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By E Hollinger, J L. Mauk

Gold-silver mineralised veins at Favona, represent a new low-sulfidation epithermal vein discovery that occurs less than 1 km southeast of the world-class Waihi deposit. The Favona vein is hosted in Late Miocene andesitic lava flows and local dacitic tuffs that are intensely altered to quartz, adularia, chlorite, illite or interstratified illite-smectite (with ten to 70 per cent smectite) and pyrite. Adularia is widespread and envelops the veins, whereas chlorite and illite are mostly restricted to the footwall, and illite-smectite is confined to the hanging wall of the Favona vein. At shallow levels, kaolinite, cristobalite and rare alunite overprint the above minerals. A polymict hydrothermal breccia also occurs above and in the hanging wall of the Favona vein and contains clasts of altered andesite and various quartz vein fragments. Fluid inclusions in quartz veins sampled over a 300 m vertical interval have a homogenisation temperature range of 175¦ to 266¦C and dilute apparent salinities of 220¦C and grading into illite-smectite and local smectite which formed at 2. In contrast, late kaolinite, cristobalite and alunite formed from descending steam-heated acid-sulfate waters. Overall, the Favona and Waihi deposits are interpreted to have formed at similar levels in a single low relief hydrothermal system, with each deposit representing a distinct zone of fluid upflow.

Jan 1, 2002

Predicting Flotation Response from Liberation Information

Sep 13, 2010

By M I. Pownceby, S P. Suthers, V Nunna, G J. Sparrow

Global demand for iron and steel has increased substantially over the past 20 years and there has been a greater focus on developing suitable processing options to treat low-grade hematite-goethite ores containing higher levels of silica and alumina impurities. The processing applicable to reduce the impurity levels in these lower-grade iron ores depends on their mineralogy and a thorough understanding of the process dynamics associated with the separation technology. Different separation technologies used to remove silica and alumina from low-grade iron ores were reviewed. The major concentration methods that may be applied to upgrade lower-grade lump iron ores include magnetic separation, wet and dry heavy media separation, and air-pulsed jigging. The technologies applicable to beneficiating iron ore fines include wet and dry gravity and magnetic separation, flotation, and roasting followed by magnetic separation. It is necessary to investigate the application of separation technologies on a case-by-case basis to select economically viable beneficiation strategies suitable for the particular low-grade iron ore. A commercial flow sheet is expected to involve the implementation of several separation technologies.

Nov 8, 2021

By S Christensen

In August 2001 the Minister for Conservation declined an application by GRD Macraes for an access arrangement to enable work at the Globe Progress Mine near Reefton. In her decision, Ms Lee said:æI have considered whether potential compensation and the proposed safeguards against some of the adverse effects are sufficient to outweigh my concerns as to the loss of conservation values, consistency with the objectives of the Conservation Act, the purposes for which the land is held by the Crown and, to a lesser extent, the North Westland Regional Management Plan. I do not think they are sufficient. To my mind, my concerns as to the consistency with the objectives of the Conservation Act, the purposes for which the land is held and the loss of some conservation values in particular, outweigh any potential compensation and possible mitigation of adverse effects.Æ Commenting on the MinisterÆs decision Guy Salmon of the Ecological Foundation stated that the Minister should have invited the applicant to provide a 10 000 hectare pest-free wildlife sanctuary as part of the æpriceÆ for obtaining that access. However,æfor many people of green persuasion, it has become fashionable to say no every timeàthose who really have the well-being of the environment at heart, will want to look carefully at the bigger picture of environmental restoration needsàThe deciding criterion: the mining company should show that its involvement on conservation land would produce a net conservation gain. That is a criterion that creates the right incentives for win-win-win solutions on conservation land.ÆThis paper considers whether the concept of off site mitigation is one which fits within the current legal regime. Two questions arise:Can such mitigation/compensation be legally considered in access arrangements or required as a condition of resource consents? Is this a realistic option for industry to be pursuing?

Jan 1, 2002

By K Thorpe

Amorphous silica deposits have been identified at Tikitere and Taheke near Rotorua. Two areas at Tikitere have been surface sampled and drilled to establish a resource of amorphous silica in excess of one million tonnes. A pilot plant was established to develop a process to manufacture a high quality super pozzolanic material. This development process took two years before a commercial product was introduced to the construction industry in 1996. The amorphous silica product, marketed as Microsilica 600, is used as a pozzolanic material to produce high quality strong and durable concrete, sprayed tunnel linings, mortars and grouts. Microsilica 600 has been used locally and exported to 11 countries.

Jan 1, 1999

Newmont Waihi Operations is participating in the initiation of a community liaison forum in association with the local district council. The objective is to provide a forum for the free and regular exchange of ideas, concerns and information, and through improved communication seek to achieve a more comprehensive set of solutions to community, operating and closure issues associated with Martha Mine. A similar liaison forum has been operated on two previous occasions during earlier phases of the present mine's operation. This paper deals with the practical aspects of setting up a liaison forum to act as an effective conduit between regulators, mine operators, local businesses and the community. The mechanisms and procedures for identifying community issues and concerns are dealt with. The actions and structures required to ensure effective ongoing community 'buy in' at all levels are discussed. Corporate philosophies are addressed. Specific examples from Martha Mine, Waihi New Zealand will be used to illustrate the paper. This will include a brief explanation of previous and current community issues, Newmont Waihi's operations both at Martha Mine and the proposed Favona underground mine, and the practical issues involved in setting up a liaison forum.

Jan 1, 2003

By L Lorenzen

In this paper, we developed and implemented a fuzzy logic expert system capable of evaluating the degree of sustainability within the context of gold mining operations. The newly introduced approach of evaluating sustainability in the gold mining industry has the merit of sufficiently handling diverse, sustainable, development-related qualitative and quantitative data owing to fuzzy logic technology capabilities in dealing with linguistic syntax. The economic, environmental and social indicator inputs were independently evaluated and then combined with the aid of fuzzy logic to provide an overall sustainability index on a scale of zero to one. A total of 66 independent indicators were identified and applied in our model. The novelty of this work lies in providing a coherent numerical and automated approach in evaluating sustainability in the context of gold mining operations. In addition, the model can aid policy- and decision-makers in arriving at consistent decisions regarding the degree of sustainability on various aspects of gold mining operations. The functionality of this model will be illustrated through several examples.

Jan 1, 2007

By D Readett

The most critical variable in the successful establishment of the Murrin Murrin Heap Leach plant was the effective agglomeration of the Ni laterite ore. This paper describes the test work undertaken to establish the key agglomeration parameters including state of the art testing and analysis procedures. These parameters were then utilised to establish the key design and operational concepts for the world’s first commercial scale Ni laterite heap leach. Following the technical and economic success of the operation, the actual operational data is compared back to the original test work data.

Aug 8, 2011

By Resta S. A

Energy Resources of Australia Ltd - Ranger Mine is located about 255 kilometres east of Darwin in the Alligator Rivers Region of the Northern Territory. The Ranger project is surrounded by Kakadu National Park which is on the UNESCO World Heritage list. . Ranger Mine operates the largest uranium mine and processing plant in Australia. It is designed to produce 3000 tonnes of uranium oxide per year, but presently is producing a little less than one half that figure due to the depressed uranium market. The safety performance of the employees and Ranger as a whole continues to improve. The lost time injuries (LTI) have significantly reduced from 74 in 1985 to five in 1994. The total days lost due to LTIs have gone from 1543 to 14. These significant improvements have reflected directly on workers' compensation premiums in which a four-fold reduction has occurred. It is estimated that the actual monetary saving to the company is about $1.3 million per year and directly reports to the profit of the company. There is also an obvious and significant reduction in the less quantifiable costs such as the suffering of the injured employees and cost to society. The paper will review the various initiatives introduced and assess their effectiveness. Performance improvement is primarily dependent on the commitment, introduction of various initiatives and the subsequent change in workplace culture.

Jan 1, 1994

By J Salaya, J Kwak, L Keeney, S Dehkhoda

In addition to volatile commodity prices influencing decision making, in recent years, social and environmental performance have become important decision drivers within the mining industry. There are increased demands from stakeholders, communities, and governments to ensure that raw materials are mined, processed and refined responsibly. The industry also faces the challenge of better managing its waste, which has led to severe consequences when not done properly. The high commodity prices of the late 90s and early 2000s encouraged larger economies of scale and drove mining companies to extract large volumes of rock for separation and concentration at the downstream processes. Over time, as ore grades dropped, the cost of mining escalated and tailings volumes grew. This arduous process also caused strains on recovery cost and performance. Scarcity of water and energy resources coupled with increased production demands and higher operating costs are putting pressure on companies to find innovative ways to increase mining intensities. Hatch’s value chain optimisation methodologies, specifically Grade Engineering® and early waste rejection of the mine, have been of interest to intensify operational performance and minimise waste generation. Enabling preconcentration of the plant throughput, the methodology has significant potential to improve overall metal production and reduce water and energy intensities, whilst minimising wet tailings. Using representative data from real world mines, this paper reports on a case study that evaluates the impact of preconcentration using sensor-based ore sorting on downstream process improvements as well as energy, water and tailings reduction. Financial and economic viability of this technique is presented for both brownfield and greenfield implementation cases. The results show that business case for preconcentration is best when: the distribution of metal in the run of mine ore is negatively skewed and left tailed; mining costs are low; energy, water and tailings management costs are high; and low cost methods of recovering pay metal from low grade material are available.

Nov 10, 2020

By M Allen

By its nature, the mining industry is energy and emissions intensive. In the future, the world will still require the outputs of mining but the industry will need to adapt to the low emissions economy. Understanding the risks of climate change to a particular site or at a company level is key to managing this transition.CITATION:Allen, M, 2018. Assessment of climate risk in the Australian mining industry, in Proceedings Life-of-Mine 2018, pp 13–16 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By J Hartnett, B Tarrant, A Rayner, D O’Toole, P Davies

Since 2009, the Northern Territory and Australian governments have been working under a national partnership arrangement to inform a rehabilitation plan for the former Rum Jungle uranium mine. Part of the rehabilitation strategy is to backfill a flooded former pit (Pit), which extends down to 100m below the current pit lake surface and was historically partially backfilled with uranium tailings. It is proposed to utilise the remaining pit volume below water level to sub-aqueously store Potentially Acid Forming (PAF-I) waste rock which currently occupies large stockpiles across the site. The rehabilitation design and planning process undertaken to develop a strategy commensurate to project objectives and construction constraints involved the establishment of key constraints derived from the analysis of historic data sources and preliminary design efforts. Tabled strategies were balanced against dependent project tasks and project objectives, especially surrounding minimising disturbance of highly contaminated materials within the Pit. Ideas were developed in conjunction with industry input and review of case histories to develop a remediation solution that is constructible within the project timeframe and constraints.

Jul 1, 2021

By M Wieloch, D Wimpenny, M Chappell

Fibre-reinforced geopolymer concrete (FRGC) contains no Portland cement or steel reinforcement, but instead uses synthetic fibre reinforcement and a geopolymer binder. The use of geopolymer binder in lieu of Portland cement reduces the concrete’s embedded energy (CO2 emissions) whilst the use of synthetic fibres eliminates the issue of reinforcement corrosion, thus enhancing the overall long-term durability of concrete. This paper presents the development of FRGC during a three-year project funded by the Victorian Science Agenda and a consortium of five organisations. The work involved laboratory and field trials and the production of prototype tunnel segments that have been subject to durability and fire testing.FRGC has exceeded the performance of the Portland cement-based control mix in terms of flexural strength, chloride diffusion, water sorptivity and drying shrinkage. Furthermore, the FRGC segments subjected to a simulated hydrocarbon fire test did not exhibit explosive spalling; however, the creep of FRGC was approximately three times that of the steel fibre-reinforced Portland cement-based control mix. The compressive strength and tensile splitting strength of the FRGC were also lower than the control mix. These differences need to be allowed for in the design using FRGC.Prototype bolted tunnel segments of up to 0.8?t mass have been produced from FRGC using standard production techniques and ambient curing. These were successfully produced within a 24-hour production cycle. Cut sections through the segments showed good compaction and even distribution of fibres. The estimated carbon footprint of tunnel segments produced using FRGC is approximately 70 per cent less than that of Portland cement-based segments containing 25 per cent fly ash and steel reinforcement.The results to date indicate that FRGC has the potential to produce a new generation of tunnel segments and, in general, precast concrete products with increased durability and substantially reduced carbon emissions compared to the Portland cement-based concrete with steel reinforcement.A summary of further research carried out by CH2M HILL into a complete elimination of ferrous inserts from segmental concrete tunnel lining is also summarised in this paper. The use of non-ferrous connectors for radial joints in combination with the FRGC technology in the manufacture of tunnel segments will effectively lead to development of a new generation of segmental tunnel lining systems.CITATION:Wimpenny, D, Chappell, M and Wieloch, M, 2014. Fibre-reinforced geopolymer concrete – an innovative material for tunnel segments, in Proceedings 15th Australasian Tunnelling Conference 2014, pp 345–352 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By J D. Illescas, S N. Arnold, D R. Shaw

Ion exchange (IX) as a primary production technique has been applied commercially since the 1950s; its application in the uranium industry continues to be widespread and is utilised to a lesser degree in the gold industry. The majority of ion exchange applications, outside of gold and uranium, have primarily been for secondary metal recovery and impurity removal. Newer developments in the application of ion exchange, as well as changes in regulatory requirements, are bringing about the wider use of ion exchange as a primary production technique not only for high value metals such as uranium, platinum group metals (PGM), refractory metals and rare earths, but also looking at base metals such as nickel and copper. The ability to build lower-cost, safer, less polluting processing plants with smaller footprints is driving a greater interest in IX, with the main competitors remaining solvent extraction and carbon-in-pulp/leach. This paper discusses a number of areas where IX has been applied and its advantages compared with other techniques.CITATION:Shaw, D R, Arnold, S N and Illescas, J D, 2012. Ion exchange in hydrometallurgy - Secondary metal removal or primary production technique?, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 17-22 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By R J. Thompson

In truck-based hauling systems, the mine haul road network is a critical and vital component of the production process. As such, underperformance of a haul road will impact immediately on mine productivity and costs. Operations safety, productivity and equipment longevity are all dependent on well-designed, constructed and maintained haul roads. With the advent of autonomous haul trucks, the haul road itself becomes all the more critical to the success of these type of operations; not only in relation to mine operators requirements for safer and more efficient and predictable haulage systems, but also in response to autonomous truck manufacturers’ requirements for a more predictable and controlled operating environment. This paper presents a brief summary of the state-of-the-art in surface mine road design and then proceeds to examine the design and technological challenges associated providing a safe, predictable and affordable road for autonomous mine haul trucks. The paper serves as a basis for evaluating the contributions that enhancements in road design and management can deliver to autonomous mining operations, an initiative that also has scope for adoption within the operating life of many mines, haul roads and haul trucks.

Nov 22, 2011

By C Simpson

In 2011 the forecasted world demand for iron ore continues to grow, and during this time Australia is looked upon as a reliable supplier of high quality ore. The expansion of the current Australian mines is unlikely to meet the forecast demand. New mines are therefore being actively explored for and when discovered, are quickly being developed into mines in order to meet the world’s hunger for steel.The Solomon Project area is a large new iron ore discovery, located in the central Hamersley Ranges of the Pilbara province in Western Australia. The first Fortescue exploration drill holes commenced on the project in 2007 and to date three billion tonnes (Bt) of iron ore have been defi ned within the project area. Fortescue is fast-tracking the development of the ‘Solomon Stage 1’ project, with rail and mine construction commencing during 2011, and ore to be railed to Fortescue’s existing shipping operations at Port Hedland commencing in 2012. At a designed production rate of 60 Mt/a, the Solomon operation will be one of the biggest production centres of iron ore in the Pilbara.Deposit types include the three dominant mineralisation styles of the Pilbara province, being bedded iron deposits (BID), Channel iron deposits (CID) and detrital iron deposits (DID). All these mineralisation styles are present in large concentrations within the Solomon project area, and when mined will produce two product streams. These are a single product of CID, and a combined product from a blend of BID and DID material.This paper defines the geological characteristics of the Solomon iron deposits as recognised through the exploration and development of this vast resource over the three years since exploration commenced on the project.

Jul 11, 2011

By C Jones

When the Paulsens operation was poised to be placed on care and maintenance, Bill Beament and the rest of the Northern Star Resources (NSR) team capitalised on the opportunity to send the Ashburton region’s only operating gold mine into the record books.A three-stage strategy was devised by NSR to pay off the acquisition and maximise the return from the operation. The first stage was to mine the 55 000 oz mine plan and pay off the cost of the acquisition, then maintain profitable production beyond the seven months and re-establish a mine life. The second stage involved an early commitment to a 220 m long diamond drill drive being placed in the hanging wall of the orebody from which the extensions of the orebody could be further explored, allowing the second stage of the plan to come into effect and extend the mine life by converting Inferred Resources into the mine plan. The third stage of the initial plan was to utilise this drill drive and continue to drill deeper holes beyond the current limit of drilling in the ore zones to extend the orebody and increase the mine’s life.With an ever growing desire to further expand, the young company took on the bold move of establishing its own mining services division. A critical element to the success of this was ensuring that the right people were recruited with the appropriate specialised skill sets.Aligning common goals amongst all NSR team members, from the board and senior management to the work force on site, was critical to integrate the new and driven direction that Paulsens had adopted. It was essential to change the focus and a shift in all employees’ attitudes and values from a mine that was all but down and out, to a site that wanted to be kicking some serious goals.Teaming together a passionate and driven leader with a strong allied workforce was always going to put NSR in the best position possible to make Paulsens the success story that it now is. But without the calculated risks and enthusiastic attitude, the little known mine site in the Pilbara might have remained just that.CITATION:Jones, C, 2014. The Paulsens transformation – a shining light under a northern star, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 191–196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

By M Russ, J Gediga

This paper shows an economic feasible approach to implement greenhouse gas (GHG) reduction measures into the mining and metallurgy industry (MMI). The goal to improve energy consumption is directly linked to the reduction of GHG emissions in the MMI. A baseline scenario of the considered reference system and of the respective reference year has to be designed and analysed. In a second step an analysis of the same operation using the best available technology (BAT) processes is carried out to generate a basis for a benchmark system. The identified gaps will be reported and the potential GHG emission reductions will be put into relation to the investment, running cost and generated carbon credits of the new process technologies to be implemented. This economic feasibility calculation is necessary to realise a cost efficient GHG reduction roadmap decision-making for implementing new technology into the companyÆs business operations. The GHG reduction roadmap is developed using the marginal abatement curve approach.

Jan 1, 2009

By Z-Y Pi, B Zhang, S Wen

"The paper introduces the structure and work processes of outside auger hollow claw tipped mechanical sampler for coal. Twenty sets of claw tipped sampler performance tests show that: The design of inner hollow cylinder-type (?180 mm) can ensure to take a coal sample with nominal top size of 60 mm. Built-in self-cleaning piston pusher ensures no adherence and blocking of the sample. The operation practices show that the mechanical sampler can operate in order for taking coal sample with up to 16 per cent of total moisture. Claw closing design can avoid sample leaking or spilling during the claw lifting and ensure the integrity of primary increment. Ultrasonic positioning device makes the sampler capture the materials no less than 10 cm from the bottom of the wagons, basically meeting the requirement taking full depth of the sample. The precision and bias test indicates that the moisture and ash have no relative bias under the sampling process; the sampling precision is in accordance with the requirement in IS013909.At present, the spiral mechanical sampler is widely used for coal sampling but there are many limitations during application, for example: It is difficult to capture a large size sample, so the size range of a coal sample taken is limited. There is easy adhering or blocking for high moisture coal, which will result in the mixture of different increments, wear of sampler and the difficulties for cleaning and maintenance of sampler. It is difficult to capture the coal sample at lower than 30 cm from the bottom of the wagons, in order to avoid damage of the vehicle. It is possible for coal sample loss and spilling during the sampler lifting, due to the unsealed sampler.For the outside auger hollow claw tipped mechanical sampler designed for solving the above problems, the opening distance of the claw is the opening size of the sampler and makes the size range of the coal sample to be taken wide. During sampling, the two pieces of claws open and the sampler rotates vertically downward to capture an adequate coal sample after reaching the specific point. Then the two pieces of claws close tight automatically to ensure there is no coal leaking or spilling. The inner pusher of the sampler will prevent from the adherence and blocking of the coal sample effectively.CITATION:Zhang, B, Pi, Z-Y and Wen, S, 2012. Outside auger hollow claw tipped mechanical sampler for coal, in Proceedings Sampling 2012, pp 41-44 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 21, 2012

I am wearing two hats today. When the invitations went out to participate in this forum, two were received in the head office of the Department of Lands and Survey - one addressed to the Director-General of Lands and one to the Chairman of the National Parks Authority. It seemed logical that as the department is responsible to the Government for the administration of the National Parks Act 1952, we should respond by providing one speaker to cover both the department's interests and those of the National Parks Authority. I hope, however, that this will not blur the clear distinction which exists in the context of the mineral industry between Crown land on the one hand administered by the department for the statutory Land Settlement Board and national parks and allied reserves on the other hand which are the responsibility of the National Parks Authority.

Jan 1, 1976