Search Documents

Observed mineral assemblages in the Mt. Lyell copper deposit can be correlated with phase equilibrium investigations in the systems Cu-Fe-S and Fe-Zn-S. The trend of crystallization (or paragenetic sequence) of the ores is reflected in a progressive increase in the Cu: Fe and metal: sulphur ratios of the assemblages. This trend agrees with the regional zoning of the district. Tentative relationships between the paragenetic sequence, sulphur vapour pressure, and temperature are presented graphically. The absence of a suitable geological thermometer prevents precise elucidation of the range of temperatures and pressures which existed during crystallization.INTRODUCTIONRecent phase equilibrium investigations of metal-sulphur systems at the Geophysical Laboratory, Washington, D.C. provide valuable information on the stability relations of a number of important sulphide minerals. This data, when applied to natural ore deposits, may be expected to clarify two special problems which confront the ore petrologist seeking to interpret observed data in terms of a particular physical and chemical environment of ore deposition. These two problems are the sequence of formation of sulphide minerals (commonly designated the paragenetic sequence) and an elucidation of the range of temperatures and pressures which existed during crystallization. The object of this paper is to make such an interpretation of the copper mineralization of the Mt. Lyell district, Queenstown, Tasmania.The following abbreviations are used in this paper:py = pyrite, cp = chalcopyrite, en = cubanite, bn = bornite,cc = chalcocite, cv = covellite, dg = digenite, id = idaite,po = pyrrhotite, v = sulphur vapour.GEOLOGICAL SETTING AND MINERALIZATIONThe general geology of the Mt. Lyell district is well known through the recent work of Wade and Solomon (1958). The host rocks are a series of quartz-chlorite-seri-...

Jan 1, 1963

FROM time to time articles have appeared in the technical press on the interesting subject of surface combustion. The theoretical part of the problem has, for practical purposes, received ample consideration in those articles, but the number of practical applications of surface combustion referred to has generally been very small.It is the writer's object to review some recent developments in surface combustion, and also to try to arrive at an estimate of its advantages and possibilities. It is not necessary for this purpose to dilate upon the phenomenon of surface combustion itself. Many interesting things have been said on the subject by Pro£. W. A. Bone, of Leeds, to whose researches the recent developments are largely due. A few illustrations may make clear what is meant by surface combustion.Prof. Bone, in an experiment, took a platinum crucible, which he heated in the flame of a Meker-burner. Then he turned the gas off for a second, and, opening the stop-cock again, allowed the combustible mixture to impinge upon the crucible, thetemperature of which was still well below the ignition temperature of the gas. Although no flame was visible at this stage, it was soon clear that, nevertheless, the gas and air had continued to combine, as the crucible would attain a red heat after a few seconds.Another instance of surface combustion was shown by a Mr. Fletcher, in 1882. He placed an iron ball, weighing 3 lb., on a slab of fireclay, heated it for a few seconds with a blow-pipe, and blew the flame out, leaving the gas-mixture still...

Jan 1, 1915

By Monger N. R

Factors leading to the decision to use Joy Continuous Miners for pillar extraction in the Burwood Colliery are outlined. A detailed description is given of the Joy 1-CM-2 Continuous Miner, including the power supply to the machine, and the method of cutting coalfrom a face. Modifications found necessary in practice are dealt with.The Joy 10 S.C. shuttle car used in conjunction with the Miner, and alterations made to this unit, are then described, together with Ancillary units for the whole installation such as transformers, motor generator set, air compressor,_ cables for power supply and water supply for dust suppression.Special arrangements were necessary to transport the Miner and Shuttle Cars through the tunnel to the Victoria Tunnel seam, and the method of overcoming the transport difficulties is discussed. Manning of the Continuous Miner unit, and final preparation andsubsequent working of the pillars is outlined. Special attention must be given to maintenance of the machines.It is concluded that the combination of Joy Continuous Miner and Shuttle Car is an excellent method for removing pillars in the Burwood Colliery.INTRODUCTIONThis paper deals with the Burwood Colliery in the RH.P. Group in which some units are engaged in the mechanical extraction of pillars with Joy Continuous Miners.In 1941, an amendment to the Coal Mines Regulation Act of N.S.W. forbade the extraction of pillars by mechanical means unless with the express permission of the Minister for Mines. As this permission was not forthcoming, no mechanical extraction of pillars took place in Australia until 1954 As it was doubtful during most of this period whether mechanical extraction would ever come about, coal generally was won with a view to maximum extraction in the first workings, thus giving rise to centre gannon bord panels and 45° angle cut throughs as shown in Fig. 1.

Jan 1, 1957

FREQUENTLY the Survey Department is caIled upon to estimate the quantity of material in various dumps, dams piles, etc... and in the carrying out of this work various methods may be employed.The method used will vary according to the particular case in hand, and factors such as accessibility of the top of the dump, steepness of its sides, height, and the condition of the material to be estimated. A certain amount of "give and take" must be adopted in the treatment of small local cavities and mounds.In all cases it is desirable that the surveys made should be tied on to the lease surveys for the purpose of location, and that all levels should be reduced to the mine datum. It is also desirable to obtain levels of the original surface before deposition of the material to be estimated. If these have not been obtained beforehand, levels and transfers round the top will be the next best. If space is availabIe, flat surface is chosen as a site for the dump, etc. This is of the utmost importance in those cases where the material will have to be...

Jan 1, 1925

By D Craw, I M. Turnbull, R J. Norris, N Mortimer

The Otago Schist is being subdivided on a regional scale into structurally, metamorphically and lithologically distinct blocks. Differences between blocks are subtle, and difficult to map in the field. Boundaries are late-metamorphic or immediately post-metamorphic in origin, and are different from later brittle faults which disrupt the schist. Mapping of late-post-metamorphic structural discontinuities has direct application for basic grassroots exploration in the Otago Schist. The mineralised (and currently mined) Hyde-Macraes Shear Zone forms a regional scale boundary between a block dominated by politic schist and a block with massive psammitic schist, pelitic schist, and minor greenschist and chert. The HMSZ forms a metamorphic discontinuity, with garnet and biotite in the underlying schist, and neither index minerals apparent in the overlying schist. The HMSZ is also a structural boundary between domains with differing lineation orientations. The HMSZ can not yet be traced along strike to the northwest to the Rock and Pillar Range, where the only major discontinuities recognised are the Caples-Torlesse boundary and a normal fault separating low grade from high grade schist. Structural and lithological discontinuities in the Dunstan Range break the range up into distinct structural blocks, two of which are separated by the gold-mineralised Rise and Shine Shear Zone.

Jan 1, 1999

CONTENTS:1. Introduct'iona. Previous Accountsb. Summary of Geologyc. Physiography2. Morgan Groupa. Lithologyb. Structurec. Faulting3. The Mineral Deposita. Descriptioni. Size and Shapeii. Compositioniii. Effects of Oxidationb. Relationship to Structurec. Genesis of Ored. Mount Morgan Orebodye. Sugarloaf Orebody4. Granitea. Mount Morgan Graniteb. Town Granite'c. Moonmera Granite5. Calliungal Beds6. Razorback Beds7. Acknowledgments8. References

Jan 1, 1952

Refractory gold ores have been the subject of intensive metallurgical study in order to achieve more efficient recovery of contained values and at the same time to minimise environmental impact. Considerable innovative gold processing technology was introduced in New Zealand last century, the most notable being the first successful commercialisation of the cyanidation process by the Crown Mines Company at Karangahake in 1889. The Karangahake gold-silver deposit was second only +to the Waihi Martha mine in total bullion production from the region with active mining from 1882 until about 1920 and sporadic production between 1930 and 1944. Reevaluation at Karangahake with associated metallurgical testing has continued since that time becoming particularly active in the last decade as a result of increasing gold prices. Gold processing technology is reviewed and results of some recent test work are presented and discussed in the context of Karangahake history and future development possibilities. This work confirms the variability and complexity of the Karangahake deposit both mineralogically and metallurgically and suggests flotation followed by new and innovative smelting is the most appropriate processing route for the recovery of gold from the high grade ore which could be produced from the Karangahake workings in moderate tonnages.

Jan 1, 1993

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

E. W. Stutchbury (Internationa~ Oombustion Aust. Ltd.) : Mr. Callcott made particular mention in his paper of erosion in primary air fans which are placed after the mill discharge. He adds that subsequent reduction in plant performance and resulting increased maintenance costs occur. It is generally assumed that this statement is substantially correct as the fan handles the complete output from the mill, but with modern materials, reduction in performance and subsequent .maintenance are not now a problem. This consideration of handling the pulverised coal in the fan is more than offset by the advantage of operating the mill under suction which results in cleaner operating conditions, simpler feeder arrangements and elimination of complicated seals on the mill.and feeder unit. It should be specially noted that whereas mill exhausters in the past have used chequer plate blades (sometimes with the addition of hard facing by electrode deposit) it is modern practice to provide fan blades of up to 1 in·. thick Ni-hard suitablyheat treated, with the circumferential section of the fan also in Ni-hard. By the use of this material large power...

Jan 1, 1957

Of the world's total production of gold the largest proportion comes from the more regularly consistent ore bodies, but in the aggregate an important part comes from those which are often irregular, uncertain and small. These smaller ore bodies are often high in grade and, as the capital required to work them is not large, they appeal to people seeking a quick and profitable return for a small outlay.These small mining concerns cannot afford detailed geological and petrological investigations and mapping, so they are very often dependent on local knowledge and experience which admittedly may be of really great value.Nevertheless the absence of skilled guidance may not only cause good opportunities for intelligent exploration to be lost, but discourage the seach for other ore bodies.lVIining engineers in the course of their travels in the examination of mines often come across such cases and also others where problems of finding lost ore bodies have been solved by the man on the spot. As records of cases are valuable and useful additions to the knowledge of ore occurrences, the writer now proposes to describe one such case coming under his observation in recent years.It is that of a small mine, known as the Idaho, at the southern end of the famous "Golden Mile" at Kalgoorlie (see Fig. 1). This mine has been a small and very erratic producer ever since it was abandoned by an English company which owned it forty years ago. Except for one period of four years it has always been owned and worked by parties of co-operative miners and during its time has gone through a tortuous career. Although it has often...

Jan 1, 1938

New Zealand China Clays produces a unique halloysite clay product at Matauri Bay, Northland.   The company has licences over four deposits that were derived from the weathering of rhyodacite domes. Clay is mined and processed from two of the four deposits and is refined using a complex process based on gravity separation.   The product is almost entirely exported to niche markets in 24 countries. The main market is the fine ceramic industry where the product is used as a component in the manufacture of high quality porcelain and bone china bodies. The use of halloysite in these bodies gives the manufacturer the ability to achieve high whiteness and translucency. The other major market is for use in technical ceramics, where the product is sought after due to its high purity, fine particle size and stability at high temperatures.

Jan 1, 1997

By Boden A

A procedure was developed for recovering metal values from copper-smelter fume. The fume is first leached to neutrality with dilute sulphuric acid to obtain a solution of zinc sulphate containing a low level of impurities. The tailings from this leach are treated with hydrochloric acid in two stages, in which tin and zinc are quantitatively leached and recovered as a tin concentrate and a zinc sulphatelzinc chloride solution.About 80 per cent of the lead sulphate is converted into lead chloride, which can be recovered as a pure product.Data on the effect of temperature, acid concentration, aeration, and solid/liquid ratios on the hydrochloric acid leach are presented, and the fate of the most important metals during the recovery process is described. Alternative treatments of the tailings from the neutral sulphuric acid leach were briefly investigated.

Jan 1, 1977

THIS has been a much-neglected branch of engineering. With the majority of industries labour is the chief item of trouble and expense. Anything that will reduce trouble and increase efficiency is well worth considering. It is only of recent years that any attempt has been made on a scientific basis to improve conditions sporadic attempts having been made from time to time, privately and by law. Some have been successful, others unsuccessful not necessarily the fault of those who initiated the ideas, though naturally mistakes were made in some cases for want of experience, but those whom it was desired to benefit were not always prepared for the change, and by their distrust hampered schemes instead of assisting them.Man power is generally more expensive than machinery, though there are exceptions, such as when a small amount of work has to be done in a place where machinery does not exist, and it would not pay to instal any or where labour is cheap, and skilled workmen are scarce as in some tropical countries. When machinery is first introduced it generally causes the suspicion that it will deprive men of their work. It may cause men to vary the conditions of their work, and in some individual cases, when men are unable to conform to changed circumstances it may result in a certain amount of hardship; but, after all, the less competent must not hold back progress for the general good. Besides, changes as a rule do not take place suddenly, so old hands can generally find work at their particular calling 'till nature requires them to retire. In cases where men take to machinery, they not only find that they are relieved of the...

Jan 1, 1918

Yallourn brown coal and its characteristics have been the subject of innumerable papers and discussions. The Lurgi process adopted for the production of Towns gas by the gasification of brown coal has been described frequently in literature.The application of the Lurgi process for the gasification of Yallourn briquettes has naturally lead to some unexpected problems. Rather than attempt to review the whole field of experience gained in the first two years of operation of the gasification plant at Morwell, this paper attempts to describe two problems encountered, peculiar to the fuel used, and the steps taken in overcoming them.THE PROCESS AND PLANTTo clarify the conditions surrounding the problems, it is necessary to briefly describe the gasification and cooling processes and plant.Brown coal briquettes are gasified in a pressure generator, using a mixture of steam and oxygen as a gasifying medium. Crude gas produced in the generator is washed and cooled in the waste heat boiler and coolers. Figure 1 shows an arrangement of the generator and coolers. The gasifying medium enters the generator through a hollow shaft in the base. This shaft drives the grate, which has three purposes: (a) to distribute the gasifying medium into the fuel bed; (b) to extract the ash from the fuel bed; (c) to support the fuel bed.Briquettes enter the top of the generator through the coal lock chamber and the fuel bed is maintained at a reasonably...

Jan 1, 1960

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

By Bratt G. C

When zinc is electrowon from concentrates or residues of high manganese content, the zinc sulphate electrolyte may contain high levels of manganese. The manganese level is usually controlled by removal of manganese at the anode as the dioxide during the zinc electrodeposition stage.By increasing the temperature of an electrolyte containing 8 gll manganese from 35°C to 90°C, decreasing the acidity from 100 gll to 30 gll, reducing the current density from 432.A.m-2 t6 286 A.m-2 and using new lead anodes containing over 0·75 per cent silver, the current efficiency for manganese dioxide removal was .increased from less than 1 per cent to over 20 per cent.At the same time the current efficiency for zinc deposition was maintained above 90 per cent by additions of high molecular weight cationic polyacrylamides to the cell. By utilization of these conditions in a small number of cells, the manganese level in the circuit could be economically concrolled to any desired level.With these conditions the formation of the dioxide changes from an indirect route, via Mn04-, to a direct oxidation of Mn2+ to Mn02.The incorporation of impurities such as Pb, K, NH4, Cu, Ni, or Fe makes the deposit unsatisfactory for direct use in Zn - Mn02 dry cells. The deposit structure changes from cryptomelane at low temperature to y3-Mn02 at high temperature.

Jan 1, 1975

By A Priatna, H Rumbino, T Casten

This paper discusses the progress of the Deep Mill Level Zone (DMLZ) mine from the pre-feasibility study completed in 2005, through commencement of development access in 2008, completion of the feasibility in 2010 and cave initiation in late 2015. This fourth lift of caving in the East Ertsberg Skarn System (EESS) is located 500 m below the currently producing Deep Ore Zone (DOZ) mine and represents approximately half a billion tonnes of ore and around 1900 planned drawpoints, scheduled to be mined at a peak of 80 000 t/d.The paper reviews the mine design, access requirements, planned footprint sequence and major fixed facility installations such as ventilation, oreflow and shops. A discussion of the preproduction development and construction activities and some of the critical technical challenges overcome during this time frame are addressed, as well as the cave initiation process undertaken in late 2015 and the ramp-up of production and progression of caving.CITATION:Casten, T, Priatna, A and Rumbino, H, 2016. Deep Mill Level Zone – from feasibility to production, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 635–644 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

At the inception of the gold-mining industry at Kalgoorlie the small supply of firewood required for steaming purposes was naturally all drawn from the limited local areas, which promised soon to become denuded. With the advent of the railway toKalgoorlie came the ever increasing machinery and steam power, and the accompanying demand for firewood so increased that the fuel contractors began their operations, by following the timber belts along the Yilgarn railway line, and graduallygetting further westward, until at present we find them as far as Woolgangie, 63 miles from Kalgoorlie, and with the regular railway rates, I0. per ton per mile, this maybe considered the limit of payable timber at current rates. Although in the early days the reserve of timber along the railway line must have appeared as incalculable and inexhaustible as that of coal did in Europe a couple of centurys ago, the day is now near us when even this source will fail to meet the demands made upon it, for, although a good two years' supply is available or the areas under the axe, yet it is time to look ahead and find from whence the future supplies are to be drawn. Along the railways we find the zone of felling operations limited for want ofcommunication, and only such portions of the forests as are within six or seven miles of the railway come under the axe at present while virgin forests to the rear remain practically unexploited. It is only in the course of the past sixteen months that the firewood industry has developed...

Jan 1, 1901

By S Telford, J Weir

Heathgate Resources Pty Ltd (Heathgate) operates the Beverley Uranium Mine in South Australia, located on the plains between the northern Flinders Ranges and Lake Frome some 600 km north of the state capital Adelaide. The uranium orebody exists in permeable sands within the confined, highly saline Beverley aquifer, approximately 125 m below the ground surface and the uranium is mined using in situ recovery (ISR) technology. The Beverley mine is a highly technologically advanced ISR mine and is operated in accordance with stringent safety and environmental standards. The mine is currently licensed to export 1500 t of uranium oxide (U3O8) per annum. This paper outlines the fundamental differences between ISR operations and the more traditional uranium production methods, such as agitation leaching and heap leaching, where the ore is removed from the deposit, stockpiled, crushed, milled and leached on the surface. Solids tailings from either the mill or the heap are finally deposited in a tailing storage facility. ISR mining differs from conventional mining because the ore remains in place underground (in situ) and the groundwater contained in the ore-bearing aquifer is utilised as the mining fluid. This is achieved by drilling into the deposit and installing wells for extracting and re-injecting the groundwater which is fortified with chemicals. The fortified groundwater (ie mining fluid) flows through the permeable sands containing the orebody, dissolving the uranium. The pregnant mining fluid is then collected and transferred to the recovery plant where the uranium is captured (on ion exchange (IX) resin in the case of Beverley). The barren mining fluid is then re-fortified and recycled to the wellfields. Once mining is completed in a wellfield, the surface infrastructure is relocated to a new wellfield, and the mined-out wellfield is rehabilitated to its original surface condition. A comparison of 'standard' hydrometallurgical plants, heap leach and ISR shows a number of key differences, such as the rate of leaching, the level of control available to the operators, and the type of contact/reaction that occurs. While limited in its applications, ISR mining has proven successful at Beverley and provides another mining and processing method for the production of uranium.

Jan 1, 2008

By Van Dusen M

The involvement of concerned parties in all aspects of the Lihir Project from an early stage has promoted good relations between all groups. Activities involving landowners, the Lihir community, the New Ireland Provincial Government (NIPG) and the prospective developer include the Lihir Liaison Committee, Lihir Working Group, Environmental Planning Committee, Provincial Mining Task Force and the Lihir Mining Area Landowners Association (LMALA). With modifications, the Lihir Liaison model may be of use in promoting good relationships among parties in other mineral developments.

Jan 1, 1991