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By M Zaluski, D Bless

An innovative, biological treatment process has been designed by MSE Technology Applications, Inc to treat and control acid mine drainage (AMD). A field-scale demonstration is being conducted under the Mine Waste Technology Program using water flowing from a historic mine in Montana. A successful demonstration of an in situ process will allow it to be employed at numerous other abandoned or remote mines, which discharge AMD, an acidic, metal-contaminated water. Conventional treatment methods are costly and are often impossible to use at remote locations. MSEÆs technology uses a biological system to clean up AMD. The In situ Passive Biological Treatment Process utilises nonpathogenic bacteria, which are able to neutralise acidic mine water and remove contained toxic metals. These bacteria live within a series of pile-type reactors inside the mine. The bacteria are fed inexpensive waste products. The resulting discharge is clean water flowing from the mine. This presentation will show that this technology offers a natural cleanup method for the nationÆs numerous abandoned mines. Work on this project was conducted under Interagency Agreement No DW899388-70-01-1 between the US Environmental Protection Agency and the US Department of Energy (DOE), and was performed at the Western Environmental Technology Office through the DOE National Environmental Technology Laboratory (DOE Contract No. DE-AC22-96EW96405).

Jan 1, 2003

The development of the lower Hunter Valley, centred around Newcastle and its suburbs is closely linked to the mining of coal and the settlements which grew to house the colliery officials, the miners and their families. The Port of Newcastle expanded and developed as a port exporting coal to many ports of the world ranging from Hawaii and Brazil to Japan and Korea. The coal which passed through the Port of Newcastle, depend- ing on the historical period in question may have been mined in Newcastle itself, or one of the nearby colliery townships such as Lambton, Wallsend, Charlestown or Hamilton, or from one of the estuarine collieries located at Carrington or Stockton or from the West Wallsend area or from East Greta, Pelaw Main or Cess- nock located on the South Maitland (Greta) coal field or from the open cut and underground mines of the Singleton Coal District.

Jan 1, 1988

By J Szymanski, S Planeta

Extensive rockfill cylinder testing was performed to determine the effect that aggregate size, aggregate moisture, Portland cement, fly ash and cement dispersant addition has on compressive strength of a cemented backfill. In this paper ætwo-level factorialÆ and æcentral compositeÆ designs were used to determine the single and interaction effects that each factor have on the overall strength. The results from the designwork indicated that the per cent of aggregate fines had the greatest influence on the compressive strength of the rockfill cylinders. From the factorial design results, a compressive strength estimation equation was derived, which enables the strength to be estimated, given varying input values.

Jan 1, 1998

By Gochin RJ

This paper focuses on measures of the economic significance of mineral exploitation and processing activities, such as beneficiation, refining and smelting. Empirical measures are suggested to quantify the relevance of the degree processing within a nation's mineral industry. The most useful, based on the input-output econometric framework, are used to establish the magnitude of links between the mineral industry and its satellite activities and for the appraisal of large, non-marginal projects. The input-output impact analysis is refined to allow for country specific behaviour and synthetic indices for the appraisal of investments in the mineral sector are developed. These indices are further improved with the introduction of shadow prices to incorporate socio-economic issues. They are useful to direct mineral policy decisions and several investments towards the most promising objectives for national goals. Finally traditional methods for the appraisal of small scale, marginal, mineral projects are assessed where local impact and regional development issues are more relevant than national ones.

Jan 1, 1993

No paper was submitted for the proceedings, verbal presentation only (no material available).

Jan 1, 1998

The paper considers the factors that will control the importance and the nature of R & D required by the Australian mineral industry over the next decade. The process required to determine the appropriate priorities for research and how it must be managed is described. The work of the Australian Mineral Industries Research Association is used to illustrate this process.

Jan 1, 1986

MIM Holdings Limited (MIM) committed to a long-term future in copper in the Carpentaria Mineral Province in 1996 with the development of the Enterprise and Ernest Henry mines, and an upgrade of MIMsÆ copper smelter in Mount Isa, and copper refinery in Townsville. The upgrade of the copper smelter will enable the smelter to produce 250 000 tpa of copper with a single primary smelting unit, the copper Isasmelt furnace installed in 1992. The copper Isasmelt furnace currently smelts concentrate containing 145 000 tpa copper. To reduce the risk associated with the copper smelter upgrade, and shorten the ramp up time of the upgraded smelter, two high-rate trials were undertaken in 1997 to demonstrate that the copper Isasmelt furnace could, with an additional 525 tpd of tonnage oxygen, treat concentrates containing 250 000 tpa copper. During the trials the concentrate feed rate to the Isasmelt furnace was increased from its average rate of 100 tph of concentrate to 150 tph of concentrate. The increase in the capacity of the furnace was achieved by: supplementing the installed tonnage oxygen capacity of 595 tpd with an additional 300 tpd supply; reducing variability in the furnace feed rate from ¦25 per cent to less than ¦5 per cent; and reducing tramp air. The Isasmelt furnace smelted concentrate at a rate of 140 to 150 tph for four hours 25 minutes during Trial 1, and at a rate of 150 tph of concentrate for five hours and 30 minutes during Trial 2. The oxygen utilisation was 100 per cent during the trials with the process remaining under control. As a result of the development work for the trials the average treatment rate of the furnace under normal conditions increased by ten per cent.

Jan 1, 1998

By Ennis P. C

The Mt Keith ultramafic intrusive extends for about 200 kilometres from Agnew in the south to Wiluna in the north. It forms the host for a number of nickel sulphide orebodies including Mt Keith and Honeymoon Well. Long fibre minerals are associated with the orebodies. The presence of these minerals impacts on the issue of tailings disposal from several standpoints, particularly the slurry beaching properties and dust generation from dry beaches. Central thickened discharge (CTD) is an innovative method of tailings disposal that involves stacking tailings in a low conical hill instead of storing them in cells. In appropriate circumstances this leads to savings in capital costs and operating expenditure. The method was introduced to Australia in 1981, and is currently employed at four operating mines, Elura and Peak Gold, both at Cobar in NSW, McArthur River in the Northern Territory, and Union Reefs near Pine Creek, also in the Northern Territory. It is the proposed method for Century Zinc and Ernest Henry, both in Queensland. The paper describes laboratory test work and design parameters for the application of the method to tailings disposal at Honeymoon Well and compares them with comparable data for other CTD systems. Of particular relevance for design purposes are beach slope, density, and water recovery. Wind tunnel tests were conducted on the Honeymoon Well tailings samples to investigate dust generation from the dry beach surface and it was concluded that dust generation from an undisturbed beach would not occur because of crusting.

Jan 1, 1996

By Fredley D. C

Georgius Agricola wrote in De Re Metallica in 1556 that a prudent a miner should not work in a region ruled by a tyrant-a person inimical to mining. In 1926, Associate Chief Sherman of the United States Forest Service in a speech stated, "It is the policy of the Forest Service to encourage the development of the mineral resources within the boundaries of the National Forests ... a man who fails to cultivate a friendly, helpful, cooperative spirit in his relations with those who are endeavoring to develop the mineral wealth of our mountains has no place in the Forest Service." Both statements are as true today as they were in 1556 and 1926. The challenge to the Forest Service and the mineral industry today is to maintain that cooperation in a world that has changed significantly since Agricola and Sherman. The United States Forest Service manages 77,000,000 hectares of land-mostly in the Western United States-an area equal in size to New South Wales. The vast majority-75 million hectares are National Forests, and 1.6 million hectares are National Grasslands. National Wilderness Areas account for 13 million hectares or rough- ly 17 per cent of the National Forest System. National Forest System lands (NFS) are some of the most visible, scenic and controversial lands in the country. They are also some of the most valuable for their mineral potential and production. The value of mineral produced exceeds US$4 billion per year. There are over 1200 producing mines, 15,000 oil and gas leases, and some of the largest lead, copper, silver, gold, platinum, molyb- denum, and coal deposits in the hemisphere. Every year the Forest Service approves nearly 5,000 mineral operations on the NFS. Much of the NFS (75 per cent) is open to location of mining claims pursuant to the 1872 Mining Law. And an equal amount of land is legally available for oil and gas leasing.

Jan 1, 1991

Competitive commercial circumstances internationally provide a prime impetus for miners to seek new technologies as a means to profitability and survival. Engineering and project management activities play a vital role in establishing, operating and developing the capital facilities used by miners. Computer based technologies are the single most important technology for maintain- ing competitiveness in engineering and project management into the future. Current applications of computers in engineering design and drafting are finding economic applications, computer-aids are more readily introduced, accepted and profitable. Computing technology is advancing very rapidly and on a broad front in hardware, software and communications. This technology advance is improving the ability of engineers and project managers to provide a high quality, responsive and low cost service which will improve in parallel with computer technology. As this technology advances, a key challenge is created for managers in selecting hardware and software, in developing people and organisations and in marketing the technology to advantage. While the future holds many exciting developments, people will still hold the key roles. While the nature of their roles may change, the final acceptance or rejection of technology will be by people, whether as users or owners, who will judge on the basis of whether their stake is improved or not.

Jan 1, 1986

By Nowell SB, Cottrill DA

Host-rock - wallrock major and trace element geochemistry associated with epithermal gold mineralisation in the Hauraki Goldfield of New Zealand is poorly documented, even though rock geochemistry is a recognised tool in exploration. Such responses assist in recognition of the regional scale imprint of fossil hydrothermal activity, and indicate targets for detailed evaluation within these alteration zones.Recent investigation of gold deposits in the Waihi (Gladstone), Golden Cross (Empire), Thames (Waiotahi) and Coromandel (Tokatea) areas indicate enrichments of Au, As and Sb in the andesitic wallrocks hosting mineralisation. Of the other elements examined, Si, K and Rb are enriched, and Na, Ca, and Sr are depleted at all deposits. These trends are best developed in the vicinity of veining. In deposits with clay alteration dominating (Waiotahi and Tokatea) there is also depletion of Mg, Mn, Zn and Cu. Ba and Cr are variably enriched or depleted within different styles of alteration. Base-metal enrichment in the wallrocks is not a feature of Hauraki deposits.

Jan 1, 1990

By Glastras M. V

The presence of arsenic in solutions which result from the processing of many sulphide minerals leads to a need to understand its speciation in aqueous systems and the reactions of those various species. This paper deals in particular with the precipitation of arsenic from aqueous solution in the form of insoluble inorganic compounds in order to remove arsenic from various hydrometallurgical process streams. The solubility and stability of the precipitates is examined. It has been found that many of the arsenic compounds presently used are more soluble than previously accepted and unstable in disposal sites such as tailings ponds.

Jan 1, 1987

By Rynn J. M W, Paynter A

Recent studies by the authors have concerned themselves with assessing the earthquake risk to north-eastern Australia, based on available historical earthquake data for the area. There have been several significant earthquakes (Richter local magnitudes of the order of 6) concentrated in the Wide Bay - Burnett region in central eastern Queensland, although none of these has occurred close to a significant centre of population or development. Using derived average acceleration attenuation relations and world-wide data on earthquake-induced damage as a basis, conditions under which earthquake-induced liquefaction may occur have been investigated and presented in graphical form. Historical earthquake data for north-eastern Australia have been overlain on this graphical presentation and it has been demonstrated that the Wide Bay - Burnett region, in particular, may in the past have been on the verge of earthquake-induced liquefaction, where ground conditions are susceptible. When this is viewed in the context of the rapid growth in population and development in this area over recent years, the risk can no longer be ignored with impunity.

Jan 1, 1990

Since the mid-1970s there has been increasing attention in the South Pacific area to the problems of disaster planning and management at various levels, mainly from regional through national to provincial levels. This concern has been expressed in a variety of ways. International aid donors have made their views known in commentaries or reports. Seminar discussions have been organised at the regional level (such as at Suva, 1976; Suva, 1979; Tonga, 1982 and Suva, 1983). In-country training workshops or meetings have been organised (such as the "Disaster Preparedness Workshops for Non-governmental Organisations" in Pacific countries, jointly run by the Australian Red Cross and the Australian Overseas Disaster Response Organisation and supported by AIDAB, in Vanuatu, 1985; Solomon Islands, 1985; Western Samoa, 1986; Fiji, 1987; Tonga, 1987; Lae and Port Moresby, Papua New Guinea, 1988) or held outside the area (ACDC at Macedon, 1981). Training and/or research institutions have been established such as the East-West Center, Honolulu, and the Asian Disaster Preparedness Center, Bangkok (more Asia oriented). As part of the East-West Center Pacific Islands Development Program's Disaster Preparedness Project, a detailed manual of disaster preparedness and response procedures and guidelines has been published (Carter, 1984).Table 1 and figure 1 show that the area with which this discussion deals is a highly fragmented island region, comprising many small, some minute, nations, both in land area and population. The social structure is predominantly rural, with the capital city often making up a small part of the total population and, in absolute terms, little more than a small town. Outside the administrative and governmental activities concentrated in the capitals, in most cases the indigenous inhabitants depend on subsistence agriculture or on usually a monocultural concentration on a cash crop, most frequently coconuts.

Jan 1, 1990

In process industries, time-dependent random fluctuations of raw material characteristics and mass flow rates in bulk material or pulp flows cannot be always prevented for different reasons, eg because of the geological situation (no uniform formation of the deposit) or/and because of technological reasons (segregation in bunkers or on stockpiles). Since a long time, there has been practical experiences that such fluctuations can have negative consequences, eg: ò fluctuations of the final products characteristics, ò higher expenditure for process control, and ò worsening of technological characteristics (recovery, sharpness of separation etc). In the literature, there can be found a lot of details as to, eg the improvement of the sharpness of separation in a jig in dependence on the raw material blending (Kubitza, 1981; Gathen, 1983) or the decreasing flotation recovery with increasing raw material characteristics fluctuations in iron and potash ore processing plants (Bubnova, 1978). Up to now, however, these consequences of random fluctuations, eg on the separation efficiency were not predictable theoretically. It could be shown by means of the general model for mechanical macroprocesses (Graichen, 1989), that the reduction of input fluctuations passing a blending facility can be calculated in this way. In this example, the steady state of the process is the wanted one, but, in general, the model is able to describe also non-steady states of the process regarded. On the other hand, the general model of mechanical macroprocesses has been used successfully for modelling separation processes, eg cross-flow and air classification (Molerus, 1969; Neesse, 1991; Senden, 1979; Tichonov, 1973). That is why it was tried to model the influence of input fluctuations on the separation efficiency, that means, the impact of non-steady states - as a consequence of random fluctuations - on a separation process. The models discussed in the literature are related nearly exclusive to the steady state of the process. The reasons for that lie in the (relative) simplicity of the models and the fact that the steady state is aimed at by means of blending processes under practical conditions - because of the advantages mentioned above. These models cited have proved to be superior to other models, since the basic general model for mechanical macropocesses makes possible the consideration of turbulence acting in the process unit and influencing the separation process essentially. This is valid also for modelling the turbulent cross flow classification, applied to mechanical classifiers and hydrocyclones, where the correspondence between the separation characteristics (cut size, separation sharpness) calculated and determined experimentally is much better than for other models.

Jan 1, 1993

By Schofield N. A

The cross-sectional method of stope grade estimation at Cobar Mines has consistently had several shoneomings, me most imponant of which being mat stope grade is significantly overestimated in the high grade lenses.The use of mree-dimensional ore lens modelling improved the grade estimation and ore waste definition but significant overestimation still occurred in me high grade stopes, particularly those wim extremely variable grade distribution. The implementation of an indicalor kriging based method for mapping of me high grade copper mineralization has significantly improved the quality of copper grade estimates and provides a mineralisation geometry similar to that generated manually by me mine geologists. This paper presents the results of a test case study in the application of indicator kriging to the mapping of the copper grade in two stopes in the QTS North mineralisation. The results are encouraging in that they prov ide coofi rmation of the geometrical model developed by the geologists and much improved estimates of the grades of me stopes whencompared to me grade reponed from mining these stopes.

Jan 1, 1993

By Cunningham CG

Many epithermal gold-silver deposits areknown to occur in the Neogene-Quaternary volcanic complex of the central Andean region of southern Peru, northern Chile, western Bolivia, and north-western Argentina, an area of about 300,000 km2 where these volcanic rocks constitute the dominant cover. Some of the gold-silver deposits were mined during Spanish colonial times, as early as the 16th century,- whereas others were not discovered until the 19th and 20th centuries. The extraordinary gold-silver potential of this young volcanic complex, however, was not recognized until the 1970's when the phenomenal increase in gold and silver prices stimulated new exploration. New discoveries were made, chiefly in southern Peru and northern Chile, of high-grade ores in old mining districts and large low-grade ore bodies, both in old districts and in new areas having no history of mining activity. Many additional gold and silver deposits remain to be discovered within and beneath the young volcanic complex of this region.

Jan 1, 1990

By Osborne V. J, Urbank W

An explosion occurred at Moura No. 4 underground coal mine in Queensland on 16 July 1986 and resulted in the loss of 12 lives. The official report of the accident concluded that the most likely source of ignition was the flame safety lamp. This paper describes an investigation of the behaviour of a flame safety lamp, similar to the one involved in the Moura explosion in atmospheres of methane, coal dust and air, carried out at the Queensland Department of Mines . Testing and Research Station. The behaviour of the lamp is described in conditions of varying methane and coal dust concentrations in air, and varying air velocity. Particular emphasis is given to the 'phenomenon of burning which occurs inside the gauze and which is capable of causing the ignition of an external explosive atmosphere.

Jan 1, 1988

By Kellerwessel H, Oberheuser

Since its invention by Professor Klaus Schonert of the University of Clausthal, Germany, high pressure rolls comminution has attained near total acceptance as the preferred method of size reduction in the cement industry. Over 300 units have been manufactured worldwide. At locations where the system has been installed, considerable energy savings have been realised. These energy savings are generally in the range of 20 to 30 per cent compared to conventional ball mill circuits. However up to 50 per cent power saving has been achieved at some installations. This technology, with the exception of the diamond industry, has up to now had only limited success in ore processing. This has mainly been attributable to the abrasiveness of ores encountered in this industry leading to high wear rates. These high wear rates have given rise to an unacceptably short life time of the wear surface of the rolls, requiring regular replacement. A new wear surface has been developed which has shown to give a ten-fold increase in service life over conventional surfaces. This, together with developments made in machine design now give the units the ability to attain the high availabilities demanded by the mining industry, and therefore to allow this industry to achieve the considerable operating cost savings offered by the high pressure rolls.

Jan 1, 1992

By Kupper T

Firstly, electric analog models are discus- sed to show fluid streaming conditions. In these models the depth of blast at tuyere level, the height of the bath, the influ- ence of different angles of the furnace zones and the different possibilities of the root of the cohesive zone have been changed. Tests to define the influence at a large blast furnace are given. Secondly, the wear of carbon bricks in the hearth is examined under the influence of gas, slag and pig iron. Oxidation tests in a special scanning microscope with the pos- sibility of heating and gas treatment are shown. Wear mechanisms are discussed fora large blast furnace and proposals for im- provement are given. Finally, the possib- ilities and value of the temperature meas- urement in the hearth block are discussed.

Jan 1, 1981