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By Finch W, Dunne R

Understanding how liberated and unliberated minerals behave in comminution and classification circuits is of vital importance to ensure that maximum liberation occurs without unnecessary and costly overgrinding. This paper presents the results of a study carried out by the Julius Kruttschnitt Mineral Research Centre and Newcrest Mining of the liberation performance of Newcrest Mining's New Celebration grinding circuit. Using data from surveys of the circuit, together with QEM*SEM analyses of individual streams, a detailed picture of the liberation and classification of gold-associated pyrite is presented. In addition the relationship between the QEM*SEM analyses and results from laboratory leach tests are also discussed. Using the survey and QEM*SEM data, mathematical models were constructed of the performance of the ball mill and cyclones, and simulations carried out to investigate ways of improving the performance of the circuit. The results from the more promising scenarios are Reviewed.

Jan 1, 1993

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 B, T Norgate, S Sanetsis, R Davidson

Global cement production accounts for about five per cent of man-made CO2 emissions (WBCSD, 2002). Such operating practices will increasingly be considered unsustainable, unless significant reductions in environmental impact can be realised by the industry.Slag is a high volume waste product from ironmaking, with about 300 kg of slag being produced per ton of iron. Critically, one ton of slag waste, if used as a replacement feedstock for Ordinary Portland cement (OPC), can prevent around one ton of emitted CO2 since no calcining is required. Slag cement blends can also show superior properties compared to OPC, such as lower heats of hydration and higher late strengths, but more development is needed to overcome their low early strengths. Rapid quenching of molten slag is required to produce æhydraulically-activeÆ binder when reacting with OPC; but water quenching can also require between five to ten tons of water per ton of slag at the plant. æDryÆ granulation (atomisation) is emerging as an alternative technology, the resulting solid product does not require drying, and possibilities exist for recovering heat energy from the hot slag.CSIRO Minerals has well-developed skills and equipment in pilot-scale pyrometallurgical treatment, and granulation of molten slag, including traditional wet, and also dry methods. Techno-economic desktop studies can also be used to help quantify factors such as value-adding of treated waste products, potential reductions in CO2 emissions and carbon credits, reductions in water consumption, and the possible decreased energy costs associated with fine grinding of dry slag granulate.The authors will present preliminary results from slag atomisation/dry granulation testwork (0.5 - 2.5 kg scale) and associated modelling studies, conducted using a æsyntheticÆ and industrial ironmaking slag. Outcomes from a techno-economic study on production of cement utilising wet or dry atomised slag granulate will also be discussed in detail.

Jan 1, 2004

Completing its historical role the opera tion of copper blast furnace of the Saganoseki Smelter was terminated in 1970, but it left some interesting data on metal lumps formed at the furnace bottom. Analysis disclosed the lumps to be speiss containing 100 to 10,000 g/t of Au and Ag and stratified to iron speiss and copper speiss. Solidifying temperatures of iron speiss and copper speiss being approximately 1,090¦C and 800¦C respectively, copper speiss precipitated at the lower side. The distribution coefficient of Au and Ag between matte and speiss (g/t Au(Ag) in matte / g/t Au(Ag) in speiss) is in the range of 1 x 10 2 to 2 x 10 ' and 1 x 10 1 to 5 respectively. The higher Cu % is in speiss, the-more An and Ag are distributed into speiss. Except for a few data, these results comfotm well to the range of distribution equilibria of Au and Ag in matte and speiss systems by Gerlach and Others.

Jan 1, 1980

The unique characteristics of the Target orebody and modernistic approach to mining present significant challenges and a concomitant high potential for new opportunities. The break-away from the traditional labour intensive mining methods improves both safety and productivity significantly. The intention of the paper is to illustrate the application of well known mining methods to the particular requirements of a complex orebody at depth. The evolutionary process followed to establish the final mining method design provides insight behind the finished product, and the modern approach to the planning and service principles equips the reader with a suite of mining engineering ideas.

Jan 1, 2000

By R Hindstr÷m

The demand for iron ore has increased dramatically in the last years and is forecast to remain on a stable high production level for years to come. ItÆs expected that the world economy is facing a stable continuous growth of iron ore to two billion tonnes and more over the next decades (Beddows, 2007). Furthermore it is expected that the existing and known high-grade ore resources will decline, and the iron ore industry will be forced to implement more and more advanced beneficiation plants. As a consequence of the more complex beneficiation requirements, there will be a need for modern solutions for iron ore dewatering that are reliable mechanically as well as cost effective and with high capacity per unit at the same time. Conventional vacuum filtration methods have been the most prevalent in fine iron ore dewatering. Product quality needs, lower ore grades, complex mineralogy and energy costs have resulted in iron ore producers seeking better solutions for dewatering, in particular pelletising feed. New advanced filtration methods have been introduced to the market. This paper describes how these modern methods are answering the needs of the industry. Performance of advanced dewatering technologies (pressure filtration and ceramic capillary action filtration) for iron ore applications has been studied, and the findings are based on both industrial and pilot scale experiences on different materials. For example, the results show that the cake moisture content of iron ore pelletising feed can be optimised more effectively by using modern filtration technologies. By selecting the most suitable and adjustable equipment, the effects of variations of feed material on downstream processes can be minimised and the possibilities of processing more difficult raw materials to high-quality pellets are better. The Larox Corporation develops, designs and manufactures industrial filters and is a leading technology company in its field. Larox is a full service solution provider in filtration for separating solids from liquids. As such, this paper compares the new developments in this market area with the prevailing known vacuum filtration technology, but focuses on a comparison between capillary action filters and rotary vacuum disc filters (RVDF). The trade name CeramecG is used to differentiate the Larox filter from the generic term.

Jan 1, 2007

Downhole survey uncertainties observed at various De Beers operations prompted an investigation into their possible effect on deposit shape and volume. An accurately surveyed artificial æboreholeÆ was constructed and different downhole survey instruments tested. In this way an empirically determined error range of 0.1 per cent to ten per cent was derived for downhole survey data. These survey errors were applied to an orebody model at an existing mine. Visualising the sphere of uncertainty associated with a borehole trace using a general mining package (GMP) gives an indication of possible volume variance. The resulting orebody maximum and minimum volume scenarios for three different depths (200 m, 500 m and 800 m) are presented. For certain instruments and borehole angles, the 3D positional error can be as high as 100 m at 1000 m down the hole. At depths below 200 m the resulting volume deviations can become significant for borehole survey errors exceeding 0.35 per cent. At 800 m depth the volume difference can approach 25 per cent. These figures assume that the error is compounded. The impact of these downhole survey errors is greatest for pipe-like orebodies such as porphyries and kimberlite pipes. Subhorizontal sill-like orebodies (and coal seams) will not be significantly affected by these errors. The impact of this type of survey error needs to be stated (and quantified) and is significant in JORC classification.

Jan 1, 2009

By Gray E, Banks J

In mine site revegetation, exotic grasses are more commonly used than native grasses. This is due to unavailability of native grass seed on a commerical scale and lack of information on agronomical aspects of native grasses. This paper lists a number of native grass species that have the potential to grow well on mine sites, and provides some information on their seed collection, processing and germination. Further, it demonstrates via results of a field trial conducted at Ranger Mine spoil the relative performance of ten native grasses and Rhodes grass. It is concluded that (i) some native grasses have similar ability to grow on mine spoils compared to Rhodes grass and (ii) the use of native grasses have added advantages in ecosystem restoration.

Jan 1, 1994

By Richards JR, Herbert HK

A basic question in preparing this review was how to define sulphur mineral occurrences as being associated with the Pacific Rim. This question will be reconsidered later. The isotope composition of sulphur- containing minerals may be considered in terms of two primary sources - 1. deep- seated sulphur, devoid of crustal contam- ination with a 634S value near 00/0o and 2. oceanic sulphate which fluctuated in value between +10 and +300/00 over geological time (Claypool et al., 1980). However, minerals have seldom been directly derived from these primary sources as even evaporites have been dissolved and reprecipitated. The marine source is differentiated biochemically and isotopically in recent sediments where sulphide from bacterial sulphate reduction may be significantly depleted in 31S. The question of chemical interaction of ascend- ing magma with upper crustal rocks has become one of degree rather than whether or not it occurs. Mineral deposition is considered increasingly in terms of mixing of fluids and their chemical reactions with rocks rather than direct precipitation from magmas or hydrothermal fluids derived from them.

Jan 1, 1987

The great variety of geological conditions in French coal deposits has obliged the industry to develop different thick seam mining methods. In very steep seams in a dense deposit where stowing is necessary to avoid spontaneous combustion, surface subsidence and water problems, a rising horizontal slice method is used, the coal being hard enough and the seams regular (Lorraine). In very thick and irregular steep seams where the stowing is not necessary, a sub-level horizontal slicing is used; a third method has to be used in Dauphine.

Jan 1, 1976

By Kurzeme M, Willoughby D. R

Current research at the CSIRO, Division of Applied Geomechanics, into the mode of response of fill as a structural component has been based on model tests for prediction of behaviour and field observation of critical parameters. The procedure is summarised in four stages: (a) define the specific fill function (b) postulate the mode of failure (c) use models to quantify the conditions (d) monitor critical parameters to check or update the analysis in (c). The above procedure is used to postulate the failure modes of each of the possible func- tions performed by fill materials. Analytical techniques, or lines of investigation, are described for each of these modes and specific reference is made, where, possible, to an exis- ting mine environment.

Jan 1, 1973

By G King, Q Shu, W Cao, F Gyakwaa, H Singh, S Wang, M Huttula, T Fabritius

Metallurgical slag, such as refining slag, is essential to enhance or promote steel cleanliness. The CaO–MgO–Al2O3–SiO2 system is the primary source of oxides-based inclusions. It plays a vital role in applications in various pyrometallurgical processes. Numerous thermodynamic databases and physicochemical properties of slag studies mainly focus on quenched samples and measurements at room temperature. Consequently, the present study explored the physicochemical, structural properties and crystallisation evolution for CaO–MgO–Al2O3–SiO2 glassy slags via in situ hightemperature Raman spectroscopy and synchrotron X-ray diffraction. The study was carried out by synthesising CaO–MgO–Al2O3–SiO2 slag with varying Al2O3/SiO2 ratios. The results from the in situ high-temperature measurement demonstrated a pattern showing a transformation of a broad peak from the glassy matrix to crystalline peaks. The study showed crystallisation of dominant phases such as Ca2SiO4, Ca2Al2SiO7 and CaAl2O4 that correspond and are attributable to changes of structural units during in situ high-temperature measurements. The results further showed a correlation between an increase and transformation in crystalline phases observed from the spectra obtained from non-isothermal heating of the samples.

Jun 19, 2024

The mmmg of alluvial gold involves many deposits of theMesozoic, Tertiary, and Quaternary Ages in processing. Majorfeatures of the composition of such alluvial deposits are the lowcontent of gold and the small size of the gold particles. Atpresent, the gold-miners treat alluvial deposits in which a portionof fme gold (0.25 mm) exceeds 45 per cent. It is expected that by2000 these resources will be the main deposits mined (Zamyatinet aI, 1991).Under real industrial conditions the losses of minus 0.25 mmmetal are 50 per cent and more. The low level of recovery of finegold is observed not only at concentrators equipped with sluices,but also at concentrators equipped with modern diaphragm andpistonless jigs (Table 1).

Jan 1, 1993

By Lyman G. J, Ka

The use of images to determine blast fragmentation is the only feasible technique when one does not want to disturb the production cycle. However, three major problems exist with the use of images. The first is determining real size from a two-dimensional particle, the second is estimating the fines which are missing due to image resolution and particle size range, and the third is proper sampling such that a statistical probability can be calculated for the distribution. Once these problems are resolved, the tedious process of digitizing images by hand may be automated. This paper describes the present techniques used at the JKMRC to "size" blast fragmentation, estimate the missing fines using the Rosin-Rammler equation, determine the sampling error using Gy's sampling equations, and extract the particles from an image using an IBM-AT computer.

Jan 1, 1990

By Boyd G. L

Stress measurement is at the core of most stability design analyses. It is demonstrated that contrary to accepted practice, it is the field measurement, and not the calculated prediction, of stress that requires most examination and review. Since it is not really possible to quantify rockmass properties, the stiffness values used in reduction of stress measurements and in subsequent design analyses (either empirical or numerical modelling) must consider an appropriate range of values.

Jan 1, 1995

By M Byrne, P Newman, M Lindqvist

SomincorÆs Neves Corvo Mine, one of the largest copper producers in Europe, is currently constructing a paste backfill plant in order to replace cemented rockfill in its bench and fill stopes and possibly replace hydraulic sandfill in the drift and fill stopes. A 250 m flow loop was constructed at the mine and the flow properties of various paste blends were investigated. Cycloned tailings and total tailings were both pumped successfully as pastes and were also combined with waste rock for additional testing. The pressure losses in 102 mm and 154 mm diameter pipeline were recorded at flowrates up to 60 m3/hr and are presented at slumps from 120 mm to 250 mm. The data showed the sensitivity of paste mixtures to slight changes in consistency, confirming the need for accurate control during paste production and distribution. The flow results clearly showed the different paste behaviour between cycloned and total tailings pastes and the change in properties at low and high slumps. In addition to pressure loss data, strength testing was done on 38 mm and 82 mm diameter samples. Further strength testing is ongoing at the mine using fly ash as a supplement to cement, reducing the overall binder cost. Preliminary engineering for the underground distribution system is briefly discussed, with reference to the siting of the plant. The Neves Corvo Mine is particularly shallow and alternative methods to pumping were sought in order to ensure sufficient hydraulic head for underground distribution. The comparison of options had to take into account the capital and operating costs, the operation of the plant and the impact on the future expansion of paste fill utilisation at Neves Corvo.

Jan 1, 1998

By A Campbell

Trials of different tapping operations at Olympic Dam have been carried out with the aim of improving the safety of tapping and improving the integrity and lifetime of the taphole. This has involved trialling the use of a mudgun and drill on one of the tapholes of the electric furnace in place of the normal manual tapping procedures. The blister copper tapholes are currently closed using a conical clay plug formed around a steel bar. The plug is pushed into the taphole by hand to stop the flow, and the cooling on the outer part of the taphole freezes the blister copper in the tapping channel. The hole is burnt open using consumable oxygen lances. This puts the furnace technicians in close proximity to molten metal and heat û which is reflected in the safety incidents reported by these operators. By moving to a mudgun and drill operation, the furnace technicians will be moved away from the taphole area improving their safety. Additional benefits include: improved tapping cycles; extended taphole refractory lifecycles; and improved furnace integrity around the taphole, hopefully extending the campaign. This paper outlines the trials that have shown that it is possible to plug and drill blister copper (not matte) tapholes using a mudgun and drill.

Jan 1, 2005

By J F. C L Costa, J C. Koppe

The goal of this study is to characterise co-processed clinkers by identifying the most common minor elements, their distribution in the clinkers and possible effects on the mineralogical properties of the same. The results show the presence of an elevated content of transition metals, especially manganese concentrated in the matrix (up to three per cent) of the clinkers. Anomalous concentrations of arsenic have also been detected, especially at silicate crystal edges. The results indicate that the tracer elements can perfectly be associated to the mineralogical characteristics of the clinkers.

Jan 1, 2008

By Manlapig E. V

ABSTRACT- I Results are given for a series of tests in which a 300 mm pilot-scale Jameson cell has been used in copper recleaner flotation, and for the flotation of a lead rougher feed. the results indicate that the production rate of solids, at the same superficial air velocity Jg, is higher than in conventional columns. Thus in the copper recleaner application, the pulling rate reached 14 gm/cm2/min compared with between two and three for an operating column, while in the lead cleaner application the comparable figures were 12 - 14 gm/cm2/min for the Jameson cell vs 8 - 9 gm/cm2/min for a test column. A froth crowder was used to increase the air superficial velocity Jg in the Jameson cell in the copper recleaner, while holding the collection mechanism and pulp feed rates constant. The recovery increased from 50 per cent to over 90 per cent, suggesting that recovery is controlled mainly by the froth conditions, rather than the particle-bubble interactions in the Downcomer.

Jan 1, 1991

P.IISTRACTThe Pacific Rim is advantaged by the uniqueness and diversity of its geological features. Why then is geology given so little regard in the education systems of the countries of this region? Not that these countries differ greatly from those in other parts of the world. Papers presented during the Precollege Geoscience Education session at the 28th International Geological Congress (28th IGC) held in Washington, July, 1989, indicated strongly that the problem is universal. There is a marked decline in interest in the Earth sciences and many nations are looking towards methods that might change this trend. Problems affecting geological education include the lack of purpose and direction, its obsolete curricula and the difficulty in attracting gifted students.The world-wide plight of geology comes at the very time when it should be fundamental to a public understanding of the global effect of human population pressure. There is a universal awareness of "the environment" but very little awareness of the science that has supplied most of the data. Geology, as the science of the Earth, is of paramount importance to an understanding of our life on this planet, particularly in its role as the source of our every need.

Jan 1, 1990