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By Baczynski NR, Fagan MJ

A 3050m long section of a 1.65m internal diameter tunnel is presently under construction in the Brisbane area by means of the pipe-jacking method. The soils along the alignment had been deposited in a deltaic/estaurine environment and rapid changes in soil type occur. The tunnel passes beneath several extensive bodies of surface water. Groundwater problems have been experienced with tunnelling through alluvial sands and gravels. Details of the ground conditions, the pipe-jacking method used and tunnelling experience are discussed in this Paper.

Jan 1, 1987

By J W. Hedenquist

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Epithermal deposits (Au or Ag dominant, ± base metals) form within ~1 km of the surface in volcanic belts, both arcs and rifts, with the different tectonic settings reflected in distinctly different characteristics. Within arcs, deposits are typically intrusion centred and commonly associated with hypogene advanced argillic alteration, both in lithocaps and as halos to shallow or proximal portions of some veins; such alteration is coupled with processes that form porphyry Cu-Au deposits at depths of ~1–3 km. Introduction of metals is related to the subsequent phyllic-stage overprint; if this fluid rises to the level of the lithocap or into epithermal veins, Au mineralisation with Cu or Ag may occur, associated with sulfate minerals or muscovite. By contrast, Au-rich (both low Ag:Au ratio and bonanza grade) colloform quartz veins form at shallow depths in volcanic rifts, typically within a few hundred metres of the surface, with clay halos and topped by silica sinter if the palaeosurface is preserved. The geologic variability in volcanic belts, including host rocks, structures and hydraulic gradients, means that many epithermal deposits vary from the end-member features of the principal styles. Effective exploration requires familiarity with end-member styles as well as potential variations, plus the mineralogical indicators of palaeotemperature (eg evidence for erosion depth, fluid flow channels). This knowledge helps the geologist in the field to imagine what might be buried and where, and how to best test the target with drilling.CITATION:Hedenquist, J W, 2015. Recent developments in understanding of and exploration for epithermal deposits in volcanic arcs , in Proceedings PACRIM 2015 Congress, pp 11–16 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

New Bio-Adsorber with Activated Carbon and Nano Tube Carbon for Separation of Nickel and Cadmium

Sep 13, 2010

INDEX OF CONTENTSIntroductionChemical compositionsNormally Cooled MattesPort Kembla mattesMount Lyell matteMount Morgan matteGranulated MattesConclusionsIllustrationsINTRODUCTIONIn a previous paper in these Proceedings(l) an account was given of the composition of some copper-lead mattes from the Port Pirie Smelters. The research programme of the Mineragraphic Section of the Commonwealth Scientific and Industrial Research organization has since been extended to copper-iron mattes from Port Kembla (The Electrolytic Refining ana Smelting Co. of Australia), Mount Lyell (The Mount Lyell Mining and Railway Co.) and Mouilt Morgan (Mount Morga:p. Ltd.).Chemical Composition of the Mattes.The mattes examined have a considerable range in chemical composition, as is shown by their analyses (Table 1).

Jan 1, 1949

The first hydraulic roof supports were installed underground in 1950s and ever since that time engineering developments have improved the supports in many different ways. However. advances in three main areas, the roof support mechanical design, hydraulic engineering and electronics have ultimately led to the point where, 35 years after that first installation. automation has been achieved and is now commonplace.The history of roof support automation has involved the continual integration of high technology engineering. Thera ate further possibilities for the future which combine to give some idea of the likelihood of there ultimately being a completely manless face.

Jan 1, 1991

The optimum plant capacity for a new mine is usually based on empirical studies or ærules of thumbÆ, subject to confirmation by detailed scheduling of the proposed mining operation. The mining industry has a record of poor returns on investment and a high rate of project failure using these methods, with under-performance in grade being a common experience. The assumption that æeconomies of scaleÆ will result from increasing throughput rates needs to be balanced by an awareness of the adverse effects of increasing the rate beyond a level that issupportable by the resource. For each scale of operation considered, it is a reality that for any intended head grade, at the associated intended cut-off grade, the actual head grade achieved will fall as the mining rate increases. This effect is known to people at operations but is not recognised in current ore reserve estimation methodology. Once recognised, this dependency of head grade on mining rate can be quantified and used to establish the economically optimum mining and processing rate for a new project. A simple analysis is proposed, which may be extended to detailed spreadsheet modelling for financialoptimisation.

Jan 1, 2002

By E Yll÷, O HyvSrinen

Outokumpu has developed a new chloride leach process, called HydroCopper«, to treat copper concentrates. Chalcopyrite is quite refractory in leaching and in sulfate milieu an autoclave of high temperature and pressure is required. However, in the HydroCopper«-process copper sulfides can effectively be leached in atmospheric pressure using strong, aggressive chloride solution and copper (II) ions as oxidant. Copper is precipitated from the purified pregnant leach solution as copper (I) oxide, which is filtered and reduced by hydrogen gas to metallic copper powder, which is melted and cast into copper product. Sodium chloride formed in precipitation is decomposed in a chlor-alkali electrolyser, the products of which are circulated back to the process: sodium hydroxide to copper (I) oxide precipitation, chlorine gas to leaching and hydrogen gas to the reduction of copper (I) oxide. During 2003 - 2004 the performance of the HydroCopper«-process was confirmed in a demonstration plant processing one tonne of copper per day. It has been found to be applicable for different kinds of concentrates and can also tolerate a wide range of impurities. A significant advantage of the process is that gold can be leached as a chloro-complex and recovered with active carbon. HydroCopper« can economically recover copper from concentrates and process to a cast copper product. The best utilisation of the process is in most cases achieved when the plant is situated at the mine site. Higher recoveries are attained by the optimisation of the whole operation chain from the mine and the concentrator to the HydroCopper« plant.

Jan 1, 2005

The Bendigo Goldfield is AustraliaÆs second largest goldfield, having produced 22 million ounces of gold between 1851 and 1954. Development of the modern decline mine, initially for underground exploration and bulk sampling, commenced in 1998. The project is targeting new reefs below and along from historic workings beneath the city of Bendigo. The major technical challenge for the project is the inability to solely use drill core gold assays to estimate the grade of reefs, due to the coarsegrained nature of gold mineralisation, known as the nugget effect. In 2002, a program of bulk sampling commenced, resulting in the development of factors for converting drill hole grades to in situ reef grades. In mid 2006 commercial production commenced following the construction of a 600 000 t/yr processing plant adjacent to the Kangaroo Flat Mine portal, with plant feed being derived from four reefs in the Sheepshead and Deborah lines of reef. In early 2007 it became clear that the initial ore reserves had been overestimated, leading to an immediate change of strategy from production to exploration. A cash conservation program was also put in place. Exploration refocused onto the more historically productive Garden Gully and New Chum lines of reef, whilst a new grade estimation tool based primarily on the visual assessment of drill core was implemented. Immediate exploration success occurred with the discovery of four reefs in the Garden Gully line in early 2007. Successful step-out drilling during the year led to the decision to undertake trial mining in Gill reef. Trial production commenced in June 2008 and includes the processing of discrete ore blocks and the introduction of selective mining techniques. This paper examines the steps that have been taken to refocus exploration and to gain confidence in new exploration results, particularly through the visual grade estimation technique and assessment of trial mining Gill reef on the Garden Gully line. In addition, project factors relating to human skills, community relationships and financial management in a dynamic external environment are also addressed.

Jan 1, 2009

By Mack JF

A metallurgical evaluation of the Argyle Kimberlite No. 1 (AKl) orebody has been carried out using a 40 tonnes per hour pilot plant. Pilot plant results, together with laboratory investigations provided a basis for the determination of process design criteria for a major treatment plant. Various sampling programmes were carried out to determine specific aspects in the evaluation of diamond liberation. Treatment parameters such as the top crush size, recrush size and the bottom cut-off size were investigated. A description of the pilot plant is given together with the design criteria for a 3 million tonne per annum treatment plant

Jan 1, 1984

Laboratory and pilot plant investigations aimed at recovering gold as an electroformed sheet from gold eluate and gold leach solutions and slurries are discussed. The electrolytic test work undertaken makes use of high surface area electrodes, in particular nickel-chrome foam metal and activated carbon, as well as ultrasonic activation. The process involves initial gold electrowinning (or adsorption onto activated carbon), followed by gold electroforming, both operations being carried out in a specially designed reactor. The pilot plant work mainly involved the treatment of gold eluate solutions from a South African gold mine containing 600 mg/L Au: some tests were also carried out on gold leach solutions containing 6 mg/L Au. In the former case, very efficient gold extraction onto the foam metal cathode was achieved using electrolysis combined with ultrasonics. The polarity of the gold-loaded cathode was then reversed and, using a replacement electroforming electrolyte, gold was electroformed in situ onto a polished stainless steel mandrel, from which gold sheet was subsequently removed. In the case of leach solutions, pilot plant tests confirmed laboratory findings that in the presence of calcium (resulting from the lime used during the leaching process) no electrowinning is possible. Laboratory tests showed, however, that when sodium (in the form of NaOH or Na2CO3) is added to the leach solution, electrowinning can indeed take place. Alternatively, if a special activated carbon electrode is used (without current), the non-ionic calcium aurocyanide complex is adsorbed on to the activated carbon. When a gold-loaded activated carbon electrode is made anodic in a gold electroforming electrolyte, gold electroforming is feasible, although the efficiency is very low. The possible implications of these developments for gold recovery are further examined.

Jan 1, 2007

This is the second of a series of papers dealing with Geology in Exploration. The first, published by the Australasian Institute of Mining and Metallurgy, Proceedings Nos. 143-144, 1946, was written as an introduction to the subject and employed the exploration geology of the Cobar field to illustrate the prospect thinking. This paper will be concerned with the problem of ore repetition in depth and borrow its- example from the Mount Lyell copper field. The writing will be taken up altogether by the example. Nevertheless the intention remains to develop the subject in terms of its wide interest and application.The Mount Lyell field possesses large actual and prospective resources within, and in the vicinity of, the known deposits. This paper does not bear at all on these accessible ore reserves and tangible prospects. There is also in this area evidence of deep ore. The possibility is of little practical interest at present. But the picture of ore repetition, exemplified by the Mount Lyell field, does matter now to the outlook on exploration in this country. For once this essential feature of ore occurrence is widely understood there may develop, on the scale warranted, the search for major deposits which do not outcrop but which are still at shallow depths because of the part erosion plays in this story of concealment and exposure of ore. Also there is the chance in some fields (including Mount Lyell) of a second harvest of orebodies within mineable depths. This exploration goal, introduced in the first paper, will appear more clearly as the Geology in Exploration series is written up. Here the concern is to show the character of the geological evidence which points to the occurrence and recurrence of ore in the earth's crust, the picture at the foundation of this exploration scheme. There is considerable information in the Mount Lyell area of the structures...

Jan 1, 1947

By Chung S

The problems associated with equating calculated and measured properties of explosives with blast results are examined. The results from six full-scale test blasts in a limestone quarry are described. The purpose of the full-scale trial was two-fold, i) assess the role of varying aluminum levels (10% maximum) in a given explosive in terms of blasting performance, and, ii) find correlation between calculated, as well as measured properties of explosives and the resulting blasting performance. Each blast consisted of 36 holes, initiated with short period detonators in a staggered 3-row 2.4 m x 2.7 m (burden x spacing) pattern. Each 75 mm diameter borehole with no subgrade contained on the average 22 kg of 65 mm diameter cartridged explosive. The bench height was 6.3 m, with an average collpr of 1.2 m. The calculated and mgasured properties of explosive included, strength, detonation and explosion pressure, VOD, plate-dent depth, underwater bubble and shock energy, and the total energy efficiency. Each blast was instrumented to measure detonation velocity, initiation sequence, muck pile motion by means of high-speed photography and blasting vibrations. The post-blast measurements included photogrammetric survey of muck pile for size distribution on surface, muck pile profile, as well as the extent of backbreak. The results showed that the overall blasting performance of the explosive in question was nearly commensurate with the level of aluminum in the explosive, and there was excellent correlation between the underwater test properties and the blast results. The study also exemplified the need for more extensive post-blast analysis than is usual practice, for quantitative assessment of blasting performance of explosives and providing the necessary data-base for calibration of blasting models.

Jan 1, 1990

The sharp deterioration in Au~tralia'S ternn of trade in recent years and the accumulating national debt highlight the need for a restructuring of the economy which is highly dependent upon primary agricultural and mineral commodity exports (figure 1). Table I gives an indication of the value that can be added to raw material by mineral processing. Significantly higher value is added through downstream manufacturing. In 1987, the mining and rural sectors accounted for 47010 and 38010 respectively of total exports valued at $35,782 million (figure 2). The export contribution from minerals comprised $12,266 mil- lion from unprocessed ores and concentrates and $4,668 million from metals and processed minerals including some simple manufactures. Coal accounted for 450/s of total primary mineral exports. Iron ore and alumina are other important mineral exports, while gold and aluminium are major metal exports. (Figure 3) Australia's minerals are now traded in a much more competi- tive and oversupplied market in contrast to the 1960's and 1970's period which was characterised by increasing exports of largely unprocessed ores and concentrates. Since the early 1980's (I cI) resscd )ver~cas nutrkcts and km rununodlity liriccs ha~c hcen the product of excess capacity installed to satisfy a forecast high growth in demand which never eventuated due to the world reces- sion. During this period the emphasis on technology development was focussed on reducing costs through increased production effi- ciencies in order to maintain competitiveness.

Jan 1, 1988

The sulphide ore occurring in the North Mine at Broken Hill is of a complex nature, consisting of an intimate mixture of argentiferous galena, marmatite (zinc-iron sulphide), and gangue minerals. A typical analysis of the ore is:Lead 15.2%Zinc 12.0%Iron 5.3%Manganese 0.8%Copper 0.1%Alumina 0.3%Lime 0.9%Sulphur 11.1%Insoluble 53.8%Carbon dioxide 0.3%Undetermined 0.2%Silver 9 oz. per tonTotal 100.0%The metallurgical practice for the recovery of the lead concentrate and zinc concentrate from the crude ore is briefly described in the following pages.(1) COARSE CRUSHING AND FINE GRINDING OF THE CRUDE OREThe crude ore from the mine, containing lumps to the size of, roughly, 10 in. x 8 in., is tipped over grizzlies with the bars spaced 3 in. apart; the oversize gravitating to a...

Jan 1, 1933

By Forster G, Datta P. K

Many high temperature industrial processes involve gaseous halogen-bearing environments. Essentially, these fall into three subject areas: power generation, waste incineration and especially extractive metallurgy. Fundamental to any understanding of the process chemistry and efficiency in the process technology is an adequate knowledge of background thermodynamics relating to metal-chlorine reactions. In this context, existing free energy/temperature diagrams for metal chlorides do not include many elements, in particular the so called refractory elements from Group V and Group VI of the Periodic Table, namely niobium, tantalum and vanadium, and molybdenum. This paper reports estimation and calculations of the free energy values for these chlorides. The data is discussed in the context of high temperature chlorination processes.

Jan 1, 1991

By R Peden

Recent, detailed mapping, (Allibone, 1986; Peden, in prep.) of north west Stewart Island, has shown that the Rakeahua Granite (Watters et al, 1968), is comprised of a wide range of granitoid bodies ranging from diorite to leucogranite. As a result of the wide variation in granitoids Allibone (1986), suggests renaming of the Rakeahua Granite to the Rakeahua Granitoid Complex. Names were also proposed for the individual granitoid bodies mapped.

Jan 1, 1987

By L Lagoeiro

The samples studied in this paper were derived from the iron oxide facies of iron formations (IFs) of the Quadrilßtero Ferrffero, south-eastern Brazil. The rich-iron oxide varieties of the IFs can be regarded as Fe-O systems because they consist predominantly of aggregates of haematite and magnetite crystals. The study was based on carefully selected samples in which magnetite crystals occur as isolated large crystals set in a matrix of haematite grains. Optical microscopy and an electron microscope equipped with an electron backscattered diffraction (EBSD) system were used to investigate the microstructural and crystallographic relationships involved in the phase transformation between magnetite and haematite. The magnetite crystals in the IF samples are partially transformed to haematite and this process is also known as martitisation. This transformation occurs along the crystallographic planes {111} of the magnetite producing a characteristic triangular pattern of interlocking lamellae of transformed haematite crystals that are oriented parallel to octahedral plane {111}. This new generation of haematite is referred to martite because of the martitisation process. EBSD analyses show that the magnetite and the new haematite crystals, martite, share crystallographic planes of highest atomic density, eg {111} and (0001), respectively, possibly due to the ccp and hcp atomic arrangement of the two crystals. Stereographic projections of these two planes therefore coincide when the maxima of their poles are plotted. However, the crystallographic orientation of the haematite crystals in the matrix shows maxima of (0001) poles that do not coincide with those of {111} planes of magnetite. Consequently, it is concluded that the direct transformation to haematite crystals retains the crystallographic orientation memory of the former magnetite crystals, possibly due to the similar manner whereby their atoms are packed together in the crystal structures. On the other hand, no such relationships are observed between magnetite and haematite crystal in matrix. This suggests that haematite grains in the matrix may have been formed by other processes rather than those involved in the iron oxide transformation observed within the magnetite grains.

Jan 1, 2008

By Menne D. M, Ladyman R

Camel Creek Mine operated by Lynch Mining Pty Ltd is located 65 km west of inghain and 160 kin north west of Townsville in North Queensland. (Figure 1). The Camel Creek gold mineralisation was discovered in mid-1987 in an area previously known for its tin workings. Mining commenced in January 1989 after an oxide reserve of 1.2 million tonnes @ 2.1 g/t gold had been delineated. The first gold pour was in May 1989. The mine developed into a medium sized open cut operation, with full site facilities. The initial mining rate was 500 000 tpa utilising run-of-mine (ROM) heap leaching to recover the gold. By the end of 1990 the wider orehodies were mined and efforts were focused on the narrow orebodies, of width typically less than three metres. Smaller earth moving equipment was employed to selectively mine the narrow orehodies leading to a decrease in the mining rate to 200 000 tpa. The Red Gold deposit (80 000 tonnes « 3.0 g/t to 18 in vertical) was mined in mid-1990 and ore was hauled approximately 8 kin to the Camel Creek heap leach operation. The ore was hauled in a dedicated campaign after being stockpiled. The cost of dedicated ore haulage ensured that only the more exceptional of the remote orebodies could be mined in this manner. The Golden Cup orebody, some 20 km from Camel Creek, was too distant to permit ore haulage. However, this prospect contained sufficient gold (initially 90 000 tonnes @ 3.0 g/t) to warrant the installation of a small mobile adsorption facility. Construction of the second heap leach operation commenced in late-1990. Gold production commenced in early April 1991. Mining of several smaller orebodies remote to the second heap leach facility has been undertaken and further mining is planned. This paper outlines heap leaching practice at Camel Creek Mine and summarises the success of the Golden Cup heap leach.

Jan 1, 1994

The mineral industry is an important element in the human environment and in varying degrees contributes to the general standard of living throughout most of the world, both by supplying the basic materials required for heavy industry, transportation, construction, scientific equipment, and many labour saving tools and also by its contribution to the international economy.When projecting population growth and per capita resource utilization against a finite amount of nonrenewable mineral resources, it is apparent that at some future time, if the established trend continues, the supply of industrial minerals will progressively become exhausted according to their relative scarcity and world demand.In one way or another all of nature's mineral resources are used in the sel'vice of man. Some of the products of their manufacture are essential to the survival and further development of our civilization, others are luxuries, desirable but not essential. Marine vessels are essential to maintain a flow of resollrces around the world, and as trade increases the size of the fleet will grow and the quantities of metals needed will be greater.The commodities they transport, may be used in an inefficient or extravagant manner causing unnecessary depletion which may adversely affect the activities of future generations. An example that comes readily to mind is fuel oil, the international transport of which uses a vast tanker fleet. When refined, large quantities of motor spirit are used in motor vehicles. The U.S.A. alone uses 70 billion gallons annually in the 90,000,000 automobiles in use.Much of this is used in private cars-of which there is one for every 2'3 people-for transport between home and city. Well organized community transport would serve the same purpose, conserve a scarce commodity, take some of the stress out of livingdriving in a major city can hardly be considered a relaxing experience-and minimize the problem of atmospheric pollution.Whilst man has demonstrated his great versatility...

Jan 1, 1973

Coal washing practice can be improved not only by critical examination of the plant being operated but also by studying plants operated in other areas. The developments at the Australian Iron & Steel Pty. Ltd. plants are discussed in relation to experiences there as well as developments which have taken place in Queensland in recent years. Early A.I.S. problems involved small coal cleaning in heavy medium cyclones and flotation. A proposed future plant flowsheet for A.I.S. is considered in the light of these experiences. Reference is made to plants operated by the Thiess, Peabody, Mitsui Coal Company Pty. Ltd. at Moura and the Utah Development Company's plants at Blackwater and Goonyella in the development of coal washing prac- tice in Australia.

Jan 1, 1975