Search Documents

On-line radioisotope gauges determine information on the characteristics of ore to enable improved control of processing operations. In the metalliferous mineral industry, in-stream analysis systems based on radioisotope X-ray techniques determine concentrations of valuable minerals at various stages of the concentration process. In the coal industry, on-line gauges determine ash and moisture contents, and the specific energy of coal.In-stream analysis systems developed in Australia are installed in about 30 mineral concentrators. Their use has led to the increased recovery of valuable minerals, and the time taken to recover the cost of installation is usually several months. The savings to Australia resulting from use of these analysis systems is estimated to be more than $A 15 million per year.Australian experience in the training of mineral industry personnel shows that the most effective approach is to combine courses on nuclear techniques and control of processing operations. This is the basis of Australia's contribution to the minerals sub-project of the United Nations Development Program (UNDP) Industrial Project.

Jan 1, 1985

By J P. Richards, M D. Johnston

The Porgera gold mine, located in the highlands of Papua New Guinea, produced 7.7 Moz of gold between 1990 and 1998. Reserves are estimated to be 12 Moz of Au. The deposit is associated with 6 Ma-old mafic alkalic intrusions emplaced at shallow levels into unconsolidated Jurassic and Cretaceous sediments, where they caused the formation of peperites. The mineralisation consists of an earlier base-metal-sulphide-rich stage with sericite-carbonate alteration (stage I), and a later phase represented by quartz-roscoelite veins (stage II). New styles of mineralisation and alteration have been recognised at depth in association with stage I. They consist of the assemblages magnetite-chalcopyrite-pyrrhotite and biotite-actinolite-anhydrite respectively. In addition, the recent recognition of adularia in some stage II veins (with roscoelite) confirms the similarity of this style of mineralisation with other adularia-sericite or low-sulphidation epithermal deposits.

Jan 1, 1999

A pilot plant has been constructed for the low temperature carboni-zation of Wallarah (N,S,W6) coal at the rate of 300 pounds per hour. The plant was built and tested at Australian Mineral Development Laboratories for Broken Hill Pty, Ltd. Char product was required within the specifi-cation 15.5 `S' 1 per cent volatile matter. The design was based c atz an entrained state carbonizer developed by Parry and U.S. Bureau of Mines co-workers at Denver, U.S.A. The method involved the carbonizatioan of fine coal by entrainment with air in an externally heated reactor.. The heat required for carbonization of tits coal was supplied to the be, both through the reactor walls and also by internal cambustion of products .

Jan 1, 1963

By Nidagal V

This paper discusses the dewatering strategy adopted and the considerations and procedures required to incorporate a dewaterinq scheme into the Mt Whaleback mining operation. It concludes that in pit pre-dewaterinq has successfully allowed mining to progress below the standing water level with the minimum of disruption or radical change to the mining method. It is recognised however, that dewatering is not a static activity and there is a requirement for ongoing investigations and development. Pre-dewatering commenced in October, 1984. Purpose designed pumping trailers have been employed to minimise the loss of pump availability resulting from the frequent. need to remove and reinstall pumps when close vicinity blasts occur. To July, 1986, some 0.5 Mm' of groundwater had been pumped from the unconfined orebody aquifer. Mining has progressed to some 20 m below the standing water level without. any undue water associated problems. Ultimately, it is ,cheduled to extend some 300 in below the original water level in the West Pit. With the development of an increasing area of the mine below the standing water level, the influence of seasonal high intensity rainfall events, which had previously caused little concern, now need to be addressed. Pumping equipment has been designed to evacuate storm water at a rate consistent with mine production Considerations.

Jan 1, 1986

This paper will first discuss the fundamental requirements for reliable discharge of backfill by gravity alone at high per cent solids. This discussion will include brief mention of the underlying principles of saturated solids flow contrasted to that of stirred tank or dilute discharge systems. Here the need to possess full knowledge of the flow properties of the stored material will be highlighted. In addition proper account must be made of the silo overflow weir and settling capacity to match plant throughput. Here opportunity will be taken to highlight the complexity of this multi-phase flow situation as well as the general yet paramount requirements for reliable solids flow. It will be shown that by proper attention to the multi-phase considerations gravity discharge of slurries as a consolidated bed with minimal water content is possible. Such high solids discharge results in greatly reduced demand for process water. In addition pumping costs are reduced as is the delay time associated with the mine drainage operation. Confirmation of successful applications will be highlighted by reference to several recent case studies. In the concluding phase mention will be made of the key yet very simple and effective operation techniques which enhance reliable discharge. The simplicity and reliability of properly designed gravity discharge backfill tank systems suggests increased application of this technology by the mining industry.

Jan 1, 1998

By Nag D. K

King Island Scheelite is a wholely owned subsidiary of Peko-Wallsend Ltd. The company works two underground mines near the southern end of King Island at the western approach to lass Strait, 240 km south of Melbourne. (See ^igure 1).

Jan 1, 1981

An empirical method of estimating dense rock (D.R.E.) equivalent volumes erupted as airfall tephra, described in a companion paper in this volume, is elaborated, and its accuracy discussed. Estimates obtained from a single eruption can be classified as to whether they show positive, negative, or constant relative dispersion. For positively dispersed tephras (estimated volumes increasing with distance), this procedure improves the accuracy of the method. The technique is applied to selected andesitic tephras erupted from Egmont Volcano, New Zealand, during the last 28 000 years, which are found to range in volume from about 1.5 x 107 m3 up to about 2.4 x 108 m3 D.R.E. With a factor of about 16 between the smallest and largest volumes, this contrasts sharply with the rhyolite volcanoes in New Zealand, where the difference factor is usually of the order of 100. The largest tephra eruptions at Egmont are small compared to the largest debris avalanches, which have exceeded 1010 m3 (10 km3) in volume.The magnitude versus frequency relationship, calculated using a maximum likelihood method, establishes the limits of eruption magnitude at Mt Egmont as 107 to 109 m3 D.R.E. For some volcanoes, the magnitude-frequency relationship changes with time, owing to clustering of eruptions, separated by long dormant intervals. Ngauruhoe Volcano, New Zealand, is an example. Within eruptive episodes, the mean interval between eruptions of >_ 105 m3 is about 0.9 ¦ 0.65 years. The mean interval between eruptive episodes in which >_ 106 m3 is erupted, including episodes in which this volume is erupted gradually, is about 25.8 ¦ 6.6 years, and the mean dormant interval between all episodes is about 5.2 ¦ 3.0 years. At present Ngauruhoe is in an unusually prolonged dormant period, 50% longer than any in the historical record, since 1839.

Jan 1, 1990

By Hamblyn S

Oakbridge, in combination with its joint venture partner, Nippon Steel of Japan, is expanding its Bulga underground and open cut mines to meet the growing demand for coal in the Asian market. Expansion works underway will see the Bulga underground mine become a world leader in underground productivity, the introduction of a high capacity dragline into the open cut mine (largest capacity dragline in NSW) as well as a major upgrade of the coal preparation plant (CPP) and coal handling facilities (CHF) to process the increased production. This paper describes the planning and implementation of this major expansion program and highlights the rationale behind some key aspects of the program.

Jan 1, 1995

By T Dawson, B Haskins

Fatigue is it the newest buzz word or is fatigue a real phenomenon that is creating safety and organisational risk for you? There is no debate that fatigue is natural, and it affects us all, just like gravity; however, there has been much debate on the severity of its impact in the workplace. For many years the impact was not measurable, hidden out of sight and, quite frankly, written off as the infamous ‘operator error’. Over the last several years, advancements in technology have provided safety and health professionals, sleep scientists, fatigue experts and organisations with the ability to monitor and detect fatigue events in real time, as well as predict and monitor increased risk for fatigue events. Caterpillar Safety Services has assembled an extensive and exceptional set of technologies that will provide the best methods and data to measure the impact of fatigue. This paper will discuss fatigue in the workplace and review the technologies and data sets available, which will allow the reader to determine whether this risk is real or rubbish.CITATION:Haskins, B and Dawson, T, 2017. Fatigue risk in your operations – real or rubbish? It actually depends , in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 137–142 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

Comparatively recent Tasmanian legisla tion established a series of rigid control standards for environmental protection just as ma spectacular expansion of the mining industry was nearing completion. Upgrading existing protection to obtain the necessary licence to operate under these new regulations required further major works and involved a considerable outlay of non- productive capital at a time when escalating costs and falling metal prices were straining economic efficiencies to the limit. Late in 1974 a major environmental protection scheme was commissioned by the Electrolytic Zinc Company of Australasia Limited at Rosebery on the West Coast of Tasmania. This 4 million dollar project was specifically developed by the Company ahead of and to meet the new standards for control of total effluents discharged from its zinc-lead -copper-pyrites mine and concentrator.

Jan 1, 1977

By R Winterberg

Concrete is a well established and reliable construction material for the permanent lining of tunnels, but shows some weak performance characteristics, which can be overcome by the addition of specialised fibre reinforcement. This paper addresses the particular performance design requirements of segmental linings, discussing the improvements of fi bres on concrete properties. Focus is made on the beneficial effects of fibre reinforcement on the cracking behaviour and the toughness performance, providing a safe and durable tunnel lining.Not only the mechanical performance of fibre reinforced concrete (FRC) for segmental linings, but also the durability of the linings has gained growing attention among the designers and consultants. Especially tunnel linings with exposure to media with corrosion potential, such as wastewater sewer tunnels or desalination plant outfall tunnels, have high requirements on their durability. The design of these structures must provide a comprehensive study of durability aspects. Fibre reinforcement can substantially improve the durability of concrete.Research has been carried out on the cracking behaviour of concrete. The beneficial effects of steel fibres on the cracking behaviour reduce the permeability by reducing the flow paths within the concrete. Crack bridging steel fibres create necking effects in bending cracks, leading to earlier closure of the cracks. Further, steel fibres create particular crack formations, which lead to a substantial reduction of the fl ow rates through separation cracks. The results also show that considerable cost savings can be achieved using FRC, as the thickness of the linings can be reduced.The durability design issues will be addressed and underlined by a case history on the Hobson Bay sewer tunnel in Auckland, New Zealand.

Mar 8, 2011

Most types of nuclear power reactors use uranium dioxide fuel. Power reactors using natural uranium dioxide'fuel are of special interest to countries such as Australia that have their own uranium supplies. A wide range of uranium dioxide powders can be fabricated and the ideal one flows readily, presses without the need for binders or lubricants, sinters to the required density and gives low reject rates at all fabrication stages. Sinterable uranium dioxide is usually produced via the ammonium diuranate route. The A.A.E.C. is aiming to demonstrate production of nuclear grade uranium dioxide from Australian concentrates, improving technology where possible. Details are given of the dissolution, solvent extraction, precipitation, filtration, drying, and calcination-reduction steps. Solvent extraction from sulphate media is also under study with a view to developing a process to produce a nuclear grade product at the mine treatment plant site,

Jan 1, 1969

By Dinuzzo P, Wychie J, Desoe C

The Selwyn Gold-Copper Mine is located 150 km southeast of Mount Isa within Proterozoic units of the Mount Isa inlier (Figure 1). Mineralization in the mine area is associated with strongly sheared ironstones and iron rich schists at the base of the mid- Proterozoic Staveley Formation. The ironstone horizons outcrop as a series of dominant ridges over a 10 km strike. Economic gold-copper mineralization has been defined in 4 separate zones within a 3.5 km length of the outcropping ridges. A current combined geological resource for the deposits is 5.3 million tonnes of 5.0 g/t Au and 2.02 Cu. Weathering of the deposits has resulted in a pronounced vertical zonation of mineralogy, especially copper, within the ore zones. This has produced 3 separate ore types which require different treatment techniques. The categorization is based on copper content and zones are termed leached (surface), oxide and sulfide. Ore removed from the pits will be mainly leached and oxidized with minor sulfide near the pits final depths, while the underground ore will be from the sulfide zone with minor oxide in some areas.

Jan 1, 1989

By A F. Cropp, D J. Bradshaw, W R. Goodall

Mineralogy and critically the texture of both the ore and gangue phases are of paramount importance in the flotation recovery of copper from porphyry ores. Mineralogy and texture will define the theoretical grade recovery curve for a feed ore. Actual grade-recovery falling below this may be due to texture and gangue influences, whilst desired grade-recovery above this line will not be possible unless the characteristics of the feed are altered.This review discusses examples of porphyry copper deposits where process mineralogy has been used to characterise these textural and gangue influences on recovery by flotation. More specifically, the influence exerted by grain size, liberation, association and elemental distribution is explored. The implications of these on overall plant philosophy and operation are highlighted, along with the subsequent potential impact on recovery.CITATION:Cropp, A F, Goodall, W R and Bradshaw, D J, 2013. The influence of textural variation and gangue mineralogy on recovery of copper by flotation from porphyry ore - a review, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 279-292 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

The diverse nature of inadvertent mine fires does not lend them to general treatment. But evolving from the unfortunate fires over past years is a simple principle in dealing with all fires to bring combustion under control. Control, in brief, means that the products of combustion, themselves possibly still with fuel values, are not revitalised by addition of fresh air. There are problems with fire- fighting, especially with water, as this may lead to production of CO and H2. Panel ventilation upstream of the fire must be controlled to direct all air over the fire. Some advantages in fire fighting are found by the use of "sails". Early diagnosis of fires and early treatment are essential for safety of personnel and safeguarding and recovery of property. Preparedness extends to up to date documentation, but first hand knowledge also is invaluable to the diverse personnel gathered to fight a fire, and in the decision making Involved.

Jan 1, 1981

Conventional narrow vein mining, utilising hand held methods, is expensive and requires specialised miners who are becoming a rarity. Hand held mining techniques (shrinkage stoping, leading stoping and cut and fill) have the advantage that they can be selective. The methods allow continued sampling of the face, control of hanging wall conditions and are adaptable to changes in strike and dip. On the other hand, more productive longhole stoping methods can allow excessive dilution due to drill hole deviations and changes in orebody dip and can be subject to unexpected hanging wall or footwall failures. Development of small scale equipment (as narrow as 0.8m wide) used for drilling or bogging very smallaccess drives has been ongoing over the past decade. In this paper, types of equipment are examined and compared, particularly with respect to their produc- tivity, size, and working environment. The introduction of electric hydraulic equipment has provided a better working environment with reduced noise, exhaust fumes and heat. The concept of the "hydraulic cherry picker" may have application in mining steeply dipping orebodies. The system requires orebodies to be reasonably consistent in dip over 15 metre sub-level intervals. The system involves the basic concept and skills of machine and airleg mining, combined with the safety and productivity of a mechanized work platform. The platform or basket is stabilized between the hanging wall and foot- wall by hydraulic rams and is extended by a tilting hydraulic boom mounted to a small prime mover or trailer. Design concepts (including remote controlled charging of explosives, adaptation to the boom for rock cutting and the overall electric hydraulic mining concept) are put forward in the paper as a view as to how narrow vein mines will be mined in the future.

Jan 1, 1987

The paper covers the history and develop- ment of electrical and diesel-powered hydrau- lic percussion rock drills. It examines main design aspects and problems encountered in pro- ducing an efficient and reliable machine to fully cover the nominal hole sizes required for underground development, production drill- ing and for general quarry work. The main design features and advantages of a hydraulic rock drill are relatively low input power requirement to energy per blow (this being achieved by the use of an electric or diesel- powered hydraulic system) and a specially con- structed piston using a powered damper cylinder to absorb the recoil forces from the drill steel and reduce stresses on the drill, feed and hydraulic boom. A further important design feature is the anti-jamming device which controls the drill both during manual and automatic operation. This anti-jam device works on feed and rotation press and prevents the drill bit becoming jammed in broken or soft ground. These features and many other mechanical and environmental benefits are highlighted when comparing hydraulic percussion rock drills with current pneumatic machines. The hydraulic rock drill gives an overall high penetration and production rate, with an added bonus for ergonomy and environmental conditions such as lower noise level, no fogging from air and oil exhaust (which naturally gives better air for breathing),plus improved vision when in under- ground situations. Hydraulic rock drills and systems have been fully tested in many mines, quarries and contract sites during the past years. They h6! been improved and modified and are now provi~ to be very reliable and economical piece drilling equipment whò in mines and quarries.

Jan 1, 1978

By C MacRae, N Wilson

CSIRO Minerals has recently developed an electron microprobe (EMP) based imaging (or mapping) method for characterising ilmenite concentrates. The method requires an electron microprobe analyser to collect elemental X-ray maps which are then processed via an in-house developed software module (CHIMAGE). The type of information readily available from EMP mapping includes; primary phase identification, modal analysis of phases, chemical analysis of individual phases, textural information (eg the alteration stages in the formation of leucoxene or pseudorutile from primary ilmenite and the development of macro-porosity), and the identification of coatings or pore-fill material. All of these parameters will impact on the choice of future downstream processing options considered for any particular ilmenite concentrate. The method has been demonstrated to be a sensitive analytical tool for assessing the distribution of aluminosilicate minor impurities in ilmenite feedstocks from the West Coast of Australia and also for characterising the complex chrome-spinel gangue phases common in East Coast ilmenite concentrates from the Murray Basin.

Jan 1, 2001

The purpose of this study was to investigate the effectiveness of froth fl otation for the recovery of gold from the gravity tailing stream of the former Lihir Gold Limited (LGL) operation in Ballarat. The P80 of the tailings was determined by screen analysis as 1 mm, with test work conducted on as received material along with samples ground to P80 sizes of 47, 78 and 134 microns. Laboratory scale batch flotation tests were conducted at both natural and elevated pH to investigate the impact of pyrite depression on gold recovery. Results indicated that although an increase in grade from approximately 0.7 g/t to 3 g/t was achievable at a natural pH and a P80 of 134 micron, gold recovery was low at just 35 per cent. Finer grind sizes were found to have an adverse effect on both grade and recovery. Future efforts will be focused on the sub 310 micron size fraction of the tailings, which was revealed to contain approximately 85 per cent of the available gold and may be amenable to cyanidation or ultra-fine gravity treatment.

Aug 1, 2010

By Xu C

This paper describes the structure and operation of an interacth.. computer program for mineral industry financial analysis and production planning. It includes comprehensive risk analysis with correlated variables and optimal production scheduling using Lane's balancing cut-off grades and the general dynamic programming approach.

Jan 1, 1995