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Mining companies in order to compete and succeed in being viable business propositions must look to the future and select mining methods which guarantee improved efficiency and productivity as well as lower costs. A mining company in adopting a method of mining must now select the equipment most compatible. To some mines compatible equipment may mean the use of drilling jumbos to replace hand held rock drills or the use of load haul dump units to replace scrapers. To other more mechanised mines compatible equipment may mean the use of raise borers and road heading machines. The right decision will be where equipment compliments method in such a way that the working environment is improved, productivity is maximised, cost if reduced and all profit opportunities are optimised. An example of such is where the use of improved mining techniques in underground operations may see cut off grades reduced. By selectively mining these lower grade orebodies, smaller operation's ore reserves improve and the capacity for continued growth is enhanced.

Jan 1, 1990

By P S. Heithersay, M McGeough

The discovery of Olympic Dam in 1975 and, more recently, Prominent Hill in 2001 and Carrapateena in 2005 demonstrates the potential for world-class IOCG deposits in South Australia. Potential for further discovery of large IOCG mineral deposits in the Gawler Craton and the Curnamona Province is high because of continental-scale pervasive iron-rich alteration, crustal-scale structural preparation and unique magmatic-hydrothermal conditions. Recent exploration successes point to the effectiveness of new exploration tools and technologies to locate this style of mineralisation under cover. The gold endowment of these orebodies located in South Australia exceeds 75 Moz, with further discoveries to come. The lead time between discovery and development of the multi-million ounce Prominent Hill copper-gold mine in less than seven years demonstrates how quickly this style of deposit can be brought into production in South Australia. Clearly these long-life, multi- commodity IOCG deposits mines are an immediate exploration and future growth opportunity for the gold mining industry to replace ever depleting gold inventories.

Jan 1, 2007

By N Guresin, R Dunne, S Blanco

This paper presents the results of research work conducted to assess if aqueous solutions of sulfur dioxide (SO2) can be used to treat roaster calcine leach residues such that recovery of gold in this material can be achieved with subsequent application of the thiocyanate (SCN-) leaching system. The project is mainly aimed at assessing an alternative use for sulfur dioxide gas generated during flotation concentrate roasting. The calcine leach residue sample used in the study contained 2.56 g/t gold. The reason for this high level of residual gold is thought to be due to gold surface passivation by thin iron oxide films, presence of gold in solid solution with refractory iron oxides and encapsulation of gold in the structure of these iron oxides.The study was conducted in three stages. The first stage was the characterisation of a sample from a roaster calcine leach residue. The second stage in the project was a set of leaching tests to assess the feasibility of using aqueous solutions of sulfur dioxide to reductively dissolve refractory iron oxide mineral phases contained in the calcine. The final objective was to assess the efficiency of thiocyanate, a gold complexing ligand stable under acidic and oxidative conditions, to extract gold liberated during sulfur dioxide leaching.The study showed that the reductive sulfur dioxide treatment of the calcine leach residues followed by oxidative thiocyanate leaching to extract gold was not a particularly efficient process as only around 20 per cent gold could be extracted. Leaching the calcine residues by any of these systems separately also extracted the same amount of gold (12 - 14 per cent) implying that irrespective of the solution potential, the acidity helps dissolution of gold encapsulating minerals, mostly hematite, but at a very slow rate. The findings on the topic in the literature and during this study show the requirement for further technical investigations and economical analyses on two cases. The first case is to roast gold concentrates to produce magnetite rather than hematite followed by sulfur dioxide and thiocyanate leaching of magnetite containing calcines. The second case is to apply a magnetic concentration process to conventional roast-cyanidation calcine residues to produce a gold-rich magnetite concentrate that can be further treated with sulfur dioxide followed by thiocyanate leaching.For both cases, the best evaluation of the sulfur dioxide leach system in extracting residual gold from calcine leach residues will require a detailed economic analysis to find out the balance between the value of the gold recovered and the loss of revenue from acid production. There are a number of roasters that do not produce acid. In these cases, a portion of the unwanted sulfur dioxide gas can be used to recover gold in magnetite containing calcines as an economic incentive.CITATION:Guresin, N, Blanco, S and Dunne, R, 2013. Leaching roaster calcine leach residues with aqueous solutions of sulfur dioxide and thiocyanate, in Proceedings World Gold 2013 , pp 129-136 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

Following extensive trials on a 100 000 tpa Research and Development facility at Kwinana, Western Australia, Hismelt Corporation (wholly owned by Rio Tinto) are confident of the future commercial success of this technology. The Hlsmelt process uses iron ore fines and non-coking coals to produce molten pig iron suitable for feeding to BOF and EAF steelmaking vessels. The unique process configuration combines direct injection of raw materials into the molten iron bath, high rates of metal and slag mixing, and effective post-combustion of the bath gases to achieve efficient coal utilisation. This is the key to the strong economic performance of the process.

Jan 1, 1999

Reasons are given for the seemingly excessive public concern with taxation of the mineral industry. Optimality of mineral extraction is a concept that requires careful definition in terms of one or more objectives. Once defined, the impact of taxation upon optimal mineral extraction may be studied; findings from earlier work on this topic are presented for two basically different cases. In conclusion it is observed that the pursuit of optimality requires the availability of highly skilled engineers; in the event of a large-scale mineral development it is this resource that is probably scarcest of all.

Jan 1, 1983

The flolation behaviour of some Australian uranium ores was investigated. Although uraninite and pitchblend float readily with fatty acids, selective concentration to produce an economically discardable tailing has not yet been achieved. This is attributed to the presence in the ores of a quantity of uranium mineral in finely dispersed form which is very difficult to liberate. For some of the ores, at least, the proportion of this material decreases with increase in head assay.Flotation may be a useful concentrating method for some Australian ores if uranium oxide is to be sold in a free competitive market.

Jan 1, 1967

By J Guo, K Williams, S Caldwell, W Chen

Mining is increasingly occurring near or below the water table. This has led to a higher rate of handling problems associated with increased moisture and increased adhesion, which lead to a higher rate of blockage events within the materials handling chain. Typically, these ores and minerals are known as ‘wet and sticky materials’.Currently there is very limited knowledge and/or methodologies for effective design of efficient materials handling systems when it comes to handling wet and sticky materials. However, there is one major parameter that significantly affects handleability of a wet and sticky ore; namely, its moisture content. Flow property testing has shown that when moisture is reduced, the adhesive properties of the ore are also significantly reduced, thereby increasing ore flowability.The research embodied in this paper investigates the moisture reduction rate through a loose packed bed of iron ore using dry, ambient temperature airflow. A comparison of the predictive capabilities of a proposed drying model to data obtained from on-site experiments using iron ore fines is made. Building on an assumption made by Hukill (1954), a second term has been proposed to account for rewetting effects in the drying process. From this research, identification of improved moisture reduction approaches is envisaged.CITATION:Caldwell, S, Williams, K, Guo, J and Chen, W, 2017 Aeration induced moisture reduction of iron ore, in Proceedings Iron Ore 2017, pp 455–460 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

The theme of this conference is æRediscover OtagoÆ and the conference occurs during a resurgence of economic activity in New Zealand, and in particular at a time when the Macraes Gold Project has had a significant effect on mining and business activity in Otago. The Macraes Gold Mine has implemented a Zero Accident Programme and this paper reviews some of the factors responsible for the implementation.

Jan 1, 1992

By D Craw, L C. Kerr, P Wopereis

Gold placers in the Nokomai and Nevis valleys are dominantly Quaternary in age. They occur mainly in western tributaries of the upper Nevis, eastern tributaries of the middle and upper Nokomai, and in the trunk valleys themselves. Placer gold in both valleys is dominantly a-phase Au-Ag-Hg alloy. Au-Ag alloy is absent or rare in most of the deposits, except in the lower Nokomai. Alpha-Au-Ag-Hg alloy is typically coarse-grained (up to 2 cm), angular, and rarely flattened or folded. Crystalline texture, quartz intergrowths, and psuedo-hexagonal crystal-pluck cavities are common. Fluvial transport distance predicted from the maximum Flatness Index ofAu-Ag-Hg alloy particles is typically less than 10-20 km. Coarse (up to 2 cm) cinnabar is commonly associated with the Au-Ag-Hg alloy, and both were probably derived from hydrothermal sources in western tributaries ofthe upper Nevis and eastern tributaries of the upper Nokomai. Minor secondary Au-Ag-Hg alloy occurs locally in the lower Nokomai, where it coats or cements detrital a-phase Au-Ag-Hg and Au-Ag alloy particles. Au-Ag alloy dominates over Au-Ag-Hg alloy in the lower half of the lower Nokomai alluvial plain and gravel of a raised channel incised into semischist basement adjacent to the plain. The Au-Ag alloy is rounded and commonly flattened and folded. Crystalline texture, quartz intergrowths, and pluck cavities are rare, and a fluvial transport distance of 25-40 km is estimated from maximum Flatness Index ofAu-Ag alloy particles. The Au-Ag alloy, three types of gamet, magnetite, clinozoisite and well foliated schist boulders in the abandoned channel are not found in the pumpellyite-actinolite facies bedrock in the Nokomai. These components were derived from greenschist facies schist and sedimentary sources in Otago, many tens of kilometers north of the Nokomai catchment. They were transported to the Nokomai either in Wakatipu Glacier till or fluvio-glacial outwash that entered the valley via Nokomai Saddle, the confluence with the Mataura, or both.

Jan 1, 2000

By T A. Helms, P Gottlieb, S E, R Bateman

In response to the ever-increasing challenges facing the modern gold mining industry and the need for improved gold recoveries within all processing streams, CSIRO has upgraded its latest automated mineralogical analysis system, QemSCAN (formerly QEM*SEM), with special purpose hardware that speeds up the location and measurement of precious metal-bearing phases. By rapidly scanning the surface of polished blocks, and accepting only fields that contain the minerals of interest, QemSCAN is able to find, map, and quantify target minerals in extreme detail. Phase identification and quantification is achieved by placing a grid of points over the target particle and collecting X-ray information at each analysis point. The resulting mineral maps provide the metallurgist with a complete textural description of all gold-bearing phases within the product measured, together with quantification of the gold phases in terms of their modal abundance, particle size, mineral associations, relative contributions to gold deportment and liberation characteristics. Examples are presented which illustrate how QemSCAN is able to find and quantify gold-bearing phases within low-grade ores from the Super Pit, Kalgoorlie. This work is the result of a collaborative project between Kalgoorlie Consolidated Gold Mines (KCGM), CSIRO Minerals, and the University of Queensland, and is on-going.

Jan 1, 2000

By D Bradshaw, R Dunne, S Farrokhpay

It is well known that clays affect the flotation performance, and many of the refractory gold ores around the world contain clay minerals. Therefore, an ore sample from the Carlin Trend was selected for this study as these ores contain large quantities of clays. The presence of clay minerals in an ore makes it susceptible to a range of variables, such as the solution chemistry determined by pH and the chemistry of the rheology modifiers. The viscosity of the ore slurry was measured as a function of solid concentration and particle size distribution, in addition to using different rheology modifiers and pH regulators. The results were correlated with the ore flotation performance. It was found that various reagents known commonly as dispersants or rheology modifiers have different effects on the ore slurry viscosity. This study revealed that the gold flotation recovery can be improved by changing the pulp rheology.CITATION:Farrokhpay, S, Bradshaw, D and Dunne, R, 2013. Rheological investigation of the flotation performance of a high clay containing gold ore from Carlin Trend, in Proceedings World Gold 2013, pp 333-340 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By R G. Richards

The Australian glass sand industry produces some 2.8 million tonnes per annum of silica sand, of which about 2.0 million tonnes are exported and the rest is for the domestic market. Approximate production rates for each Australian state are listed. The variety of processing methods used in the currently exploited deposits reflects the size, location, and characteristics of the various deposits and the requirement of the end market/s. The industry uses to a large extent equipment developed for the separation of mineral sands, particularly as it applies to low grade heavy mineral deposits, where low cost, high capacity and metallurgically efficient equipment has proved eminently suitable for the production of the low value glass sands. The requirements of the domestic market, as well as those of the present and potential export markets are discussed covering quality requirements, distribution channels and other factors critical to success.

Jan 1, 1990

IN carrying out experiments to determine the amount of metal taken away by fume or fine dust the apparatus used requires to be strong and compact, as it is generaIIy necessary to work on a staging fixed at considerable distance above the ground and against a smoke stack or flue. It is essential that the test be carried out at a part of the stack welI away from any bends, to prevent eddies. The method described below has been used for estimating the dust losses from Dwight & Lloyd sintering machines, antimony drossing furnaces, pot sintering trials, etc., and has been founc! satisfaetory. It is welI to bear in mind that the longer the period over which dust coIIection is extended, the more valuable the result is likely to be. The rateof aspiration of the gases through the apparatus is kept as regular as possible by changing the filter thimbles frequently, and the rate of flow should correspond closely with the rate of flow of the gases up the stack.The apparatus required for carrying out a test is as folIows :-{a) Thermometers : two are required, one for taking the temperature of the gas in the stack and one for giving the temperature of the gas in the aspirating drum. If the temperature in the stack is over 400° C., it is advisable to use a pyrometer such as the "Bristol" the couple being standardized before use at about the temperature of the stack.(b) Pilot Tube: The foIIowing sketch (Fig. 1) iIIustrates the principle of the pitot tube. The readings are to be taken in a straight flue, or stack, preferably 20 diam. away from any bend. A, which is open, faces the air current and...

Jan 1, 1922

By J T. Carswell, K Sutton

Quality control (QC) of reverse circulation drill sampling commonly involves regular duplicate subsampling to monitor the extent of imprecision or random error in the subsampling system. In gold mining in Australia, the subsampling tool is usually a cone splitter.Other sources of error, including delimitation error and bias (systematic error) in the subsampler are often assumed to be negligible or ignored for being too difficult to QC.This paper describes actual sampling errors and error mitigation based on quality assurance and quality control (QA/QC) of surface and underground reverse circulation drill sampling at a high-nugget gold mine at Sunrise Dam, Western Australia.CITATION:Carswell, J T and Sutton, K, 2014. Sources of sampling error and implications for quality assurance and quality control in surface and underground reverse circulation drilling, in Proceedings Sampling 2014 , pp 65–70 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 29, 2014

Characterisation of Manganese Ores

Sep 13, 2010

PIP is regularly engaged in businesses where Greenfield Capital Projects are under- delivering on the expected business case. In most of these projects, we can identify that rigorous review has been carried out on the design and financial cost elements and substantial reporting is maintained to Boards on progress versus plan of project completion and cost. However, in all sites of this nature that we have worked at, the planning, design and execution of the operational elements or æwiringÆ of the organisation have fallen short and resulted in significant extra cost or opportunity cost (lost tonnage or quality) during start-up. When compared to the amount of planning and resources that have been poured into the capital side, the ledger on the æwiringÆ side is typically fairly sparse. This presentation outlines the importance of running a disciplined, rigorous process to prepare the human and wiring side of a start-up to ensure rapid start-ups and put the site on the pathway to high performance. It gives an outline of the rigorous process PIP has used with projects to ensure excellent start-ups.

Jan 1, 2006

By Muller M, Ashley PM

Massive sulphide ZnPbCuAg deposits in the Halls Peak district of northeastern NSW are of the submarine volcanogenic type. They occur as a number of small lenses enclosed in shale and epiclastic rocks, in association with felsic volcanics of early Permian age. The deposits crop out in steep terrain near the eastern edge of the New England plateau. Local relief of 700 m and slopes up to 50¦, coupled with an average annual rainfall of about 1000 mm has led to local severe landsliding in previously mined areas. Mining from the 1890's to the 1960's has also resulted in unconstrained drainage of heavy metal-bearing acid waters and physical dispersion of finer grained metalliferous sediments into the Chandler River. Waters emanating from the main landslide area, from underground workings and draining scattered unconfined stockpiles of massive sulphide ore have pH values of 3 to 4 and contain elevated contents of Zn, Cu, Pb, Cd and Fe. Chemical mobility of heavy metals into streams occurs under low pH conditions with Zn exhibiting the greatest dispersion. Increasing pH conditions downstream cause precipitation of Fe phases and coprecipitation of heavy metals. Physical dispersion of secondary metal-bearing minerals into the surrounding creeks results in wt% levels of Cu, Pb and Zn in the stream sediments thereby exceeding the regional background values by one to three orders of magnitude. Areas disturbed by mining are characterised by lack of vegetation, biomagnification of heavy metals into algae and lower plants, and partial recolonisation by metal-tolerant grass species (Snow Grass, Poa sieberana; Blady Grass, Lomandra longifolia). Rehabilitation measures will have to include landslide stabilisation, impervious sealing or removal of sulphidic materials, import of topsoil and revegetation by metal-tolerant, slow-growing native grass and shrub species.

Jan 1, 1995

By B Twidle, D Bertoldi, J Meikle, R Dunne

The Waihi Gold Mine is situated in a high rainfall area (annual average of over 2 m) on the North Island of New Zealand. Water treatment and discharge at the mine has been ongoing for the last 25 years. The first water treatment plant consisted of a æstandardÆ water treatment facility (ferric chloride precipitation) and cyanide detoxification. With time the project has expanded and the volumes of water increased requiring additional treatment methods (reverse osmosis) to meet the water quality for discharge. This paper will provide information on the historical development of the water treatment flow sheets, performance data and operating costs.CITATION:Bertoldi, D, Dunne, R, Twidle, B and Meikle, J, 2013. Water treatment at the Waihi Gold Mine, in Proceedings World Gold 2013 , pp 503-508 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

Pipe Flow Stability of Concentrated Coal-Water Suspensions in the Presence of an Electric Field

Sep 13, 2010

Separating Particles by Horizontal Deflection in a Paramagnetic Fluid This paper describes the horizontal deflection behavior of particles in paramagnetic fluids under a high-gradient superconducting magnetic field. Movements of single particle were observed experimentally and indicated that they could be deflected to different positions. Based on these results, the behavior of groups of particles from ore samples was examined in the superconducting magnetic. It was found that these particles could be deflected and settled at a certain position due to the combination of gravity and magneto-Archimedes forces as well as a lateral buoyancy (displacement) force. Mineral particles with different susceptibilities and/or densities could be deflected to different positions, thus producing groupings of similar types of particles. The work described here, although in its infancy, could form the basis of new approach to separating particles based on a combination of susceptibility and density.  

Sep 13, 2010