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By Morland R

In the course of an exploration program aimed at increasing Pasminco Mining's ore reserves, an electromagnetic survey down one of the underground drillholes at the North Mine, Broken Hill, recorded a broad and persistent response. This paper demonstrates that the anomaly was not due to any geological feature, but rather was caused by 'self-response' of the sensing probe. The observed results are due to the surveyed hole lying within a resistive environment and having distinct, but not unusual, changes in dip.This phenomenon has not been widely reported and we believe that there are likely to be similar cases in company records where very genuine looking responses are due to self-response rather than sulphides. These false anomalies can be recognised by correlating the observed data with the calculated down-hole component of the transmitting loop's primary field.

Jan 1, 1994

The Quiruvilca district, located 80 km east of Trujillo in north central Peru (Fig. 1), has produced over eight million tons of Cu-Pb- Zn-Ag ore from approximately 60 veins since 1789. "Quiruvilca means "sacred tooth" in Quechua, the lingua franca of the Incas. The expression refers to a prominent volcanic neck exposed several kilometers northeast of the district. The district covers an area of approx- imately 24 km2. The mines occupy the eastern quarter; workings underlie 6.7 km2 with a developed vertical range of 280 m. All pres- ently operating workings are owned by Corpora- cion Minera Nor Peru S.A., a subsidiary of ASARCO Incorporated. The oldest rocks in the area are Lower Cretaceous clastic sedimentary rocks exposed 7 km to the east. Lithologies include sand- stone, siltstone, shale, coal seams, and carbonates (Cossio, 1964). These rocks were folded and affected by regional low-grade metamorphism during the early Tertiary, 40-65 m.y. (Hollister, 1977).

Jan 1, 1987

The economic viability of many Southern African massive mining operations is threatened by excessive dilution. In many operations currently in progress, some stopes are experiencing as much as 115 per cent waste ingress reporting to drawpoints. This paper examines the magnitude, causes and types of dilution and presents a set of general principles for the control of dilution in massive stoping operations.

Jan 1, 2000

By Kurzeme M, Willoughby D. R

Current research at the CSIRO, Division of Applied Geomechanics, into the mode of response of fill as a structural component has been based on model tests for prediction of behaviour and field observation of critical parameters. The procedure is summarised in four stages: (a) define the specific fill function (b) postulate the mode of failure (c) use models to quantify the conditions (d) monitor critical parameters to check or update the analysis in (c). The above procedure is used to postulate the failure modes of each of the possible func- tions performed by fill materials. Analytical techniques, or lines of investigation, are described for each of these modes and specific reference is made, where, possible, to an exis- ting mine environment.

Jan 1, 1973

I WISH to express to the members of the Institute my sincere appreciation of the distinction which they have conferred upon me by again making me their president. It also gives me great pleasure to once more welcome the Institute to Mount Lyell.Since your last visit certain improvements in plant have been made, which I trust you will have found interesting, and which show that, though located in a remote corner of the world, we are abreast of the times.The opportunities which a recent lengthy trip to America has given me to observe the degree of interest which our local smelting practice continues to arouse in metallurgical circles make it seem appropriate that I should take advantage of your visit to lay before you some detailed information on the more practical features of pyrite smelting, particularly as carried out at Mount Lyell. There are only a few places in the world where the method is now being practised in approximate purity-only about half...

Jan 1, 1915

By Kobe HW, Balance PF, Black PM, Sporli KB, Smith IEM, Locke CA

The Hauraki Goldfield consists of a large number of volcanic-associated epithermal gold deposits within the Coromandel Volcanic Zone (CVZ), North Island , New Zealand; it is the most accessible and most studied of the Southwest Pacific gold regions. The deposits occur generally as steeply dipping quartz veins and breccia sheets in faults and fractures.From a tectonic perspective, the CVZ is generally considered a Neogene convergent volcanic arc constructed under an extensional tectonic regime; the common tectonic setting for epithermal mineralisation. The gold deposits are mostly hosted in subaerial andesitic arc-type volcanic rocks. Temporally, however, mineralisation is associated with rhyolitic rocks of a bimodal volcanic suite that may represent a back-arc environment. Rifting and calderas may be important components of the latter regime, but this is not yet clear; the general structural framework controlling the location of CVZ gold deposits remains poorly understood. Geophysics, particularly aeromagnetics, has a role in mapping regional fault patterns in the CVZ

Jan 1, 1990

At Hilton Mine, 18 kilometres north of Mount Isa, the silver-lead-zinc sulphide bodies have undergone strong deformation in the form of folding and later faulting and brecciation in the hangingwall region of the mine. Variation in grades and widths over compara- tively short distances causes problems regarding accurate sampling of orebody exposures in underground development, and in defining confidence limits for the extrapolation of ore intersections in ore reserve calculations. The paper gives a preliminary insight into the problem of obtaining representative samples for exposed orebodies and discusses the sampling techniques employed. Results gained from these sampling methods could not be verified due to lack of individual bulk samples for comparison but strong evidence for precision was provided. INTRODUCTION In a developing mine like Hilton, accurate grade information is of extreme importance. Original grade information for a potentially viable ore deposit is gained from surface drilling, and initial ore estimates are calculated from the resultant ore widths and grades. After underground development has proceeded, the opportunity arises for detailed examination of orebody exposures, and the resultant assay grades and widths from sampling of these exposures may, in the long term,

Jan 1, 1976

By Yinxiang W, Chunlai Y

In older to improve efficiency of surface pre--grouting in sealing off water in heavily water-bearing strata, such as sandstone,siltstone and limestone, several methods have been used in China, they are ; intermittent pre-grouting, adjusting pre-grouting parameters and stepwise repeated pre-grouting methods. The paper describes effect of deviation on water sealing in pre-grouting. Deviation correction measures, like mechanical, technological and changing hole position methods have been introduced with satisfactory results in practical engineering projects without increasing the volume of engineering project and without causing delay.

Jan 1, 1988

An improved technique for the quick and accurate measurement of the weight and centre of mass in the horizontal plane of large machines has been developed. On-site weighing of large plant such as bucket wheel dredgers is an important part of the commissioning procedure. The results from the weighing assist in determining the stability of the machine and also enable confirmation of the structural weight distribution used for stress analysis at the design stage. In this paper the techniques previously used for weighing are reviewed and the sources of error using these methods examined. A full descrip- tion of the current technique and procedure is given explaining how the measurement system comprising strain gauge load cells, displacement transducers, wind speed and direction sensors, data logger, computer and software was developed to enable quick and accurate measurements to be made. Proposed modifications to software necessitated by the replace- ment of current measuring instrumentation and computer are discussed. A typical example of measurements from the weighing of a large dredger, illustrating the accuracy of the new technique is given and the calibration technique used to check the accuracy of the force and moment measurements is explained. An outline of how the results are used to certify the machine for operation is given.

Jan 1, 1989

The Barra Mine was the most significant mine of Australia's earliest mining era, which took place in South Australia between 1841 and 1851, the decade prior to discovery of gold in eastern Australia. Between 1845 and 1860, Barra was the largest metalliferous mine in Australia and employed up to 1000 men and boys, most of them Cornish.""Today the site is also important in a physical and archaeological sense as it contains extensive remains of mining and processing operations of the period 1850 - 70. Most significant are three cnginchouses which housed Cornish beam engines.

Jan 1, 1993

By C A Heinrich, Morse M. P, Cruickshank B. I, Pyke J. G, Whitaker A

Very little public domain information is available on the exploration signature of the Coronation Hill Au+Pd+Pt deposit. From 1987 to 1990 the BMR (now AGSO) carried out geological, geophysical and geochemical (whole-rock, stream, soil and rock chip) surveys within the South Alligator and Kakadu Conservation Zones and defined several key parameters useful for exploration programs. The essential geological ingredients for the style of Coronation Hill Au+Pd+Pt¦U deposit are oxidised, low pH fluids, dilatant fault structures, a thick neutral to oxidised cover sequence and chemical traps in the basement. In geophysical data, the areas surrounding the mineralisation can be detected by airborne magnetics as major lows in magnetite-rich rocks, whereas in airborne gamma-ray spectrometry data, imaged spectrometric channel ratios such as U2/I'h and U2/K highlighted alteration surrounding the deposits. Three types of stream-sediment and soil samples were taken from each site: (1) -1 mm mesh, 5 kg sample for bulk cyanide leach (BCL) analysis for Au, Pd, and Pt; (2) 1 kg sample of -1 mm mesh sediment for fire assay/ICPMS analysis for Au, Pt and Pd; and (3) 50 g - 180¦ mesh sample for a variety of trace element analyses, including Au, Pd and Pt. Techniques 2 and 3 gave similar results for Au, Pt and Pd, while the recovery rates for Pd and Pt from the BCL samples were considerably lower. Other trace elements did not define unique indicators for Pt or Pd mineralisation, as each sample reflected the dominant lithology in the drainage basin. Rock chip surveys were useful in determining which faults were associated with the ore fluid in regions of multiple fracturing. Results from these exploration-style surveys also confirmed that the Coronation Hill deposit is a variant of the unconformity-style of mineralisation, as all significant geochemical and/or geophysical results occur at or below the unconformity.

Jan 1, 1994

By D Duan

In this study, aimed at two kinds of ore (lump ore and iron ore fines) and four types of Australian iron ore resources (haematite iron ore, Mara Mamba iron ore, limonite iron ore, and mixed iron ore, such as Newman, MAC, Yandi and Pilbara iron ore), the physical and chemical properties and high-temperature properties were investigated in detail, to master their behaviour and effects in sintering, blast furnace, and non-blast furnace processes. Then, according to the individual properties of Australian iron ores, Chinese domestic iron ores and Brazilian iron ores, etc, the optimisation of ore-proportioning for sintering, blast furnace, and non-blast furnace processes was studied based on the interaction of the individual iron ores and their complementary properties, and the corresponding tests were carried out. The test work results indicated that this method not only improved the technical and economic indexes of sintering, blast furnace, and non-blast furnace processes, but also increased the addition of Australian iron ore. All of these provide the theoretical basis and technical support for highly effective use of Australian iron ore resources in iron and steel enterprises in China.

Jul 11, 2011

By Harvey T, Kizil M, Bride J

Hydrogen sulphide (H2S) as a seam gas has occurred in several locations in the German Creek seam at Southern Colliery. This paper overviews the techniques developed to quantify the H2S content of the seam, overviews research into controlling and reducing H2S emissions from the seam, and details the procedures used to mine through the HZS zone in 702 longwall panel. Learning points from research and mining experience are reviewed for application in the next longwall block.

Jan 1, 1998

By BTrubT M

In the roast-leach-electrolysis process for the production of zinc, iron contained in zinc concentrates is converted to zinc ferrite during roasting. At Canadian Electrolytic Zinc (CEZinc), the Outokumpu Conversion process is used to simultaneously leach zinc ferrite and precipitate the iron as jarosite. These simultaneous reactions, while providing good process stability, require a compromise between optimum conditions for maximum zinc extraction and efficient iron precipitation. An improved conversion process has been identified which can achieve >99 per cent zinc extraction and more efficient jarosite precipitation to residual iron concentrations of

Jan 1, 1993

By B Davis, M Wallace, J Stewart, C F Burrett, J B. Cannell

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Sepon district in Lao PDR contains 1.8 Mt of JORC (2012) compliant contained Cu resources in addition to >4.5 Moz of Carlin-like Au in a Palaeozoic sedimentary package. The Cu deposits are proximal to an EW lineament of Permian rhyodacite porphyry (RDP) intrusive centres that are characterised by intense barren quartz stockworks. The Khanong deposit (42 Mt at 3.0 per cent Cu mineral inventory) is a carbonate replacement intermediate sulfidation deposit verging on a high sulfidation environment, where abundant pyrite, copper sulfides (chalcopyrite, bornite, trace enargite), copper sulfosalts (including tennantite – tetrahedrite, colusite), and base metal sulfides (sphalerite and galena) have replaced low dipping dolomite and limestone layers, forming a manto-style orebody fed by steep dipping intensely silica-pyrite altered structures. The Thengkham deposits (54 Mt at 1.5 per cent Cu) are composed of prograde skarns (garnet, clinopyroxene) and mineralised retrograde skarns (chlorite, magnetite, hematite, epidote, sericite, talc, serpentine, carbonates, sulfides) which are irregularly and semi-continuously distributed around an elongate 4 km long intrusive centre. Thengkham and Khanong have been strongly supergene enriched, forming secondary chalcocite breccias and exotic malachite zones.The Carlin-like Au deposits display a range of stratigraphic and structural controls and lie outboard of the Cu deposits. Similar structural controls, alteration assemblages and trace mineralogies suggest that gold and copper mineralisation are temporally and genetically related. It is hypothesised that the differences in style of Cu and Au deposits across the Sepon district are related primarily to palaeodepth and proximity to the intrusive centres.CITATION:Cannell, J B, Stewart, J, Williams, P, Wallace, M, Burrett, C F and Davis, B, 2015. The Sepon copper deposits (Laos) and their relation to Carlin-like gold mineralisation, in Proceedings PACRIM 2015 Congress, pp 399–408 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By L Neindorf

The development and application of paste fill, cement slurry aggregate fill and shotcrete bulkheads at Mount Isa Mines is described. The progressive changes in filling style in the Mount Isa copper mines from a dry fill based cemented rock fill to tailings based paste fill and slurry fills is explained. The development of shotcrete arched bulkheads and engineered drainage system is described. Details on how Mount Isa Mines has achieved approximately 30 per cent cost reduction in backfill operations through innovations are given. The development of a rocky paste fill is explained.

Jan 1, 2005

By Reed M. E, Cloutt B

Particulate samples were taken from the gas space in the settler of the Kalgoorlie nickel smelter using a vertical sampling probe and a specially designed isokinetic sampling probe which also quenched the samples. The vertical sampler was found to give unrepresentative samples. Suction thermocouple measurements of the gas temperature were also made. Using the isokinetic probe samples were taken at four points ranging from near the base of the reaction shaft to the base of the uptake at depths up to 1.5 m into the settler. Dust loadings and the sizing of the samples were determined. These parameters were found to be most affected by sample position and depth. The dust loading decreased along the settler but increased with depth. The loadings varied from zero near the roof to several hundred g Nm 3 near the slag. The dust also became coarser with increasing depth into the settler. Examination of the samples showed them to consist of spherical particles the largest of which were about 500 microns in diameter. The dust was mainly composed of mixed iron/nickel oxides with a little sulphide.

Jan 1, 1991

By J Skousen, C E. Zipper

"Prior to the 1950s in the USA, surface coalmines were generally left without any reclamation. As government regulations advanced, mine operators were required to backfill the area and plant grasses or trees. After the federal Surface Mining Control and Reclamation Act (SMCRA) was passed in 1977 in the USA, mine operators were required to conduct pre-mining analyses of the site and to designate a land use that could be achieved after the mining. Common post-mining land uses in the USA are: agricultural uses such as prime farmland reclamation with crops, hayland and pasture, and biofuel crops forestry wildlife habitat building site development.Provisions and regulations for each post-mining land use were developed and practices to achieve successful and sustainable land uses were established. Post-mining conditions should provide ecosystem services and produce lands capable of supporting societal needs in the future.CITATION:Skousen, J and Zipper, C?E,?2014. Post-mining land use options in the Appalachian coal mining region of the USA, in Proceedings Life-of-Mine 2014, pp 153–164 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 16, 2014

By Y Peng, D J. Bradshaw, G Long

As copper reserves deepen, they are becoming increasingly less pure. Penalty elements such as arsenic, antimony and bismuth are occurring in increasing concentrations. Environmental issues with smelters are leading to increases in penalty rates for these elements such that some concentrates may become difficult to sell. Arsenic concentration in Rosebery copper concentrates during 2010 varied between 3000 and 8500 ppm. Arsenic levels above 5000 ppm can preclude import to some customer countries. Optical mineralogy has indicated that arsenic in Rosebery copper concentrates is most commonly associated with tennantite (Cu12As4S13) in solid solution with tetrahedrite (Cu12As4S13). In addition, silver reports to concentrate as freibergite (Cu12As4S13 ). A reduction in arsenic content will therefore lead to a concurrent reduction in the silver content.A literature review by Long, Peng and Bradshaw (2012) indicated that arsenic bearing minerals could be removed using potential controlled flotation. Some success in reducing the amount of arsenic had also been reported using either roasting or chemical depression using reagents such as lime and cyanide. Due to the location of the Rosebery concentrator adjacent to world heritage listed temperate rainforest, the use of a roaster or cyanide was immediately discounted. Lime is already used as a reagent in the Rosebery flow sheet, so could be considered as a potential arsenic depressant.In order to determine a method of separating out the high arsenic bearing minerals, two series of flotation tests were conducted. The first series investigated the effect of pulp potential on the recovery of copper, silver and arsenic minerals; a second series investigated the effect of pH, froth depth and regrind.CITATION:Long, G, Peng, Y and Bradshaw, D J, 2012. Production of a low arsenic copper concentrate at MMG Rosebery, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 347-354 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

Ore sorting is a high capacity, low cost method of preconcentrating ores and in some cases of producing a marketable concentrate. In most cases it is applied to run of mine material, immediately after primary crushing and screening in sizes ranging from 10 mm to 150 mm. Recent developments in bulk sorting of friable uranium deposits have resulted in machines capable of handling fine materials with sensing and separation being achieved on a zone by zone basis. Modern ore sorting machines rely on the synchronous operation of four internal sub systems, feed presentation, sensing, data processing and separation. A variety of different sub systems is available which can be combined in various forms to produce sorters capable of handling a wide variety of mineral types. The benefits in using ore sorting cover a wide range of situations and are applicable to both established mines as well as new mining ventures. Reduced operating costs, increased productivity, capital savings, energy and resource conservation and environmental issues are all part of the reason why ore sorting is finding rapid acceptance in today's mining industry.

Jan 1, 1980