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By Elford H. S

Australia has many potentially important tin deposits, particularly on the eastern shore of the continent and in Tasmania. A number of these have been worked on a meagre scale, while some of them, because of metallurgical, transport, and other difficulties, have not as yet been developed.Believing that the full development of the tin fields of the Commonwealth of Australia is in part dependent upon the adoption of the most efficient methods of milling and smelting, the Development and Migration Oommission arranged for the first-mentioned author to visit the mining fields of Cornwall, one of the oldest tin-producing districts of the world, and prepare a report for the information of the Commission.This paper, now presented to the Australasian Institute of Mining and Metallurgy with the hope that it will assist the full development of tin mining in Australia, is the joint work of both authors.For over two thousand years tin has been produced from the Cornish mines. Even the ancient Greek historians made mention of tin mining in Cornwall, and it is probable that during the earliest periods the mining was alluvial. As early as 1602 a stamp battery working in Cornwall was described, and in 1671 calcination and buddling was a recognised scheme of treating pyritic ore. In the first half of the 16th century the output of tin from Cornwall was 700 tons per annum, and, from then on, production increased to the maximum in 1914 of 6500 tons. At present (Oct., 1929) the Cambourne-Redruth area produces over 95% of the Cornish tin output. This area includes such mines as the South Crofty, East Pool, Dolcoath, Parkanchy, Polhigey, and Wheal Kitty. The remaining 5% is largely supplied by the Levant and Geevor mines at Pendeen, St. Just area, near Land's End.

Jan 1, 1930

By N Davies, M J. Coward, P L. Hissey

Mount Isa Mines has four mining operations in Mt Isa with the X41 and Enterprise Mines producing copper and the Lead Mine and George Fisher producing lead zinc and silver. Each stream contributes ore to their respective concentrator at a feed rate and therefore metal ratio set out by the monthly schedule. Mine Planning and scheduling lead to a sales and operating plan (S&OP) and revenue projections which ultimately derives actual revenue /tonne and therefore cost/tonne. At Mount Isa, both the copper and lead/zinc streams produce ore from relatively new operations to be blended with material from more mature operations. It is critical to accurately predict the metal contribution from each operation in order to gauge the relative performance of each mine. Development mining ore contributions are estimated and reconciled, as are stope and bench sources. Performance is continually measured and assessed during extraction and grade adjustments are made to account for underbreak, overbreak and design modifications. It is critical to not understate or overstate the contribution from one operation relative to the other as this can produce a false picture of operational performance. Identifying process improvements are key to improving the business overall. Ore from the lead stream passes 17 measurement stations and two midstream reconciliation points before delivery to the heavy media plant (HMP), where the metallurgical circuit begins. From this point two concentrates are produced. A zinc concentrate for treatment off site and a lead concentrate for further on site processing. The lead smelter takes 100 per cent of Isa concentrates as well as a contribution from BHP-BillitonÆs Cannington Mine.

Jan 1, 2002

By M D. Kuruppu

Fleet operational effectiveness is fundamental to any operation, becoming highly topical in mines experiencing less than optimal output from their fleets. It is an all encompassing aim to identify those factors that could be improved within production and suggesting solutions in order to optimise the existing fleet and obtain the highest return on capital expenditure. The fleet operational effectiveness of a large open pit truck and shovel operation in Western Australia was examined and a study was undertaken allowing identification of areas falling below target. The annualised hours and production downtimes were investigated to quantify the potential gains of improvements in these areas. The project aimed to maximise direct working hours through determination of the main issues hindering performance. External and internal factors were considered and a continuous improvement program (CIP) was developed. The CIP aimed at internal site-based improvement teams to identify and implement solutions for improvement on a day-to-day basis. Strategies were then identified for the implementation of the proposed changes.

Jan 1, 2003

In 1969, Queensland Mines Limited obtained two large Prospecting Authorities in Arnhem Land, Northern Territory, Australia. The Nabarlek uranium deposit containing some 12 000 t of U308 was discovered on one of these in June 1970. Mining and stockpiling of this deposit were completed in 1979 and processing to yellowcake, which commenced in June 1980, is expected to occupy an 8-10 year period. The continuation of exploration, essential for the company to become a longer- term producer, was inhibited in 1972 by a Federal Government "freeze" on exploration in Aboriginal Reserves in the Northern Territory. Subsequently, the procedure for explorers to gain access to exploration areas in Aboriginal land was radically changed by the proclamation of the Aboriginal Land Rights (Northern Territory) Act 1976. As a result of this Act and the associated administrative policies adopted by Governments, Queensland Mines Limited has not yet regained access to the exploration areas it formally held in the early 1970's.

Jan 1, 1986

The GDR has extensive lignite deposits at its disposal, which formed the basis for the development of an independent energy source after 1945 and which will retain their significance well beyond the year 2000 (see fig. 1). In 1946 lignite output was about 110 x 106 t. In 1985 312x 106 t was produced and in 1988 the planned output will be ca. 315 x 106 t. Thus, the domestic produc- tion of lignite covers ca. 75% of the GDR's primary energy requirements. More than 80% of the electrical energy is gener- ated by the use of lignite and about 12% by nuclear energy. In addition to this, about 18 x 106 t/a mineral oil and about 6 x 109, m3/a natural gas are imported, predominantly from the Soviet Union. The lignite deposits of the GDR are of Tertiary origin and are recovered exclusively by opencast mining. There are two large regions (fig. 2): - in the region east of the river Elbe (Cottbus/Senftenberg- "Niederlausitz") and - in the region west of the river Elbe (Halle/Leip- zig/Magdeburg). These deposits differ in geological age and conditions of depo- sition, consequently there are differences in their chemical and physical composition and, thus, in their uses. The younger Mio- cene coals of the main region in the East of the river Elbe belong to the epirogenetic type and have a low content of ash and sul- phur. Among other things, they are suitable for the production of brown coal high-temperature coke (Lauchhammer and Schwarze Pumpe). The older Oligocene coals of the Halle/Leip- zig region are bitumenous in certain areas. Therefore, they form the basis for production in low-temperature carbonizing and chemical plants. In the Halle-Magdeburg region, where the lig- nite is in contact with the underlying Zechstein subdivision, so- called "salt coals" are found.

Jan 1, 1989

A cry that is often heard from front-line employees, particularly as a mine grows or circumstances change is "We used to be one big team but now they have set up teams for different functions - we don't know what's going on and we don't share resources any more. We used to just get in and do what had to be done, now we can't.". It usually occurs after management decides that, with the increasing mine complexity, functions and accountabilities of a manageable size need to be identified and defined for individuals and teams to facilitate optimum performance. However, as the statement indicates, these changes have often not delivered all the intended benefits. This paper will explore the reasons why the full benefits have not been realised and will identify actions which can be taken to improve the likelihood of optimal outcomes.

Jan 1, 1998

By Bhattacherjee A, Makesh S

Mechanised sub-level stoping is one of the most widely accepted stoping practices followed in base metal mines in India. As a general practice, blast-scheduling of rings in these stopes is done either heuristically or randomly which leads to a high fluctuation in ore grade when drawn and delivered to the mill. In this paper, dynamic programming has been investigated as an optimisation technique for optimal blast-scheduling of rings. A microcomputer based dynamic programming algorithm has been developed in C language which runs under the UNIX environment. A case study based on Indian mine data is presented to demonstrate the application of the dynamic programming concept and use of the developed software. It is concluded that dynamic programming can be used as a production planning tool in Indian mines practicing sub-level stoping and following heuristic/random approaches for blast-scheduling of rings.

Jan 1, 1995

The last decade has seen a very rapid development in TBM tunnelling. Some trends are purely technical or economical and others relate more to preferences of different interests. Power levels have more than doubled and thrust levels too. Shield machines are developed to be able to handle harder rock and the open TBMs are made more feasible for `difficult' rock. What is right and what is wrong is more a matter of opinion, but one thing is certain: TBMs now are a useful tool and no longer an experimental work-shop for the enthusiasts.This paper highlights some recent developments and indicates some probable future ones. A few features that have increased the open TBMs' ability to cope with ever harder rock and also to overcome problems with poor rock are discussed in detail, using the Atlas Copco JARVA Mk 27 -the most powerful TBM built so far - as a reference.

Jan 1, 1993

In the years prior to the outbreak of war in 1939 Australia's production of copper had declined from a peak of about 80,000 tons in 1911-1915 to approximately 25,000 tons in 1939. This production met the need of the slowly growing national requirement and gave an excess for export. However, with the intensification of the war effort in 1942 due to the imminence of a Japanese invasion of this country, or at least a blockade of the sea lanes, it became necessary to expand production of armaments, and consequently the demand for copper increased beyond the capacity of the industry. Importation of copper to Australia during the period 1940-1944 was 131,000 tons.When exploration of the Mount Isa orebody was first being carried out in 1928, No. ID diamond drill disclosed the presence of some copper ore lying outside the limits of the Black Star orebody2, but it was not until 1941-1942 that the development of No. 7 level in the Black Star orebody enabled the existence of a lode of copper ore of economic grade to be established. At the request of the Commonwealth Government of the day a programme of development for copper production was undertaken whilst lead smelting was continued as before the war.A series of flotation tests on up to 1,500 tons of ore at a time, was undertaken and the concentrate so obtained was stockpiled. These tests were conducted, using one section of the lead mill, and demonstrated that a concentrate grade of 22-23% Cu with a recovery of 80-85% might be expected.These recovery figures were afterwards much improved, and 93-95%was obtained before the close of smelting in 1946.

Jan 1, 1953

By Misk A

Several logging methods are presently available to the oil industry for the evaluation of formation porosity: the Sonic and Neutron logs are already widely used, the Gamma-Ganmia log is being progressively introduced. The readings of these instruments are primarily a function of the rack-porosity, hence the general term of "porosity tools". Apart from porosity, however, other variables such as type of fluid in the pores, nature of matrix and degree of shaliness have an important influence.The response of each device is a different function of such parameters: therefore, a cci bination of porosity tools can lead to information on these variables in addition to the evaluation of effective porosity.For example, the presence of gas; rather than water or oil, in a formation which is not deeply invaded, will tend to give Neutron derived porosity values which are too 'low; on the other hand, the Sonic derived porosity: value will be too high in such- a case. For the same porosity, the Sonic gives a longer transit time in sandstone than limestone, whereas in the low porosity range, the Neutron will read more counts per second in a sandstone than in a limestone of the same porosity. The presence of shale also affects the readings of the various porosity tools in different ways so that the combination of two or more methods may lead, in some cases; to an evaluation of both the-effective porosity and the shale, content.In conclusion, it may be said that the various porosity tools pre-sently available, are, to a large extent, complementary, and that in many problems the use of two porosity tools, instead of one, is very likely to bring valuable additional information.

Jan 1, 1962

By V S. Svinin, V V. Rybin, V A. Maltsev

In large-scale mining, large-sized intermediate pillars, or block-pillars, are generated on the horizon or between closely located mines. These pillars are mined under high rock pressure that results from the stress concentration zones superposition from closely located working excavations. This problem becomes much more complicated if high tectonic stresses occur in the rock mass inducing a rock-burst risk situation. Mining experience gained in mining seven block-pillars at three Khibiny mines in Russia under the geomechanical situation like that described aboveÆ is discussed in detail. It has been shown how safe mine of block-pillars depends on their width, location relative to significant geological failures and uncaved rocks of the hanging wall, the order of pillar recovery, and application of special measures for rock mass stress relieving. Basing on the analysis of the mining experience and special scientific researches, the basic principles are worked-out for safe block-pillar mining under rock-burst prone conditions.

Jan 1, 2000

In presenting the paper, Mr. Davey quoted subsequent work which yielded k, at miscibility gap composition, of about 50.We can confirm the authors' findings for k j 300 for nearly pure tin to k 2 about 50 (average 47) from our own experience and from repeat experiments on materials described by the authors, at 1150°C.During laboratory-scale trials we also found confirmation of the authors' view that it is more difficult to reach equilibrium from the high-iron (in slag) side than from the low-iron (high-tin) side. Working from the high-iron side tends to yield results that point to a high k, leading to optimistic values of iron/tin ratio in final slags. In practice the smelting of a tin concentrate, unless it is exceptionally low in tin and high in iron, must yield initially a tin-rich slag and therefore equilibrium can only be reached from the "tinny" side.

Jan 1, 1967

Christmas Island contains large deposits of phosphate minerals varying from high-grade calcium-phosphate (apatite) to lower grade iron and'aluminium phosphate (crandallite/millisite). The surface material is dominantly C-grade (Fe/Al) phosphate profiling into B-grade, a variable mixture of C- and A-grade ores, before reaching the high A-grade phosphate (apatite) which overlies a limestone Karrenfeld Base formation. A-grade ore is the basic phosphate used for the manufacture of superphosphate and phosphoric acid, whilst B-grade contains amounts of iron and aluminium which are unacceptable for these acidulation processes. Research into methods of separating the finer iron and aluminium phosphates from the coarser calcium phosphates has led to the development of wash-screen processes enabling recovery of 50 to 60%, as A-grade phosphate. Developmental stages included laboratory investigations, mineralogical studies, pilot tests leading the initial 20 tph prototype production unit and the current 100 tph production wash/screen plant, commissioned early in 1970 at Christmas Island.

Jan 1, 1971

By R Huntley, D Sims

Pajingo gold mine produces over 240 000 oz Au per year from underground mining using longitudinal bench stoping methods with a 15 m sublevel interval. Average mine head grade is around 12 g/t Au, contained within quartz veins between 0.5 to 16 m wide. The veins dip steeply (>60¦) and exhibit strike variations which lead to many curved and meandering drive/stope geometries. Unplanned dilution at Pajingo is predominantly controlled by fault planes that subparallel the vein and commonly lead to slabbing failure from the stope walls. Initial efforts at determining maximum spans were based on using the Stability Graph method of stope stability. However the method had a number of shortcomings that did not address mine site observations, including previous mining, interaction of different joint sets and the presence of discrete shears which resulted in poor prediction of stability. A method was developed to rate the risk of dilution for a stope based on observations made in the ore drives. The method utilises profile mapping of the ore drive, structural features observed and the orebody itself, on 10 m spaced sections along the ore drive. A matrix of factors determines the dilution risk for stoping at the time of mapping and the rating is transferred to longsection plots in the office. The dilution risk rating is used to determine the position and density of cable bolt support aimed at lessening the risk, and can be used to review blasthole designs prior to finalisation. The method has been used for more than two years and has proven to be a good indicator of potential unplanned dilution (ie waste outside of ring design). A recent review of the dilution risk mapping process has indicated it is assisting in reducing the impact of dilution at the operation and has the scope to be utilised further in the design process.

Jan 1, 2002

Individual specimens of sphalerite from the Broken Hill lode vary considerably in manganese and iron contents, even within the same orebody, so that study of the overall variation of manganese and iron content of the sphalerite calls for the analysis of a large number of specimens. This difficulty has been overcome by analysing a series of recleaned zinc concentrate products, prepared from stope samples and their equivalents, from most of the developed sections of the lode. The analyses reveal that during the formation of the sphalerite the concentrations of iron, manganese and zinc in the mineralizing solutions varied independently of one another from place to place in the forming orebodies, and also in time.The overall pattern of variation of the iron and manganese contents of the sphalerite in the several orebodies of the lode bears a general resemblance to the overall pattern of distribution shown by several other elements, notably, cadmium, lead, bismuth and arsenic. The iron content of the sphalerite indicates that it was formed at a temperature of 6000 C. or higher, but the variation in its iron and manganese contents demonstrates that Kullerud's method for determining the temperature of formation of sphalerite from its iron content must be used with caution if only single specimens of sphalerite are available.INTRODUCTIONThe four chemical analyses available of specimens of practically pure sphalerite from the Broken Hill lode (Table 1) reveal that the manganese content of the sphalerite varies considerably, and that there is a significant variation in its iron content. The variations revealed between individual specimens within the same orebody in the same mine suggest that specimen material is unsatisfactory as a basis for studying the overall manganese and iron contents of Broken Hill sphalerite, unless a great number of specimensis analysed.

Jan 1, 1956

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 J Q. Shi, M Karakus, Y Liu

Predicting the spatial distribution of rock mass properties in cave mining is a critical challenge. In this study, we introduce a novel machine learning-based model to advance our comprehension of rock behaviour. This model specifically focuses on the spatial distribution of rock mass and mechanical properties, a crucial aspect of our understanding of rock mechanics. Our model is inspired by the recognition that neighbouring information serves as crucial prior knowledge for predicting the spatial distribution of these properties, wherein closer neighbours are likely to exhibit similar characteristics. To effectively capture and model these neighbour relationships, we design a neural network-based model to map the spatial locations within the data set into a new highdimensional space. Within this transformed space, we utilise Euclidean distance to identify N neighbours. Leveraging these neighbours, we introduce a straightforward yet highly effective approach—label propagation—to construct a graph that illustrates neighbour relationships. This graph not only facilitates the prediction of the spatial distribution of rock mass properties but also offers a measure of uncertainty for these predictions. We validate the proposed method using a real rock data set and showcase its efficacy in capturing intricate relationships and distributions within rock properties, enabling precise predictions across diverse spatial scales. Our results underscore the potential of machine learning-based approaches to revolutionise the field of rock mechanics, providing valuable insights applicable to geotechnical engineering, mining, and other sectors where an accurate understanding of rock properties is paramount. This model has direct practical implications, offering a new tool for geotechnical engineers and mining professionals to enhance their understanding and prediction of rock properties, thereby improving safety and efficiency in their operations.

Sep 1, 2024

By L E. Setiawan

The mining and milling groups at Batu Hijau are tasked with increasing SAG mill throughput by approximately ten per cent. Avenues used for this process are blasting and crushing optimisation, ore blending and predicting SAG mill throughput in relation to the geological model. This is in line with traditional æMine to MillÆ studies. At Batu Hijau, mill and mine sequencing cannot readily be configured to perform the surveys traditionally required by a æMine to MillÆ study while meeting the daily production target of 140 000 tonnes per day and processing from varying ore types in one pit. A program called BOCCOST (blasting optimisation crushing conveying optimising SAG throughput) has been implemented to capture approximately 200 variables from blasting, mining and milling operations and assign them to a common point in space in the geological model in real time. Interpretive analysis of data from BOCCOST is used to model relationships between the 200 variables to determine which and how these factors affect SAG throughput. Once these relationships are determined, the blasting, ore blending and crushing process can be optimised to generate a product that maximises mill throughput. The relationships modelled from BOCCOST are also used to generate a SAG mill throughput estimator, which can be coded into the production block model. The block model can be reconciled with the geological block model for correlation by geological domain. Once this relationship is established, SAG mill throughput domains can then be established for predicting SAG mill throughput. This SAG mill throughput estimator is then used in conjunction with revenue calculations to determine an ore cut-off, which combines these two elements to maximise metal production.

Jan 1, 2002

By R Harding, T Hunt

For the past 120 years, Portland cement manufacture has been undertaken on the shores of the Whangarei Harbour in northern New Zealand. Through a serendipitous conjunction of geo-chemistry, the argillaceous marl found on Limestone Island in the harbour and Tikorangi Hill provides a perfect mix of the various elements required for strong and durable cement. Golden Bay Cement, and its predecessors, have been the guardians and managers of the use of these minerals. As the demands of the concrete industry have increased, so have the needs of the manufacturing process. Careful mapping of the resource at both Portland and Wilsonville Quarries has been undertaken. This has allowed the Company to change the Quarry operation from a purely volume basis to one of selection and blending of constituent minerals. Within the manufacturing process, change has also been introduced. Analytical techniques, using x-ray fluorescence spectrometry, microscopy and the application of modem data collation, has allowed fine tuning of the process. The Company now produces an increasing diverse range of products for both the domestic New Zealand market and exports to various South Pacific countries. This paper discusses the processing of limestone and æcement rockÆ into cement clinker, an intermediate synthetic mineral ground into cement. It examines control and blending regimes, and some methods used in determining process efficiency. An important technique ærediscoveredÆ has been the application of microscopy to clinker.  Examination of the major silicate minerals enables interpretation of the kiln processing and feedback to process operators. It also enables a prediction of indicated performance when ground into cement. Examples this paper give an insight into the use of minerals from Northland in some of the more important construction projects in modem New Zealand.

Jan 1, 1999

Anyone who has driven backwards using only their rear view mirrors knows how difficult it is to avoid spinning the steering wheel the wrong way. So why run your mine that way? Traditionally Reconciliation has focused on the past performance of the mine. In this paper we make a case for Prognostication û the act of forecasting or predicting something in the future from present indications or signs. Reconciliation is a common activity carried out at most mines around the world. Countless geologists and engineers spend hours poised in front of spreadsheets diligently comparing how their resource/reserve model, grade control, and survey pick ups compare to what was actually produced. The result is usually a group of factors, which are applied to future estimates in an attempt to better predict how the operation may perform. Unfortunately, if the road ahead isnÆt the same as what you have just been down, youÆll be æoff-roadingÆ in no time! An alternative is to constantly collect and analyse key measurements that are used to calibrate critical estimates in an iterative process. When variations occur, they are analysed and corrective action is taken to ensure the estimates and measurements realign. In this way the estimates become forecasts and can then form the basis for decision making to ensure that what does happen in the future will match the plan or schedule. By automating this process, some mines have been able to be proactive on a daily basis in order to improve the overall performance of the operation. This paper outlines the key estimates and measurements used for reconciliation, details the characteristics of an automated web based information management system to facilitate the process and provides some insights about how mining operations might move beyond reconciliation.

Jan 1, 2003