Mark Aylmore - Academia.edu (original) (raw)

Papers by Mark Aylmore

$Research paper thumbnail of Outcomes of the International Union of Crystallography Commission on Powder Diffraction Round Robin on Quantitative Phase Analysis: samples 2, 3, 4, synthetic bauxite, natural granodiorite and pharmaceuticals$

Journal of Applied Crystallography, Jul 18, 2002

The International Union of Crystallography (IUCr) Commission on Powder Diffraction (CPD) has spon... more The International Union of Crystallography (IUCr) Commission on Powder Diffraction (CPD) has sponsored a round robin on the determination of quantitative phase abundance from diffraction data. The aims of the round robin have been detailed by Madsen et al. [J. Appl. Cryst. (2001), 34, 409±426]. In summary, they were (i) to document the methods and strategies commonly employed in quantitative phases analysis (QPA), especially those involving powder diffraction, (ii) to assess levels of accuracy, precision and lower limits of detection, (iii) to identify speci®c problem areas and develop practical solutions, (iv) to formulate recommended procedures for QPA using diffraction data, and (v) to create a standard set of samples for future reference. The ®rst paper (Madsen et al., 2001) covered the results of sample 1 (a simple three-phase mixture of corundum,¯uorite and zincite). The remaining samples used in the round robin covered a wide range of analytical complexity, and presented a series of different problems to the analysts. These problems included preferred orientation (sample 2), the analysis of amorphous content (sample 3), microabsorption (sample 4), complex synthetic and natural mineral suites, along with pharmaceutical mixtures with and without an amorphous component. This paper forms the second part of the round-robin study and reports the results of samples 2 (corundum,¯uorite, zincite, brucite), 3 (corundum,¯uorite, zincite, silica¯our) and 4 (corundum, magnetite, zircon), synthetic bauxite, natural granodiorite and the synthetic pharmaceutical mixtures (mannitol, nizatidine, valine, sucrose, starch). The outcomes of this second part of the round robin support the ®ndings of the initial study. The presence of increased analytical problems within these samples has only served to exacerbate the dif®culties experienced by many operators with the sample 1 suite. The major dif®culties are caused by lack of operator expertise, which becomes more apparent with these more complex samples. Some of these samples also introduced the requirement for skill and judgement in sample preparation techniques. This second part of the round robin concluded that the greatest physical obstacle to accurate QPA for X-ray based methods is the presence of absorption contrast between phases (microabsorption), which may prove to be insurmountable in some circumstances. research papers 384 Nicola V. Y. Scarlett et al. Quantitative phase analysis

Mining, metallurgy & exploration, Nov 1, 2001

Thiosulfate offen a nontoxic alternative to cyanidefor proCl'ssing gold ores. The mechanism o(lea... more Thiosulfate offen a nontoxic alternative to cyanidefor proCl'ssing gold ores. The mechanism o(leaching gold using ammoniacal thiosu(fate solution is driven hy the Cu(II)-Cu(I) redox couple and is complicaled hy competing ligands such as NH 3 and S20/'. It is shown that an understanding of the copper specialion (//1(/ sulfur speciation is required to optimize this system. This paper presents Eh-pH and speciatiol1 diagramsf(Jr varying concentrations of Cu(11), S20./" and NH 3 and discusses the COllditions under which l'lIriou.1 copper and sulfur species are stahle.

Hydrometallurgy, Mar 1, 2014

ABSTRACT The effect of some typical oxide and sulfide minerals, as well as activated carbon, on s... more ABSTRACT The effect of some typical oxide and sulfide minerals, as well as activated carbon, on synthetic gold thiosulfate leach solutions was examined. The presences of pyrite and goethite in synthetic ore slurry will have a significant effect on the adsorption and stability of gold, silver, copper and polythionates in ammoniacal thiosulfate solutions. Adsorption of tetrathionate in particular leads to significant gold and silver losses. The adsorption of copper on mineral surfaces inhibited gold and silver loss, even in the presence of tetrathionate. However, goethite was found to strongly adsorb copper(II). It is concluded that gold extraction from natural ores is lower than that obtained with cyanide, partly as a result of sorption or precipitation reactions. Furthermore, the presence of silver in solution catalyses the precipitation of a mixed copper/silver/gold sulfide in ammoniacal thiosulfate solutions containing tetrathionate.

European Journal of Solid State and Inorganic Chemistry, Dec 1, 1996

Despite over a century of resource development experience in Western Australia, the downstream pr... more Despite over a century of resource development experience in Western Australia, the downstream processing of hard rock lithium deposits is a relatively new industry. This project has shed light on the of WA lithium deposits, and provides a new geometallurgical framework applicable to mining and processing optimisation.

This landmark publication distills the body of knowledge that characterizes mineral processing an... more This landmark publication distills the body of knowledge that characterizes mineral processing and extractive metallurgy as disciplinary fields. It will inspire and inform current and future generations of minerals and metallurgy professionals. Mineral processing and extractive metallurgy are atypical disciplines, requiring a combination of knowledge, experience, and art. Investing in this trove of valuable information is a must for all those involved in the industry-students, engineers, mill managers, and operators. More than 192 internationally recognized experts have contributed to the handbook's 128 thought-provoking chapters that examine nearly every aspect of mineral processing and extractive metallurgy. This inclusive reference addresses the magnitude of traditional industry topics and also addresses the new technologies and important cultural and social issues that are important today

World Gold 2019 Conference Proceedings No6/2019, 2019

The Commonwealth Mine project area comprises the historical base metal-gold Commonwealth Mine, Co... more The Commonwealth Mine project area comprises the historical base metal-gold Commonwealth Mine, Commonwealth South gold deposit and more recently the Silica Hill deposit. They are located 100 km north of Orange in New South Wales, Australia. Impact Minerals Limited has discovered high grade mineralization of gold, silver, zinc, lead and copper which occurs in massive sulphides with extensive pyrite, veins of sulphide and quartz and disseminated sulphide in a variety of sedimentary and volcanic host rocks. The Inferred Resource has been defined comprising of 720,000 tonnes at 2.8 git gold, 48 git silver, 1.5% zinc, 0.6% lead and 0.1 % copper. The overall aim is to establish the metallurgical characteristics of these ores and development an appropriate flow sheet to allow future mining operations at this prospect. The mineralogy of a suite of representative samples of the various ore types were characterised using advanced analytical and mass spectrometry techniques available at the John de Laeter Centre at Curtin University to identify metal deportment, mineral associations and liberation characteristics of both ore-bearing and gangue minerals.• Diagnostic leaching tests were carried out to determine the reactivity of minerals and the availability of metals to extraction processes by both conventional cyanide leaching and Curtin University's patented glycine leach technologies. The benign nature of glycine and atmospheric leaching conditions make it a potential favourable leaching option in treating such ores,.particular in sensitive areas where cyanide usage is discouraged. This paper describes the findings of this study

Various processes have been developed using a combination of elevated temperature and chemical tr... more Various processes have been developed using a combination of elevated temperature and chemical treatment processing to recover Li from silicate minerals. To facilitate further process development, a comprehensive understanding of the deportment of Li and associated minerals in ore bodies is essential to allow the industry to predict the response of ore reserves to metallurgical treatment options. This paper describes results from the integrated use of the John de Laeter Centre’s state of the art analytical and mass spectrometry techniques to characterise a selection of Li bearing ore bodies and determine their amenability to potential processing options for the extraction of Li. The mineralogy, mineral associations, and liberation characteristics of ore-bearing and gangue minerals were characterised using a combination of the TIMA and XRPD studies. The Li content and distribution within minerals were defined using LA-ICPMS and field emission scanning electron microscopy techniques (...

Procede servant a lixivier des metaux precieux tels que de l'or provenant d'un minerai, t... more Procede servant a lixivier des metaux precieux tels que de l'or provenant d'un minerai, tel qu'un minerai sulfure. Ce procede consiste a broyer le minerai contenant le metal precieux, de maniere a obtenir un minerai broye, a mettre en contact ce dernier avec de l'eau, un reactif alcalin, une source d'oxygene appropriee et une source de soufre appropriee (pouvant etre le minerai lui-meme) en quantites suffisantes pour generer au moins 0,02 mol/L de thiosulfate in situ, et a lixivier le minerai broye afin de produire une phase aqueuse contenant thiosulfate. Le thiosulfate genere in situ peut constituer au moins 30 % du thiosulfate necessaire pour effectuer l'extraction du metal precieux dans la phase aqueuse. Ce procede permet de generer sur place, en totalite ou en partie le thiosulfate necessaire pour effectuer la lixivation du metal precieux, ce qui permet de limiter ou d'eliminer les couts et les difficultes potentielles associees a l'apport separe ...

$Research paper thumbnail of Evaluating Process Options for Treating Some Refractory Ores$

A significant contemporary challenge for gold mining companies is to define economic process opti... more A significant contemporary challenge for gold mining companies is to define economic process options for treating more complex ore bodies as the less refractory ores become depleted. Demonstration of economic treatment options allows gold companies to maintain and increase their ore reserves. The selection of options to treat a specific ore is significantly impacted by factors such as mineralogy, precious metal grades and deportment, gold to sulphur ratios and hazardous impurities. Bateman Engineering has carried out a number studies to help mining companies evaluate further the potential for developing ore bodies. This paper provides two examples of work to evaluate the potential for treating a low grade ore with high carbonate and arsenic content and an ore with high silver grade. Capital and operating cost estimates for different methods of pretreatment were prepared and these estimated costs and ore sulfide grades then used to compare the process economics.

Goldschmidt2021 abstracts

Geology

Mining of “invisible gold” associated with sulfides in gold ores represents a significant proport... more Mining of “invisible gold” associated with sulfides in gold ores represents a significant proportion of gold production worldwide. Gold hosted in sulfide minerals has been proposed to be structurally bound in the crystal lattice as a sulfide-gold alloy and/or to occur as discrete metallic nanoparticles. Using a combination of microstructural quantification and nanoscale geochemical analyses on a pyrite crystal from an orogenic gold deposit, we show that dislocations hosted in a deformation low-angle boundary can be enriched in Ni, Cu, As, Pb, Sb, Bi, and Au. The cumulative trace-element enrichment in the dislocations is 3.2 at% higher compared to the bulk crystal. We propose that trace elements were segregated during the migration of the dislocation following the dislocation-impurity pair model. The gold hosted in nanoscale dislocations represents a new style of invisible gold.