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Amongst the Pacific Rim countries, Papua New Guinea (PNG) is the leader in new gold discoveries and developments leading to new production. PNG has shown a dramatic increase in gold production when taken from a base of about 600 000 ounces in 1984 to 1 160 000 ounces in 1986. 1987 is expected to produce about 1 500 000 ounces and new planned developments will give further large increases. PNG's leading position when compared with neighboring Pacific Rim countries is only partly due to its favorable geological setting along the "Rim of Fire" epithermal zone. More important have been well-thought-out mining development legislation and good administration as well as consistent taxation and royalty policies. A stable political environment and a track record of new mining developments over the last 15 years, both pre and post Independence in 1975, have also been important factors in encouraging the new developments. Early Portuguese explorers associated the New Guinea mainland with gold as early as 1525 but it was not un,11 1R77 that a small ill-fated gold rush gave the first recorded production at Laloki near Port Moresby. Modest but commercial discoveries were made in the outer islands and coastal mainland regions from 1888 to 1926. In 1922 William "Sharkeye" Park found gold at Edie Creek and this led to major discoveries at Wau and Bulolo which were the first large scale commercial gold Operations.

Jan 1, 1987

By Morrison R. D, Davis J. J, Fraser B, Kojovic T

1991 saw the completion of a three-year $1.1 million research and development program in mineral sands beneficiation, funded in two associated projects by the Australian mineral sands industry through AMIRA, and carried out by the Julius Kruttschnitt Mineral Research Centre. It is believed to be the largest R&D project in mineral sands ever conducted by a university research group. It covered dry plant operation, and delivered several products to the industrial sponsors, including: ò A detailed characterisation of the radiation properties, mineralogy and size distribution of inhaleable dust arising in dry plants. ò New process models of magnetic and electrostatic separators. ò New on-line instruments for elemental assay (in association with AMDEL) and bulk conductivity measurements of dry process streams. ò Demonstration and evaluation of the Magstream magnetohydrostatic separation technology.

Jan 1, 1992

The geographical region of South East Asia is variously defined, but generally agreed to include the Asean group - Philippines, Malaysia, Thailand, Singapore and Indonesia. Other regional countries, such as Vietnam, Laos, Burma, Kampuchea etc. are of course geographically part of the region, however in economic terms, they play a minor role. It is the Asean group that dominates present economic activity and provides the overwhelming opportunity for commercial development. My experience in South East Asia has been gleaned over 15 years of regular travel in the region. More recently, we have established company offices in Malaysia, Singapore and Indonesia to extend and deepen contacts with major customers. This progressive development is an integral part of a planned growth pattern and will be discussed in more detail shortly. South East Asia is a rapidly developing economic growth centre, a fact which is clearly recognised and accepted by most commentators. An important question is then to be asked: Why has the region been relatively neglected by Australian, U.S. and European industrial supply companies? I will attempt to address this question in the context of industrial minerals and propose some ideas as to how effective sales programs could be developed. Firstly, let's consider the market potential provided by countries within the region. It is reasonable to suggest that industrial growth in S.E. Asia over the past 20 years has been generally steady and in some cases, explosive. Until recently, this growth has predominantly been driven by development of internal (regional) demand. Population growth and rising living standards have ensured that basic industries have enjoyed a solid uptrend in sales and production. The industries which most benefitted from regional economic development over this period were, interestingly, those which we understand to be major users of industrial minerals - glass, ceramics, paper, surface coatings, cement, refractories, rubber and plastics. Each of these industrial sectors has been influenced by different growth stimulii over a 20 year period. Nevertheless, they also enjoy a common feature which ensured an above average performance. All sectors are fundamental to an environment enjoying rising living standards and rapid growth in general prosperity. More recently, internal growth factors have been overtaken by a recognition that manufactured products from the region are competitive in export markets. This comparatively recent development provides the most interesting possibilities for higher value industrial mineral raw materials. Let me explain: For 20 years, industrial growth in South Asia has essentially been focused on satisfying domestic demand. Finished quality of manufactured items was orientated to a developing market more interested in cost than aesthetics or long life. This was reflected in raw material specifications, which often did not exist and at the best were undemanding.

Jan 1, 1989

By Gillies A. D S

A device has been developed for modelling the behaviour of coal under conditions which may lead to spontaneous combustion. It is designed to model the behaviour of a stockpile of large mass. The apparatus can test coal samples taken from the flow stream from mine through washing, stockpiling and transportation to the point of utilisation. It tests samples in an as received' condition and so takes into account the effect of aspects such as particle size and moisture content on propensity for spontaneous combustion to occur. Results of the preliminary tests undertaken are given and future applications of the apparatus are Discussed.

Jan 1, 1995

By K Lee, K Fernando, S Rayner

Copper-gold ores have been technically difficult and uneconomical to process due to high consumptions of cyanide. Many copper oxide and sulphide minerals react with cyanide to form copper cyanide complexes, partly contributing to the high level of weak-acid dissociable cyanide in the tailings which is normally experienced during the processing of copper-gold ores. The cost for detoxification, if required for treating these tailings, would further inhibit the development of these copper-gold resources unless the cyanide used for leaching was recovered. Several technologies have been proposed to process copper-gold ores, aiming to recover copper as a co-product and cyanide for recycling in conjunction with the leaching process. A critical review of these processes reveals that a pre-concentration stage (solvent extraction or resin ion exchange) is required. Cyanide is recovered by the conventional Acidification-Volatilisation-Regeneration technique in most cases. A critical evaluation is also provided on technical aspects related to the use of Vitrokele Technology and a newly developed Elutech process in processing copper-gold ores, in particular with its application at May Day Mine.

Jan 1, 2000

By Singh JK, Singh R

With a view to producing increased target output every year, Indian coal mining industry is fast moving towards mechanisation but the present approach of mechanisation suffers from lack of standardisation, mainly due to nonavailability of the cutting data for various machine/rock combinations. The coal seams of the country are relatively hard in nature and the coaling machines are reported to be affecting production and productivity of the coal mine and the very trend of niechanisation. This paper presents the result of extensive study performed to visualise the cutting characteristics of coal seams of compressive strength ranging from 20 MPa to 65 NIPa. In a specially designed drag bit type coal plough rig, continuous recording of cutting forces was done with the help of a microprocessor based data logger and the specific energy of cuttability was evaluated at different depth of cut and speed of cutting. The geomechanical properties such as compressive strength, orientation and frequency of cleats etc. and different indices of coal seams were measured in the laboratory and field and relationship was developed for easy determination of specific energy.

Jan 1, 1992

By Scott IA, Jefferson C, Dipasquale S

This paper describes the use of modelling and simulation techniques in the analysis of the heavy medium plant at the Lead/Zinc Concentrator of Mount Isa Mines Limited. The objective of the study is to determine how to increase heavy medium plant recovery at a higher than current rejection rate in order to achieve the desired throughput through the grinding and flotation sections of the concentrator. Three options were considered: 1. Install smaller aperture preparation on screen to enable the cyclones to be fed finer materials. Install smaller diameter cyclones. 3. Maintain low viscosity medium.

Jan 1, 1987

By Anderson JDC

Opencast Lignite Mining requires topwall strata of seams to be fully depleted and footwall aquifers sufficiently depressurized. To prevent a spread of the cone of depression into protected wetlands some distance away, alternatives had been investigated such as closing water works, underground slurry wall barriers and recharge by infiltration. As a result of these investigations, the infiltration method has been chosen and in a first phase during the next decade it will utilize as much as 55 x 106 m3/year. Using this approach, the survival of the wet lands is assured.

Jan 1, 1988

The mmmg operations carried out by North Broken Hill Limited, necessitate the use of four shafts for the haulage of ore, men, and supplies. These are:-1. Blackwood's Shaft.-British Section, which has 100 feet intervals between levels to the bottom 800 feet level plat;2. Thompson's Shaft.-British Section, which has 100 feet intervals between levels to the bottom 1400 feet level plat;3. No. 1 Shaft.-With intervals between levels:(a) 100 feet to the 800 feet level,(b) 150 feet from 800 feet level to the 1700 feet level;4. No. {2 Shaft.-2770 feet from collar to bottom plat, with intervals between levels: (a) 100 feet to 800 feet level, (b) 150 feet from 800 feet level to the 2600 feet level. (c) 170 feet from 2600 feet level to the 2770 feet level.All shafts have two cage compartments, and the No. 2 Shaft a skip installation in addition.For the control of hoisting operations an electric signalling system is installed on each shaft, and is supplemented by a counterbalanced rope pull ("Knocker line") operating a surface gong. The latter system is shown diagrammatically in Fig. 1.Two sets of electrical equipment are used per shaft. The first, shown in Fig. 2, is that operated by the braceman or...

Jan 1, 1940

THOSE who dabble in m.ining are no exception to the general rule that persons who know a little of a subject are apt to think that they know all about it. Some colour may be lent to the belief that anyone may succeed in mining when we hear stories ofsuccessful diggers and others who have accidentally dropped on to something good through no foresight on their part; but we seldom hear the contra account of the far larger number who fail. Those who go more thoroughly into the subject, and take up mining as a profession, know very well that it is not one that can be carried out successfully by rule of thumb, but when they point this out to the public they are credited with trying to make it a closed profession; and outsiders are for ever trying to find out the 'trade secrets,' at the same time spurning the main one, which is hard study, experience, and the ability to apply their knowledge.The average mining man is not rich. When he amasses a fortune it is generally through speculation rather than professional work, thought no doubt his technical knowledge may have assisted him. However, making a fortune and running a mine are twodifferent things.

Jan 1, 1911

By Javad Koleini S M

The sources of arsenic compounds vary from As(lll) oxide produced from roasters to wastes containing arsenic from chemical or mineral processing plants. The removal of arsenic via co-precipitation with iron is currently proposed as an acce

Jan 1, 1994

By G Bignall, I Chambefort, A B. Christie, A J. Rae, M P. Simpson

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Key indicator hydrothermal alteration minerals formed from fluids of known fluid composition (neutral versus acid pH) and temperature have been mapped for New Zealand (NZ) geothermal fields by visible/near-infrared (VNIR) and short wave infrared (SWIR) reflectance spectroscopy. Smectite, interstratified illite-smectite and illite formed from neutral pH fluids have zoned distributions with higher temperature illite (>220ºC) in and around the upflow of chloride waters and low temperature smectite (<150ºC) on the margins (eg Ohaaki, NZ). In adularia-sericite epithermal deposits, Au-Ag veins are similarly surrounded by zoned clays, with mineralised veins enclosed by illite (eg Martha, NZ) or occurring at the illite/illite-smectite boundary (eg Favona, NZ). Reflectance spectroscopy is also highly effective in identifying minerals formed from acid fluids; both steam-heated acid-sulfate waters (eg kaolinite and alunite at Rotokawa, NZ), or magmatic-hydrothermal fluids (eg pyrophyllite and topaz at Ngatamariki, NZ). These same alteration minerals commonly show zoned distributions in high sulfidation epithermal deposits (eg Rodalquilar, Spain) and in lithocaps associated with porphyry deposits (eg Lepanto, Philippines). Thus reflectance spectroscopy permits the rapid identification of key alteration minerals that can be mapped at a high sample frequency and used as vectors towards mineralisation.CITATION:Simpson, M P, Bignall, G, Rae, A J, Christie, A B and Chambefort, I, 2015. Mapping hydrothermal minerals in New Zealand geothermal fields using reflectance spectroscopy (VNIR-SWIR) and application to mineral deposit exploration , in Proceedings PACRIM 2015 Congress, pp 243–248 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Basillo CI

The adsorption mechanisms of various thiol collectors can be subdivided into four classes: chemisorption, EC-mechanism, catalytic oxidation and metathetical substitution. The chemisorption mechanism occurs at potentials below the thermodynamic potentials for the metal-thiol compound formation and is reversible. The EC-mechanism occurs when the mineral is sufficiently oxidised to liberate metal ions to form metal-xanthates; therefore, it is observed with more easily oxidisable minerals and/or with collectors having large pK values. Thionocarbamates adsorb on sulphide minerals via the EC-mechanism due to their large pK values. Although the adsorption occurs at very low potentials as compared to xanthates, it is irreversible with large overpotentials. On the other hand, the adsorption of modified thiophosphates and thiophosphinates occurs near the thermodynamic potentials because of the low pK values. The metathetical substitution is believed to occur only when a mineral is highly oxidised. These classifications are useful for studying the effects of electrochemical potentials and the molecular structure on the collector adsorption Mechanisms.

Jan 1, 1993

By Lightfoot BW, Bultitude-Paull J

The Sirosmelt top submerged lancing system has many applications in the smelting of base metal and complex materials. It has particular advantages for smaller scale smelting and the treatment of recycle materials in smelters where its low capital and operating costs and its operational flexibility are of immediate benefit. The system can be fueled by oil, gas or coal, as well as by mixtures of fuels. For many applications, the use of coal as a fuel has operating cost advantages over oil and gas, but conventional pulverised coal feeding systems entail very large capital expenditure and this militates against the use of coal. The methods available for improving on conventional technology for coal firing of Sirosmelt systems are discussed and operating experience with alternative systems are outlined. The use of coal as a reductant in the Sirosmelt system is also discussed.

Jan 1, 1987

By Estoque J, Abaigar J, Domingo B, Acenas M

The Siana gold-silver deposit of Surigao del Norte, Mindanao, Philippines is perhaps one of the most complex in the world, being related to an ancient suture zone known as the Philippine Fault. Early accounts described the deposit as epithermal, consisting of an upper limestone replacement orebody and a lower vein type deposit hosted in andesite. Recent field and laboratory studies, in correlation with the latest findings on the archipelago's tectonic evolution, however, led to the present interpretation of the Siana ore deposit's origin as involving both syngenetic and epigenetic processes, with limestone breccia, similar to the Cow Head Breccia of Newfoundland, as the principal host to mineralization.

Jan 1, 1987

An efficient stores organisation is essential for an efficient undertaking. Unless the stores organisation is able to meet the requirements of its requisitioners promptly and economically, the undertaking as a whole cannot function efficiently.Delays or errors in supply of material, or substitution due to lack of material availability from the stores are costly and must be eliminated. This then makes the objective of a store, to supply on demand at the cheapest possible price, those items of stock which it is organised to carry, also to procure as quickly as possible and at the lowest price those special items required which are not normally carried in stock. To do this it is necessary to set up a stores organisation consistent with the size and requirements of the undertaking. Stores organisations vary with the nature of the undertaking they are designed to serve. In the case of the Broken Hill Associated Smelters Pty. Ltd., an organisation has been established to meet the operating and maintenance requirements of the Port Pirie Works. These embrace the particularly wide range 0:1; activities associated with roasting" blast furnacing and refining the lead concentrates from the Broken Hill Mines in a continuous metallurgical process producing a variety of refined metals; also many associated activities including power production and engineering maintenance and construction.

Jan 1, 1951

The prime requirement is market, which for NZ inevitably means overseas markets. In order to be internationally competitive, the economies of scale and mechanical handling are essential. Since significant markets have not been sought, the full extent of our industrial mineral potential is not known. In general the technology exists to impart the desired quality, but at a price. Price is the main constraint, which may confine truly competitive operations to coastal situations to avoid high internal freight charges. Some commercial deposits of construction materials are being sterilised by zoning, making the costs to the consumer and country unnecessarily high. Unless management is enlightened and marketing is forceful, it can restrict growth. There is a good case to mount a search for phosphate minerals. The main growth areas are likely to be direct shipping ores like limestone, silica sand, and olivine, but in particular pumice.

Jan 1, 1978

By G C. Lukey, J S. J van Deventer

The disposal and subsequent encapsulation of mine tailings in a cost-effective and environmentally secure and responsible manner is one of the principal issues facing any modern mining project. A careful assessment of all options available for the capping and subsequent remediation of tailings is important because it can result in large capital, operating and closure cost-savings. For these reasons, the technology of geopolymerisation is receiving increasing attention for the stabilisation and solidification of waste materials produced from mining operations. The first part of the current study investigates the application of geopolymer technology to the capping of hypersaline mine tailings. It has been found that suitable geopolymeric materials which have satisfactory compressive strength, durability as well as low permeability, can be formed using between 60 - 75 per cent of mine tailings as the main ingredient. It has been established that geopolymeric materials have the ability to suppress dust generation and prevent salt precipitation on the surface of the mine tailings. The slurry-like consistency of geopolymers would promote efficient application procedures through established tailings disposal techniques. This is a possible close-out technique for hypersaline tailings storage facilities such as those commonly found in Western Australia, which meets both regulatory requirements and community expectations. The immobilisation of contaminant metals within geopolymers has been investigated in the second part of the present study. In particular, the leaching characteristics of Cu and Pb from geopolymeric matrices derived from different fly ash sources have been examined. Potential breakdown of each geopolymer containing metal contaminants due to the leaching of Si and Al from the geopolymeric matrix has also been investigated.

Jan 1, 2000

By G Senanayake, J Andreazza

The general experience in gold cyanidation research activities and plant practice is that high oxygen and cyanide concentrations improve gold leaching kinetics which in turn reduce residence time and increase throughput. This paper shows how the improved pre-oxidation method for the pyrrhotite rich gold ore of Bounty Gold Mine has increased gold recoveries at lower reagent consumption rates. The installation of a pipe reactor, in conjunction with a Multi Mix Systems oxygen injector, has lowered the amount of oxygen required to achieve a dissolved oxygen level target of 20 mg/L. The improvement of the pre-oxidation stage and lead nitrate solution addition has led to a reduction in the free cyanide concentration required for leaching, resulting in a decrease in cyanide consumption rate by 36 per cent to achieve a one to two per cent improvement in the gold recovery.

Jan 1, 2002

This paper reviews the various processes successfully in operation to treat refractory gold ores and describes in detail the alkaline pressure oxidation circuit operating at the Barrick Mercur Mine, Utah, U.S.A., on car- bonaceous/sulphide refractory ore and the acidic pressure oxidation circuit operating at the Barrick Goldstrike Mine, near Carlin, Nevada, U.S.A., on sulphide refractory ore. The autoclave process is important to Barrick for the extraction of gold. The Company has operated successfully a 750 ton per day unit at its Mercur property for the past two years and more recently has commissioned a 1500 ton per day unit at Goldstrike. The paper presents data relative to operating costs, materials of construc- tion for autoclaves and peripheral equipment, reagent requirements, and changes required during commissioning for both autoclave systems.

Jan 1, 1991