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By Mark Ioli, Debra Struhsacker

In September 2004, Gale Norton, U.S. Secretary of the Interior, presented the Manhattan Mine with a U.S. Bureau of Land Management’s 2004 Hardrock Mineral Environmental Award. The Manhattan Mine is a sustainable development showcase. The reclamation accomplishments at this Nevada gold mine demonstrate how modern reclamation techniques can restore an old mining district into an aesthetically pleasing landscape that can support multiple and sustainable uses. In a collaborative effort that relied on substantial community involvement, Round Mountain Gold Corp.(RMGC) has improved the environment and eliminated a number of public hazards associated with old, unsafe mining features. RMGC’s community collaboration, innovative engineering, creative reclamation design and corporate commitment to environmental excellence show what Secretary Norton’s 4 Cs Initiative looks like on the ground and inaction.

Jan 1, 2005

By Paul J. Lewis

Estimation of the axial side shear resistance of drilled shaft rock sockets is directly related to the unconfined compressive strength of the bedrock. Commonly, the mean unconfined compressive strength value is calculated from a range of laboratory test results and is used to estimate the side shear of the bedrock. This paper presents the results from a full scale axial load test performed on an 8.5-feet-diameter drilled shaft rock socket, and compares measured side shear values to estimated values for two different rock strata. Measured side shear values correlated well with the design value calculated for the "strong" rock stratum, but did not correlate well with the design value calculated for the "weak" rock stratum. The mean unconfined compressive strength was used to calculate the side shear in both strata, but review of the laboratory data indicates that this value may not have been appropriate for the weak stratum due to a large variation in the laboratory test results. Also included in this paper is a discussion of the subsurface conditions, the laboratory test results, and the methodology used to design the drilled shaft rock sockets for axial and lateral resistance.

Jan 1, 2005

By Michael G. Rulff, Tracy M. Holmes

"Vast amounts of time and money are spent fighting flow problems in plants that involve the handling or processing of industrial minerals. Because these types of projects tend to be capitalintensive, the right decisions, made at the design stage, can have a substantial positive effect on the economics of the project.Some of the problems related to solids flow in mineral processing plants include:•,Flow stoppages•,Uncontrolled flow•,Segregation of blended materials•,Build-up and dead material resulting in loss of live capacityUnfortunately few Universities in North America provide courses in the design or selection of bulk solids handling equipment, let alone the theory of bulk solids flow, with the result that engineers do not fully appreciate the effects of bulk solids handling on their process. The usual method of selecting “standard” equipment, all too often, leaves plant operators hammering on hoppers to promote flow, a technique that is not only usually ineffective but also unsafe and often causes damage to equipment. In short, too little consideration is given, at the design stage of projects, to the particular material and operating environment involved and how these will affect handling between process steps.This paper seeks to give a general understanding of bulk solids flow theory including flow patterns and flow property tests, and presents functional design guidelines to ensure reliable flow. As well, a case history will be presented. Our message is clear: To ensure uniform, reliable flow, a plant design must take into account the specific flow characteristics of the bulk solid to be handled or processed."

Jan 1, 2008

Perhaps one of the most important conferences or symposia which our Institute has conducted, was the joint Aus. LM.M./AJ.M.E. meeting held in Canberra in May 1978, with the theme International Resource Management (Woodcock, 1978).We were privileged to witness active participation in the meeting by outstanding personalities from the mining and metallurgical industries of Australia and New Zealand, the United States of America, Canada and the United Kingdom and to hear addresses on subjects of international significance to the mining and metallurgical industries.Our Institute is one concerned with professionalism.The principal objects of The Institute as described by our founders include, "promoting the arts and sciences connected with the economical production of the useful minerals and metals, and the welfare of those in the industries, by meetings for social intercourse, and the reading and discussion of professional papers, and to circulate by means of publications amongst its members and associates, the information thus obtained".Sir Maurice Mawby (1968) said in his Presidential Address to the Institite, "the most important aspect of these objects was the promotion of the arts and sciences of the mining industry".Why is it then, that a large proportion of the papers given at the meeting in Canberra dealt with world wide social aspects of the mining and metallurgical industries, rather than the technology, the arts and sciences of mining and metallurgy as principal factors in international resource management?The answer is quite simple of course, and that is that the social and political factors are the principal factors which create the demand for basic raw materials and in the long term determine the costs and prices of the commodities which our professional abilities are drawn upon to produce.

Jan 1, 1979

By Sam Yao, Ali Naeem, Sara Barrett

Brooklyn Basin Project is a multi-billion-dollar development of the former Port of Oakland 9th Avenue Terminal located along the Oakland Estuary of California. A centerpiece of the development is the 10-acre shoreline park which will be built on a 1,200 ft long by 225 ft wide historic wharf. The wharf was built in the 1930’s on concrete and timber piles with a flat concrete slab. Prior to constructing the wharf, a rock dike was placed to protect the shoreline. The presence of the rock dike increased the hazards from lateral spreading of the underlying bay mud and non-ductile shear failure of piles driven through the dike. To open the park to the public, the wharf required a seismic retrofit in compliance with the California Building Code. The paper presents the results and conclusions of the following topics: • Structural condition assessment and repair strategies for the existing wharf deck, piles and jackets • Application of the California Building Code (CBC Ch31F) for the performance-based seismic evaluation of existing piers and wharves • Nonlinear pushover analysis of the wharf including the combination of inertial and kinematic effects • Impact of rock dike on lateral spreading and kinematic effects and the significance of existing piles in stabilizing the lateral spreading of the rock dike • Retrofit strategies for the wharf to meet the required seismic performance requirements per the California Building Code and reduce the demands on existing piles which were driven through the rock dike INTRODUCTION The 65-acre Brooklyn Basin Development project is located in Oakland, California. The project consists of 3,100 housing units, 200,000 sq. ft of retail and commercial space, along with various parks and public access improvements along the Oakland Estuary. A centerpiece of the development is the 10-acre Shoreline Park which will be built on a 1,200 ft long by 225 ft wide historic wharf. The wharf was built in the 1930’s on concrete and timber piles with a flat concrete slab. As shown in Figure 1, the wharf deck and piles support the 9th Avenue Terminal Building.

Jan 1, 2018

By R. Zunich, E. Rybinski, M. Grondin, B. Flintoff

It is uncommon these days to read a business magazine or newspaper without finding a reference to Knowledge Management (KM), and its critical importance to corporate success. One definition of KM is: “getting the right knowledge to the right people at the right time and helping them to put information into action in such ways that strive to improve organizational performance.” In the minerals processing industry we could assert that we have been practicing this for years through effective operator training. In most cases we would probably be wrong. Training has certainly filled the need of addressing safety and basic operational issues, but we must collectively focus on education (learning), and the difference, as measured in outcomes, is not at all subtle. This paper briefly examines the history of training and education in the mining industry, and looks in more detail at the impact of one company’s approach to empower its workforce, while keeping the ultimate goal clearly in mind: “The great end of knowledge is not knowledge, but action.” (T.H. Huxley)

Jan 1, 2001

By W. Abdellah

The purpose of this paper is to establish a qualitative method to estimate the risk level (e.g. rating and ranking) resulting from mining activity. Risk is the product of two factors: probability of failure and cost of consequences. A resultant assessment scale matrix is then used to assign a risk index value which is directly proportional to the potential for excavation instability. A case study, the No. 1 Shear East orebody at Vale?s Garson Mine in Sudbury, Ontario will be examined. A three-dimensional, elastoplastic, finite difference model (FLAC 3D) is presented for a mine development intersection situated 1.5 km below ground surface. The developed assessment scale matrix is used to estimate risk index for intersection (2981) located on 5000 level. The results are presented and categorized with respect to risk-index value, probability of instability, cost of consequence, and mining stage.

Jan 1, 2014

By C Johnstone

Project management is not a task to be undertaken lightly. Mining projects generally present even more challenges due to ChinaÆs remoteness and complexity. Having experiences in project management in the West is certainly an asset, but China can present the uninitiated with any number of headaches. To undertake a project there can have many problems that are unique to China. For the last 15 years, China has seen an increasing number of foreign capital investment projects in the mining industry. Practices involved in mining project development have experienced/are experiencing an evolution. Since 1996, Sino Gold Mining Ltd has delivered three mines in China, ie Jianchaling Gold Mine, Jinfeng Gold Mine and White Mountain Gold Mine. Through the work, Sino Gold has established a solid knowledge base and a capable and skilful workforce in effectively undertaking mining projects in China. This paper is concerned with the experiences accumulated so far by Sino Gold in project management in China. An overall review is conducted regarding the reform of the mining project development in China. Opportunities and challenges are highlighted within the political, economic and culture context. Brief summaries of the development of the three gold mines are presented.

Jan 1, 2009

By R L. Braithwaite

Mesothermal quartz lodes in Paleozoic Greenland Group metasediments of the Reefton area have produced 67 t of gold up to 1951, and recent exploration has identified new gold resources in several deposits, including the largest past producers, Blackwater and Globe Progress. The metasediments consist of alternating sandstone and argillite, metamorphosed to lower greenschist facies and hydrothermally altered near the quartz lodes. We examined and sampled drill core from four prospects, Globe Progress, General Gordon, Merrijigs and Blackwater, to determine the mineralogical and geochemical characteristics of hydrothermal alteration in the sandstone units. The sandstones are feldspathic litharenites averaging Q65, FlO and R25, with detrital grains of quartz, feldspar, rock fragments, muscovite, biotite (mostly altered to chlorite), and trace quantities of graphite, apatite, zircon, tourmaline and titanite. Hydrothermal alteration has developed a secondary mineral assemblage of K-mica (muscovite, sericite and illite), carbonate, chlorite, pyrite, arsenopyrite and limonite. The abundance of secondary chlorite is greater at Blackwater than at the other locations studied. Features in the sediments associated with increasing hydrothermal alteration towards quartz lodes include, the development and increasing intensity of colour bleaching and carbonate spotting, increasing quantities of disseminated pyrite and arsenopyrite, and the appearance and increasing quantity and size of thin carbonate, quartz and sulphide veins. This is accompanied by increasing concentrations of sulphur, arsenic and antimony as shown in assays, and of volatiles (loss on ignition) and iron as seen in XRF analyses. We were unable to identify consistent trends in the behaviour of potassium, sodium, and calcium that are exhibited by similar mesothermal quartz lode deposits inVictoria, Australia.

Jan 1, 1998

By Luke Keeney, Stephen Walters

"The start up of a new mining and metallurgical facility is a crucial step in the life of any mining project. The mining industries record is poor when evaluating processing plant operation relative to design capacity predictions made during feasibility studies. Multivariate geometallurgical orebody characterisation, using principle component analysis, is a method developed for improving predictive processing performance models during feasibility stages of mine development. This paper outlines the application of multivariate geometallurgical characterisation to the Cadia East deposit located in New South Wales, Australia. Cadia East is a low grade high tonnage copper-gold porphyry system in advanced stages of feasibility analysis. A dataset of ~32000 measurements and 150 comminution parameters (A*b and BMWI) has been used to develop class-based characterisation and modelling methodologies. The results of this study outline the development of class-based ore characterisation and provide a technique for analysing and interpreting large and complex geometallurgical datasets for prediction and optimisation of processing performance. The results enable sophisticated population modelling to be conducted which displays deposit scale processing variability, aiding circuit design specifications and predictions during feasibility studies.INTRODUCTIONA feasibility study is the major technical report on which the decision to proceed to production and on which financing is based (Shillabeer & Gypton, 2003). The mining industry’s record is not very good when actual construction time, costs, and operating performance are compared to the projections made in feasibility studies (Ballard, 1983; Gypton & Ward, 2000; Gypton 2002). A study by McNulty (1998) found that of 41 mineral processing and chemical plants built between 1965 and 1995, only 56% achieved design capacity within two years of commissioning and three were closed after failing to achieve design capacity within 36 months of start up (Shillabeer & Gypton, 2003). McNulty (1998) related this underachievement and failure of start up performance to the use of innovative process technology without appreciating and managing technical risk. Factors contributing to technical risk include inadequate pilot plant testing, scaled up prototype equipment without backup, design flaws and poorly understood complex process chemistry."

Jan 1, 2009

By T Goswami

The conventional practice in open cut coal strip mining has been to blast the overburden or coal layers in separate blast events. This is done in order to maximise the benefits from throw blasting and also to limit coal losses. Each blast event usually has a particular design of hole diameters, burdens and spacings, explosive charges and blast timing in order to achieve the required blast outcome for either the overburden or coal. This means that each blast has to be separately cleaned on the surface after excavation of the previous blast. Hole locations then have to be individually surveyed and marked, holes drilled, explosives and initiators loaded and the blast fired. Each of these actions takes considerable time and resources and therefore impacts on mine productivity. The mine has to be cleared for each blast event and every blast presents a new potential source for noise, dust or vibration disturbance to the neighbouring population. Exposed highwalls are also subjected to vibration and damage from each subsequent blast event

Jan 1, 2006

A discussion on simulation tools to aid the development of robotics platforms is presented. The focus of the work is towards mining robotics platforms where operations are typically in unstructured, unpredictable environments and a high degree of dependability in their operations is required. It is argued that a test-based development approach leads to more robust solutions and faster development cycles than traditional single-track field-only development and that the key enabling technology for this development paradigm is the judicious use of simulation tools. The future direction of simulation for use in online applications such as active planning and as a means to assist tele-operation in high latency communication applications is also brief y considered together with the requirements for a useful simulation environment in terms of the simulator architecture. Finally, a case study is presented on the application of the discussed methodologies to an unmanned ground vehicle (UGV) for earth-moving tasks, which is being developed in an accelerated time frame with a transient development team.

Dec 6, 2010

By S. C. A. Franca, M. T. Millqvist, A. B. Luz

Laboratory experiments were performed on a Brazilian diatomite from Bahia State to produce an industrial product for use as a filter aid. Bench and pilot plant tests were conducted consisting of: diatomite desegregation, organic matter and clay removal, filtration, drying and calcination. Calcination temperature and sodium carbonate addition influenced diatomite particle size distribution. Optimum filtration rates for calcined products were obtained at 900°C and 47 min. residence time with 3% (w/w) of sodium carbonate addition, and resultant products met specifications imposed on filter aids.

Jan 1, 2002

By W. A. Calhoun

This report gives results of metallurgical investigations performed by the Bureau of Mines on mineral samples taken during April 1959, from Hawaiian bauxite deposits on the islands of Kauai, Maui, and Hawaii. The bauxite samples were tested at the Bureau's Rolla Metallurgy Research Center, Rolla, Mo., to determine if alumina could be extracted. The results were encouraging. Extraction of the alumina by the American Bayer type digest of crude ore samples from Kauai, Maui, and Hawaii recovered 78.8, 73.1, and 70.0 percent, of the total alumina, respectively. These recoveries were increased to 82.8, 85.5, and 79.5 percent by modifying the treatment, which consisted essentially of calcination and weak caustic desilication to provide a residue. The residue was then treated with calcium oxide and digested in a strong caustic solution to extract the alumina.

Jan 1, 1962

By Michael S. Kucker, Stuart Warren, Robert A. Robinson, Michael J. Lehnen, David McAllister

Geotechnical conditions exposed by the phased exploration programs have had a major impact on the selection of excavation and support methods, dewatering requirements, size of openings, vertical alignment, and estimated cost of construction for the Beacon Hill Tunnel and Station section of the “Link” Light Rail. Beacon Hill is comprised of a very complex glacial geology, including numerous slickensided fractures, injected sand dikes, and multiple perched groundwater levels as revealed by a phased boring program and exposed in a test shaft. The Geotechnical Baseline Report (GBR) presents this complex geology along with a “tool box” of alternative additional support systems to accommodate the varying ground conditions during construction of the station excavation. Additional explorations will also be accomplished during construction to further refine the geotechnical interpretations and provide an opportunity to use pro-active ground improvement techniques to optimize the station excavation and support requirements.

Jan 1, 2005

By Brendan Demich, Brendan Macdonald, Timothy J. Orr, Jason Navoyski, Jennica L. Bellanca, William J. Helfrich

Recent advances in computing, rendering, and display technologies have generated increased accessibility for virtual reality (VR). VR allows the creation of dynamic, high-fidelity environments to simulate dangerous situations, test conditions, and visualize concepts. Consequently, numerous products have been developed, but many of these are limited in scope. Therefore, the National Institute for Occupational Safety and Health researchers developed a VR framework, called VR Mine, to rapidly create an underground mine for human data collection, simulation, visualization, and training. This paper describes the features of VR Mine using self-escape and proximity detection as case studies. Features include mine generation, simulated networks, proximity detection systems, and the integration and visualization of real-time ventilation models.

Shaft sinking through an amphibolite-granite rock mass experienced rock bursts on the shaft walls and benches. However, rock burst phenomena was exhibited only in granite, which is e1asto-brittle with ability to store strain energy caused by orogenic and man made stresses. To improve ground conditions, blasting of destressing holes at shaft corners was carried out. By this technique rock burst during shaft sinking was minimized, but not eliminated.

Jan 1, 1982

By Claude Bazin, François Robichaud

"The control of the operation of semi autogeneous grinding (SAG) mills is mainly achieved through adjustments of feed rate, water addition and speed of rotation. With the introduction of image based sensors it is possible to have on-line measurements of the size distribution of the ore feeding a SAG mill. This information could be used for the development of a control strategy to regulate a SAG mill feed size distribution to a set-point. The control of the size distribution is carried out by adjustment of the speed of the ore extractors underneath the ore stockpile. The potential and difficulty associated with the implementation of such control are assessed using a multivariable statistical analysis of data collected from the operation of the grinding circuit of the Agnico-Eagle Goldex mine in Val d’Or, QC. A control strategy for the ore feed size distribution is assessed using a simulator of the ore stockpile operation.INTRODUCTIONThe popularity of autogeneous (FAG) and semi autogeneous (SAG) grinding mills has been increasing over the last 20 years (Napier Munn et al., 1996). These mills use the ore or a combination of ore and steel balls as the grinding media. Since the ore is used as a media for the size reduction the mill ore feed size distribution impacts the performance of the mill. Several papers were recently published on this subject (Dance et al.,2011; Wennen & Murr, 2011; Dance & Valery, 2011; Allaire et al., 2011) showing the advantages of preparing the feed size distribution to maximize the circuit throughput or mill efficiency (Wennen & Murr, 2011; Dance & Valery, 2011; Allaire et al., 2011). With the availability of particle size sensor based on image analysis of the ore on a conveyor (Partanen et al., 2001; Bobo et al. 2004; Edwards et al., 2002; Wei & Craig, 2009) it is possible to control the size distribution of the ore feeding autogeneous or semi autogeneous mills (Partanen et al., 2001).This paper describes a method to control a size distribution index to a set point via the manipulation of the speed of the extractors that withdraw the ore from the stockpile feeding the grinding circuit. The paper consists of 4 sections. The first section describes the considered grinding circuit. A statistical analysis of the collected data on the grinding circuit is presented in the second section. This analysis demonstrates the necessity of using real-time adaptation mechanisms to develop a control strategy for the size distribution of a grinding circuit. The third section describes the method used to simulate the ore stockpile operation and the last section describes the preliminary development and assessment of a control strategy of size distribution of the ore feeding a SAG mill."

Jan 1, 2013

At last year's. annual meeting of The Institute, Sir George Fisher, as President, compared it somewhat nostalgically with a meeting of its kind in the 1920s when comment was expressed on the decline of Australianmining and on the lack of new mineral discoveries.I feel that tonight's annual meeting is even more an occasion for nostalgia, for it represents the seventy-fifth anniversary of the founding of The Australasian Institute of Mining and Metallurgy. I hope, therefore, that I may be allowed to retrace some of the circumstances of this Institute's origin and at the same time to look at some of the broader happenings of those 75 years.From this distance in time it is, of course, much easier to get things in perspective and one of the things that compels enormous admiration in looking back over the history of our Institute is to note the qualities of foresight and keen concern for professional standards which moved the pioneers in this Institute. They had no benefit of hindsight to aid them.Just over 75 years ago, a small group of men met in Broken Hill to discus.s the possibilities of forming an association of mining engineers. The moving spirit was Uriah Dudley, our first secretary, manager of the Umberumberka mine at Silverton. The first formal move to form an association of mining engineers came from the Amalgamated Mining Managers Association of Australasia. At the time, this association was a fairly new group, being 5 years old.It had been formed to try to raise the standard of management throughout the industry. Uriah Dudley and our first provisional president, John Howell, held their first talks in 1891 and further meetings at Broken Hill followed. The inaugural meeting, attended by 200 members, was held in Adelaide in April, 1893.

Jan 1, 1968

Before presenting this address I desire to express my appreciation of the honour which has been conferred on me by my election as iPresident of The Australasian Institute of Mining and Metallurgy. At this stage it might not be out of place to recall that Broken Hill was the birthplace of The Australasian Institute of Mining and Metallurgy, originally formed as the Australasian Institute of Mining Engineers in 1893.In selecting for my address the topic of "The Broken Hill Mining Industry and its Contribution to the Economy of Australia" I realise it is impossible to cover fully every aspect of the nation's economy which owes all or part of its origin to the Broken Hill field. Nevertheless, I feel that some attempt should be made to give credit to the Broken Hill mining industry for its part in the progress which Australia has made over the past seventy years.. If we care to reflect for a moment it soon becomes apparent that, not only is the Broken Hill mining industry an important producer of base metals for domestic and overseas consumption, but its profits have provided the means whereby many of Australia's leading secondary industries have been established or built up. Examples which come to mind are the founding of the iron and steel industry by the Broken Hill Proprietary Company; the establishment of plants at Port Pirie in South Australia, and at Risdon in Tasmania, for the production of metallic lead and zinc; and also at Port Kembla for the smelting of copper ores. From profits derived from operations at Broken Hill, capital has also been provided to assist other new essential...

Jan 1, 1956