Search Documents

By Mishra S. N, Mishra R, Sen P. K

Control of silicon in produced through the submerged-arc furnace can result in reduced power and coke consumption in addition to improving the quality of the hot metal. A thermo-chemical analysis of the production of ferro-chromium was carried out to devise strategies to control the recovery of silicon during the manufacture of ferro-chromium. The presence of three thermochemical zones in the furnace with respect to the reduction of silica was recognised from this analysis. Any strategy for the control of silicon recovery has to take cognizance of these thermochemical zones. The effect of various strategies on the silicon level in the hot metal have been evaluated. Possible strategies, such as the reduction of coke level in the charge; the replacement of quartz; pre-reduction of the ore and the control of the temperature profile are discussed in this paper.

Jan 1, 1999

By Belton G. R

The kinetics of the interfacial reaction of H2O on liquid silica-saturated iron silicates has been studied by means of measurement of the HDO-H2 isotope exchange reaction. The apparent first order rate constant, ka, was found to be inversely proportional to the H20/H2 ratio, consistent with two electron (melt to adsorbed/dissociating molecule) transfer mechanism and can be given by the expression In ka = -1.97 x 104/T + 1.57 - ln(pH2O/pH2), where the units for ka are mol cm -2 s-1 atm 1. The results of the current study are shown to be consistent with the indirect measurements of earlier work.

Jan 1, 1987

By M Mohammad Khani

An economic block cave is dependent to the characteristics of the rock mass at stages of caving. These are cave initiation, propagation and ore flow. In this research, the rock engineering system (RES), first established by Hudson (1992) to solve complex rock engineering problems, is introduced and verified against the well-established caving parameters established by Laubscher. There are two types of factors influencing caving and these are natural (cannot be controlled) and induced (operator controlled). A RES based interaction matrix is developed by determining the rating parameters required to reproduce the caving database using Laubscher’s caving parameters. This provides the relative importance of the parameters in the interaction matrix. After discussing the rock mass caving process and identifying all the effective parameters, an interaction matrix is introduced to study the cave initiation of rock masses. The expert-semi-quantitative (ESQ) coding method is utilised to assign the numerical value to each parameter’s interaction. Thereafter, the interaction intensity and dominance of each factor in the system is determined to classify these factors. Finally, all the parameters affecting caving operation and their weights on the RES system are identified. This new application of RES in block caving is very efficient and useful for any stage of caving studies and helps experts to make decisions more accurately.CITATION:Mohammad Khani, M, 2016. The application of rock engineering systems to block caving to identify the effective parameters, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 853–860 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By Kentwell D. J, Cusak C. J, Harvey-Kelly F. E L, M D. Goodz

The Morning Star Gold Mine presents an example of a prolific operation with considerable historical records, mine workings, drill hole logs and countless plans from greater than 20 adjacent mines which have now been consolidated to form the current project. Implementation of 3D computer modelling in the planning stages has provided an additional tool to integrate and refine geological models as a guide to some exploration strategies. It has allowed for a re- interpretation of the host rock units, dimensional constraints, new exploration extensions and provisional resource modelling. The initial consideration of this project was to integrate 135 years of mining history into a single database. Each historic mining area had an unrelated mine grid, often established parallel to the long axis of their main stopes; some were based on magnetic or true north. Survey plans were in chain, imperial or metric units. Through the manipulation and rotation of old grids, previously unrelated mine workings began to form continuous mineralised zones, with unmined portions still remaining in between the existing development. Furthermore the current drillhole database of >433 holes showed numerous confirmatory intersections of new mineralisation. A series of tiered tables were created within a relational database to derive guidelines for assessing data to attribute a Mineral Prospectivity Value [MPV] based on key indicators of mineralisation. Indicator logging now forms the basis of geological descriptions.

Jan 1, 1997

By V A. Chanturia, T N. Matveeva, V V. Getman, A Yu Karkeshkina

The development and application of new effective environmentally friendly reagents for the flotation of thin and ultrathin mineral components is an urgent task. The analysis of the nomenclature of chemicals, including flotation reagents and flocculants, showed that water-soluble polymers (WSP) might be used in flotation separation of fine grinding products containing non-ferrous and precious metals. Water-soluble polymers that are responsive to temperature changes are the most attractive as reagents during flotation. These are the thermo-responsive polymers or thermomorphic polymers. The presence of nitrogen and oxygen atoms in the polymer molecule contributes to the formation of a coordination bond with non-ferrous and precious metals. A research conducted at the ICEMR RAS within the framework of the scientific school of Academician of the Russian Academy of Sciences Chanturia helped to develop a method of flotation of finely ground mineral particles containing valuable components using modified thermomorphic polymers. The paper focuses on the experimental study of poly (vinyl caprolactam) (PVC) as a flotation reagent for gold recovery from finely ground mineral products. PVC is a ready-made water-soluble thermosensitive polymer that does not require complex synthesis. PVC has a high ability to form complexes in an aqueous environment when heated. According to experimental data, the polymer interacts with gold nanoparticles, contributing to the extraction of gold from fine mineral products and the tailings that makes it perspective as an additional flotation agent for the processing of gold-containing ores.

Aug 24, 2022

By P Aguilera, C Guerrero, M Tucker

With the advent of Electronic Detonator Systems in the global mining industry, as well as the development of high precision pyrotechnic delays, the measurement and analysis of delay performance (usually measured in terms of dispersion about a batch mean û precision, and the deviation of that mean from the nominal detonation time û accuracy), has become an important issue. Through the non-conventional use of existing Velocity of Detonation (VoD) measurement technology, it has been shown to be feasible to measure the precision and accuracy of delay detonator series connected in the same manner as a typical open pit bench hook up. This paper describes the work undertaken to compare and contrast performance results obtained using a range of instrumentation including High Speed Video (HSV) filming, digital counter timing using a Hewlett Packard Universal Counter and a digital VoD measurement device. The results obtained demonstrated the practical feasibility of using the latter technology in order to obtain relatively large amounts of data in a time-efficient manner, with a precision of better than 0.5 microseconds, if required. The results also confirmed the close statistical agreement obtained between the three forms of performance measurement, therefore permitting the substitution of the VoD measurement technique for the more capital cost intensive HSV technique and the slow, sample-by-sample HP Universal Counter method. This paper describes the methodology applied and the results obtained.

Jan 1, 2004

By R Strand, B Usher

Environmental compliance and mine designs are increasingly including assessment of flows and water qualities as a key driver to decision-making over life-of-mine. Integrated site-wide water quality models linked to dynamic water balances have been used for regulatory submissions, feasibility studies, operating mines and mine closure studies. These models, developed in GoldSim, link aqueous chemistry to the physical system of the site-wide water balance. Geochemical mechanisms included are determined from geochemical characterisation and site water monitoring, depending on the data availability at each site. External geochemical modelling using PHREEQC, version 2 (by D?L?Parkhurst and C?A?J?Appelo) and Geochemists Workbench (GWB), (by C?M?Bethke and The Board of Trustees of the University of Illinois) identifies the most important geochemical processes to be included in the model as a series of geochemical mechanisms which include source term loading rates, pH-buffering and equilibration of water quality. Water balance components include seasonal flow variability; waste facility water storage and system lags; run-off variability; milling processes and tailings production as a function of ore types; simulation of automated and scheduled maintenance of settling ponds; water re-routing for water treatment and freshwater demand, usage and storage.Case studies illustrating the use of these models for regulatory submissions and mine feasibility studies in a variety of climatic and regulatory environments show the utility and applicability of these models. Site-specific examples of these models developed by Klohn Crippen Berger Ltd are currently used at operating mines across the world. One of the larger mines where this is used is a mature poly-metallic mine in South America where the model has aided mine managers in understanding how various planned initiatives and potential water options will result in changes to flows and water quality. It is used regularly to inform water and waste management to minimise impacts to the receiving environment as a consideration of both flows and concentrations. The mine has also used the model in support of water treatment design, regulatory submissions and mine closure planning.Further examples of feasibility and operational/compliance assessment in arid and strongly seasonal environments for planning, regulatory and closure consideration of mine wastes and pits have shown the utility and usefulness of these approaches for a range of mining operations at various stages of mine life.CITATION:Strand, R and Usher, B, ?2014. Integrated site water balances and water quality models for decision-making over life-of-mine, in Proceedings Life-of-Mine 2014 , pp 271–284 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By Hempenstall J, English W

Mine management has a responsibility under the various acts of state parliaments for the adequate ventilation of existing workings. It also has a need to plan adequately for the ventilation of proposed workings. Future workings alternatives have become progressively more complex and ventilation planning of the various possibilities must be undertaken within an atmosphere of rapidly changing market circumstances, etc. Any non-optimal solution will prove more expensive than necessary on both capital and cost bases. Clearly these increasing and alternative ventilation demands of coal mines in Australia have multiplied the work load of ventilation engineers. Management in general has for some time been aware of the advantages of using computers for commercial applications such as payroll and stores inventory. However, while the hand held calculator has replaced the traditional log tables and slide rules for smaller engineering calculations, the larger digital computer has not made the same

Jan 1, 1983

The Mineral Resources Act 1989 was assented to on 25th October, 1989 after more than two years of consultation and negotiation between Government, the mining industry and other affected parties particularly the major rural organisations.The legislation proposes major conceptual changes in a number of areas and adopts a totally new approach to the definition of land and the mechanisms available to the mining industry for accessing such land.Unfortunately the passage of the legislation through Parliament coincided with the lead-up to the State election. Ultimately it became an election issue generating much adverse comment in the media particularly from rural and landholder groups. It was obvious that much of this anti-mining propaganda resulted from a lack of understanding of the legislation and the benefits that flow to the majority of landholders as well as the mining industry.It is essential that the contents of the Mineral Resources Act be thoroughly understood by all parties. Only then will all the State's resources be able to be developed in a multiple land use environment.This paper outlines the philosophy behind the new Act and the more important provisions contained therein.

Jan 1, 1990

By Medhurst TP, Trueman R, Hutchinson IN

A breaker line support (BLS) monitoring system, BLSmon, has been designed and constructed by the CSIRO and installed and commissioned at Laleham No.] Colliery, Queensland. This system was designed to record hydraulic leg pressure and canopy position measurements and relay these, in real time, to the surface. The system has shown itself to be capable of operating on the BLSs without any adverse affect on production. Analysis of the results of the monitoring exercise has shown that rate of change of leg pressures on the BLSs could be used as an aid in the prediction of adverse mining conditions. Under favourable mining conditions the supports were observed to initially unload from the set pressure, this unloading reduced with time and by the end of a typical lift cycle had either ceased or reversed slightly. This behaviour was considered to be due to one of four possible causes, these being; the compaction of floor debris, and/or compaction of the floor, and/or crushing of the roof and /or support creep. The actual cause can only be determined through detailed monitoring of both roof and support convergence. However observational data would suggest that compaction of debris and softened floor material beneath the supports was the most likely cause. The few positive loading rates recorded under these conditions were of short duration and occurred towards the end of individual lifts. Where mining conditions were unfavourable the negative rates of change of pressure, unloading of the support, were reduced throughout a lift, in both duration and magnitude, when compared with favourable mining conditions. Over the same period the positive rates of change were observed to be greater. The rate of change of loading and convergence can be utilised to identify the onset of instability in the lift area. However, before this facility can be utilised by the mine for the reliable prediction of instability more monitored data and sophisticated processing techniques are required.

Jan 1, 1992

By G MORRIS

The mining industry has been rightly proud of its environmental achievements and it would be fair to say that in some areas the Australian mining industry is at the forefront of world practice in environmental management and mine rehabilitation. The `environment' has certainly been a growth area over the past three decades with growing awareness in the 1960s, some large battles and the of significant legislation in the 1970s. The most important period however has been the 1980s and so far the 1990s where, in addition to the of some more rigorous legislation, we have seen the practical application of environmental management/rehabilitation Techniques.

Jan 1, 1992

By G Byrne, A Bowden

There is often a difference in opinion about the allocation of risk in the establishment of mine closure bonds or financial assurances. From the State’s perspective, protection is needed to ensure that the broader community is not left with the liability of properly closing a mine in the event of a default by the mine operator. Such a default might occur where an operator decides to abandon a site, perform incomplete rehabilitation, becomes insolvent or claims limited liability. On the other hand, mine operators who can demonstrate a strong financial position plus a record of social and environmental commitment and performance, argue that there should be some recognition of this in setting a bond that is less than the full cost of early closure. They argue that a mine rehabilitation bond based on the full cost of early closure is overly conservative and ignores the actual risk of the operator being in default. This paper examines an approach that incorporates the risk of default into the establishment of mine closure and rehabilitation bonds. CITATION:Bowden, A and Byrne, G, 2018. Mine closure bonds (financial assurances) – the ‘how much?’ conundrum, in Proceedings Life-of-Mine 2018, pp 32–34 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By D A. Kepert, I J. Tehnas, M A. Pudovsk

BHP Billiton (BHPB) was the first company to start iron ore mining in the Pilbara at Mt Goldsworthy in 1966 through Goldsworthy Mining Limited (GML - then Consolidated Goldfields Australia, Cyprus Mines and Utah). Operations later started at Newman on Mt Whaleback in 1969 with the Mt Newman Mining Joint Venture (MNM û then comprising American Metals Climax û AMAX, Colonial Sugar Refineries û CSR and BHP). In 1986 it acquired majority ownership of MNM, and at the same time the previously 100 per cent BHPB owned but undeveloped Yandi property came on board. Purchase of Jimblebar (formerly McCameyÆs Monster) occurred in 1990 and full ownership of Goldsworthy followed in 1991. With the exception of Jimblebar (100 per cent owned), all mines are now 85 per cent BHPB and the balance with Itochu and Mitsui. This evolution of the company resulted in an eclectic mix of mines/ores, each with their varied exploration and evaluation histories. Discussion of some aspects of these histories, and reflections on changes in exploration-related activities with particular reference to discussion of advances in geological understanding since the 1960s forms the basis of this paper. BHPB presently has open cut mines at four main centres û Newman, Jimblebar, Marillana Creek (Yandi) and Yarrie û and is currently developing the former GML Area C near Yandi. With the exception of NewmanÆs Mt Whaleback mine and immediate satellites, all are contract operated. Ore is carried on BHPB railroads (696 km total) for export through the companyÆs Nelson Point or Finucane Island shipping facilities at Port Hedland. Some is directed to the BHPB Boodarie Iron hot briquetted iron plant near Finucane Island. Over 73 Mt of ore was produced by BHPB in calendar 2001, and the company has now mined over 1500 Mt in Western Australia since their operations at Yampi Sound first started in 1956.

Jan 1, 2002

Australia has been an important producer of zinc minerals and metal for many years.Late in the last century Edgar A. Ashcroft, a versatile and enterprising electrical engineer proposed the treatment of zinc rich ores by roasting, followed by leaching to extract zinc, purification of the solution and electrolysis of the purified solution to produce zinc. Residues from the leaching operation were to be smelted in a lead blast furnace to recover lead, silver and gold.Ashcroft (1897-98) and (1898) has.given us a most interesting record of the attempts made at the Sulphide Corporation's plant at Cockle Creek near Newcastle, NSW, to put his ideas into practice. In spite of the best efforts of all concerned, including the use of electrolysis of aqueous chlorides and sulphates, zinc could not be deposited consistently and the project failed although lead smelting continued until 1922 (Woodward, 1965, p. 158). Based on later experience with Broken Hill materials the presence of undetected cobalt in the solutions was the likely cause of the inability to deposit zinc (Kirk and Othmer, 1956).

Jan 1, 1985

By J Pan, G Qiu

In this paper, an analysis is made of the present situation in the Chinese steel industry and its demand for iron ores. It is shown that the demand for iron ores has been growing substantially with the rapid development of the steel industry all over the world, especially in China. However, the iron ore market is currently in the situation where supply exceeds demand due to the economic crisis, with more investment in mines and less output of steel for several years ahead all over the world. Gigantic pressure is confronting the Chinese steel mills due to the too high and irrational price of iron ores. It is time to return the price of iron ores to a normal position much closer to their value. More attention has therefore been paid to developing low-grade and complex iron ore resources in China due to the irrational price of imported iron ores. More innovative mineral processing processes have been developed to tackle these complex resources. A systematic introduction to the development of beneficiation processes for low-grade iron ores is provided, including upgrading low-grade siderite, limonite, micron sized haematite and magnetite resources.

Jan 1, 2009

By T Weldon

In the last 15 years, it has become increasingly popular to win gold and silver from carbon strip solutions with electrolytic æsludgeÆ cells. The precious metal sludges produced in the cells are washed to the cell bottom and pumped into filters. Most new operations are specifying sludging cells, and many older operations are being retrofitted with up-to-date electrolytic sludge cells and filters. The new sludging cells are generally more energy efficient than older cells, but more importantly, the cell operations to remove product are much less labour intensive, cleaner, and the operator need not have physical contact with the electrolytically produced metal. A case study of a major North American gold producer (50 000 kg/yr) that removed old style stainless steel wool cathode cells and installed new sludging cells and sludge filters is presented. The effect of various impurities is discussed.

Jan 1, 2005

By S Hapugoda, A Edenton, L Lu

The blast furnace cohesive zone has a profound impact on hot metal productivity and quality, fuel consumption, operational stability and the lining life of the blast furnace. The high temperature properties of ferrous burden materials determine the configuration and location of the cohesive zone and have therefore attracted particular attention. While numerous standard testing methods are in use to assess the quality of ferrous burden materials for the blast furnace, these simple tests are generally conducted under fixed conditions, which often represent the extreme situations encountered by the burden materials in the blast furnace. Furthermore, none of these simple tests provides information on the high temperature properties of the burden materials, such as their softening and melting properties. CSIRO is equipped with a fully computerised testing facility to characterise the high temperature properties of ferrous burden materials under realistic conditions similar to those encountered in the blast furnace. This paper will first review the CSIRO softening and melting test method and then discuss the softening and melting properties of a variety of blast furnace burden materials, including sinter, pellets and lump ore, and their implications for blast furnace operation.

Nov 8, 2021

By N N. Viswanathan, D Kumar, S Kumar

In secondary steelmaking, calcium treatment is practised to modify the solid alumina or spinel inclusions into liquid or partially liquid calcium aluminates. It has been seen that the dissolved calcium reacts with sulfur or oxygen present in the steel to form CaS or CaO type of transient inclusions. Post-calcium treatment these transient inclusions further react with pre-existing alumina or spinel inclusions and modify them. In addition, direct modification of pre-existing inclusions is also reported in the literature. In the present study, laboratory-scale induction furnace-based experiments are carried out to melt electrolytic iron in an alumina crucible followed by deoxidation with aluminium. The CaS-based composite material, prepared in-house, is added after the aluminium deoxidation to study the stability of CaS at the steelmaking temperature. Multiple steel samples were also taken to track the dissociation of CaS by means of sulfur pick-up in steel. Additionally, inclusion analysis of these steel samples was also performed to track changes in the chemical composition of inclusions in response to CaS addition. It has been seen that the CaS dissociates leading to a gradual pick-up of sulfur in steel. The scanning electron microscope – energy dispersive X-ray spectroscopy (SEM-EDS) analysis reveals that the alumina crucible and floated alumina inclusions are modified into calcium aluminates and the extent of modification depends on the contact time of CaS with the two sources of alumina mentioned earlier. However, the modification of alumina inclusions in the bulk steel did not occur during these experiments.

Jun 19, 2024

By G Chen

Magnesite and dolomite are two salt-type minerals. The surface characteristics of these two minerals are almost the same. It is very difficult to remove dolomite from magnesite ores by flotation process. The present study was performed to develop a new collector and a better flotation scheme for magnesite from dolomite. The flotation tests show that there exists a significant difference in flotability between magnesite and dolomite when dodecyl phosphate synthesised with dodecanol, phosphorus oxychloride and other chemicals is used as collector. Sodium silicate was used as the modifier to improve flotation selectivity. It was found that sodium silicate selectively depressed magnesite at pH 4.5 - 7.5. The separation of magnesite from dolomite was achieved in a reverse flotation which resulted in a 76.1 per cent yield of magnesite with a grade of 47.3 per cent at 100 ppm dodecyl phosphate and 75 ppm sodium silicate. The flotation mechanism was investigated by characterising surface electrical properties and measuring the adsorption density of the reagents on magnesite and dolomite.

Jan 1, 2005

By H Jalalifar, N Aziz

In the ten years since the University of NSW proposed a pillar design methodology for bord and pillar operations, the Australian coal mining industry has changed substantially. What was primarily a bord and pillar design approach is now being applied to chain pillar design in longwall mines where the requirements are substantially different. The dimensions of chain pillars can impact on tailgate conditions (roof, rib and floor), seal performance, and surface subsidence. The status of chain pillar design practice in Australia is reviewed, with a focus on defining pillar strength, chain pillar loading, and assessing the performance of the roof/pillar/system. A new pillar strength equation is proposed for Australian coal that applies for all width/height ratios. An alternative analysis of probability of failure of chain pillars is presented.

Jan 1, 2005