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By Kenichi Fujino

Severe disasters have struck Japan in recent years. Following these disasters, construction robots have played important roles in investigation and restoration work in the disaster regions. To be applied in this way, construction robots require many functions according to the purpose of their use in each case. There are clear differences in the functions and usage conditions required by investigation robots and those required by execution robots. These differences will be important when designing and operating construction robots in the future. This report introduces a volcano exploration robot and unmanned execution system as examples of construction robots used for investigations and executions respectively. Based on this, the report organizes important characteristics of construction robots and explains differences in the concepts of disaster investigation robots and disaster restoration robots. Because they are used in harsh natural conditions and do not have any execution functions, efforts are made to clarify the fact that investigation robots have to overcome many problems such as mobility. When a construction robot is used, the scenario of the operation of the construction robot (execution plan) is extremely important, and in addition, it is necessary to clearly define the way it will be used according to the purpose of its use and specification conditions. In a plan for an unmanned execution system, it is possible to mitigate several strict prerequisite conditions by proposing a well-constructed execution plan. For example, the execution efficiency of an unmanned execution system can be improved by effectively using a temporary road.

Aug 1, 2013

By A. Dave Mackintosh

Historical closure data has provided a description of the stress distribution patterns occurring around mine openings and enabled the development of a time ? distance plot predicting the location of the stress peak and its migration away from mine openings with time. Data collected from active mining areas during the 1970?s and 1980?s indicated the peak appeared to stabilize approximately 135m (450 ft.) from openings after four years. The region of high load and accompanying poor ground conditions in which the peak was centred was spread over approximately 45m (150 ft.) to 60m (200 ft.). Recent data from new development headings cut adjacent to 25 year old extraction areas suggests load transfer takes place over a much greater distance and time frame than predicted.

May 1, 2001

By R. Clarkson

"Free gold particles occur in many base metal and precious metal mines throughout the world. Due to the high density and malleability of gold, large circulating loads of free gold particles can build up over time in grinding circuits. This gold is often deposited in unintended traps throughout the mineral processing system.These unidentified free gold deposits represent a serious security risk as well as an inaccessible inventory of gold. Deposits of free gold particles often remain undetected by mine management until they are accidentally discovered while repairing mill equipment.Nuclear tracers have been used to determine the free gold recovery efficiency of gravity recovery equipment, drills, and sampling equipment (Clarkson, 1994, 1995; Walsh and Rao, 1986; Walsh and Kelly, 1992). In November, 1993, the author inspected the grinding circuit at La Mine Doyon in Rouyn-Noranda, Quebec and made recommendations to recover coarse gold and to eliminate gold traps from the circuit. In 1995, the author salted mineral processing circuits with radioactive gold particles. The gamma and X-ray radiation from gold’s nuclear isotope (Au198) were detected through steel, in pipes, and in moving equipment using scintillometers. The radiotracers proved to be a safe, rapid and accurate method of identifying gold traps and improving security.Nuclear TracersWhen particles of gold are placed in a nuclear reactor, some of the gold atoms (Au197) absorb another neutron in their nucleus to form gold’s radioactive isotope (Au198). In the process of radioactive decay, this isotope emits high energy gamma rays and X-rays which are easily detected (even through steel) with scintillometers.Radioactive gold (Au198) has a very short halflife of 2.7 days. At the relatively low activity levels used for tracing, the particles remain detectable with a small hand-held scintillometer for about 10 to 14 days. After 14 days the irradiated gold is close to background levels and within two months it is essentially non-radioactive. The radiation has no effect on the recovery characteristics of the gold particles. The gold radiotracers are very safe due to their very low level of radiation, short half-life, and their inherent physical and chemical stability. However, the use and possession of even mildly irradiated gold is strictly licensed and regulated."

Jan 1, 1997

By S. Kodama, G. Sasaki, K. Matsugi, K. Sugio, Y. B. Choi

"Pure aluminum (Al) matrix composites with changing the volume fraction of TiB2 particle content from 10 to 30% was fabricated by spark plasma sintering (SPS) process. Then the microstructure, density, dispersibility and thermal conductivity of the composites was estimated. As increasing TiB2 content, the dispersibility of particles and the density of the composites degraded slightly. And, the effect of the dispersibility of TiB2 particles on the thermal conductivity was quite little. The thermal conductivity of the composites was less than the theoretical value calculated by Maxwell-Eucken equation considering the effect of the density. It is due the influence of the interface heat transfer rate, because these composites have many small sized particles and have high interface density.INTRODUCTION Recently, metal matrix composites (MMCs) have been used widely in electric / electronic components, architectural materials, transportation equipment, aerospace and a precision instruments, because it’s superior properties have been greatly watched. Demand of MMC for industrial use has been increasing gradually. Furthermore, multifunction properties are required for the composites strongly. By integrating the dissimilar materials, the composites have various properties that we cannot get from monolithic materials. On the other hand, the response to the thermal management is required for materials, recently, and the need for the structural material controlling the thermal conductivity has been increasing. Especially, superior thermal conductivity and good mechanical properties from room temperature to high temperature are required for heat sink and heat exchanger at the same time. In late years, a study on the composites combining carbon materials and aluminum and copper has been developing, and actually the composites with high thermal conductivity which is not provided in the conventional materials is developed. On the other hand, non-oxide ceramics particles such as SiC and AlN, TiB2 have good thermal conductivity. Particularly, as TiB2 has good electrical conductivity, TiB2 containing MMCs is expected as innovative materials used as electric/ electronic components. Furthermore, as TiB2 has low density, high melting point, low thermal expansion and good deformation resistance, the development of high performance composites with multi-functional properties is expected. As thermal conductivity of pure Al and TiB2 are 225 and 66.4 W/mK, respectively, it is expected that the degradation of thermal conductivity by adding dispersant in Al matrix is suppressed. The authors have carried out a thermal conductivity, electrical conductivity, mechanical properties of 20 vol.% TiB2 dispersed Al composites (Sugio, 2016, Sasaki, 2016). In this study, the influence of quantity of addition of TiB2 on microstructure, thermal conductivity was studied minutely."

Jan 1, 2018

By J. F. Henderson

Stable mining operations commenced in the Northwest Territories in 1933. Pitchblende from Great Bear lake and gold from the Yellowknife district are the main minerals produced. The value of pitchblende products produced from 1933 to 1941 was nearly $6; 000; 000; data on subsequent production are not available. The first gold was produced from the Con mine at Yellowknife in 1938. Other properties that later came into production include the Negus; Slave Lake; Thompson Lundmark; and Ptarmigan mines. The annual gold production reached $3; 862; 000 in 1942 but due to the war and consequent labour shortage fell to $333; 218 in 1945. The only producing mines at present (May; 1947) are the Con and Negus; but several promising properties are under development; including that of Giant Yellowknife Gold Mines where large tonnages of ore are being blocked out. With the reopening of former producing mines and new production from properties now being developed; gold production should rapidly increase and exceed its former peak within the next few years.

Jan 1, 1954

By E. Sharifi, B. Komishke, R. Heffel, D. Schwartz

"The oil sands resources in Canada are one of the world’s largest hydrocarbon deposits. Processing of oil sands uses hot water to extract bitumen. The process generates tailings slurry that must be settled for final deposition. The tailings contain fine material, with poor water release characteristics which makes water recovery challenging. Polymer flocculants are added to assist in settling and dewatering the fine tailings. The amount of polymer addition is dependent on tailings characteristics, including the particle size distribution (PSD). If the PSD of the tailings is unknown, an excess amount of polymer needs to be added in the dewatering stage to flocculate the particles. Over flocculation also has a detrimental effect on the water release characteristics. Measuring the particle size distribution using an on-line analyzer could have major benefits over common laboratory methods as it provides online and fast insight into the process enabling the operators to implement required changes to minimize the reagent consumption, while achieving optimal flocculation. Online measurement of PSD using laser diffraction has long been used in base metals beneficiation processes. A series of test work using Outotec PSI500® particle size analyzer on oil sands samples from different operations have been conducted. Tests were performed by recirculating the slurry in closed circuit to simulate real plant conditions. This paper presents a summary of the results.INTRODUCTION Canada’s oil sands are the third largest reserves of crude oil in the world, with an estimated 165.4 billion barrels of recoverable oil (Government of Alberta 2016). Oil sands are a mixture of sand, water, clay and bitumen. Bitumen is a form of oil that is too heavy or thick to flow or be pumped without being diluted or heated. About 20% of bitumen reserves are close enough to surface to be mined. In mining methods, oil sand is transported from an open pit mine to the processing plant and bitumen is separated from solids and water. The separation process involves ore preparation, such as addition of hot water, steam and caustic (NaOH), followed by gravity separation and froth treatment (Masliyah et al. 2004). A general scheme of the extraction process is presented in Figure 1."

Jan 1, 2018

By J. Xie

In underground coal mining, the potential for an outburst of coal and gas is considered to be one of the major hazards. As such, considerable emphasis is given to understanding and preventing such events. A number of indices are used in the prediction of the outburst in a coal mine. The main indices include initial gas desorption rate, gas pressure, gas content, coal strength, gas flowrate from a borehole drilled in a coal seam, and combinations of the above. Some of these indices are considered to be inadequate, inappropriate or impractical for some coal seam conditions, such as those with soft and friable coal. The Huainan Mining Group (Huainan) in China and the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia have been jointly developing gas content based technologies to predict the risk of the outbursts. One of the major progressive achievements is a new method for determination of outburst gas content threshold values. The method utilizes empirical analyses, numerical modeling, and seam-specific knowledge . This paper describes the method and its application for the #11 Seam at Guqiao mine, Huainan.

Aug 1, 2013

By T. F. Pugsley, D. Gignac

"The historical background to the project dates back to the mid-30s with the discovery of surface sulphide showings in the Cape Smith-Wakeham Bay ultramafic belt. In the mid1950s, orderly exploration commenced with an extensive work program by Asarco, INCO, Lemoine, Falconbridge and Raglan Nickel Mines Ltd. on exploration permits. In 1966, Falconbridge and Raglan Nickel Mines interests merged. Extensive exploration, drilling, under- ground delineation of the Donaldson orebody and the construction of basic infrastructure such as camps, airfield, road links from Douglas Harbour to Donaldson and Katinniq, a distance of 60 km, were completed.Production project design at that time consisted of plans for a 50 000 mt per year nickel mining and concentrating operation, including a 2000 person community and smelter at Douglas Harbour. These plans unravelled in the mid-70s due to high capital costs, poor nickel market conditions and the realization that the Raglan orebodies were not large enough to economically support the construction of green field smelter and refinery facilities for processing Raglan production. Nickel market conditions in the late 70s and early 80swere generally poor, resulting in further delays on production plans.While recognizing the very high potential to discover increased tonnages of high grade(3% Ni) in excess of 20 million tonnes, the project was deferred into the late 80s when a serious re-evaluation of exploration potential occurred and the requirement to prove up additional reserves resulted in an underground exploration program at Katinniq covering the period 1990-1992."

Jan 1, 1996

By Peter Moser, Thoma Oberndorfer

"Within the research project “Mine Development” (Fettweis and Moser, 1990) a PC-based mine database has been built up since 1991 and so far includes detailed technical and economic data of about 150 under-ground hardrock mines in industrialized countries worldwide. These data represent about 50% of the underground hardrock mines in west and central Europe, Scandinavia, United States, Canada and Australia (Fig. 1). The mining operations included in the database have been visited directly and analyzed with respect to their deposit conditions, their general design and layout and also their operational and economic performance.The main aim of the Mine Database is to make a contribution to an improved planning of new underground hardrock mines. An analysis of current mine planning practices shows, that both personnel and company experience is still a dominant factor in planning new underground hardrock operations. Through the information included in the Mine Database the experience of a single per-son or company is supplemented by the experience of a wider group of people. The Mine Database makes the huge amount of experience that is available worldwide in the field of under-ground mining accessible for new mining projects. From that a contribution to a more reliable mine planning procedure based on the performance of existing mining operations is expected.In addition to its use in planning new mining operations, the Mine Database can con-tribute to the exchange of technical data among different mining operations, especially on equipment performance, etc. Such an information service is offered by the Department of Mining Engineering & Mineral Economics in Leoben and is already being used by different mining companies. To respect proprietory information, company specific information is not released under any circumstances.The cost of building up the Mine Database, so far, is about US$500.000 — two thirds of which is labour, and one third, travel."

Jan 1, 1996

By B. Wasmund, M. Parravani, M. Jastrzebski, Z. Coull

"One of the main drivers of overall profitability of pyrometallurgical vessels is refractory lining campaign life. Increased economic pressure to improve vessel life requires innovative solutions to the problem of refractory cooling. Hatch has recently developed a high-intensity, waterless cooling system that bridges the performance gap between external shell cooling and internal water-cooled copper elements. External shell cooling has a limited effectiveness in protecting the refractory lining, because it is thermally insulated from the hotface of the lining by its thickness. This situation does not improve until the lining itself has become worn near the end of the campaign. The patented technology developed by Hatch overcomes this problem by positioning high-velocity air-cooling channels within the lining, closer to the hotface where the cooling benefits can be realized throughout the entire duration of the campaign. The current paper presents the development and application of Internal Air Cooling technology as well as results from the pilot campaign in an operating commercial vessel. Various adaptations for this novel, cost-effective and inherently safe system are also discussed."

Jan 1, 2015

By Agbo Chima

Low-lying sections of open-pit mines accumulate water, especially during the rainy seasons, preventing access to resource-bearing areas. To sustain mining operations, the water must be lifted out of the flooded pits at a high flow rate using pumps. These pumps need to be mobile so that they can be removed during drill-and-blast operations. Most mobile pumps rely on diesel engines with high maintenance requirements. A special pump design was developed to address the unique needs of open-pit mining while making the dewatering process more sustainable. Using the target flow rate and head data, an efficient pump was designed, encased, and deployed in the open pit. A variable speed drive (VSD) was installed in a protective skid so that the pump could be tuned to match the preferred flow rate at any point during its operation. This system was tied to the national electrical grid instead of being powered by diesel pumps, which reduced the carbon intensity per kilowatt-hour. The high availability, low maintenance requirement, and greater reliability reduced the use of spare parts, the fuel consumption, and the logistics associated with operating the pump. This further reduced the carbon footprint of the dewatering process. This paper provides some of the two-year performance metrics for a deployment in West Africa. With a focus on availability, maintenance costs, average cost per volume lifted, and carbon footprint, this encased pump system is compared to the diesel-driven pumps that it aims to replace.

Jan 1, 2023

By J. E. Dutrizac, J. B. Sunstrum

"Lead was among the first metals known to man, and there are indications that lead was produced by the reductive smelting of galena in the mountains surrounding the Black Sea as early as 3000 B. C .(1). The early metallurgists soon discovered that silver could be recovered from lead bullion by cupellation techniques, and that the litharge product of the cupellation process could be reduced to give silver-free lead metal. By the Graeco-Roman era, lead-silver ores were being extensively exploited for both their silver and lead contents. Although silver was always of prime concern, a number of industrial uses existed for lead that included piping and sheeting. Subsequently, lead metallurgical practice developed steadily in different parts of the world, and was a relatively mature technology by the time of the European colonization of North America. In the United States, lead was produced on a small scale as early as 1720, and by 1800, the extensive Pb-Zn deposits of Missouri-Kansas and the upper Mississippi Valley were being developed(2). Many of the early American lead ores were low in silver, and seemed to have been worked primarily for their lead contents. Major uses of lead at the time included bullets, pipe and sheeting. During the period 1860-1890, the silver-rich galena ores of the western United States were exploited, and a number of lead smelters were operated. Although all the smelters produced lead metal, the recuperation of the associated silver and gold values was generally of prime concern. In Canada, lead deposits are abundant, and galenarich outcrops frequently attracted the attention of the early explorers and prospectors. In fact, the first record of a Canadian ore deposit seems to have been the observation of an argentiferous galena vein near Lake Temiscamingue in 17 41(3). The presence of silver-bearing lead deposits naturally attracted the attention of the mining community, and many outcrops were worked throughout the country. Because of the problems associated with transporting lead concentrates to existing American or overseas smelters, attention soon shifted to the establishment of local lead smelting facilities. The purpose of this article is to examine those early smelting efforts and to try to identify the first ""successful"" Canadian lead smelter."

Jan 1, 1999

By Mike Robotham

Drum hoists in the 21st century have the same fundamental objective as their earliest 19th century counterpart. And yet a lot has changed in the design of the hoist from those early days of underground mining. These changes are driven by the need for greater productivity and reliability at ever increasing depths without compromising the all important safety demanded by the industry today. This paper reflects on how these changes have influenced design of a modern hoist Director of Engineering, Mike Robotham is a chartered engineer and has been with DavyMarkham for over 30 years. Having completed a craft apprenticeship he later joined the engineering department as a junior engineer. He has a wealth of experience of working on medium to large engineering projects in the field of mechanical, electrical and hydraulic equipment

May 1, 2013

By T. Johnson, D. Kelley, J. Graham

"Hydrometallurgical processes can be exceptionally corrosive. Conditions associated with metal extraction and refining require materials of construction that can withstand process acids and acid chlorides at temperatures up to 90°C (194°F). Process vessels, piping, scrubbers and ducting can be rapidly compromised in these aggressive environments if not designed with care. Design engineers are challenged to find materials that can stand up to hydrometallurgical processes especially for copper, zinc, nickel, cobalt and uranium. This paper will evaluate material solutions to determine which provides attractive economics for initial procurement as well as high durability for reasonable life cycle costs.INTRODUCTIONMining activity in a number of metal ores has been running quite high over the last few years. In particular, those metals that employ acid functional extraction processes such as copper, nickel cobalt and uranium have been particularly active.The world’s largest nickel mine – the massive $4.76 billion Ambatovy nickel mine on the African island nation of Madagascar is nearing completion. When it reaches its full production capacity in 2013, the mine will produce 60,000 MT/yr of nickel and 5600 MT/yr of cobalt. Coming on the heels of the Ambatovy project is the Long Harbour Processing Plant in Newfoundland, Canada which will process the ore from Vale’s Voisey Bay mine in Labrador. Voisey’s Bay is expected to generate more than 50,000 MT/yr of nickel ore when it starts up in 2013. Next up will be the Boleo project in Mexico on the Baja peninsula. When commissioned in 2013, the $858 Million Boleo project is expected to produce 60,000 MT/yr copper, 3100 MT/yr cobalt, 36,000 MT/yr zinc and 100,000 – 250,000 MT/yr manganese carbonate.High nickel alloys and rubber lined steel have been used for decades to design corrosion resistant equipment for mineral processing environments. These materials demonstrate reasonable resistance to corrosion for most environments. Unfortunately, higher nickel alloys are quite expensive. Rubber lined steel is a bit more affordable but requires continuing service over time which ultimately drives up its cost as well. FRP (Fiberglass Reinforced Plastic) has also been used extensively in mineral processing for tanks, piping and ducting employed in aggressive environments. Today, more and more design engineers and material specifiers are calling for FRP composites for both new and replacement equipment used in the refining and processing of a variety of metal ores."

Jan 1, 2012

By E. Pallumbo, N. Szwedska, R. Asselin

"This paper highlights the results of collaboration between geology, mining and mineral processing teams during the restart of the North American Lithium Project, located near La Corne, Quebec, Canada. This collaboration was central in ensuring a cross discipline harmonization of design parameters and key inputs, all of which allowed for the development of an optimized life of mine plan suited to the particular needs of the operation.INTRODUCTION In July 2016, North American Lithium Inc. (NAL) began the process of restarting operations at the former Quebec Lithium Mine, located in the municipality of La Corne, Quebec, Canada. The North American Lithium Project (the Project) as it is known today, is the latest chapter in the history of this property. In order to provide a robust foundation for the project, multidisciplinary collaboration was instituted between the geology, mining and metallurgy teams. Despite the intrinsic link between these departments, in many instances their work is completed separate from one another; in silos. This collaboration highlighted specific drivers in the mining value chain that could be exploited to ensure that a saleable product could be produced effectively. This paper explores some of the concepts and strategies that were developed during the feasibility study that supported the project restart (excerpts from the study technical report have been used throughout this paper). PROJECT HISTORY In 1942, prospectors identified the presence of numerous spodumene-bearing pegmatite dykes on the Property. This led to additional interest and exploration drilling campaigns. In 1955, Quebec Lithium Corp. (QLC), who had acquired the property, began construction of an underground mine with mill facilities located on the surface. Operations began the following year at a production rate of 1,100 tonnes per day. A historical cross-section view of the underground mine is shown in Figure 1. In 1959, QLC began the construction of an on-site lithium refinery to produce lithium hydroxide. The refinery was finally operational by 1963. Mining and processing operations continued until 1966 when activities were halted due to a labour dispute. The property was sold and a few years later attempts to resume production were unsuccessful. Property ownership changed several times again until being acquired by Cambior in 1987. In the early 1990’s the existing mine and mill facilities were sold and the mine site rehabilitated"

Jan 1, 2019

By P. L. Drake

This paper comprises a discussion of the role which mineral resources will play in Canada's future export trade and the growing demand for minerals in Canada.

Jan 1, 1979

By W. Lin, Z. Z. Dong, C. L. Zhou, Y. C. Kuang

The inversion of rock mechanical properties based on well-logging data is a common method to drillbit selection in petroleum engineering, the basic principle of which is to use deep-well logging data and experimental regression model to calculate rock mechanical properties. The profile of rock mechanical properties can be established. According to the profile, the type of drillbit can be selected in different formations, which will improve the economic benefit of bit use indicators. Compressive strength of rock is one of the most important parameters. Conventional method to establish regression models of acoustic velocity and uniaxial compressive strength is on the basis of rock core sonic experiments and uniaxial compressive experiments. However, with the increase of deep drilling operation, triaxial compressive strength prediction model will play a more vital role in drillbit optimization selection in deep wells and improving ROP (Rate of Penetration). Triaxial compressive strength is an important parameter to evaluate the formation strength property. In this paper, to the sandstone commonly encountered in oil drilling, combined the rock mechanical experimental results with the changing porosity experimental results under confining pressure, a new interpretation model of triaxial compressive strength based on well logging data is proposed. Firstly, three types of sandstone samples are collected. Then measured components, uniaxial compressive strength, triaxial compressive strength and porosity. Experimental results show that: confining pressure has a significant influence on sandstone strength, with the increase of confining pressure, triaxial compressive strength increase; furthermore, the triaxial compressive strength of different porosity sandstones have different change rules when confining pressures changes; sandstone porosity decreases with the increase of confining pressure and it obeys logarithmic function. According to the results, regression models of sandstone, in-situ uniaxial compressive strength model and uniaxial compressive strength model under normal pressure are generated. Meanwhile, using well logging data in the acoustic velocity, density and gamma value can derive in-situ rock formations uniaxial compressive strength and in-situ porosity. Eventually, a new model established in this paper, containing in porosity, uniaxial compressive strength, lateral pressure and power exponent of regression, can predict triaxial compressive strength which will guide drillbit selection.

Jan 1, 2015

By S. D. A. Hannot, H. Knapp

"High pressure grinding rolls (HPGR’s) are an energy efficient solution for comminution of industrial minerals and metal ores. The technology is successfully applied in an expanding field of applications throughout the minerals industry. HPGR’s compress and grind the particle bed in the operating gap between two counter-rotating rolls. The equipment provides a high capacity, low energy alternative for applications with conventional tertiary and quaternary crushing and grinding, with size reduction reaching from 100mm down to 25 microns product. In this process, maintaining a controlled and evenly distributed operating pressure between the rolls is very important. Due to feed segregation, the pressure distribution along the roll’s length can become uneven, resulting in a coarser product. This paper will show that the best approach to compensate and adapt for the uneven pressure is to allow the rolls to skew relative to each other. Coarser products are also caused by an inadequate pressure distribution: the much-discussed edge effect. To minimise the consequence of the edge effect, an optimised ratio for the roll length to diameter will be calculated. Furthermore, the design philosophy behind a cheek plate will be detailed. This cheek plate is used to retain the material between the rolls, reducing the edge effect while still allowing roll skew. Together these design considerations help optimise HPGR’s performance.INTRODUCTION Initially developed for the cement industry during the energy crisis in the 1980’s , high pressure grinding has been an accepted technology for many years. It has been successfully implemented throughout the minerals industry, with applications in base and precious metals, as well as industrial minerals processing. The comminution process relies mainly on size reduction through to compression and inter-particle crushing in a particle bed in the operating gap between two counter-rotating rolls. The equipment typically has a high unit capacity and low energy consumption, and is increasingly used as an alternative to conventional tertiary and quaternary crushing and grinding, in particle size ranges reaching from 100mm down to 25 microns. It can be applied to moist ores and dry material, in open circuit arrangement or in a closed circuit with dry or wet classification (screening, air classification)."

Jan 1, 2019

By K. Gardner

"Many deposits have a geological model developed early in the project stages, which is not always reviewed or modified as the project matures and production commences. Conversely, ongoing pressures, due to a combination of declining head grades, a push for increased revenue and a multitude of other reasons, leads to processing plant modifications, with the primary aim being to increase production. Often, the ore deposit knowledge is not sustained or developed during the operational stages to the level carried out during the prefeasibility and feasibility study phases. This results in the variability within the deposit being poorly understood and a lack of data and knowledge being available to support (and ideally optimise) operations particularly in an environment where the flow sheet has changed and ore feed requirements are complex.INTRODUCTION This paper presents a case study of ore deposit knowledge development and corresponding process plant operating strategy at the Ladolam Gold Deposit, commonly referred to as the Lihir gold deposit in Papua New Guinea. The gold deposit is located in a tropical equatorial climate on the east side of Lihir Island in the New Ireland Province of Papua New Guinea. Gold mineralisation was discovered in 1982, and was followed by a major exploration campaign by a joint venture between Kennecott (Rio Tinto) and Nuigini Mining Limited. The first drillhole was drilled in 1983, and after an extensive period of drilling consisting of 343 holes for 83,500 m, the final Feasibility Study was completed in 1992. The feasibility study was based on a Reserve base of 37.9 Moz in refractory sulphide ore, with gold extraction proposed to occur via whole ore pressure oxidation due to the refractory nature of the mineralisation. The Lihir Special Mining Lease (SML) was granted in 1995 to a new PNG company – Lihir Gold Limited, and Rio Tinto established Lihir Management Company to develop and operate the mine on behalf of LGL. Mining and processing of the deposit commenced in 1997. Newcrest Mining Limited purchased Lihir Gold Limited in August 2010, and subsequently completed a major plant upgrade including the installation of additional grinding, autoclave and carbon-in-leach capacity. Post commissioning of the upgrade, Newcrest has continued to increase throughput and production. A reinvigorated ore body knowledge development program has significantly assisted this process in identifying operating strategies for the process plant and delivering recovery improvement projects to address declining head grade and recovery due to increased stockpile feed and flotation circuit use."

Jan 1, 2017

By D. M. Xue, T. B. Li

"With the increase of human engineering activities, global climate change and active plate tectonics movement, the giant landslide frequently occurred in southwest China, which caused huge property and human losses. Besides, the potential landslides pose severely threaten to the construction and operation of airports, railways, highways and power stations etc. In order to provide accurate guidance for the landslide investigation, stability analysis and mitigation, the giant landslide is redefined according to landslide volume, depth of slip surface, complexity of landslide mechanisms, and degree of landslide mitigation difficulty, and classified with the typological classification approach based on the twofold attributes of landslide behavior including formation mechanisms and reactivation features. Finally, the threefold particularity of the giant landslide is also summarized, which enables a more effective landslide mitigation design.INTRODUCTIONWith the increase of anthropogenic activities, global climate change and active plate tectonics movement such as continual uplifting of Qinghai-Tibet plateau and strong earthquakes, the occurrence of giant landslides was in ascending trend in southwest China (Huang, 2009), which caused serious destruction, and greatly endangers such engineering construction from safety, time and economic aspects as airports, railways, highways, power stations, etc. Giant landslides have huge scale, complex formation/reactivation mechanisms and mechanical behavior. They may not be identified during the hazard investigation, but may be firstly initiated or reactivated due to the following engineering activities, heavy rainfall or strong earthquakes. Consequently, the landslide mitigation is inevitable and costly. However, it is difficult to control the deformation of giant landslide with lack of a correct understanding of genetic mechanisms (Marui, 2012; Zhang, 2000) and the excessive large sliding forces of the slide blocks calculated by the conventional limit equilibrium method. For instance, the failure of anchored pile wall for the No.102 giant ancient landslide (Zhu et al., 2012) and stabilization measures for the Sidi Rached viaduct landslide(Guemache et al., 2011); four rows of piles had not prevented the occurrence of the No.12 landslide in a high fill slope in the Panzhihua airport (Li et al., 2012)."

Jan 1, 2015