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IN this paper it is proposed to present certain features of operating practice at the Port Pirie works of The Broken Hill Associated Smelters Proprietary Limited, in the smelting in a blast furnace of lead ores carrying a high concentration of zinc.The subject matter selected for presentation is:(i) The effect of zinc on lead blast-furnace operations, together with an outline of the methods adopted in actual practice in dealing with the zinc problem.(2) Development of the height of tuyere above the bottom of the jacket, and the extension of the tapping interval and the combined effect of both factors upon the lead content of blast furnace slag.It will later be seen that one phase of the investigation carried out in connection with the effect of zinc on blast-furnace operations was largely responsible for the decision to increase to a marked degree the height of the tuyere above the bottom of the jacket.Due to this interdependence, it has been considered advisable to deal with the two features above mentioned.The high concentration of zinc in the lead-bearing materials smelted at Port Pirie has brought with it those troubles which are associated with zinc in the smelting operation.In the early stages of the history of The Broken Hill Associated Smelters Pty. Ltd. the trend towards increasing cost for labour, fuel, and stores, etc., rendered it necessary to increase the lead content of the charge, and reduce to a minimum the quantity of barren flux used.

Jan 1, 1931

Obtaining correct assays for gold determinations relies on the correct methods being chosen and the assayer being made aware of the mineralogy of the sample and its general origin. Usually when a geologist or metallurgist obtains "incorrect" gold assays the problem can be traced to poor communication between the geologist or metallurgist and the assayer.

Jan 1, 1986

By C Ferron, R Massimi

There is approximately 240 000 tonnes of arsenic trioxide dust stored in underground chambers at the Giant Mine in Yellowknife, Northwest Territories, Canada. To minimise the amount of arsenic released to the environment, a number of closure alternatives are being considered. One alternative is to mine the dust, encapsulate it and dispose the mixture into a secured landfill. The potential leaching behaviour of the encapsulated dust was examined in a laboratory programme. Cylinders of arsenic trioxide dust mixed with cement/aggregate and bitumen were prepared. The dust content varied between zero per cent and 60 per cent of dry weight charge. The cement cylinders were tested for strength, leaching and freeze/thaw durability. The bitumen cylinders were tested for leaching only. The results show that increasing dust content in the cement cylinders negatively impacts the strength and the freeze/thaw durability of the samples. A contributing factor is likely the high water to cement ratio in the samples. Leaching tests show that arsenic release from cement cylinders increase with increasing dust content. Arsenic concentrations in leachates do reach a plateau at a certain point in time. Arsenic release from bitumen cylinders was significantly lower compared to cement cylinders. Arsenic concentrations eventually were less than 0.05 mg/L in samples containing up to 25 per cent arsenic trioxide dust. Arsenic leaching rates were found to decrease by an order of magnitude over the course of three months.

Jan 1, 2003

This evening I would like to speak about men for the mineral industry.It is trite to say that the mining industry is expanding rapidly and that technically trained men are in short supply. How short is difficult to assess and impossible to quantify.The industry has been traditionally managed by technically trained men experienced in the ways of their fellow men. Let us start with the assumption that men with this training and experience are essential to management of mining and metallurgical enterprises.I suggest that we do this as it avoids argument with those who are beginning to suggest that such men are not so important as they used to be; who are suggesting that the latest sophisticated business management schools can produce managers who can straight out of school join the upper echelons of an organization and successfully manage it by the use of modern systems and techniques without the need to rub shoulders with men of all callings and get their hands dirty in the process.This kind of thinking brings to mind the modern cargo ship which is equipped with all the latest gadgets of science. It can find its way from Sydney to Auckland with no one in the engine room and the man on the bridge spending most of his time writing to his wife or reading the latest novel.How often do we read of this ship being tied up in Sydney because the crew sympathizes with the cook who has been slighted by some uncomplimentary remark about his toheroa soup? Here is a pieceof sophisticated machinery stopped through no technical fault, but held up by the whim of man. The understanding of man by man can spell the success or failure of any endeavour. A single man can leadan organization to the pinnacles of success, or doom it to utter failure in spite of modern systems and techniques.So let us start from the point that people matter.Through the years our Institute has been fortunate in having many members who have felt strongly...

Jan 1, 1970

Casing or lining pipe is used in boreholes for the following reasons:1. To preserve the hole while drilling and after it is finished.2. To shut water out of the hole or to isolate any particular water, gas, or oil-bearing stratum.Deep holes can seldom be drilled without casing, and only when in firm strata. If caving from the walls is at all likely while drilling, casing is necessary in order to prevent the tools horn being buried...

Jan 1, 1924

Lightweight polymer grids have recently been introduced to the mining industry. They are currently being used for roof and rib control, longwall shield recovery, safety guarding or barricade, highwall screening, internal reinforcement of gunnite/shotcrete applications, sub-base reinforcement, construction of steepened slopes, retaining walls, mine reclamation (i.e. erosion control, turf reinforcement), and in numerous mining waste related projects. These polymer mining grids utilize a strong, lightweight polymer, usually special grades of polypropylene or polyethylene. High tensile strengths are achieved by molecular orientation of these polymers in the manufacturing process. The first step in the manufacturing process is to extrude the polymers into thick continuous sheets. These sheets are then punched, and drawn into open grid structures. Aperture size and configuration are controlled by the geometry of the punched hole and the degree to which the grids are stretched. The drawing process is the key to the molecular orientation required for the tensile strengths. These long chain polymer molecules in their natural state have a random orientation. When stretched, the molecules are pulled into a parallel alignment, thus creating a lightweight product with tensile strength comparable to Steel.

Jan 1, 1992

By Kavanagh M. E, Henley R. W

The Meekatharra mining district lies in the northern pan of the Murchison Province of the Archaean Ynlgam block of Western Australia. Since dis- covery of the Paddy's Flat belt in the district in 1897 total gold production has been 67 tonnes and a further 33 tonnes in resources have been defined by drilling. The Paddy's Flat gold deposits occur within the Gabanintha Formation, a basal formation of the Murchison greenstone sequence containing komatiitic basalts, ultramafics and minor banded iron formations. The regional control on the distribution of deposits is an anastomosing shear belt which extends over 350 km and incorporates the Mt Magnet, Reedys and Meekatharra deposits. The following gold deposit styles may be recognized based on lithological association and alteration: Albite porphyry hosted, Carbonate-fuchsite- quartz alteration hosted deposits, Banded Iron Formation hosted sulphide replacement gold deposits and quartz vein deposits. With the exception of the banded iron formation hosted deposits, the Paddy's Flat alteration zone shows strong similarities to the alteration styles at Kerr-Addison (Ontario).

Jan 1, 1991

Although laterite ores already provide a significant proportion of the world's nickel and cobalt production it is anticipated that they will surpass sulphide ores as a source of nickel in the next century. The most recent period of greenfield nickel project construction was during the 1970s when it was notable that all of the eight new plants were based on treating laterite ores. This was because of the relatively large selection of available high grade laterite ore deposits amenable to cheap open cast mining and a paucity of high grade sulphide ore prospect alternatives. Of the three processing options for treating laterite ores: 1. smelting for the lower horizon saprolite ore, 2. ammonia; and 3. acid leach for the upper horizon limonite ore, smelting currently accounts for about 80 per cent of nickel production. In the future, as saprolite ore grades decline because of relatively high exploitation rates, the incentive to process the large untapped reserves of limonite ore will increase. The high cobalt content of limonite ore also makes it ideally suited to processing by a hydrometallurgical rather than smelting route. With only two exceptions, all saprolite smelting operations have a Class 2 nickel end product (largely ferronickel) and do not produce a cobalt by-product. As a result of technological advances, the modified ammonia leach process for limonite and transition ore as undertaken at Yabulu, now allows the production of pure nickel metal as a Class 1 product, along with significant tonnages of cobalt by-product. The mixed Ni-Co sulphide intermediate product of the pressure acid leach processing of limonite ore at Mon is converted to Class 1 nickel and cobalt metal at Fort Saskatchewan, Canada.

Jan 1, 1996

By J Araya, O Leiva

The mine evaluation process, composed of the designing, planning and valuation of a mine project, is, among other variables, based on an estimated orebody model. However, as the information from the drill holes is limited, it is impossible to know with certainty the mineral content in each block within the estimated block model. Consequently, uncertainty about the value of metal grades, or other geological attributes, arises because of the lack of information at unsampled locations. This is one of the reasons why, in any mine operation, there will always exist a divergence between estimated and real values. Cut-off grade optimisation is the process used to determine the operating mining strategy (long-term production scheduling) that will maximise the total profit value (normally referred as the net present value (NPV)) of a mine operation. This is done by defining a dynamic cut-off grade policy which is constrained by the production capacity of the mining, mill and refining.Real options is a type of contract, written on real assets such as mining, oil and other natural resource industries, that gives you the right but not the obligation to exercise the contract. It is based on operational and managerial flexibility, which allow mine decision makers to react to either good or bad operational and economic events in the future. But, what do geostatistics and cut-off grade optimisation have to do with the application of real options in a mine project evaluation process? The objective of this paper is to answer the previous question by showing how geostatistics combined with cut-off grade optimisation are key tools for corporate/managerial decision makers, which allow them not only to analyse the resource/reserves of their projects, but also to generate operational strategies that can maximise project value by minimising the downside risk due to ore tonnes and grade uncertainties, while achieving operational and physical constraints such as mining and processing capacities. A real copper grade open pit mine project is used as a case study.

Sep 26, 2011

Rehabilitation, reclamation and restoration are all terms used to describe the repair of land after mining. Here, restoration is used to mean restoring the land's original use, capability or productivity. Effective restoration is dependent on good planning before mining commences and must include a clear definition of post-mining objectives. The physical condition of the land within the mining licence was that of an imperfectly drained soil in permanent pasture, supporting a seasonal supply dairying unit. During the mining process, the soil layers were separated, with the topsoil stockpiled separately. As part of the restoration process, the land was recontoured to encourage surface drainage, with topsoil spread evenly over the recontoured tailings. Low grond pressure machinery was used to minimise soil compaction, with light discing and harrowing used to increase water infiltration. A permanent pasture was sown, with weed species controlled by spraying, both before and after pasture establishment.  Soil testing has been used extensively to ensure there were no nutrient deficiencies that good compromise pasture establishment and performance. Controlled grazing practices were used to ensure that the sown pastures became well established.

Jan 1, 1998

By J Parmenter

Issues around water û its quality, use, availability and environmental value û can be a major point of tension between mineral projects and local communities. Failure to manage these issues appropriately can jeopardise the obtaining of regulatory approvals for new projects and place at risk the æsocial licence to operateÆ of existing operations. Conversely, there may also be significant opportunities for companies to engage constructively with communities over water issues and to make a positive contribution to the sustainable development of these communities. Using case studies, this paper will explore the various types of social risks and opportunities associated with water and mineral resource development and identify key learnings relating to the management of these issues.

Jan 1, 2006

Upon cessation of mining activity open-cast mine pits typically fill with water, forming a æpit-lakeÆ. The water in these lakes, in some instances, contains high concentrations of ædeleteriousÆ material. Containment and/or dilution typically requires an understanding of how stratification in the pit-lake will develop over a long timescale (say 100 years). Vastly different transport rates can develop due to differing hydrogeochemistry, basin morphology and climate. Numerical (computer) modelling is the most likely approach for successful prediction over long times. While lake modelling tools are available, useful numerical modelling requires improved understanding of transport in such systems because they are different to natural lakes in a number of ways. Notwithstanding the effort required to improve our understanding, the modelling provide a means of testing approaches to active management of pit-lakes.

Jan 1, 2002

Support design in jointed or blocky rock masses is often approached by the use of either 'rules of thumb', rock mass classification systems such as the Q-system (Barton, Lien and Lunde, 1974) or RMR (Bieniawski, 1973) or conventional wedge analysis. Generally, this requires that a number of key simplifying assumptions are made and the support system is designed to cater for either a mean, most likely, or worst case scenario depending on the risk tolerance. The design block size is often a major uncertainty and often a worst case block size based on excavation span is used. Thompson and Windsor (2007) state that it is inappropriate to base support designs on the excavation size as these size blocks rarely occur if discontinuity trace lengths are considered. Probabilistic keyblock methods can be used to determine the most likely design block sizes. A methodology is presented whereby JBlock software (Estherhuizen, 1996) is used to estimate potential block sizes as part of the support design process. Using information such as the spacing, orientation and length of discontinuities, it is possible to simulate blocks in the walls of an excavation (Esterhuizen and Streuders, 1998). Keyblock analysis methods (Goodman and Shi, 1985) are used to evaluate whether blocks are removable and whether the chosen support will be sufficient to ensure stability. Data from two mines is used to demonstrate how probabilistic keyblock analyses can be used in support design. Discontinuity data was used to generate 10 000 removable blocks and the design block size statistics were determined. For one mine this information was used to scale blocks in a conventional. Unwedge analysis whilst for the other mine, the point estimate method (Harr, 1987) was applied. The choice of appropriate design acceptance criteria in terms of factor of safety and probability of failure is also considered.

Nov 25, 2010

By S M. Iveson, K P. Galvin, D Kumar

Dry separation of iron ore fines and other heavy minerals has previously been achieved using one of two main approaches. The first is an inclined table with an upward airflow via small holes to help form an autogenous dense medium. The second is based on fluidised beds comprising a dense medium formed by fine particles suspended in an upward flow of air. In either case, vibration can be introduced. This paper describes recent findings using a novel system referred to as the Sink-Hole Fluidiser, which utilises elements of both these two former approaches. This device consists of a conventional gas-fluidised bed of fine medium with a 1 mm aperture mesh located at the surface. This mesh contains relatively large holes that act as sink-holes. The fluidised media flows upwards through the sink-holes and then falls back into the fluidised bed via the fine apertures in the mesh. The particles being separated, which are much larger than the fine media, pass over these sink-holes, where they either sink or float. The sink-holes offer a more precise balance of forces, applied on a single particle basis, resulting in robust density separation.Experiments have been performed using 2.0–4.0 mm tracer particles of density varying from 2.4 to 4.8 relative densities (RD) separated in a 200 mm diameter Sink-Hole Fluidiser with a single 13 mm diameter centrally-located sink-hole. In this preliminary semi-batch work, it was found that the Sink-Hole Fluidiser was able to achieve sharp separations (Ep as low as 0.20). This work underpins the development of a new continuous steady-state Sink-Hole Fluidiser, applicable to the dry separation of iron ore fines.CITATION:Kumar, D, Iveson, S M and Galvin, K P, 2017. A novel sink-hole fluidisation method for dry separation of iron ore fines, in Proceedings Iron Ore 2017, pp 221–226 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

Partnering has come to prominence in the Australian construction industry in a formal sense this decade. The high level of disputation in the building and civil construction industries in the 1980s drove its development in both Australia and North America. PartneringÆs use has been most prominent in the construction industry, particularly in the civil and construction sectors of the industry. It has found favour in some mining development projects, one of the most notable being BHP MineralÆs Cannington project in NW Queensland. This paper examines the requirements of successful partnering agreements and describes in detail the mine development partnering agreement at Cannington. In particular, the paper discusses the authorÆs experience and recommendations for partnering to avoid contractual problems and achieve win û win project outcomes for all parties to major mining projects.

Jan 1, 1999

ABSTRACTFor the binary system copper-lead two relationsEquation 1andEquation 2have been derived for the activities of copper and lead at compositions and absolute temperatures within the liquid region of the phase diagram.These relations give, with greater accuracy than is given by previously published relations, the activity-composition temperature variations for all regions of the phase diagram of interest to metallurgists.These relations are essentially simple forms of the Margules equations but with linear temperature dependence applied to their coefficients. This has been done in such a manner that a phase diagram obtained from these relations agrees well with the data available for this system. The methods of obtaining the relations and constructing a phase diagram from them are both given in detail. The enthalpies and entropies of mixing are compared with those derived by other methods.

Jan 1, 1971

Much of the coal and gold mining industry of New Zealand is small scale. Funding is tight and mechanisation limited. The country has many well documented small coalfields (some with significant outcropping) and alluvial gold deposits. These are generally remote, difficult to access (physically and otherwise) and of submarginal value (largely a consequence of size when viewed for extraction by traditional techniques). The industry is also burdened by environmental and bureaucratic constraints. The above over simplified setting suggests to the Author, a newcomer to New Zealand, the opportunity to consider some novel concepts based on technology and techniques developed overseas or borrowed from other industry sectors. The objective being to make viable in economic and environmental terms projects that might otherwise be stillborn if considered for exploitation by conventional means. The paper mainly discusses 2 concepts focusing on the application of augers for exposed high wall or outcrop coal and micro-tunnelling augers for alluvial gold extraction. These may be considered high mobility 'container' (as in shipping container) packaged, or 'non invasive' mining systems. It is stressed that these are but concepts and have yet to be subjected to rigorous financial or engineering scrutiny. This could only follow their acceptance by, and input from, New Zealand miners. There will also be brief mention of a new modular conveyor system which might have application within the concepts or existing small scale mineral extraction operations and mention of a project currently in progress to apply tangible 'sustainability' to underground coal mining.

Jan 1, 1996

By Turco E, Pelizza S, Castellani F, Stanganelli V

Excavation are in progress for the building of tunnels of the waterworks in West Campania (Naples). The works afferent to part II envisage tunnelling through a miocenic clay formation over consolidated by two tunnels whose sections are respectively 50 and 10m2. Tunnel blasting is carried out by mechanical means. An excavator is used in the big tunnel, whereas in the small tunnel a roadheader machine is used for a short tract and a mechanized shield is used over a long stretch. The tunnel feature complex problems regarding stability. This is particularly so for the big tunnel whose face appears unstable. For this reason the clay on the face is sistematically bolted by means of 3-metre and 12-metre bolts. This prevent the use of a TBM for tunnel Excavation.

Jan 1, 1987

By I M. Platten, Y Xie

Complex gold deposits are generally characterised by variable geometries, strong structural controls on grade distribution and a high-nugget effect. The use of diamond drilling and fire assays in this environment often results in an understatement of grade. Bulk samples are likely to be the closest estimators of true grade, and may be required to evaluate geological/grade risk during resource estimation/feasibility studies. Any bulk sampling program requires appropriate planning and implementation. The planning stage should attempt to delimit the extent and nature of mineralisation; characterise mineralogy and metallurgical properties of the ore; and define bulk sample size and how it will be sampled/processed. The approach to sample processing will be governed by the results of metallurgical testing and geological knowledge. Careful design of sampling protocols must be undertaken through material characterisation, understanding of gold particle sizing and the application of GyÆs Sampling Theory.

Jan 1, 2008

The Khanong supergene-enriched copper resource, (~23 Mt at 3.0 per cent Cu), is one of several resources recently discovered in the intrusive-centred, sediment-hosted Au-Cu Sepon mineral field located in southern Lao PDR. The unusual style of hypogene mineralisation and unique set of conditions have resulted in the development and preservation of a supergene-enriched profile in this subtropical climate. Hypogene sulphide-rich mineralisation replaced calcareous cataclastite (fault rock) developed in the flat-lying, extensional, Khanong Fault. Spatially, the hypogene mineralisation was immediately out board of the skarn û hornfels Cu-Bi front and in board of sediment hosted Au-(As-Sb) mineralisation in a zoned intrusive-centred hydrothermal system. In situ supergene enrichment of the sulphide protore has resulted in a high-grade chalcocite-clay zone (~10.3 Mt at 4.6 per cent Cu) overlain by leached limonite-clay. A very high-grade in situ to exotic limonite-clay Cu-oxide-mineral zone is locally developed above impermeable dolomite at the base of chalcocite-clay zone. Exotic Cu-Mn-wad mineralisation developed for up to 1 km down the hydraulic gradient from the chalcocite-clay zone. Unique supergene enrichment conditions have resulted in the high-grade Khanong Cu resource in a subtropical weathering environment. The base of the currently active supergene profile coincides with the base of a flat-lying, pyrite-rich fault rock, dipping parallel to the hill slope, maximising Cu enrichment. Meteoric water has been channelled along subvertical faults and narrow horizontal subsurface zones. Low permeability of the fault host rock and footwall rocks has controlled the low volume and slow movement of groundwater required for supergene enrichment. Erosion has been slowed by the resistive ironstone and limonite-clay layer at surface, which assists in preserving the gentle slope over the chalcocite-clay zone.

Jan 1, 1999