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By Brant BA, Lewandowski R, Trendle M, Haughton D

There is a vast amount of geotechnical data, which can be obtained during exploration programs at new and existing mine sites. Additional information on the performance of the in-situ rock mass can be obtained from bore cores, which are usually only geologically logged and then stored. A computer based data management system for storage and retrieval of geotechnical data has been developed to access and manipulate such data.

Jan 1, 1983

By Leggate J

In the past many coal mining projects commenced without any consideration being given to eventual site rehabilitation. Now that site rehabilitation is assuming greater importance with changing community expectations, and standards are becoming less negotiable, it cannot be ignored in either the development of mine working plans or economic models. The "unspecified" rehabilitation measures associated with many existing projects will be the subject of debate for some time to come yet. It would be wise to plan for the future. Once an agreeed standard of rehabilitation is accepted, good management involves considering practices which will facilitate eventual rehabilitation at least cost. Without planning for rehabilitation, many mines have adopted practices which are likely to result in very expensive rehabilitation measures and impact significantly on the overall profitability of the ventures. With adequate planning, procedures can be developed which achieve the same short term goals without significantly effecting cash flow but with very significant impacts on the final rehabilitation cost. This paper looks at the disposal of tailings and overburden in the coal mining process. The industry has in the past had an obvious preference for the "perceived" cheaper procedures for waste management such as wet disposal of tailings and high dumping of overburden. There are alternatives. The paper discusses the principles which should be incorporated into tailings and overburden disposal systems and identifies viable alternatives.

Jan 1, 1991

Blasting is at first sight a simple operation. Blastholes are drilled in a suitable pattern, primed, charged with explosives, stemmed and finally the blastholes are connected together to give the appro- priate initiation sequence. In practice the action of the explosive takes place in the interior of an opaque rock mass and only the external faces of the rock mass to be blasted can be easily observed. The mechanisms of blasting cannot be observed directly and must be inferred from observations of the free face and meas- urements of particle movement made by sensors grouted into holes in the rock. Explosives react very rapidly, in some microse- conds and any instrumentation of a blast must have an appro- priate response time. In many mines several rock types can be encountered during production. Several different methods of blasting may be necessary to cope with changes in rock types espe- cially if weak rocks are found in the final limits. This also makes it difficult to be sure of getting a large enough volume of rock to perform a series of reproducible experiments. While there appears to be agreement on the mechanism of blasting it is unlikely that a detailed understanding of how all the variables that can be encountered in practice affect blasting. The ease of assessment of the results of blasting depends on the criteria used. It is easy to isolate, measure and count over- size boulders. It is however difficult and costly to get a complete fragment size distribution. Methods used to assess blasting can vary significantly from site to site and the ways in which data are collected, presented and analysed will vary making compari- son of blasts at several locations very difficult. The definition of an optimum blast can also vary with the type of blasting. The muck-pile profile and fragmentation will be different for a dragline to that for a truck and shovel operation. In order to be able to assess blasting the mechanism has to be understood. Th rock and explosive properties considered rele- vant to blasting can then be determined. This paper discusses the generally accepted mechanism of blasting. The on-site observa- tions to assess blasting are-then listed. The mechanism of blast- ing can also be modelled and the use of modelling to optimize hlaetina ie thPn Aiernccarl

Jan 1, 1988

By Koppe JC, Strieder AJ

The Rivera Crystalline Island (RCI) is an erosional window of the intracontinental Parana Basin that outcrops in the Rivera Department, north of Uruguay. RCI is made up mainly by Precambrian granites, metasediments and granite-gneisses. This island is crosscut by a dextral transcurrent shear zone system, the Rivera Shear System (RSS). The bulk strain ellipsoid was defined by previous work and has allowed the evaluation of shear dynamics. The geometry of the shear system is made up of two shear directions: E-W (P-shear), which turn right to NW-SE direction (R-shear), leading to the development of extensional bends. The shear zone system was developed in brittle-ductile to brittle regimes, under temperature conditions compatible with greenschist facies metamorphism. The shear zones are marked by an intensive fracture cleavage development. Mylonites develop only in narrow, discontinuous higher strain zones. Internally, the shear zones are dominated by intrusive rocks, mainly granites, dacites and diorites. Hydrothermal alteration has been developed in several areas.The economic significance of RCI is given by several small gold deposits, which have been exploited since 1869. One major new gold mine is under development, the San Gregorio Gold Mine. This gold deposit is locally controlled by a dilatant site where R-shear turns right to P-shear. Mine lithologies were deeply altered by hydrothermal fluids in the dilatant structure. This work presents the lineament-structural analysis carried out to identify similar structural patterns in all RCI sites favourable to host other gold deposits. The exploration program also considered remote sensing, geology, geophysical and geochemical survey.

Jan 1, 1997

By G Kennewell

At 11 am Monday 8 September 1997, the successful detonation of the 5/9 Mass Blast at Pasminco - Elura was signified by the subsiding of æMt KevinÆ (a 15 m high earth fill mound). The blast was in response to earlier mine subsidence, which holed through to the surface affecting future stability of underground workings. The blast was a first for Elura which fires small tonnages regularly to avoid rapid oxidation of the ore. This paper discusses the strategy and the considerable planning that went into EluraÆs first blast of this magnitude in order to succeed first time round.

Jan 1, 1999

It is no longer adequate when starting a new mine to simply select the best equipment. Today's competitive international commodity markets demand superior efficiency which requires systematic involvement of people in continual improvement of production and commercial processes. True Total Quality of Management (True TQM) principles provide an operating philosophy for maximising productivity and minimising unit costs of output. The presentation will show the practical and successful use of these principles. This paper will introduce the case study and provide background material on True TQM.

Jan 1, 1995

It is no longer adequate when starting a new mine to simply select the best equipment. Today's competitive international commodity markets demand superior efficiency which requires systematic involvement of people in continual improvement of production and commercial processes. True Total Quality of Management (True TQM) principles provide an operating philosophy for maximising productivity and minimising unit costs of output. The presentation will show the practical and successful use of these principles. This paper will introduce the case study and provide background material on True TQM.

Jan 1, 1995

By Tack K

During its 28-year life the MHD ISP smelter has gone through two phases, each of about a dozen years. The first phase was a learning one; in the second phase the lessons were applied and throughput and production rose strongly. Early experience revealed the robustness and the flexibility of the Imperial Smelting Process. The experience was demonstrated by strong increases in the throughput of mixed lead-zinc concentrates and of secondary (oxide) zinc materials. Purchased material quantities rose from 175 000 tonnes/year to 200 000. The required capacity increase of the IS furnace to smelt the higher throughput was achieved by relatively minor modifications; for instance a change to the internal furnace profile gained an extra two square metres in cross sectional area. The furnace hearth area has remained practically unchanged over its entire history. The paper concludes that there is still more potential to be drawn from the process and MHD intends to sustain raw material input at a new level of 240 000 tonnes/year. However, this rate will have to be achieved under the imposition of more stringent environmental and product quality standards than ever before.

Jan 1, 1993

By Watters R

Modem open cut and underground mining in the tropics inevitably expose partially weathered and unweathered rocks to oxygen and water, leading to weathering and the release of solutes and often acidity as well. Historical monitoring data can demonstrate these phenomena. Three case studies from open cut mines in the north of the Northern Territory illustrate the deterioration in quality of pond water receiving drainage from waste rock dumps. The potential for deterioration of water quality was not recognised in many mine Environmental Impact Statements prepared and accepted in the 1980s. The examples documented indicate the importance of adequately planning for this near inevitable process. Retrofitting a mine water management system to 'no' or minimal release can be very difficult and expensive, and may not be feasible, leading to downstream pollution. The characterisation of acid and solute production potential of ore and waste rock, and improved dumping strategies and water management are very important to minimise the environmental impact of mining in the tropics.

Jan 1, 1994

By Grady B. V O, Cavell K. J, Ault A. R, Newman O. M G, Malcolm J. McPhersqn

Cyclic voltammetry (CV) has been evaluated as a technique for monitoring the quality of an industrial zinc sulphate electrolyte. The basis of the method involves measuring a change in the polarisation of the zinc nucleation reaction at an aluminium surface and relating this to the impurity content and/or the overall quality of the electrolyte. Specifically, the technique aims to be able to indicate and quantify detrimental synergism between impurity elements, something which traditional analytical techniques are incapable of providing. The technique has found some success with regard to monitoring glue additions in a range of metal electrolytes. It has been found that investigations by a number of workers over the past 15 years have produced variable and often misleading results due to the inadvertent use of commercial purity aluminium working electrodes. It has been shown that impurity elements in the working electrode can give rise to a range of responses that are not obtained when pure aluminium is used and that the response is variable due to the lack of surface homogeneity of commercial purity aluminium electrodes. Furthermore, it was demonstrated that previous detection limits reported in the literature were based on the presence of additional peaks in the cathodic scan and not polarisation effects. The results of this study have shown that when a pure aluminium working electrode was used, the method was incapable of detecting any change in polarisation for an electrolyte containing three common impurities (Co, Ni and Ge), at concentrations that would significantly reduce optimum electrolytic performance. A range of methods was tried to sensitise the technique, including raising the temperature and acidity, and adding antimony in order to induce some synergism. In all cases the polarisation response was unchanged. Consequently, apart from the commercialised application for monitoring additions of antimony and levelling agents such as glue, CV has very limited application as an electrolyte screening technique.

Jan 1, 1993

By A Grice

AMC has completed a number of backfill options studies, including several in recent years for large, three-dimensional orebodies involving total extraction by longhole open stoping with backfill. This has led to the development of a thorough review methodology that assists in the selection of the most appropriate backfill system and the most economic mixes to achieve the required performance. A recently developed design tool has simplified the calculation of backfill strengths for various exposure dimensions and automatically determines strengths incrementally over the height of a stope. Using a generic orebody with a plan dimension of 120 m wide by 360 m long, several different stoping layouts have been analysed to determine the effect of stope dimensions and sequencing on backfill strength requirements. This has been done for stope heights from 50 m to 300 m, in 50 m increments. The required strengths have been calculated in slices and summarised for each stope in four equal layers. The average strength requirement for each layout at each stope height has been compared graphically. For all stope heights, a panel stope layout that minimises the proportion of primary stopes results in a lower average strength requirement than grid layouts on a checkerboard pattern. However, for very high stopes, smaller plan dimensions become more economic. The increase in required strength with stope height is non-linear, making taller stopes potentially more attractive. The main cost factor in most backfills is the rate of binder addition, which is closely related to the strength required. By choosing a layout that minimises the backfill strength requirement, significant savings in binder addition rates and overall costs can be achieved. These must, of course, be weighed against other factors to determine the optimum stoping layout and backfill system.

Jan 1, 2000

By Fair A, Oxenford J

Syncrude Canada Ltd operates one of the largest open pit mines in the world at Fort McMurray in northern Alberta, Canada. In 1993, Syncrude mined and processed 131.2 Mt of oil sands to produce 67.0 MBbls of synthetic crude oil (SCO). This represents approximately 13 per cent of Canada's crude oil requirements. In addition to the oil sand mined, Syncrude moved approximately 96 Mt of overburden ahead of the mining operation in 1993. Since start-up in 1978, Syncrude has had outstanding success in improving the safety and reliability of its operation. Much of this success has been achieved by reducing risk through the application of new and improved technology. This improved safety and reliability has resulted in, among other things, very significant improvements in operating costs and profitability. This paper discusses some of the technology applications that have been introduced at Syncrude to reduce risks to people, equipment, operations and the environment. Three specific examples will be discussed in detail to demonstrate how reductions in risk have greatly improved the operation.

Jan 1, 1994

By Rose CW

Typical rehabilitation programmes for spoil piles and waste dumps in open cut coal mines involve the spreading of topsoil to assist vegetation growth. In the early years of rehabilitation before a protective vegetation cover has been established, this topsoil is susceptible to erosion during rainfall events. Since the long term success of rehabil- itation procedures is sensitive to adequate topsoil maintenance and since, on many mine sites, topsoil is a scarce resource, erosion losses of topsoil (particularly once fert- ilised) can severely restrict rehabilitation Measures.

Jan 1, 1983

By S Walters

The emerging discipline of ‘geometallurgy’ is not new but is becoming increasingly recognised as a discrete and high-value activity. Geometallurgy involves a quantified and spatially constrained approach to ore characterisation in terms of relationships to critical processing performance behaviours. A key outcome is enhanced economic optimisation of mining and improved risk management tools.Industry recognition of the need for large-scale, integrated research to support this emerging area resulted in commencement of a major ongoing initiative in mid-2005. The AMIRA International P843 ‘GeMIII’ project (Geometallurgical Mapping and Mine Modelling) is a cross-discipline collaboration involving a number of world-class research organisations supported by over 20 industry sponsors.The project is delivering integrated tools and methods which link intrinsic rock characteristics to prediction of mineral processing performance. These indices must be capable of spatial distribution in 3D resource models and incorporation into mine planning and optimisation. A key aspect is provision of new cost-effective tools and methods which can provide the large numbers of measured and estimated data points required to undertake effective modelling and spatial distribution. The integrated methodology and enabling technologies being developed through the ongoing AMIRA GeMIII project are outlined, together with implications for supporting industry best practice.

Sep 5, 2011

By C Wu, H Chen

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.The Halasu porphyry copper belt, located in the East Junggar basin bounded by Chinese Altay to the north and the Tianshan mountains to the south in the Central Asian Orogenic Belt, is one of the major porphyry copper belts in Xinjiang province, north-west China. Combined with previous studies in this area, the magmatism can be divided into three periods: pre-mineralisation activity of 390 Ma syn-mineralisation activity of 380–370 Ma post-mineralisation activity of 360–330 Ma.Through the comparison of zircon chemistry from ore-bearing and barren syn-mineralisation intrusions, negative correlation was identified between Ti-in-zircon temperatures and oxygen fugacity, corresponding to the fact that late-stage syn-mineralisation granitoids contain high water content, high oxygen fugacity and low temperatures with higher mineralisation potential. In addition, the relative low initial 87Sr/86Sr ratios, high eHf(t) and eNd(t) values and mantle Pb isotope characteristics in this study support that the magma forming these intrusions was probably derived from juvenile crust generated during subduction-accretionary processes.CITATION:Wu, C and Chen, H, 2015. Zircon trace elements and Sr-Nd-Pb-Hf isotope systematic of the Halasu porphyry Cu belt, north-east Xinjiang, China, in Proceedings PACRIM 2015 Congress, pp 637–640 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By S T. Jarvis

Colliery spoil is the major constituent of colliery spoil ærockpasteÆ which has been used to infill abandoned limestone mines in the West Midlands of England since the early-1980s. The other constituents of rockpaste are pulverised fuel ash, lime and water. A key property of the rockpaste is its ability to flow within the mine workings over considerable distances before setting. This paper describes the work carried out to identify suitable sites as sources of colliery spoil for making rockpaste and goes onto consider the flow properties of the material and the monitoring methods used on-site. A full-scale trial comprising infilling a 6600 m3 section of an abandoned mine was conducted prior to the infilling of the Littleton Street Mine which had a volume of about 500 000 m3. As well as describing the methods used for monitoring the movement of rockpaste material, a description is also given of a dip-meter developed specifically for the purpose of measuring the level of paste in the mine. This paper shows how a colliery spoil based paste has been successfully used for infilling abandoned mine workings. The monitoring systems developed for use in the two case studies presented in this paper are now being used extensively for infilling other abandoned mine workings. To-date over 11 mines with a total volume exceeding two million cubic metres have been backfilled.

Jan 1, 1998

By Dharmappa HB, Sivakumar M

This paper is concerned with two case histories of wastewater quality management in underground coal mines in the Illawarra region. The first investigation briefly presents an analysis of mine water discharge having an extremely high concentration of suspended solids and consistently high barium concentrations, averaging, 14.4 mg/I Barium, over the sampling period. A laboratory study of chemical precipitation processes has indicated that about 91% of barium could be removed by using ferric sulphate and lime. On the basis of the information obtained from the environmental audit process an alternative water treatment and reuse system incorporating 51% reduction in the water consumption with 32% less off-site discharge has been suggested (Thomas, 1995).The second case history is concerned with the storm water management at a mine situated in the Illawarra escarpment where only 20% of the wastewater generated in the colliery is discharged off-site. Computer modelling of the storm water system showed that 75% of the clean runoff becomes contaminated through poor management practices and causes the process wastewater treatment system to fail in wet weather. Suggested improvements include relatively simple alteration to the coal wash filtration dams which are expected to reduce the periods of inefficient operation of these dams by 95%. The use of storm water diversion channels and detention basins can reduce the overflow volumes by 70 - 100 % for a ten year ARI (Average Recurrence Interval) storm event (Wingrove 1996).

Jan 1, 1998

By Henderson N, Schaap H

In large companies with mining operations spread over multiple sites, it is essential that consistency between sites is maintained in preparing and classifying resource and reserve estimates. The endorsement by The AusLMM and AMIC of the "Australasian Code for Reporting of Identified Mineral Resources and Ore Reserves" and the subsequent incorporation of reference to the code into the ASX listing rules for mining companies has provided a basis for the consistent classification of resources and reserves. However, compliance with other criteria more or less stringent than the Australasian Code can present some reporting difficulties. Examples include listing requirements for foreign stock exchanges, particular Acts of Parliament that may apply to individual leases, constraints imposed by individual companies on their own leases, and ultimately, reserves for short, medium and long term planning. Confusion can arise when any two or more sets of reserves for the same lease are compared.. To alleviate this confusion, a standardised procedure was developed for the calculation and classification of coal resources and reserves. The procedure which is geostatistically based incorporates a technique called "Irregular Block Kriging" where specific mining blocks are directly kriged. The procedure has enabled those engineers and geologists with only a basic understanding of geostatistics to apply the technique and not feel hampered by some of the complex mathematics which in the past has tended to inhibit and overcomplicate the use of geostatistics. The procedure has resulted in "cleaner" data bases and hence more reliable reserve estimates.

Jan 1, 1990

By H M. A Ilyas, M Yahyaei, S Amari, M Darestani

Tailings are generally deposited on or near to the mine sites, occupying the site area, and being an economic burden for mining companies. Tailings can cause several environmental impacts, such as leaking toxic substances and contaminating underground water, emitting greenhouse gases, and damaging natural bodies and wildlife. Geopolymerisation of mine waste effectively transforms mine waste into more valuable, environmentally friendly products. Geopolymers are inorganic aluminosilicate materials that are widely applied in the construction industry (Araya, Kraslawski and Cisternas, 2020). The high performance and the low-CO2 emission of geopolymers make this type of material potentially more desirable than ordinary cement, given that manufacturing one ton of traditional cement generates approximately 0.8 tons of CO2. This process is seen as a promising method for repurposing tailings and reducing the environmental impact of mining waste. However, the environmental impact of geopolymer production is not sufficiently comprehended (Mazzinghy et al, 2022). Moreover, geopolymerisation of mine waste can offer several economic benefits, including reduced waste management costs (Amari et al, 2019; He et al, 2022), reduced raw material costs, and potentially lower production costs. However, there are several challenges that need to be addressed to ensure the economic feasibility of the process. This study aims to demonstrate the potential environmental impacts of geopolymer concrete produced using mine wastes and industrial by-products such as blast furnace slag (BFS). For this, a comparative cradle-to-gate life cycle assessment (LCA) methodology was conducted on different geopolymer mix designs, and the greenhouse gas (GHG) emissions results were compared to the ordinary cement. LCA can be used to evaluate the environmental impact of geopolymerisation of mine wastes in various ways. One important impact category is GHG gas emissions, which contribute to climate change and is the focus of this study. Another aim of this study is to evaluate the economic feasibility of the geopolymerisation of mine wastes via economic analysis (EA) to identify the key economic factors and trade-offs associated with repurposing mine wastes through geopolymerisation.

Aug 2, 2023

By W F. Bawden, J T. Paynter

This investigation involves laboratory testing and stability analysis of paste fill at the Golden Giant Mine. Site-cast samples are tested in unconfined, confined, and consolidated-undrained triaxial compression. Pore pressures during shear and consolidation characteristics are measured to determine both drained and undrained shear strength parameters and assess the potential for undrained loading. Liquefaction potential is also considered. A limit equilibrium solution is used to obtain factors of safety against failure of the fill during mining of adjacent stopes.

Jan 1, 1998