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Alluvial gold exploration is aimed at recognizing areas of anomalous gold content as evidenced by the nature of the drainage system, its age, geomorphic history and other features of the geological environment including the provenances. Subsequent studies to quantify the findings are governed by the need for accurate data based upon precise measurements. Computerization allows the use of more complicated mathematical procedures than are feasible manually, thus promoting the development of more advanced technological aids. Data banks provide the means of storing vast quantities of information for instant recall.Sample representivity is a major problem and a clear understanding of both sampling and analytical requirements is essential for dealing with problems arising from variations in sample size and particle size distribution. Field samples must always be large enough to ensure adequate representivity or the sampling has failed in its purpose.

Jan 1, 1984

The Coal Corporation of New Zealand Ltd (CoalCorp) is the largest coal producer in New Zealand, with extensive properties in both the North and South Islands. CoalCorp's North Island operations are kilcmetres to the south of Auckland. opencasts, are located in the catchment wildlife, historical and scenic values. in this catchment is the single most mining operations. centred on Huntly, a town some 80 Five coal mines, four of which are of Lake Waahi, a lake with significant The discharges of mine lodgement water important environmental constraint on Throughout New Zealand the use of water is controlled by a statute called the Water and Soil Conservation Act 1967. All industrial water users are required to hold Water Rights, which are in effect licences to take, use, dam, divert or discharge water. Water Rights are obtained through a legally defined process and any potentially affected party has the per to object to their granting. A special tribunal hears the evidence for and against an application, and issues its decision, which is reviewable in a higher court on Appeal. Rights, if granted, are issued subject to conditions and, in the case of mining discharges, limits would be set on flaw rate, suspended solids concentrations, turbidity, pH and the concentrations of any potential toxicants. This paper presents a case study of an integrated, catchment wide water management plan for Lake Waahi, that was prepared by the author, and others while the author was in the employ of CoalCorp, and its predecessor, State Coal Mines. The author is grateful to CoalCorp for their permission to submit this paper.

Jan 1, 1988

By N Khalili, J Zhao, G F. Zhao

Toppling failure of a jointed rock slope was studied by using the distinct lattice spring model (DLSM). Compared with the classical discrete element model, the DLSM has the advantages of free calibration of micro-mechanical parameters and easy to represent discontinuities, and is more computationally efficient. In this work, the DLSM was used to investigate the toppling failure of jointed rock slopes. The numerical simulation was verified against experimental data from a centrifuge model test on a jointed rock slope. Both the horizontal deformations and failure pattern observed in the centrifuge test were reasonably reproduced using the DLSM. Then, the mechanism of the flexural toppling failure was studied numerically by using a parameter analysis. Finally, some insights were derived that may be useful for practical engineering.CITATION:Zhao, G F, Khalili, N and Zhao, J, 2014. Application of the distinct lattice spring model on toppling failure of a jointed rock slope, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 207–214 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By Bogie I, White P. J

Active geothermal systems occur widely in Sumatra and in the Taupo Volcanic Zone (TVZ) of New Zealand. There are also many occurrences of epithermal gold mineralisation in Sumatra, some of which are economic. Minor sub-economic occurrences of gold have been reported in the TVZ but none have yet been mined. There are both similarities and differences in the nature of the active geothermal systems and mineral deposits in Sumatra and New Zealand, which can be systematically related to the tectonic setting. The thicker crust and consequent predominance of silicic volcanism in New Zealand leads to hydrothermal. systems which are little eroded and with limited lateral outflows. The systems in Sumatra are of mixed character, with some of the characteristics of those in andesitic island arcs such as Java or the Philippines, eg a higher proportion of systems with identifiable acid magmatic volatiles, a greater potential for deep erosion and lateral outflows than in New Zealand; but modified by the more oblique component of subduction and thickened crust so that some are localised in volcano-tectonic depressions and consequently have high piezometric levels of primary hydrothermal fluid. The unusual occurrence of calcic zeolites in veins associated with gold mineralisation in Sumatra is thought to be indicative of "satellite" boiling zones along de-gassed hydrothermal outflows.

Jan 1, 1995

In the late 1970's Western Mining Corporation, Exploration Division considered the purchase of a major multi-element spectrometer as an adjunct to our existing atomic absorption spectrophotometers. The analytical work proposed for the unit included barium, uranium and rare earth elements from Olympic Dam, uranium, sulphur, vanadium and strontium on Yeelirrie type deposits, major element and whole rock analysis, multi-element analysis of samples from the laterite, chromium and manganese exploration programmes and tin and arsenic analysis. These were all analyses that were not readily or easily performed by flame atomic absorption or were where we expected that a simultaneous multi-element instrument would be an advantage. Also the turnaround times for the commercial laboratories was considered unacceptably long for some determinations. Other factors, important when considering the spectrometer were the ability to ensure confidentiality of results and the ability to assign our own priorities and not to have to rely on commercial laboratories. The two techniques considered were X-ray Fluorescence Spectrometry and Inductively Coupled Plasma Optical Emission Spectrometry. The decision was made in favour of the ICP unit for several reasons. The ICP fitted in with our existing methodology, ie samples digested for atomic absorption or colorimetric techniques would also be suitable for ICP analysis and vice versa. The technique was suitable for water samples and for major element analyses and for rare earth elements. X-ray fluorescence spectrometers were installed at the Kambalda and Belmont laboratories and would be available to us for routine checking and for elements not suitable for ICP analysis. The final consideration was price. ICP was considerably cheaper than XRF.

Jan 1, 1987

By Smith J. W, Hart G. N

Compositional and isotopic analyses of coal seam gases in the Southern Coalfields have shown that these gases frequently contain abnormally high concentrations of magmatically derived carbon dioxide. The size of this carbon dioxide reservoir and the extent of permeation of the sediments by carbon dioxide are not known.Therefore caution in evaluating the natural gas potential of the region is advised.

Jan 1, 1981

By Eggins SM, Crawford AJ, Maillet P

The Fiji Islands are remnants of a once continuous Solomon-Vanuatu-Fiji-Tonga volcanic arc (the Vitiaz arc), located at the boundary between the Indian-Australian and Pacific plates. They record a history of (i) arc volcanism the late Eocene to late Miocene, (ii) an extensive magmatic response to arc rifting (5.5-3.OMa) during which volcanism was dominated by shoshonitic to tholeiitic basalts, and as rifting continued, (iii) a transition from arc to intraplate volcanism. The Hunter Ridge-Hunter Fracture Zone separates the inactive South Fiji Basin from the actively spreading North Fiji Basin, and has been considered to be a transform zone, almost parallel to the motion vector of the Australian plate. However rocks dredged during the 1993 `Alize' cruise, from along the northern part of the Hunter Ridge are typical arc tholeiites, and therefore demand that subduction has occurred beneath the Hunter Ridge sometime during the last û 5Ma.

Jan 1, 1995

Grey River Gold Mining Ltd commenced dredging alluvial flats in the Grey River Valley in 1989.Previous drilling indicated over 100 million cubic metres of gravels with some 90% of the gold in the bottom 7 metres.The dredge built by Rahco, Spokane, was innovative in a number of aspects but particularly in the fact that a separate ladder with a cutter and pump was used to strip the overburden and a bucketline to mine the gold bearing wash below.Metallurgical studies and exploration were initiated when the project commenced; Leasing and environmental considerations were investigated and action taken.While progress is being made, the operation at this stage is not meeting required production and performance. Main problems have been with the stripping system and wear.

Jan 1, 1990

There has been a substantial transition in the minerals industry R&D environment in the last five to ten years. Changes have occurred in the client and contractor base, the sources and scale of funding, industry imperatives, and competition and collaboration between contractors. These changes are documented from the viewpoint of research contractors in general, and universities and the JKMRC in particular.It is concluded that research groups need to be more proactive in managing their interface with the industry. Both industry and the research community m\lst devote the resources and attention necessary to ensure the effective transfer of research results into operations. The Australian Minerals Industry Research Association (AMIRA) has an important role in these processes, and in regulating the balance between contractor collaboration and competition.

Jan 1, 1996

The scheme of rehabilitation of surface plant commenced in 1936, included the provision of improved and more hygienic changing and bathing facilities for the employees.At that time the Thompson's Shaft section of the British Mine was being prepared for a resumption of operations, and it was decided to repair and re-equip the existing building. Thus any new scheme adopted could be given a thorough trial, and the proved arrangement used as a basis for the contemplated new main changehouse on the North Section.Investigations were carried out to determine the most suitable arrangement for the Thompson's Shaft changehouse, to provide for a total of 120 men, with particular regard to the internal fittings and fixtures. Also, as the mining conditions were such that a large proportion of clothes worn underground by miners, etc., were wet by the end of the shift, the problem of drying these clothes in the availaole time from a man coming off shift to his commencing again some sixteen hours later was one of the most important to be dealt with.The changehouses in use on the North mine section of the lease were provided with racks around the walls for the men to hang their street clothes on, and a section was partitioned off to house the mine clothes and their drying facilities. The actual drying was carried out by means of hanging the wet clothes over racks between which ran pipe coils heated by means of hot water circulated from the hot water boiler supplying the showers.This method had proved to be far from satisfactory for several reasons, the main objections being:-

Jan 1, 1940

During the intial two years (1972 - 1974) of exploration at Telfer, water require- ments were limited to supporting a 50 man camp and diamond drilling to verify thickness and grade of the stratabound ore deposit. Water bores were drilled to intersect the Middle Vale Reef down dip from its outcrop about 70 metres below surface. The MVR reef is an oxidized pyritic horizon which contains 30% - 65% sulphide below the zone of oxidation and forms a highly porous leached gossanous zone to a depth of 100 metres. Surface run-off water from the low hills associated with the Main Dome structure have led to annual re- charge of this extensive aquifer which MAP AREA Lake Waukarlyearly Permian rocks Precambrian basement - - ~;; rocks Sand d.n.s pò. _ « Drainage sg 1 qo~ (`-~.~ ? ò;+ Palaeochannel and 1 d {- subsurface drainage % GLENN BOREFIELD PASSMORE FAULT ;òTsI1. G-OId MIns BOUNDARY oChr~st as t .` Pool 4, 1 j`` Lake Dora òt ~daN 22' 0, 50 Niter KILOMETRES Fig 1. Telfer district map, Great Sandy Desert, Western Australia.

Jan 1, 1988

By R Dunne, S Hart, G Levay

While water represents a major proportion of the mineral pulp processed in flotation circuits, relatively little research effort has been committed to understanding and controlling the influence of water quality on this process. Historically, this probably stems from the perception of water as an inert transport medium. However, the changing attitude towards water as a valuable resource, has given impetus to increasing requirements to use relatively impure make-up water supplies such as treated effluents and a high proportion of internally recycled water. In turn, this has resulted in the need for a more detailed focus on process water quality and its control to minimise adverse effects on sulfide flotation. Along these lines, prior to commissioning of a new concentrator at their Cadia Hill Gold Mine, Newcrest Mining was proactive in examining potential water sources and the influence of water quality on flotation of their copper/gold bearing ore. An extensive water quality survey of all major potential water supplies to the concentrator was undertaken. The flotation performance of the Cadia ore in each of these waters was investigated on a laboratory scale. The results of these studies identified that water quality could indeed have a significant influence on the flotation process. Since operations at the Cadia Hill concentrator began, water quality surveys of both make-up water sources and recycled flotation circuit waters have been carried out on a regular basis. By doing this, a database of water quality has been established which can be compared with plant performance. In parallel with the water quality surveys, a series of laboratory flotation tests have been conducted using a standard ore and waters from various streams to monitor changes in flotation performance as a function of water quality. These tests have indicated that certain water types may have a significant influence on plant performance. More research is required to better understand the impact of water quality on sulfide flotation. This understanding will help operators to minimise adverse effects, while maintaining the best utilisation of available water resources.

Jan 1, 2003

By Johnson N. W, Quast K. B

Over the years there have been occasional references in the literature to the activating effect of cyanide in galena flotation with xanthates. These have usually been associated with the processing of lead-zinc or copper-lead-zinc ores. Bubble contact curves for the pure galena-xanthate system show a flotation edge at pH 10.4 independent of sodium cyanide concentration which was thought due to hydroxyl ion, not cyanide ion.Flotation tests were conducted on samples of Mount Isa lead-zinc ore using varying concentrations of sodium ethyl xanthate and sodium cyanide. At low collector concentrations, galena recovery kinetics improved with sodium cyanide addition, and the higher the cyanide concentration, the higher the galena recovery rate. At higher collector concentrations, galena recovery rate was independent of sodium cyanide addition.For a given collector addition, the lead grade-recovery curve shifted to an improved position with increasing sodium cyanide level. For the same recovery there was an increase in the lead grade with increased sodium cyanide addition, and this increase was most dramatic at high sodium cyanide concentrations.The presence of sodium cyanide during the grinding of Mount Isa ore caused surface passivation of the iron sulphides and possibly the sphalerite.These sulphides, therefore, reacted with less of the oxygen present in the pulp, hence more oxygen was directed to the surface of the galena. This resulted in an enhancement in the total amount of xanthate adsorbed on the galena that is reflected in the improved flotation response of that mineral.

Jan 1, 1990

By Kay JR

In 1984 a new Regional Geological Mapping Program (RGMP) was commenced by the Geological Survey of Queensland (GSQ); the new program was in response to the withdrawal of the Bureau of Mineral Resources from regional mapping. Areas for mapping were selected in northern and south-eastern Queensland on the basis of potential for mineral discoveries, level of company interest, inaccuracies in the first edition mapping and interests of other organisations (government and universities) in joint projects.Geological provinces of particular interest in northern Queensland are the Hodgkinson Basin, parts of the Georgetown Inlier not covered by earlier BMR-GSQ mapping, Broken River Embayment, Burdekin Basin, Lolworth-Ravenswood Block, Campwyn Block and Anakie Inlier. The 1:250,000 sheets covering these areas of interest are shown in Figure 1 including those already completed, those in progress and those planned for future investigation.A flow chart showing the various phases for RGMP projects is shown in Figure 2. Data collection has two facets: (i) field recording and (ii) office work including air photo interpretation, study of company reports, literature research, petrography and various laboratory studies. Two main strands of information collected are represented by a data base and compilation sheets. Compilation sheets are generally at 1:25,000 scale and are available for purchase. The current data base is very fragmentary and can be accessed only by direct contact with the relevant geologist or via written reports. A more accessible field data base is in the process of being introduced this year; this field data base (REGMAP) is based on standardised data recording and computer storage.

Jan 1, 1986

By Collings P. S, Adair D. L

The Upper Robe (Robe Gorge) deposits occur in Kumina Creek and the Robe River, some 20-40 km upstream from mining operations at Pannawonica. The Gorge Deposits were rec- ognised, mapped and sampled in 1962-3 and re- examined in detail in 1971. Approximately 180 mineralized occurrences were mapped in 1971 on 1:4800 scale and 50 of these were remapped in detail at 1:1200 scale. Eighty cross sections were measured and sampled and 300 geological maps prepared. In addition 88 holes totalling 7388 feet were drilled in three occurrences considered to have the greatest potential. The Gorge Deposits occur in the Robe Pisolite unit which forms thin remnant crusts, bay fillings and occasional cut-off meanders along the edge of the present streams. Less than 50 of the deposits have tonnage potential of one million or more. Consequently exploit- ation of the Gorge reserves must be considered as a very uncertain, long range possibility because the deposits are small and scattered throughout the gorges in the area, thereby necessitating costly railroad spur lines to gain mining access. Grade of the occurrences is extremely variable over short distances both vertically

Jan 1, 1973

Trial ore production began at the Hilton Mine in 1987 with ore being trucked into Mount Isa for treatment at the Lead/zinc Concentrator. The expansion of output from the Hilton mine required additional concentrator capacity which led to the design and construction of the Hilton Concentrator. Systematic laboratory and Pilot Plant testwork dating back to 1968 to develop a flowsheet and reagent regime suited to the varied and generally complex mineralogy of the Hilton ore was successfully concluded with a Pilot Plant trial using a sulphoxy based sphalerite depression system in early 1988.In May 1988, a decision was made to build a 750 000 t/y concentrator with some novel technological and capital-efficient features. The Hilton Concentrator commenced operations in December 1989 reaching target grinding rates and metallurgical performance by mid-1990. Current ore treatment rate is 800 000 t/y.Lead concentrates assaying 43 - 48 per cent Pb are combined with the Lead/Zinc Concentrator lead concentrates and smelted at Mount Isa. Zinc and Low Grade Middlings (LGM) concentrates are filtered in the zinc filter plant at Isa with those from the Lead/Zinc Concentrator and then railed to Townsville for export or treatment in Australia.

Jan 1, 1993

By Caivin JS, Freeman CJ

The Fairbanks Mining District in central Alaska was discovered in 1902 and since then approximately 7.5 million troy oz of placer gold, 250,000 troy oz of lode gold, and several thousand short tons of antimony and tungsten hap been produced from an area of about 1000 km . Historic lode production was from high grade gold-quartz veins that averaged 1.3 OPT free milling gold. Five main types of mineral deposits' are recognized in the district. I. Conformable, stratabound volcanogenic zinc, antimony, lead, and copper sulfides in places containing gold, silver and tungsten in bimodal metavoleanics (Cleary Sequence). II. Complex precious metal-bearing lead sulfosalt-quartz veins in Cretaceous granitic intrusives. III. Tungsten skarns adjacent to granitic intrusives. IV. Gold-bearing polymetallic sulfide-quartz veins crosscutting metavolcanics and metasedimentary units of the Cleary Sequence. V. Antimony-bearing gash veins along axial plane shears in various lithologies of the Cleary Sequence. Type I and Type IV mineral occurrences are currently being evaluated as low. grade bulk tonnage (target model 16-20 'million tons of 0.05 to 0.15 OPT)'and high grade moderate tonnage (target model 0.5 to 2.5 million tons of 0.5 OPT) gold deposits. The host rocks for Type I mineralization occur over a 30 km strike length and are at least 300 meters thick. Stratigraphic, structural, fluid inclusion, and isotopic data suggest that the Type IV mineralization is related to remobilization of Type I

Jan 1, 1987

By Smith J. W, Wilkins R. W T

This paper is a preliminary report of research on the Mount Morgan gold-copper deposit being done at the Division of Mineralogy, CSIRO. Fluid inclusion and sulphur isotope measurements were made on a suite of 11 samples collected by the staff of Geopeko Ltd. This suite contained representatives of the main ore and rock types of the deposit. Homogenization temperatures of fluid inclusions measured on quartz from 8 of the 11 samples, ranged from 172¦C to 276¦C and to this must be added a pressure correction (in this case, up to 50¦C) to obtain the formation temperature of the mineral. Sulphur isotope measurements were made on 34 sulphides from 8 of the 11 samples. The 6S values form a well defined group ranging from -0.5%oto +3.6%owith a mean of +2.4%c. Although the preliminary data do not indicate unequivocally the origin of the deposit they do impose restraints on the wide ranging suggestions that have been put forward. This work is complementary to the paper of Dr G. Gibbons who has described other mineralogical aspects of the Mount Morgan deposit, based on a more extensive suite of Samples.

Jan 1, 1974

To reflect on the early history of mining in South Australia requires considerable imagination and rashness. The people who were the chief actors in the scene have long since passed away. Accounts of their activities are hazy and debatable. A broad brush account is all that I can hope to accomplish under these circumstances. It is fitting that a picture be painted and possible lessons learnt from the achievements of our pre- Decessors.

Jan 1, 1987

By Muir D. M

Highly saline process water has a number of implications for the CIP process during the leaching, adsorption and recovery of gold. The reduced oxygen solubility in saline water can seriously reduce the rate of gold leaching, while dissolved oxygen meters do not necessarily reveal actual oxygen concentrations in saline water. High levels of magnesium in the ground water necessitate operation at lower pH (-9), with the potential for greater cyanide loss via HCN stripping. In addition increasing salinity renders viscosity modifiers largely ineffective.The adsorption capacity of aurocyanide onto activated carbon is improved with increasing salinity, but misleading results can be obtained in assessment of gold loading kinetics of plant carbon samples already loaded, or partially loaded, in saline water if subsequently tested in fresh water. Elevated chloride levels in the Zadra elution process can cause severe anode corrosion in the elecuowinning cell. The Anglo elution process is tolerant to only slight increases in water salinity, but elution times can be reduced by ethanol addition. Care is required in carbon regeneration, as salts can catalyse carbon decomposition as well as increase kiln corrosion.

Jan 1, 1994