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The smelting of the Broken Hill lead concentrates at the Broken Hill Asso,ciated Smelters produced, among other products, approximately 4,900 ounces of gold and 8,800,000 ounces of silver during the year ending June 30th, 1938. The following table shows the actual amounts of gold per ton of lead concentrate produced during this period at the important mines. The total gold in the period is calculated from the number of tons of lead concentrates produced, and by comparison with the production' of silver, shows thatthere is no constant relation between the amounts of gold and silver.The fact that no gold is seen during milling, even when gravity concentrating tables are employed, signifies that the gold does not occur as occasional coarse particles.Further, as the values increase considerably in the flotation slime, it can be inferred that the gold occurs as minute inclusions in one or more of the minerals in the lead concentrates.The four most abundant minerals in the lead concentrate are galena, zinc blende, chalcopyrite, and...

Jan 1, 1940

By T Brown

Australia is now committed to the most significant period of infrastructure investment since the 1960s and the current climate of project finance and public private partnership (PPP) model uncertainty means it is imperative that the affordability and certainty in delivery of infrastructure projects is maximised.In light of the current and forecast levels of infrastructure investment it is worth drawing comparison with a similar period of Australian expansion when the nation’s first railways were constructed. Similarly to over a century ago, we are following a trend in rapid development and are already reaping the inefficiencies that could be avoided with broader technical planning and improved client coordination.The original rail networks were developed by the individual states before they combined to form a Federation of states in 1901. As a result of the adoption of different gauges by 1917 a passenger wanting to travel by train from Brisbane to Perth had to change trains six times.Similarly in 2011, there is little parity between Australian states on the quality requirements (performance specifications) for road tunnels. Differences between states start most significantly with the size of the specified traffic envelopes, thus the size of tunnel required. Where ambiguity and differences exist in project documentation, performance specifi cations (PS) and broad technical requirements for road tunnel projects, any associated risk in interpretation ultimately ends up being incorporated in the bidder’s (constructor’s) final sell price.Whilst not nearly as inconvenient as having to change train at each state border, and largely unnoticed by the general tax paying motorist, this paper examines examples of apparent minor differences in Australia’s recently constructed road tunnels to highlight the differences in road tunnel specifications.The paper identifies how these small differences manifest themselves in major price penalties between projects and further, highlights the need for further specification review, refinement and standardisation across road tunnel jurisdictions to increase road tunnel affordability.

Mar 8, 2011

The success of smooth blasting essentially depends on geological condition of rock. Also, in the perimeter hole, borehole pressures with light, well-distributed explosive loads are important to minimise overbreak. In order to simulate perimeter holes with scaled model test, the borehole pressure was considered as a factor of scale. Hydraulic oil pressure is applied as borehole pressure instead of using explosives and detonators in order to remove the undesirable effects of detonators in an experimental set-up of just two perimeter holes in a tunnel blast. The borehole pressure on a perimeter hole is nearly reproduced with hydraulic pressure which is generated by non-electric detonators in the hermetical cylinder.

Dec 6, 2010

The first part (lH of this work dealt with the process of recrystallization of single crystals of lead after deformation by creep, as revealed by macroscopical examination. It was shown that when recrystallization commenced, a crystal, termed the primary crystal, started to grow at the edge of the specimen and extended into the body of the specimen along the slip planes. At some stage during the growth of this crystal, other crystals appeared at the boundary of this first crystal and fragments of the parent crystal. From thispoint, recrystallization was accelerated with relatively rapid necking down of the specimen until fracture occurred.All those crystals formed after the primary crystal were given the term secondary crystals. In the present paper is given a detailed account of the orientations of the primary and secondary crystals.EXPERIMENTAL METHODThe size of the test pieces and the manner of loading were given in the previous paper (1). X-ray back reflection photographs were taken of the individual primary and secondary crystals and from them were determined the orientations. The path of the X-ray beam was perpendicular to the surface of the creep specimen.In view of the large number of photographs needed, gold...

Jan 1, 1940

Geological hazards such as faulting, basement ridges, and zones of "thin" (< 6 m) coal have a major impact on mining economics of underground operations in Huntly Coalfield. Experience has shown that drillhole-based investigations do not yield sufficiently detailed models of the coal seam to allow management of the planning risks associated with these hazards. Consequently, operational performance is affected by unplanned costs associated with lower productivity, loss of coal reserves, and expensive strata control remedies in problem ground conditions. Huntly Coalfield is a challenging environment for acquisition of good quality seismic reflection data due to the very thick (10-85m) weathering layer. Since 1994, successful acquisition of 2D and 3D data has been achieved through a combination of careful testing of technical parameters and experimental trials prior to committing to production recording. High resolution seismic reflection (HRSR) is proving to be an investigations technique which generates accurate and reliable models of the coal seam and associated structures, such as normal faults and topography of the surface on which the coal seam rests. The HRSR technique has been applied and developed in the Okowhao Sector where Huntly East Mine is developing and extracting coal reserves. Results of a recent 3D survey demonstrate that this technique is capable of revolutionising risk management in mine planning for underground mines in structurally complicated coal deposits.

Jan 1, 1997

The methods and equipment developed and used at the Mount Isa mine to obtain samples of uncemented hydraulic fill lying above major horizontal pillars are described. From existing underground development, samples were obtained at distances up to 50 m, of which up to 30 m was through hard rock. Samples were used to predict fill behaviour as it affected mining security during recovery of the pillars.Specialized equipment for difficult sampling situations and also other sampling exercises are described.

Jan 1, 1976

This evening I intend to explain the position of the gold mining industry in the light of post war trends and events.I propose initially to comment on gold production throughout the World and then proceed to the state of the industry in Australia, with an account of the efforts made within the industry to maintain levels of production. This will be followed hy a statement on assistance granted to the industry by Federal and State Governments.Annual World gold production is estimated at 51,000,060 fine ounces, made up as followsSouth Africa - 27,300,000 fine ouncesCanada 4,200,000 " "U.S.A. 1,500,000 " "Australia - 1,000,000 " " Others 5,000,000 " "----- 39,000,000 " "Estimated Russianproduction - 12,000,000 " "Total 51,000,000 " "The opening up of new highly payable mines during the post war years has contributed to the preponderence of production in South Africa.In 1962 some 24 new mines produced 73 per cent of South Africa's gold, and contributed almost 90 per cent to the industrial profits.At the same time, 20 old mines were struggling to main...

Jan 1, 1964

By Whitmore R. L

The action of water on a number of Queensland shales which are associated with particular coal measures and oil shales has been studied. The results suggest that the disintegration of some of the shales could cause significant problems in mining and preparation operations. The extent of shale breakdown varies widely from deposit to deposit and from seam to seam but a suitable assessment procedure utilises the test described in AS 1661-1979, and an improved method of presenting the results is described in the paper.

Jan 1, 1982

The material presented in this paper describes experimental work to determine the effect of variations in suction nozzle design upon inlet flow conditions. Four entrance profile shapes were examined under controlled conditions of slurry flow and it was found that the straight ended nozzles had consistently higher entrance losses than the straight taper or the ellipse, and that the circular arc profile nozzles were the most efficient. Subordinate considerations were the measurement of the quantities and the forces involved.As the work progressed, three distinct phases in the pattern of flow were apparent and the static pressures in each were carefully examined. An inlet zone was found to be unstable in changing boundary conditions, a transition zone was largely independent of slurry density and in a zone of stability the pressures were found to be directly related to the characteristics of the flowing pulp. In this zone pressure measurements were reproducible within ± 2 per cent regardless of changing boundary conditions.The effect of varying the "1" parameter of nozzles with a part circular entrance profile was examined and it was found that flow conditions approaching the ideal were obtained when the radius of curvature was between 0·40 and 0·550.

Jan 1, 1966

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

By A Paz, H Lehto, M +stholm, I Roitto

Nowadays, the demand for a finer grind in minerals processing has set new challenges within the industry, particularly for grinding technology. Apart from a finer grind, energy efficiency is also a key driver in optimising comminution technology.Stirred milling technology, already proven in many other industries, delivers a modern, sophisticated, flexible and energy efficient grinding solution for fine and ultra fine grinding in minerals processing. Fine grinding technology is utilised particularly in concentrate regrinding to complete the liberation of valuable minerals after the first stage of concentration. Maintaining the correct particle and particle size distribution of the regrind product is crucial for downstream process performance. Stirred milling technology offers the unique possibility for online control and optimisation of the regrind product particle size. This paper describes the basis of this online control possibility and discusses the implementation of stirred milling technology in minerals processing, particularly in regrinding applications. The paper will also outline management and control of fluctuations in feed rate tonnages as well as particle size fluctuations in concentrate regrinding.CITATION:Roitto, I, Lehto, H, Paz, A and +stholm, M, 2013. Stirred milling technology - A new concept in fine grinding, in Proceedings MetPlant 2013 , pp 190-201 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

The structure of the Bulli coal seam at Appin Colliery was detailed by the seismic reflection method. This unusual application of the seismic method was possible because there is a reflector near the seam as was revealed during exploration for petroleum in an area north-west of Appin. The reflector, which was at a depth of 1,500 ft, was shallow by normal reflection survey standards. Measurement of the seismic velocity at two ventilation shafts showed that the reflector was probably the Bulli coal seam. Accurate depth control was established from previous drilling results.INTRODUCTIONAppin Colliery, situated on the Southern Coalfield of N.S.W. (Fig. 1), is being developed to supply coking coal to the Port Kembla steelworks of Australian Iron and Steel Pty. Ltd. The colliery is mechanized and a detailed knowledge of structure, particularly faulting, is important in planning the workings.The Bulli seam, which is approximately 9 ft thick, and between 1,500 ft and 1,800 ft below the surface, is worked in the colliery. It is the uppermost member of the Permian Coal Measures and is overlain by Triassic rocks, which consist of thick sandstone beds containing beds of coloured shales, and which are subdivided into the Narrabeen Group, the Hawkesbury Sandstone, and the Wianamatta Group.In the early stages of development of the colliery, surface geological mapping and diamond drilling provided information on structure. Generalized results of the mapping are shown on Fig. 2. Drilling indicated that the physical and chemical properties of the Bulli seam are relatively constant, and that the seam is nearly horizontal, the average dipbeing about 1 in 25 to the west.

Jan 1, 1965

Experimental Validation of a Flotation Cell Model

Sep 13, 2010

Essential features of the role of the fill material in mechanized cut and fill mining are discussed, with particular emphasis on its dewatering and strength development after emplacement. The fill material is regarded as a chemically-reactive porous medium, the most important property of which is permeability. Methods are described for measurement of permeability and other fill properties and results of such measurements applied to develop an orderly approach to the operation.

Jan 1, 1966

Throughout history, many of the world's achievements, conflicts and problems can be traced to the demand for minerals. With the rapid expansion of our industrialised society in recent years the demand for minerals has grown to such an extent that uncertainties about availability and cost have arisen, especially in the case of energy minerals.Minerals have acquired a new dimension for governments as the availability of these resources is interwoven with the ability of governments to achieve their developmental goals on national and international levels. Accordingly, the supply of minerals will increasingly be affected by social and political factors.

Jan 1, 1986

By D Pilone

The Tyrrhenian micro-nodules, findable at low depths (200/600 m under s l) are a reasonable reserve of manganese. They can be easily and cheaply recovered but do not contain valuable metals as in the case of oceanic nodules. In this work a hydrometallurgical process for manganese recovery from Tyrrhenian nodules is presented. The studied treatment includes the following operations: magnetic enrichment, reducing leaching, leach liquor purification and electrowinning . The study shows that the most important step in the process is the preliminary manganese enrichment. It can be done directly on the platform reducing not only the transport cost, but also the residue mud in the metallurgical plant. The leaching parameters such as status and size of nodules, temperature, composition of leaching solution and S/L ratio have been investigated. After purifying the leach liquor by iron precipitation as ammonium jarosite , the conditions to electrowin manganese have been investigated. The yields of both manganese leaching and iron precipitation together with current efficiency and specific energy consumption in the electrowinning step are given.

Jan 1, 2000

BATMINÖ, BATMINEÖ, BATMINDÖ are an abbreviation for Business Analysis Tools for Mining, Mine Evaluation and Mine Design respectively. BATMINP are proprietary tools customised to suit individual client requirements. The first suite of tools provides for analysis and evaluation of open pit mining equipment alternatives and includes fleet selection, fleet sizing and production, productivity and economic outcomes. The models address all mine process activities including drilling, blasting, loading, hauling and auxiliary services. All models are built to provide for simultaneous evaluation of multiple alternatives that are time and condition related. Provision is made for modelling from first principles and/or default or shortcut inputs. Sensitivities to key input parameters are easily performed and consistent logic is applied throughout the process. The models are built to provide key outputs in a format suitable for presentation and documentation. Provision is also made in the models for validation of both inputs and outputs through benchmarking, back analysis and budget comparison. The same models can be used for short interval (12 month) planning and control, medium-term (three to five years) and long-term life-of-mine (LOM) planning. Millions of dollars are spent each year on mining plant and equipment. Decisions that impact on the medium and long-term are made. BATMINP tools have been used to perform studies with good results and in most cases the studies have been validated through back analysis and comparing model outcomes to real data.

Dec 6, 2010

By Sie A

After completing a feasibility study in 1987, Niugini Mining Limited (NML) obtained five Gold Mining Leases within PA 632, covering the Mount Victor and Clarkes Ridge gold deposits. Reserves prior to mining were 260 000t at 3.63g/t Au for Mount Victor and 40 000t at 2.8g/t Au for Clarkes Ridge. Ore was mined from the two deposits by NML from November 1987 to January 1990. A total of 645kg of gold and 346kg of silver were produced from 198 000 tonnes of ore pro- cessed. Mining and milling operations ceased in February 1990. Since then, there has been significant progress in rehabilitating and revegetating the site. Plant and workshop facilities have been dismantled and removed from site, exposed parts of the pit have been landscaped and replanted, tailings water has been neutralised and discharged, and the dam filled. All remaining personnel and equipment left the site in November 1990. It is envisaged that the replanted areas will be rapidly revegetated, leaving little evidence of mining. Niugini Mining did not recoup the initial investment for Mount Victor, but the mine produced a positive cash flow and made a significant' financial contribution to the local communities and Papua New Guinea as a Whole.

Jan 1, 1991

By D Cork, R Peet

"Methane is a signifi cant greenhouse gas. Methane is released from coal seams during the mining process, both in surface and underground operations. This uncontrolled release is termed æfugitive emissionsÆ and in underground mines is transferred to the atmosphere in ventilation air, known as ventilation air methane (VAM). The global VAM emissions are over 369 Mt of CO2-e/a (Butler, 2011; US EPA, 2010). Coal mines may abate this VAM or consider abatement should there be a price on carbon. These fugitive emissions are heading towards ten per cent of AustraliaÆs emissions by 2020 (Department of Climate Change, 2011).There are safety issues involved in VAM destruction. Due to the nature of coal, and coalextraction, unpredicted methane spikes above the lower-explosive-limit (LEL) can occur in theventilation air; for example outburst events or ventilation failure. This could lead to a mine fi re ifthe mine ventilation air was connected to a VAM abatement plant and the risks are left unmitigated.CorkyÆs is working with the mining industry to directly address these safety issues. CorkyÆs calltheir technology VAM RAB, which stands for ventilation air methane regenerative afterburner(VAM RAB). VAM RAB utilises the principles of a thermal oxidiser.This paper discusses fi ve independent layers of protection (ILPs) to fi rst stop methane reachingthe thermal oxidiser and secondly prevent the fl ame front from burning away from the VAMRAB. The test work completed or contemplated includes safety integrity level (SIL) assignmentto various vents, barriers and door systems to prevent a fl ammable mixture reaching the VAMRAB, proven rapid response methane monitoring sourced from the petrochemical industry, anddefl agration experiments to test the eff ectiveness of the passive geometry and active engineeringcontrols. These experiments and SIL assessments indicate that it is possible to safely connect theVAM RAB to a working coal mine.Further work is required to upscale the pilot safety work. Refi nement to the design is possible;for example improvement to safety duct controls once trialled at demonstration scale plus thermalenergy capture for power generation or other applications to provide heat. Nevertheless, thispaper shows how safety issues can be managed by a multilayer of protection approach usingvents, barriers and doors, and appropriate thermal oxidiser geometry."

Jun 1, 2012

By I T. Ross

In the last 50 years there have been tremendous improvements in equipment used in development on underground mines. Compressed air powered jacklegs have been replaced by high powered electro-hydraulic drifters on sophisticated drill jumbos and load haul dump units have taken over from small shovels and rail cars.Despite the increase in power applied in key parts of the development cycle, average advance rates have fallen and costs have increased. The factor that is most often regarded as the main contributor to slowing advance rates is increased support requirements. Whilst there is no denying that the drive to improve safety has resulted in the requirement for more bolting and the installation of a skin support (mesh or shotcrete), this is not the only factor.Within the industry as a whole, many of the basic principles of development appear to have been lost over time. This paper looks at a historical case study and discusses some of the features of old development cycles that are no longer in use. This highlights some of the basics that appear to have been forgotten. These may be indicators to what may provide improvements in the conventional drill and blast development cycle.CITATION:Ross, I T, 2014. Development – back to basics, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 67–74 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014