Search Documents

By C Torrisi, J Andreatidis, M Duffy

BHPÆs Cannington process plant was commissioned in October 1997. The Cannington ore contains high grades of silver, lead and zinc but also contains high levels of fluorine which must be removed to produce a marketable concentrate. As a consequence the plant is more complex than the typical base metal concentrator. Some of the features of the Cannington operation include a single stage autogenous mill, multiple stages of flotation cleaning, two leach circuits, pressure filtration and a paste fill plant. The start-up and achievement of design performance for new lead/zinc operations has traditionally taken much longer than for gold or copper operation and is littered with many tales of woe with feasibility targets often not achieved (Agarwal, Brown and Katrak, 1984; Bulatovic and Wyslouzil, 1999; Leung, Andreatidis, Woodall and Alford, 1996; Sherman, 1999; Ward, 1998).

Jan 1, 2000

By P Chapman, B Moosapoor

The objective of this paper is to present the potential applications of geostatistical analyses in planning CPTu investigations, as well as interpolation of CPTu data. The paper presents a case study of a geostatistical analysis of CPTu data undertaken between 2004 and 2017 for an upstreamraised TSF located in the Goldfields region of Western Australia. An initial model is developed using the 2004, 2009 and 2017 CPTu data. The model is used to predict in situ cone tip resistance (qc) measurements, as the interested primary variable, at the selected locations where 2019 CPTu were undertaken, and the results of the prediction and the actual data are compared.

Jul 1, 2021

Mining of the Martha Hill epithermal gold deposit via open pit methods will excavate a pit to 15 m below sea level. Regular geotechnical evaluations of pit slopes have taken place. Details of the various components of these evaluations, including geological structure, material strength, and groundwater, are covered. Pitwall geological structures are represented clearly on pit floor grade control maps with the dominant sets being steeply dipping strike fractures. Cross cutting shears are common. Material strength is reflected by the oxidation status of the hydrothermally altered host rocks, with weaker material occurring in partially oxidised ground. Regional groundwater is generally high, particularly on the north-eastern side of the pit, where it has been little affected by de-watering. Geological structures appear to control the flow of groundwater in the proximity of pitwalls and require draining by the introduction of horizontal drains. An overview of pit slope design is given. Slopes are designed for overall slope stability, allowing for the occurrence of minor interbench failures.

Jan 1, 1991

This paper describes the new iron and steelmaking process recently commissioned at NZ Steel. Ironsand mined and concentrated at Waikato North head is slurry pumped 18 km to the company's Glenbrook works. Ironmaking includes the direct reduction process pioneered at Glenbrook in the 1970s and a new continuous electric melter. The molten, high carbon pig iron produced is then fed to a vanadium recovery unit and on to the KOBM oxygen steelmaking vessel. Steel is cast into billets or slabs. The new plant, which is the first stage of a fully integrated works at Glenbrook, raises New Zealand Steel's production capacity from 150 000 t/y to 750 000 t/y.

Jan 1, 1986

By S Kodate, Ö Aydan, Y Suda, J Tomiyama

Fracture zones are commonly found in the Earth’s crust. These zones may cause very severe engineering problems. Therefore, the formation and the assessment of the mechanical characteristics of these zones is of great concern for rock engineers. A new double shearing jig was used to study the formation of shear zones in rock under static and impact loading conditions using the device developed by the authors. A series of experiments were undertaken to investigate formation on the formation and characteristics of fracture zones in laboratory. Although actual fracture zones are more complicated, various tests give some insight view of the formation of fracture zones as well as some information on their mechanical behaviour under both dynamic conditions and static conditions. The authors report the outcomes of these experiments and discuss their implications in practice.

Nov 29, 2022

By J-P Franzidis

A technique for determining the recovery of attached particles across the froth phase in flotation that relies on measuring the rate at which bubble-particle aggregates enter the froth is used to investigate the selectivity of attached particles across the froth phase. Combining these measurements with those of other techniques for determining the froth recovery of attached particles provides an insight into the different subprocesses of particle rejection in the froth phase. The results of experiments conducted in a 3 m3 Outokumpu tank cell show that the detachment of particles from aggregates in the froth phase occurs largely at the pulp-froth interface. In particular it is shown that the pulp-froth interface selectively detaches particles from aggregates according to their physical attributes.

Jan 1, 2005

By K G. Fleetwood

This paper proposes an approach to determine the influence of non-ideal detonation characteristics related to the charge diameter, explosive type and confinement conditions on the available shock energy of ANFO and a representative chemically-sensitised (gassed) emulsion. The proposed degrees of non-ideality of the two different blasting agents are indicated by the Gurney ratios, determined from existing cylinder expansion testing data. The influence of the non-ideal detonation properties on blast design and performance are also compared using a series of theoretical, equal powder factor open pit blasting patterns with hole diameters ranging from 102 mm to 270 mm. The non-ideal shock energy factor (NSEF), which is the available shock energy per tonne of blasted material (MJ/t), is used to compare the different blasting patterns as charged with either ANFO or the gassed emulsion of equal charge density (0.85 g/cm3). The intended purpose of this investigation is to provide explosive users with an approach to compare different explosive types or charge diameters in the absence of dedicated non-ideal detonation modelling, which is generally not available to explosives users.The results of the comparisons suggest that at low charge densities, the example gassed emulsion displays a higher velocity of detonation (VOD) than ANFO in smaller charge diameters but similar degrees of non-ideality (based on proposed Gurney ratios). The results also suggest that the confined, non-ideal gassed emulsion VOD at hole diameters greater than 270 mm can be less than ANFO due to the low density effects on the emulsion matrix. The differences in non-ideal detonation properties and Gurney ratios between the ANFO and gassed emulsion resulted in gassed emulsion NSEF values ranging from 15 per cent lower to 65 per cent higher than ANFO for equal powder-factor patterns in blasthole diameters from 102 mm to 270 mm.

Nov 8, 2011

The Golden Valley Volcanic Centre has been recently interpreted as being a combination diatreme breccia pipe and rhyo-dacite flow dome complex of Permo-Carboniferous age that intrudes basement granitoids and sediments of Ordovician-Devonian age. Exceptionally good exposure at the Centre has enabled the relationships between different lithologies to be determined. This, along with petrological studies, has led to a detailed understanding of the geological environment in which the complex formed. Gold, silver and base metal mineralisation have been recently shown to be associated with the Marginal Breccia at the perimeter of the diatreme. Comparisons have been made between the geology and mineralisation in this system and several similar diatremes which also contain gold-base metal sulphide mineralisation.

Jan 1, 1990

By L Xiong, W J Shi, J H. Wei

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Baizhangzi gold deposit is located in the northern North China Craton. The structural and lithological controls on the location and geometry of orebodies were studied through geologic survey, ore spatial configuration analysis and structural analysis. The orebodies of the deposit comprise auriferous quartz-sulfide veins and disseminated gold-bearing sulfides. The auriferous quartz-sulfide veins are dominantly hosted by the NNE- (and NE- and NW-) trending faults, which are subsidiary structures of the regional NNE-trending F2 fault. The subsidiary NNE-trending faults, having sinistral reverse kinematics, are associated with the sinistral reverse kinematics event of the F2 fault, which happened under a regional S–N-oriented compression stress field. The subsidiary NE- and NW-trending faults appear to be compressive and extensional respectively. These NE- (and NW-) trending faults are restricted to the granite intrusion and are associated with a sinistral strike-slip event of the F2 fault, which reactivated under a NW–SE-oriented compression stress field. It makes significant influence on geological evolution and distribution of different ore types that the strike of the F2 fault presents significant transition from NNE- to NE-trending in vertical. The ore-bearing disseminated host rocks, with widespread silicification and pyritisation, distribute in the lower inner contact zone of the granite intrusion, especially in the lower wavelike boundary of granite intrusion.CITATION:Xiong, L, Wei, J H and Shi, W J, 2015. Structural and lithological controls on the location of orebodies in the Baizhangzi lode gold deposit in western Liaoning Province, China, in Proceedings PACRIM 2015 Congress, pp 193–200 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Martin JD, McNicol JH

The electrolytic zinc plant at Port Pirie South Australia, was designed and constructed to treat zinc oxide fume recovered by treatment of lead blast furnace slag in two fuming furnaces, The plant was commissioned in late 1967. The equipment installed and the oper- ating procedures adopted,'are described in some detail.

Jan 1, 1975

By M Boon, M Franklin

This paper outlines the journey of cultural maturation and management system development at the Mt Rawdon (MRO) gold mine from its acquisition by Evolution Mining Limited (Evolution) in late 2011 to 2016.Evolution embarked upon a series of projects that aimed to improve the operational consistency and implementation of change on-site, while leveraging off the existing strengths of the operation. This document describes the gaps that were identified, the processes used to close them, and the resulting cultural change and production outcomes, with a specific focus on how to optimise the culture at any mining operation.MRO had a history of four owners in less than three years when it became a key asset of Evolution. The site leadership team (SLT) decided to influence the culture at MRO by reviewing and upgrading the existing management processes.The first priority was to improve transparency and collaboration at the SLT level, followed by improving competency in project management. The next phase was to strengthen the internal communication using a deliberately designed network of meetings, communication screens and other initiatives. Once there was some traction, the focus moved toward increasing production volume and decreasing cost per unit by improving short-term planning and execution capability. Together with other initiatives, this resulted in improved collaboration between all functions, which in turn netted over 37 per cent mining production uplift.Following solid success, a process of prioritisation and alignment management was implemented. This supported the ‘Mine to Mill one operation’ ideal and allowed the SLT to decide month-by-month what actions were to be prioritised. These priorities incorporated production realities and longer term imperatives of the balanced business plan.Much of this work was completed during a period of declining gold prices and a relentlessly strong Australian dollar, making it difficult to justify spending money on improvement projects. This work proved critical for the operation’s long-term survival.CITATION:Boon, M and Franklin, M, 2016. Improving consistency of delivery at Mt Rawdon Operation, in Proceedings International Mine Management Conference, pp 305-320 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 22, 2016

Refractory gold concentrates and their roasted products have been examined by mineralogical and chemical methods, and the distribution of gold in the tailings after leaching has been Investigated.

Jan 1, 1989

By Howlett P. F, Courtley S

A problem with secondary breaking at one of the mines of Pasminco Mining led to a study of new rock breaking technologies. Many of the techniques being developed had emerged from the thrust in the USA for continuous drill=break excavation. Such approaches to rock breaking highlighted the applicability of what would normally be classified as tunnelling techniques, to the secondary breaking sector - and possibly the reverse. As a direct result of the investigations for suitable technologies, Pasminco Mining supported the development of two improved rock breaking methods specifically targeting secondary breaking, one of which could be applied to continuous excavation.

Jan 1, 1993

The InLine Pressure Jig represents a breakthrough in digging technology Its design incorporates a unique combination of features previously utilised in conventional jig design. In particular, a moveable screen and circular bed are used to excellent effect. However, a major design innovation is the encapsulation of the circular bed within a vessel - allowing the equipment to operate under pressure. This innovation eliminates free water surface, improves the dynamics within the separation layer (crossflow) and provides significant cost savings in the handling of slurries. Recent research results have indicated its capacity to achieve high recoveries and upgrade ratios in the gravity separation of Minerals.

Jan 1, 1997

By Terry G. A B

Before detailed design of Museum Station could commence, a number of factors had to be considered to determine its exact location within the city street pattern, the depth and the dimensions of the underground station. To arrive at a sound con- clusion regarding location, the relationship of the station to probable future city development had also to be considered.

Jan 1, 1981

By Behl S

Flocculation behaviour of six different dolomite samples, four from the Florida mining district, one from Perry, South Georgia and another from New Jersey was examined using polyethylene oxide (PEO) as a flocculant. The samples were similar in chemical composition, however the porosity of the samples from the Florida mining district was higher than the others. FT-IR, adsorption and surface modification by leaching revealed that flocculation was directly related to the presence of isolated hydroxyl groups on the surface. The adsorption mechanism was believed to be hydrogen bonding of the ether oxygen of PEO with isolated -OH sites on the solid.

Jan 1, 1993

By Prosser A. P

A computer simulation is being developed for in-situ leaching of unbroken, Zn-Pb-Ag sulphide ore. Ferric chloride is the selected reagent. Experimental work showed that a diffusion control model of the kinetic aspects was better than a surface chemical reaction control model. Entrapped reactive grains were accessible to reagent in the samples tested. Precipitated sulphur did not seriously hinder the reaction.

Jan 1, 1987

Mining projects frequently fail to meet their financial objectives. A significant area of poor performance lies in the areas of resource estimation, reserve definitions, selective mining and metal accounting. The processes leading to the exploi

Jan 1, 1998

By Redman P. G, McMahon B. K

A simple technique for evaluating the field stress ratio is presented, based on the results of extensometer or convergence tape measure- ments taken in an advancing tunnel. This tech- nique also yields a value for the rock mass modulus, provided Poisson's Ratio is assumed. The results of two case studies are presented illustrating the effectiveness of the method.

Jan 1, 1981

By Yigit E, Royston D, Winborne DA

Semi-bulk concentrates of 45% zinc at 80% recovery have been produced from the McArthur River mineral deposit. Selective leaching of these concentrates to recover lead and a commercial grade zinc concentrate has the potential to increase significantly the recovery of zinc (as zinc concentrate) and lead (as lead metal) over conventional flotation methods producing lead and zinc concentrates.

Jan 1, 1986