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By L Neems

In conjunction with Orica Explosives, Worsley Alumina have managed a program of continuous improvement to their cap rock blasting over the last two years. Blasting conditions are challenging because of the hard and shallow nature of the material. Blasting costs must be controlled and the environmental consideration of noise and dust is critical. Worsley have sought to determine the optimum balance between drilling and blasting costs and fragmentation. As the cap rock has few inherent weaknesses, loader productivity is strongly controlled by the degree of fragmentation from blasting. The optimum blasting solution is also constrained by maintaining airblast levels at the surrounding residences below 115 dBL . The major blast design parameters optimised during the program were stemming type, stemming length, powder factor and blasthole diameter. A series of carefully managed trial blasts were fired during 1997 and 1998 to quantify the effect of these parameters. Fragmentation was digitally measured using OricaÆs Powerseive G technique. Shovel productivity, airblast levels and blasting costs were also quantified. As a result of the project, Worsley now have an increased knowledge of the key parameters driving blast performance, and their consequent impact on downstream processes, the environment and total mining cost.

Jan 1, 1999

By Fountain C. R

In April 1987, Mount Isa Mines Limited (MIM) commissioned an ISASMELT reactor to smelt 15t/h of copper concentrate at the Mount Isa Copper Smelter. This unit was based on the Sirosmelt lance technology and incorporated features proven in the Lead ISASMELT plant which has been operating in the MIM Lead Smelter since 1983. From April 1987 to June 1989, the copper smelting plant treated 167000 tonnes. Concentrate, coal and fluxes are fed continuously to the furnace. Oxygen enriched air is injected through a lance which is submerged in the slag bath. Matte and slag are tapped together through a single taphole into a reverberatory furnace, and from there are treated with normal reverberatory furnace production. Advantages of the process include its ability to eliminate most lead and arsenic in feed, its flexibility with respect to feed composition, sizing and moisture, and the plant's low capital cost. Acceptable refractory life has also been demonstrated. The commissioning of a 70 t/day oxygen plant has rerated the plant from 15t/h to 18t/h while allowing a reduction in fuel usage of one third. A trial using 150 t/day oxygen was carried out in May 1989, and showed that the furnace could treat 48 t/h chalcopyrite concentrate while maintaining a very low fuel requirement. The oxygen trial results have given considerable confidence for plant scale-up. Detailed project evaluation is currently underway for the replacement of the roaster and reverberatory furnaces at Mount Isa with a single 110 t/h ISASMELT reactor.

Jan 1, 1989

By Bin H

East Guangdong tin province overlaps the southmost part of the mesozoic magmatic arcof continental margin type in Southeast China and is dominated by mesozoic syntectic magmatism,which associated to tin mineralization. It is distinguished from Nanling tin province but quite close to NW Bolivian tin province in both tectonic and magmatic relations.Tin deposit's mostly of cassiterite-sulfide, cassiterite-silicate formations are localized along exsocontact zone of granitoid batholith or stock, boundary area of volcanic depression, or, within volcanic edifice. Petrochemistry studies show tin was concentrated as intermediate-acidic magma evolved by fractional crystallization. Xiling tin deposit of vein type related to extrusive... the lava dome was formed at T C 221-301 and at very shellow depth,seems to correspond to type A in classification for Bolivia tin deposits by J.N.Grant. Tashan tin deposit of dissemination type related to hypergene intrusive facies,with mineralization occured in endocontact zone of granite porphyry dykes is considered as porphyry type,which spported by H-0 isotope and gas-liquid inclusion evidences. It formed at T C 250-430, comparable to Bolivia porphyry tin deposits,but at a greater depth 1.3 3.0km.A model for known tin deposits in East Guangdong was worked out. A good prospecting perspective was revealed for the potential type of tin deposit in East Guangdong--subvolcanic porphyry tin deposit.

Jan 1, 1990

By Millett R

In January 1989, Western Mining Corporation (WMC) acquired the Perseverance and Rocky's Reward orebodies and associated infrastructure from the Agnew Mining Company (AMC). AMC had closed the operation in August 1986 and it had been on care and maintenance since that time. To return the operation to full production as quickly as possible it was planned to mine the Rocky's Reward orebody by opencut mining and treat this ore whilst the underground Perseverance workings were rehabilitated. Removal of overburden from Rocky's Reward thus commenced immediately with a target of April 1989 for delivery of the first ore to the concentrator. Extensive rehabilitation and upgrading of the concentrator commenced in late January, and continued in stages for an 18 month period. The first stage consisted of overhauling all existing equipment and completing a crusher upgrade commenced by AMC prior to the mine closure. During this period, it was necessary to recruit a workforce and re-establish all the required support structure. In late April the plant commenced commissioning trials on mullock. The first ore was crushed on the 11th May 1989 and concentrate produced the following day. From May 1989 to June 1990 the plant was producing nickel concentrate whilst further upgrading continued. During this period, the flotation capacity was tripled by installation of a bank of eight Wemco 144L flotation cells in rougher-scavenger duties and two 12 metre by 2 metre diameter columns in cleaning duties. The existing vacuum drum filters were replaced by two Larox PF32 pressure filters, eliminating the need for solar drying and allowing the flash drier to be fed direct from the filters. These, along with a major borefield expansion and further work to the crusher increased the nominal plant capacity from 600,000 to 1,000,000 t/yr. The plant achieved the 1,000,000 t/yr rate in April 1990.

Jan 1, 1991

By R Wilson, S Luke, R Williams, B Freeburn

"In 2010, two McLanahan RSS14×50 scrubber screens were installed at Fortescue Metals Group’s (Fortescue) Christmas Creek site. By 2015, the trommel (screen) section had effectively reached the end of their serviceable life. This was determined by regular measurement of structural components over the previous 18 months that tracked wear life. At the same time, numerous trials and optimisations had taken place on screen panel design and material composition. During 2015, a new set of trommels were designed, manufactured and installed that incorporated many new features: increased open area to facilitate high throughput, improved wear protection for structural members, simplified trommel panels and realigned discharge ports to reduce wear on exit. Numerous other upgrades have taken place on the drive system, feed chutes, liner and weir configurations and park brake, to name a few. This paper will highlight how regular measurement drove design changes and how the site and the original equipment manufacturer (OEM) managed a replacement program that has delivered improved performance.Citation:Wilson, R, Luke, S, Freeburn, B and Williams, R, 2016. Regular Measurement Defines Upgrades on Scrubber Screens, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 285–290 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By H Han, d S. Hapugoda, L Lu

With the recent rapid development of Chinese steel industry, the world iron ore resources of good quality are depleting rapidly. As a result, iron ore deposits of lower quality have been or are being developed to meet the market demand and are becoming increasingly important to iron and steel companies. As concentrates have advantages of high Fe grade and less harmful impurities, they are ideal sweeteners to maintain sinter grade and quality when high proportions of low-grade ores are used in the sinter blends. However, due to their fine nature, addition of concentrates will inevitably increase the proportion of adhering fines and reduced the proportion of nucleus particles of the sinter blends, which can adversely affect the green bed permeability and sintering productivity. In the present study, lab scale sintering tests were carried out under the conditions similar to the sintering process to examine the effect of concentrates on the high temperature sintering characteristics of sinter blends and the structure and strength of the resultant sinter analogues.

Sep 18, 2023

By Tukkimies M

During the late-1980s crawler-mounted crusher units established their position in the aggregates industry. Between 1986 and 1994 about 700 units were delivered to customers all over the world for surface operations, mainly in Scandinavia and central Europe. The crawler-mounted units are popular among smaller crushing operators because they are versatile and easy to move between sites. In large quarries the greatest benefit is obtained by combining a primary crawler-mounted crusher unit with mobile belt conveyors which eliminates the need for costly haulage by dump truck. Savings of up to 40 per cent in production costs prior to secondary crushing have been achieved. Today the environmental aspect in quarrying is assuming ever greater importance. Besides being costly the dump trucks are also the major source of dust and exhaust fumes within a quarry. A complete face crushing system consisting of a crawler-mounted crusher unit and mobile belt conveyors can be electrically driven and can be equipped with dust encapsulation and dust collectors. A mobile crushing unit is not a new idea. From the mid-1950s onwards the mobile and self-propelled units have been built equipped with crawlers, tyres or walking mechanisms, with weights usually of 500-1000 t. Due to their massive size these unit are not mobile in the same way as the today's mobile units. It is not feasible to move them more than a few times a year unlike today's fully mobile units which are often relocated once an hour. This means that the massive units can not continuously follow the production face and their loading always requires a certain amount of haulage. Today the mining industry is facing new challenges. With low mineral prices and high labour costs, increasing productivity is essential for survival. New standards are also being set for the labour safety and the environment. Large research programs have been launched to meet these challenges. However, technology which can partly solve these problems already exist and is only waiting to be introduced into underground applications as well - the mobile crushing unit followed by belt conveying. As in surface operations the elimination of truck haulage also brings considerable savings in operating costs in underground mines and reduces the amount of dust and exhaust gases generated. An additional benefit especially in underground applications is improved safety. In an underground mine most accidents are caused by moving vehicles.

Jan 1, 1995

By A N. Parry, G van Wyk

"Sensor based automatic ore sorting technologies are used in the minerals industries to efficiently remove waste and submarginal grade material from crushed and screened run-of-mine (ROM) ore, producing a coarse (typically >10 mm) upgraded preconcentrate at an early stage in the mineral processing circuit. This avoids additional energy intensive downstream processing of this rejected component of the ROM feed, leading to lower unit operating costs and reduced tailings disposal volumes.Test work on bulk low-grade gold ore stockpile samples from Central Norseman Gold Proprietary Limited has been conducted, indicating high gold recoveries as well as high material rejection rates. A financial model, based on these results, evaluates grade sensitivity and identifies a minimum stockpile grade for adequate financial returns. The base case modelling estimates that the ex-stockpile grade (including the fines bypassed fraction) can be more than doubled through ore sorting and that the project will be highly viable with strong cash flow generation at stockpile grades as low as 0.7 g/t gold. The modelling will enable the company to benchmark ore sorting options against stockpile reclaim and screening operations currently employed. Citation:Parry, A N and van Wyk, G, 2016. Upgrading Low-grade Gold Ore Stockpiles by Preconcentration Using Ore Sorting - an Assessment of the Economic Impact and Viability, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 179–190 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By E T. Baker, J A. Resing, S L. Walker, V Ferrini, F Martinez, R Haymon

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Enumerating active sea floor hydrothermal sites has been a challenge since their discovery almost 40 years ago. High-temperature hydrothermal sites are readily discoverable, primarily by detecting mineral-laden plumes, but working at these sites poses severe environmental and operational difficulties. Low-temperature vent fields, which may represent waning of venting from high-temperature systems, may be more accessible but are more difficult to locate. Over the last decade, however, oxidation-reduction potential (ORP; aka Eh) sensors capable of detecting minute concentrations of reduced hydrothermal chemicals have been successfully used to pinpoint such fields. In this extended abstract, we use ORP anomalies observed during continuous (towed sensor) plume surveys to estimate site frequency along four intermediate- to fast-spreading ridge sections. From these data, we estimate site frequencies between five and 16/100 km for these ridge sections. Previous camera surveys on the fast-spreading East Pacific Rise support these frequencies. These rates are much greater than the frequency of ~0.5–5/100 km, generally increasing with spreading rate, derived from well-surveyed ridge sections in the InterRidge database (InterRidge, 2014). The higher frequencies arise because ORP sensors are able to distinguish between sites as close as ~1 km and identify sites with negligible or no optical plume signal.CITATION:Baker, E T, Resing, J A, Martinez, F, Haymon, R, Walker, S L and Ferrini, V, 2015. How leaky are oceanic ridge axes? A new assessment of the spatial density of submarine hydrothermal discharge, in Proceedings PACRIM 2015 Congress, pp 3–8 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Caress ME, Knight MD

The eruption 75,000 y ago of the Younger Toba Tuff ignimbrite and associated ash-fall ranks as the greatest known volcanic event of the past million years. The ignimbrite is known to cover 21,000 km2 (it may extend farther under alluvium of the coastal plain) and forms a low-angle depositional shield centered on the Lake Toba caldera. The ignimbrite is largely nonwelded and shows systematic outward decreases in lithic and crystal contents and clast sizes. Coarse lithic lag breccias that occur at places 85 km apart point to two or more vents on a fissure having this length. The extensive associated ash-fall traceable as far as Malaysia and India is evidently a co-ignimbrite ash but could have a phreatomag-matic component. The Lake Toba caldera measures95 x 35 km and is >1 kn deep. It is not a single caldera but comprises several contiguous depressions and grabens diversified by two re-surgent domes. Earlier parts of the caldera are related to at least two earlier ignimbrites including the Older Toba Tuff dated by Chesner at 0.5 Ma. The caldera is elongated parallel to, and is only 25 km from, the great Sumatra strike-slip fault, and it can be considered almost certain that the caldera is in part a kind of pull-apart structure. The ignimbrites are very crystal-rich. There is no reason to think basaltic magma was involved in their emplacement. Together with ash-falls they have a total volume of several thousand cubic kilometers. They can be categorized as originating from partially crystallized granitic magmas that erupted because tectonic pull-apart occurred several times across the pluton. Small rhyolitic lava domes on fault-lines comprise the youngest volcanic products.

Jan 1, 1990

As an Inspector of Mines in Queensland, my main responsibilities include the enforcement of the Mining Act 1968 - 1986, the Mines Regulation Act 1964 - 1983 and the Metalliferous Mining regulations 1985 to promote the safe and responsible exploitation of the States' mineral wealth. An important adjunct to this task is the offering of an advisory service to the mining industry. However, in the pursuit of my duties to this regard, I have sadly observed in some cases, numerous wrong doings and negative activities by miners which have led to their ultimate demise, not to mention that of others. Despite what I consider corrective advice, I have witnessed, again in some cases, disregard and blind pursuit for the wrong end. This then is a novel approach to get the message home in the form of a light hearted cartoon presentation relating the saga of an average Aussie battler entering the mining game unprepared, making the wrong decisions due to his own ignorance and the cleverness of others, leading finally to his and possibly others' downfall. It is not intended to insult any particular profession or group of individuals and only endeavours to impart to readers and listeners, the message of being prepared and alert when entering the gold mining industry. Even though the presentation focuses on the woes of a rookie alluvial gold miner, a similar analogy could be drawn with his hard rock counterpart since the basic issues that I have attempted to address are common. By no means is there a saga complete because there are many more traps a miner can inadvertently fall into and only time has prevented me from referencing them.

Jan 1, 1989

By S O’Connell, M Scholz, A Robertson, M L. Bloss

The value created in any mining operation is a function of the mine plan. The quality of this plan is dependent on the strategies employed during definition drilling, resource estimation and mine planning. This paper presents opportunities to improve the value of an operation through better strategic management of these core activities. Case studies undertaken recently at Olympic Dam are presented to support the conclusions presented in the paper.CITATION:Bloss, M L, O’Connell, S, Robertson, A and Scholz, M, 2016. Do we maximise the value of our operations through our definition drilling, resource estimation and mine planning strategies? In Proceedings International Mine Management Conference, pp 9-20 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 22, 2016

By D Pearce

The 15-year long debate between the industry, Government and Aboriginal people about the rights and wrongs of Land Rights, the right of Aboriginal people to control development on their land and the relationship between the parties, has been long and often bitter. It has so far been a war of words and often the truth has been the first casualty. This paper looks at the debate and presents the perspective of Aboriginal people, as well as looking at how the industry and Aboriginal people can work together for everyone's benefit. It addresses such matters as: ò why Aboriginal people believe they have the right to control development on their land; ò the perception that Aboriginal people are anti-development; ò the perception that Aboriginal land is 'locked-up'; and ò how companies can negotiate with Aboriginal people.

Jan 1, 1994

By K Nesbitt

Draw control at Premier Mine is considered important to avoid conditions of isolated draw, which results in early waste ingress, compaction of the kimberlite ore and loss of ore reserves. The Premier Mine kimberlite pipe is unique in that the pipe is cut at a depth of 400 metres below surface by a 75 metre thick gabbro sill. All cave mining at Premier is below the sill and failure to exercise good draw control could cause early ingress of gabbro waste. Gabbro causes problems in the diamond recovery plant and the amount of gabbro sent to the plant needs to be closely monitored. Fortunately coarse gabbro fragments are easy to recognise in drawpoints. It was anticipated that only 85 per cent of available ore would be drawn from the blocks immediately overlain by the gabbro sill before excessive gabbro waste forced the closure of drawpoints. Data on tons drawn per drawpoint and loaded per LHD as well as the tons tipped per pass is gathered by the vehicle monitoring and control (VMAC) system and information recorded by the load-haul-dump (LHD) drivers. Draw control staff monitor drawpoints on a shift basis and record the occurrence, type and height of hang-ups. Information pertaining to the status of the drawpoint in terms of support, waste and availability is also recorded. A database has been compiled that has been used to analyse the overall pattern of draw control, the frequency of occurrence of different types of hang-ups, secondary blasting efficiencies and drawpoint and LHD productivity. The gabbro sill has provided a unique marker horizon that has allowed the arrival of rock from a level 100 metres above the production level to be recognised. Data shows that ore migrates extensively towards groups of drawpoints that are heavily drawn with many drawpoints more than 100 per cent drawn before gabbro waste was recognised. This indicates that an accurate mixing algorithm is essential for good draw control. Data on tons drawn, drawpoint availability, productivity and the occurrence of various types of hang-ups has allowed better control of the mining operation and provided data for planning future caves. In the BA5 mining block a drawpoint spacing of 22 metres, horizontally across the major apex, has still allowed drawpoints to be pulled to waste with no loss of ore. In the BB1E mining block the drawpoint spacing has been increased to 23 metres and no problems have been experienced to-date. Future initiatives centre on improving the data gathering integrity of the vehicle monitoring and control system and a linear programme that will optimise draw control and productivity.

Jan 1, 2000

By Dunlop JSF

A description of general mining proced- ures and tyre maintenance practice is given with particular reference to tyre mainten- ance facilities and record keeping at Groote Eylandt. Experience with tyre wear on Wabco 85C rear dump trucks is then outlined, concen- trating on wheel camber, wheel alignment, truck speed, tyre pressure, loading and haul road design. T T.1TUnilhTPTTnAT The Groote Eylandt Mining Company Pty. Limited mines and beneficiates sedimentary manganese ores from a series of orebodies occurring in the western part of the island. The island is one of a group on the western side of the Gulf of Carpentaria, about 50 kilometres from the Arnhem Land coast and about 650 kilometres from Darwin. Whilst capacity of the mine is presently 2.3 mil- lion tonnes of product per annum, current production has been reduced to just more than half this figure, due to a general mar- ket recession.

Jan 1, 1982

By T Christopher

The Campamento Au/Ag deposit, discovered by Linear Gold in 2004, is located in Chiapas State, southern Mexico. The deposit is hosted by a sequence of Pleistocene-Pliocene andesitic volcanic rocks that have been intruded by a feldspar-phyric porphyry complex. Measured and indicated resources are 852 000 oz Au and 3.46 million ounces Ag with inferred resources of 374 000 ounces Au and 920 000 oz Ag. Resources were estimated at a 1.0 g/t Au equivalent cut-off. This is an ABSTRACT only. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By N Redwood, N Fowkes, A Bassom, S Durkin

"It is well known that from time-to-time a vehicle will interact with a bund or windrow and often the barrier is insufficient to safely arrest that vehicle. The result of such an incident is often catastrophic. Regulations around the requirement for edge protection near pit edges vary between jurisdictions. Generally in Australia regulations tend to be around placing the responsibility on the mine operator to provide ‘adequate’ or ‘appropriate’ edge protection. Guidelines often place a minimum height of bund at between half and two-thirds the diameter of the largest tyre on-site.Safescape has identified the opportunity to improve safety in open pit edge protection and is currently developing the Edge Protector (EP) product. The EP is designed to create a vertical front face to a conventional broken rock safety bund. The fundamental premise of the product is that by creating a vertical front face to the bund, trucks cannot easily drive up over the bund and instead have to push through the rock to get to the other side.In addition to providing a safer system for arresting vehicles, the vertical front face also means that extra space is made available in the haul road. This can either be used to facilitate larger trucks or when designing a new mine, with an increase in overall pit slope.This paper outlines the research and development of a new edge protection product. Discussion will include project objectives, economic incentive for mines to apply the system, mathematical analysis of the truck/bund interaction and physical testing of the product.Citation:Durkin, S, Fowkes, N, Redwood, N and Bassom, A, 2016. Innovative Approach to Open Pit Edge Protection, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 138–149 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By T Craske, J Sykes, T C. McCuaig, M Jessell, A Trench

The prevalent strategic approach in the mining industry is one of planning. However, it is widely recognised that planning does not work in complex and uncertain situations (Mintzberg, 1994), such as those associated with ‘above ground’ non-technical orebody complexity (Trench, Packey and Sykes, 2014). Mintzberg, Ahlstrand and Lampel (2009) suggest the focus instead should be on strategic ‘thinking and doing’ and using the many ways to think about strategy to make sense of complex, uncertain, and unique situations. They therefore place great value in cognitive flexibility. Scenarios development utilizes several different thinking styles and thus assists with this type of flexible strategic thinking (Figure 1). The ‘Centre for Exploration Targeting (CET) Scenarios’ were developed with the ‘Oxford Scenario Planning Approach’ (OSPA) (Ramírez and Wilkinson, 2016). The OSPA aims more to improve the thinking skills of decision makers, rather than forecasting per se (Wack, 1985a, 1985b). As such, this paper focuses less on the content of the scenarios and instead on the practical value of scenarios in strategizing. CITATION: Sykes, J, Trench, A, McCuaig, T C, Jessell, M and Craske, T, 2018. Strategic thinking about long-term ‘above ground’ orebody complexity using scenarios, in Proceedings Complex Orebodies Conference 2018, pp 60–64 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

The AusIMM came into being to foster the spread of professional knowledge within its client industry. It has evolved along with the Australian mining industry for more than a century. If the AusIMM is to become the world's premier mining professional body (whether by design, or by default), then draw up a strategic plan to get there. Define your strengths and market them Define the priority areas for professional competence which we most need, Target the groups within Australia who can produce the people, Create an industry peer group to speed technology transfer.

Jan 1, 1994

Eleven years ago I addressed delegates to the Whyalla Meeting of this Institute on the subjects 'Oil in Australia?' -- a title which was followed by a large question mark.My purpose at that time, which was before Rough Range, was to interest members of this Institute in the possibility of oil in this country because I considered that exploration for mineralwealth was our concern.I doubt if I made much impression.but.I recall that the Chairman at that Meeting, Mr Ian McLennan, asked me pointedly to name the areas I-would select and I nominated the Northwest of Western Australia,'Gippsland and the Roma District

Jan 1, 1962