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The "Line of Lade", a generic term by which the great Broken Hill orebodies are collectively known, lies in the County of Yancowinna, New South Wales (NSW) at the south eastern extrenity of the Barrier Ranges. As the township of Broken Hill grew to a city (incidentally it was officially named Willyama but by exerting an enterprising community independence which is still evident today it outplayed officialdom and retained its descriptive name), two major areas of population developed, Broken Hill and South Broken Hill. These two main civic divisions are respectively north west and south east of their dividing line, the surface expression of the orebody. See Fig. 1. The border between the States of NSW and South Australia (SA) is drawn along longitude 1410 East whilst the city of Broken hill's official longitude is 1410 28' 14" East which means it is only 50 km from this political boundary. A latitude of 310 57' 03" South contributes to the harsh climate of high summer temperatures which is not mollified by any significant increase in altitude for Broken Hill is only 300 m above sea level.

Jan 1, 1983

Around no subject of technical )uterest have prejudice and wrong-thinking in the past so wrapped a web of obscurity as that of the corrosion of metals.It is a matter which has primarily concerned the engineer, but the paucity of his training in chemistry and electrochemistry has been the stumbling block to a better understanding of its mechanism.Now that the more important conditions controlling corrosion have been scientifically.established, it can be seen that, with the exception of but a few of the minor points, the electrochemical laws enunciated by Faraday, Helmholtz; Nernst, and others, are sufficient to include all the facts of the process.The word corrosion (derived from the Latin rodere-to gnaw) is so often wrongly applied that a definition at this stage would be useful. As now understood, it means the dispersion and waste of the useful solid metal by conversion into a useless compound which mayor may not be retained on or near the metal remaining.Commonly the presence of these compounds is regarded as evidence of corrosion, but the converse is not necessarily true; the lack of visible corrosion products on a clean surface of metal is no criterion of the absence of this change. It may be difficult to prove that the erosion of such a surface has been caused by chemical and not by mechanical effects alone.

Jan 1, 1932

Infrastructure is defined as all those parts of a mining development which are not directly concerned with mining and mineral processing. Infrastructure is of significant and growing importance in the overall develop- ment of mines, and the costs could be critical in determining the viability of a project. Prior to_project authorisation, feasibility studies are required, often in considerable detail, to determine costs with adequate reliability. It is necessary that the Engineer should be adequately briefed for carrying out these studies and that good liaison and communication with the Owner be maintained. Methods, costs, order of accuracy, and some special requirements of these studies are discussed. After project authorisation, rapid im- plementation of the proposals is generally desired. A suggested organisation and method for this implementation is presented and dis- cussed. Comments on fees, and particular points in the relationship between Owner and Consulting Engineer are given. Particular reference is made to differences in conditions compared with public works projects. Realistic attitudes of mind towards environmental matters, industrial relations, and contractual relationships are advocated.

Jan 1, 1974

By Sinha DK

Coal Mining in India had been confined in the past primarily to two or three coalfields. Unscientific mining has led to huge degradation of land including massive subsidence of strata and disturbances of water tables to a wide extent. This has caused problems not only in flooding of mines from surface water but also in further planning of the surface drainage for current mining activities. Now, therefore, surface hydrology and land-use potentialities of the area have been endangered inflicting severe damage to the overall environment and ecology of the area. The paper Discusses certain investigative aspects of the problems highlighted as above in one of the coalfields, and encompasses mainly the following areas : 1) Quantitative estimation of the damage already done to the natural surface drainage system. For this purpose damage to topography and drainage for the last fifty years have been made out through the aerial photographs and topographic map sheets 2) Analysis and comparison of different states of such photographs are carried through to indicate the extent of damage to the hydrological conditions inducing undesirable changes in its land-use pattern. Based on the analysis, concrete suggestions are made to restore the water drainage system which will be most suitable for future mining in the area containing high grade coal. The design and planning of the drainage system is based on the total system approach including the cost benefit analysis as well as hydrological considerations.

Jan 1, 1988

By S Latchireddi

Close circuiting autogenous and semi-autogenous mills is anenergy efficient way of grinding and a number of operations haveutilised this in the design of their comminution circuits. Owing tothe large flow of slurry through the mill that results fromoperating this way the grates and pulp lifters have to be designedto cope. However, the literature has little or no information onhow grate and pulp lifter size and design are related to theirability to remove slurry from the mill. Over the last few years theJKMRC has been researching this area and has developedrelationships between grate/pulp lifter design and flowratecapacity. At the same time it has determined the major causes ofpulp lifter inefficiency and a solution to preventing thisinefficiency (the Twin Chamber Pulp Lifter). This paperdescribes the models that have been developed through thisprogram and uses industrial scale data to illustrate their accuracy.Results from the industrial trials of the Twin Chamber PulpLifter are also presented.

Jan 1, 2001

The paper gives details of the performance of a 6-ft. by 6-ft. grate discharge ball mill which was converted into a rod mill of the overflow type and then into a grate discharge rod mill. Proposals for further alterations are outlined.INTRODUCTIONThe mill of King Island Scheelite (1947) Limited recovers scheelite by gravity methods.Crushed ore at the rate of 34 tons per hour is divided between two mills. (6 ft. by 6 ft. and 8 ft. by 6 ft. respectively), the mill discharges being pumped to a common distributor which feeds seven Hummer Screens. Each screen has three 4-ft. by 2-ft. Ton-cap sections and repulping compartments are provided. The screen oversize is returned to the mills whilst the screen undersize is finished grinding section product. A third (6 ft. by 6 ft.) mill regrinding the coarser table tailings also discharges into the common Hummer Screen Distributor.The screen undersize is pumped to a bowl classifier which separates at 200 mesh. The bowl classifier sands are treated on tables whilst the bowl classifier overflow, after thickening, is treated in the slime plant by flotation. The flotation concentrate is further concentrated on vanners and slime tables.A recovery of 80 per cent. is possible by tabling whereas only 50 per cent can be recovered in the slime section. The object of comminution is, therefore, to reduce all the new feed to less than a certain mesh (22 mesh Tyler) with the production of a minimum quantity of minus 200 mesh material. cheelite is, a very friable heavy mineral (Sp.Gr. 6'0) and is therefore susceptible to overgrinding. For the evaluation of grinding performance it is hence advisable...

Jan 1, 1955

Projections of metal requirements for Japan and the United States indicate growing competit- ion for Australia's mineral output and a critical need for continuing discovery of new reserves. These projections may be modified by economic, social and political controls - the most import- ant factor probably being a shortage and the high cost of risk and development capital. Changing ownership patterns toward joint ventures and increased state participation are anticipated. New developments in global tectonics and metallogeny delineate favourable zones for ex- ploration and permit establishment of priority search areas even in regions of poorly known geology. Declining ore grades and special character- istics to meet technological requirements may modify identification and evaluation criteria. A broad approach considering all environments of concentration within the geochemical cycle is re- quired within any metallogenic province. The exploration geologist must be able to integrate geological theory, mining technology and financial analysis to establish well defined exploration objectives, in terms of economic and geologic models, in concept-oriented programmes.

Jan 1, 1973

The environmental and social responsibilities of the mining industry have long been recognized by the industry itself, but during the past decade it became one of the main targets for the more radical members of the community. This came as something of a shock to an industry which had always considered that it had acted responsibly within the standards of the day. As far back as early 1968, the Australian Min- ing Industry Council (AMIC) was clipping from newspapers the odd letter written by environmen- talists and critics of mining activities. In those days every such letter was carefully studied to ensure that AMIC, if not having the answers, at least had an understanding of the types of argu- ments then starting to be used against mining activity and in favour of environmental preserva- tion. Within 18 months, the infrequent letter to the editor had become a flood of such letters and feature articles, and the environmentalists' attack on mining activities had been launched in all its Vehemence.

Jan 1, 1978

Mineral policy is now generally regarded as a function reserved to government. Government is reponsible for the economic health and progress of nations, and must therefore interest itself in minerals as a basic national resource. Government should therefore identify objectives which it sees as suitable and necessary for the mineral industry so that the industry can play its part in achieving national goals. It should provide the legislative framework and policy guidelines to enable these objectives to be achieved. The essential objective of a national mineral policy should be rational development of the nation's minerals resources. To achieve this, it need not be too formal; broad guidelines are enough. But it must be dynamic, to keep pace with the changing circumstances of the mineral industry in the world scene and the changing requirements of government. It should be flexible, recognising that there is no such thing as a "typical" mineral deposit; above all it should represent the outcome of a continuing dialogue between government and industry. Both government policy and corporate planning need to be formulated on the practical understanding of the potential economic value of the mineral sector and what it can contribute to the nation's prosperity. There needs to be a common understanding of the wide range of the costs of risks that may arise through the exploration and development stages and of the uncertainties affecting ventures at the production stage. There needs to be a common understanding that the size and importance of the mineral sector is determined in the long run by the level of investment in exploration. The development of a continuing understanding between government and industry should lead to the formulation of ground rules which ensure the continuance of a strong industry able to adapt to the changing world scene and make its contribution to national growth and wellbeing.

Jan 1, 1986

Conventional blasthole sampling for grade control has acquired an extremely bad reputation for the last 50 years. The introduction of many sources of bias is a structural reality. Delimitation biases are devastating. Extraction biases are of great concern as well. Weighting biases aggravate an already bad situation. Furthermore, preparation biases are many. Some of these biases are due to the type of drilling machine that is used and are nearly unsolvable. Some of these biases are due to the sampling tools that are used and often unsatisfactory. Attempts to automate blasthole sampling at the drilling site have failed, not because it cannot be done, but mainly because it interferes with drilling productivity. As a result the miner most often rejects the idea after a few weeks of practice. Manual sampling of blasthole piles is a disaster for many reasons; some are related to the methodology, some to the selected sampling protocol, some to the training of operators, some to limited manpower available, and some to limited supervision. Furthermore, with blasthole sampling a time logistic problem is unsolvable as the miner wants the ore grade control geologist to make up his mind within two or three days at most; as a result not enough time is allowed for samplers, preparation facilities, laboratory, and resources department to perform a good job as everyone is working under unreasonable pressure. The economic impact of poor blasthole sampling for grade control has been vastly underestimated by mining companies. The resulting ore grade misclassification is responsible for severe reconciliation problems and massive financial losses every year. This paper suggests areas along this grim scenario where things can be greatly improved; however it is clear that too many problems are unsolvable. An alternative using reverse circulation drilling for grade control is suggested. A thorough analysis of the respective advantages and disadvantages for blasthole and reverse circulation drilling for grade control is presented in this paper.

Jan 1, 2008

By A Flatten, F Reusch

Recent advances in the disciplines involved in simulating large mining operations provide increasingly precise and accurate methods for the study of cave mechanics; however, in large regional-scale models, hydrological aspects are often neglected or studied independently from the mechanical problem. There exists a great demand for a unified approach to study and simulate both the mechanical and hydrological phenomena that allows for a more detailed understanding of the effects of groundwater flow, dewatering and the impact on block cave mining operations.This paper presents a numerical framework that combines three-dimensional regional-scale hydrological simulation techniques for groundwater flow, together with non-linear continuum–discontinuum rock mechanics models, provides such a unified modelling approach. The underlying simulation technique is based on a coupled parallel solution formulation adopting single-phase fluid flow formulations into a discontinuous, strain softening and dilatant finite element model. This approach is adopted for the presented case study of a realistic block caving example in a simplified unidirectional coupling formulation, to investigate the effects of the mechanical analysis on the hydrological response. Here, particular emphasis is on the non-linear coupling of the deformable and strain-softening solid skeleton and fluid phase; eg the change of hydraulic properties with evolution of damage in the rock mass and large-to-intermediate scale structures due to ongoing caving operations. The importance of discontinuum structures is discussed, as mining-induced fault reactivation significantly influences the hydrological response.CITATION:Flatten, A, Reusch, F and Beck, D, 2016. The application of hydromechanical mine-scale modelling for large block caving operations, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 341–348 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

Large deposits present computational challenges to todayÆs commercial orebody modelling systems that are based on conventional block models. We describe a system that is specifically engineered to model and visualise large deposits. Central to the system is linear octree encoding of conventional block models and real-time conversion of three-dimensional (3D) meshes to linear octrees. We provide both methodological treatment and practical experience in implementing such a system. A commercial implementation is also presented to demonstrate the validity of the approach.

Sep 26, 2011

By P A. Grossman, J H. Rubinstein, M Brazil

The installation of truck turntables at above-ground crushers has the potential to yield gains in efficiency and productivity by eliminating the need for the trucks to turn around and reverse up to the crusher to dump their loads. The benefits include savings in time, fuel consumption and tyre wear. In addition, having a smaller area near the crushers dedicated to manoeuvring the trucks can be a significant benefit at some sites. Safety is also enhanced using turntables.This paper describes a project with the Australian Turntable Company to develop software that generates near-optimal layouts for the paths taken by the trucks in the vicinity of the crushers when turntables are present or absent. The geometry of the paths is constrained by the turning radius of the trucks and by the boundary of the manoeuvring area. The software quantifies the benefit of installing turntables by generating a design for paths with turntables and comparing it with the layout in current or planned use by the mining company. Through the use of this software tool, a mining company can readily assess the benefits of using turntables at their site.CITATION:Brazil, M, Grossman, P A, Rubinstein, J H and Thomas, D A, 2014. Demonstrating efficiency gains from installing truck turntables at crushers, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 259–266 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By T A. Carter

In 2010 Agnew Gold Mine (AGM) struggled to produce the required tonnages from its stopes. The longhole rises used to create void in stopes were unreliable and often failed to gain the designed rise height. The number of firings per stope was having an adverse impact on the ground conditions at the stope brows, impeding stope productivity.Through practical experimentation with longhole drill rigs, box hole rigs and development drill rigs as well as trialling new methods in conjunction with reviewing drill hole data, drill hole accuracy was observed to be an issue on-site. Innovative dragging methods such as the reverse drag, combined with a slope instead of a vertical face on the rear of stopes, have improved dragging and a reduction of firings per stope, enabling larger production blasts.The methods trialled and subsequently implemented at AGM have facilitated the mine achieving budgeted targets for six consecutive quarters. This paper documents the use of these methods in a key lode of AGM’s operations to improve drill and blast practices in order to achieve production targets.CITATION:Carter, T A, 2014. Improving production drilling and blasting in the Kim South orebody at Agnew Gold Mine, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 251–258 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

By S Thomas, S Ricketts, R Hassell

Northern Star Resources (NSR) operates several operations utilising narrow vein stoping operations in the Kundana area. Stope dilution performance is variable across these operations, with unplanned dilution reducing individual stope economic viability, increasing risk to personnel and machinery operating in and around the stope and delaying the overall stoping sequence. Technical investigations were undertaken to objectively understand the variables which had the largest impact on stope performance and then use the findings to help develop mining strategies to reduce dilution. A stope reconciliation process was developed to compile key stope performance information such as stope design parameters, geotechnical and drill and blast factors. These were compared against the measured dilution. Production targets necessitated a high turnover of stopes in the operations, and hence a requirement for an expeditious process and mine design software with automated tools. The output of these results, together with numerical variables from geological, geotechnical and drill and blast data were analysed via multivariate regression. The analysis identified the factors with the greatest influence over stope dilution, and a forecast model was consequently created. Confidence was gained in the model when the subsequent stopes performed in line with prediction. Different drill and blast designs were subsequently trialled and found to reduce dilution. The model was then updated with the new practices, facilitating further regression analysis to identify revised key controlling factors. The subsequent production results however, displayed a poor correlation with the prediction from the revised model. Inconsistencies in drill and blast designs and execution were identified as key factors in the dilution performance. This was an important finding as the correct implementation of the design is critical and this has become a key focus for future stoping. Overall the technique presents an objective process to identify causal factors of stope dilution resulting in improved economic metrics for stope production. The process will be applied to other similar Northern Star operations.

Mar 15, 2021

By P Scott

Kaltim Prima Coal, an open cut coal mine located in Sangatta, East Kalimantan, Indonesia, operates two deep pits and two shallow pits with a truck and shovel operation. KPC produced 17 Mt of coal in 2002 by removing 120 Mbcm overburden. Geochemical investigations have indicated 20 per cent of total waste rock is potentially acid forming; ie it has the potential to create acid mine drainage (AMD). In the early years of the KPC operation, the presence of AMD had been observed in the mined out areas and in the waste rock dumps as a result of sulfidic waste rock exposure. A strategy for management of AMD from waste rock was implemented involving: sampling, analysis, modelling, selective handling and validation of final dump covers. Samples of the waste rock lithologies are collected from exploration drill holes for geochemical analysis to determine their acid generating potential. The geochemical database is used to develop the waste rock model for the life of mine pit areas. The acid forming and non-acid forming waste rock is delineated for each mining bench area for selective handling and placement within the waste rock dump during the operational stage. Each mining bench is sampled and assessed to validate the model predictions. The final dump cover is sampled to meet strict Quality Assurance requirements to ensure non-acid forming waste material is used in the outer cover of the dump. The geochemical investigation of the waste rock is integrated with mine planning to design and construct the waste rock dump to minimise the risk of generating acid. This process links the exploration stage, operation stage, and rehabilitation stage for each Pit area. The paper briefly reports the waste rock characterisation, waste modelling and strategies used for management of acid drainage by KPC.

Jan 1, 2003

Recent data contributions to New Zealand Mesozoic terrane geology confirm the consensus interpretation that New Zealand grew by the progressive addition of material by plutonic and accretionary processes along the Gondwana margin. The data also (1) emphasise the discontinuous but inter-related nature of these processes of continental growth, (2) better establish a direct Gondwana correlation of the Western Province and probable Gondwana provenance of at least some of the Eastern Province, (3) suggest specific times and places when passive or strike-slip rather than subduction regimes are recorded along the south Gondwana margin, and (4) potentially lead to interpretations emphasising parautochthonous rather than far- travelled relationships between many New Zealand terranes.

Jan 1, 1995

In late 1987 it was recognised that column flotation might have potential for improving the grade of the zinc concentrate produced at Pasminco's South Mine in Broken Hill. Intermittent test work was carried out during 1988 using a 90 mm diameter by 6 m high perspex column, built and initially operated by staff from CRA Advanced Technical Development. This column was found to have insufficient retention time so, during the first half of 1989, Pasminco constructed and installed a 200 mm diameter unit of the same height. Extensive testwork was carried out using this column during the latter half of 1989 and early 1990. It was clear from the results that a grade improvement of between 1 and 2 per cent (absolute) would be achievable. The effect of column cleaning on overall recovery was not established with the same degree of confidence, so the proposed new circuit is to include one of the existing banks of OK8 cleaner cells as a scavenger on column tailings. The test work provided sufficient data for preliminary design work to begin in May 1990 and commissioning of full scale zinc cleaner columns is planned for mid 1991. This paper summarizes the results and describes some of the experiences with column flotation at the Pasminco South Mine.

Jan 1, 1991

By J Galvin

This paper addresses the actions of the Australian mining industry, its regulators and educational providers towards ensuring that a pool of competent mine managers is maintained in Australia and that mine management remains a desirable career path for future mining professionals. The Australian and global mining industries are experiencing an acute skills shortage. Mine managers, traditionally drawn from the ranks of mining engineers, are at the sharp end of this shortage. Exacerbating the shortage is a perception that a professional mine manager is not an attractive career option. This perception is influenced by the following forces which combine to make the role of a modern mine manager very demanding:legislative requirements for owners and managers to ensure (guarantee) the safety and health of employees; an increasing trend towards prosecution over exposure to risks to health and safety a need to be more aware and responsive to community and environment; financial, technical and æpeopleÆ pressures traditionally associated with the job of managing a mine; and mine management roles being filled by younger and less experienced professionals. Universities and other educational providers have the challenge of both ensuring that undergraduates are exposed to these issues during their study and continuing to promote mine management as a desirable career option. Anecdotal and statistical evidence indicates that young graduates are choosing and remaining in technical roles rather than taking on the challenge of mine management. Furthermore, it is suspected that the issues referred to above are contributing to the low retention rate of young professionals at mine sites. The challenges are not insurmountable, however. This paper reviews the initiatives of industry, the regulators and educational institutions in addressing these challenges. It includes a focus on:prosecution policies and their impacts, tertiary education program content and delivery modes, CPD initiatives of the Mine Managers Association of Australia, and alternative pathways for obtaining mine management qualifications.

Jan 1, 2006

By Y Peng, D J. Bradshaw, X Chen

At NewcrestÆs Telfer gold mine, a strategy of regrinding pyrite rougher flotation concentrates has been proposed to increase gold recovery and reduce cyanide consumption in the CIL circuit. The regrinding will be followed by an additional copper/gold flotation stage, where copper minerals need to be separated from pyrite. However, although the minerals are well liberated, the separation of chalcopyrite from pyrite in the cleaner stage is not always straightforward. The surfaces of the fine particles, produced during regrinding, are more easily oxidised and contaminated than coarse particles, directly influencing the particle floatability. The depression of pyrite is difficult in the cleaner stage as well due to copper activation, a process which is also highly dependent on the grinding environment. In this study, different grinding media, including mild steel and stainless steel, was used in the regrinding to produce different regrinding chemistry, such as, pH, Eh, and iron hydroxide contamination. The effects of regrinding conditions on chalcopyrite flotation and its separation from pyrite were studied. It was found that the stainless steel grinding media, which produced an oxidising environment, was more beneficial for the separation of chalcopyrite from pyrite after regrinding. The mild steel grinding media had a detrimental effect on both chalcopyrite and pyrite flotation. This study addresses the importance of choosing suitable regrinding conditions in the pyrite and copper flotation circuit.CITATION:Chen, X, Peng, Y and Bradshaw, D J, 2012. Effect of regrinding conditions on the flotation of chalcopyrite and its separation from pyrite in the cleaner stage, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 279-286 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012