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By D K, S Freij, A Rossiter, X Han, B Feng

In mining operations, the removal of overburden to expose the ores is achieved by rock blasting using ammonium nitrate based explosives, eg ammonium nitrate-fuel oil mixtures, commonly known as ANFO. However, ammonium nitrate can react with pyritic shales that are often found in many mines, leading to premature detonation or spontaneous explosion. In order to minimise the occurrence of spontaneous explosion, the reactivity of the shale in a mine must be assessed. This will provide a better understanding of blasting risks and thus will improve the safety and the cost efficiency of blasting through the selection of appropriate explosives. In this study, shale samples were collected from different locations in Western AustraliaÆs Mt Whaleback iron ore mine and geochemically characterised. The reactivity of the shale samples towards ammonium nitrate and ANFO was investigated using a combination of large-scale firing range tests and laboratory isothermal reactor tests. Results of the firing range tests show that the reactive ingredients of the shale are the limiting factor for the reactions between shale and ANFO. Based on the firing range test results, further isothermal reactor tests were conducted to investigate the reactivity of shale samples towards ammonium nitrate under controlled conditions. Analysis of the results from the firing range tests and the isothermal reactor tests shows that there are correlations between the reactivity of shale samples and several geochemical characteristics such as sulfate, sulfur, ferrous and zinc content.

Jan 1, 2005

By B Ellis

Brunswick Mine is one of the largest underground zinc/lead mines in Canada, producing 3.4 million tones of ore annually. As mining activities advance to deeper levels, ground pressure also becomes greater. To cope with the highly stressed ground, the mine has taken some strategic measures to ensure the targeted production level. Such measures include the implementation of a pastefill system and transferring the mining method from primary/secondary stoping to pillarless pyramid stoping. With the pillarless mining method, stope sizes become smaller and the number of active stopes is also less than before. In addition, mining sequence and cycle time have to be strictly followed according to production schedule. The blasting project described in this paper tackles one of the steps in the mining cycle aimed at shortening the blasting cycle time in a stope. Furthermore, this project was conducted and managed with the Six Sigma initiative in Noranda which was implemented in the fall of 1999. Like a typical process review, the blasting operation was examined by breaking it down into many steps that can be quantified and measured. Each activity was then correlated with different factors associated with blast design as well as blast operations underground. It was found that the utilisation of voids plays a key role in the blasting cycle time. With improved void utilisation ratio, blasting cycle time has been reduced from an average of 12 shifts to ten shifts per stope. This improvement translates into approximately 180 000 tonnes of ore being blasted without any increase in manpower. This paper presents the technical aspects of the study, as well as some operational issues and improvements made during the project.

Jan 1, 2001

Completing its historical role the opera tion of copper blast furnace of the Saganoseki Smelter was terminated in 1970, but it left some interesting data on metal lumps formed at the furnace bottom. Analysis disclosed the lumps to be speiss containing 100 to 10,000 g/t of Au and Ag and stratified to iron speiss and copper speiss. Solidifying temperatures of iron speiss and copper speiss being approximately 1,090¦C and 800¦C respectively, copper speiss precipitated at the lower side. The distribution coefficient of Au and Ag between matte and speiss (g/t Au(Ag) in matte / g/t Au(Ag) in speiss) is in the range of 1 x 10 2 to 2 x 10 ' and 1 x 10 1 to 5 respectively. The higher Cu % is in speiss, the-more An and Ag are distributed into speiss. Except for a few data, these results comfotm well to the range of distribution equilibria of Au and Ag in matte and speiss systems by Gerlach and Others.

Jan 1, 1980

By Guerney P. J

A suspension of finely powdered ferrosilicon in water is the dense medium used in the gravity upgrading of iron ore, diamonds and other minerals. Ferrosilicon can he lost in the plant through corrosion. The greatest corrosion losses occur when

Jan 1, 1997

Initial coal production at Ulan was solely from underground mines. A significant increase in demand for steaming coal in the late 1970's emphasised the need to further expand production and led to the development of the open cut mine which commenced commercial production in June, 1982.During the initial stages of mine planning, feasibility and cost studies were undertaken to determine the most suitable method for coal haulage from the pit. The comparison between a conventional truck haulage system and an in-pit crushing system using a mobile crusher and moveable belt conveyor haulage confirmed that the mobile crusher and conveyor system was superior in every respect for the Ulan mining operations.Technical features and design parameters for the major items of equipment are outlined as well as operating, manning and performance assessments. Minor equipment problems were encountered during initial operation but these have since beenrectified and the plant is now capable of exceeding the design production. Maintenance and energy costs are considerably lower than originally estimated and production efficiencies are continually improving as operators develop new techniques and procedures in the handling of the equipment.

Jan 1, 1985

By S Serp, M Duchateau, P Chevreux

Molten salt reactor (MSR) is a promising advanced reactor system aiming to the transmutation of minor actinides such as americium in order to reduce the inventory of ultimate nuclear waste. The fuel is a molten salt in which actinides are homogeneously dissolved in the liquid phase. A chloride salt may be retained for this concept, as it provides low melting point, high solubility of actinides, harder neutron spectrum. To avoid corrosion and precipitation issues, molten salt composition has to be carefully controlled with impurity content as low as possible. Obtaining pure actinide chlorides without contaminants such as oxide, oxychloride, hydroxide and water is still a challenge. To prepare actinide-bearing salt, the chlorination of actinides oxides was investigated in an unstirred reactor under flowing gas as solid-gas reaction. The carbochlorination of PuO2 were performed in the temperature range of 600 to 800°C with chlorine gas as a chlorinating agent and the presence of solid carbon. PuCl3 was successfully synthesised by this method and characterised by X-ray diffraction measurements but some impurities such as oxide phase remain inside the formed product. Refinements of anhydrous and hydrated PuCl3 phases by Le Bail method were also performed for crystalline materials definition. Conversion mainly depends on the chlorinating temperature and the contact between the oxide and the chlorinating agent. A conversion value of 70–80 per cent was achieved at 700°C from PuO2 with quite high specific surface area. The conversion rate was not improved with increasing the chlorination time. The volatilisation of Pu was observed during the carbochlorination experiments. To avoid a loss of Pu caused by sublimation, the chlorination temperature should be limited to 650°C despite that the conversion of PuO2 to PuCl3 was enhanced by increasing temperature. Both carbochlorination and hydrochlorination of AmO2 were also carried out leading to the formation of AmCl3. These first results suggest that americium oxide was chlorinated more readily than plutonium oxide. The purity of produced PuCl3 and AmCl3 still deserves further investigations.

Jun 19, 2024

Because of the coincidental location of orebodies and population in Australia, the mineral sands industry has been subjected to numerous land use conflicts, resulting in the sterilisation of strategic ore reserves and a severe downturn of activity in the eastern states. All tiers of government of various political persuasions were responsible for the decisions leading to this sterilisation. As such, it became a community response to intense land use pressure along an attractive and popular coastline. The resultant high public exposure of the industry has placed it in the forefront of developments in rehabilitation technology. In eastern Australia, the industry has operated in a wide range of ecosystems, many with conservation values. Rehabilitation ech- niques have been developed to suit these varied conditions, and much of this technology is now widely adopted throughout the mining industry. Land use considerations in Western Australia are somewhat different to those of the eastern states. Nevertheless, the same basic principles of rehabilitation apply with modification to suit local conditions and land use objectives. The development of rehabilitation in both Eastern and Western Australia is reviewed, and the direction of future trends is indicated.

Jan 1, 1986

By J Bang, I-H Jung

Ti is an important constituent for steels and superalloys. During the continuous casting process and ElectroSlag Remelting process (ESR), Ti in molten steel and superalloy can have chemical reactions with casting flux and ESR slag containing CaO and CaF2. In order to investigate such exchange reactions, the understanding of the (Ca,Ti//O,F) reciprocal slag system is prerequisite. In the present study, a coupled phase diagram experiment and thermodynamic modelling of the (Ca,Ti//O,F) reciprocal system was performed. In particular, the phase diagram of the CaF2-TiO2 system was experimentally investigated by Differential Thermal Analysis (DTA) experiment and quenching experiments followed by Electron Probe MicroAnalysis (EPMA) phase analysis. The Gibbs energy functions of all solid and liquid phases in the (Ca,Ti//O,F) reciprocal system were optimised to reproduce the present data and all available reliable experimental data in literature.

Jun 19, 2024

By B G. Blacka, O Salisbury, K W. Mills, R G. Jeffrey

Whitehaven Coal Limited operates an underground longwall mine near Narrabri, New South Wales. The mining horizon in the Hoskissons Seam is overlain by a 16–20 m thick unit known as the Digby Conglomerate, a unit that is sufficiently massive to have potential to cause a windblast during first caving at the start of each longwall panel and periodic weighting throughout the panel. A program of hydraulic fracturing has been successfully used to precondition the conglomerate strata to increase its caveability at the start of each panel. This paper presents a system of temperature monitoring that was used successfully to measure hydraulic fractures at Whitehaven confirming their rate of growth, orientation and interaction with previously placed hydraulic fractures.CITATION:Mills, K W, Blacka, B G, Jeffrey, R G and Salisbury, O, 2014. Temperature monitoring of hydraulic fractures used for preconditioning massive conglomerate strata to reduce windblast, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 189–194 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

Fluid circulation occurs in oceanic crust of all ages, at the seafloor spreading axis, on mid-ocean ridge flanks, in the ocean basins, and in subduction zones. In the first three settings the fluid originates as seawater. At the axis and on the ridge flanks, the circulating seawater produces a major chemical exchange between the oceans and the crust. Based on heat budget constraints, between 10 and 40% of the river flux of Mg can be taken up during high-temperature alteration of the basaltic crust along the mid-ocean ridge axis. Most of the hydrothermal -heat loss, however, occurs on the mid-ocean ridge flanks, where the temperatures are lower and the seawater flux correspondingly larger. The estimated heat loss on the flanks is so large that upwelling must occur over a large fraction (5-30%) of the seafloor less than 65 Ma in age, at seepage velocities on the order of 10 to 100 cm/yr. The circulating seawater need lose less than 1 to 2% of its Mg content in order to solve the Mg mass balance for the oceans. Fluids in subduction zones are commonly less saline than seawater and are rich in methane and other light hydrocarbons. These fluids may originate by dewatering of the downgoing slab. If so, they may close the geochemical cycle of H2O that began with hydration of the basaltic crust at the ridge axis.

Jan 1, 1990

In recent years, the. art of electric steelmaking has received a great deal of attention, and naturally, much controversy has existed from time to time regarding the relative merits of different practices and tywes of furnaces. Nevertheless, at the present time, the basic principles of the process are reasonably well established, and by far the greatest percentage of electric steel is a product of the basic lined, direct arc type furnace. Ferro alloy manufacture has demanded the development of furnaces having very different characteristics to those used for steel. Some special alloys, however, require conditions of manufacture which are more closely approached in the steel type furnace, and thus the latter has been adapted where necessary for the production of these alloys.One such alloy, low carbon ferro-manganese, is manufactured at Whyalla, South Australia, in a basic-lined, direct arc furnace, which is used alternatively for the production of alloy steels.BRIEF HISTORY OF THE ELECTRIC FURNACEThe principle of melting by electricity was first applied to the melting of iron in 1879 by William von Siemens, whose equipment consisted of a small crucible into which were introduced two carbon electrodes. Very little practical development took place in the next 20 years, although in 1890 a Frenchman named Heroult designed a direct arc furnace for the production of ferro alloys. At the beginning of the 20th century, several types of furnaces were patented for steel melting, the most important of these being the Heroult, using a direct arc, the...

Jan 1, 1951

By Richards JR, Herbert HK

A basic question in preparing this review was how to define sulphur mineral occurrences as being associated with the Pacific Rim. This question will be reconsidered later. The isotope composition of sulphur- containing minerals may be considered in terms of two primary sources - 1. deep- seated sulphur, devoid of crustal contam- ination with a 634S value near 00/0o and 2. oceanic sulphate which fluctuated in value between +10 and +300/00 over geological time (Claypool et al., 1980). However, minerals have seldom been directly derived from these primary sources as even evaporites have been dissolved and reprecipitated. The marine source is differentiated biochemically and isotopically in recent sediments where sulphide from bacterial sulphate reduction may be significantly depleted in 31S. The question of chemical interaction of ascend- ing magma with upper crustal rocks has become one of degree rather than whether or not it occurs. Mineral deposition is considered increasingly in terms of mixing of fluids and their chemical reactions with rocks rather than direct precipitation from magmas or hydrothermal fluids derived from them.

Jan 1, 1987

By A C. Robertson

Studies by Tennent, Isokangas Pty Ltd (TIP) have indicated that underground quarrying of backfill may be a cost competitive option for providing backfill for specialised situations in underground mining. Situations where suitable bulk fill material may not be available on the surface, and where the total cost of setting up a fill distribution system are prohibitive, could favour the mining of fill material underground adjacent to the stopes being mined. Considerations include environmental impact, scheduling, surface constraints and total costs. The examples quoted in this paper, and the case studies are based on the authorsÆ personal observations and experience.

Jan 1, 1998

At Pasminco Mining's South concentrator. which was commissioned in 1952. an expansion. modernisation and efficiency improvement program commenced in 1986 with a coarse ore stockpile and grinding circuit expansion. the replacement of small flotation cells and the upgrading of reagent mixing and metering equipment. The program continued with the installation of a TDC 3000 based process control system (1988) and concentrate thickeners (1990). By mid-1991 a further grinding expansion and the installation of zinc flotation feed regrind ball mills and zinc recleaner column cells will be complete. leaving the use of ceramic disc fillers and development of process control strategies as probably the remaining major avenues for improved process efficiency at present.

Jan 1, 1991

By Hayward N, Sutherland D, Wilkie G

A pilot plant study has been made of the liberation characteristics of a nickel ore under different milling conditions. A series of runs were made ranging from fully autogenous grinding to semi-autogenous grinding with a ball load of 8%. The mill products were sized and assayed then analysed by QEM4SEM. This enabled a full liberation analysis to be carried out to see whether the autogenous grinding leads to improved liberation by promoting selective breakage. Though it is frequently claimed that fully autogenous grinding yields superior liberation this could not be detected in the present study.

Jan 1, 1991

Studying the ore textures in a discrete orebody is a novel approach to estimating liberation potential of the ore minerals present. As part of a PhD thesis, this project aims at classifying and quantifying the textures of the Hilton North orebodies, and at estimating their liberation characteristics.

Jan 1, 1993

By Arndt MB, Bamberg S

The evaluation of risk is becoming more important in the siting of mining operations in the United States as well as the rest of the world. The determination of environmental, economic, as well as health and safety risks is an important step in the planning of any mining operation. Hydrogeology plays an important role in pre-mine planning and in the determination of these risks. The mine operators must determine if ground water would inhibit mining in any way. Factors which are important to consider include mine dewatering economics, slope stability, and other adverse hydrologic impacts. This paper presents methodologies for the characterization of hydrogeological risks for a mining operation. First of all, the term risk analysis is defined and its utility is addressed. Then, stepwise methods for performing a typical risk analysis are presented. Finally, the application of risk analysis to hydrogeology in mining is given. With slight modification, it is believed that these methodologies can be used to evaluate the hydrogeological risks for any mining operation.

Jan 1, 1988

By C Yeung, N Swa, D Gribble, R Reupana

BlastLiteÖ is a low density explosive developed by Dyno Nobel and has been in use at BHP Billiton Iron OreÆs Mt Whaleback Operation since March 2004. The Mt Whaleback Operation utilises BlastLite because it offers an attractive alternative to ANFO in soft to medium strength rock types. Its use also reduces the amount of liquid fuel oil consumed and is well aligned with BHP BillitonÆs corporate Energy Excellence initiatives to reduce greenhouse gas emissions. This paper presents the:results of characterisation work completed on-site as a fourth year mining engineering thesis, and application and benefits of the product at Mt Whaleback. One of the key features of low density products is that the detonation is non-ideal. That is, the explosive does not react fully in the detonation driving zone. This manifests itself in that the product is highly dependent on charge diameter and confinement conditions. Dyno Nobel has access to the Vixen suite of detonation codes for characterising the ideal and non-ideal behaviour of explosives. The objectives of this work were to use the Vixen_i code to characterise the detonation performance of BlastLite, in order to understand the role of the bulking agent and to allow modelling of the explosive. The detonation performance was established by detonating a series of unconfined charges at various diameters and measuring the velocity of detonation (VoD). The work program consisted of sourcing and preparing cardboard tubes of various diameters (80 mm to 305 mm). The tubes were loaded with explosive at the BHP Billiton Iron Ore Mt Whaleback test range and detonated one at a time. Over the past three years BlastLite has been used in various applications across the site. Initial findings illustrate that shovel productivity from BlastLite shots was comparable to the baseline ANFO blasts. The study results were also backed with visual inspection and feedback from shovel operators. A work program is currently in place to develop different blends of BlastLite and TITAN« BlastLite to tailor the explosives to various blasting applications. The trials at Mt Whaleback are leading to future opportunities of BHP BillitonÆs satellite orebodies.

Jan 1, 2007

The Late Permian intermediate to silicic talc-alkaline Drake Volcanics of New England, N.S.W., consist largely of shallow marine, redeposited volcaniclastic rocks which host epithermal Ag-Au deposits. Pervasive hydro- thermal alteration is widespread. The 200-300 m Cataract River Member includes several sedimen- tation cycles composed of massive pumice brec- cias, overlain by laminated sandstones and siltstones, interbedded with marine, fossil- iferous mudstones. Two distinct groups of cla- sts exist within the volcaniclastic beds: 1. Lithics of predominantly intermediate compos- ition lavas that have undergone subaerial epi- clastic erosion and transportation; 2.Pumice, quartz and plagioclase crystals which have not been reworked by epiclastic processes. The lithic clasts were derived locally in a sub- aerial environment within the Drake Volcanics, and pumice and crystal fragments from contem- poraneous centres of silicic volcanism else- where in New England, N.S.W. The latter group of clasts was transported to Drake by Plinian airfall or rafting, and fell and was washed on- to emergent portions of the Drake Volcanics, where reworked locally derived fragments occ- urred. Cold state subaqueous mass-flows, prod- uced by slumping, resedimented the mixed vol- caniclastic detritus into the marine basin in a series of cyclic units with massive lower parts, and laminated upper zones. Modern ana- logs of the palaeogeographic setting in New England, N.S.W., in the Late Permian are pro- vided by the Taupo Zone, New Zealand, and sou- thern Kyushu, Japan.

Jan 1, 1987

By D Elmo, M Scoble, Y Liu, B Klein, J Scholar, S Nadolski

A cave-to-mill study being conducted at the New Afton block caving operation demonstrated the potential for sensor-based ore sorting equipment to reject waste and improve the grade of feed to the mill. The lack of selectivity and potential for dilution entry associated with the block cave mining method results in many caving operations having to mine and process material that is below cut-off grade at certain stages of production. Online monitoring and bulk sorting systems have the potential to alleviate this problem and improve the productivity of caving operations while reducing energy and water requirements for each tonne of concentrate produced.As part of the cave-to-mill study, the suitability of a range of sensors, such as X-ray fluorescence and induction-type sensors, to sort mine production at the New Afton mine was investigated. Results showed that the discrimination of ore and waste can potentially be carried out by implementing surficial sensors into the material handling system. The study also showed that a combination of sensor outputs could be used to identify a certain ore type so that pre-emptive changes can be made in the mill to improve beneficiation performance. Overall, the outcomes of the study on implementing sensor systems at block cave mines are considered to be of significant relevance to a number of existing and future caving operations.CITATION:Nadolski, S, Klein, B, Elmo, D, Scoble, M, Liu, Y and Scholar, J, 2016. Investigation into the implementation of sensor-based ore sorting systems at a block caving operation, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 393–400 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016