpressure wave propagation in a single entry gateroad in underground coalmines. Six different explosion scenarios were modelled and compared with large scale experimental results and AutoReaGas simulations. Model validations show that the use of shear-stress transport (SST) k-? model together with eddy-dissipation model (EDM) produces good agreement with both experimental and AutoReagas simulation results. Modelling results demonstrated that the changes of temperature versus time can be divided into four stages, ie the initial condition stage, and periods of warm-up, active burning, and burnt-out. Assuming a limited volume of methane is involved in the explosion, the maximum temperature decreases as the distance increases from the explosion point, with the highest temperature reaching about 2460 K. Modelling results show that the evolution of the explosion flame shape experiences four typical stages, ie spherical flame, finger-shape flame, flame with the skirt touching the side walls (ribs) and tulip flame, which are similar to the pattern of a duct explosion. The pressure in the gateroad remains the same as the initial value before the arrival of the explosion wave and then increases rapidly to the maximum value. Modelling results from this study will be used for the design of explosion arresting devices and mine seals in underground coalmines.CITATION:Liu, A and Ren, T, 2017. Computational simulation of gas explosion and its propagation in single entry gateroad, in Proceedings Australian Mine Vent Conference 2017, pp 181–188 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

Solid Energy New Zealand Limited has grown significantly since becoming a State Owned Enterprise in 1987. Exports, profit, turnover, output per employee are all trending upwards. The company has identified the management of Health and Safety as a key capability to sustain future growth, and to add value to the business. It has set a target of being the best practice in managing Health and Safety.   This paper examines the company's activities in the Health and Safety area, and how it sees that value can be added by preventing and containing losses through accidents involving people, property, process and the environment. Solid Energy is confident that a Planned approach to managing Health and Safety can achieve this. It will explore historical events, strategic changes, Health and Safety systems, Benchmarking, Performance Measures, initiatives, progress to date and challenges for the future.

Jan 1, 1997

Situated in the Greymouth Coalfield, the Mt Davy Block contains a significant resource of high quality bituminous coal suitable for use in metallurgical coking coal blends. The coal, which is all low sulphur, is seen as a complementary deposit to export coking coal at Stockton Mine.   Previous drilling by State Coal Mines (1948 - 1953) and Japanese interests (1970's) have been supplemented by Coal New Zealand drilling (1992 - 1993) and surface mapping. A mining feasibility study was completed in late 1993 and approval gained for the driveage of an exploratory tunnel to the target seam.   Following construction of surface facilities, tunnel driveage on a 1:5 decline commenced from Rewanui in May 1995 and to date about half the required length has been driven. When the seam is intersected a comprehensive geotechnical testing programme will be undertaken to assess the in-situ mining conditions. It is expected that the results will confirm the assumptions made in the feasibility study.   The Mt Davy Mine, at depths of 500 - 700 metres, will be the deepest underground coal mine ever inNew Zealand and in-situ stresses (orientation and magnitude) will be important considerations for mining engineering. The coal has a high gas content and suitable techniques for gas control and prevention/mitigation of coal outbursts will be necessary.   Mine development is scheduled to commence in mid 1998 and an annual production level of 500 000 tonnes is forecast. The coal seams will be developed by continuous miner and coal extraction will be by hydraulic monitor. Coal will be pumped to the surface and from Rewanui transported five kilometres to Dunollie either by truck or slurry pipeline. At Dunollie a coal dewatering plant, coal stockpile and rail loadout will be constructed.

Jan 1, 1996

By E Apaza, R Neumayr

This paper aims to summarise the discovery of the QTS Central resource, a previously unidentified +1 Mt inferred resource that lies between two major CSA resource systems.The 1.7 Mt at 5.76 per cent Cu, QTS Central ore system represents 1/6th of the CSA mineral resource and was discovered in 2014 based on the accumulation of historic exploration records dating back to 1989.The CSA deposit consists of five ore systems hosted within turbidite-derived siltstones (CSA Siltstone) and lesser sandstones (five per cent) of the Devonian Amphitheatre Group. The host sediments strike approximately north–south with a steep westerly dip and exhibit a well-developed east dipping cleavage. Most CSA mineralisation is hosted within dilation zones at the intersection of cross-cutting structures and is interpreted as epigenetic in origin.Alteration and weak mineralisation, up plunge to the reported QTS Central mineral resource, was initially detected in 1990 during a downhole electromagnetic conductivity (EM) study, where one hole indicated an off-hole conductor, later tested with four diamond holes. One of these diamond holes intersected 3 m at 7.5 per cent Cu at 200 m. Development of the 9070 Subway drive in 2005/2006, linked the QTS North and QTS South workings and intersected structures interpreted to host QTS Central mineralisation. Subsequent drilling proximal to the 9070 Subway in 2007 identified an up plunge extension to the QTS Central zone (UDD07152: 1.8 m at 6.3 per cent Cu from 10.7 m). Work on QTS Central was largely forgotten until 2012 when the mining of a 450 m infrastructure drive provided a platform to test the anomalous grades. In December 2013, drill hole UDD13055A intersected 20.9 m at 7.2 per cent Cu from 378 m. By the end of 2014, the QTS Central inferred resource was 1.0 Mt at 6 per cent Cu and 18 g/t Ag (Hosken and Apaza, 2014). Late in 2016, further infill drilling occurred from two fronts to increase confidence in the QTS Central resource. The results of this drilling are expected late in 2017.The current interpretation indicates the QTS Central system consists of two main lenses hosted within closely bedded sandstones and siltstones. The sandstone in general is not mineralised, being heavily silicified, while the siltstone is mineralised and chloritised. The main mineralised lens is 75–200 m along strike and 450 m high. Massive sulfide feeder structures lie at the core of the two main lenses, although the characteristics of the QTS Central system tend toward the mineralisation being more chlorite-rich than in QTS North and QTS South.CITATION:Apaza, E and Neumayr, R, 2017. The discovery of the QTS Central ore system, CSA mine, Cobar, NSW, Australia, in Proceedings Tenth International Mining Geology Conference 2017, pp 151–156 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

The paper is a general review of practice in design of sub-level open stopes in Northern Rhodesian copper mines and gives examples of some interesting developments during the last five or six years. It discusses the effect of hangingwall subsidence and the methods used to combat rock pressure on working areas.INTRODUCTIONAll producing mines on the Northern Rhodesian Copperbelt have large ore reserves and are designed for high rates of production. The three mines (Mufulira, Rhokana Corporation, and Roan Antelope) where sub-level open stoping is used, hoist from 250,000 to over 400,000 short tons of ore a month so that any stoping method used must be adaptable to concentrated' mining. Individqal stopes produce from 5,000 to over 25,000 short tons of ore a month.Structure af the ore bearing sediments is simple; faulting in ore is almost entirely absent and copper mineralisation is found in the same beds over great distances...

Jan 1, 1954

By K A. Bunker, A D. Campbell, E Ah Mu, A R. Penney

The Ernest Henry mine is a transverse sublevel cave (SLC), which is relatively unique due to the 45 degree inclination of the orebody. To economically recover ore, each sublevel is horizontally offset from the previous level by around 25 m, depending on the orebody geometry. Mine development, slotting and initial production within this zone occurs in a high stress abutment that increases in magnitude at depth. These areas are seismically active and close to the hanging wall where cave propagation is yet to initiate. High stress conditions and the close proximity to the cave seismogenic zone results in challenging geotechnical conditions in the step out zone of each level and requires management of hazards including stress driven rockfalls, rock bursts and pillar failure.This paper outlines how these hazards were forecast using numerical modelling and geotechnical monitoring. Risk management techniques included dynamic ground support design, development of a new mine layout and extraction sequence as well as delayed re-entry into seismically active areas. Ongoing monitoring, instrumentation measurements and field observations were used to track the effectiveness of the controls.Future production levels are forecast to experience increasing stress and seismicity, which will increase demand on excavations and installed ground support. Ensuring the techniques and controls for monitoring, measuring and mitigating stress and seismic hazards are enforced is essential for continued safe production.CITATION:Campbell, A D, Bunker, K A, Ah Mu, E and Penney, A R, 2016. Managing stress and seismicity in an inclined sublevel cave, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 319–328 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By Jarc H

The steeply dipping silver/lead/zinc orebodies at Mount Isa mine have been extracted most recently by a combination of cut-and-fill and open stoping methods. Bench stoping was first used at Mount Isa Mine seven years ago to allow safe extraction of a highly stressed cut-and-fill stope. Subsequent benches have shown that the method offers significant cost and safety benefits through increased productivity and reduction in man exposure. The success of benching has lead to cut-and-fill mining being replaced at Mount Isa.Significant resources have been focussed to optimise benching. This paper describes the operational, planning, and research and development aspects which have contributed to the method to date. A brief look is also taken at the future direction of benching at Mount Isa.

Jan 1, 1992

Listing on Australian Stock Exchange Limited ('ASX') is a means by which a company can prosper and grow by gaining access to a large capital market. This currently stands at over $300 billion for domestic securities listed on ASX. A company seeking listing will benefit from a higher profile and a greater spread of shareholders. These result from, among other things, improved communications with the investment community. ASX recognises that a decision to list is an important step for a company. Owing to the diverse nature and size of the companies that consider listing and the various steps involved, it is recommended that guidance of professional advisers is sought as early as possible in the listing process. A company seeking listing on ASX must meet the prerequisites for admission to the Official List which, along with the continuing obligations that must be complied with following admission, are contained in the Listing Rules of ASX. Listing on ASX requires a company to ensure that, among other things, the market is fully informed at all times so that investors can make informed investment decisions.

Jan 1, 1996