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A wide range of models are available to computer process simulators that require a large number of parameters which often are physical measurements, coefficients, calibration factors and functional forms. This makes it intuitively difficult in the majority of cases, to tune the parameters in order to simulate a circuit in agreement with experimental results. Unit calibrators operating on the principle of least squares minimisation of the difference between predicted and observed plant data, are relatively successful when the parameters are unconstrained and independent of each other. In the case of constrained parameters, a set of carefully chosen transforms is presented which map the unconstrained variables being minimised into the constrained parameters required for the model. This technique has been used successfully with the Powell minimisation algorithm and it may also be applied to other unconstrained minimisation methods. Necessary model characteristics are discussed to enable these transforms to be applied to interdependent model parameters such as points of a graph. Examples of the calibration of several unit models using these transforms are presented. KEYWORDS: Calibration, optimisation, transforms, process simulation.

Jan 1, 1993

By McQuade CV, Riley SJ

Acid mine drainage is an unavoidable consequence of some coal mining operations. Typically runoff pH is below 3.5 and at these pH levels heavy metals are mobilised. Leachate from coal reject dumps may require collection and treatment to raise the pH and precipitate the metals before being discharged.A bi-product of coal mining operations at Clarence Colliery is coarse washery reject. At present the coarse reject is deposited above ground and rehabilitated. Adjacent to Clarence Colliery is the Kable's Transport Pty Ltd sand mining operation. It has been proposed that co-disposal of the rejects from both operations may produce a product whose leachate has near neutral pH.

Jan 1, 1998

Through the stress synthesis of many examples of macrostructure in the middle of China, it can be concluded that in the middle of Chinesetectonics there are two compression-torsion-forces, one of which ( from NW to SE ) came from the northwest side of Aerjinshan abyssal and giant fault("F1A", see Fig.7,8,9 ); the other (from S to N ) came from the south side of the north piedmontal fault of Kunlunshan-the south piedmontal fault of Qinlingshan ("F2K-F2Q", see Fig-7,829 ).Owing to the two compression torsion forces a new special type of structure named rotation-apart structure occurred from Chaidamu basin to Hebai, Henan, Anhui plain,from Caledonian movement, Hercynian movement,Yenshan movement to Himalayan movement, step by step In the north of Qilianshan during the late Caledonian movement: during the Hercynian movement it extended into a vast area including the Chaidamu basin and Eerduosi basin; during the Yenshan movement it spread over the whole area of Helanshan,Eerduosi basin and Hebai , Henan, Anhui plain. In the period of Himalayan movement all these structures revived .The rotation-apart structure controlled the distribution of all mineral deposits and also were the mineralizing structures.The relation between these rotation-apart structure and earthquakes is very close.

Jan 1, 1990

By D E. Langberg, D R. Swinbourne

The past century has seen the development and commercialisation of many new pyrometallurgical processes based on gas injection. The driving force behind this trend in smelting and refining technology was the increased productivity and resulting increase in capital utilisation achievable. However, measurement of system variables is not easy and their effect on the rate of the reactions involved is not well characterised. One of the critical parameters is the gas-liquid interfacial area produced by gas injection. Related variables such as bubble size and velocity, and gas hold-up fractions in aqueous systems have been measured using combinations of physical (visual, audio and electrical) and chemical techniques. Models have been developed relating interfacial area to physical properties and operating variables and attempts made to extrapolate these to high temperature, liquid metal systems. The only attempts at validation of these models have used either low temperature liquid metals, such as mercury or WoodÆs Metal, or operating plant data. This paper reviews existing knowledge of the effects of system variables on total interfacial area in gas injection systems. Interfacial area is calculated from a range of published experimental aqueous and liquid metal systems and used to assess existing models. An operating region diagram was developed to assess dynamic similarity between experimental and industrial systems. It highlights areas where further research into both measurement techniques and experimental system variables is required in order to extend knowledge and guide further technical and design advances into the 21st century.

Jan 1, 2000

This paper attempts to draw together the experience of over 30 years of research and practice in the United Kingdom on the rehabilitation of abandoned metalliferous mining wastes. The reliance on water when the mines were operating has implications for water quality and the techniques used to restore sites to alleviate the principal impacts of the mines. Drivers of reclamation included concerns about human health from wind blown dust and pollution of watercourses as well as perceptions of dereliction. Techniques of reclamation used involved removal of spoil from near to surface watercourses, capping of spoil, diversion of watercourses, use of impermeable membranes, prevention of surface sinks into underground workings and the use of constructed wetlands. The issues to be dealt with in mine reclamation have become more complex and sometimes diverge. The schemes in the 1990s described have been effective in dealing with pollution from spoil heaps and small but significant adit discharges; however, significant issues, particularly those of large flows of polluted water from mine sites, still need to be dealt with. Although the paper describes the legacy of mining, which largely finished in the late 19th/early 20th century, similar issues but on a larger scale are to be found in more recent mining, for example Eastern Europe. In many of these areas minerals still remain to be won and dealing with this legacy may fall on new mining developments.

Jan 1, 2006

By C Linklater, A Garvie, D Kentwell

Various Australian and international regulatory bodies (Environmental Protection Authority, 2015) require an early assessment of the geochemistry of waste rock. This usually includes estimates of the locations and volumes of potentially acid forming (PAF) materials and requires sampling of the waste rock zones as well as submitting the samples for a series of tests. We know that the required number of samples will vary depending on rock type, mean sulfur levels and spatial variability of sulfur as well as total volume. The key question is how do we know when we have enough samples?This extended abstract describes the application of geostatistical methods to examine how sample numbers and sample locations influence the preliminary conclusions that may be drawn for early stage waste characterisation.CITATION:Kentwell, D, Garvie, A and Linklater, C, 2016. Geostatistics and sample numbers from an acid and metalliferous drainage perspective, in Proceedings Life-of-Mine 2016 Conference , pp 12–15 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By Muto S, Okada S

At Tamano Smelter, part of the furnace settler is electrically heated by electrodes placed internally. This practice provides good control of the settler conditions. The authors have been investigating improvements in furnace operations, especially to decrease the copper content in the slag discarded from the settler. The important operational points on the control of magnetite in liquid matte and slag are discussed on the basis of the thermodynamic calculation method developed by Prof. S. Goto. The behaviour of magnetite in the practical furnace has been studied by using a torsion magnetometer and a solid electrolyte oxygen-sensing cell.

Jan 1, 1980

By White A. H, Vihena M. T M B

Presently, orebody modelling consists basically of fitting a mathematical model to represent spatially a certain geological variable, generally grade. An orebody model is constructed from a set of sample data obtained from various locations in the orebody, thus it is only one form of representation of the true phenomena. Checking the compatibility of the data with the modelling procedure is the most important factor when assessing confidence in the orebody model. The level of confidence in the model will depend on the adequacy of the data set and the validity of the basic assumption required by the modelling method. Fractal geometry is one way of modelling the spatial distribution of a geological variable in an orebody geometry. Fractals can be used to interpolate the Z(x) geological variable at unsampled sites. The concepts of self similarity and self affinity that form the basic assumption of fractal geometry theory which areinvestigated. The population distribution of the geological variable in question must be examined to determine the appropriateness of both fractal geometry and geostatistical modelling methods. The selection of the most appropriate method depends on the available data. A researcher or a practitioner needs to understand the strengths and limitations of the various modelling methods before choosing the most appropriate method. This study investigates the fractal properties of grade distribution using the variogram and some proposed variations as techniques to measure the fractalness. The aim is to assess applicability of fractal geometry theory to modelling ore grade distribution in a deposit. A comparison of the results demonstrates the methods which better capture the spatial behaviour of the variable under study.

Jan 1, 1995

In North-West Nelson the Riwaka Complex, a linear basic intrusive complex, is exposed for approximately 45 kilometres. Some 500 kilometres south, across the Alpine Fault, a linear zone of similar but less well known basic intrusives that may be correlatives of the Riwaka Complex is exposed discontinuously for about 80 kilometres. The Complex was emplaced at several centers along a major tensional fracture zone that developed in upper Carboniferous to Lower Permian time. This fracture zone probably formed in response to the development of a west dipping subduction zone that gave rise to the Permian volcanic arcs in east Nelson and western Southland. The Riwaka Complex contains three rock suites. The Fractionation Suite, characterized by cyclic mineral layering and small scale cumulus banding is the largest and is divided into the Ultramafic, Hornblende and Plagioclase Series, each of which is subdivided into several units. The Cumulus Gabbros represent a restricted but important suite of unusual composition, while the third suite is the late phase Diorite Suite.

Jan 1, 1980

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

Study on the Recovery of Zinc Minerals from the Tailing of a Lead and Zinc Mineral Processing Plant

Sep 13, 2010

In order to understand the technique, basic theoretical principles of radiation emission and in- strumentation theory are reviewed. Methods of surveying, reduction of data and interpretation are outlined. Other applications of the technique (e.g. in airborne geological mapping), as well as its specific use in uranium exploration, are discussed. By means of case history-type examples the successful applicant of gamma-ray spectrometry, as a tool in Australian mineral search, is demonstrated.

Jan 1, 1969

The optimisation of capital in the total planning context has broadly two components: ò maximising the efficient utilisation of capital against competing capital demands; and ò maximising the efficiency with which the industry's capital requirements are sourced. This paper focuses on the latter of these two concepts, as I wish to highlight that within the coal industry the inefficient sourcing of capital has resulted in the inefficient utilisation of capital. In discussing the optimisation of capital within the coal industry I would like to outline three fundamental issues which currently impact the industry and its application of capital: Initially, from the perspective of an independent investor, the perceived risk associated with investing in a volatile industry cycle has not permitted appropriate funding structures to be created thus leading to an inefficient utilisation of capital. Secondly, investors seeking out a windfall gain have established a practice of trading in the assets rather than encouraging recapitalisation. And lastly the mismatch of supply and demand leading to the establishment of new projects which include a percentage of offshore investment has fostered an environment of lower returns and subsequently a dilution of capital.

Jan 1, 1991

By Treglown N

In any mining operation the curtailment of rising operating costs is of prime concern to management.One area of activity where costs are often disguised is that of longhole secondary breakage.This paper outlines sane operational techniques that have been considered and tested, resulting in improved fragmentation fran longhole stope blasts at New Broken Hill Consolidated Limited mine, Broken Hill, NSW.

Jan 1, 1985

At Cliffs Natural Resources Ltd (CNR) crushing and shipping sample stations, precisions are estimated for the sampling, preparation and measurement stages of iron ore sampling in accordance with ISO 3085 (2002). In this Standard, gross duplicate samples are prepared at each of the three stages, yielding eight measurement assays. Appropriate calculations of the differences between assay pairs are then made to estimate precision of each stage of sampling. The International Standard for checking precision in iron ore sampling, ISO 3085 (2002) prescribes a method for identifying outliers that is ambiguous and possibly inappropriate. The procedure also makes an unnecessary implicit assumption, that the differences between assay pairs are normally distributed. The Anderson-Darling statistic is used to demonstrate that in some cases the assay pair differences have distributions significantly different from normal. When applied at CNR as specified, the Standard leads to precision estimates well below the expected values, thus overestimating the sampling method's capability and limiting the opportunity for real process improvement. This paper suggests an improved method of estimating sampling, preparation and measurement precision. A bootstrap procedure is used to estimate confidence limits for the calculated precision estimates. The proposed method would be suitable for testing blasthole precision. The discussion is supported by extensive simulation modelling of realistic data.

Mar 1, 2010

Mackenzie (1968, p. 167) inferred that amphibolitelayers grade into and may be correlated with footwall Potosi gneiss where it is thin under the thickest development of the "lead lode" in the New Broken Hill Consolidated mine, Broken Hill. This gradation from amphibolite to Potosi gneiss is tacitly assumed in many of the constructed crosssections of the southern end of the orebody, where amphibolite and Potosi gneiss, defined in hand specimen, are correlated in adjacent drill holes. The basis for such correlations is the observation that some amphibolites in drill core lighten in colour from black to grey along the core and grade into an unlayered rock containing conspicuous pink garnets, which resembles Potosi gneiss (for descriptions of Potosi gneiss see Andrews, 1922; Gustafson, BurreIl and Garretty, 1950; Carruthers and Pratten, 1961;\Ternon, 1969).Average chemical compositions of "footwall" Potosi gneiss and "upper" amphibolite (Hawkins...

Jan 1, 1972

The appearance of the Cornish miner in South Australia was, in the simplest terms, the result of resource development economics. In Cornwall in the middle of the 19th century tin and copper mining was declining, while in the new colony of South Australia copper mining was booming. Experienced hard rock miners in Cornwall there- fore escaped unemployment at home by accepting an assisted passage to South Australia. There, in a colony where they were needed, they made their skills available and received good wages. There are many testimonies which support this simple thesis. Take for example the following extracts from contemporary newspapers in Corn- wall: Persons of small capital will find this an excellent opportunity for emigrating to the young and thriving colony ... The miner will find a rich and unbroken field for his operations. The Colony abounds with minerals... (West Briton, 19 July 1844) Miners make a great deal of money here (South Australia). All of them earn ú2 to ú3 per week and in many cases when they have a portion of the mine on tribute one person has cleared ú100 in a couple of months or so. (Cornwall Royal Gazette, 21 July 1848)

Jan 1, 1987

By Y Cui, G Cao, H Zong, J Zheng, J Wang, S Yue, J Zhao, B Li

The iron (Fe) concentration in nickel slag is high, making its recovery and utilisation a hot and challenging topic. In the nickel smelting process, using CaO instead of SiO2 to adjust slag’s composition, and then directly reducing Fe from the output of molten slag is a more feasible method in practice for Fe recovery in nickel slag. The adjustment of slag’s composition in the nickel smelting process will have an impact on the distribution of impurity elements such as Pb, Zn, and As. In this paper, the slag adjustment of nickel smelting process was carried out with the oxygen-enriched topblowing system. The distribution of impurity elements in the smelting products with each composition slag was conducted by using thermodynamic software. Experimental verification was performed with rich oxygen top-blowing, and the distribution characteristics of impurity elements in the smelting products were characterised to explore the differences in mineral phases of impurity elements with each smelting conditions, elucidating the distribution patterns of Pb, Zn, and As in each phase. The results indicate that after slag adjustment, impurity elements are more easily to volatilisation and removal into the gas, reducing their total concentration in slag and matte. In the slag, the existence form of Pb, Zn is changed from silicate to ferrate, and As is changed from arsenate to low-valent arsenic oxide. It is easier to decompose the impurity-containing mineral phase and remove the impurity elements in the subsequent iron extraction process.

Jun 19, 2024

By S Q. Zhao, J H. Wei

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Xitieshan lead-zinc deposit is located in the north margin of the Qaidam Basin, Qinghai Province, China. It is one of the largest massive sulfide deposits in China and is supposed to be of the sedimentation-exhalation (SEDEX) type. Based on the main ore mineral and sulfur isotopic compositions in sulfides found in the wall rock, the S of the deposit is considered to originate from the mantle, but the fluid potentially mixed with sea water during the hydrothermal circulation exchange. The study of lead isotopes shows that the metallogenic material is characterised by the mixture of orogenic and upper crust sources. The lead isotopic signature of the wall rock is similar to that of the ore, which shows synsedimentary characteristics. According to the composition of the rubidium and strontium isotopic signature, the value of 87Sr/86Sr is lower than the average value of that in the crustal rock, which is larger than that of the mantle. Hence, the metallogenic materials of this deposit mainly originate from the crust, which is related to materials of volcanic rocks activation and migration of the deep hot circulating water. The process of the metallogenic fluid circulation shows continuous interaction with crustal material and lead to continuous enrichment of the ore forming fluids. From the study of the fluid inclusion microthermometry of the ore and the associated minerals combined with the C, H-O, Si isotopes, it is believed that the metallogenic fluid is mainly coming from the mantle or the deep magma chambers. The rising deep fluid then mixes with the sea water. The carbon dioxide escaping and mixing with sea water during the hydrothermal exhalation process leads to the rapid precipitation of the hydrothermal fluid to deposit metal. That is proposed as the principal formation mechanism of the Xitieshan deposit. Further studies are proposed, including obtaining geochronology data from this deposit.CITATION:Zhao, Z X, Wei, J H, Liang, S N and Zhao, S Q, 2015. Advances in research on metallogenic mechanisms for the Xitieshan sedimentation-exhalation lead-zinc deposit, Qinghai Province, China, in Proceedings PACRIM 2015 Congress, pp 487–494 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Tin mining has taken place in the New England region of New South Wales since 1872. Until fairly recent times there was little pro- vision made for environmental protection. Mining methods,which included ground sluicing and open cutting,had considerable environmental impact. Much of the topsoil was lost and there is little vegetation on the infertile and at times toxic, subsoil. Thus much of the lands disturbed by mining have not been stabilised and are eroding, causing extensive pollution of adjacent watercourses. There are more than 1500ha of abandoned tin mine sites in the New England, representing one of the worst rehabilitation problems in New South Wales and reflecting poorly on the mining industry as a whole. Recent tin mining operations incorporate progressive rehabilitation in their mining cycle. Topsoil is stockpiled and later respread. This topsoil contains a seed source, facilitating revegetation and thus stabilisation. The tin mining industry, under considerable cost pressures at present, is seeking a cost- effective revegetation technique. Most of the mines in the New England are situated in a forest environment. Trials have been conducted in the past using exotic pasture species with limited success due to the characteristics of the subsoil. Other revege- tation trials have used pine or eucalypt tree species. The cost of these techniques is a major disadvantage. Certain acacias species were observed colonising disturbed tin mining areas on very infertile subsoils. Acacias have a number of characteristics indicating a possible applic- ations in mine rehabilitation programmes.

Jan 1, 1987