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By Toivanen R-M, Leinonen O, Pekkarinen H

This paper presents developments in designing an integrated mine control system at Kemi mine. The aim of this paper is to present the general structure of the system and to outline some features of the process control strategies. The results o

Jan 1, 1998

By Boyd G. L

Stress measurement is at the core of most stability design analyses. It is demonstrated that contrary to accepted practice, it is the field measurement, and not the calculated prediction, of stress that requires most examination and review. Since it is not really possible to quantify rockmass properties, the stiffness values used in reduction of stress measurements and in subsequent design analyses (either empirical or numerical modelling) must consider an appropriate range of values.

Jan 1, 1995

Shear strength testing of rock discontinuity surfaces has been undertaken at a considerable number of open pit gold mining operations in Western Australia, as part of geotechnical studies of pit wall stability. These mining operations are located in geological settings that are typified by highly weathered and/or chemically altered rocks that contain significant structural fabric in which accurate and representative measurement of shear strength is essential.Little of the published rock discontinuity shear test work and back-analysis of failures has been conducted on weathered discontinuity surfaces, at low normal stress levels which are comparable to Western Australian conditions. Available shear strength data are reviewed and the following aspects of shear strength testing are considered:ò the need for shear strength test work and the amount of testing required;ò review of laboratory testing methods and the quality of the results; ò presentation of the test results;ò discussion of the shear strength failure criteria; ò interpretation of the test results;ò summary of test results for a variety of rock types, degree of weathering and discontinuity surface conditions;ò a review of laboratory and field shear strength data to illustrate the amount of variability that can occur; andò a monitoring strategy is proposed to manage the uncertainty associated with discontinuity shear strength.

Jan 1, 1992

By Voorhees JS, Bureau G

To operate a mine in California requires compliance with State environmental regulations, including assessment of risks and associated financial assurances for postulated worst case catastrophic event scenarios. Carson Hill Gold Mine, an open pit, heap leach operation, completed new risk assessment catastrophic event analyses in 1988. The risk assessment was performed at the same time that a new leach site (Leach Site 3) was being designed. Leach Site 3 is located about 400 m upslope of New Melones Reservoir, which is a public recreation facility and a source of drinking water. Release of leachate (pregnant solution) or ore containing cyanide and metals from Leach Site 3 into New Melones Reservoir was considered to pose the largest risk of environmental damage.Flow failure of the ore heap, potentially induced as a result of liquefaction of the saturated portion of the ore, and/or overtopping of the leach site containment embankment due to excessive precipitation were found to be the most plausible leachate release scenarios. Yearly combined probabilities of various downstream release volumes were estimated. The release volume corresponding to a yearly probability of 0.05 percent was then used to estimate potential environmental impacts and mitigation costs. The costs include earthwork to restore the geometry of the ore heap and repair the fill slope below the Leach Site 3 containment, and impacts on New Melones Reservoir.

Jan 1, 1990

By Whitham M

Prior to exploitation, the feasibility of mining and recovering ore can usually be determined to a satisfactory level of uncertainty by the consideration of conceptual scenarios, using a range of reasonable parameter values. Such values are selected on experience, knowledge of other mining operations, and the characteristics of the particular deposit being considered. Having established such feasibility, it is usually considerably more demanding to determine what the optimum set of parameters might be. Yet many decisions taken at the feasibility stage represent commitments extending at least into the medium term.

Jan 1, 1991

The Big Bend and Cobra molybdenum prospects which occur near the margin of the Karamea Batholith in the Northwest Nelson molybdenum province are compared. The Big Bend Prospect is a 3000 m by 800 m area of disseminated pyrite and anomalous molybdenum associated with Cretaceous porphyry intrusives and later argillic and potassic alteration within Ordovician schists and phyllites adjacent to the batholith margin. The Cobra Prospect is a 1200 m by 1200 m area of weakly disseminated pyrite mineralisation and anomalous molybdenum-in-rock associated with moderate to strong quartz-molybdenite and quartz-orthoclase-molybdenite veining in quartzite.

Jan 1, 1979

By Urabe T

In June 1989 a diving cruise of the French submersible Nautile has been carried out on the North Fiji basin spreading ridge. The objective of the cruise was the geological and geochemical study of the active spreading axis and associated hydrothermalism processes. This operation was the third cruise of the French-Japanese STARMER project following two cruises of the R/V Kaiyo in 1987 and 1988.INTRODUCTIONAfter the Seapso III cruise (Auzende et al., 1986, 1988a and b) of the R/V Jean Charcot in 1985, the objective of the Kaiyo 87 and 88 cruises was the complementary Seabeam mapping of the North Fiji Basin spreading axis between WS and 22'S and a systematic sampling (water and rocks) and deep towing (TV and photos) at about every ten milles along the axis.

Jan 1, 1990

By J Aitchison, G Clarke

A reappraisal of the stratigraphy, new regional kinematic analysis and thermobarometric data allow a new interpretation of the metamorphic zoning and tectonic structure of the Upper Eocene high-pressure metamorphic core complex of northernNew Caledonia allow a three steps evolution to be proposed: 1. subduction and understacking of previously thinned continental crust elements; 2. subduction blocking due to the crustal thickening; and 3. crustal thinning and extensional detachment during the diapir-like uplift and unroofing of the eclogitic core. Steps 2 and 3 may be partly contemporaneous. Such a model accounts for the thermobarometric and radiochronologic data, and also for the weakness of substratum deformation during the emplacement of the ophiolitic nappe

Jan 1, 1995

By Dobos SK

The Black Ridge Gold Deposit is located in the northern part of the Clermont Goldfield, which is situated at the boundary of the Bowen Basin and Anakie Inlier, Queensland. The goldfield comprises a series of NNW-trending semi-isolated basins, which are tectonically aligned with the Denison Trough, the west-most division of the Bowen Basin (Fig. 1-1).The main stratigraphic units in the deposits in younging sequence are the Anakie Metamorphics, the early Permian Blair Athol Coal Measures, the late Permian(?) White Section, and the Tertiary basalts which are regionally widespread, and intruded by abundant mafic and felsic plugs.

Jan 1, 1990

By Dunn J, Nguyen G, Graham J

A pyritic gold concentrate from the Golden Mile, Kalgoorlie, was roasted over a range of temperatures in a pilot scale fluid bed reactor. The calcines were subsequently cyanide leached. Mineralogical studies of the con- centrate, calcines and leached residues were also undertaken. Calcines produced at 500'C gave the poorest gold extractions and high cyanide consumptions. Gold recoveries of approximately 90 per cent were obtained from calcines produced at 550-600'C but higher roasting tempera- tures resulted in an increase in the residual gold content of the leached calcine. There is some evidence of flash smelting of the pyrite at the higher roasting temperatures and encapsulation of gold particles. Mineralogical examination of the calcines shows that the mechanism of oxidation is temperature dependent. At 500'C pyrite is directly oxidized to hematite with a concentric layered texture which appears to inhibit lixiviant access to enclosed gold particles. At higher temperatures the conversion sequence pyrite-pyrrhotite-hematite produces a spongy calcine which al- lows easier penetration by the leaching medium.

Jan 1, 1991

The mining of Australia's rich and diverse mineral resources has been central to the development of the continent by "Europeans" over the past two hundred years. Mining has historically been encouraged (to varying degrees) by development-orientated state governments (the. managers of largely Crown-owned resources) and since Federation, by successive Com- monwealth governments (which have seen mineral development as a means of generating export revenue to fund predominantly social-welfare orien- tated budgets). This marriage of convenience between governments and the mining industry has to date served all parties well. However, Australia's entry to a new world economic environment at a time that community percep- tions are changing (owing to an education-inspired challenge to "old" values) is challenging the hitherto held assumption that mining develop- ment is always aligned with the well-being of the State and community. Issues such as the type and extent of State/Commonwealth government taxation, resource ownership and control, the environment, land use con- flict, the extent and desirability of secondary processing and infrastruc- ture funding are being debated in the public arena. Opponents of mining in the community are well-organised and are well funded, articulate and more importantly, they have effective communication channels with most governments, irrespective of political complexion. Apart from some television-orientated corporate image building and recent efforts by AMIC, the industry's response to this challenge has been unco-ordinated, poorly directed and arguably ineffective. Professionals working in the industry are concerned about the community's perception of themselves and their industry. Recognizing that the Australian democratic system ensures that, in the large, government at its various levels, is reflective of and responsive to the views and aspirations of people, the industry's response must be wide- ranging, equally articulate and couched in a form which is politically acceptable. New objectives in providing information to the public and its educators must be formulated. Moreover, professionals are looking for new directions from industry leaders. The Institute is well placed to facilitate this process.

Jan 1, 1988

What is `environmental risk'? There are two possible perspectives: (a) The risk that mining activity will have an impact on the environment. (b) The risk that due to a perceived impact on the environment, the mining activity is at risk due to some legal consequence. This paper is concerned with the second of these perspectives, and particularly with the way in which mining companies can manage that risk. Environmental risk - possible legal consequences The risk is that the mining operation will be disrupted. Disruption may be: (a) Physical. The mining activity can be stopped, altered, or modified, or something additional can be required to be done. (b) Financial. Penalties (up to $1M) on corporations and in some states on both directors and managers. Land may also be included on a contaminated land register (significant impact on asset valuation).

Jan 1, 1994

By Ride G

The provision of a water supply is a major consideration in planning mining developments particularly in remote areas. The evaluation and development of adequate water supplies in and areas of Australia is often as important as the discovery of the orebody. The copper orebody at Warrego near Tennant Creek could not be mined economically if cheap treatment water was not available near the mine. This paper describes the difficulties in obtaining water in the Tennant Creek area and the water supply investigations carried out near the Warrego Mine which resulted in the successful discovery and evaluation of a reliable large scale water supply. It is contended that the establishment of a water supply must be approached on a systematic and scientific basis similar to the approach with the exploration and establishment of actual ore reserves. Mining companies with similar water supply problems may benefit by approaching their problem on this basis. The approach adopted by Peko Mines is outlined in this report.

Jan 1, 1980

By Chen Z, Dong H

This paper describes the autogenous carrier flotation of 0 - 20 ¦m ilmenite using 40 -- 80 }tm ilmenite as carrier. Investigation is made of the influence of main technological parameters on autogenous carrier flotation. The mechanism of autogenous carrier flotation is discussed using extended DLVO theory. The main conclusions are as follows: 1. the smaller the fine particles the more easily they adhere.to carriers; 2. the selectivity of autogenous carrier flotation depends on the selectivity of adsorption of collector. In the autogenous carrier flotation of ilmenite/plagioclase mixture assaying 15.35 per cent TiO2, a concentrate containing 47.17 per cent Ti02 can be obtained by primary separation with a recovery of 93.05 per cent. KEYWORDS: Autogenous carrier flotation, extended DLVO theory, ilmenite, styrylphosphonic acid.

Jan 1, 1993

The Mt Leyshon Volcanic Complex lies 24 kilometres south-west of Charters Towers and is part of a major continental volcano-plutonic province of Permo-Carboniferous age in north-east Queensland.The volcanic complex is located on the contact between Cape River Beds of Cambrian age and the Ordovician Ravenswood Granodiorite Complex. The emplacement of the complex appears to have been structurally controlled and is at the intersection of major north-east and minor north-west trending lineaments. The gold mineralisation occurs in the form of cavity coatings, matrix replacement, disseminations, and vein and fracture fillings containing quartz, chlorite, carbonate, pyrite, sphalerite, chalcopyrite and galena in various volcanic breccias and rhyolitic intrusives. The current published mineable ore reserves, calculated by Noranda Australia Limited, are 6.3 million tonnes of 1.8 grams per tonne gold and 4.8 grams per tonne silver. The orebody is open at depth, and in all directions except north where it abuts the granodiorite.

Jan 1, 1986

By Richards JR, Herbert HK

A basic question in preparing this review was how to define sulphur mineral occurrences as being associated with the Pacific Rim. This question will be reconsidered later. The isotope composition of sulphur- containing minerals may be considered in terms of two primary sources - 1. deep- seated sulphur, devoid of crustal contam- ination with a 634S value near 00/0o and 2. oceanic sulphate which fluctuated in value between +10 and +300/00 over geological time (Claypool et al., 1980). However, minerals have seldom been directly derived from these primary sources as even evaporites have been dissolved and reprecipitated. The marine source is differentiated biochemically and isotopically in recent sediments where sulphide from bacterial sulphate reduction may be significantly depleted in 31S. The question of chemical interaction of ascend- ing magma with upper crustal rocks has become one of degree rather than whether or not it occurs. Mineral deposition is considered increasingly in terms of mixing of fluids and their chemical reactions with rocks rather than direct precipitation from magmas or hydrothermal fluids derived from them.

Jan 1, 1987

By J C. Small

Time-dependent deformation occurs when geo-materials are under an applied load; this may lead to additional deflection of a tunnel structure and the stress redistribution in the surrounding rock, shotcrete lining and rock bolt support system over time. A better understanding of this creep behaviour can improve the reliability of design, construction and maintenance of tunnels. Hence, the present investigation was carried out on the time-dependent properties of rock, shotcrete and the combined tunnel support system. Tunnels constructed in different ground conditions were modelled. The closure changes of the tunnel with time and the redistribution of stress in the surrounding rock, shotcrete lining and rock bolts due to the creep deformation were analysed. Results of the present analysis were compared with the results from the commercial program ABAQUS.

Jan 1, 2008

From August 1962 to June 1976 Peko Mines Ltd. produced Gold Bullion at the Peko Control Mill using 18x24 Denver Mineral Jigs and strake tables. Gold ores treated during this period were obtained from Orlando, Juno and Ivanhoe Mines and from the Warrego Mine after 1974, all in the Tennant Creek Area of the Northern Territory. With the downturn in copper prices Warrego Copper ore mining ceased and the copper Smelter closed down in February 1974, Warrego gold ore continued to be treated in the Peko Concentrator.

Jan 1, 1978

By T Baumgartl, M Edraki, L Huang, D R. Mulligan

"Phytostabilisation with tolerant plant species has been advocated as a cost-effective solution for sustainable cover of tailings from metal mines and bauxite refinery. The development of sustainable plant ecosystems on such wastes requires not only tolerant plant species compatible with local climatic conditions, but also the formation of stable and functional root zones through systematic processes to develop functional soil matrix and horizons (eg A-B-C). However, the process requirements for reconstructing functional root zones in tailings are poorly understood. Based on a review of current literature and industry experience in tailings revegetation, the present paper conceptualises three key phases in the process of root zone development in amended tailings: hydro-geochemical stabilisation resulting from the interactions among tailings characteristics, amendment measures and local climatic conditions the rehabilitation of soil biological capacity the establishment of ecological (carbon and nutrient) linkages between the rehabilitated root zones and the above ground plant communities.Key research is required on: the relationship between hydro-geochemical stability and mineralogy and geochemistry of tailings, in response to rehabilitation treatments under local climatic conditions the relationship between soil biological capacity and hydro-geochemical stability in the root zone the transition of soil microbial communities specific to exogenous organic matters into those required for mineralising litters of in situ plant communities.CITATION:Huang, L, Baumgartl, T, Edraki, M and Mulligan, D R, 2012. Sustainable phytostabilisation of mine tailings - A critical analysis of system requirements and approaches, in Proceedings Life-of-Mine 2012, pp 105-116 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 10, 2012

By Mitchell M. A

The steeply dipping Mammoth orebody is mined by Gunpowder Copper Limited using a sub- level uphole bench stoping method at a mining rate of 350 000 tonnes per year. of three per cent copper ore. Access to the mine, is provided by 1 in 9 decline which spirals in the footwall connect-, ing all the sublevels, thus maximising mobility and accessibility of trackless mining equipment Sublevels are driven in ore off cross- cuts from the decline every 15 metres vertic- ally. Sublevel drives are stripped out to widths up to 18 metres before cutoff slots are mined at each end. A two boom fan drilling jumbo is used to drill inclined rows of holes to the floor of the sublevel above. Two or three rows are fired at a time which allows broken ore and remnants from the level above to be mucked out by rubber tyred LHD equipment to the brow. Ore widths of up to 80 metres are en- countered at lower levels where ring drilling from longitudinal drill drives will break ore to a draw point system below. Development is carried out with three boom rubber tyred jumbos. All haulage from the mine is in 20 and 35 tonne rear dump trucks. All aspects of the mining operation are discussed including ventilation, pumping and drainage, services and future planning.

Jan 1, 1974