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By M Biesinger, R St C Smart

Diagnosis of the surface chemical factors playing a part in flotation separation of a value sulfide phase requires measurement of the hydrophobic and hydrophilic species that are statistically different between the concentrate and tail streams. Statistical methods, based on the monolayer-sensitive time of flight secondary ion mass spectrometry (ToF-SIMS) technique, have been developed towards this ultimate aim by measuring hydrophobic species (collector ions, dimers and metal complexes, polysulfides) as well as hydrophobic metal ions, precipitates and added depressant species. Reliable identification of specific mineral particles is central to this statistical analysis. A chalcopyrite/pyrite/ sphalerite mineral mixture conditioned at pH 9 for 20 minutes to study transfer of Cu from chalcopyrite via solution to the other two mineral surfaces, since this mechanism can be responsible for their inadvertent flotation in copper recovery, showed no statistical difference in the copper intensities on pyrite and sphalerite (selected from Fe and Zn images) after this conditioning. Principal component analysis (PCA) identifies combinations of factors strongly correlated (positively or negatively) in images or spectra from sets of data. In images, PCA selects these correlations from the mass spectra recorded at each of 256 ¦ 256 pixels in a selected area of particles. In the image mode, PCA has proved to be a much better method of selecting particles by mineral phase with clearer definition of particle boundaries due to multi-variable recognition. It has clearly separated a statistical difference in copper intensities between the sphalerite and pyrite phases. The PCA method has been applied to concentrate and tails samples collected from the Inco Matte Concentrator demonstrating extensive CuOH and NiOH transfer between the chalcocite (Cc) and heazlewoodite (Hz) minerals. Statistical differences illustrate the important discriminating depressant action of NiOH in flotation despite the activation of Hz by Cu transfer. The adsorption of the collector at specifically-identified Cu sites has been elucidated by the study. Importantly, the statistical analysis has been able to confirm some mechanisms and deny others proposed to control recovery and selectivity giving more focus on the control factors.

Jan 1, 2005

By B McIntosh

Sustainability in its simplest assessment has been defined as æmeeting the needs of the present without jeopardising the needs of future generationsÆ. For the mining industry alone, this statement could indeed be interpreted by the many cynics in our community as an oxymoron; as miningÆs very existence requires the extraction and consumption of finite resources. However for the future of industry as a whole, the integration of mining, minerals processing and manufacturing presents us with a unique opportunity to achieve sustainability through the continued supply of metals and materials for society, in a manner which can achieve positive social outcomes through a triple bottom line approach.The Kwinana Industrial Area has been Western AustraliaÆs premier heavy industrial precinct for more than 40 years and its prevailing level of prosperity will ensure it remains a significant contributor to the State economy through the 21st century.The Kwinana industries depend on each other for the production of essential raw materials vital to their manufacturing and refining process, an innovation that also has significant environmental benefits.Formed in 1991, the Kwinana Industries Council strives to foster positive interaction between member companies and with the local community.The aims are:to co-ordinate the activities of Kwinana industries on a range of common issues; provide effective liaison with the local community; promote a positive image of Kwinana industries; highlight contributions to the community by Kwinana industries; and work towards the long-term viability of the Kwinana Industrial Area. The Kwinana Industries Council facilities these aims by focusing on developing and employing leading edge technology, giving workplace health, safety and environment top priority, and taking a committed, responsible and pro-active approach to environmental protection, whilst forging a two-way partnership with the local community.The sustainability of industry is the key objective for the Kwinana Industries Council and through the involvement of the 13 member companies industry strives to:achieve efficient processing of resources to provide a range of goods and services needed by the community; achieve acceptable and decreasing level of environmental impact; provide jobs and income for our community; and engage co-operative projects that benefit the local communities, the State and Australia.

Jan 1, 2004

By Andrews B. S

The sinter plant at the Sulphide Corporation's Cockle Creek works produces a feed for the company's Imperial Smelting Furnace. The feed contains lead and zinc oxides and all the fluxes necessary for furnace operation. The quality of this feed is a major factor in furnace performance and the considerable flexibility of operation possible at the sinter plant has been used in efforts to achieve optimum operating conditions.Operating data is processed daily and information gathered from this source has led to three of the four improvements described.These improvements have resulted from elimination of gas recirculation, reduction of sinter returns sizing and alteration of ignition conditions and main layer fuel loading.

Jan 1, 1964

The aquifer at Phosphate Hill, north-west Queensland, presents special management challenges. The site contains a phosphate rock mine, fertilizer plant and camp. All of the site water is provided by the Duchess Embayment Aquifer, located within the Burke River Outlier of the Georgina Basin. The Duchess Embayment is a triangular shaped, Cambrian marine sedimentary basin consisting of siliceous and calcareous phosphorites, shales, siltstones and sandstones. It is fault-bounded on all sides and has a regional dip of 5¦E. The aquifer is largely confined to the siliceous facies of the Beetle Creek Formation. It has a very flat potentiometric surface and an average thickness of 45 m with confining beds above and below. The siliceous facies derives from weathering of the calcareous phase and is highly transmissive while the calcareous zone itself contains less water and is dependent upon interconnecting fractures for its permeability. Recharge appears to occur where the siliceous facies crops out around the edges of, and within, the Embayment. Aquifer management issues revolve around two points: successful dewatering of the orebody for mining; and efficient management to maintain water quality and ensure supply over the predicted 30-year life of the project. Current operations are extracting water at levels much below that originally estimated. This is having a detrimental effect on mine dewatering with the SWL lowering at a rate slower than anticipated. As a result, ore parcels are now beginning to intersect the water table, providing a major constraint to the mining plan. The aquifer drawdown cone is extensive and very flat so to keep the water table at an appropriate level for mining the management plan will include more aggressive dewatering to lower the level of the entire aquifer. The additional water will either be disposed of downstream or stored in a holding dam or via the use of artificial storage and recharge. Water resource management will also need to maintain the current quality. About 37 per cent of the water currently extracted forms the low chloride supply required by the ammonia plant and the power station. This ratio is expected to remain applicable under any future operating conditions but the low chloride resource is restricted so will require prudent management to enable the supply to continue. At current usage rates aquifer recharge versus use will need careful monitoring to ensure that the resource remains viable in the long-term.

Jan 1, 2003

By E Mofya, R Kaunda, P Lever

One of the fundamental requirements for being able to optimise blasting is the ability to predict fragmentation. An accurate blast fragmentation model allows a mine to adjust the fragmentation size for different downstream processes (mill processing versus leach, for instance), and to make real time adjustments in blasting parameters to account for changes in rock mass characteristics (hardness, fracture density, fracture orientation, etc). A number of blast fragmentation models have been developed in the past 40 years such as the Kuz-Ram model (Cunningham, 1983). Fragmentation models have a limited usefulness at the present time because:The input parameters are not the most useful for the engineer to determine and data for these parameters are not available throughout the rock mass. Even if the input parameters are known, the models still do not consistently predict the correct fragmentation. This is because the models capture some but not all of the important rock and blast phenomena. The models do not allow for ætuningÆ at a specific mine site. This paper describes studies that are being conducted to improve blast fragmentation models. The Split image processing software is used for these studies (Kemeny, 1994; Kemeny et al, 1999).

Jan 1, 2001

It is often assumed that geotechnical investigations or studies for open pit mines are confined to providing a slope design. However in an operating mine, the design is only one component of a mine geotechnical program. Reviews of slope designs are ongoing throughout the mine life. The concept of Pit Slope Management has been formulated because the design only entails one component of a total program that contributes to a safe, efficient mining operation. Risk is a normal part of mining. Effective management allows the risk to be contained or controlled. If the slopes are not effectively managed there will be increased risk for the operation. Experience has shown that utilisation of Pit Slope Management coupled with a broad base of experience to define the key controls on stability, provides a pro-active, objective approach. The reasoning is deductive and relies on the behaviour of the ærocksÆ. Once the key aspects are defined, studies are well focused, implemented as required and the risks can be effectively managed. When the key controls on stability are poorly understood reasoning is typically more ægut feelÆ. Under such circumstances studies, if carried out, may meet short-term objectives but often ignore the long-term objectives. Hence the risk to the project is greatly increased. This paper presents several case studies highlighting the above aspects and present elements of the Pit Slope Management Program approach which have been successfully utilised by the author to manage risk in mining projects.

Jan 1, 2003

The Coal Section of the Geological Survey of Queensland was formed in 1950 to plan and supervise systematic diamond drilling programmes to investigate the State's coal resources. For the first 15 years these programmes were con- fined to the established coalfields to prove reserves of coal suitable for steam raising for power generation. Adequate reserves were del- ineated during this period to provide coal for the operating lives of new power stations at Ipswich and Collinsville. Later exploration was aimed at a regional appraisal of coal mea- sure stratigraphy, particularly in the Bowen and Galilee Basins. This was followed, in some areas, by drilling to prove reserves to indic- ated status. Parameters were developed to allow a uniform approach to the estimation of reserves. Coal quality is evaluated in terms of potential utilization of coal. Reserves defined by exploration companies are assessed, and combined with reserves from Departmental drilling into a general table. Total reserves in situ amount to 9 962 million tonnes of coking coal and 7 333 million tonnes of non-coking coal. Approximately 20 per cent of coking and 40 per cent of non-coking coal were proved as a direct result of Geological Survey drilling programmes. Further explor- ation is planned for the Bowen and Galilee Bas- ins and may extend to the Surat Basin.

Jan 1, 1977

By S Jeon, K Aikawa, M Ito, A Kusano, I Park, N Hiroyoshi

In mineral processing of complex sulfide ores containing copper (Cu), lead (Pb), and zinc (Zn), flotation has been commonly used. Typical Pb mineral in the ores is galena (PbS), while some types of the ores contain anglesite (PbSO4). This article reviews our recent studies on the effects of coexisting PbSO4 on the flotation of complex sulfide ores, and a method to suppress the floatability of sphalerite (ZnS) in the presence of PbSO4 was proposed. Comparison of flotation experiments for different types of model samples showed that PbSO4 makes the separation of Zn from Cu difficult; that is, for the model sample containing PbS without PbSO4, Zn could be separated from Cu, while when the model sample containing PbSO4, Zn was recovered together with Cu as froth. Solution analysis and thermodynamic calculation suggested that Pb2+ was released from PbSO4 and reacted with ZnS to form PbS, acting as an adsorption site for the flotation collector, xanthate. This would be the main reason for high floatability of ZnS in the presence of PbSO4. As a method to suppress ZnS floatability for the ores containing PbSO4, a pre-treatment of the ores to remove PbSO4 prior to flotation was proposed. The results of model experiments using mixture of ZnS and PbSO4 showed that ~97 per cent of PbSO4 was dissolved within 30 minutes of pretreatment using ethylenediaminetetraacetic acid (EDTA) as extractant, and thus ZnS floatability was markedly suppressed. Moreover, Pb2+ extracted from PbSO4 during the pre-treatment could be recovered as zero-valent Pb by the cementation using zero-valent Fe as a reductant. The details of ZnS flotation in the presence of PbSO4 and the effects of the pre-treatment are discussed based on the results of surface analysis like XPS.

Aug 24, 2022

By MattelmSki M

Outokumpu Harjavalta Metals Oy has been producing nickel since 1962, based on conventional flash smelting technology followed by electrowinning of nickel. In the 1980s, a research project was initiated to develop a converterless direct smelting process to produce matte for further refining in the then existing refinery. The process was tested on a pilot plant scale at Outokumpu's research centre in Pori and was found to be viable. The process was named the Direct Outokumpu Nickel Smelting Process or the DON Process. At the turn of the 1990s, Outokumpu studied various options to develop its nickel business and the Harjavalta operations. As a result of this work, the DON Process was further developed to produce two mattes: low iron matte in the flash furnace to be leached in the existing leaching circuit and high iron matte in the electric furnace to be leached in the new leaching circuit. In Harjavalta's case, it was essential and important that the process could use the existing flash furnace and electric furnace without converters.

Jan 1, 1996

By Y Peng, D Liu, S Vink, B Wang

There have been strong industrial observations that clay minerals have a deleterious effect on mineral flotation grade and recovery. However, rigorous explanation on the role of clay minerals in flotation and effective ways to reduce their negative effects are not available. In this study, the flotation behaviour of low quality and high quality coal samples were examined at the Xstrata Oaky Creek Coal plant, and laboratory in fresh and recycled water with high ionic strength. Anionic and non-ionic dispersants including lignosulfonates and triblock copolymers were also tested with an objective of improving coal flotation in recycled water. It was found that overly stable froth was produced in the flotation of both low quality and high quality coal samples in saline water. Speciation modelling indicated precipitation of hydrophilic components which may adversely affect the flotation. Despite the overly stable froth, saline water produced much higher combustible recovery than fresh water without significantly losing the product quality. Lignosulfonate dispersants displayed a potential to improve the flotation in fresh water, but not in saline water. Significant flotation improvement was achieved with the triblock copolymer examined in both fresh and saline water.CITATION:Liu, D, Wang, B, Peng, Y and Vink, S, 2012. Determining the effect of clay minerals on coal flotation using saline water, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 151-158 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

The value derived by good mine planning is often underestimated as many mines steer their attention to the more immediate and more easily recognised successes made by the day-to-day operational æbush fireÆ fighting. Similar to machine maintenance, the efforts made to quickly rectify short-term breakdowns are well recognised; whereas the value derived from the work in planning, scheduling and undertaking preventative maintenance is not so obvious or readily quantified. Too often the focus of the business shifts to building and supporting an efficient operations team at the expense of developing a highly experienced team of mine planning practitioners that are well trained with procedures and purpose-built tools to develop optimum mining strategies. A resource has an inherent value based on its quality parameters and its likely mining conditions. How well that value can be unlocked is governed, to a large degree, by the proficiency of the mine planning practitioners, as they, essentially, set the foundation of the mine business and the path along which the mine will operate. The importance of having a well documented and procedural mine planning methodology that integrates both a thorough technical and economic understanding of the resource cannot be over emphasised. The aim of the mine planning process is to develop a robust mine design and production capability which can best cater for future uncertainty whilst providing the best opportunity to maximise cash flow into the business. The planning process must be transparent and auditable, clearly summarising the process steps and assumptions made to arrive at a justifiable and defendable outcome. To provide maximum value to the business, the planning process must be repeatable and scalable to enable easy replication throughout the different mines and projects within an organisation. The diminishing numbers of highly experienced personnel within our industry, coupled with the growing pressure to clearly demonstrate that appropriate due diligence has been exercised, means that well documented and monitored mine planning processes using purposed built and innovative tools need to be developed to ensure optimum outcomes.

Jan 1, 2009

By S K. Michelic, M Schickbichler, A Kharicha, E Karimi-Sibaki

The requirements for the controllability of metallurgical processes are increasingly becoming the focus of both industry and research. Advances in this field of research not only impact the stability of processes but often also influence the quality of the final product. One important way to examine processes in-depth, and thus show potential for improvement, is to describe them using physicsdriven models. In metallurgy, thermodynamic and kinetic descriptions of interactions between individual components of a system are often used to describe and analyse important metallurgical phenomena across the entire process. However, for the creation of physics-based models, boundary conditions and process variables must be implemented to enable a description that is as realistic as possible. The collection and generalisation of boundary conditions and process variables is, therefore, an important step towards functional models. The focus of this study is the determination of mass transfer coefficients between all components in a steel/slag/refractory system. For this purpose, experimental and theoretical methods are applied. Laboratory scale experiments are carried out in an induction furnace, and the mass transfer coefficients of the defined steel/slag/refractory system are calculated from changes in the chemical composition of the various components. Additionally, a calculation of the mass transfer coefficients based on dimensionless quantities is carried out. By comparing the values of the mass transfer coefficients determined theoretically and those determined experimentally in the trials, the suitability of the calculation is examined. The collection of mass transfer coefficients provides essential findings for future kinetic descriptions of inclusion modification based on the effective equilibrium reaction zone (EERZ) approach.

Aug 21, 2024

By K Biegaj

During the author’s 25+ year career in mine management in various parts of the world (mostly in Australia), the author has been privileged to live and work in mining towns (not FIFO) for more than 20 years. And has personally observed other people from the mining industry carrying out work at home in an unsafe manner, eg pushing lawn mowers whilst wearing thongs or performing electrical jobs whilst standing on aluminium ladders, as well as many others. It is common that injuries sustained at home whilst on break are not reported upon arrival back on a mine site. A large number of compensation claims for injuries at work, which in fact had been sustained at home, come at substantial extra costs to mining companies.

May 5, 2022

By G K. Robinson

Variations in many aspects of physical and chemical grade are often of concern to mining operations and mineral processing plants. In most circumstances these amounts of variation are predictable. At the time of planning new operations, we should be able to predict the amount of sampling and testing variation which our sampling devices, laboratory procedures and on-stream analysis devices will achieve. We should know how well our stockpiles, reclaimers and bins will homogenise material (or whether segregation will actually increase the amount of variation). We should be able to predict the amounts of variation that will occur on the important time or tonnage scales at the crucial p oints in our proposed operation. And once these amounts of variation are reliably known, mine planning will seem a little bit more like dealing with known knowns rather than like dealing with unknown unknowns.The first step towards quantifying amounts of variation for planned operations is to assess amounts of variation for existing operations. How many operations have estimates of amounts of variation in their databases? How often are people able to partition amounts of variation into amounts due to sampling error, amounts due to sample preparation, amounts due to assaying, and the amount of real variation in the stream of material?CITATION:Robinson, G K, 2012. Making sure that the amount of grade variation is a known known, in Proceedings Project Evaluation 2012 , pp 159-162 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 24, 2012

By B Washington, A Campbell, R Taylor

A sampling and measurement program was undertaken on the reaction shaft of the Olympic Dam copper flash smelting furnace. The object of the work was to provide information to validate a mathematical model of the burner and reaction shaft. Samples and measurements were undertaken through the burner inspection ports and the South East (SE) shaft sampling port about half way down the reaction shaft. Samples were collected to enable the calculation of particle loading of shaft gases, or sizing and chemical analysis of the partly-combusted feed, and the preparation of polished sections. Measurements were made of the temperature and sulfur dioxide content of the atmosphere, as well as plume velocity.To implement the program it was necessary to design and construct the following specialised items of equipment. For use at the burner inspection ports: a cup sampler for obtaining samples below the burners (temperature, solids loading and samples for characterisation).For use at the SE shaft sampling port and also at the settler level: trough sampler (plume definition and samples), isokinetic sampler (used as a velocity probe in this work), temperature probe (temperature traverses across the shaft), and sulfur dioxide probe (SO2 measurements across the shaft).The design of the sampling and measuring equipment is described, and examples are cited of the types of information obtained. The problems arising from working in a hot environment with molten or sticky particles are discussed.

Jan 1, 2005

Hard rock TBMs are very often open machine layouts, with just a part roof shield over the front of the machine. The whole system is designed for fast face advance and the economy of the project often depends entirely on the rate of advance. Typically, hard rock conditions will demonstrate stable and good ground for a major part of the tunnel. However, short sections of crushed shear zones with clay and gouge material may cause serious time delays. Spiling rock bolting has been proven to be very efficient under such circumstances, provided the fully grouted rebar bolts can be placed in a controlled and practical manner.Environmental restrictions are becoming more and more a part of tunnel excavation projects. Even hard rock TBM tunnelling may require a strict ground water control, because of consequences on the ground surface from lowering the ground water level. Such consequences may be surface settlement, negative influence on ground water resources or damage to vegetation.Pressure injection ahead of the advancing tunnel face (in this paper named pre-injection), using microfine cement and chemical grouts, is today a proven technology. As examples can be mentioned (Garshol, 1997) about 100 km of pre-injected tunnels below Oslo City and about the same length of subsea tunnelling elsewhere in Norway. Examples from other parts of the world are also available, like below Stockholm, Sweden, the Inland Feeder project and Hollywood Metro both in Southern California.To take advantage of spiling rockbolts and pre-injection, it is an obvious prerequisite to be able to drill the necessary boreholes in the right positions and at the correct angle. In drill and blast excavation this is simple, but in TBM projects it has repeatedly turned out to be difficult. More than once owners have accepted bids containing reassurance from the contractor that the drilling method will be sorted out later. Experience shows that if ælaterÆ means after start of the TBM operation, it is often too late.

Jan 1, 1999

By T Baumgartl, T Huynh, K Tungpalan, E Wightman, M Edraki, M Tayebi-Khorami, L Huang, S Palaniandy, E Manlapig

With the increasing rate of tailing production worldwide there is a growing concern about the hazards of tailings storage facilities (TSF). Past and current mining, processing and waste disposal strategies that focus on the extraction of the valuable minerals, and an economic assessment only, are no longer suitable. Social implications and environmental legacies must be included for effective evaluation. This is possible by using an integrated assessment framework to evaluate more alternatives, including the production of additional saleable and benign streams, alternative tailings treatment and disposal as well as options for reuse, recycling and preprocessing of existing tailings. Tailings are not viewed as a final waste product but as part of the resource. From the sustainability perspective the models developed in integrated research programs will contribute to more effective methods for assessing different scenarios and potential processes and lead to better environmental management, increased production of benign tailings and improved efficiency of water and energy use and thus more responsible resource stewardship of the ore resource.This paper presents preliminary results from a multiyear research program on integrated tailings management at the Sustainable Minerals Institute (SMI), The University of Queensland, called ‘Designer Tailings’. The project involves the gathering of experimental and observational information on tailings biogeochemical processes to design and modify the range of activities within mineral processing plants, upstream characterisation ore and gangue, and downstream tailings management for desired tailings properties and outcomes. This information will assist the development of new total integrated value chain CITATION:Edraki, M, Huynh, T, Baumgartl, T, Huang, L, Andrusiewicz, M, Tungpalan, K, Tayebi-Khorami, M, Wightman, E, Palaniandy, S, Manlapig, E, Evans, C, Farrokhpay, S, Bradshaw, D and Vink, S, 2014. Designer tailings – an integrated model for tailings management, in Proceedings Life-of-Mine 2014 , pp 599–608 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By A Lu, C Wang

The natural semiconducting mineral rutile and sphalerite exhibited highly photocatalytic activities on degradation of methyl orange under visible light irradiation. The isomorphous substitutions of host metal ions by foreign ions and other defect states in natural semiconductors altered the band structure, decreased the intrinsic band gap, and then made them very attractive for solar energy utilisation. Our study indicated that natural semiconductor minerals might be suggested as a new class of cost-effective and solar light-responsive photocatalyst.

Jan 1, 2008

By Giannini L. M

The determination of the "optimum pit limit" of a mine has long been considered as a fundamental problem of mine planning. A number of mathematical techniques have been proposed to solve this problem some of the more elaborate ones posing considerable computational difficulties for their implementation. Barnes and Johnson recently introduced "bounding techniques" to ease the computational effort required for determining the optimum pit. The aim of this paper is to point out and correct some errors in their techniques. A presentation of a general bounding algorithm is given.

Jan 1, 1985

Topography, location of coal bearing land and existing built-up areas severely restrict locations for overburden disposal and dumping sites north of the Latrobe River clear of the coalfields are assumed until internal dumping areas can be established.

Jan 1, 1982