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Traditionally trucks have dominated haulage in open pit mines. Only recently have conveyors begun to be used in the long haul and high lift duties of surface mines. Steep angle conveyors are proven versatile systems for elevating or lowering materials continuously at steep angles to 90¦. This paper describes the design of a bucket-type steep angle conveyor that was developed as a joint research project between the Western Australian School of Mines and the Maanshan Institute of Mining Research in China. The steep angle conveyor can be used as a viable option for transporting blocky ore from open pit mines. A pilot conveyor was constructed and tested to determine its technical and operational feasibility. Furthermore, a computer model based on Matlab mathematical modelling software was developed to simulate the performance of the pilot conveyor. The model enabled to determine the design parameters of industry-scale conveyors to yield satisfactory performance. These conveyors become very cost-effective for those mines having large mine lives and depths greater than about 500 metres.

Jan 1, 2003

After a five year period representing the strongest resource and commodity rally ever experienced, we are now faced with a subdued recovery following the global financial crisis. This renewed economic growth will be steady but eventually attain levels that reignite export demand out of China and other emerging nations, which are now reliant on increasing domestic demand to support their economies. This backdrop of weaker share prices and less available investment capital creates a greater imperative for company management to ensure that its share price is fully valued. The mining geologist plays an important role in achieving this outcome through direct estimation of asset value (resources) but also in strongly communicating the æupsideÆ value opportunity in both mine site and adjacent brownfields exploration and an efficient and technically sound mining operation. The contribution of mining geologists to assist in conducting analyst site visits should not be underestimated, particularly with reduced analyst coverage of the resources sector and some simplification in company analysis through ranking companies on Reserve and Resource positions.

Jan 1, 2009

MR. W. E. WAINWRIGHT occupied the chair, and in introducing the lecturer said, on account of the absence of the vice-president, it fell to his lot to introduce the lecturer. Mr. Tennberg, he said, was visiting Australia, and those present might wonder who he was.He understood that the lecturer w~s a reputable practising geophysicist, associated with a reputable company! It was rather desirable perhaps to say that the Institute had made some inquiries with regard to his status. Geophysics was a comparatively newscience, and had suffered several hard knocks in Australia and elsewhere. Most of those knocks had been the result of undue optimism of a number of people who did not understand what they were talking about. It had been claimed that geophysics was a...

Jan 1, 1930

By J T. Woodcock, G J. Sparrow

A sample of pyrrhotite flotation concentrate pulp assaying 15.3 g/t Au, which had been prepared from an old tailing dump, was treated to extract the gold. Examination of the concentrate with an SEM showed that exposed or free native gold, 5- 40 ¦m in diameter, was present but no locked gold was observed. Direct cyanidation of the concentrate to extract the gold showed that the flotation reagents present inhibited gold extraction. A range of pre-treatments was used to overcome these effects. Direct cyanidation for 48 h extracted only 26 per cent of the gold, indicating possible contamination of the gold in the concentrate with flotation reagents. Pre-treatment of the concentrate pulp by aeration for 24 h, or by 72 h aeration with an addition of 3.65 kg/t of sodium sulphite, gave little improvement in gold extraction by subsequent cyanidation. Pre-treatment by filtration, or by aeration with 12.5 L/t 100 volume hydrogen peroxide, followed by cyanidation for 48 h gave gold extractions in the range 67-77 per cent. Combining filtration and an aeration period with hydrogen peroxide addition raised the subsequent cyanidation extraction of gold to 88 per cent, giving a tailing assaying 1.5 g/t Au. Re-cyanidation of some of the dried tailings from the initial tests extracted most of the remaining gold giving a tailing assaying 0.5 g/t Au. This indicated that most of the gold was available for dissolution by cyanide. The poor dissolution of gold by cyanidation of the untreated concentrate was attributed to the presence of flotation reagents. It was shown by UV spectrometry that xanthate-containing compounds were present in the solids fraction of the original pulp and that they were partly removed by pre-treatment. MIBC was also present, and dithiophosphate, which was used in the flotation step, was also probably present. The results indicated that the improvement in gold extraction after filtration and oxidation of the original pulp was due to partial removal of the flotation reagents, and illustrates the detrimental effects that residual flotation reagents can have on the extraction of gold by cyanidation of a flotation concentration.

Jan 1, 1990

By d&apos, Alton AJ, Rigden DT

Modern petroleum refining offers a complexity of environments, each requiring different metals for the satisfactory performance of-the various sections of the refinery, and this paper first outlines the varied enva.x¦on-ments thus met.It follows that the metal types in use will also vary to suit each particular environment, and the paper' consequently covers the use of ferrous-metals, ranging from plan carbon steels to the high alloy types and the non-ferrous metals, particularly copper and its alloys.The failures of some,of these metals and alloys are then illustrated by experiences it Kwinana. These failures are duo to (a) corrosion, (b) erosion, (c) faulty welding, and (d) mechanical defects,' of which the first is by far the most prevalent. The protective measures taken to prevent subsequent failures are then given under one or other of the following headings :(1) alterations in process conditions, (2) the use of alternative ,alloys,(3) suitable heat treatment, (4) redesign of the failed section, (5) cathodic protection, and (6) use of corrosion inhibitors.Reference is then made to the use of specialised metals and alloys.Metals, generally in the form of oxides or salts, are also used as catalysts in refining processes. Activated alumina is used, combined with silica .forScracking' of heavy oils, and as a support -for platinum, cobalt, molybdenum, nickel and similar metals, which catalyse hydro-genation and dehydrogenation-processes. .In the final formulation of petroleum products metallic compounds may be added. Reference is made to the large quantities of lead used by the petroleum industry and to the use of metallic soaps and detergents in the formulation of lubricating oils and greases.

Jan 1, 1962

The last two years have seen a rapid change-over from mechanised cut and fill. stoping to the more economic and productive long hole open stoping method, such that today more than 80 per cent of total production is won from open stopes. At first drilling was by sub-level rings and/or parallel up and down holes from inter- mediate sill horizons using conventional exten- sion rod equipment. Sub-levels were developed no more than 40 metres apart to allow accurate drilling. Compact, crawler mounted in-the-hole hammer equipment was introduced as soon as it became available in Australia. Today, all open stope drilling is done with three Atlas Copco ROC306 rigs and two Ingersoll-Rand CMM jumbos. Fans of 115 mm diameter holes, varying from near vertical down holes to horizontal, are drilled with a burden of 3 m. Toe spacing varies from 3.5 m to 4 m. An Atlas Copco DG418 booster compressor is used to boost run-of-mine air from 700 kPa to 1400 kPa in the areas of longest drilling. This has improved overall drilling performance in these areas by 40 percent.

Jan 1, 1977

Research and Technical Services, Department of Mines Western Australia The nine papers received for this technical session cover a very wide range of hydrological problems in various parts of the world. Three of these papers deal with hydrological predictions for new mines, while three are concerned with the prediction of water chemistry. The three remaining papers deal with gas injection as a dewatering tool, discharge formulae verification and the use of a physical model to predict subsurface strata movement and fracture development due to longwall mining. Hydrological problems in mine planning represent a major risk in many mining operations, booth as a potential life or equipment hazard and a major financial risk. The initial paper selected to review was therefore one by the president of a gold mining company, rather than by one of the specialist scientists, to remind us all that the main reason problems are faced and overcome in the mining industry is usually a commercial one. In one commercial undertaking, the ability to accurately assess future risk is a highly desirable planning tool and hence in mining, the ability to predict the nature and magnitude of hydrological problems is n i-an varxi imnnrfant

Jan 1, 1988

By P K. Smith, N G. Corner, R J. Ryan, D C. Arne, F P. Bierlein

The Reefton Goldfield has produced 67 t of gold from mesothermal vein gold deposits in metasedimentary rocks of the Greenland Group (Cambrian-Ordovician). The Globe-Progress deposit contributed 13.2 t (418,000 oz) of this total, predominantly from quartz veins. Recently a resource of 14 Mt at 1.96 g/t Au (27.5 t or 882,300 oz of contained gold) has been delineated at Globe-Progress in quartz vein remnants and disseminated within adjacent sedimentary rock, much of which has been locally brecciated. The breccias consist of quartz vein and sedimentary wall rock fragments set in a matrix of clay ærock flourÆ and sulphide (arsenopyrite plus minor pyrite and stibnite). Gold, closely associated with sulphide, is disseminated within the breccia. Disseminated gold also occurs in massive siltstone and sandstone adjacent to the quartz veins and breccias. Exploration drilling at Globe-Pogress, and several other Reefton prospects (e.g. Capleston, Merrijigs, Big River and Alexander River), has intersected zones of disseminated arsenopyrite carrying up to 20 g/t more gold. These mineralised sediments commonly have little or no megascopic quartz and or carbonate veining. There is little visible indication of former primary or secondary permeability for the passage of hydrothermal fluid and deposition of gold. However, porosity and permeability were formerly present in inter-granular pore spaces and microveinlets now filled with quartz, carbonate and K-mica. The Fosterville gold deposit in Victoria bears many similarities to the Globe-Progress deposit at Reefton, in terms of age, host rocks, hydrothermal alteration and mineralisation style. Many ofthe disseminated deposits in Nova Scotia, including deposits at North Brookfield and Moose River (Touquoy Zone), have similar characteristics to the Reefton disseminated mineralisation, but commonly have abundant pyrrhotite and some deposits have disseminated metal alloy grains of complex metallurgy.

Jan 1, 2000

Legislation, if it is to be effective, must be enforceable by the state and acceptable to the industry. In the mining industry the relationship between the government inspector on the one hand and the mine management and employees on the other, must be one of full co-operation before the system can be effective. To understand our present system, which is-duplicated in most countries of the world, an examination of the history from which it evolved is necessary.

Jan 1, 1975

Magnetic anomalies in the Southern Coalfields have been subdivided into two characteristic types. Each type is attributed to a separate cause, one being basement structure, and the other near-surface igneous intrusions.Detailed geological mapping of the area and the ability to sample throughout the coalmines greatly assisted in this subdivision.The Triassic sequence contributes no magnetic effect of its own except to diminish the effect of sources within the underlying formations by raising the level of observation.Detecting the presence of igneous intrusions ahead of colliery working faces by magnetic observations within the coal mines may be of value in preventing accidents caused by gas outbursts and in planning the workings so as to avoid loss of production time.

Jan 1, 1967

With a price slowly rising above US$35 per ounce gold became a mineral worthy of prospecting and mining endeavour in the early to mid 1970s. Fortune therefore appeared to smile onNew Zealand with its favourable geological environment for gold and past record of major gold production from both hard rock and placer deposits. This was a particularly welcome development as the post war years, including both the base metal exploration boom of 1967/1971 (which produced major nickel, iron and bauxite mines in Australia) and the earlier period of uranium exploration failed to produce any mines in New Zealand with the exception of the small Tui Mine and iron sand mining. Whilst hard rock mining now appears imminent it is 15 years further along the track since the 1967/1971 exploration boom and eight years since the upsurge in prospecting for gold in 1978. New Zealand still has no hard rock base or precious metal mining. This is not for want of proven or potential gold mining situations for these clearly exist at Waihi, Monowai Reef, Golden Cross, MacRaes Flat and elsewhere.

Jan 1, 1986

By Van Weert G

Ferrous chloride solution pyrohydrolysis is a successful IICI regeneration process which is carried out in either a spray roaster or a fluid bed. Pyrohydrolysis is not restricted to ferrous chloride only, every metal chloride can theoretically be hydrolysed. In practice, however, the conditions for ferrous chloride pyrohydrolysis differ from those of many non-ferrous metal chlorides eg zinc, lead and cadmium. Hence, a pyrohydrolyser could function as a ferrous/non-ferrous separator, eg an iron oxide and zinc chloride separator. Most pyrohydrolysers operate on solutions, in which case more than 50 per cent of the process energy is needed for heating and evaporating water. However, this disadvantage would be diminished by feeding a slurry to the reactor. Against this background it was decided to investigate the chloridisation of zinc ferrite which is an iron bearing solid with a non-ferrous impurity, and subject to processing and disposal problems. Synthetic zinc ferrite was chloridised in a tube furnace. The gas atmosphere in the tube furnace resembled that of a fluid bed pyrohydrolyser and consisted of HCI, 1120 and nitrogen. Gas composition, temperature, residence time and sample mass were varied. The experiments showed that complete (99.6 per cent) zinc extraction from synthetic zinc ferrite was possible in a simplified pyrohydrolyser atmosphere at 1100 K in four hours. The zinc ferrite was converted into gaseous zinc chloride, and hematite and magnetite solids. It was also found that zinc removal from the zinc ferrite lattice caused not only rccrystallisation of the zinc ferrite into hematite, but also hematite crystal

Jan 1, 1993

Dartbrook (Hunter Valley and South Bulli (Southern Coalfield) Collieries provide contrasting settings for gas sorption studies. Gas compositions at Dartbrook are dominated by carbon dioxide, with minor methane, while those at South Bulli are dominated by methane with minor carbon dioxide. Total gas contents at Dartbrook are also significantly greater than those at South Bulli. The two collieries are also contrasted in terms of coal composition and mining environment. Dartbrook Colliery mines a relatively small sectionb(4m) of very thick seam (up to mapproximately25m); the coal is vitrinite-rich, high volatile bituminous. South Bulli mines most of the seam thickness, with coal being an intertinite-rich, medium volatile bituminous coal.Coal samples have been collected from in-seam gas drainage holes for evaluation of relative gas desorption rate (methane versus carbon dioxide). Following adsorption isotherms, petrography, chemistry (proximate and ultimate analysis) and pore structure analysis (carbon dioxide surface area, mercury porosimetry). Bomb desorption studies indicate different behaviours for methane desorption at these two collieries desorbed gas compositions at South Bulli show a small enrichment in methane content. The opposite is observed at Dartbrook. Both collieries show enrichment in CO2 in the residual content. Adsorption studies show marked variation in adsorbed gas contents for methane and carbon dioxide at each colliery and between collieries. These variations are related to differences in coal pore structure, chemistry and Petrology.

Jan 1, 1998

Peko Mines, a Division of Peko-Wallsend Operations Limited (PWOL) has operated several small underground mines in the Tennant Creek district of the Northern Territory supplying ore to a central treatment plant. The Argo Mine is the most recently developed by Peko Mines. A magnetic anomaly was identified from low level airborne magnetics in 1960 and drilling, which commenced on the site in 1969, was halted in 1974 and resumed in 1980 following the rise in the price of gold. By mid 1983 a resource of + 200 000 tonnes of 12 g/tonne Au had been outlined and a decision to develop the resource was taken following the drilling of three further diamond drill holes which did not significantly alter the value of the resource. The small size of the orebody could not support the full capital cost of two shafts and a single entry mine plan was developed to extract the ore at a rate of 15 000 tonnes per month and to provide all the safety features, ventilation systems and services of a two shaft mine. In December 1983 a contract was let to Allied Constructions Pty. Limited (Allied) to sink and equip a 4.8m shaft to a depth of 410m and to convert the headframe and winder, which are leased for the life of the mine by PWOL from Allied, from a sinking to a production configuration. Shaft equipment designed by Hardcastle & Richards Pty. Ltd. (H & R) in conjunction with PWOL includes a skip/cage, counter- weight, and an auxiliary cage on rope guides, a sealed ladderway and exhaust air ducts.

Jan 1, 1986

By D K. Miller, L W. Armstrong

In April 2006, Orica Quarry Services undertook an investigation to determine the likely vibration and frequency response of three water storage tanks to quarry blasting, immediately adjacent to the tanks. Of the three tanks that were studied, two are relatively tall with a æwineglassÆ shape; one is constructed of steel (4 ML storage capacity) while the other is constructed of concrete (2 ML storage capacity). The third is a ground-embedded concrete tank that is relatively squat and broad in shape (38 ML storage capacity). A vibration limit of 25 mm/s and an acceleration limit of 0.16 g were imposed on the tanks. However, this report shows that this acceleration limit, whilst having relevance to low frequency earthquake motions, is quite inappropriate for the high frequency blast vibrations that are typical in a quarry blasting environment. The investigation involved firing 11 single blastholes of known charge weights and distances from the tanks, and measuring the tank vibration response using blast monitors placed on and around each tank. Analysis of the data collected from the cement tanks showed resonant responses over a broad range of frequencies, with dominant and lesser responses in vertical and lateral motion recorded at 9.8 Hz, 12 Hz, 16.8 Hz, 17 Hz, 31.3 Hz and 38.1 Hz. Unfortunately, most of the data collected on the steel tank was corrupted by noise due to electrical sources and/or mechanical sources such as the water agitator inside the tank. Advanced Monte Carlo vibration models were then constructed using the single blasthole information. Knowing the resonant frequencies enabled the modelling of electronic delay sequences for the reduction of resonant vibrations. Ultimately programmable and accurate electronic delay detonators were deemed essential to allow blasting in relatively close proximity to the tanks while avoiding resonant frequencies. Three blast designs were modelled, ranging in maximum instantaneous charge (MIC) from 4 kg to 22 kg, and 60 holes to 160 holes. The modelling showed that two of the designs (using small charge weights) could be used no closer than 71 m from the storage tanks. This is based on a 90 per cent confidence level of achieving vibration levels within the 0.16 g acceleration limit, even though the velocity levels predicted to be generated at this distance were significantly less than the 25 mm/s limit. The third design incorporated larger charge weights and could be used for blasting at distances no closer than 220 m from the tanks. The present work, conducted in an operating quarry, demonstrates the usefulness of Monte Carlo waveform superposition techniques for the control and reduction of ground vibration (either velocity or acceleration) under restrictive environmental constraints. However, a discussion is also presented to demonstrate that it is somewhat restrictive to impose an acceleration limit based on the motion produced by low frequency earthquakes rather than the motion produced by high frequency blast vibrations.

Jan 1, 2007

For decades strip mining with discon tinuously operating 'draglines and shovels has been the most economical operation method in the shallow hard coal opencast mines of Aust- ralia, North-America and some other countries. Continuously operating equipment such as bucket chain excavators and bucket wheel excavators in combination with conveyor belt systems, conveyor bridges and stackers had been deve- loped in Germany; during the last 25 years this type of equipment has been further developed in order to allow a high degree of rationaliza= tion as to opencast mines in unconsolidated overburden in Germany, in many European couh- tries, in India and in Victoria. The differing compactness of the layers to be mined, the increasing mining depth, the adverse over- burden to coal ratio and geotechnical con- ditions account for the combined use of con- tinuously and discontinuously operating equip- ment and systems. This paper is to demonstrate some projects showing the combination of continuously and discontinuously operating equipment which aims at optimizing opencast mine operations. It will be reported on the following combinations: - combined use of bucket wheel excavator/

Jan 1, 1981

New Zealand has been a significant producer of gold for over a century. Total recorded production is over 850 tonnes. There were three major periods of production: the first and biggest was between 1860 and 1880, the second was between 1895 and 1920 and the third was between 1930 and 1945. After 1945 gold production fell continually until 1980 when the major upward adjustment in gold price led to renewed interest. There have been important new developments in each of the known gold-rich areas: Westland, Otago and Coromandel and exploration for gold in these areas and in previously unprospected regions has reached unprecedented levels.

Jan 1, 1988

While specific definitions of the main categories of mineral reserves and mineral resources are becoming well established through the efforts of the Australasian Joint Ore Reserves Committee (JORC) and the Combined Reserves International Reporting Standards Committee (CRIRSCO), there has been perhaps less attention paid to the standardisation of language used in the definition and reporting of Mineral Exploration Results and a clear understanding of the transition to Inferred Mineral Resources. This is an area of significant importance to small and medium sized enterprises in the mineral exploration sector as it represents in many cases the only tangible information by which the reader or potential investor can evaluate the future potential of such enterprises. By its very nature information in the Mineral Exploration Results category is incomplete, and frequently complex, and it is open to a broad range of interpretation by readers of various competency levels and disciplines. Many will have a short-term speculative view rather than a long-term perspective, with others out deliberately to misrepresent the information, and as such it can have an enormous impact on investment decisions if the risks associated with this information being reported are not fully understood. Authors of reports on Mineral Exploration Results, who may be Competent Persons or company directors, have to put themselves in the shoes of the reader of the report, second-guessing if you like what the reader will understand by a report, which in many cases will be of a highly technical nature. This raises reporting dilemmas and questions that require to be understood and addressed. Looking at reports on Mineral Exploration Results from the other side, readers have a degree of responsibility as well, particularly if they engage in an advisory or communications role. The tendency of commentators, journalists, analysts, and bulletin board posters to over-exaggerate the significance of a particular exploration result is all too familiar. Questions arise here as well about whether there should be more regulatory supervision and control exercised over those who use this information, all of whom greatly influence investment decisions, and many of whom have no idea there is a Reporting Code, far less an understanding of it. Examples are given and questions raised to illustrate the dilemmas surrounding the reporting of Mineral Exploration Results. In order to retain credibility with markets it is incumbent on companies to be transparent, not to be selective and to report all material information. On the other hand, information has to be taken and read in its proper context in order to avoid fuelling dramatic and unjustified company share price escalation. Timing of course is another factor that can affect the market price of shares, which may be beyond the control of those making the reports. Emotive and imprecise language, however, when reporting Mineral Exploration Results, coupled by speculation, can trigger damaging short runs on shares and destroy credibility where formerly there was long-term promise. The paper will review how Mineral Exploration Results are dealt with in various jurisdictions, and conclude that there has to be a balance between prescription and the tempering of undue optimism on the one hand, and the entrepreneurial spirit, which the industry needs, on the other.

Jan 1, 2002

The mineralogy, textures, and genetic significance of a silver-rich siderite vein and an apparently co-genetic galena vein from the South mine, Broken Hill are discussed.Both veins cut sharply across the Main Lode Horizon and appear to be coeval with thc A.B.H. Consols lode.The minerals of thc siderite vein apparently result from the preferential leaching of silver from Main Lode Horizon ore with a demonstrable "breakdown series" commencing with tetrahedrite, passing through silver sulpho-salts, and ending with simple binary compounds or with elemental silver.The siderite vein has been deposited by metahydrothermal fluids along the lines of Schneiderhohn's "secondary hydrothermal" mineralization.

Jan 1, 1968

By K Paki, K Parker, J F. Dupont

The Mount Charlotte grinding circuit at KCGMÆs Fimiston mill was recently equipped with three 650 mm CAVEX cyclones in order to improve the overflow P80, reduce the fines bypass to the underflow and improve the underflow density/recovery of water to the overflow. After the first two sets of surveys were conducted air core boosters (ACBs) were installed on the 650 mm CAVEX cyclones in an attempt to further increase their performance. JKTech was approached to assist with the examination of the data obtained from the surveys; this data was intensively modelled to determine, to a high degree of confidence, the impact the changes to the cyclones had on the classification and the benefits to the plant. This paper outlines the outcomes of the trial and the methods used to determine those outcomes.

Jan 1, 2007