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X-ray analysis of polycrystalline powder samples has grown beyond its roots in the world of laboratory research and is now regarded as one of the most powerful industrial process-control tools in the field of building materials. This is the key to characterise the element and crystalline phase composition of the material. This is due largely to the development of industrial X-ray analytical systems such as PANalyticalÆs twin solution, which has transformed the advanced analytical techniques born in the laboratory into a robust, workmanlike and easy-to-use tool for todayÆs heavy industries. The increasing use of alternative fuels makes the Bogue method less reliable. Therefore, the real phase quantification by the Rietveld method is the only choice. Additional fine-tuning of the Rietveld method by using alternative methods guarantees the most accurate quantitative results. Moreover, the recent development of ultra high-speed X-ray detectors allows for æon the flyÆ quantitative X-ray diffraction analysis and a truly interactive process and quality control.

Jan 1, 2008

By Boland J

Prediction of rock cuttability by various excavation machines such as tunnel boring machines, road headers, rippers, picks, roller disc cutters, excavators, etc is of major concern to both civil and mining engineers and rock mechanics. In principle, the design of a rock cutting tool is based on achieving maximum excavation with minimum input energy, minimum applied force, minimum equipment weight and volume and, more importantly, minimum tool wear. When a rock material is indented by the force of a cutting tool and then unloaded several material zones form underneath and around the tool. As the tool moves into the rock the volume of its associated rock cavity (ie volume of displaced rock) expands and depending on the indenter's shape various phenomena may occur. Immediately beneath the tool a small zone in which the stress state is more or less hydrostatic, is formed which is underlain by an inelastic, or damaged, material zone. Both size and shape of this damaged zone control the magnitude of the indentation force and the chip formation mechanism during unloading. The rock is unable to store the whole strain energy induced by the tool and consequently the extra energy is expended either in forming new fracture surfaces and/or in plastic deformation in the damaged zone. Therefore, it is not surprising to see that both perfect-elastic and rigid-plastic constitutive models are not generally suitable for modelling indentation of rocks. In contrast elastoplastic constitutive models are more appropriate as they can include both elastic and plastic deformations (Kral et al, 1993). Elastic solutions for several half-space indentation problems can be found in most text books on elasticity and in particular in Timoshenko and Goodier (1951), Sneddon, (1951), Poulos and Davis (1974) and Johnson (1985a). If a failure criterion, eg the Mohr-Coulomb failure criterion, is applied to delimit elastic solutions for indentation problems, a lower bound limit of the applied indentation force (for a given indentation depth) can be estimated. It may be noted that elastic analyses, without any delimiting failure criteria, normally overestimate the indentation force. Plastic solutions for a few indentation problems may be found in Hill (1950), Johnson, (1985a) and Alehossein et al (1992). When analysing the behaviour of indented rocks the choice of an appropriate constitutive model describing effectively the behaviour of the rock at various stages and phases during indentation is a challenging issue. Several questions need to be answered before starting an effective analysis. The first question is of course: Which one of these is more appropriate for modelling zones underneath and around a cutter, elasticity or plasticity theory, continuum damage mechanics or fracture mechanics, and what is the bridging link between these various theories? Which mode is more dominant in fracturing rock, tensile or shear mode? What governs the mechanism of chip formation? What is the function, shape and the behaviour of the pulverised zone that forms just underneath a cutter? Is the hydrostatic stress state assumption reasonable for this zone? How does the rock change during the absorption and dissipation of the input energy and how does the indentation energy vary with rock type and depth of penetration? How can we model the damaged zone under the indenter? Furthermore does a plastic material form beneath the pulverised zone? When and how do radial and ring cracks form around and under an indenter?

Jan 1, 1995

South Africa has joined the league of other major Western World countries by officially adopting its own code for public reporting of Mineral Resources and Mineral Reserves. The recently published South African Code for Reporting of Mineral Resources and Mineral Reserves (SAMREC Code or Code) (SAIMM 2000) is presented here in its local and global context. The main aspects of the Code are listed and elaborated upon. The Code has been written with the participation of the major South African stakeholders in the field including Government institutions, the legal confraternity and the mining industry. Relevant foreign organisations, such as the Australasian Joint Ore Reserves Committee (JORC) and the United Nations contributed to its compilation, and supported it. The Code thus enjoys endorsement both locally and, to a large extent, overseas. The Code is modelled on, and is 90 per cent compliant with, the Australasian Code for Reporting of Mineral Resources and Ore Reserves (JORC Code) (AusIMM, 1999). The paper also elaborates on the duties and responsibilities of Competent Persons signing off resource and reserve reports and on the new listing requirements of the Johannesburg Securities Exchange (JSE), formerly the Johannesburg Stock Exchange, which has officially adopted the Code.

Jan 1, 2002

IN dealing with this subject the intention is not to write a detailed description of the various methods in vogue on the Kalgoorlie field, but rather to give a brief outline of three of the methods which are most universally in force, and from which, ultimately, a few comparisons may be drawn. The three methods which the writer proposes embodying in this article are known as "The Rill," "The Flatback," and "The Shrinkage." For comparative purposes each method will be applied to a block of ore 500 feet in length, and opened up by levels 200 feet apart."The Rin" System. It is necessary in this system, for facilitating mullocking, to make connections between levels by rising and winzing at about every 100 feet or 150 feet along the orebody. After the leading stope is beaten off for the full length ofthe drive, the level is timbered. Single stulls are put in up to a width of fourteen feet. If the span is too great for stulls, set timbers or saddleback stuUs are used. Stulls are lagged over with 4-in gimlet poles, and wooden chutes are built at intervals of 50-feet. Ore passes are cribbed up through the filling directly above each chute, and are constructed of 7-in. round timber or 9 in x 3 in square timber, the passes measuring 4 ft x 4 ft in the clear.Occasionally a double pass may be carried up, one side serving as a travelling way. Stoping is commenced off the winzes, and rills are gradually formed, one on either end of each winze. The rills are generally at an angle of 37° off the horizontal, this allowing for the boring...

Jan 1, 1909

The planning, design and construction of a service tunnel, under a major arterial road between two hospitals are described. The multiple uses of the tunnel combine to provide a favourable cost-benefit ratio for the tunnel as part of a rationalisation of services between hospitals. The driven tunnel provides economic, program and approval advantages over that of a cut and cover construction. The cross sectional shape of the tunnel was determined during feasibility studies by the degree of weathering of the Silurian mud- stones, the shallow cover and the proposed excavation equipment as well as the functional requirements. The site investigations covering geotechnical, building, noise and level surveys provided input to the design documentation and construction phases. Monitoring of settlement levels and primary support stresses during early construction stages confirmed the adequacy of the proposed tunnelling methods and support to be used adjacent to the major building foundations. The 140 metre long tunnel was success- fully completed in April 1980 at a cost of $650,000.

Jan 1, 1981

By M Flanagan, T Sua, B Wright, T Carroll, B Van Dijken

"BHP Billiton (BHPB) West Australian Iron Ore (WAIO) conducts an extensive geometallurgy (geomet) program for its iron ore deposits in the Pilbara. The geomet program provides accurate information to infrastructure engineers, resource geologists, mine planning engineers and the technical marketing team on the performance characteristics of iron ores. Performance metrics include production planning, such as lump/fine splits, processing capability such as the level of ultra-fine iron ore and ironmaking blast furnace properties including tumble index (TI) and reduction disintegration index (RDI). Prior to the introduction of the current geomet program in WAIO, basic geometallurgical information was provided at the deposit level, such as deposit lump percentage and head grade chemistry. As the business value of geometallurgy was realised during the growth period of WAIO, the geomet process was reviewed and formalised into five steps: geomet drill planning laboratory measurement data management algorithm development block estimation.The geomet laboratory process produces simulated iron ore products from drill core, which are then subjected to physical geometallurgy test work. With the large amount of geometallurgy data collected, extensive databases are utilised to collate and organise the data to improve its usability within the business. Algorithms are created from the data to predict important geomet variables and a block estimation method is used to estimate geometallurgical properties into resource models. The predicted geometallurgy data is regularly reviewed at the different steps against plant and shipping data to allow refinement of the geometallurgy algorithms. It is also recognised that geomet data can be used to optimise the operations in existing processing hubs for improved production rate. In addition, future geomet programs will focus on generating data from all available drill core programs, not just dedicated geomet drill holes, and will incorporate new types of data, such as hyper-spectral information, for improved geometallurgical estimation.CITATION:Wright, B, Carroll, T, Flanagan, M, Sua, T and Van Dijken, B, 2013. BHP Billiton West Australian iron ore geometallurgy - past, present and future, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013, pp 105-110 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 29, 2013

By Moxon N. T, Berndt J. R

BHP-Utah Coal Limited's Peak Downs Mine is located in Cen- tral Queensland, approximately 200 km south west of Mackay. The annual raw coal production of the mine is over 8 million tpa, requiring the removal of about 40 million cubic metres of prime overburden. This is achieved through the use of five large draglines. The large depths of overburden (up to 55 metres) encountered over half the strike length of the mine enables cast blasting to be carried out in conjunction with draglines employ- ing the chopping method of digging. The objective of cast blast- ing is to use explosive energy to move as much material directly into spoil as possible. The additional costs of drilling and blast- ing are offset by reducing dragline rehandle. Two factors which are of primary importance to the design of cast blasts are initiation control and material velocity. High speed motion picture photography is a powerful diagnostic tool to quantify these aspects of blasting (Winzer, Montenyohl and Ritter, 1979; Chiappetta et al., 1983; Anon., 1983). The objec- tives of such analysis are to: 1. Determine the burden velocity, 2. Determine the time to initial movement (that is, the inter- val between a face hole firing and the initial movement of the burden), 3. Check the accuracy of the initiation sequence. BHP Central Research Laboratories (CRL) and Peak Downs Mine monitored a cast blast in the mine's Winchester Pit on 18 August, 1988. The objectives of this exercise were to: 1. Quantify current cast blast performance, providing a base case for comparison with modified blast design. 2. Compare two orientations of angled holes within the blast. 3. Assess the effectiveness of cast blasting utilising an air-deck. 4. Check blast timing with respect to burden movement times.

Jan 1, 1989

The Australian Constitution specifies certain powers of the Commonwealth Government to be used in its capacity as the national government. Certain of these broad powers result in the Com- monwealth having a facility to play an important part in the development of the mining industry. The State Governments, however, by virtue of their wide powers to regulate matters within the boundaries of a particular State, are more directly involved in the day to day administration and standards of activities of mining operations. In this respect the Common- wealth has something of a dual role because of its "State-like" responsibilities for the mainland Terri- tories. The components of the role that the Common- wealth Government discharges in relation to the mining industry are qualified to varying extents at particular times by the political persuasion of the Government. In absolute terms the components are as follows. 1. Economic management. The Commonwealth's fiscal and monetary policies have an important effect on industry as well as on State finances. In particular, the taxation regime employed by the Commonwealth Government is of direct importance to economic decision-makers in the mining industry. 2. International matters. International trade and commodity matters are, more and more, becoming an everyday part of the conduct of a nation's foreign affairs. 3. Exports. The Commonwealth Government, via the constitutional powers over overseas trade, have exercised varying degrees of control over mineral exports to achieve particular objectives. 4. Foreign capital and investment. Australia in general, and the mining industry in particular, is and will continue to be a net importer of capital. There appears to be bipartisan political agreement in Australia that foreign investment policy must be enunciated to ensure that investors. are in no doubt that Australia welcomes beneficial investment and technology from overseas. 5. Environment and Aborigines. Governments, both Commonwealth and State, have in recent years become more involved in these areas in response to their interpretations of community aspirations. 6. Energy. Access to assured supplies of energy is now viewed, by Governments worldwide, as a desirable asset to ensure the well-being of a nation's people and industries.

Jan 1, 1978

By Armstrong RW, Middlin B

The development, design, construction and operation of the new Solvent Extraction/BCA process plant at Copper Refineries Pty. Ltd., Townsville is described.The process offers substantial savings in electrical power costs, improvements in plant hygiene, and a lowering of materials handling costs compared with conventional electrowinning technology.The solvent extraction process extracts arsenic from copper Tank House electrolyte using a tributyl phosphate (TBP) - kerosene solvent. The plant incorporates fourextraction stages, two scrub stages, and three stripping stages to produce an arsenic-bearing low-acid strip liquor. This strip liquor is mixed with copper sulphate, and neutralized with ammonia to form a copper (II) arsenic (V) crystalline product, bicupric arsenate (BCA). This product is then used in the manufacture of chromated copper arsenate timber preservatives (Royston 1982).

Jan 1, 1985

By Todd S, Lam K, Hewitt A

A series of field experiments investigated the perfonnance of fine mesh curtain screens which were used to suppress coal dust in a transport roadway of a New South Wales colliery. Four types of screens were tested under dry and wet conditions. The screen materials consisted of flyscreen and garden "shadecloth" with single and double membranes of both materials. Personal dust samplers coupled to dust cyclones and filtration cassettes were used to collect the respirable and total components of dusts respectively. The procedure used for locating the samplers upstream and downstream of the screen was based on the roadway air velocity profiles. The number and configuration of the water sprays impinging onto these screens had significant influence on the results. The study showed that wet double layered flyscreen is the most effective of the four configurations tested.

Jan 1, 1991

By C Muñoz, N Ortega, J Vergara, D Avilés

Mass blasts have been the subject of extensive studies because of their potential benefits in mining operations. However, it has not been possible to advance due to the paradigm that states that the blasts near the designed final wall or to critical structures have to be low tonnage. Another reason is the absence of specialised simulation programs to more precisely determine the influence of the energy released by blasting to the rock mass. There are some studies that demonstrate the possibility of massive blasting that maintain the design of the final slope (Farias and Santander, 2014). It should be noted that these studies develop the concept that the size of the blast should not increase the peak vibration in the rock mass.The study was carried out in partnership with Los Colorados Mining Company. Analysis, reconciliation and wall control for two types of blasts were performed:blasting production: approximately 850 000 t, with special wall control considerationsblasting of approximately 950 000 t over the entire width of the bench.Monitoring systems were used in the near field and far field using examination of holes in order to obtain information to assess the impact on the rock mass and then to compare these to conventional blasting combining production and contour blasting.The results show that for a large blasted volume, production and/or those generated from toe to crest on the bench did not produce more impact in the rock mass than the conventional blasting.The conclusions drawn from this study are:an improvement in the excavation rate of 7500 t/h that is higher than the maximum rates normally obtainedthe peak vibrations of the P wave generated by both blasts did not exceed the peak particle velocity criteria (Vergara and Muñoz, 2014)holes examination indicating no difference in their entire length, in pre- and post-blast reviewover US$2 000 000 savings generated in the year (estimated by the client) (Avilés, 2014).CITATION:Vergara, J, Muñoz, C, Ortega, N and Avilés, D, 2015. Benefits related to applications of a mass blast in open cut mining, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 625–632 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By Warner N. A

There is an inherent problem in producing simultaneously lead, zinc and copper as metals in a single polymetallic smelting furnace. It relates to the condensation of lead and zinc from the gas phase under vacuum conditions such that metals in bulk form, either solid or liquid, are obtained as products rather than a fume or dust containing both metallic and non-metallic components. To understand this phenomenon, it has been necessary to establish mathematical models with computer simulation to identify the process requirements for effecting the objective of maximum bulk metal production with minimum fog formation. The theoretical framework of simultaneous heat and mass transfer involved in condensation from gas mixtures containing a non-condensable gas has been extended to the high temperature and reduced pressure conditions. These apply to new technology for polymetallic smelting now being developed in a project currently funded jointly by the Commission of the European Communities and the Mineral Industry Research Organisation. Under the right conditions it is theoretically possible to condense out both lead and zinc with minimal fume formation, but in all practical cases it is anticipated that some circulating load for reversion back to the smelter will be needed.

Jan 1, 1989

The prevention of silicosis by metallic aluminium has been reported by Denny, Robson, and Irwin in two papers. The first was published in 1937; the second, in 1939. The results definitely established that silicosis was prevented in animals by the inhalation of small quantities of aluminium. The present communication records subsequent progress in this field of research.

Jan 1, 1944

By A F. Cooper

Otago Schist in the Mount Patriarch, High Burn and Cameron Creek areas of northwest Otago grades from textural grade IIA in the east to textural grade III in the west. The entire region is of the actinolite-pumpellyite metamorphic facies. Lithologies in the area are interbedded turbidite sequences comprising pelite and psammite together with pebble conglomerate, greenschist and metachert horizons. The mineral assemblage of the schist is typically quartz-albite-epidote-actinolite-pumpellyite-chlorite-stilpnomelane-calcite. A good foliation is well defined in the area and is predominantly parallel to bedding, except in hinges of mesoscopic isoclinal folds. The structure of the area appears to be defined by a large southwest plunging isoclinal fold defined by bedding with a steeply dipping axial planar foliation. Kink folding and dextral strike-slip faulting in the area postdates the ductile phase of deformation. Pods of rhodonite, rhodochrosite, spessartine garnet, coombsite, caryopilite, Mnstilpnomelane and Ni-Cu-Zn sulphides were found in concordant metachert layers in the Mount Patriarch area. Metachert was also found in float in the Cameron Creek area. Malachite occurrences relating to copper mineralisation were also noted in a green metachert horizon on the eastern flank of Mount Patriarch. The coombsite, in only the third observation worldwide, is the most Fe-rich variety reported.

Jan 1, 2003

The mercury, gold, silver, copper, lead and zinc values of soils over altered and mineralised rock were determined to establish the potential use of mercury as an indicator element in geochemical prospecting. The results are presented to show that mercury can be used successfully in prospecting for precious metal mineralization in the Thames-Waihi area.

Jan 1, 1979

Based on the idea to copy crystallisation and precipitation phenomena occurring in nature, a new technology was developed allowing the preparation of metastable, mineral forming solutions. If these solutions are brought into soil or rock formations, directed precipitation of slightly soluble minerals takes place. Immobilisation of dissolved heavy metals as well as overlaying of reactive mineral surfaces with insoluble minerals can be achieved. It is possible to prepare solutions leading to the formation of gypsum, BaSO4, CaCO3, Ca(OH)2, Al(OH)3 or Fe(OH)3. The successful large-scale application of BaSO4 forming solutions was demonstrated in the former uranium mine Koenigstein of Wismut GmbH, (Germany).

Jan 1, 2003

Grade control is an important factor in the on-going success of a mining operation. Grade control criteria will vary depending on the commodity being mined. Financial considerations determine the actual grade control criteria at any one mine site. Mining and metallurgical capital and operating costs are ultimately used in ascertaining cut-off grades employed in grade control. The metallurgical characteristics of the ore, and ultimately the equipment selection and design of the plant, are based on samples provided by the exploration geologist. Ore variability is an important factor in designing the process plant. Ore variations, outside of those catered for in the design, as well as large ore changes on a daily basis, will impact on the metallurgical performance, and hence the economics of a mining operation. Therefore good liaison between the grade control geologist and metallurgist will undoubtedly lead to a more consistent, and more profitable mining operation.

Jan 1, 1993

By M Roper, M Lovitt

WMC Resources Olympic Dam Operation located in South Australia, is a poly metallic underground sublevel open stoping (SLOS) mining operation with a current annual production rate in excess of 9.0 Mt. Stope size, geometries, geotechnical considerations, drilling and blasting are critical components in stope performance. These factors are further influenced by stringent ventilation requirements due to the presence of airborne radioactive contaminants from uranium mineralisation. Stope planning is complex and mass blasting methodologies have been trialled at Olympic Dam with the view to reducing the frequency of stope blasts, improving stope stability, productivity and ultimately improving overall stope performance. A key aspect in the ability to undertake underground mass blasts of this scale is the application of i-konTM electronic initiation technology by Orica. In the past two years in excess of three million tonnes has been initiated utilising this electronic technology, with an average blast of 250 000 t ranging to the largest to date being 580 000 t. By providing flexibility in blast designs, the use of electronic detonators has allowed mass firings over multiple sublevels. This has resulted in a significant reduction in stope extraction steps compared to conventional pyrotechnic firings. The benefits of this reduction in the number of stope blasts are wide ranging from improved stability of interim stope voids between blasts, reduced blasthole damage, improved blast vibration management and reduction of complex changes to ventilation systems for blasting.

Jan 1, 2004

By M Xu and, P F. Wells, A N. Kerr, Y Shields

Triethylene tetramine (TETA) has been used in combination with sodium sulfite (sulfite) for pyrrhotite depression at Clarabelle Mill since 1998. This combination has been highly successful at reducing pyrrhotite levels in the bulk (Ni/Cu) concentrate. Although highly effective, the roles of TETA and sulfite are not well understood. Treating bulk samples of the circuit feeds through the miniplant enabled the effects of circuit configuration on the performance of the pyrrhotite rejection circuits at Clarabelle to be determined. Reasons for the different performance of the non-magnetic pyrrhotite rejection circuit in the miniplant were investigated and tested in the laboratory. The effect of different grinding environments in the laboratory was examined to better understand the depressing mechanisms of TETA/sulfite. Modification of the grinding chemistry improved the selectivity of pentlandite over pyrrhotite in the presence of TETA/sulfite at current plant dosages.

Jan 1, 2005

By Gordon DM

Tyres account for 25-30 per cent of the operating costs of large capacity haul units as used in open-cut mines.Tyre operating costs can be substantially reduced and often contained in real terms by applying knowledge that is now available.This paper describes certain specific advances in tyre management, namely batching, bias adjustment, cumulative plotting and the so-called "pressure-temperature" system of tyre pressure control, originated on the Mt Newman Mining Company's Newman minesite, and discusses the contribution that each has made to improving tyre management and reducing costs.

Jan 1, 1983