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By Grimstone LR, Leach JHJ

An analytical technique is described to identify areas of structural disturbance to coal and interseam strata in coal measures. It is based on exploration borehole data which records seam intersections and interseam lithologies. Computerised data bases have been developed to allow processing of large quantities of borehole records. The case study discussed is located in a tectonic setting dominated by thrust faulting. It provides a mechanism for the identification of low angle and bedding plane faults. In addition it allows the preparation of plans showing the areal distribution of the thrust sheets in the statigraphic section throughout the mine prospect. The technique requires the identification of normal undisturbed depositional thickness of coal seams and interseams to be determined. This is done for coal by the identification of coal ply distribution over the area. For interseam lithologies it is based on sedimentological modelling of lithology distributions, related back to the original depositional environments. Variations from the expected values are interpreted as structural Deformations.

Jan 1, 1986

Broken Hill South Limited's discovery of phosphate deposits in the northwest of Queensland in 1966 prompted intensive exploration which has proved phosphate rock in excess of 2,000 million tons at ten separate deposits. Systematic exploration for phosphate in Australia was initiated by the Company in 1964. Early in 1966, an investigation of oil wells in the Georgina Basin in the Northern Territory and Queensland revealed widespread anomalous phosphate in early Middle Cambrian Beetle Creek Formation and Thorntonia Lime- stone. Phosphorites recognised in oil wells in the southeastern part of the Basin, Queensland, led to the discovery of the Duchess deposits, Exploration of the Beetle Creek Formation since 1966 has disclosed nine other sizeable deposits north of Duchess around the eastern margin of the Basin. The Lady Annie and the adjoining Lady Jane deposits, by reason of their location, 160 miles south of the Gulf of Carpentaria, are expected to be the first to be brought into production. Beneficiation testing and engineering investigations commenced in 1967. Transport between the deposits and various port sites in the Gulf of Carpentaria has been extensively studied and a slurry pipeline as a means of transport to a deep water island port, is now being investigated.

Jan 1, 1971

The Sto Tomas II orebody of Philex Mining Corporation is a porphyry copper deposit located at Padcal, Tuba, Benguet, Philippines. It was mined through open pit method for the first two years starting 1958 and subsequently through underground method using the Block Cave System. The slusher type of draw was employed at the upper levels of the orebody from mid-year of 1959 up to 1994 and then shifted to LHD as the ore became more competent at the lower levels. Application of rock mechanics played a vital role during the conceptualisation of the LHD method of draw, the first of its kind in the Philippines. Rock mechanics is a combined responsibility of the geology and the mine engineering staffs, with the geology providing the vital information to the mine engineering to include in the mine planning the following:the general geology of the orebody; the ground characterisation through rockmass classification; determination of the cavability of the ore column (this includes our experience on airblasts which occurred during the early stage of our last slusher blocks); undercutting sequence; fragmentation of the rockmass in the ore column; drawzone spacing; proper draw control procedure; lay-out of openings; and the design of ground supports based on the rockmass condition. For the proper interpretation of the rockmass that would cater to the diverse mining situations, Philex adopted the modified geomechanics rockmass classification (Mining Rockmass Rating, MRMR) as this system is recognised and used by most of the block cave mine worldwide. This paper aims to discuss and present the role of rock mechanics in the analysis and determination of geomechanical issues encountered in Philex mechanised block cave operation.

Jan 1, 2000

By C R. Sundberg

Despite nearly a half-century of continuous production, the low-grade iron ore (taconite) deposits of North America remain economically competitive sources of raw materials for the domestic steel industry. The continued viability of these mature integrated mining-concentrationagglomeration complexes requires highly efficient utilisation of assets, especially the mineral resource. At Cleveland-CliffsÆ five North American managed operations, enhanced ore characterisation techniques are playing a critical role in their continued success. Due to the low-grade nature and complex mineralogical composition of these deposits, ore characterisation cannot solely rely on assay grades. Historically, taconite ore characterisation has augmented assay grades with bench-scale concentration tests to quantify recoverable mineral. The economic necessity for improvements in mill efficiencies and final product quality has mandated significantly greater knowledge of ore-related impacts. Cliffs Technology Center has met this challenge by developing a variety of novel iron ore characterisation techniques. The applications developed include both in situ and laboratory procedures, plus unconventional data integration methods uniquely suited for these deposits. This paper details the evolution of these novel ore characterisation techniques and their application to each phase of the operation: mining-concentrating-and pelletising. The improved ore characterisation techniques have contributed to successes at individual Cleveland-Cliffs managed operations including mineral recoveries exceeding 95 per cent and productivity increases exceeding ten per cent while consistently achieving customer product quality objectives.

Jan 1, 2002

By Zamel G. I, Zenari L. P

Technological developments in modem Tunnel Boring Machines (TBMs) and associated back-up equipment are offering significant alternatives for mining operators to consider, in the selection of equipment for coal mine development drifts, roadways, longwall gate roads as well as metalliferous mining declines and development drives.Greater flexibility in handling variable ground conditions, muck disposal and radius of turn as well as advance rates, are just some of the areas where modem TBMs can accomplish the flexibility that mine operators require to achieve cost-effective developments.Compact TBMs are achieving this acceptance because of the fundamental design of a shielded machine containing electrics and hydraulics within the forward shell, ability to achieve tight radius of curvature and grades, and ability to provide highly flexible support systems to meet all possible ground conditions.However, a single TBM design will not suit all mine developments, as each development method - while having common goals with all mine developments - will also require certain unique criteria to be fulfilled.

Jan 1, 1993

By R Huntley, D Sims

Pajingo gold mine produces over 240 000 oz Au per year from underground mining using longitudinal bench stoping methods with a 15 m sublevel interval. Average mine head grade is around 12 g/t Au, contained within quartz veins between 0.5 to 16 m wide. The veins dip steeply (>60¦) and exhibit strike variations which lead to many curved and meandering drive/stope geometries. Unplanned dilution at Pajingo is predominantly controlled by fault planes that subparallel the vein and commonly lead to slabbing failure from the stope walls. Initial efforts at determining maximum spans were based on using the Stability Graph method of stope stability. However the method had a number of shortcomings that did not address mine site observations, including previous mining, interaction of different joint sets and the presence of discrete shears which resulted in poor prediction of stability. A method was developed to rate the risk of dilution for a stope based on observations made in the ore drives. The method utilises profile mapping of the ore drive, structural features observed and the orebody itself, on 10 m spaced sections along the ore drive. A matrix of factors determines the dilution risk for stoping at the time of mapping and the rating is transferred to longsection plots in the office. The dilution risk rating is used to determine the position and density of cable bolt support aimed at lessening the risk, and can be used to review blasthole designs prior to finalisation. The method has been used for more than two years and has proven to be a good indicator of potential unplanned dilution (ie waste outside of ring design). A recent review of the dilution risk mapping process has indicated it is assisting in reducing the impact of dilution at the operation and has the scope to be utilised further in the design process.

Jan 1, 2002

Sasol Roche Blasting Services (SRBS) has undertaken a process of trialing and evaluating the use of the SMI electronic initiating system with the specific purpose of being able to fully quantify the benefits of the system over a pyrotechnic system. After an initial trial of three shots in mid-2001, it was decided that to fully quantify the system, a complete strip would need to be fired using the system so that any losses due to ramps or end walls would be the same for both scenarios. The results have shown a significant improvement over the use of pyrotechnic initiators in several key areas including percentage cast. Through the use of survey results, the increase in cast and subsequent net improvement in blasting has been quantified. These trials have set out to compare each system in comparable situations to determine the real benefits, if any, of the electronic system over the pyrotechnic one. As the percentage cast is relatively easy to quantify using modern survey techniques, it was decided that this would be the principle method of comparison. However, while the assessment only included survey results, any improvement in fragmentation size and consistency would have flow on effects on reduced running and maintenance costs.

Jan 1, 2003

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 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

TUNGSTEN occupies an outstanding position amongst metals to-day, for by its use modern manufacturing methods have received a wonderful impetus. The important part played by tungsten in the recent war is not generally recognized. It was tungsten steel, in the shape of highspeed tools, that kept our soldiers supplied with munitions of war at more than one critical period. Tungsten added the necessary hardness and durability to various metals which were indispensable for carrying the war to a successful conclusion. In the words of...

Jan 1, 1921

By Durucan S

The southern Attiki peninsula is a very interesting area from an environmental point of view. The port and the city of Lavrio is situated at the east coast of the peninsula with about 10 000 inhabitants and there are also a few villages in the vicinity. The south-eastern part of the peninsula hosts the famous Lavrio mines which exploited the silver bearing orebodies of the area for more than 25 centuries. As a result, soils around the city of Lavrio are polluted with high heavy metal loads. The area is also of archaeological interest, as there are well preserved remnants of ancient mining and processing plants and archaeological sites. Soil samples collected from an area of approximately 120 km2 around Lavrio were analysed for their metal contents and the spatial distribution of the concentrations of ten selected elements were estimated from these data sets. The spatial data analysis and transformation capabilities of Geographic Information Systems, combined with extensive mining and geological data, helped the authors to identify the extent and causes of metal pollution around Lavrio.

Jan 1, 1995

By S Youds

The backfilling operation at Olympic Dam mine supports a 9.8 Mtpa underground Long Hole Open Stoping (LHOS) operation. It involves a combination of Cemented Aggregate Fill (CAF), surface rockfill and underground rockfill. The fill material is introduced from the surface via boreholes into the top of the stopes. Due to the deleterious effects of the dust and the thickness of the atmosphere in the stope it is not possible to view the filling process either at optical or infrared (IR) wavelengths. The need for a means to measure the filling process is driven by the placement of both rock and CAF fill in the stopes. The large volumes and high relative cost of CAF makes the minimisation of CAF fill a business priority. Incorrect filling can lead to the sterilisation of ore reserve. The use of millimeter wave radar to view through the haze to give real-time data on the relative positions of the different fill masses is being developed as an in-stope fill monitoring device. This paper reviews the salient points of the technology and its potential use in the backfilling operation at Olympic Dam. The broader potential of this technology for use in the mining industry by æseeingÆ through water and dust laden environments such as that found in stopes and ore passes is also discussed.

Jan 1, 2002

Whilst decisions to commit projects have traditionally been heavily influenced by hurdle rates for d.c.f. analysis, it is suggested that evaluation of competitors' costs may be a desirable additional tool.The MICAS system developed over the past four years is described. This computer system uses standard costs modified by District and Mine factors to allow estimation of individual mine costs. The data base contains more than 15,000 items of data and more than 6000 costs are calculated.Recent applications include use for competitive analysis, predictive analysis, statistical analysis, and comparative assessments with scopes ranging from a few mines to the whole Australian export industry. Some areas where care is necessary are outlined and potential further uses are discussed.

Jan 1, 1985

By G H. Luttrell

The use of secondary desliming cyclones ahead of froth flotation cells to reject ultrafine (-45 ¦m) particles has become a popular option in the United States for preparing fine coal feeds for froth flotation circuits. In light of this popularity, several experimental studies have been performed at industrial plant sites to develop a better understanding of the impacts of ultrafine desliming on froth cell performance and, ultimately, overall plant performance. These studies included an evaluation of various circuit configurations incorporating different flotation technologies (conventional machines and column cells) as well as different dewatering systems (disc filters, screen-bowl centrifuges, and thermal dryers). The data obtained from these studies indicate that deslime circuits offer several important benefits including lower product ash, reduced product moisture, better froth handling characteristics, and lower capital and operating costs. In addition, case studies conducted as part of this investigation have been used to develop generic guidelines for how deslime circuits may be successfully applied to improve the overall profitability of fine coal flotation circuits for both the metallurgical and steam coal markets.

Jan 1, 2005

By Steinbrucker G

Improvements in mining by the application of electronics necessitates analy-sis of the objectives and problems. A detailed analysis has shown that increased tunel-ling performance is one of the most important objectives. In mining, the environmental conditions for machines, their handling and servicing are very hard. Therefore a health monitoring system for tunnelling machines in hazardous areas has been developed. This system measures operational parameters, such as-flow, pressure, temperature, etc., de-rives forecasts of possible failures from these values, and assists maintenance person-nel. Important data are transmitted to a surface computer via telephone cables. Health monitoring is based on the cognition that slow deterioration of characteristic parame-ters, e.g. fluid loss, are symptoms of wear. Sudden changes of machine parameters indi-cate sudden destruction. Computer technology is very advanced, but transducer technolo-gy has not,been able to keep pace. Filling the yawning gap in the mining industry is a challenge to technology and requires special techniques. Machine monitoring and automa-tion in underground mining is still in its infancy. A lqt of development and research work is still necessary. The risks are great-The expected benefit due to increased min-ing performance (up to 5 %) justifies the risks in development.

Jan 1, 1985

By Remilton D, Raston GR

The low price of nickel which has prevailed since 1982 has dictated that unit production costs must be minimised. Early in the crisis, a decision was made within Western Mining Corporation to reduce unit costs by increased rates of production, not by a significant reduction in manpower. This paper details developments which have taken place at Kalgoorlie Nickel Smelter to enable the higher production rates to be achieved, or to increase energy efficiency. It is significant that most developments were achieved without the need for capital expenditure.

Jan 1, 1985

By K Kinnunen

A strong correlation between the reduction degradation index (RDI) of production sinter and the titanium content of the sinter mix was identified at the Ruukki sintering plant between 2000 and 2004. The titanium distribution in different mineral phases was studied using samples from pot sintering tests. Titanium additions were made using two different materials: rutile and crushed titanium-bearing haematite pellets. While both titanium additions clearly increased the RDI, titanium seemed to favour secondary haematite. The study focused on the effect of titanium in haematite, because haematite is reduced to magnetite in the RDI test. During the haematite-magnetite reduction, reduction degradation was observed. To increase accuracy, the phenomenon was investigated first by sintering and then reducing synthetic minerals under controlled laboratory conditions at the University of Oulu. The effect of titanium oxide in solid solution in magnetite on the magnetite to haematite transformation rate was studied first in order to simulate the final stage of the sintering process. In other experiments, haematite samples doped with 0.5, 2.0 and 5.0 wt per cent titanium oxide were studied using thermogravimetry under a controlled gas atmosphere (CO/CO2/H2/N2). Sintered samples were reduced using the same gas composition as in the RDI test. Polished sections for optical microscopy and SEM-EDS analysis were prepared from both reduced and oxidised samples and unreduced sintered samples. The titanium oxide content of haematite had a clear effect on reduction degradation of the samples. Furthermore, increasing titanium oxide content in solid solution in magnetite radically accelerated the oxidation rate. Similar observations regarding the effects of titanium have been reported earlier, but this was the first time the effect of very small additions of titanium were shown to deteriorate blast furnace burden quality and a reason suggested behind the process.

Jan 1, 2007

By D V. Boger

The use of chemical additives to initiate such processes as particulate separation through flotation or dewatering through flocculation, is common in the mining industry. The dosing of additives is none the less poorly controlled from a process control viewpoint and it is perhaps fortuitous that over-dosing or misuse of chemicals is rarely catastrophic to the production cycle. In many cases, such events would go undetected if it were not for economic considerations. Recently, the advent of orebodies with finer mineral disseminations and the push for greater efficiencies in both production and tailing disposal have resulted in the need for greater control of the dosing and utilisation of chemical additives. The need to grind at higher pulp densities and to finer sizes and to dewater to higher solid contents are but two examples that require a more stringent understanding of the true role of additives in controlling the rheology of suspensions and the influence of additives on the surface chemistry of particles. The inter-relationship between the surface chemistry of particles and the role of additives in controlling suspension rheology is now well understood for systems in which the average particle shape in the mixture is spherical or close to spherical. Luckily, this is the case for a large number of systems in the mining industry and the true role of typical additives in these systems will be explored. Difficulties arise for suspensions containing clays or other platey or needle shaped minerals and in many cases, quite small quantities of platey minerals dominate the rheology of suspensions. The role of additives in controlling the rheology of asymmetric particle systems is more complex but the effect of the additive in changing particle alignment in solution is the key to understanding suspension behaviour. The manipulation of the rheology of asymmetric particle systems will also be explored.

Jan 1, 1998

By Fee DJ

Some four hundred million tonnes of low rank sub-bituminous coal occurs in four separ rate lobes at Leigh Creek. These deposits are in a sparsely populated pastoral area remote from industrial centres. Early development was retarded because of high mining and haul- age costs and the availability of other fuels. The search for additional fuels after the second world war led to thorough investigations into the burning characte-,istics of the coal and the discovery of shallow coal suitable for open out mining. The development of the field included the establishment of water supply, improved rail facilities and a town.

Jan 1, 1975

By Vnenk L, Hargraves AJ

Metropolitan Colliery has some areas of roof where immedi- ate support is required in development. The disadvantages of percussive roof bolting at the face have led to recent produc- tion trials with rotary boring and rapid=setting resin anchored roof bolts developed at the Colliery. The three innovations involved are: (1) the wet drilling of small holes with an all- hydraulic, portable rotary boring machine; (2) the rapidity of loading a "point anchored" resin bolt; and (3) the consistently high anchorage strength available. All three innovations provide striking advantages over the previously available alternatives. The greatest disad- vantage - that of cost of resin - is not prohibitive, and there is promise of improvement in the future. There are possibilities of variations of the techniques for special support problems in particularly difficult roofs.

Jan 1, 1971