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Deposits of manganese oxides and silicates in the Tamworth area were re-examined. The major deposit at Danglemah consists chiefly of rhodonite and the rare silicate tephroite. It is considered that the manganese was deposited with the original sediments, the silicates being formed later during the intense folding and low-grade metamorphism of the enclosing rocks.INTRODUCTIONMany small deposits of manganese oxides and silicates occur along a belt of eastern New South Wales and Queensland.Some fifty occurrences, most of which have been subject to mining activity, were described by Lloyd (1943) and some of this information was summarized by Knight (1947). The ores have been mined on a small scale since 1884. Small supplies of battery grade ore were won from a number of deposits, while larger quantities of metallurgical grade were sold to the steel industry. Maximum production was in 1918, when 6,500 tons were mined.The siliceous nature of many of the ores and their occurrence in the neighbourhood of granite batholiths led earlier investigators to consider the deposits to be of hydrothermal origin, associated with the granite intrusions. The present work questions this viewpoint.In this investigation, three of the chief deposits in the Tamworth area were seen. These were at Danglemah, which is being mined at present, and Mount Jasper and Manganese Mountain, which were mined in the past. The Danglemah mine is the most accessible and yields the best material...

Jan 1, 1962

By Ryan CG, Ramsden AR, Sie SH, French DH, Griffin WL

Proton microprobe and electron microprobe analysis are being used in combination for in situ determination of the trace element contents of oxide, sulphide and silicate minerals in a sample of the Merensky Reef. Initial results indicate that chromites contain only Ni, Zn, Ga, Zr ar d Nb. Platinum-group elements, if present, are at concentrations less than 2 to 6ppm. Ru, Rh and Pd are the only platinum group elements to be consistently detected in the sulphides. PentLindite is the most important host for these elements with the concentration of these elements being dependant upon the mineral association in which it occurs

Jan 1, 1989

By C Rogers

"The Coal Seam Gas (CSG) industry has seen a rapid increase in activity over a 30-year periodfrom the early 1990s within Australia. Despite public concerns over environmental issues, theCSG industry has increased in Queensland to the point where more than 90 per cent of naturalgas consumed in Queensland is CSG. The New South Wales (NSW) CSG industry has been slowerto respond for many reasons. Ninety-five per cent of natural gas consumed in NSW comes frominterstate. However, CSG activity in New South Wales is increasing notwithstanding publicconcerns. The CSG potential of three Petroleum Exploration Licenses (PELs) are being assessedwithin the Southern Sydney Basin that provides a unique opportunity to develop resourcesstrategically around many abandoned coal mines. The question has been asked - what do theseabandoned coal mines mean to the project? Are they good or bad? Are they friend or foe? Thispaper att empts to answer these questions and in doing so describes the coal mine ventilation andgas management philosophies and practices used to assess gas production potential. The coalmining philosophies not only have the potential to assist in the construction of a highly successfulCSG project, but they also potentially add signifi cant pre production value by re defi ning how theresources and reserves are assessed and therefore valued. The behaviour of abandoned coal minesand the goaves within the PELs are not well understood by the petroleum industry. However, in the Illawarra region there is an abundance of coal mining knowledge and expertise that if properly focused can greatly increase the chances of project success."

Jun 1, 2012

By Olden WH

A scheme is presented whereby the complexities of design and operation of a hydraulically powered coalmine support are modelled using the finite element method. This enables predictions to be made of the interaction of the support with its environment in a variety of operating conditions. The model is a two dimensional representation. The modelling scheme was applied in two case studies. In the first, the performance of a four leg support was uprated by increasing the front leg force. The finite element model enabled changes in overall support performance to be verified. In the second case study, the change in lateral force developed by a two leg support was assessed with changes in support operating height and floor foundation stiffness. The modelling scheme is capable of further development with the possibility of extending the model into three dimensions and the addition of control elements that would enable an actual mining sequence to be Represented.

Jan 1, 1992

Interest in the sampling of refined copper cathodes has heightened over the last ten years. This has followed the increasing importance of cathodes as the principle trading form for metallic copper. It has also been given impetus by recent trends for quality certification of manufacturing inputs, specifically the AS3900 and IS09000 series of standards.

Jan 1, 1976

By K Voigt, B Bolton, C Rumble

The Ok Tedi copper and gold mine is owned and operated by Ok Tedi Mining Limited (OTML) and is located in the Star Mountains of the Western Province of Papua New Guinea. Waste materials (both sulfidic and carbonate materials) from mining operations, comprising 55 Mt of waste rock and 31 Mt of tailings per annum, are discharged into the headwaters of mine area creeks where erosion and sediment transport carries significant proportions of the total waste into the Ok Tedi and Fly River systems. The tailings are potentially acid forming (PAF) while the waste rock has been strongly acid consuming with an excess of acid neutralising capacity (ANC) due to the high proportion of limestone waste. Tailings and waste rock are eroded into the river system and transported to the lower Ok Tedi and floodplains where deposition takes place. Because of concern due to vegetation die back, a dredging operation commenced in March 1998 to remove the sand fraction from the main river channel. OTML identified a potential future ARD risk from the stockpiled sands due to reduce limestone production at the mine and sulfide/carbonate mineral segregation in the river system and in the dredge sand stockpiles. This paper describes the structure and framework of an empirical model developed to assist OTML in planning ongoing mining operations to control ARD. Modelling identified the need to provide additional mined limestone to prevent future ARD generation from material deposited in the mine area creeks. With the additional limestone, the ARD risk in waste rock storage areas and in the Ok Tedi and Fly River sediments is predicted to remain low due to the combined effects of high ANC, high alkalinity of natural waters and high moisture contents (mostly fully water saturated). However, monitoring and modelling indicate that the ARD risk from the stockpiled sands will increase substantially during the remaining years of the operation. OTML have initiated programs to identify and evaluate options to mitigate this risk.

Jan 1, 2003

By Ormsby W, Peters M, Van Gils H, Kehprens P, De Boorder H

The northern margin of the Arunta Block is characterized by a metasedimentary and volcanic sequence of lower metamorphic grade than that of the central Arunta Block. Whereas the Harts Ranges have granulite to amphibolite metamor- phic grades, the northern margin only reached greenschist to lower amphibolite facies. Most of the high grade area of the central Arunta Block appears to be unprospective, but the lower grade marginal fringe contains most mineral pros- pects to name a few: Barrow Creek, Molyhill and the Jervois Mine. Numerous smaller prospects occur in this marginal zone. Four major lithostratigraphic units can be recognized in the Jervois Mine area: 1. Gneissic Suite consisting of granitic and rhyolitic gneisses which are characterized by a distinct intersection lineation. 2. Metasedimentary Suite of cordierite- biotite schists and chlorite-biotite schists. 3. Mine Sequence, consisting of spotted schists with andalusite and cordierite, quartz- sericite-feldspar schists with distinct rhyo- litic remnants and quartz-sericite-feldspar schists which contain the lode horizons:

Jan 1, 1984

By Qixiang Y

The strength of coal mass saturated with gas is an essential parameter in studying the mechanism of gas and coal outburst,and its prediction method. Up to now, there has not been a method for determining the strength of coal mass saturated with gas.This paper describes a new method whereby the strength of in-situ coal mass can be determined and stored continuously and automatically. The simulation results obtained in the laboratory indicate that the new method allows a fast, reliable, inexpensive and convenient determination of the strength of coal mass.

Jan 1, 1992

By J Mavrogenes, C J. Spandler, S M. Eggins, K Worden

Major occurrences of platinum group minerals (PGM) are in crustally-contaminated, huge, layered igneous complexes (Bushveld and Stillwater) and gabbroic intrusions (Norilsk); relatively minor occurrences include arc-related æzoned Alaskan ultramaficsÆ. In terms of arc-related provenances, the recognition of alluvial PGM in river and beach deposits of southern South Island (Mitchell, 1995), in situ in the Longwoods (Cowden et al, 1990), and the ultramafic-mafic layered Greenhills Complex at Bluff (Spandler et al, 2000) raise the possibility that some economically-significant PGM deposits may exist in New Zealand. The Longwoods and Greenhills are in the Brook Street Terrane which is a remnant of a primitive intra-oceanic arc system of Late Permian-Early Triassic age. The Terrane comprises volcanogenic sequences containing plagioclase- and clinopyroxenephyric basalts, high-MgO ankaramite and dolerite dikes, trondhjemite plutons, and basaltic to andesitic volcaniclastic and sedimentary rocks. The cumulate complexes contain early-formed olivine- and clinopyroxene-rich ultramafic cumulates overlain by anorthite and hornblende-bearing gabbros. Primary (isoferroplatinum) and secondary (sperrylite) platinum group minerals are preserved in chrome-rich spinel pods in basal dunite of the Greenhills Complex. Saturation during early fractionation of primitive high-MgO magmas rather than magma mixing seems likely for the primary PGM. Together with correlative terranes in Queensland and New Caledonia, the Brooks Street Terrane is an exposed cross-section of an extensive Permo-Triassic island-arc system. Most parental magmas were primitive island-arc tholeiites, but other primary magma-types include high-MgO ankaramites and trondhjemites û the latter formed by partial melting of lower crustal clinopyroxene-rich cumulates and gabbros, respectively. The parental ankaramites fractionated to form mafic-ultramafic cumulates and primitive to evolved melts of high-Al basalt to andesite compositions (Takitimus). The Brook Street Terrane is an analogue for modern intra-oceanic islandarc systems and allows detailed study of subvolcanic arc processes.

Jan 1, 2005

By M Devia, J Rapkoch

This paper is intended to help design engineers, operating staff and plant managers understand the principles of metallurgical gas handling systems design. It also explains operating, safety and energy savings issues that the designer should take into consideration in the design of process off-gas systems for sulfide smelters. Primary smelting reactors, converters, and other off-gas sources impose challenging duty requirements on the various components of the gas handling systems. This paper reviews the design of common system components including the hood for gas capture at the system inlet, gas conditioning, gas cleaning, ductwork, dampers, hot gas fans, and the appropriate use of instrumentation and controls. The engineer must also be aware of how ductwork system effects and heat losses influence system performance. Also, the analysis of a recently-designed gas handling system will be reviewed, which includes high-strength SO2 gas from a smelting reactor, asymmetrically located Peirce-Smith converters, and a gas mixing chamber to mix the gases before they are sent to two acid plants of different sizes.

Jan 1, 2005

By P Trotta

The paper provides a structured methodology to investigate metallurgical problems within the operating concentrators. The strategy uses classical metallurgical data analysis as well as pulp, solution and surface analysis to determine the reasons for particular behaviours. The approach applies equally to all mineral-processing operations. To demonstrate its effectiveness a case study, based on work conducted at Pasminco Rosebery Mine, is described. In this work, the classical metallurgical analysis indicated that a significant amount of sphalerite reporting to the lead concentrate occurred as liberated particles. A combination of pulp, solution and surface analysis supported the hypothesis that the liberated sphalerite was recovered by inadvertent activation by lead ions. Laboratory studies have indicated that the use of sodium carbonate, by itself and in combination with zinc sulphate and sodium cyanide, when added to the lead regrinding mill can depress sphalerite flotation, resulting in an improvement in the lead grade/recovery curve. When this approach was tested in the plant other more dominant issues masked any positive effect the addition of sodium carbonate may have had. The plant trial highlighted the real need for additional regrinding capacity.

Jan 1, 2002

Pyrrhotite is pyrophoric when in a finely divided form. The problems of disposing of large quantities of finely divided pyrrhotite separated out by metallurgical processing from ore are formidable. In the case of an underground mine, a solution to the problem of disposal is to place the pyrrhotite in the stoped out areas and seal from any air supply. Further, the pyrrhotite could be diluted with tailings which would reduce the possibility of combust- ion. Several enquiries to various centres and authorities have shown that the products of the slow oxidation of pyrrhotite with moisture present can cement an inert matrix into a stable fill similar in physical prop- erties to fill stabilised with Portland cement. Stabilised fill can be used to advan tage with a suitable mining method to provide high recovery. The investigation demonstrated that air and 15% w/w water must be present for the fill to harden and that the sizing of the particles is a critical factor in drainage of a hydraul- ically placed fill and subsequent even harden- ing of the fill in a stope. With the materials used in the experiments in which the - 51 micron component of the tailings had been dis- carded, an optimum mix was found to contain 4:1 tailings/slag ratio and an overall pyrr hotite concentration of 8% (all proportion by weight). Approximately 34 days after drain- age to 15% moisture in natural air flow condit- ions, an unconfined compressive strength of 1.862 MPa was attained. A subsequent experi- ment was conducted with a sample of optimum mix in a pipe one metre long in forced air flow conditions. At a superficial velocity of 3.Om per hour the mix required 155 hours to harden to 1.862 MPa after drainage to 15% w/w moisture content. The pressure drop bet- ween the top and bottom of the mix in the pipe remained constant at 9 KPa/metre length. This result suggests that forced air flow conditions will increase the rate of hardening. No dangerous effluents were detected in the course of the experiments which could affect mine equipment or personnel.

Jan 1, 1973

Rajasthan of western India blessed with rich base metal and phosphorite deposits. The biogeochemical and geobotanical methods of mineral exploration are greatly used in parts of Rajasthan Zawar, Khetri and Ambaj multi-metal project Gujarat and Jhamarkotra phosphorite deposit. These principles are exclusively based on certain assumptions about the anomalous chemical composition in plants and distribution and migration of indicator elements. Biogeochemical studies for lead zinc deposit of Zawar group of mines were carried out to locate the probable accumulators which could help in prospecting for these metals. The important roots of Impatiens balsamia plants contain 735 mg. of cadmium and crotolaria linifolia 603 mg., melhania futteyporensis 626 mg. lindenbergia muraria 443, celosiu argentia 360 mg. In the Khetri copper belt the vegetation is scanty and the species includes Acacia arabica, zyzypus jujuba and cactus euphorbia.

Jan 1, 1988

By C van Wyk, I Reeves, J Webber, G B. Gnoinski

The minerals industry has been given an opportunity to grow and continue to advance again in an environment where there is the potential to reap big rewards for efficiency improvements due to buoyant metal prices and the growing demand of markets in Asia. Improving efficiency may also provide a better return compared to risks of expansions and bringing new projects online due to limited human and financial capital.An opportunity for improvement presents itself in the area of mine-mill reconciliation, which entails the quantification of the variance between measurement points along the mining value chain. Reconciliation factors are calculated from the variance between respective sections within the mining sequence. These factors are commonly used as key performance indicators to provide a check on the performance of the operations. Over parts of the mining value chain, there is a fair understanding of the reconciliation between the Resource and Reserve estimates and the measured metallurgical plant inputs and product outputs through understanding of the mine-mill interface. The quality of reconciliation data gathered across the mine and plant is generally not well established due to practices employed in generating the data. The reconciliation variances are often a function of data accuracy and quality used in the comparison. In general, the sources and magnitude of measurement and sampling errors and their impact on reconciliation are not that well understood. Examples of the current practices of mass measurement, sampling, sample preparation, chemical analysis and quality assurance for broken ore and across the metallurgical process stream are considered. Guidelines are given for those reconciliation elements that are identified as requiring a high degree of confidence for Mineral Resource/Reserve and metal accounting reporting. These guidelines are presented and practices are demonstrated to improve mine to mill reconciliation and support increased resource to product efficiency and value.CITATION:Gnoinski, G B, van Wyk, C, Webber, J and Reeves, I, 2012. Guidelines and practical applications for continuous improvement in mine to mill reconciliation, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 309-316 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

Natural leaching of minerals has been recorded for some two millenia but surprisingly only in recent years has enough been known of the process for any serious design to be made. Copper has been recovered from natural mine waters since about the 17th century but again little progress was made in de- sign procedures until recently. Natural or dump leaching was started as a recovery process late in the 19th century and in the years up to the classic study of Taylor and Whelan in 1943 a series of impirical optimis- ations made it a valuable process for treating low grade or waste material. The biological nature of Sulphide leaching was proven by Colmer and Hinkle in 1947 and since then a large mass of data has accumulated on the microbiology, biochemistry, and response of ores to this form of attack. In spite of this knowledge and the vast amount of pract- ical experience available there are few recorded attempts to present methods of calculation or design procedures that can be used for setting up a leaching process. A framework is given here on which such procedures can be based and indications given of the inherent advantages and limitations of the process,

Jan 1, 1969

Small mines exist because of a restricted deposit or a small market. With the right management at the present time the small mine can have lower total costs than larger mines. Charbon is an example of a small mine with a restricted deposit and a specialised product. The development which incorporates a unique rail loading facility and flexible coal preparation plant was achieved with a modest capital outlay and in record time. To remain competitive in future with large scale mines who seek increased production the small mine must achieve increased productivity through automation, higher speed equipment and a multiskilled workforce. Deregulation of the industry, scrapping the Coal Industry Tribunal and the Joint Coal Board would benefit small mines greatly. Management of a small operation also requires multiskills which need to be supported by outside help in the form of consultants and temporary staff. In the 21st century small mines will continue to provide a service to the market.

Jan 1, 1988

Magneto flotation is a recently developed method aimed at simultaneous utilisation of the magnetic and flotation properties of minerals in separation processes. In this method, magnetic minerals are prevented from reporting to the froth product while non-magnetic minerals are being floated. With suitable ores, this makes it possible to reduce or entirely eliminate the cleaning and scavenging operations that are otherwise necessary in conventional flotation and magnetic separation systems. This paper describes the testing of magneto flotation on a Canadian magnetite ore. The ore sample used in the experimental work contained a total of 32.89 per cent Fe of which 87.60 per cent was magnetic in the form of magnetite. Magnetoflotation yielded, in a single step, a final concentrate assaying 69.10 per cent Fe and with an overall recovery of 84.84 per cent representing a magnetic iron recovery of 96.39 per cent. Comprehensive comparisons were made with conventional magnetic separation and flotation, and it was found that with these methods at least four processing steps were required to achieve results similar to those obtained with single-stage Magnetoflotation.

Jan 1, 1993

By G Steward

Gravity Leaching of high-grade gravity gold concentrates, such as Knelson Concentrates, with the ACACIA Reactor represents a new generation of concentrate treatment methods. The ACACIA Reactor is a complete packaged plant for the maximising of gold recoveries from gravity gold concentrates. This paper will introduce the process technology and provide process results from the Porgera ACACIA Reactor installation. The advantages of the ACACIA Reactor are many, and justification for installation has been varied. The typical advantages of the process include: increased recovery of gold from the Knelson Concentrate; no return of high-grade table tails, often grading several thousand g/t, into the mill circuit; reduction in tails grades of slow leaching gold; reduction in the requirement for operating staff by the removal of the manual tabling process and replacing with a fully automated treatment system; improved security by removing the tabling step where operating staff come into direct contact with visible gold; improved health and safety, by the removal of the treatment steps for the table concentrate, which often include operators handling corrosive chemicals and the production of sulphur and arsenic compound fumes; and improved metallurgical accounting, by allowing daily head grade calculations. The ACACIA Reactor was developed by Anglogold for Union ReefÆs Gold Plant and has been in production for over two years, and has proven to be a low cost, high recovery, mechanically reliable method for the processing of gold concentrates. Such has been the success of the plant, there are now four full installations of the processing plant, including Anglogold Union ReefÆs, Anglogold Sunrise Dam, PACMIN Carosue Dam and Porgera Joint Venture.

Jan 1, 2002

By C J. Ptacek, J G. Bain, D W. Blowes

The passive interception and in situ treatment of groundwater using permeable reactive barriers (PRBs) has, within the past decade, become an accepted remedial approach to the control of plumes containing dissolved organic and inorganic contaminants. Since the first applications of the technology in the early-1990s, there have been several field-scale PRBs that have provided excellent treatment of dissolved metals in groundwater. Additional commercial applications and demonstration projects continue to be developed. Three field-scale applications and supporting laboratory columns have shown that several thousands of milligrams per litre of sulfate, more than 1000 mg/L iron, and several tens of milligrams per litre of other metals can be removed from groundwater by PRBs that promote sulfate reduction. The reactive materials, which incorporate various forms of organic carbon, promote microbially mediated sulfate reduction, the generation of hydrogen sulfide, and the subsequent precipitation of sparingly soluble iron and other metal sulfide minerals. Effective performance has been achieved by PRBs installed at a mine-tailings impoundment in 1995 (Sudbury, Ontario) and at an industrial facility (Vancouver, British Columbia). These PRBs have removed iron and other metals from groundwater. Similar materials were also used to create reactive layers within test cells directly in a tailings impoundment in 1999 (Timmins, Ontario) with the objective of removing iron and sulfate from the pore water before it migrates from the tailings impoundment. Zero-valent iron (ZVI) has been shown to provide excellent removal of chromium (VI) in a PRB, which was installed at the US Coast Guard facility in Elizabeth City in 1996, by reduction and precipitation reactions. Laboratory tests have also shown that ZVI reduces As(V) to As(III), which is subsequently removed from solution by co-precipitation with iron oxyhydroxides. In groundwater containing sulfate, ZVI and mixtures containing organic carbon can promote sulfate reduction and the subsequent precipitation of sparingly soluble arsenic and other metal sulfides. A trial PRB system was installed in 2001 and was shown to attenuate arsenic and other electroactive metals in groundwater at an industrial facility in northwestern Ontario. Basic oxygen furnace (BOF) slag, a waste material generated by the steel industry, has shown excellent potential for the removal of phosphate, elements such as arsenic and water-borne pathogens from groundwater in field and laboratory tests.

Jan 1, 2003

By Hongzhen Yu, Xiaoping Ma, Jiansheng Qian

The paper introduces the design of an Intelligent Managerial Attendance Machine (IMAM) for coal mines. In the system, data communication is carried by Optical fiber communication, including industrial control computer on the ground and the car

Jan 1, 1998