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By B Reid

"Since the commencement of mining operations at the Cowal Gold Operations (CGO) in 2005, reverse circulation (RC) drilling has been the preferred method for grade control (GC) sample collection. This method was selected because it allowed:for multibench drilling (20 m hole depths for two benches of mining) to aid mine planning increased data density for comparison against the wide spaced ore reserve model angled drill holes to intersect perpendicular to the strike and dip of the shallow dipping mineralisation ability to take two metre sample intervals to enhance the understanding of the mineralisation’s short-scale variability and provide the ability to flitch mine.From June 2008 to December 2013, RC GC was performed using a UDR rotary cone splitter. The field duplicate data over the period displayed strong precision, with a correlation coefficient of 0.94 and an average relative per cent difference (RPD) of 21 per cent for gold. Up to 66.1 per cent of field duplicate data greater than 0.1 g/t fell within ±20 per cent RPD. This is within limits of industry best practice. The Mine to Mill reconciliations over the same period showed the estimated GC grade was 7.7 per cent lower than the calculated head grade (CHG).In December 2013, the Progradex sampling system (PGX) was introduced at CGO due to its advertised ability to capture 100 per cent of the drill cuttings for the complete sample interval, inclusive of fines. Analysis of field duplicate data indicates that since the introduction of the PGX, the sample precision has drifted. From January 2014 to February 2016, the correlation coefficient was 0.92 and up to 51.2 per cent of field duplicate data, greater than 0.1 g/t fell within the ±20 per cent RPD. Over the same 26 month period, the Mine to Mill reconciliation improved to one per cent lower than the CHG. Granulometric analysis of the RC samples collected from the PGX indicated the fines material(<212 µm) averaged up to 22 per cent of the samples mass and following assay determination, the fines material represented a weighted average of 31 per cent of the total gold content within the sample.This paper highlights the:importance of the complete capture of all drill cuttings during an RC drill programinfluence of fines material on the sample quality and accuracyimpact sampling of the fines material has on the Mine to Mill reconciliation performancechallenges experienced in commissioning a PGX system.Citation:Reid, B, 2016. A Fine Looking Sample - the Importance of Fines in Grade Control Sampling to Mine to Mill Reconciliation, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 28–38 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

Mr. Murray said: Having recently returned from a visit to America, it may be of interest to members to hear something from me of the mining fields and metallurgical works which I had the opportunity of seeing, and the impressions which I formed concerning general practice and conditions there, as compared with our Australian standards in the mining industry, and in matters generally.The most striking feature of the North American continent is thehuge plan upon which Nature has built, the multiplicity of immense mountains, rivers, and lakes, the snow-covered tops of the former forming reservoirs for the latter during the summer months, being most impressive to the Australian visitor. Starting from Vancouver I travelled east for over 500 miles through the wonderful Canadian...

Jan 1, 1927

The distribution of tin and iron between slag and metal phases at about 1150°C was studied in pot scale experiments. The distribution coefficient k = (Sn/Fe) In metal X (Fe/Sn) in slag was found to vary from about 300 for metal corresponding to nearly pure tin, to about 100 for metal of about miscibility gap composition (17' 4 per cent Fe). Results conformed reasonably well to a straight line relationship between log k and (l-2NFe), as expected on theoretical grounds, and are consistent with thermodynamic data for the Fe-Sn phase diagram and the reaction Fe + SnO = FeO + Sn.Calculations are presented indicating the feasibility of smelting low-grade tin concentrates in a two-stage counter-current reduction process.

Jan 1, 1966

The Archaeozoic Willyama Complex at Broken Hill has suffered several periods of deformation and metamorphism. New structural and petrological information together with that available from the literature gives a picture of the metamorphic evolution of the Barrier Ranges. Several epochs of metamorphism are recognized, and potassium-argon dating of minerals has been applied with limited success to the resolution of these epochs.INTRODUCTIONAdvancements in the mineral industry at Broken Hill over the past eighty years have been accompanied by a continual striving towards increased understanding of both the geological history of the Barrier Ranges and the environment of the Broken Hill ore deposits. However, although many detailed studies of selected localities and particular-aspects of Broken Hill geology have been carried out recently, the regional geology of the Barrier Ranges as a whole has received little attention from a petrological viewpoint since the pioneer investigations of Mawson (1912) and Browne (1922). There still remains a great need for regional surveys combining field studies of the habits, structures and outcrop relationships of the various rock types with laboratory investigations of their chemistry, mineralogy and microscopic ,fabrics. Recording observations arising from three brief visits to the Broken Hill area during 1959 and 1963 may stimulate further surveys.During one of these visits, the generosity of the Zinc Corporation Limited in providing field transport and geological guidance enabled the writer to collect material and study field relationships and appearance of the various rock types at numerous localities covering most of the Willyama outcrop. A complete study has not been conducted...

Jan 1, 1963

By Y G. Anoman

This paper discusses the operating model within Endeavour Mining Corporation regarding the options of owner mining against contract mining. It’s based on the concept of ‘are we carrying out the most efficient mining’ regarding cost and performance. This question can only be answered through an extensive contract mining tender process and conducting a comprehensive comparison to evaluate the transition viability. Karma mine, located in Burkina Faso, is the subject of this paper. The Tender model included sales of equipment, parts and tooling associated with the traditional Load and Haul Schedule of Rates (SOR). The methodology focused on the structure of the tender process, which consists in the development of a SOR based on haulage profiles and mining schedule. This is a new Endeavour framework that allowed the bidders to compete on an even level. This was performed using a systemic analysis which encompassed all the elements involved in a transition such as the Human Resources (HR), taxes and customs implications, directs and non-direct costs (Finance and interest on assets, depreciation, insurance), contractor risk profiling. It was assessed against the normalised internal pricing tender-based. This paper gives an insight into how a West African mining operation addressed the sensitivities of the HR functions against the commercial aspects. This was one of the most successful transitions in West Africa and was carried out during the COVID crisis. The outcome of this project has created value by detailing a lesson learned model for both commercial and HR aspects. This discusses the commercial comparisons along with the internal model with the underlying HR functions as a risk factor that could have jeopardised the continuation of the operation. This resulted in a smooth transition with the additional cash flow generated by the sale of the parts and equipment turned Karma into a viable operation.

Jun 22, 2022

Mechanism Responsible for Flocculation in Poly (N-Isopropylacrylamide) Temperature Responsive Dewatering - Attractive Interaction Forces Induced by Surface Hydrophobicity

Sep 13, 2010

By L Edwards, M Haest, D Mittrup

The focus in the iron ore industry has shifted from increasing production volumes with less regard for cost, to efficient production of quality tonnes. BHP Billiton iron ore geoscience and exploration has embedded infrared spectroscopic sensing of drill hole samples to help meet this challenge.Infrared spectroscopy is delivering mineral predictions that are used for (automated) geology logging and modelling. The spectra are processed together with other available data sets to predict geometallurgical and geotechnical variables that include lump per cent and uniaxial compressive strength.Trials are ongoing to test the benefit of infrared spectroscopy during mining, including the analysis of grade control samples and remote sensing of mine faces. Results show great benefits in the fields of short-term geology modelling, better understanding of material (handling) properties, identification of geotechnical risk areas and high resolution ore-waste delineation.These trials are bringing BHP Billiton iron ore closer to its ultimate goal of having infrared spectroscopic data collected across the mining value chain. Once such data are available everywhere, regression models can be trained at one point (eg iron grade model trained on exploration samples) and be applied elsewhere (eg iron grade predicted on mine faces). Such predictive analytics will enable not only high precision mining, but also provide maximum time to tailor plant design to the ore in the ground, based on learnings from ores processed in other plants. This will improve planning outputs that will eventually increase mining efficiency, processing capability and product quality.CITATION:Haest, M, Mittrup, D and Edwards, L, 2017. Infrared spectroscopy in BHP Billiton iron ore with a focus on in-mine infrared sensing, in Proceedings Iron Ore 2017, pp 549–556 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

The range of environments which control the level of ground support required vary greatly in terms of rock type, rock structure and the mining method used. At the operating mines visited during this review the level of ground support was such that incidence of rock-fall- related accidents were rare. It was also found that methods existed to support most of the conditions encountered. The main problem areas were weak rock, major geological structures, areas of heavy jointing, high development density and areas affected by high mining-induced stresses and blasting. With stope support the level of success was much lower than that achieved in development; the larger spans and more rapid changes in geometry of open stopes compared with cut and fill stoping (where cables were originally used) led to significant problems. Before a useable design method for cable support of stope walls and pillars can be obtained the precise failure mode of the walls and pillars, and the interaction of the support and the rock mass must be investigated.

Jan 1, 1982

By B Hayter, M Carr, K Williams, C Wheeler, W Chen

Current trends into mining iron ore have seen an increase in the exploitation of problematic orebodies that would typically be disregarded. These bulk materials cause problems within all facets of the material handling stream, from remains left in train wagons to transfer chute blockages, which can cause costly downtime to mining operations (Roberts, 1998). These problematic bulk materials are referred to as wet and sticky material (WSM) due to the adhesive and cohesive nature they possess. Their characteristics can be computationally expensive to model. With the development of discrete element modelling (DEM), in conjunction with advancement in computational power over the past decade, it is now more feasible to model WSMs into the DEM technique.This research will couple two different contact models that can represent the characteristics of a WSM. These models include the Simplified Johnson-Kendall-Roberts (SJKR) and the Easo liquid bridging contact models. The SJKR contact model is an expanded form of the classic Hertz model. This model includes the tensile forces that are in the contact zone between two bodies when they are separated, which the Hertz model failed to capture (Johnson, Kendall and Roberts, 1971). The Easo liquid bridging contact model accounts for the capillary effects and surface tension that will form between two bodies, such as that of a WSM (Soulié et al, 2006). Both of these models were coupled to give the best representation of a WSM, which was simulated using MoleculeX™ (Chen and Williams, 2017) as the software platform.Additionally, this research also investigated the adhesion of problematic iron ore samples onto impact plates under dynamic conditions. An experimental set-up consisting of an apron feeder and inclined impact plate was utilised, to gain an understanding of the way the material builds-up and the possible modes of failure that could be experienced. This was undertaken for different wall liner materials, wall liner angles and moisture contents of the iron ore samples. From this, a series of DEM calibration simulations were conducted on the experimental set-up and particle size distributions (PSD) of the iron ore samples. This enabled forming of a database of parameters, which can be scaled for on-site applications in relation to geometry of the plant and PSDs that would represent run-of-mine ores.CITATION:Carr, M, Williams, K, Chen, W, Hayter, B, Roberts, A and Wheeler, C, 2017. The dynamic adhesion of wet and sticky iron ores onto impact plates, in Proceedings Iron Ore 2017, pp 511–518 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

THOSE who dabble in mining are no exception to the general rule that persons who know a little of a subject are apt to think that they know all about it. Some colour may be lent to the belief that anyone may succeed in mining when we hear stories ofsuccessful diggers and others who have accidentally dropped on to something good through no foresight on their part; but we seldom hear the contra account of the far larger number who fail. Those who go more thoroughly into the subject, and take up mining as a profession, know very well that it is not one that can be carried out successfully by rule of thumb, but when they point this out to the public they are credited with trying to make it a closed profession; and outsiders are for ever trying to find out the "trade secrets," at the same time spurning the main one, which is hard study, experience, and the ability to apply their knowledge. The average mining man is not rich. When he amasses a fortune it is generally through speculation rather than professional work, thought no doubt his technical knowledge may have assisted...

Jan 1, 1910

By T Trott, G Lumley

"The mining industry suffers from a shortage of professional and other workers. Research and analysis has demonstrated a close correlation between high performance in productivity, maintenance and safety. There is also a significant correlation between engagement and performance. It is the hypothesis of the authors that mines can use a strategy of establishing themselves as a high-performance mine to attract and retain high caliber professional people: step 1 is to become best practice in equipment performance (productivity, maintenance and safety) step 2 is to brand the mine as æbest practiceÆ by sharing what has been confidential performance and outcome information with the general industry.Previous research has shown that many professional people are attracted by the prospect of a high achieving site because of the learnings and the support for continually doing better. In addition, a link has been established in previous research between productivity and safety. Operators and drivers are attracted to sites which have fewer dangerous people operating or driving. Good management delivers exceptional performance and a work site which high caliber managers and operational personnel people want to work at. The strategy requires commitment and proper execution but it can work. The strategy needs a specific approach and this paper will discuss this. A case study is provided from a mine which over a nine month period increased dragline performance by 15 per cent and reduced stress on the boom by 30 per cent. This mine paid the employees (professional and operational) $25 000/a less than the major mines but the operators and professional people would not leave; in fact, people were happy to be paid less to work there.CITATION:Lumley, G and Trott, T, 2012. Using best practice operations as a strategy for attracting and retaining professional people, in Proceedings International Mine Management 2012, pp 35-52 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 20, 2012

By Hellsten KJ, Butt CRM

Major Francis Hamilton Buchanan coined the term `laterite' (Latin; brick-rock) in 1807 for the red earths used for building blocks in southern India. Although these earths were actually weathered basalts, the term is now applied to weathering profiles developed upon a wide range of bedrocks. The Ni-laterites are a special class within the broad laterite family.

Jan 1, 1996

Major Francis Hamilton Buchanan coined the term `laterite' (Latin; brick-rock) in 1807 for the red earths used for building blocks in southern India. Although these earths were actually weathered basalts, the term is now applied to weathering profiles developed upon a wide range of bedrocks. The Ni-laterites are a special class within the broad laterite family.

Jan 1, 1996

The conclusions reached by den Tex after a study of the fabric of some rocks from Broken Hill have been used to support the epigenetic hypothesis for the origin of the ore, first by Edwards (1959, p. 70) and then by Stillwell (1962, p. 131) in his criticism of Segnit's (1961) views. Den Tex claimed that the petrofabric study provided "independent evidence that the ore, at least in its present form, post-dates all events of a diastrophic nature in the area concerned".Repetition of this claim by Edwards and by Stillwell and the lack of any criticism of den Tex's work for more than three years implies its general acceptance by geologists in Australia. Therefore it appears necessary to examine parts of den Tex's paper in detail to show that his, conclusions are unwarranted. The major weaknesses in his study are that1. the petrofabric study was inadequate to warrant any major conclusions, and2. the petrofabric data allow alternative conclusions.Den Tex made a single visit to the field, collected six carefully selected specimens and presented quartz and· biotitepetrofabric diagrams for two specimens, quartz-diagrams alone for three more and included three diagrams of the orientation of c-axes and fractures in one specimen. It is not reasonable to come to firm conclusions about the origin of such a complex area as Broken Hill on such inadequate data, despite den Tex's claim (p. 87, lines 22 and 23) that "a thorough investigation of the quartz-fabric of the wall rock was undertaken".Den Tex's interpretation of each diagram is open to criticism, and alternative (and to my mind, preferable) interpretations may be made. It is impossible to evaluate den...

Jan 1, 1962

The criterion for assessing the accuracy of coal reserve estimates proposed by Philip and Watson (1982) is criticized.Following Royle (1977), it is suggested that the global estimation variance found by geostatistical methods is more appropriate.This method is applied to coal data from the Bowen Basin. This shows that two factors (the inherent variability of the variable under study and the total number of drill holes) have more influence over the accuracy of the reserve estimate than the form of the drilling pattern. Comparisons between the relative errors for different sized regions demonstrate that the spacing between drill holes is of secondary importance. The dominant factor is the total number of holes.Comparisons between the relative errors show that some variables such as sulphur need a much denser sampling than the others to obtain the same level of precision.

Jan 1, 1983

By I Thomson, L D. Black, R G. Boutilier

The social license to operate (SLO) began as a metaphor for the ability of communities to stop mining projects. Soon people began to speak of levels of social license and the ability of communities to raise costs without completely stopping exploration or mining activities. Today the concept has spread to other industries and is evolving towards becoming a general management perspective on the socio-political rights and responsibilities of the corporation. The business case underpinning the SLO perspective on management is the need to assess and manage socio-political risk. For mining companies, socio-political risk has been steadily rising for several reasons, including the efforts of non-government organisations (NGOs) to pre-empt government policy options; the entry of mining companies into jurisdictions weak in the rule of law; and the weakness of global economic and financial regulation. In this perilous world beyond the comfort zone of effective government, mining companies must build their own socio-political stability by engaging directly with stakeholders to develop a strong SLO. In order to become a practical management perspective, the SLO needs to be measurable, which amounts to measuring the socio-political risks and opportunities presented by stakeholders. We present the results of efforts since 2009 to develop a globally reliable and valid measurement tool at the project and industry levels, validated in studies in Australia, Bolivia, Mexico and the USA. A factor analysis suggested four factors that mine management can address to raise their SLO level. The most chronically neglected factor involves the political right of the corporation to foster more equitable social contracts locally and regionally in both developed and developing countries. We conclude with recommended steps to earn and maintain the social license at the project and industry levels.CITATION:Boutilier, R G, Black, L D and Thomson, I, 2012. From metaphor to management tool - How the social license to operate can stabilise the socio-political environment for business, in Proceedings International Mine Management 2012, pp 227-238 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By Greaves M. C, Amos M. D

A study was made of the instrumentation and technique of atomic absorption spectroscopy developed by Walsh of the Commonwealth Scientific and Industrial Research Organisation (C.S.I.R.O.), Australia.The method was evaluated for the determination of silver in lead sulphide concentrate. The precision of the procedure developed is equal to that of the uncorrected fire assay method and the accuracy is greater.Brief mention is made of the use of this technique for the determination of silver and other elements in ores and concentrator products.INTRODUCTIONThe fire assay method, although accepted on a world-wide basis as the umpire method for the determination of silver in ores and concentrates, is freely recognized as yielding results which are lower than actual due to unavoidable losses.King (1934) investigated the influence of the cupelshape, size and material on silver losses during cupellation. Using 100 mg silver prills he recorded silver losses ranging between l. and 10 per cent under extreme conditions and averaging approximately 2 percent under conditions which might be considered normal. Guerin (1957) made a detailed study, under carefully controlled conditions in a furnace similar to that described by Esdaile (1952), of the effect of temperature on silver losses during cupellation. He concluded that if cupellation were carried out at 840°C., then the amount of lead retained by the silver prill was insignificant and that the silver losses were governed by the equation: Y = 0·055 XO.74where X = the final weight of the silver priIl (mg)and Y = the silver lost (mg)

Jan 1, 1961

The subject which I have chosen for my paper is one that I am sure has occurred to the minds of nearly every mining man on these goldfields at some time or other. I refer to the carrying out of hydraulic mining on a fairly large scale on some ofthe alluvial areas of the West Australian goldfields. There are many, no doubt, who have the question ready at the present moment, "But where is the water coming from? " However, the great difficulties in the way are not due to the want of natural facilities, but due to the fact that sufficiently large areas cannot be leased for this purpose under the present Mining Act. Now, ever since the inception of the West Australian goldfields there has been the old familiar cry when referring to some alluvial gully or flat, "I wish I had a head of water to sluice that ground," but what seems an impossibility at times can be brought to a very great possibility by the use of a little thought and the expenditure of the necessary capital. This is so as regards West Australia with sluicing which, in spite of the its having so many detractors, can be carried out successfully in certain localities if the ordinary facilities on the part of the Govenment are given, and on the other hand the necessary capital is supplied. Alluvial gold areas, I propose now to draw your attention to first of all, the numerous alluvial areas that exist around Coolgardie, Kalgoorlie, Bulong, Kurnalpi and many other centres. Some of these areas have afforded fortunes inthe early days to the alluvial miner, and also afforded a living for years to many diggers' by the use of the dryblowing...

Jan 1, 1901

By Lever R. R

The paper discusses assay methods generally used when prospecting for gold, and also the applicability of various chemical methods, it describes a new paper chromatographic technique.for making fairly rapid semi-quantitative assays for very fine gold. Testing of the method in field work shows that this simple method could have applications in geologic work, in prospecting and in certain routine mine sampling work. It is not yet a method that can be used to detect anomalies in traces of gold dispersed around an orebody, as is general practice in geochemical prospecting.INTRODUCTIONAccording to the English economist Harrod (1958), "the acute shortage of gold in the world-because currency value has not been adjusted in line with the fall in the goods value of the various currencies-has been a familiar fact for some time now". Harrod calculates that a rise in the price of gold to double its present value is necessary to rectify this condition, and that, if this rise were to take place, increase in production and reduction in private hoarding might well bring annual accretion to world stocks from the presentaverage of about $464 million to a figure close to the $2,000 million that would probably eiiminate these shortages.Any increase in the price of gold is bound to lead to a great increase in prospecting at working mines, in abandoned areas and possibly in untouched country. Prospecting, techniques for base metal orebodies have improved greatly in the last thirty years; but methods available to detect gold occurring without accessory metals have not received the same attention. With this in mind a paper chromatographic method of assaying for gold has been developed by Lever (1958). In the field this semi-quantitative method has proved...

Jan 1, 1959

By A Buckley

Many policy issues facing the mining industry and affected communities are at a level of complexity that they can be called ‘wicked’ problems. The term ‘wicked’ in this context is used, not in the sense of iniquity, but rather as social and economic issues highly resistant to resolution. For the resource extraction sector and affected communities there are an array of challenges embedded in the industry’s production and profit paradigm, the remoteness of mineral reserves and affected communities’ expectations of economic benefit and a positive legacy. The mining industry as a whole is dominated by economic, political, legislative and market structures that influence and constrain interactions between mine operations and local communities. For communities, with particular reference to regional Western Australia, intractable problems include the uncertainty of, yet increasing dependence on, a mining economy. Questionable outcomes for local communities include the limited realisation of local employment and business development benefits, and low overall outcomes or low multiplier effects. ‘Wicked’ problems, according to the literature, are best addressed via collaboration. In the mid-west region of WA, with mining and infrastructure construction underway, alliances have formed between mining companies, the major port and rail infrastructure project (Oakajee Port and Rail) and regional and local governance stakeholders. The major impetus for these affiliations is to expedite planning and associated infrastructure development taking into account the lessons from other mineral-led regions. What has resulted is an array of innovative approaches to stubborn problems including planning well in advance of full-scale mining; regionally coordinated procurement; ‘mine ready’ local businesses; and strategic investments in social infrastructure; including community trust funds paid in advance of project delivery. This paper examines these innovative approaches/alliances and assesses their effectiveness in addressing long standing mining/community dilemmas.

Nov 22, 2011