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By R Balusu

This paper provides an overview of computational fluid dynamics (CFD) modelling capability developed by CSIRO with the aim of improving the knowledge of flow migration dynamics within longwall goaf areas. The CFD models can be used to study the ingress of oxygen into the goaf in different ventilation scenarios and goaf drainage arrangements. This approach not only helps the design of effective gas control strategies but also the management of spontaneous combustion risk in the goaf. Innovative goaf inertisation strategies have been developed and implemented during longwall sealing operations. Work is continuing to develop general guidelines of proactive goaf inertisation strategies to suppress the development of spontaneous heating behind active longwall faces.

Jan 1, 2005

By Le V, Nguyen Ngoc Quynh, R H. Murfitt

The Truong Son Fold belt in Indochina hosts the significant Sepon gold-copper district (Laos) and the similar gold-basemetal districts of Phuoc Son and Bong Mieu (Vietnam). With over seven years of exploration, Toronto-listed Olympus Pacific Minerals Inc, is one of few foreign companies that have to date made a substantial investment in mineral exploration in Vietnam.Much of this work has been conducted along the Phuoc Son û Tam Ky Suture, on the south-eastern limb of the Truong Son Fold belt on the Vietnamese side of the border with Laos. These programs have produced a significant number of gold prospects at varying stages of exploration development. The Phuoc Son û Tam Ky Suture is a major Paleozoic subduction zone that extends from northern Laos, through Central Vietnam and out into the South China Sea.It represents a Lower Mesozoic collision zone between the Paleozoic-age Truong Son fold-belt terrain to the north, with the crystalline terrain of the Pre-Cambrian Kontum Block to the south. Since its formation, it has been a locus of deep faulting, continental accretion, intensive intrusive activity and mineralisation. This paper briefly discusses the geological setting, structure, metamorphism, mineralisation, exploration history, and proposed mining development of the Olympus Phuoc Son Gold Project, with particular reference to the Phuoc Son û Tam Ky suture.

Jan 1, 2004

By Hall C. E, Chrisholm J. M

Resource calculations for shear hosted deposits of any type are difficult regardless of which calculation technique is used. One of the main problems is the determination of the geometry of the mineralisation. Once this has been elucidated then the appropriate resource calculation methodology can be employed with a search distance and orientation that is relevant.

Jan 1, 1993

Any engineering firm hoping to do business in the modern world must understand-and take into account-the social and economic realities of client, country, culture, and community. If these considerations are ignored, any large-scale international development project is doomed to failure even before it begins. In this changing world, the distinctions between `developed', `developing', and `less developed' nations are more and more blurred. The so-called `less-developed' and `developing' nations are rapidly acquiring technology, an educated man- agerial and technical class, manufacturing capa- bilities, a growing spectrum of developed financial and raw materials resources, and a broad range of labour skills. These nations are establishing themselves as an integral part of the modern world, on an equal footing with other nations and with justifiable expectations for an ever higher standard of living and an ever better quality of Life.

Jan 1, 1978

By Kidman B. E

The Fitzpatrick area is the deepest section of the North Mine, with the orebody located between 1450 and 1800 m below the surface and some 600 m NE of the main No. 3 Shaft orebody and separated from it by the intensely sheared Globe Vauxhall Shear Zone. Development towards the Fitzpatrick area commenced in 1977 after earlier initial exploration drive development. However, it was not until 1982 that mining in the Fitzpatrick area actually began with the silling out of No. 36 level at a depth of some 1600 in. Since that time mechanised cut and fill mining from an incline ramp system with connecting stope accesses has progressed some 25 m above No. 36 level. Initial sill development on No. 37 level at 1660 m depth also commenced in July 1987 to further develop the Fitzpatrick area.

Jan 1, 1988

By Beeforth C. G

The use of Non-Linear Programming to obtain improved schedules of future activity in two specific cases of mining and treatment of minerals is described. The two cases were (i) reclamation of gold, uranium and sulphur from old surface tailings dams and, (ii) underground mining of gold. The method used an augmented Lagrangian device to reduce a constrained Non-Linear Programme to a sequence of unconstrained hill- climbing procedures. The main advantages of the method appear to be those of (a)flexibility of modelling of industrial characteristics and constraints and, (b) reasonably modest computation times.

Jan 1, 1977

DR. WARK, said: I have not come to Broken Hill to tell you how to conduct flotation operations; indeed, during my short stay here I have already learned much concerning the process, of the many difficulties which have been overcome, and of those still awaiting solution. My purpose to-night is rather different. All who have been concerned with the operation...

Jan 1, 1933

During October 1947 an Authority to Prospect was granted by the Minister of Mines to lVIount Isa Mines Limited over an area of approximately 75 sq. miles to the north of Mount Isa.Application for the Authority to Prospect had been made after Zinc Corporation Limited had been granted prospecting rights over two areas, one of 1,265 acres immediately to the north of the Mount Isa Mines leases and the other of 1,960 acres adjoining the south end of Mount Isa Mines leases.METHODSAs a means of providing a cheap map of sufficient accuracy on which to plot geological features, both Mount Isa Mines Limited and Zinc Corporation Limited agreed upon aerial photographs and the two companies shared the cost of an aerial photographic survey by Adastra Airways of 130 sq. miles which covered the prospecting areas held by both companies.The photographs were on a scale of 800 ft. to I in. with 60% overlap on the north-south runs and 25% overlap east-west. A set of alternate prints enlarged to 400 ft. to 1 \in. were obtained for field work. The 400 ft. to 1 in. scale unglossed photographs (size 18 in. x 18 in.) were taken On to the field and rock outcrops, and uncorrelated structures were plotted directly on to them in red crayon pencil. The geological observations were then transferred in the office to a tracing on which accuracy of azimuth and scale was controlled by use of a photo mosaic and ground surveys.

Jan 1, 1953

Mineralisation adjacent to Herberton occurs within three main subcentres. The Her- berton Hill subcentre is characterised by the association of Sn,W the Herberton Dividing Range South subcentre by Sn, and the Herberton Dividing Range North by Cu, As. The relation- ships between the subcentres are discussed in terms of metal distribution, production, deposit types, wall rock alteration and re- lationships with granitoid intrusives. The temporal and three dimensional spatial re- lationships between the centres are uncertain.

Jan 1, 1978

By Wang QP, Quan YH

Mechanical models are established in accordance with the degree of mining on both sides of the coal pillar, and formulae were derived which calculated the superposition stress distribution and the width of the plastic region. The stability of the coal pillar was analysed and a reasonable size of coal pillar determined, in accordance with the elastic region rate. Further practical examples for the stability of the coal pillar are calculated and simulated.

Jan 1, 1992

The role and policies of the Aboriginal Sacred Sites Protection Authority are described in conjunction with the provisions of the N.T Aboriginal Sacred Sites Act 1978. Comment is made on the application of the legislation and these policies to development proposals in the Northern Territory. A brief review of criticisms by both developers and Land Councils is provided together with responses to these Criticisms.

Jan 1, 1984

By Kyle J. H, Misra V. N

The recovery of copper from a flotation concentrate using ferric chloride leaching has been investigated. The concentrate from the Horseshoe Lights Mine near Meekatharra, Western Australia, contained mainly digenite, pyrite and talc minerals. Over 95 per cent of the copper was dissolved in an acidified ferric chloride solution in one hour at 70¦C and ambient pressure. The pyrite and gangue minerals did not react. The leaching process was found to consist of four separate reactions and the shrinking core model was used to describe the process. The effects of particle size, temperature, concentration of FeCls, stirring speed and leaching time on metal dissolution were investigated. The apparent activation energies in the second, third and fourth reactions of leaching of copper concentrate were 28.8, 11.9 and 53.9 kJ/mol, respectively. The optimum conditions for the leaching of copper from the concentrate, within the range of conditions studied were: particle size 63 per cent minus 38 ¦m, a ferric chloride concentration of 1.48 M, a temperature of 70¦C, and a stirring speed of 800 rpm.

Jan 1, 1991

The basic rule for correct design of a sample plant is that all parts of the material being sampled must have an equal probability of being collected and becoming part of the final sample for analysis. However, this rule is often ignored in the design of sample plants to save capital costs. This is false economy, because the samples taken are likely to be seriously biased and the precision may be compromised. The introduction of bias is particularly serious, because no amount of replicate sampling and analysis will reduce bias once it is present and it is often quite difficult and expensive to subsequently rectify the problem due to space limitations around the primary sampling location. This is also true of secondary and tertiary sampling stages, particularly in terms of the relationship between particle size and retained sample mass. The best strategy is to seek expert sampling advice and design the sample plant correctly at the outset.

Jan 1, 2005

In-situ leaching of gold deposits has not become an option largely as a result the lack of suitability of cyanide as a lixiviant due to sluggish kinetics and high dependence on the availability of oxygen. A second problem area is the excessive cost of drilling the required number of injection and production wells needed to service a wellfield capable of maintaining any significant throughput or providing and acceptable level of gold production. Well spacing in in-situ leaching operations is limited by solution life, dissolution rate, and the need for solution control. With cyanide the life of an active solution capable of dissolving significant gold is severely limited by the availability of oxygen which cannot be readily replaced while the solution remains underground. The extremely slow gold dissolution rate also necessitates excessive contact periods in order to dissolve coarse gold.

Jan 1, 1991

By Gibson I, Somerville J

Three main confined aquifers occur in interseam sediments beneath the planned excavation for the Loy Yang Brown Coal Open Cut. Sub-artesian groundwater pressures occur in all aquifers necessitating dewatering to prevent excessive seepage and depressurisation to prevent heaving of the open cut floor and batter instability. Reduction of water pressures in coal joints is also required to maintain coal face stability. This paper describes the depressurization and dewatering strategies, investigation for and installation of pump bores and groundwater observation bores. Approximately 5000m of drilling is carried out annually for dewatering at Loy Yang and both cable tool and rotary flush drilling methods are utilized. The cabletool method is used to obtain accurate samples for laboratory analysis, whereas rotary flush methods are used for speed and for installation of the larger diameter pumping bores. A method of re-establishing pump bores after partial excavation during mine development has been successfully developed with large cost savings. Trials are also being conducted with pre-collaring of deep bores with rotary methods then sampling the aquifer strata with a cable tool rig.

Jan 1, 1988

Records of ex-solution intergrowths with tetrahedrite as a component are rare. Intergrowths of this nature of tetrahedrite with galena have been described by Guild (1917) and Schneiderhohn (1922), and in Broken Hill ore by Stillwell (1926), but both Schneiderhohn (1922) and Gruner (1929) have commented specifically on the apparent absence of exsolution intergrowths of tetrahedrite and chalcopyrite, despite their frequent association in ores, and their related atomic structures. Schwartz (1942), reviewing the literaturerelating to ex-solution among ore minerals, lists only two instances of such intergrowths, one an occurrence of lamellae of chalcopyrite oriented along the octahedral planes of tentantite (the arsenical isomorph of tetrahedrite), the other of blebs of tetrahedrite in stannite. The only other possible instance of such intergrowths known to the author is the record of "pseudoeutectic" intergrowths of tetrahedrite with chalcopyrite and with bornite in a silver pitchblende ore from the Great Bear Lake district of Canada (Furnival,1939).Some interest attaches, therefore, to the two occurrences described below of tetrahedrite showing ex-solution relationship, in one instance with chalcopyrite, and in the other with bornite.TETRAHEDRITE-CHALCOPYRITEAn intimate intergrowth of tetrahedrite and chalcopy-rite, apparently the product of unmixing of a solid solution of...

Jan 1, 1946

South Crofty's ventilation network is large and complex. Of the total exhaust air quantity 40% enters the mine by leakage routes through old workings, this air carries high concentrations of radon gas and results in the mine becoming a classified work place under the Ionising Radiation Regulations 1985. Improvements in the control of the ventilating air and dilution by increased air quantity have reduced the average contamination to aelow-0.2 WL. The major part of the radon originates from ground water inflows and from concentrations of radium within the mine with direct emanation from rock surfaces being negligible. Of 600 kBgs-1 total radon leaving the mine 93% cannot be accounted for from known and accessible sources.

Jan 1, 1988

Australia contains a variety of iron ores, differing in grade, chemistry, size distribution and genesis. While a proportion of this ore is used world-wide as blast furnace lump, much of the material mined is high grade fines, requiring agglomeration (usually sintering) before blast furnace reduction. Sintering studies initially concentrated on the production of ferrous material of high iron content, coarse size and sufficient cold strength. In recent years research involving pilot plant sintering, precise test procedures and mineralogical analyses has focussed on the additional sinter properties of hot strength and reducibility. Aspects of mineralogical studies applied to iron ore sintering are described.

Jan 1, 1989

Incompetent ore and country rock have caused stability problems in longhole open stopes. Fully grouted pre-placed cablebolts have reduced these by preventing ground relax- ation and joint dilation to maintain a self supporting rock structure. Larger atope spans can now be opened with the same or smaller pillar. Mining methods are expected to become less dependent on original ground conditions. Effect of spacing, orientation and stress distribution along the cablebolt is not fully understood at this stage and requires more Observation.

Jan 1, 1977

By Skaviniak M

Some better perspectives applying to the exploitation and dressing of polymetallic ores in the Banskfa. gtiavnica-Hod- rusea Ore District are supposed to be achieved after a suc- cessful investigation and proving there the existence of deep-seated mineralization as well as due to increasing de- mand for non-ferrous metals and consequently to higher mar- ket prices of those recently noticed. With respect to the present situation in mining and to the further technical development as well, a several times higher exploitation may be in this region expected, especially in the deeper .eated parts of the deposit. When solving the tasks of a complex economic exploitation over the whole region, consi- derable attention is paid to regional relations and impact studies (due to expected exploitation and ore dressing but also to very difficult problems of dewatering (drainage pro- blems-). It will be first of all necessary to find there an equilibrium between the consequences resulting from the re- naissance of mining industry and environmental requests un- dispensable for the city of Banska 9tiavnica and the other neighbouring towns in the vicinity of mining plants.

Jan 1, 1988