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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 X Z. Sun, N Jiang, J H. Zhao, C X. Wang, L Y. Bai

In backfill grouting for underground coalmines, the filling materials strengthen the caving rock and support the overlying strata to reduce surface subsidence. The broken roof strata fail and collapse during mining operations without appropriate supporting measures being taken. It is difficult to perform continuous backfill mining on the working face of such roofs using the existing mining technology. Therefore, in order to solve the above problems, fly ash and mine water are considered as filling materials, and flow characteristics of fly-ash slurry are investigated through laboratory experiments and theoretical analyses. Laws governing the diffusion of fly-ash slurry in the void of caving rock masses and in the void between a caving rock mass and a basic roof are obtained and verified. Based on the results obtained from the above analyses and field conditions at the Zhaoguan coalmine, Shandong Province, China, a cave backfill grouting system of the hauling pipeline is developed and successfully tested at the 1703 working face. The results demonstrate that a filling rate of 43.46 per cent is achieved, and the surface subsidence coefficient of the grouting process is found to be 0.475. Compared to the total caving method, the proposed system is found to achieve a reduction rate of 40.63 per cent. This effectively helps in lowering the value of the surface subsidence coefficient. Fly ash and mine water, considered as primary materials in this study, also play a significant role in improving the air quality and water environment.

Nov 29, 2022

Edie Creek is located in the Morobe Goldfield about 17km by road from Wau in the Morobe Province of Papua New Guinea (PNG). Four distinct periods of mining development have occurred since discovery of rich alluvials in 1926. During the two years following discovery, individual expat-riate miners with gangs of native labourers mining rich alluvial gravels dominated the field. After the discov-ery of hardrock mineralisation in 1927, companies accumulated leases and devel-oped extensive underground mines and mechanical processing plants at Day Dawn Mine and Edie Creek/Karuka Mine between 1929 and 1942. After the Second World War, the underground operations were not re-opened, and mining activ-ities mostly concentrated on working alluvial and eluvial deposits. From 1962 onwards, Papua New Guinean miners became increasing producers as company activities declined. In 1990, Edie Creek Mining Company Pty Limited, a joint venture company involving Wau landowner groups commenced operations on New Guinea Goldfield's leases. It currently mines by open pit methods, rich quartz stringers and is invest-igating the open pitting of the Edie Creek/Karuka underground workings.This paper describes the mining and processing techniques employed during the various phases of develop-ment at Edie Creek in the past 70 years. The problems and hardships of operating on a new and remote goldfield are outlined.Abstract

Jan 1, 1994

By G Balog, T Ormerod, D Cox

This paper discusses the methods utilised by the technical team to identify and quantify the SLC risk factors, the modifications to mine design and scheduling, and the changes to the planned risk management practices. The paper also describes the future work currently planned by the OZ Minerals technical team to quantify the various risk factors in terms of space, time and magnitude. This may better inform the future mining practices within not only the Carrapateena province but also the wider Gawler Craton.

Mar 15, 2021

By J Pan

In this paper, the technology of producing fluxed pellets by using hydrated lime as binder instead of bentonite was carried out. The properties of the two types green balls (0.8 per cent bentonite and 2.0 per cent hydrated lime) were as follows: drop numbers of 4.8 - 5.0 times/0.5 m, compressive strength of 19.7 - 24.2 N/pellet and thermal shock temperature of 280° - 385°, respectively, under the same conditions of 1.5 per cent coke, 1.45 basicity and balling at 8.5 per cent moisture for 13 min in disc pelletiser. Comparing with bentonite as binder, the compressive strength of fired pellets with hydrated lime is elevated by 13.8 per cent and climbs up to 3113 N/pellet under the following conditions: preheating at 1050°C for ten minutes and fi ring at 1300°C for 15 min. In the mean time, the hydrated lime also improves the metallurgical performance of fired pellets. The reduction index was enhanced from 68.6 - 70.6 per cent, RDI+3.15+ increased from 90.1 to 98.8 per cent and reduction swelling index dropped from 22.4 - 7.4 per cent, respectively. The mineral compositions and microstructure of fi red pellets shows that the fired pellets containing 2.0 per cent possess more calcium ferrite and magnesium ferrite and compact microstructure, leading to the higher compressive strength.

Jul 11, 2011

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 S P. Suthers, J M. F Clout, J J. Campbe

An advanced technique for modelling hydrocyclone separation performance has been developed. This technique is based on the combined modelling of hydrocycloning parameters and ævirtualÆ iron ore feed. The virtual feed modelling was performed using a novel (in-house) software package called æRecognitionÆ, which uses data from optical image analysis to classify the particles in certain size fractions according to total iron content and calculates data for every grade class. These data include the average mineral composition and density of every liberation class in every size fraction. This information about every size fraction, representing the ævirtual feedÆ, was input to the mineral processing modelling package USIM PAC. The hydrocycloning process was then modelled for this virtual feed using the Plitt hydrocyclone model. Empirical calibration coefficients for the hydrocyclone model were calculated using an optimisation procedure in Excel. Pilot-scale hydrocyclone beneficiation experiments were performed on an iron ore blend, using different hydrocyclone pressures and per cent solids in the feed pulp. These experiments were modelled and the modelling results were compared with the experimental results. The new modelling approach enables prediction of the recovery of each mineral in the products, calculation of the total iron grade and recovery, and optimisation of iron ore beneficiation using hydrocyclones.

Jan 1, 2005

By E Y. Baafi

Artisanal and small-scale gold mining (ASSM) offers lucrative employment opportunities to the locals of most developing countries. The major drawback of ASSM is its adverse impacts on the environment resulting from improper mining and processing techniques. Papua New Guinea (PNG) has very active ASSM activities. The artisanal and small-scale gold mining in PNG provide employment at local and national levels and the sector is an important source for inflow of foreign exchange into rural communities. However, small-scale mining activities are associated with sensitive health and environmental issues. The process of recovering gold by retorting and heating the amalgam over an open fire is a dangerous health practice. This paper discusses artisanal and small-scale gold mining operations in PNG and their impacts on the local environment.

Jan 1, 2008

By Q Zhou, H Nordberg, W Wang-Geissler

Efficiently controlling foam/froth within mineral processing continues to pose a challenge to the mining sector. The foaming characteristics of aqueous solutions for two-phase systems of air/liquid are well-studied with theories and mechanisms proposed to describe and predict foam formation and stability. The types and structures of reagents that either promote or prevent foaming/froth formation and stability are well-defined in these studies and practiced across various applications. Three-phase systems of air/liquid/solid, such as froth from mineral slurries, however, pose a challenge with the presence of a large quantity of relatively fine mineral particles. Theories and mechanisms that rationalise the effects of chemical additives as a defoamer or foaming agent in aqueous can be applied as a general rule, but do not provide the most effective solution for mineral slurry systems. Silicone-based defoamers, particularly their O/W emulsions, have been widely and successfully used at various stages of mineral processing to efficiently control the mineral slurry foaming properties. However, their foaming control ability could be significantly impacted by different processing aids used during the upstream process. In a zinc-rich mineral system, a silicone-based defoamer starts losing the properties necessary to effectively control foaming in the leaching circuit when throughput is increased. In this study, the synergistic defoaming/anti-foaming effects from surfactants and silicone-based defoamers are discussed to effectively control foaming/froth in the zinc leaching circuit, even with lower total defoamer dosage. Improvements during mineral processing can also lead to a cleaner mineral grade by reducing waste.

Aug 24, 2022

By Letz H

An investigation of earthquake hazard in Papua New Guinea (PNG) by a yearly extreme magnitude method using the magnitude 7 earthquake record since 1900 shows that the Bougain-ville Island seismic zone is by far the most active, followed by the New Britain and northern mainland PNG regions. Return period for magnitude 7.0 earthquakes occurring in normalized 10,000km2 areas of the Bougainville Island, New Britain, Huon, West Bismarck, North Sepik and Ramu seismic zones is 37, 60, 81, 88, 125 and 125 years respectively. These areas are much more active than the California Seismic Zone 4 region including the San Andreas Fault, which has a normalized magnitude 7.0 return period of 299 years, calcul-ated here by the same method.Only southern PNG, including the Papuan Fold Belt and most of the Bismarck Sea, are less active than California Zone 4. The Papuan Fold Belt is only marginally less active than California Zone 4, but more active than the State of California taken as a whole.

Jan 1, 1994

By L Ding, B Xu, C Wang

In this paper, we introduce the term ‘LJC’ to refer to the LJC Automatic Magnetic Flotation Separator, which is an advanced technology developed by Longi Magnet, integrating various techniques such as hydro separation, magnetic flocculation, and magnetic columns. This technology combines gravity, hydro separation, and magnetic separation to achieve efficient and reliable separation processes. With its low maintenance requirements and high reliability, the LJC technology has proven to be effective in magnetite processing. The LJC technology offers two primary benefits when compared to traditional magnetic drum separators. Firstly, it can enhance the quality of the targeted or improved concentrate at a coarser product size by minimising the carryover of gangue minerals into the concentrate. Secondly, it can significantly improve the concentrate quality (eg achieving >67 per cent Fe) while maintaining similar liberation size and mass yield. In China, this technology has been widely adopted in magnetite processing, replacing traditional magnetic drum separators and fines flotation in the final stage of the process. Through collaboration with a magnetite producer in Western Australia, Longi Magnet successfully implemented the next-generation LJC Automatic Magnetic Flotation Separator to replace the original stage 3 magnetic drum separators. The application of the LJC technology resulted in an increase in product P80 from 32 μm to 43.1 μm, while maintaining a final concentrate grade of 65 per cent Fe. Additionally, the power consumption, measured in kWh per tonne of concentrate, was reduced by 10 per cent. By eliminating the bottleneck caused by the requirement of a coarser liberation size to achieve the desired concentrate grade, the plant’s throughput was increased by significantly. The LJC technology has demonstrated its ability to reduce the carbon footprint, improve concentrate grade and enhance mass recovery, offering an alternative solution for magnetite processing. The high-grade magnetite produced by the LJC technology is particularly suitable as a raw material for Directed Reduction Iron and green steel production. This paper introduces the principles of the LJC Automatic Magnetic Flotation Separator and provides details of its application in a magnetite operation in Western Australia.

Sep 18, 2023

By O Otgonbayar, B Bayarmaa, D Batbyamba, S Amar-Amgalan, K H. Natsagdorj, J Nomin-Erdene, B Boldkhuu, T S. Sainzaya

The Argyle deposit in the Kimberley region of Western Australia was the world’s largest accumulation of natural diamonds. Following its discovery in 1979, the mining of associated alluvial diamonds commenced in 1983, followed by the pipe in late 1985. Over the life of the mine to its closure in November 2020, Argyle produced approximately 900 million carats of diamonds. Argyle diamonds are distinctive in having a predominance of brown colours and rare highly-prized pink diamonds, which are a signature of the deposit. The 3D geological model developed from mining and deep drilling shows that Argyle is a composite pipe formed by the coalescence of several steep-sided diatremes, each with their own feeder zones at depth, that were erupted along a NNE-trending fault. The ~1.2 Ga Argyle pipe is comprised of diamondiferous olivine lamproite volcaniclastic rocks and intruded by sparse olivine lamproite dykes. The volcaniclastic rocks are predominantly comprised of unconsolidated quartz-rich lapilli and coarse ash deposits formed by numerous phreatomagmatic eruptions of olivine lamproite magma through Mesoproterozoic water-rich sands and silts. Post-emplacement deformation has tilted the orebody 30° to the north and regional strike-slip faulting has offset, segmented, and elongated the orebody. Recent significant modifications of the geological model resulted from underground block cave operations, producing several critical lessons learnt. Diamond grade and quality reconciliation issues warranted a geological investigation which resulted in the recognition of new volcaniclastic olivine lamproite domains with a broad range of diamond grades, including some very high-grade units. The new lamproite domains had a significant effect on the block cave mining and resultant recovery of diamonds. The new findings enable a more coherent and detailed geological understanding of the volcanic emplacement and paragenetic sequence of the Argyle AK1 pipe. Structural modelling of the deposit also played a major role in the block cave mining tonnage recoveries and daily operations. The re-examination of the geology of the Argyle pipe and the results of this new information reinforces the need for ongoing robust geological work both in the early stages of mining a deposit and continued during the life of the mine.

Mar 22, 2022

With the advent of COAG reforms in the late 1990s requiring full commercial return from æpublic infrastructureÆ, and the tightening regulatory compliance for any project that involves the development or modification of any natural resource, it has become increasingly difficult for the private sector to contemplate development and/or ownership of new large-scale water supply infrastructure. The hurdles that must be overcome often seem insurmountable even before a detailed understanding of the project challenges can be developed. Australia has prospered over the last 50 years in an environment where regional development, including mining, has been encouraged by high commodity prices, a well-trained and available labour force and abundant spare capacity in the necessary infrastructure, in particular rail, power and water. Unless future infrastructure is created in advance of, or closely following, demand, this prosperity may be in jeopardy. This paper presents a snapshot of todayÆs project development challenges, and with reference to some recent case histories, argues that owing to their unique background, culture and status, water utility government owned corporations (GOCs) are well-suited to fulfilling the demand for new water infrastructure.

Jan 1, 2006

New Zealand China Clays operata a plant at Matauri Bay, Northland for the benefaction of hallosite clay. Production is several thousand tonnes per year of which about ten per cent per year is supplied to an expanding export market.

Jan 1, 1978

Ranger Uranium Mines (RUM) operates an open cut located in the Top End of the North- ern Territory. Strict environmental controls govern all operations and the water management requirements have the greatest impact on mine planning. The two main goals of planning are to provide mill feed and to mine sufficient suitable quality waste rock for ongoing con- struction of the tailings dam. Early planning concentrated on staged development of the pit to provide access to as much ore as possible for a given amount of development. All waste was considered to be suitable construction material. Grade control of crusher feed was the main problem in planning, as wide vari- ations occur in ore grade over relatively short distances. Water management for the site ope- rates a no release' system for contaminated waters. Design storage has proven inadequate, and the open cut has been used as the extra storage. As construction of future stages of the tailings dam requires non-mineralised rock materials which meet specific quality criteria, the mine has had to re-examine long term plan- ning and pit development strategies. This has entailed the collection of much data not re- quired under normal mining conditions, such as the assaying of waste drill core. The overall impact on mine planning of the environmental regulations has been to alter the philosophy of earlier planning, making it necessary to create a new strategy for pit development with

Jan 1, 1984

Using a new type of laser surveying instrument named Particle Dynamics Analyser (PDA), the distributions of the radial and axial components of the mean velocity, the size and the concentration of solid particles at selected positions within a transparent hydrocyclone were directly measured out for the first time, from which profiles of the flow field of solid particles were obtained. And some new points were put forward such as the locus of zero vertical velocity (LZVV) of solid particles was not the same as that of liquid, and some particles in inner helical flow could also be separated. The results are of great significance to farther ascertain the separation principle of hydrocyclones and improve the separation efficiency.

Jan 1, 1993

The MIMDAS geophysical data acquisition system developed and tested by the former MIM Exploration Pty Ltd (MIMEX) is now commercially available worldwide through Geophysical Resources and Services Pty Ltd (GRS). The system implements several new features in its design that give it significant advantages over conventional systems and allows for new approaches to electrical exploration. In particular, the achievable signal to noise levels permit exploration to depths once thought beyond the range of electrical exploration. The flexible multi-channel configuration lends itself to truly 3D surveys in the style of modern seismic techniques. Each of these aspects is illustrated with a number of case histories from both Australia and South America.

Jan 1, 2004

By Kellett KR

Gold Mining at the Lancefield Mine was commenced initially in 1897 and continued intermittently through to 1956 when rising costs and mine cave-in forced closure. The mine was redeveloped in 1981 and a new-oxide treatment plant commissioned, followed by a new refractory treatment plant in late 1982. Both these treatment plants are located within the Windarra Nickel Project plant area.The refractory ore is processed by fluidised bed roasting of flotation concentrates. This is carried out in two series connected reactors to maximise arsenic and sulphur eliminations and to minimise reagent consumption. For gold recovery the zinc precipitation process was initially used, to be later replaced by carbon-in-pulp.

Jan 1, 1984

By M McDonald

KiwiRail has a goal of significantly improving passenger rail services to west Auckland, as part of its DART (Developing Auckland’s Rail Transport) suite of projects. The New Lynn Rail Trench (NLRT) project was a significant component of this work. The NLRT project facilitates essential doubletracking of the Western Auckland line, and provides a new commuter transportation hub within a busy town centre.The 1.5 km stretch of track through the New Lynn town centre has bisected the township for over 80 years. Double-tracking the line provided the opportunity to grade-separate road and rail, which would help to re-connect both sides of the township and enhance public amenity and safety.KiwiRail employed an Early Contractor Involvement (ECI) procurement model engaging a consortium comprising Fletcher Construction, Beca Infrastructure and Synergine to develop a Design and Construct solution.With weak soil conditions and high groundwater levels, a diaphragm wall construction method to form the trench walls was selected as the best solution. Further challenges to construction included working within a narrow rail corridor constrained by buildings along much of the boundary, and a requirement to keep the existing line open for rail services. Detailed construction planning was required to ensure rail and construction safety in a constrained space whilst building the trench walls, propping these walls during excavation, and constructing the base slab in the most efficient way possible.This paper will detail the geotechnical conditions and the additional constraints that made this rail trench a challenging structure to design. It will also describe the fi nal design and construction methodologies that were employed, that allowed very successful completion of the project.Additionally, this paper will review the design and construction lessons applicable to the current Victoria Park Tunnel project, and indeed for all future cut and cover tunnel projects in the Auckland isthmus.

Mar 8, 2011

Accident control has been a pre occupation of progressive industrial and mining companies for many years but few have attempted more than direct injury control. In recent years, particularly in North America, analyses of accident costs have shown that material damage resulting from accidents is usually of greater economic significance than injuries and this has led to the concept of loss control. Loss control is an attempt to take the emphasis off injury prevention and to concentrate on the basic factors which affect both the health of the individual and of the company. The deterrent to greater acceptance of this philosophy has been the apparent diffi- culties of implementing a loss control programme but Associated Minerals Consolidated Limited has adopted a simple approach. It has had a minimum disturbing effect on normal operations because existing systems have been modified to provide the new information required. It is suggested that the programme outlined is applicable to other mining ventures and is a practical method of providing benefits for both the company and its employees.

Jan 1, 1975