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The karst water system in Han-Xing District is charaterised by heterogeneity in karstification and permeability of the limestone aquifer, unsteady flowing of the groundwater along karst runoff zone system, periodic recharge related with the periodic precipitation, and concentrative discharge of the groundwater in the form of karstic spring groups. The basic law is that the quantity of the water is very large during waterflood period and rather small in dry period, which has brought about difficulties and contradictions in mining and water supply. The measure to bring the karst water under control must be based on the principle of comprehensive ways and on the systems engineering method. Macroscopiclly, it is the reasonable countermeasure to retain surface water in the upstream section of the karst water system and to strengthen infiltration in the midstream section and to combine exploitation and utilization of the groundwater with water protection and mine dewatering in the area in which mines are distributed.

Jan 1, 1988

By Browning E. J

The application of conventional dust control systems in British Coal mines has considerably reduced the incidence of pneumoconiosis. A number of new techniques have been developed involving extraction close to the cutting heads of mining machines which will be capable of controlling airborne dust with the greater intensity of production necessary in the present economic climate.

Jan 1, 1988

By Doxford CI, Perry AJ

Mining Lease 908, situated on Gorge Creek near its confluence with the present Cape River system, has been subjected to intensive recent exploration for alluvial gold.The gold is hosted by a buried palaeochannel, the Gorge Creek Lead and by an overlying remnant meander of the Cape River. The principal, if not sole, sources of gold within the Gorge Creek Lead are the northwest trending Great Australian Reef and Green's Specimen Reef systems which are situated on adjacent high ground. Lower grade gold bearing eluvial ground separates the reefs from the Gorge Creek Lead. The sources for gold within the old Cape River system channel (Canton Lead) are thought to be situated some distance upstream, one source perhaps being the Lolworth Diggings located 30 kilometres to the northwest.Exploration of previously "heavily dug" ground on both leads consisted of detailed geological mapping followed by the collection and treatment of bulk samples from eight costeans. The wash samples varied in size from 120 to 396 cubic metres. Treatment was undertaken through a commercial sized conventional wet screen and jig plant.

Jan 1, 1986

By Joussemet R, Fabre F

The paragenesis of the Escuzar Mine (Andalusia-Spain) comprises: ò major constituents: celestite and carbonated minerals (abundant calcite and less frequent strontianite). ò minor constituents: sulphates (gypsum and anhydrite), clays and some iron oxides and hydroxides. The average content is at about 60 per cent SrSO4. Since liberation size was fine (from 30 to 50 ¦m), the flotation method was chosen. Laboratory batch tests have shown the relevance of using alkylsulphates with as long as possible hydrocarbon chains. The recovery obtained led to an expected 95 per cent SrSO4 concentrate with nearly 70 per cent recovery. Pilot plant tests (160 kg/h) have confirmed these results and attained a recovery of more than 65 per cent of a 96 per cent SrSO4 concentrate. Extrapolation to the industrial scale (14 t/h) has been successfully carried out : up to 600 t of a concentrate at more than 95 per cent SrSO4 has been obtained. Non optimised recovery has already reached 60 per cent for a 97 per cent SrSo4 concentrate.

Jan 1, 1993

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

By Andrews JRG

Chrysotile asbestos is a valuable resource. Used as a reinforcement in asbestos cement, products are obtained which are cheap, are not attacked by vermin, do not rot or support growth of fungi and are unaffected by water or humid conditions. Such products are of great value in the developing countries where inexpensive and durable building materials and pressure pipe are very important to development, housing and water supplies. Concern over the adverse effects of inhaling asbestos has led to the introduction of increasingly stringent controls world wide on the quantities of airborne asbestos per- missible in the occupational situation. Wet processing has the potential for virtually eliminating the environmental concerns with asbestos dust both in fibre production and in the materials handling section of the manufac- ture of asbestos cement products. In addition, high efficiencies associated with wet process- ing mean that better yields are obtained and that the tailings which are dumped have a lower residual asbestos content. Since early 1977, ICI Australia and Woodsreef Mines have been engaged in a programme of research to develop and evaluate a wet mill- ingprocess to produce, from ore and existing tailings, high grade fibre suitable for use in asbestos cement products. The process has been developed through microscopic studies, labora- tory bench scale experiments, work in a small scale semi-continuous plant and product evalua- tion on experimental size Hatschek asbestos cement machines. A prototype mill with a normal feed rate of 1z tonnes per hour and capable of producing pipe grade asbestos from Woodsreef ore has been constructed and was operational from January, 1982 to July, 1983. A range of asbestos cement products have been made successfully on full scale Hatschek machines using fibre from ore and tailings milled in the prototype mill. Economic evaluations indicate that a wet process mill would be cheaper to build, operate and maintain than an equivalent dry process plant. A commercial plant has been designed 1. Manager New Process Development, Woodsreef Mines Limited, Barraba, Australia. 2. Senior Lecturer, Department of Chemical Engineering, Monash University, Vic, Australia. formerly Senior Research Officer, Research Department, ICI Australia Limited

Jan 1, 1986

Systematic ICPES (Inductively coupled plasma emmission spectrometry) analysis of magnetic concentrates from drainage samples has been used to discriminate concentrates dominated by magnetite from those dominated by pisolites, presumably maghemite-rich. In addition, a set of spurious zinc enhancements was recognised and explained with the help of mineralogical data, and systematically isolated using chromium as a Discriminator.

Jan 1, 1987

By Roderick W. F

The equipment and procedures used for green pellet production on a laboratory scale are given, together with a description of the straight grate pellet strand analogue which has been developed to examine the response of various ore types to heat hardening. The capabilities of the analogue are illustrated with data obtained from the balling and drying studies using a manganese ore. Differences in inter-batch pellet quality are discussed, and method of minimising the experimental error that can arise from these differences is Presented.

Jan 1, 1974

By B Muller

The disposal of tailings has become a greater issue due to the changing economics of mineral extraction. The processing of lower grade deposits and tougher environmental regulations has led to the selection process for tailings disposal options becoming more complicated. Current selection methods are too time consuming or too easily manipulated for inexperienced users to use successfully. This paper examines a different method for the initial selection of a tailings disposal system, using a numerical system that was introduced into the mining method selection field. The numerical method system was compiled by reviewing previous work done on the positive and negative aspects of the tailings disposal methods used by the coal and metallurgical mining industries. Assessing the common trends and design aspects of each of the methods was undertaken and a ranking was designed to explain how well suited the tailings disposal methods are to a situation. The tool successfully analysed sites using common data to indicate methods for disposal that would have provided minimal technical problems, low environmental risk and been practically possible. The tool also proved successful in identifying critical areas that would need further investigation. This new system was tested on some disaster case studies from around the world in order to show that it could have successfully selected a different method for tailings disposal that would have prevented the disaster.

Sep 26, 2011

By F Pothitos, S Hewson

The geological and geotechnical conditions at the Cadia Hill Open Pit are very complex. This complexity coupled with high mining rates has required significant technical input into the design and optimisations of the pit slopes, accesses, cutbacks and scheduling. A multi-discipline team of NML engineers, geologists and external consultants has been conducting comprehensive geological and geotechnical programs in order to achieve an optimum design of the pit slopes. Extensive data collection, analysis and interpretation has led to the formation of working geotechnical models of large structures, rock masses, and back-analysed slope performance charts. The current Cadia Pit Optimisation Project focuses on the risk-and-return principle for pit design and on the integration of geotechnical, hydrogeological, mining engineering and scheduling. The risk management for pit design has also been incorporated into the short term and long-term operation of the pit mining to ensure safety and production.

Jan 1, 2003

By L Soares, W T. Hennies, F Fujimura

A methodology of environmental performance evaluation in mining developments is proposed, as well as guidelines and procedures for obtaining information to improve their environmental performance. Environmental performance is the results of the mining activities and their relation to environmental issues. If this evaluation is carried out on an on-going basis, it is possible to anticipate or to identify the formation and development of an environmental impact in its early stages. Evidence or trends identified by environmental evaluation provide valuable information to prevent further damage. The proposed methodology is based on the significant environmental aspects of a selected monitored job site by environmental indicators which are then compared with previously defined environmental criteria and targets or goals. The methodology procedures also take into account the environmental accounting of the investments and expenditures.

Jan 1, 2003

By Gray J, Krouse HR, Changkakoti A, Morton RD

A group of stratabound-stratiform Fe-Ba-Zn-Pb-Ag deposits within the La Minita mining district of Michoacan, southwest Mexico have been investigated. The results of the study show that these deposits were generated around submarine hot-springs issuing in a Cretaceous island-arc environment. The exhalative mineralization, which is both epigenetic and syngenetic in character, was developed above fault-systems which constituted the loci of both volcanism and subsequent hydrothermal systems.Fluid inclusion data suggest two hydrothermal events during ore mineralization, one at 240¦C and the other at 161 to 205¦C, with salinities between 2.1 and 12.8 wt.% NaCl equivalent. Stable isotope data support a marine origin for the ore-fluids, as well as, for carbon and sulfur. Strontium isotope data suggest that Sr in the barites was extracted from the volcanics and limestones by circulating seawater. The ore-depositional environment was one of shallow, sub-tropical marine character, where mineralization was in part geochemically controlled by carbonate reefal facies within the volcanic/pyroclastic suite.

Jan 1, 1990

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 Kwok S, Haemmerle A

Treatment methods for a low grade deposit at Mt. Fitch near Rum Jungle, N.T., were investigated. Physical beneficiation of the ore, sulphuric acid leaching, carbonate leaching and various methods of uranium extraction from the leach liquor were studied. Although the deposit occurs in a carbonate environment, acid leaching of the ore after beneficiation by radiometric sorting appears to be the most economic treatment method. Uranium would be recovered from the leach liquor by solvent extraction.

Jan 1, 1970

By D Matthews

With a brownfield project comes control integration challenges. The Khumani Iron Ore Mine’s second phase expansion posed a number of challenges as there was substantial brownfields work conducted. The fi rst phase was the compilation of the modifi ed process functional specifications for the project. The second phase was an audit on all of the operational sequences; this included a comparison between the SCADA sequences, sequential starts analysed from the historian data (with the potential for improvements made by the plant operators in manual start-ups) and what was proposed in the process functional specification. Differences, inclusions and missing equipment were highlighted. The third phase was the comparison of interlocking and control in the PLC with the updated process functional specification; this was done during the coding process. Running parallel to the three phases was the SCADA integration; tie-ins to the existing SCADA were conducted on maintenance days and shutdowns, in many instances with ‘dummy’ equipment to get the operational staff accustomed to the new interface. This paper details each of the phases, the success of this methodology as well as the pitfalls experienced.

Jul 11, 2011

By Davies C. E

At present the source of virgin iron for steel produced in New Zealand is titanomagne- tite extracted from titaniferous beachsands. Some of these beachsand deposits contain extractable quantities of ilmenite as well as titanomagnetite and both minerals represent challenging sources of vanadium and titanium products in addition to iron. This study looks at some theoretical aspects of smelting these ores directly with coal rather than with electric power, and takes into consideration the properties of the raw materials, the thermodynamics of possible process routes and the background of the economics involved.

Jan 1, 1980

Differences in the assay results of replicate samples engender doubts on the reliability of ore sampling and of assaying procedures. An analysis of variance is a technique to estimate the variability at each level of the procedures. In an example, the variability of one-metre core samples was far greater than that of the assaying technique.

Jan 1, 1976

Laboratory scale simulation experiments show that the adsorption capacity of Au(CN)Z- on activated carbon in the presence of organic plant contaminants is dependent on the particle size of the carbon. This observation suggests that fine carbon in a CIP contactor can protect coarse CIP carbon from fouling in a dirty CIP plant. A preliminary test of this concept was made using fine lignite coal as the organic scavenger in the presence of the CIP carbon Calgon GRC22 in an alkaline cyanide solution containing Teric 401, sodium ethyl xanthate and kerosene.

Jan 1, 1991

The five main ways in which coal is used are1. for electricity generation,2. as a lump fuel for domestic and industrial purposes,3. for gas making,4. for making carbon for chemical and metallurgicalindustry, and5. as a source of coal tar and coal-tar chemicals.In the past about 80 per cent of Victoria's brown coal has been used for power generation and the rest for making a lump fuel, in the form of briquettes. Some of these briquettes have been used for gas making, and a carbon industry based on them has recently been commenced, and could expand rapidly. However the enormous increases expected in power requirements, approximately a doubling every 10 years, will ensure that even if the manufacture of carbon increases dramatically and a large amount of coal is used for other purposes, the brown coal industry will always be dominated by power generation. As new fuels such as natural gas, oil, and nuclear fuel become available at competitive prices these will take their share of the power generation load.Natural gas or oil, or possibly pumped storage hydro, will almost certainly be used for all future peak-load stations, comprising around 40 per cent of the total installed generating capacity, but new base load stations will continue to be designed for brown coal operation until about the mid-1980s, by which time nuclear power stations will become competitive. By this time Victoria will have installed about 6000 MW capacity of brown coal stations, burning around 50 million tons/year of coal, compared with 18 million tons/year at present, with perhaps 15 million tons/year being used for other purposes.This consumption of 65 million tons/year should then remain fairly stable over the life of the power stations installed, well into the 21st century. Brown coal therefore appears to have an assured place in providinga major part of Victoria's fuel requirements, despite the diversification in fuel usage pattern which appears certain to occur with the recent developments in new fuel resources.

Jan 1, 1971

Seam gases are the most important atmos- phere contaminants in Australian collieries, their importance increasing with depth; C02 as well as CH4 may be important in intruded envir- onments. The generally high rank of the coal, with low moisture content, makes for abnormal dust production. The other contaminants are introduced and subject to better control, in- cluding products of spontaneous combustion. Due to market situations the generally lower rank and higher sulphur coals more prone to self heating are mined less. Future mining at greater depths should see greater problems with atmosphere contaminants.

Jan 1, 1983