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AND INTRODUCTION The Lochiel coal deposit, a large Tertiary soft brown coal deposit in the mid north of South Australia, is currently being investigated by the Electricity Trust of South Australia (ETSA) as a potential source of fuel for a base load power station. Feasibility studies indicated that the proposed dragline method of overburden removal was viable but economically sensitive to both highwail and dump batter angles. The unusual properties of the unconsolidated overburden sediments and the groundwater regime posed a number of intimately related hydrogeological and geotechnical questions which were addressed before and during the excavation of a trial pit. All strata at Lochiel are of soil strength, and artesian aquifers occur above and below the coal. From the initial evaluation of the deposit a number of hydrogeological questions were defined. These related to the rate at which the pore pressure in the silts is reduced by dewatering, the extent of the reduction in pore pressure due to prestripping, and the feasibility of dewatering and depressurising carbonaceous silty sand sequences. The site of the trial pit was selected to answer these and other questions from the basis of a detailed geological, hydrogeological and geotechnical understanding. The trial pit dewatering system simulated a full scale mine dewatering system and included ten pumped wells, twenty drainage wells, and nearly 400 monitoring instruments. It operated from September 1986 to June 1987. The excavation was carried out between February and May 1987.

Jan 1, 1988

By Mur D. M

Metal ferrites are formed by the high temperature reaction of various metal oxides with hematite and are commonly found in the calcines derived from the sulfation roasting of zinc, copper and nickel sulfide concentrates. The Jarosite Process is designed to treat such zinc ferrites by hot acid dissolution but little information is available on the basic reactivity of various ferrites and the effect of Eh. As part of an overall study of the reactivity of calcine products from copper and nickel sulfide concentrates it has been found that Eh plays an important role in the rate of dissolution of magnetite, hematite and nickel oxide by HC1 and H2SO4. Further studies on the reactivity of pure synthetic copper,zinc,and nickel ferrites also show a dependence on Eh. This paper discusses the relative reactivity of iron oxides and metal ferrites in 1 M HC1 and the results of electrochemical studies using cyclic voltammetry. A mechanism for the dissolution reaction is proposed as well as factors which determine their leaching. It is shown that the rate of leaching of metal ferrites with HC1 is enhanced in the presence of reducing agents such as Cu(I) and Sn(II). By contrast the leaching of NiO is enhanced by oxidising agents such as Cu(II).

Jan 1, 1987

Application of Agitated Leaching for Iron Removal from Silica Using Sulfuric and Hydrochloric Acid In this research, iron removal from silica used in glass industry was investigated using agitated leaching method. Silica sample was provided from silica concentrate originating from Chalchoog Silica Mine located in Abhar, Iran. The sample contained silica, iron oxides and clay minerals. For characterization of samples XRD and XRF analysis and atomic absorption method were applied. Silica and iron oxide (Fe2O3) grade of head sample was 98.41 per cent and 0.067 per cent respectively. Two inorganic acids (sulfuric and hydrochloric acid) were used in agitated leaching tests. Two series of L9 orthogonal array of Taguchi design with replication were used to determine the effect of parameters including acid dosage, leaching duration, ambient temperature and solid content on iron removal. The statistical calculations and analysis of variance (ANOVA) were carried out by means of DX7.0, Minitab14.0 and Winrobust1.02 softwares and also statistical calculations were checked manually using Excel software. Also multivariate regression was applied in order to forecast Fe2O3 conent of final product. The optimum conditions for leaching tests which sulfuric acid was employed are as follows: 40 minutes leaching time, temperature of 85¦C, 40 g/L acid concentration and solid content of 20 per cent. Under this condition the amount of iron oxide in silica was decreased to 0.042 per cent. The optimum conditions for leaching tests which hydrochloric acid was employed are as follows: 80 minutes leaching time, temperature of 75¦C, 30 g/L acid concentration and solid content of 20 per cent. Under this condition the amount of iron oxide in silica was decreased to 0.035 per cent.

Sep 13, 2010

By Quast K. B

The effects of metal ion addition rates and contact time on the activation of synthetic sphalerite using copper, cadmium and silver ions were determined in order to investigate the exchange characteristics at the mineral surface. The stoichiometry of the adsorption indicated that the activation of sphalerite involved both a simple ion exchange and redox process in which the activating ion and oxygen were reduced, and the mixed-sulphide surface was oxidised to produce elemental sulphur and a metal-deficient sulphide surface. Unactivated sphalerite was shown to be relatively hydrophilic, with recoveries usually less than 20 per cent for a five-minute float. Activated sphalerite could be readily floated without the use of a conventional collector. This inherent flotability of the activated sphalerite had previously been associated with the formation of a metal-deficient sulphide layer; however, this study emphasizses the significance of the surface oxidation processes occurring.

Jan 1, 1993

The results of the washing of coal are often presented by using Partition Curves. By analogy, it is possible to express the results of screening by using similar partition curves. As in the coal washing processes, this method determines the accuracy of screening and is also suitable for different separations depending on the difference in size distribu- tion. This method compares the effectiveness of two screening operations and forecasts the performances.

Jan 1, 1984

By Grant BPM

The lower levels at the CSA Mine have been developed to mine reserves between theNo.7 level and No.9 level.Work on major excavations for the project began during 1982 with the develop-ment of the crusher chamber, on No.9 level. The brows and walls were pre-dowelled to improve stability before mining by mass blasting techniques.At the same time work commenced on theextension of No.2 Shaft from No.7 level toNo.11 level. The shaft was stripped, using hand held drilling, to a raise bored holeand concrete lined to a diameter of 5.5 metres. Plats were developed at No.8 level, No.9level and the loading station.

Jan 1, 1985

By C Tukel

Copper sulfate is traditionally used to activate various types of sulfide minerals. The list of users includes Falconbridge Sudbury operations, where copper sulfate solution is added to the pyrrhotite/pentlandite middlings at the scavenging stage. Results from some batch tests reported in the literature suggested that copper activation is helpful for the improvement of pentlandite recovery, especially in the difficult to float fine particle range. Any improvement in pentlandite recovery is important since it is the main nickel bearing sulfide mineral. The impact of copper sulfate for this function has been investigated. Since the focus of current investigation was the flotation behaviour of minerals at the scavenger stage, rougher flotation was kept as constant as possible at two different weight recoveries, namely 13.2 per cent and 15.5 per cent that is relevant to industrial practice. Samples taken during batch testing were extracted using DETA and flotation products from selected tests were analysed to determine the recovery by size behaviour in relation to the use of copper sulfate. Results provide significant evidence that the addition of copper sulfate to these middlings does not yield greater nickel recovery, either on an overall or specific particle size basis. It is concluded that copper sulfate is wasted in the process and that self activation behaviour of the ore at a slightly reduced pH is sufficiently significant to maintain the scavenger recovery of pyrrhotite and pentlandite at desirable levels. Results obtained from limited circuit trials have shown supporting evidence for this conclusion.

Jan 1, 2005

By O Aydan, R Ulusay

Blasting is the most commonly used excavation technique in mining and civil engineering applications. Blasting induces strong ground motions and fracturing of rock mass in rock excavations. Particularly, high ground motions may also induce some instability problems of rock mass and structures nearby. Furthermore, it may cause some environmental problems due to noise as well as vibrations of structures near the populated areas. Furthermore, flyrocks is another major issue for the safety of people and damage to machinery and equipments when blasting is employed. In this study, the authors explore the ways how to estimate the ground motions as a function of distance, amount of explosive, number of holes. The ground motions were measured by stand-alone accelerometers developed by the first author and some empirical relations are developed. The effect of ground motions on the instability issues of benches such as sliding, toppling and rockfalls were investigated. Furthermore, the flyrock issue is investigated and some empirical relations to estimate the maximum distance of flyrocks from the blasting relations are compared and discussed. CITATION:Aydan, O and Ulusay, R, 2018. The ground motions induced by blasting in open pit lignite mines and its environmental effects, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 142–151 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By Grace B, Cunningham D

The poor quality of bore waters available to the Australian mineral processing industry creates a climate for crystallization of calcium based scales. If ignored, calcite and/or gypsum buildup can cause loss of production and costly unscheduled maintenance. This paper discusses the factors which contribute to scale forma- tion, methods used to monitor buildup and preventative measures (mechanical and chemical) that can be used. A case history il- lustrates the value of using chemical antiscalants.

Jan 1, 1991

By Bruce P, Luyendyk

The South Island of New Zealand comprises a collage of distinct tectonostratigraphic terranes. Some tectonic models predict that these terranes formed on or near the margin of Gondwanaland. However, geologic evidence suggests that some of these terranes may be exotic. Over 400 samples from 30 sites were collected from the Brookstreet terrane within the Takitimu Mountains. The section includes the early Permian Takitimu Group and the late Permian White Hill Intrusive Suite. Over 80% of the rocks show a partial or complete regnetization in the present field due to recent acquistion of VRM. Although some remagnetization of the Takitimu Group occurred during the emplacement of the White Hill Intrusives, both early and late Permian direction have been isolated. These directions indicate a mid-latitude origin for the Brookstreet terrane, and suggest a strong clockwise rotation between early and late Permian time. A published paleomagnetic result from the younger, but related, Murihiku terrane suggests that the Brookstreet terrane was sutured to the margin of Gondwanaland by the late Triassic, or that the Brookstreet and Murihiku are two distinct terranes.

Jan 1, 1987

By R Atmuri, W Liang, R Prasad, Y Liu, E Wingate

Yellow phosphorus (YP) has been commercially produced since the 1920s. First in the USA by the Tennessee Valley Authority (TVA), next in Russian (Kazakhstan) in the 1950s, and finally in China in the late 1970s and early 1980s. There are operations in Vietnam and Sarawak on a smaller scale. YP has become very in vogue due to its use in the production of lithium iron phosphate battery cathode precursor materials by the Chinese and other western battery manufacturers. The YP is also used to produce purified phosphoric acid and higher grades of acid using a thermal oxidation process after smelting. This paper will look at the basics of the smelting including slag chemistry, alloy chemistry and offgas chemistry. The paper will look at the design of the furnaces used in the YP production process as well as the downstream recovery of phosphorus from the smelter off-gas stream to YP. The next part of the discussion will focus on the operations of a YP smelter with regards to control of the furnace to optimise phosphorus recovery to YP. Will discuss tapping cycles for alloy and slag with a view to optimal phosphorus recovery. The discussion will close out with a review of operational challenges in the smelter and a brief description of the downstream conversion of YP to high purity phosphoric acid.

Aug 21, 2024

Although the 'exi'stence of bauxite in Australia has been known for many years it is only recently that exploitation has commenced.. of the two most' important` deposits, strangely at almost diagonally opposite tips of the continent. Recognition of the importance. of the bauxite in the South/West corner came about initially through the efforts of a well-known Australian mining company which,` with some outside financial help, tackled the early exploration with commendable foresight and courage.

Jan 1, 1964

Mine planning is difficult. Even for small operations, it involves reasoning with complex variables and the practical difficulties of mining. It is also about predicting and planning the future in an unpredictable physical and economic environment. Yet we rely on a handful of individuals and their spreadsheets to tell us how to do it û planning the business and activities of mining to hopefully produce results that will please stakeholders. Does it work? Not as well as it could. Planning affects everyone in the organisation. Company executives are demanding more reliability and stability in cost and revenue forecasts from their operations. Management want to explore ways of being more cost effective. Miners and contractors want more useful plans and realistic targets. And the planners have to describe the method that will translate business objectives into implementable plans. Even with the use of computer technology a lot of effort is expended to produce plans that are largely qualified by the level of knowledge and experience of individuals. Better use of information and the application of Intelligent Technologies can improve the quality and reliability of mine plans and schedules. By capturing the knowledge within the organisation and speeding up the planning process, Intelligent Technologies allow more options to be considered more rigorously. But it is not just about technology. It is about how technology is implemented and embodied in the way the business is managed for performance. When this happens, the real benefits of better planning start to flow.

Jan 1, 2003

Sishen uses a state-of-the-art tracking system to track material from its position in blast blocks through various stockpiles and crushers. Qualities are blended directly to the crusher as opposed to blending from stockpiles. This poses an interesting challenge to the planning department to simulate these conditions. The software used in these simulations are Whittle 4X and Maximiser for long-term planning, Xpac for medium-term planning and Mine Works Planner for short-term planning. Geological models and mine design layouts utilise Surpac. Sishen introduced Xpac a number of years ago; the system has developed and changed over the years. With the Sishen Expansion Project (SEP), which aims to utilise low-grade material, major changes to the planning process have to occur. SEP requires that the mine have two different plants, which utilise two different ROM feeds and have different beneficiation curves. Xpac is used to produce a rolling 18-month plan, which is as close to actual operations as possible. In order to do this, the simulations have to take into account the plants beneficiation curves, stockpile movements, hauling distance and equipment needs. On top of this, the schedule has to continually consider specifications for Fe and the contaminants. Plant yields also have to be kept within a certain bandwidth. Xpac is used to simulate the above parameters, as well as generate the raw data required to produce a mine budget. The paper will also show how the 18-month planning process and subsequent planning processes are measured and aligned. Xpac has proved to be an excellent tool to achieve these goals.

Jan 1, 2005

By B T. Qin, C Zhu, Y W. Jia, Y Lu, F L. Li, Q L. Shi

Air leakage through rock fractures in coal mining is a major cause of coal spontaneous combustion. In order to overcome the deficiency of the existing fire control technology and prevent coal spontaneous combustion by isolating coal from oxygen, the article proposes a novel technology of inorganic solidified foam (ISF) with high expansion to fill fractures effectively. ISF consists of fly ash, cement, setting accelerator, redispersible polymer powder, water and aqueous foam. For preparing homogeneous and stable ISF, a preparation system with a pore type foam generator, a mixer device installed with a hollow shaft and helical blades, air compressor, slush pump and monitoring instruments was developed, and the working principles of key devices were elucidated. Based on a series of experiments on the different ratios of each component material and technological parameters of the preparation system, ISF with a foam expansion ratio of 8~10 and dry density of 250–400 kg/m3 was prepared. The relationship between elastic compressive strength, modulus of elasticity and density was summarised. Based on the injection experiment for fracture of loose coal pile with high temperature, the characteristics of sealing air leakage, compressive strength, thermal insulation, flow and cooling of ISF in the fresh state were investigated, indicating that ISF can effectively cut off the air leakage and cover the coal sample to reduce the temperature in the earlier stage, and ISF can remain stable and not crack. The ISF was applied to Luwa coalmine to seal small coal pillar pressure fractures and loose coal fractures in goaf. After press-casting the ISF in Luwa coalmine, the pressure-difference of inner-outer increased, meaning the effect of external conditions on the pressure-difference decreased, showing that it could plug the air leakage effectively.CITATION:Qin, B T, Shi, Q L, Lu, Y, Zhu, C, Li, F L and Jia, Y W, 2015. The novel technology of inorganic solidified foam with high expansion for preventing coal spontaneous combustion, in Proceedings The Australian Mine Ventilation Conference, pp 121–126 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By Kupper T

Firstly, electric analog models are discus- sed to show fluid streaming conditions. In these models the depth of blast at tuyere level, the height of the bath, the influ- ence of different angles of the furnace zones and the different possibilities of the root of the cohesive zone have been changed. Tests to define the influence at a large blast furnace are given. Secondly, the wear of carbon bricks in the hearth is examined under the influence of gas, slag and pig iron. Oxidation tests in a special scanning microscope with the pos- sibility of heating and gas treatment are shown. Wear mechanisms are discussed fora large blast furnace and proposals for im- provement are given. Finally, the possib- ilities and value of the temperature meas- urement in the hearth block are discussed.

Jan 1, 1981

By D Craw, C Smith, C Martin

The Wangaloa coal mine closed in 1989, and an attempt to grow Pinus radiata on quartz-rich overburden dumps was not successful. The site is currently being rehabilitated with re-profiling and native plant establishment. Plants are being established in a range of substrates that consist of variably disaggregated Tertiary coal measure sediments derived from the mine sequence. This material has low organic matter content (typically <10 %), originating from coal fines or carbonaceous sediment. Substrate samples were collected during December 2003 from a range of sites varying in age, slope, and parent material. Nutrient analysis includes nitrate, ammonia, total N, total P, available P and readily exchangeable base cations. Total nitrogen and phosphorus are low on areas of recently disturbed, quartz-rich overburden, with total N =1200 mg/kg, and total P =200 mg/kg. Background forested areas have total N ranging between 2800 - 3300 mg/kg and total P of 420 - 500 mg/kg. Quartz-rich overburden sites contain available nitrogen levels of less than 6 mg/kg, while background forested areas are generally >20 mg/kg. The soils and water runoff are generally acid, with pH down to three. Water samples have been collected from both ground and surface resources on a monthly basis since December 2003. The main lake on the site had pH of 4.6 in 1999, and this remained relatively unchanged when 850 tonnes of lime were added in 2002. However, the lake pH changed to 6.4 within a one month period in 2004, and has fluctuated since that time.

Jan 1, 2004

The Callie Underground Gold Mine (Callie) is owned by Newmont Asia Pacific and located 531 km north-west of Alice Springs in the Northern Territory. Historically, stopes have been mined utilising a primary and secondary stoping sequence with cemented aggregate fill and rock fill respectively. Current and near-future mining will employ long hole open stoping with rib pillars and rock fill with a paste fill system approved to allow a higher extraction ratio from mid-2011. The Callie rock mass is of good quality with little or no mining difficulties during development and stoping to a depth of 1140 m below surface. Development is currently occurring at depth of 1360 m below surface. Stress damage previously observed only in secondary stope accesses is now observed in development unaffected by stoping stresses. A change in rock mass properties is being experienced with depth, with more pronounced and frequent joint planes. Also, other structures are intersected more commonly, such as lithological boundaries and fault zones. The 'Callie rock factory' mentality that has persisted for years is challenged. This paper covers an appraisal of the stress and ground condition changes at Callie. The appraisal outlines the mine design criterion that was developed and examines the transition from a low stress environment to one where stress damage is observed. Discussion includes a judgement on the rock mass damage observed in development, the dominant geotechnical factors influencing the change in ground conditions, and if a correlation can be made between the observed rock mass damage with stress through the use of numerical modelling.

Nov 25, 2010

Low-grade, porphyry copper type mineralization at the Moonmera prospect is related to the intrusion of a granodiorite porphyry mass into the Upper Permian "Gracemere granodiorite". Significant copper mineraliza- tion appears to be associated with the alteration assemblage quartz-sericite- kaolinite. The ore shell is surrounded by a zone where montmorillonite and kaolinite are in greater abundance and this assemblage is over- lapped, mainly at depth, by potassium feldspar alteration. Secondary biotite is abundant throughout the mineralized zone. Preliminary sulphur isotope results on the sulphide mineralization are compatible with a magmatic origin for the sulphur.

Jan 1, 1974

At the Nikkel og Olivin nickel mine near Narvik, Norway, Outokumpu has been the operator since 1993. The mine was opened in 1989 and in 1992 Outokumpu commenced operations to secure concentrate deliveries to Harjavalta's nickel smelter in Finland. Annual production is about 740 000 tonnes of nickel ore grading 0.5 per cent Ni, about 25 000 tonnes of nickel concentrate and about 2800 tonnes of nickel metal. All production comes from underground operations which makes Nikkel og Olivin AS perhaps the lowest grade underground nickel mine in the world today. Production is currently from one of two orebodies, which is known as the Western orebody. The Eastern orebody was worked out by 1995. During Outokumpu's operational period the Western orebody has been delineated and taken to production. The underground exploration and definition drilling involved about 15 000 in of diamond drilling, which was carried out during a nine-month period. Following this a feasibility study was undertaken and production commenced. Improvements were made to the mining methods. Previously the mine utilised open pit equipment underground and this resulted in an enormous amount of additional tunnelling. Grade control and ore delineation were previously based on sparse diamond drilling and all geological information was processed manually. The improvements included the use of underground sludge drilling to increase the amount of geological information, the of a new computer system for grade control and mine planning, new automated underground longhole drilling equipment and the of underground mining equipment which reduced the size of the drives. These changes produced a marked increase in the efficiency of the underground Mine.

Jan 1, 1996