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By Brimblecombe P

Morwell Open Cut is a continuous mining operation employing 5 buck- etwheel excavators, I bucket chain excavator and 54 conveyors. The combined bunkering capacity at both client Power Stations represents less than 12 hours maximum coal demand. This creates an extremely dynamic operating environment, which is further complicated with significant variations in both excavating and transportation plant capabilities. To achieve set objectives, including- I adequate reserves, 2 coal supply reliability, 3 cyclic plant maintenance, 4 minimal cost of coal, scheduling of the operation requires constant monitoring and reappraisal. Investigations are in progress to develop a computer based scheduling tool capable of simulating the complex operating environment. A review of computer scheduling packages currently available within the State Electricity Commission of Victoria has found limitations making most unsuitable for the task. The type of package found to be most suited is a knowledge based system ('Expert System')capable of operating within a set of rules defined by the user. Work is proceeding on the development of a knowledge base to test the effectiveness of Personal Computer based `Expert Systems'.

Jan 1, 1989

Structural geological information is widely used at the Mt Whaleback Mine, Newman, WA. Recent improvements in the structural understanding of Mt Whaleback are providing a very cost-effective way of reducing geological risk, improving the economics of mining, optimising pit design and addressing safety problems. The structure of the Mt Whaleback orebody is highly complex and has a significant influence not only on iron ore genesis but also on pit wall stability. A team approach between the Structural Geology and Geomechanics Groups has been providing excellent results to reduce geological risk at Mt Whaleback.

Jan 1, 1994

An analysis of pumping figures suggests that there are two distinct styles of water inflow patterns in Zambia's mines. Carbonate hosted orebodies (Kabwe and Nampundwe) display a characteristic seasonal variation in water inflow with peak pumping showing a short time lag with respect to the rainfall pattern. Aquifer characteristics are controlled by secondary, weathering enhanced, near surface phenomena. Non-carbonate hosted orebodies such as those of the Copperbelt (Konkola and Nkana) occur in successions of highly variable lithology and consequently there are stacked aquifers of variable character. Inflow of water does not display seasonal variation. The major factors affecting the amount of inflow are the structural setting, the geometry of the orebody and the local lithostratigraphy. Thus the Konkola orebodies which occur in a saddle shaped open ended basin result in what is probably the wettest mine in the world, pumping some 376,000 cubic metres of water a day.

Jan 1, 1988

By J C. Small

Time-dependent deformation occurs when geo-materials are under an applied load; this may lead to additional deflection of a tunnel structure and the stress redistribution in the surrounding rock, shotcrete lining and rock bolt support system over time. A better understanding of this creep behaviour can improve the reliability of design, construction and maintenance of tunnels. Hence, the present investigation was carried out on the time-dependent properties of rock, shotcrete and the combined tunnel support system. Tunnels constructed in different ground conditions were modelled. The closure changes of the tunnel with time and the redistribution of stress in the surrounding rock, shotcrete lining and rock bolts due to the creep deformation were analysed. Results of the present analysis were compared with the results from the commercial program ABAQUS.

Jan 1, 2008

By Miles M. J, Sandy D. A

It has long been known that drilling and blasting operations have a direct influence over productivity and costs of subsequent operations. If mine management is to effectively optimise blasting operations, good information is required on the operating costs of each of the affected operations, together with knowledge of how they are influenced by blasting. In practice it is not possible to do enough repeats of a full scale production blasting experiment to make a statistically significant analysis of the results. By monitoring each blast and subsequent operations in as much detail as possible, enough data will be available to effectively measure the effect of blasting on costs. This gives management an insight into the blast performance and is the first step towards optimisation. An Integrated Blast-related Cost Reporting System has been developed at the Rossing Mine Open Pit, which calculates the total mining cost for each blast. In assessing the total mining cost for each blast, use was made of an.integrated planning and management information system to collect relevant production variables, current operating costs and survey data. An automatic image analysis system was employed to measure the fragmentation of the blasted material in the back of haul trucks. A shovel monitoring system is also under development for use in assessing the muckpile diggability and, in conjunction with an appraisal of shovel component reliability, to estimate the maintenance cost under various digging conditions.

Jan 1, 1990

Deposits of chromite are in associated with ophiolite complexes in Papua New Guinea. No deposits which are currently exploitable have been recognised, but large resources that may be economic in the future are present at Ramu area and on the Morobe coast. These are contained either in laterites or in sediments derived from ultramafic members of the ophiolites. There are possibilities of establishing further resources either in similar settings or associated with ultramafic members of alkali intrusive Complexes.

Jan 1, 1987

The BLEG (Bulk Leach Extractable Gold) technique is a semiquantitative measure of cyanide extractable gold contained in a sample. A 5kg sample is leached in cyanide solution for 24 hours and gold is precipitated out of the pregnant solution using zinc and assayed by AAS. The detection limit is reported as ppb (parts per billion). Telfer is located 1300km north north-east from Perth in the Great Sandy Desert. The climate is one of hot summers with irregular rainfall and mild winters. A large portion of the area is covered by aeolian sand and seif dunes with poorly developed drainage, rare outcrop; topographic relief is a maximum of 96m. Poor outcrop and poorly developed drainage render conventional stream sediment sampling and soil geochemistry inadequate. Therefore a technique providing a minimum number of samples with maximum accuracy and sensitivity was needed. Consequently BLEG orientation surveys were conducted over the Telfer Mine area in 1983, 1984 and 1985.

Jan 1, 1988

By Isaac AK

The combination of shot-firing and stage loader, and a prop and bar support system is an accepted drivage method. The support configuration is based on the final prop density, and assumes relitively uniform load sharing between the props. During the development of a longwall faceline at a medium depth (approximately 600m) British coal mine using such a drivage method, a fall occured overnight, effectively closing approximately 40m of the drivage. The severity and speed of the fall prompted an investigation into the performance of the temporary support system installed prior to chock installation. This paper deals with the investigation which disclosed some major contributory factors towards loss of strata control.

Jan 1, 1986

With mining development on hold and other underground works in a slowdown, the develop- ment of nuclear waste repositories takes center stage on the American rock engineering scene. Three repositories for commercial spent fuel -- in salt, tuff, and basalt -- are in the phase of site characterization and conceptual design, and one pilot project for defense high-level waste in salt is under construction. A repository design for crystal line rock has recently been postponed. Because of strict quality assurance requirements throughout design and construc- tion, and because of the need to predict and ascertain in advance the satisfactory perfor- mance of the underground openings, much intellectual energy has been expended to analyze underground openings in the unusual circumstances of the repository environment. In the long term, these efforts will lead to an improved understanding of rock behavior and improved methods of underground analysis and design. For the shorter term, a formalized ground control plan was developed, the princi- ples of which may be applied to other types of projects. This paper summarizes the status of underground design and construction for nuclear waste repositories and presents some details of the ground control plan and its individual elements.

Jan 1, 1987

Lightweight polymer grids have recently been introduced to the mining industry. They are currently being used for roof and rib control, longwall shield recovery, safety guarding or barricade, highwall screening, internal reinforcement of gunnite/shotcrete applications, sub-base reinforcement, construction of steepened slopes, retaining walls, mine reclamation (i.e. erosion control, turf reinforcement), and in numerous mining waste related projects. These polymer mining grids utilize a strong, lightweight polymer, usually special grades of polypropylene or polyethylene. High tensile strengths are achieved by molecular orientation of these polymers in the manufacturing process. The first step in the manufacturing process is to extrude the polymers into thick continuous sheets. These sheets are then punched, and drawn into open grid structures. Aperture size and configuration are controlled by the geometry of the punched hole and the degree to which the grids are stretched. The drawing process is the key to the molecular orientation required for the tensile strengths. These long chain polymer molecules in their natural state have a random orientation. When stretched, the molecules are pulled into a parallel alignment, thus creating a lightweight product with tensile strength comparable to Steel.

Jan 1, 1992

An effective production control system should maximise recovery of economic material from the resource. To do this, internal waste must be accurately delineated and efficiently removed. Achieving this is most difficult in low grade blocks just above and just below the cut off grade, where ore:waste separation follows assay or statistical, rather than geological boundaries. Difficulties arise from sampling errors, configuration of the economic mineralisation, and local variations in geology. Mine bench parameters and mining equipment size apply further constraints to the actual field separation of the ore from the waste. At BCL, management of the resource starts with an effective orebody model for planning, scheduling and ore:waste prediction. Ore production from each mining location is reconciled with concentrator tonnage and grade, and the reconciled grades are compared with the planning orebody model to highlight any Differences.

Jan 1, 1986

Recent work on computerised mineral resource databases at the Institute of Geological and Nuclear Sciences Limited has concentrated on the development of the GERM, REGCHEM, and MINLIT databases, and their integration in a Geographic Information System using MapInfo software on an IBM-compatible microcomputer local area network. GERM (GEological Resource Map) is a mineral deposit inventory with national coverage and more than 10 300 entries. REGCHEM (REGional Exploration GeoCHEMistry) is a database of stream sediment analyses from open-file mining company reports, containing more than 14 000 sample sites from the Coromandel and west Nelson regions. MINLIT (MINeral LITerature bibliography) is an annotated bibliography of literature on topics relating to the exploration and geology of mineral deposits in New Zealand, and includes more than 5000 entries for published books and papers, and unpublished mining company reports, university theses, and government reports. Master sets of GERM and MINLIT continue to be maintained on a VAX mainframe network but REGCHEM is operated only in the PC environment using the Microsoft ACCESS database management system software.

Jan 1, 1993

By J Shillabeer

Paste backfill has been adopted by many underground mines in North America and a growing number elsewhere. Paste offers a number of advantages. This paper suggests wider applications of paste technology to surface tailings disposal and water management. Advantages include improved overall stability, potentially easier permitting, smaller water inventory and earlier reclamation. It may be feasible to use the same plant to prepare backfill and to dispose of surplus tailings. Example cost models are given to illustrate potential applications.

Jan 1, 1998

By Ho D, Yang J

The ready availability of powerful desktop workstations, which combine 3D real-time graphics and processing speed better than that of supercomputers of a few years ago, now allows the cost-effective solution of real world geomechanics and underground mining strength simulations. The inclusion of geotechnical factors such as rock joints and porous flow on strength and stability are discussed together with the range of available deformation and failure models for soil, rock and concrete. This paper describes the capabilities provided by finite element graphics and analysis software for modelling and sequential investigation of both excavation and lining, or rock bolting, construction sequences. Examples of the use of finite element models in mining are also included in the paper, together with a discussion of the required people, software and computer hardware resources required to achieve timely and productive results.

Jan 1, 1995

By Kristiansen J

A series of laboratory blasting and ball mill grinding tests have been done on four different types of hard and competent rocks. The results show that exposing these rock types to a higher level of explosive energy will enhance their grindability. True blasting optimisation should therefore look at the whole comminution process from solid rock to a marketable product.

Jan 1, 1995

The coal basins that formed near the margin of Permian Australia were comparable in size with the Appalachian coalfields and with the European fields between Wales and Poland. They formed on the foreland side of a growing orogen in a system of linked transform basins formed by transtension on strike-slip faults. They were terminated and compressed when the Gympie volcanic arc was accreted to the orogen. Another huge system of Permian coal basins extending far inland from the Permian coast was also terminated when the Gympie Terrane was Accreted.

Jan 1, 1987

The microstructures exhibited by ilmenite in its association with other oxide minerals have been the subject of a number of papers, the most comprehensive of which is that by Ramdohr. The following observations in some degree extend his conclusions. They are based upon a study of about sixty specimens of "massive" ilmenite and titaniferous ores from a number of wIdely 'scattered Australian localities. Specimens of this character proved much rarer than was expected. The collection was gathered together through the generous aid of the University Geological Departments, Geological Surveys, and Natural History Museums of the several States of the Commonwealth, all of which contributed such specimens of local origin, as they possessed. Special thanks are due to Dr. E. S. Simpson, of Western Australia, who made available several highly interesting specimens, together with his...

Jan 1, 1938

By C Boyle

Brockman 2 mine is located in the Pilbara of Western Australia and is operated by Rio Tinto Iron Ore. Mineralisation is hosted by synclines where there is structural complexity to focus fluid flow. Mineralisation is hosted by the Brockman Iron Formation. Mining is on 10 m benches and blastholes spaced at 6 - 8 m apart are geologically logged, sampled by shovel cuts, and assayed using X-ray fluorescence for ten chemical variables. Blast blocks are digitised by mine geologists to assign destinations of material within blasts. Resource evaluation drilling is on a spacing of 50 m × 50 m across known mineralisation and consists of recent reverse circulation drilling and older open hole percussion drilling. Sampling of resource evaluation drilling is by rotary splitters or riffle splitters, and assaying is by X-ray fluorescence for ten chemical variables. Ordinary kriging of resource evaluation produces a long-term resource model. This study examines whether mine planning would be improved by using a blasthole estimate to extrapolate grades into deeper benches and merging the blasthole estimate with the long-term model made using resource evaluation drilling. The two estimates are merged into one model using an inverse weighting based on kriging variance. However, reconciliation results in a test bench show the original estimate made using resource evaluation drilling more closely matches mine geology block outs than does the merged model. This is due to a local trend of more high grade and higher iron grades of high grade in the area. The blasthole estimate of deeper benches must use extrapolation and it is diffi cult to take local trends into account. In contrast, the estimation using resource evaluation drilling is mainly interpolation and is better able to handle local trends.

Jul 11, 2011

This paper deals with innovative techniques that have enabled personal computers to be used on the mine site to define, develop and manage an ore body resource, while being aware of the consequences to the environment. The same set of personal computer tools that are used for resource estimation, once the province of expensive workstations, can also be used by geologists, mining engineers, surveyors and environmentalists, in managing the whole mining process, including production, grade control, monthly reconciliation and stockpile management through to tailings the management, mine rehabilitation and the due diligence process of mine closure.

Jan 1, 1996

By Nichol R

- PART A The Hoppers Crossing Pumping Station is one of the principal components of the Western Trunk Sewer Project which replaces the 90 year old Main Outfall Sewer and will convey 60% of Melbourne's sewage flow from Brooklyn to the Board's Farm at

Jan 1, 1987