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Analysis of different environmental scenarios and to represent, spatially, of impacted areas is possible by the use of geoprocessing techniques, specifically Systems of Geographical Information (SIG). Through these systems it is possible to create dynamic mathematical models, constituting of a georeferenced digital database and employing the integrated data originated from several sources. In this context, the general goal of this paper is to apply this tool in an environmental analysis of a specific karstic area impacted by mining activities. In order to preserve a limestone site, internationally recognised by its archaeological features, including caverns, lakes and evidences of prehistoric ages, the Brazilian government has created the Lagoa Santa Environment Protection Area. This place is located in the proximity of the Belo Horizonte international airport. In the past two decades exploitations of dimension stones have increased in this area. These exploitations have been done without a mine plan promoting several environmental impacts. The objective of this paper is to analyse these activities using SIG as a basic tool to locate the main mining related impacts and propose mitigation measures including waste and tailings disposal and reshaping of the landscape and introducing a drainage system for the considered zone.

Dec 6, 2010

By B Ilich, M Brad, R Brandli, E MarT

The Wirtgen surface miner was investigated for application to the Cloud Break iron ore deposit since it can selectively mine thin seams and there is no requirement for drilling and blasting or primary crushing as the surface miner cuts and breaks the rock to secondary cone crusher feed size. A physical metallurgical study of the surface miner run-of-mine (ROM) from Cloud Break was conducted to better understand the product size distribution, amount of -31.5 +6.3 mm lump produced, lump stability and physical metallurgical quality compared to conventional drill and blast techniques. Since the Cloud Break mine was not in production, the lump product from crushing and screening of surface miner ROM was compared with product simulations using traditional premining physical metallurgical processing techniques including drop testing of PQ diamond core. Drop test conditioning is widely used in the iron ore industry to simulate blasting, crushing and screening at the mine and subsequent product degradation during handling from mine to port to predict both the amount of lump product on ship and the size distribution of the fines and lump. The size distributions of surface miner ROM for hard, medium and friable ore types show very tight size distributions with very little above 100 - 150 mm, about 60 per cent of the distribution between 75 and 6.3 mm, with less below 1 mm compared to conventional drill and blast ROM. Crushing, screening and drop test conditioning of the surface miner ROM produced more lump in equivalent ore types compared to drill and blast techniques or their breakage simulation using PQ diamond core. The higher lump yield from the surface miner was also confirmed by pilot scale crushing of some 7400 t of surface miner ROM from the Cloud Break trial pit. The lump produced from surface miner ROM was quite stable and showed similar low degradation characteristics to lump simulated from drill and blasting techniques. Product size distribution simulations using conditioned crushed lump from 1 m diameter Bauer hole samples were found to compare well with processed PQ core samples and surface miner product from trial mining at Cloud Break. The Bauer sample method is therefore considered to be a very useful close simulation to actual lump production, although the lump yield is lower.

Jan 1, 2007

A simple method of designing effective fill drainage systems for slurry backfill is presented. By using the proposed method, it is easy to calculate and predict the expected fill drainage rates or to provide additional drainage systems to accelerate the fill drainage. The fundamentals of hydraulic fill and an efficient method to determine its permeability is also explained. The safety in hydraulic filling and bulkhead stability depends totally on achieving effective drainage regime for the fill. This paper provides the basis for creating such efficient drainage regimes. The recent fatal fill bulkhead failures in Australia were the result of poor drainage from the respective fill masses, and therefore it is more important to provide suitable drainage arrangements to continue using hydraulic fill to the benefit of the mining industry. At present there is no procedure available to mine operators to estimate the expected bulkhead pressures to design a satisfactory bulkhead. Some mines are constructing bulkheads after their initial investigations carried out years ago. Other mines have simply borrowed the ideas from the pioneer mines and using in their areas. It is high time that we develop a rational approach to estimate the expected bulkhead pressures for the design of bulkheads. We need a simple model that could be understood and used by the mine operators on a day-to-day basis. This paper also presents a model to predict the bulkhead pressures for designing safe bulkheads.

Jan 1, 2002

By Mahoney M

For gas content analysis in recent years, it has been standard procedure to report results on a 'dry ash free' (daf) basis, under the assumption that gas only adsorbs onto coaly material. In order to test the relationship between ash and sas content, samples of various rock types were taken from two drillholes in the Newcastle Coalfield. The results of this study confirmed the correlation between gas content and ash, providing an accurate means of relating gas contents for all carbonaceous rock types.

Jan 1, 1995

By Edwards A. B

This paper presents the results of an examination of four samples representative of the low-lead matte, high-lead matte, lead speiss and antimony speiss, respectively, produced during smelting operations at Port Pirie Smelters. The investigation was undertaken at the request of the Broken Hill Associated Smelters Pty. Ltd., as part of the research programme of the Mineragraphic Section of the Council for Scientific and Industrial Research.Analyses of the specimens are as follows:-

Jan 1, 1949

By Corbett GJ

Epithermal gold-silver deposits occur in young volcanic terrains where post-mineral cover commonly impedes the search for mineralisation. At the Togi Project in Honshu, Japan, a complex mineralised system is largely covered by post mineral volcaniclastics. A combination of high resolution electrical resistivity surveying and detailed airphoto interpretation has, with close geological control, enabled synthesis of structural and alteration characteristics of the Togi geothermal system, in turn permitting ranking of the prospects for drill testing.

Jan 1, 1990

By Bin H

East Guangdong tin province overlaps the southmost part of the mesozoic magmatic arcof continental margin type in Southeast China and is dominated by mesozoic syntectic magmatism,which associated to tin mineralization. It is distinguished from Nanling tin province but quite close to NW Bolivian tin province in both tectonic and magmatic relations.Tin deposit's mostly of cassiterite-sulfide, cassiterite-silicate formations are localized along exsocontact zone of granitoid batholith or stock, boundary area of volcanic depression, or, within volcanic edifice. Petrochemistry studies show tin was concentrated as intermediate-acidic magma evolved by fractional crystallization. Xiling tin deposit of vein type related to extrusive... the lava dome was formed at T C 221-301 and at very shellow depth,seems to correspond to type A in classification for Bolivia tin deposits by J.N.Grant. Tashan tin deposit of dissemination type related to hypergene intrusive facies,with mineralization occured in endocontact zone of granite porphyry dykes is considered as porphyry type,which spported by H-0 isotope and gas-liquid inclusion evidences. It formed at T C 250-430, comparable to Bolivia porphyry tin deposits,but at a greater depth 1.3 3.0km.A model for known tin deposits in East Guangdong was worked out. A good prospecting perspective was revealed for the potential type of tin deposit in East Guangdong--subvolcanic porphyry tin deposit.

Jan 1, 1990

By Leahy GJ, Wright DJ, Player RI

The operation of a one tonne submerged combustion pilot plant for the recovery of copper from anode furnace and converter slags is described and the effects of variables discussed. Using coal as reductant, copper levels of anode furnace slag were lowered to 1% or less, with batch times of approximately 120 minutes. Fluxing with limestone was required to produce a fluid slag at temperatures of 1200 - 1300¦C. For converter slags, reduction to 0.5% Cu or less was achieved in batch times of 35 minutes. The chemistry of the pyrometallurg- ical recovery of copper is briefly reviewed in relation.to copper recovery methods.

Jan 1, 1978

This paper summarises the performance of the gold exploration industry in the Western World since 1970, with particular emphasis on the period 1985 - 2003. It identifies the number and size of major (ie >1 million ounce) primary gold discoveries made over this period by location and type of company. Estimates are also made of the likely contribution from smaller discoveries down to 0.1 million ounces. It also assesses the overall trend in the percentage of grassroot discoveries that are converted into mines, and the time taken to get them into production. By comparing the discovery data against total exploration expenditures it is possible to determine the average unit cost of finding a major gold deposit. It is significant to note that the average unit cost per discovery and per ounce of resource has tripled over the last 30 years. An attempt is made to determine the overall economic value generated by the industry. This is based on a detailed analysis of the rates of return and the Net Present Values (NPVs) of 109 major gold projects. After including an adjustment for discoveries not modelled, the NPVs are compared against the total amount of money spent on exploration to determine the value-to-cost ratio for the industry. Based on historical spot gold prices and tax rules, it is found that the return on investment for gold exploration in the Western World over the period 1985 - 2003 was around five per cent real after-tax. The returns achieved in the US and Australia was significantly higher than that for Canada. The returns also appear to have declined in recent years. With regard to the relative performance of junior versus major companies, the paper estimates that the junior sector accounted for 30 - 40 per cent of the total exploration expenditure, and were was associated with 34 per cent of the total number of major deposits, 27 per cent of the contained ounces and 25 per cent of the economic value found.

Jan 1, 2004

The resource sector is conservative industry and people are resistant to change. The methods and procedures used to implement changes in process plants ultimately determine the success of such changes. The financial managers have a large say in where money is spent and the technical personnel must justify the cost and benefits for any expenditure. There are also others who believe it canÆt be done û æwe tried thatÆ. Implementing change needs a æChampionÆ who can assess the risks, plan, define the objectives and scope, set the goals, determine the key performance indicators (KPIs) and stay focused. This also requires preparing a budget and schedule and measuring against this. Contract management, reports and reviews are part of the implementation. Several case studies are given as examples of the implementation of process design changes to highlight the critical aspects involved.

Jan 1, 2009

By Walker V

The 'MAGNADET' to provide a safe enhanced protection extraneous currents, electricity and radiodetonator was designed electric detonator with against the effects of current leakage, static frequency energy.It has found a particular niche in shaft sinking operations and Mount Isa Mines initiated trials of the system in 1983 as part of the design work for the 3000/3500 orebody access shaft.Initial surface blasts indicated a number of significant advantages which were confirmed during the bench and concrete phase of the M37 shaft sink. The application of 'MAGNADETS' was later extended to the horadiam phase of the project.Details of the exploder capacity calculations for the various M37 round designs are included with the paper.

Jan 1, 1985

By I D. Hair

A numerical groundwater model was used to predict the nature of interactions between heavy mineral sands mining operations and the groundwater regime at North Stradbroke Island, Southeast Queensland. North Stradbroke Island is formed mainly of massive vegetated Cainozoic aged dune sands. Since the 1950s, a number of operations have mined rutile, zircon and ilmenite on North Stradbroke Island. In such mining operations, a dredge and an associated processing plant are floated in a pond either above or below the prime groundwater table The numerical model was based on the North Stradbroke Island Groundwater Management Model, developed in 2001 by the Department of Natural Resources and Mines (NR&M). This model was constructed using the modular, cell-centred, finite-difference groundwater flow model, MODFLOW, developed by the United States Geological Survey (USGS). The NR&M model was refined to improve model resolution and detail for simulating dredge mine paths. Of particular interest were: water table fluctuations induced by mining for the identification of slope stability risk; the optimisation of sand spear arrays supplying mine make-up water requirements; inflow and outflow rates to the dredge pond for overall mine water balance; and interactions with Eighteen Mile Swamp and water supply bores controlled by the Redland Shire Council (RSC). Depending on the water level in the dredge pond compared with the surrounding groundwater table, water either flows out of the dredge pond into the groundwater regime or from the groundwater system into the dredge pond. The MODFLOW river package (RIV) was utilised for the modelling study. Dredge pond movement was simulated using specialised software developed by Watermark Numerical Computing (WNC) to interpolate pond positions and map the dredge path to the model grid both spatially and temporally. As tailings placement affects the groundwater system through increased recharge, the MODFLOW recharge package (RCH) was utilised to simulate different recharge efficiencies. Long-term model predictions were made for the period from July 2002 to May 2021. Results of the modelling showed that exchanges of flow between mining operations and the groundwater regime could be effectively managed. The study provided valuable information which was used to develop an appropriate mine water management plan.

Jan 1, 2003

The writer had the pleasure of several months' laboratory tests on a metallurgical process for copper ores devised by Mr. W. H. Corbould, Consulting Engineer, North Queensland. Mr. Corbould's research work in this direction commenced somesix years ago, and he eventually succeeded in obtaining a good extraction of copper and a resulting solution practically free from iron and other impurities. The commercial operation of the process was investigated and special machines with novel features were designed. OUTLINE OF THE PROCESS.The process described in detail in the following pages, required for successful application that the ores contain at least the minimum ratio of sulphur to copper, consistent with the production of sulphadising roasting conditions.

Jan 1, 1921

By Will D. P

A 328 m, 2.4 m diameter raise-bored shaft has been equipped with a modular ladderway system to provide a second means of egress from Aberfoyle's Hellyer Mine in Tasmania. The modular ladderway consists of platforms, ladders and service pipes assembled at the surface and progressively lowered down the shaft. This system provides a rapid, safe and economical non-entry approach to equipping a shaft. The modular construction and single suspension allows for future extension or for reuse in another shaft.

Jan 1, 1988

Modelling of Synergistic Effect of Cyanex 302 and D2EHPA in Zinc Solvent Extraction A comprehensive model is presented to predict the synergistic effect of D2EHPA and Cyanex 302 on co-extraction of zinc and manganese. The experimental results indicated that pH, temperature and the extractants ratio have strong effects on the extraction process. Correlations were proposed to predict the distribution coefficient of zinc and manganese between two phases at different conditions by multiple linear regression. The correlations were simplified by eliminating less important terms by analysis of variance. Optimum conditions (ie pH, temperature, extractants ratio and aqueous to oil phase volumetric ratio) for obtaining maximum separation of zinc from manganese at different zinc concentrations and number of extraction stages were determined. For finding the optimum condition genetic algorithm was used. Comparison the model estimations and the experimental data show that the presented model has good ability to predict the behaviours of zinc extraction system over Cyanex 302 and D2EHPA.

Sep 13, 2010

By Borshoff J, Von Pechmann E

The uranium mineralization in the White's East area of The Embayment is hosted by Lower Proterozoic schists of the Masson Formation which have undergone polyphase de- formation and upper greenschist metamorphism. Significant mineralization is also present in apatite rocks. The ore zones occur near an unconformity with overlying Middle Proterozoic sandstone and breccia conglomerate. Kink breccias and fracture systems related to post Middle Proterozoic reverse faults are the con- trols for mineralizing fluid migration. Pitchblende is the main uranium mineral and it occurs as fine disseminated grains, fibrous webs, clusters composed of botryoidal aggregates and locally as veins. Two genera- tions of uranium mineralization are present. The first generation (pitchblende I) occurs as fine grained inclusions within chlorite II, and the second (pitchblende II) as hydraulic fracture networks and massive veins intimately associated with sericite-hematite-chlorite III. Two hydrothermal alteration phases have affected both Lower Proterozoic and Middle Proterozoic sequences. The most extensive alteration mineral is chlorite, of which a number of varieties has been identified. Mg-rich chlorites are generally associated with the first phase alteration assemblages and are commonly replaced by hematite, seri- cite and Mg-Fe chlorites in massive pitch- blende zones. Other alteration minerals in- clude tourmaline, apatite, talc, quartz, magnesite, graphite, pyrite and rutile.

Jan 1, 1984

A real Dorothy Dix title has been selec- ted for this paper. It has the advantage, however, of being capable of being interpreted in many different ways and hence I can select my own approach. You probably are thinking that this topic would be more appropriately handled by an Accountant. I wish to make it clear at the outset that I am not skilled in the sometimes mysterious ways of Accountants - likewise that profession frequently has difficulty in pinning down economists. We have our own strange ideas about profits, marginal efficiencies, cost/benefit analysis etc. What follows is in the main a mixture of two disciplines, probably in a form that few of the purists from either side would accept. Nor do I expect the reader to accept my own prejudices. The paper is designed to stimulate thought and discussion'on the subject. Emotive words such as "profit" and "loss" make for wide differences of opinion. At the time of writing there is a surprising degree of acceptance of the viewpoint that profits in Australia are too low and one is tempted to make this point of near agreement a starting Point.

Jan 1, 1975

By Tronson K

Improvements in technology do not necessarily lead to higher profits: the benefit of lower costs can be captured by coal buyers, governments and workforce rather than by the colliery operators. The economic impact of longwall mining in Australia has been critically assessed to provide lessons for the future. For a variety of reasons, companies investing in longwall equipment in the past five years have generally not achieved an adequate return on the funds invested. The effect of technological innovation must be examined in the light of competitive forces operating in the market. Projections of cost reduction trends in the coal industry have been applied to a world cost model to provide a picture of the coal industry in the year 2000.

Jan 1, 1988

By A Crawford, P Manton

Telfer is a gold/copper operation, currently operating one open pit mine and one underground mine. The ore processing plant consists of two parallel trains involving semi-autogenous mill, ball mill and crusher (SABC) grinding, flotation and leaching. Due to receiving relatively high grade underground ore for over half of its total feed, Train 1 frequently experienced cleaning circuit overloading during high production periods. This resulted in losses in recovery and ineffective concentrate upgrade. As a quick and simple solution, the Train 1 copper flotation circuit was reconfigured to send concentrate from the first two rougher cells directly to the final concentrate and return the cleaner scavenger tailings to the third rougher cell. These modifications have resulted in a 1.4 per cent increase in plant copper recovery with no change in final concentrate grade. Preliminary results also indicate gold recovery has increased by more than 1 per cent since the circuit reconfiguration. Other benefits include less spillage, more friendly circuit to operate and a more consistent metallurgical performance. Focus for the next phase of optimisation is on concentrate upgrade. A number of opportunities have been identified and are currently being investigated, including staged reagent addition, single stage cleaning of the first two copper rougher concentrates, regrinding of the remaining copper rougher concentrate prior to cleaning and process control based on a machine vision system.

Jan 1, 2009

By Bensley C. N

In June 1995, BHP announced that it would build a Hot Briquetted Iron (HBI) plant and associated beneficiation, materials handling and infrastructure facilities at Port Hedland, Western Australia. This plant, the first direct reduction plant in Australia, will convert beneficiated iron ore fines into metallic iron for briquetting into HBI. The reduction plant will be based on the FINMET fluid bed technology jointly developed by Fior de Venezuela and Voest-Alpine Industrienlagenbau. Electric Arc Furnace steelmakers in the Asia Pacific region will be the principal customers for the product. This paper presents an overview of the facilities to be constructed by the project as well as discussing some particular technology and design engineering issues associated with the project.

Jan 1, 1996