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Adsorption of Alkylammoniums in the Interlayer of Montmorillonite and its Effect on the Viscosity of Organo-Montmorillonite Gels

Sep 13, 2010

Thank you for your introduction and the opportunity to speak at such an important forum. I feel honoured to be the Tas McKee speaker for this yearÆs conference. I can honestly say that Tas McKee typified the spirit that has ensured the survival of the mining industry despite the modern-day challenges that we encounter. He was one of the most influential people in the New Zealand minerals industry. In 1938, with his father and brother, Tas established Lime & Marble Limited. Over its history, this company evolved from its original base of marble mining to diversify into gold mining and exploration for other industrial minerals, uranium, precious and base metals. He was truly a pioneer that persevered against the odds.   That leads me to the subject of my discussion today. I am going to delve into todayÆs challenges as they apply to gold companies. While we gold miners should be generating record returns, the gold industry shareholder return performance in this buoyant market has barely equalled that of the gold price. It is a dilemma but one that can be resolved with the right strategy.

Jan 1, 2006

The status of remote sensing data availability in New Zealand is outlined and discussed. Currently, two multispectral remote sensing satellites are providing regular data over New Zealand; aircraft scanner services are available from Australia.; operational radar satellite services are yet to materialise. The advantages and disadvantages of the various data types are compared and contrasted. Some image processing considerations are outlined.

Jan 1, 1993

The Ngakuru zeolites are located about 20 km south of Rotorua and comprise a number of deposits dispersed along several fault lines. Relatively recent volcanic activity (250,000 years ago) resulted in ash depositions that vary in depth and mineralogy. Subsequent variable thermal alteration intensities generated predominantly clinoptilolite and mordenite zeolites with a range of physical characteristics. Typically the zeolites have low density (650 kg/m3), have high liquid (60% of dry weight) and odour absorption characteristics, and a high affinity for soluble cations (CEC =: 100 meq/100 g). Traditional kitty litter and oil absorbency markets are being expanded. New opportunities in waste and potable water treatment, organic and synthetic slow release fertilisers, use as a light weight aggregate for speciality concretes, and pozzalome activity are currently being researched.

Jan 1, 2000

By S O. Hille

Modern remote mining operations in Australia are more commonly trending towards fly-in/fly-out (FIFO) sites. This trend is driven by numerous factors including increased business centralisation, reduction in operating costs, and a desire to live in coastal cities that offer closer family networks and a greater diversity of facilities. Consequently, the resource development industry has had to adapt. When WMCÆs Mount Keith Nickel Operation commenced operations in 1994, it was developed as FIFO for its entire workforce. Since then, there have been several permutations of rosters within a 21 day compressed work cycle including the 14/7 cycle. This paper discusses a case study of the change in management process to the 9/5 work cycle focusing on minimising fatigue in the workplace. It includes the discussion of the business case, employee reaction and the practical application. The impact of the best practice change after 18 months is discussed.

Jan 1, 2002

By H Kim, M J. Sun

In order to reduce carbon emissions from the steelmaking process and achieve carbon neutrality, global steel companies are establishing their own medium to long-term strategies and implementation plans using competitive technological advantages held by each steel company. At this point, Hyundai Steel has formulated a product-oriented carbon-neutral strategy based on innovative processing that makes use of Hyundai Steel’s own strength. Based on our experience in electric arc furnace product manufacturing and blast furnace operation in an integrated steel mill, Hyundai Steel is driving the Hy3 (Hy-cube) project, which involves a unique hybrid production system utilising hydrogen and hydrogen-based renewable energy sources. This initiative aims to achieve carbon-neutral production and eventually specialise in producing premium carbon-neutral automotive parts. The project has originality in that it involves not only designing processes using electric furnaces to produce premium steel products such as car body panels and electrical steel sheets, but also aims to reduce carbon emissions from the process, developing carbon-neutral products based on market demand. To assess the feasibility of the Hy3 project, Hyundai Steel conducted two pilot productions. The first pilot was producing a prototype of lower-arm part using electric arc furnace with three different kinds of raw materials: molten iron, HBI (hot briquetted iron), and scrap. Successful performance evaluation of auto parts with 1 GPa strength was achieved. The second pilot has been focused on tire cord steel, with the first-phase tests yielding a 33 per cent reduction in carbon footprint (CFP). Using the advantages of operating experience in electric arc furnace, Hyundai Steel is preparing for test operations producing various automotive parts using an electric arc furnace (EAF) to advance the Hy3 concept. From a medium to long-term technological development perspective, Hyundai Steel’s blueprint includes producing high-end carbon-neutral steel products using hydrogen-reduced iron as raw material.

Jun 19, 2024

By T J. Napier-Munn, T Perkins

The JK Drop Weight test was developed at the Julius Kruttschnitt Mineral Research Centre (JKMRC) in the early 1990s as a means of characterising ore for the purposes of AG/SAG mill and crusher modelling. It has since been used extensively worldwide in the minerals industry as a key ore characterisation test which produces parameters which are used in comminution circuit design and optimisation. The test generates three parameters which are used in the AG/SAG mill model of the JKSimMet software. The resistance of the ore to high energy (impact) breakage is quantified with the A and b parameters. The oreÆs resistance to low energy (abrasion) breakage is measured using the ta parameter. The accuracy and precision of the results of the JK drop weight test are of great importance given that the parameters are key inputs in the design of such capital intensive items as SAG mills. Plant optimisation exercises also rely on the accuracy of the parameters to assist with improving the performance of an existing circuit. A thorough analysis of the accuracy and precision of the parameters generated by the JK drop weight test has now been undertaken by JKTech Pty Ltd (JKTech). An experimental program was designed using statistical methods to plan a hierarchical set of 24 drop weight tests on homogeneous material. Each stage of the test was identified and incorporated into the experimental design so that the contribution to the overall error of each stage could be quantified, including the effect of operator. The data were analysed by nested analysis of variance. An overall analysis of the A, b and ta parameters generated from the test program has now quantified the variance of these parameters more thoroughly than ever before. Using the results for the impact parameters, an analysis has been carried out to investigate the effect of these variances on final SAG mill comminution circuit design. The results will also be used to refine the comparative testing procedures currently in use by licensees worldwide.

Jan 1, 2008

By P E. H Gregg, R B. Stewart

Restoration trials established in 1985 included a treatment where pasture seed was sown directly into fertilised tailings. After seven years, accumulated soil data was used to compare physical and chemical changes in the plots with the original tailings control area nearby.   A known amount of annual fertiliser additions over the seven year period allowed nutrient balances to be calculated. Losses of S and P were relatively high at 72% of applied S and 28% of applied P. Calculations show that at least 240 kg N/ha/yr was fixed by clovers and this is likely to be under-estimated given that the calculation did not allow for leaching losses.

Jan 1, 1993

A critical appraisal of the wide variety of processes used in the pyrometallurgical production of metals and non-metals shows that there is a strong physico-chemical and, in particular thermodynamic, basis for the variety. Based on this, a simple classif- ication scheme has been developed which makes it possible to understand the methods for extracting individual metals and non-metals pyrometallurgically and to assess which are the more attractive routes. The analysis presented shows why there are essentially two broad routes for pyrometallurgical production of metals and non-metals; viz., the reduce- refine and the refine-reduce routes. Halides have the role in pyrometall- urgical processing of producing pure compounds for subsequent reduction. The criteria which determine the selection of reduction method for oxide raw materials and intermediate halides (e.g., use of carbon, hydrogen, a more reactive metal or electrowinning) are examined critically in the paper. The treatment of sulfide raw materials is considered also, particularly the criterion for smelting sulfides directly to the metal.

Jan 1, 1987

By G Maude, R Ayres, R N McLean, N A. Reynolds

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Mabilo copper-gold-magnetite skarn deposit is located in southern Luzon in the Paracale mineral district, where iron has been produced historically from several skarn deposits. Mabilo occurs in the south-west of the district and is distinct and significant because of its high grades of copper and gold compared to historical mines.The Mabilo licence surrounds the Venida prospect, where past small-scale mining has exploited iron, copper and gold mineralisation in oxidised skarn. A ground magnetic survey in 2007 defined a number of strong anomalies under Quaternary volcanic cover south of Venida. The property was acquired by Sierra Mining Ltd in 2011, the magnetic data were remodelled and drilling commenced in September 2012. Diamond drill hole MDH001 targeted the strongest anomaly, which was 500 m south of Venida and under 20 m of volcanic cover. It intersected 94 m with an average grade of 2.2 per cent copper, 1.6 g/t gold and 36.6 per cent iron. Subsequent drilling was targeted by magnetic modelling, incorporating magnetic susceptibility data from drill core, which resulted in a high percentage of successful drill holes.The mineralised skarn preferentially replaces a dipping limestone unit within an Eocene sequence dominated by volcanic siltstone and sandstone, metamorphosed to marble and hornfels in the aureole of a Miocene quartz-diorite intrusion. Skarn occurs discontinuously along the eastern and southern diorite contact, controlled by primary sedimentary facies variation, structural geometry, fault offsets and intrusive contacts.Coarse magnetite skarn with garnet and minor wollastonite and clinopyroxene contains variably abundant chalcopyrite and minor molybdenite. Magnetite skarn occurs in sharp contact with unaltered marble or grades into garnet skarn with minor chalcopyrite. Structurally controlled retrograde skarn alteration is strong to intense and is characterised by bornite, clinozoisite, iron carbonate and chlorite. The retrograde skarn is weakly overprinted by late-stage pyrite veining and brecciation associated with clay-silica alteration with arsenopyrite and tetrahedrite-tennantite.The quartz-diorite stock is interpreted as the source of the prograde skarn-forming and mineralising fluids. Late-stage porphyritic intrusions in the contact zone indicate continuing magmatism during uplift, when telescoping led to a high-level, high-sulfidation overprint. This suggests the potential for deeper porphyry-style mineralisation.CITATION:Reynolds, N A, Ayres, R, McLean, R N and Maude, G, 2015. The Mabilo copper-gold-iron deposit – a new skarn discovery in the Philippines , in Proceedings PACRIM 2015 Congress, pp 431–438 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Completion of a project requires two separate money-focused activities, namely economic evaluation of the cash flows underlying the project (before financing) and if the economics look promising, how it can be financed. Economic evaluation might be best led by a person with a technical-operating background, whereas financing might be best led by an accountant. Both should be presented in simple language with easy to understand models. Economic evaluation has a sad and bad history because it evolved from the fringes of accounting. Anyone can become a self-appointed practitioner. Some still take pride in mathematical complexity without realising that they distance themselves from the decision-makers and alienate other team members. Today there is no evaluation modelling consistency across the mining industry and this reflects poorly on our discipline. It is not tolerated amongst our peers in engineering and accounting. In 2009 æbest practiceÆ economic evaluation modelling is well defined. It is:easy to follow;tailored to its purpose;transparent;discipline, rigour and consistency;recording of all source data; and hencequick to audit. Mantra: If you cannot readily understand my model you do not have a problem, I do! The task of the economic model is to make the range of business cases underlying the decision easy to understand. Intellectual power is used to simplify the decision to its key issues and risks and to present the full range of possible business outcomes in readily understood terms. Project team members, management and the board must be able to make their decisions with æeyes wide openÆ. A steering committee should be established to develop a set of standards and practices that could be adopted for economic modelling within the industry. The industry needs to purge itself of the undisciplined economic evaluation modelling that now characterises the discipline.

Jan 1, 2009

By Wilson A. F

The use of stable isotopic measurements as a technique for elucidating the origin and history of the water in hydrothermal fluids is relatively new. Recept studies have emphasized the importance of meteoric water in the formation of many hydrothermal ore deposits including many epithermal gold-base metal deposits which occur in faulted volcanic terrane. Other vein-type gold ores are believed to have formed from fluids of magmatic or metamorphic origin and exhibit characteristic d18O values. Preliminary oxygen and carbon isotopic data for some important gold deposits of eastern Australia have emphasized the diverse origins of their ore fluids.The Mount Morgan gold-copper orebody is shown to be of the volcanogenic massive sulphide type with ore fluids predominantly of sea water origin. The Charters Towers fissure veins formed during hydrothermal activity associated with intrusion of Lolworth Igneous Complex equivalents. Oxygen isotopic studies of the quartz reefs at Stawell and Gympie have been inconclusive. The ore fluids have a d18O value of about 7 per mil and may be of magmatic or metamorphic derivation.

Jan 1, 1981

By M J. Begbie, K B. Sporle

The Golden Cross low sulfidation epithermal deposit produced approximately 750,000 ounces of Au from two ore zones: the underground Empire Vein System and the open pit stockwork. The Empire Vein System has at least eight stages of vein formation: (1) sulfide veins, (2) black veins, (3) massive veins, (4) banded veins, (5) thin white veins, (6) crumbly veins, (7) massive/platy calcite veins, and (8) flattened rhomb calcite veins. Gold mineralisation occurred relatively early in the lifetime of the system, dominantly during 2 through 4. The late calcite veins (7 and 8) and early sulfide veins (1) are barren. The vein system formed in a dominantly extensional environment, though some compressional faulting may have also existed during vein formation. There is no evidence for significant strike-slip faulting during vein formation, highlighting the fact that explorationists should pursue on-site structural patterns rather than fashionable models.

Jan 1, 1998

A commercial Philips X-ray Fluorescence (X.R.F.) analyser was converted to an experimental instrument suitable for determination of the accuracy to be expected of X.R.F. on line analyses of concentrator slurries. Problems with stability of slurry sample presentation were eliminated by a number of minor modifications.By the use of multiple linear regression techniques instrument calibration equations including error terms were determined for copper flotation feed slurries. Results indicated that the accuracy of copper and iron analyses of flowing slurry samples could approach that of static pressed powder samples.Possible means of reducing the error terms to a level of at least that of pressed powdel' samples involve alternative methods of compensating for the per cent solids in the slurry, Design is under way for installation of a plant unit.

Jan 1, 1968

Grey River Gold Mining Ltd commenced dredging alluvial flats in the Grey River Valley in 1989. Previous drilling indicated over 100 million cubic metres of gravels with some 90 per cent of the gold in the bottom seven metres. The dredge built by Rahco, Spokane, was innovative in a number of aspects but particularly in the fact that a separate ladder with a cutter and pump was used to strip the overburden and a bucketline to mine the gold bearing wash below. Metallurgical studies and exploration were initiated when the project commenced. Leasing and environmental considerations were investigated and action taken. While progress is being made, the operation at this stage is not meeting required production and performance. Main problems have been with the stripping system and wear.

Jan 1, 1990

By V M. Silva, P A. A Martins, V O. Matthew, A L. S Fonseca, E B. Cunha, A J. D Ferrari, E M. S Silva, A C. Silva, D R. T Vilela

The Anglo American phosphate mine is located in the Brazilian state of Goiás and possesses one of Brazil’s most important phosphate rock deposits, with the site being the country’s second largest producer of phosphate rock concentrate. Despite the site having been in operation since 1979, the mining team only started using explosives in 2004 when rocks with greater hardness started to appear in the mine’s geological profile. Rock excavation was previously performed mechanically. Until 2013, only rocks with high hardness were blasted, this following the standard drilling grid that was defined in 2004 without any changes in the blast parameters. The aim of this paper is to show how fragmentation optimisation has yielded positive results at all stages of the production chain, from the mine to the mill passing through an impact hammer crusher, a rod mill and ball mill, operating in close circuit with hydrocyclones.While incorporating the mine to mill holistic approach during the operational integration, the focus was on defining the blasting domains and respective optimal fragmentation and measuring the benefits of blasting in terms of reduction in energy and grinding media consumed in the comminution processes. In the first stage, the blasting team made changes to the blasting parameters and assessed the effects of these changes on fragmentation using computer software and on-site measurements. This generated a database that made it possible to divide the mine into blasting domains. For the second stage, teams from the plant, geology, mine planning and operation departments jointly made comparisons between the performance when processing stockpiles, which only included high hardness blasted ore (20–30 per cent of blasted ore). Changing the drilling grid’s size from 3.0 m × 3.8 m to 2.0 m × 2.6 m for high hardness rock with the presence of silicates resulted in a 40 per cent reduction in the P80 for the blasted material (from 459 to 278 mm), while changing the grid from 3.0 m × 3.8 m to 2.6 m × 3.2 m for high hardness rock without the presence of silicates generated a reduction of 25 per cent (from 270 to 204 mm). There were gains observed from the measurements at the mineral processing plant in terms of specific energy spent on comminution and on the consumption of grinding bodies in the rod mill. There was a measured reduction of circulating load during secondary grinding and a reduction in slime generation.CITATION:Silva, A C, Martins, P A A, Silva, E M S, Fonseca, A L S, Ferrari, A J D, Cunha, E B, Silva, V M, Matthew, V O and Vilela, D R T, 2015. Fragmentation optimisation – adopting mine to mill for reducing costs and increasing productivity, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 363–368 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By P Steinier

Most operations, when considering their comminution circuit, are primarily concerned with achieving the desired particle size distribution to obtain adequate liberation for the separation process, at minimum cost. Invariably, the effect the grinding media has on the subsequent separation process (ie flotation, leaching) is not taken into account when selecting the media. This choice is driven by cost rather than metallurgical outcomes. Maximising valuable mineral recovery, with optimum selectivity against gangue minerals, is about good particle preparation. And, particle preparation is strongly related to achieving adequate mineral liberation with the correct pulp chemical conditions. However, the pulp chemistry of a system is largely ignored and relies heavily on pH control and the addition of appropriate reagents (collectors, frothers, activators, depressants). The changes effected by the addition of the various reagents are obtained through conditioning the ground pulp prior to or during the concentration stage, subsequent to grinding. Frequently, reagents are added during grinding with good effect, but the impact of the grinding media on down stream processing is usually overlooked. A number of case studies examining the effect of grinding media on pulp chemistry and subsequent flotation performance were completed on several different sulfide mineral systems (for example, lead/zinc, copper, refractory gold). The evidence suggests that a change in grinding media type from forged to high chrome (ie conditioning the pulp during grinding) resulted in a shift in pulp Eh to less reducing conditions, an increase in the dissolved oxygen content of the pulp and a reduction in the iron species present. The changes have a positive impact on flotation behaviour. The results of the case studies are discussed.

Jan 1, 2004

By R Jones

OneSteel Whyalla’s grate-kiln-cooler pelletising plant was commissioned in 1968 processing haematite feed from the local South Middleback Ranges mining area. The existence of a magnetite resource beneath the haematite ore at Iron Duke had been known for some time. In 2004, a decision was made to covert the primary iron source for the Whyalla steelworks from haematite to magnetite – known as project magnet. The intent of the project was to convert the feed to the steelworks from haematite to magnetite and to free up the remaining haematite resource for export. The pelletising plant was cut over to a magnetite feed in 2007.The thermochemical differences of magnetite compared to haematite are threefold:1. the introduction of an exothermic reaction during conversion of magnetite to haematite,2. the absence of bound water which existed within the haematite, and3. lower gangue content requiring lower fluxing levels and therefore lower calcination energy demand.The combination of these differences results in a significantly different induration requirement for magnetite as compared to haematite. The change therefore required extensive research and test work to design modifications to the furnace and to ensure appropriate risk mitigation for the Whyalla steelworks.Preliminary pot-grate test work was performed to define the pellet chemistry and confirm the suitability of the magnetite to produce pellets suitable for the OneSteel blast furnace. A heating curve was developed by use of computer-based heat and mass balance modelling. Extensive pilot scale grate-kiln-cooler test work was then performed to confirm the heating curve and to verify and fine-tune the pellet properties. Computation fluid dynamics was used to design the physical changes to the furnace required to achieve the proposed heating curve.Following installation of an additional preheat zone, including a wall and dilution air fans, into the preheating furnace, and installation of an additional wall into the cooler, the modified furnace was commissioning in December 2007. The plant performed as expected during commissioning with the actual heating curve matching the proposed curve and the produced pellets within blast furnace specifications.

Jul 11, 2011

By Watsford RMS, Schache IS, Slaughter PJ

As part of the overall Copper Smelter expansion activities at Mount Isa Mines from 1970 - 1975, a decision was made to open circuit the converter slag from the Smelter and treat this product by flotation. This paper describes the technical aspects of plant operating and reagent practices employed, with particular emphasis on the large scale milling of this product and the effect through the use of reagent hydroxy ethyl cellulose on chalcocite grade and recovery.

Jan 1, 1978

By M Svartsjaern, D Saiang and K Mäkitaavola

The Kiirunavaara mine is a large-scale (28 Mt/a) iron ore mine located in northern Sweden. The mine is owned and operated by Luossavaara-Kiirunavaara Aktiebolag (LKAB) using sublevel caving (SLC). The SLC area underlies an open pit decommissioned in the 1950s, the current main SLC haulage level is situated at an depth of 1100 m. The main orebody dips 60 degrees to the east with a distinct boundary defining the hanging wall to the east and footwall to the west. Since the 1980s damage has been observed both in the footwall rock mass as well as on the footwall crest of the open pit. Recent investigations indicate that the underground footwall damage is primarily controlled by large-scale slope failure mechanisms. Structurally controlled near-vertical planar shear failures in the upper footwall appear to be driven or facilitated by a step-path like curved shear failure situated in a zone starting ca 250 m, and intersecting the SLC about 100 m above the active mining level. To confirm this failure evolution a pilot underground measuring system has been designed and installed to monitor the expected rock mass displacements indicated by numerical models based on the above mechanisms. The systems consists of 50 m time domain reflectometry (TDR) coaxial cables installed in the footwall both across and away from an estimated damage extent boundary to monitor shear movements along natural joint surfaces. The TDR installation is combined with long extensometers to facilitate differentiation between diffuse shear and rock mass normal expansion. Additionally, a low-tech system of tape extensometer lines are installed in drifts and stopes running perpendicular to the ore strike to monitor horizontal displacements in the infrastructure as the footwall ‘slope’ loses confinement during mining advance when the mined out areas are replaced by caved rock from the hanging wall.CITATION:Svartsjaern, M, Saiang, D and Mäkitaavola, K, 2016. Underground footwall monitoring at the sublevel caving mine – Kiirunavaara, Sweden, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 773–780 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016