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New Zealand depends on foreign investment for economic development. This also applies to the development of New Zealand's mineral resources. For this foreign investment to happen there must be some incentives to attract the investment. While prospectivity is the dominant parameter considered by investors it is not a variable that can be changed, only the perception of New Zealand's prospectivity. Other parameters likely to be considered are sovereign risk, red tape, green tape, land access, civil unrest, land claims, social risk, labour relations, infrastructure and natural disasters. Regulators and political will can vary some of these parameters. Where New Zealand fits internationally can be measured by investors' perceptions of these parameters. Following on from these perceptions New Zealand can be seen to have advantages in some areas and be disadvantaged in others. How to deal with the disadvantages to give investors confidence is not easy in the New Zealand environment where the development of mineral resources plays a small part in an economy dominated by agriculture. Added to this is the current global state of the minerals industry which offers even more of a challenge to attract foreign investment to develop New Zealand's mineral resources.

Jan 1, 2000

By L. H. DeWald

During the examination of various commercial brands of copper wire bars, which had exhibited different degrees of adaptability for being drawn into fine gages of wire by the present-day high speed machine, it was found that each brand had a more or less characteristic crystal macrostructure. The extremes of these macrostructures are similar FIG. 1.-EFFECT OF METAL TEMPERATURE IN CASTING ON CRYSTAL MACROSTRUCTURE OF BAR. Reading from left to right, metal temperatures were 1166" C., 1149" C., 1132" C.. 1121" C., 1093" C. to the maximum variation shown in the photomacrographs reproduced in Fig. 1. As the various brands did not differ materially in chemical composition, it was concluded that the differences in structure were the result of variations in casting technique.

Jan 1, 1931

By K. Saito, Y. Miyauchi, T. Nishi, Y. Kizu

At Tokushima Plant of Nippon Denko Co., Ltd. high-carbon ferromanganese is produced by the electric furnace method using lump manganese ores and sintered manganese ores manufactured from fine manganese ores. However, the distribution of manganese ores is significantly uneven on earth, and their characteristics considerably vary by ore type. It is known from experience that the production of high-carbon ferromanganese by the electric furnace method depends greatly on material ores. Therefore, to maintain stable operation in the electric furnace-smelting field, it is important to identify the characteristics of each type of material ores in advance. Thus, we evaluated the high-temperature electric characteristics of manganese ores using the electrical conductivity measuring system developed by ourselves and provided the standards for determining ores and blending ratio necessary for stable operation of the electric furnace based on the evaluation results. This time we worked for optimisation of the high-temperature electric characteristics of sintered manganese ores through modification of the characteristics because the blending ratio of sintered manganese ores in the electric furnace is high. The electrical conductivity of sintered ores having various chemical components in a high-temperature region (up to 1 550°C) was measured using our electrical conductivity measuring system and high-temperature electric characteristics evaluating method reported at INFACON 9. As the result of the measurement, we revealed that the high-temperature electric characteristics of the sintered ores depend on their chemical contents and the sintered ores can be modified to those having excellent high-temperature electric characteristics by controlling their chemical contents, so that the resources can be effectively used.

Jan 1, 2004

By Italo Onederra, Jason Furtney, Ewan Sellers

The detonation reactions occurring during rock blasting result in high pressure gas phase products from the condensed explosives typically used in mining applications. After detonation and the initial fracturing, the work done by the expansion of this gas contributes to burden movement and further rock fracturing. Before all of the energy in the reaction product can do useful work on the rock, some of this energy is lost to crushing and possibly to gas venting to the atmosphere. Borehole gas pressure decreases by three principle mechanisms: (i) expansion of the borehole cavity, (ii) flow into the fracture network, and (iii) flow through the stemming. To simplify the problem and to get a better understanding of the interaction of these mechanisms, a simple model for each of these mechanisms is developed. A comparison is made of the time-scales and the influence on burden movement for each. A comparison of gas flow behavior is made between typical ANFO and emulsion products.

Jan 1, 2012

"Increasing demand for timely and accurate information about flotation plant performance requires metal accountants to increase the scope and reporting frequency of plant production. This trend has brought in-process inventory estimation at the forefront of metal accounting issues. Such significant in-process inventories can be locked in diverse process equipment (bins, holding tanks, flotation cells, thickeners, pipeline, etc.) or in stockpiles (ore, concentrates, tailings, etc.). Practice has shown that boldly ignoring these in-process inventories or the errors associated with their estimation lead to unreliable metal balances thereby creating confusion in plant production planning and operational performance assessment. To this extent, the characteristics (physical bounds, spatial heterogeneity and residence time) as well as the available measurements (volume, density, humidity, mass, composition, etc.) of each unit/section found in a generic flotation plant are jointly reviewed with respect to the particular metal accounting issues they present. The daily and monthly metal accounting tasks are then reviewed together with possible methods for obtaining reliable inventory estimates including different procedures for end-of month reconciliation.INTRODUCTION Most of the cost reduction initiatives of the mining industry aim at improving capital efficiency and asset utilization. Among the possible paths through which these goals can be achieved are mine-to-metal optimization, real-time plantwide process control (Hodouin, 2011) and knowledge sharing databases (Bascur & Linares, 2006). However, the successful implementation and subsequent monitoring will ineluctably results in an increased demand for timely and accurate information. This more than often requires metal accountants to increase the scope and reporting frequency of plant metal production. A striking example of such scope expansion is the Minas-Rio iron ore project in Brazil (Anglo American, 2013) having a pipeline route of 525 km between the concentrator and the concentrate shipping area. Several other mining companies have also set an increased frequency for their key performance indicators thereby shrinking the metal accounting period from monthly to weekly and daily. Those concurrent trends have brought in-process inventory estimation at the forefront of metal accounting issues. Indeed, as illustrated in Figure 1, improving trading reactivity requires improvements in production planning which strongly impacts the requirements for reliable metallurgical accounting. Furthermore, practice has shown that boldly ignoring significant in-process inventories or the errors associated with their estimation can lead to unreliable metal balances. In other words, since metal balances are the cornerstones of metal accounting, some of the risks associated with important business decisions are linked to errors associated with in-process inventory measurements."

Jan 1, 2014

By Kerry Spickelmier

Editor's note: information for this feature was taken from the published APCOM proceedings. Computer trends, with special focus on the reasons for computer use, grabbed the lion's share of attention at the 23rd worldwide meeting on the Application of Computers and Operations Research in the Mineral Industry (APCOM 23). However, technical topics did not provide the meeting's sole focus. The last-minute inability of certain former communist countries to fund the travels of a few scheduled speakers was a reminder that science does not operate in a void. As with all technical progress, the APCOM presentations raised interesting questions regarding interrelated organizational dynamics and political and socioeconomic issues. Consider US Bureau of Mines (USBM) research to design an expert control systems to "duplicate" an experienced, "good" operator during automated underground roof bolting. In his presentation of the project, Takach, Jr. stressed the importance of preserving the ability to switch from automatic to manual drilling control. From a technical standpoint, this allows the expert system to "learn" from a good operator. As important, he said, is that this flexibility decreases the human operator's sense of being replaced by the machine. The question arises: Which will loom larger in union minds, increased operator safety through remote opera¬tion or the potential for total operator replacement? Like any new product, computer technology relies on marketing to aid its acceptance and use. Consider, too, a decision support system, by Schena and Gochin, for mineral resource management in a developing country. The authors said "the analysis permits the assessment of the overall socioeconomic consequences of mineral prospects and allows incorpo-

Jan 1, 1992

By D. A. Reynolds, J. D. Davis

"INTRODUDTION Investigations by the Bureau of Mines have shown that the carbonizing properties of splint and bright coals may differ greatly. In a study of 55 coal columns selected from representative coals of the Appalachian region, Sprunk and coworkers 10/ compared various chemical and physical properties of splint and associated bright coals. Carbonization tests in the Fischer retort at 932°F. (500°C.) showed that, except for bright coals of high oxygen content, the coke residue from bright coal was much more swollen and cellular than that from splint. ·with one exception, agglutinating values determined by the Bureau of Mines test, were lower for splint than for associated bright coal.Because sorting of coal in quantity is tedious and time-consuming, separate types have not been carbonized by the Bureau of Mines-American Gas Association (BM-AGA) test, which requires 85- to 200 pound charges. However, this method has been used to determine the carbonizing properties of samples 0f bed layers that are composed largely of either splint or bright coal.4/ In these earlier tests, which were made at high temperatures on layer samples from the Elkhorn bed, Letcher County, Ky., the splint coal yielded more coke than the bright coal, and this coke was slightly stronger than that from the bright coal. The cokes from samples with large proportions of bright coal were more cellular or porous, as were the low-temperature cokes obtained from carbonization of separated samples of bright coal in the Fischer retort."

Apr 1, 1944

By Christian Roche

Our study is focused on the sub-assembly con-tact shoes, pressure rings and pressure bellows. We were keen to mainly study [ ] 1.The contact shoe design 2.The most efficient pressure to ensure an optimal electrical contact between the contact pad itself and the casing 3. The contact shoe cooling circuit in view to provide to the shoe the best mechanical and electrical characteristics in order to bring to the users of COFOR® components a new standard in process setting technical solutions. A finite elements simulation, combined with a thermal and structural studies were used. Our presentation which follows is dedicated exclusively on the influence of the contact shoe cooling system on the process through a thermal and structural analysis. [ ]

Jan 1, 2007

By L Tolmay, L Nair

Investor confidence can be compromised when one observes large discrepancies between the SAMREC reserves and the mining plan. It is therefore up to the responsible persons to ensure that all contributing factors get taken into account when determining a reserve declaration. Confounding factors could be further aggravated by large oscillations in the commodity price thus resulting in major changes to the mining plan, if the accepted price was either too optimistic or pessimistic. Additional factors that must receive our attention are, uncertainty in geological facies type, mining practices, geology and grade estimation. The paper outlines (in the authors? opinion) some of the important factors that need to be taken into account, in order to ensure proper alignment between the estimates of the life of mine (LOM) reserve grades, and the corresponding actualisation of the mining plan. These parameters provide an historical insight into what actually happens when attempts are made to implement the mining envisaged in the LOM plan. In turn these allow judicious application of discount factors that enable a realistic estimate of SAMREC reserve classification and declaration. Some of the factors that will be covered are: - 1) Flexibility of developed reserves and the ability to maintain this. 2) Mining control mechanisms and their overall efficacy. 3) The ability to extrapolate facies types and its effect on grade control. 4) The ability to control the mining mix and value variation. 5) Finding a happy medium between optimism and pragmatism.

Jan 1, 2007

By M. Gallego, R. Oyarzun, L. Ortega

Evidence of metallogenic activity in an area dominated by Upper Precambrian and Palaeozoic metasediments was partially explained in the 1980s when drilling and a geophysical survey detected hidden intrusions, but questions remained to be answered about the nature of the fluids. Sb mineralisation at El Juncalon vein-type deposit was selected for geological, geochemical and fluid inclusion studies as a model with a relatively simple quartz-stibnite-pyrite paragenesis. Many of the characteristics were those of Chinese-type vein Sb deposits, which can be regarded as atypical of the epithermal type as they are hosted by clastic rocks

Aug 1, 1995

By O. A. Bascur, J. Patrick. Kennedy

"The lack of integration of mining and metallurgical information at sufficient detail to act is a problem. Without such data, mine cut-off grade can not be optimized on a per grade basis. It is difficult to determine economics without integration of mine transactions, stockpile inventories, process flows and assays. Actions also require real time information from manufacturing assets, but corrected for gross errors from trucks, shovels, conveyors, faulty sensors, bad instrument calibration. Validation methods must include process models to identify corrupt actionable information. This paper presents new tools that use the model the process to sift through available data, identify and eliminate gross errors, and use statistical data reconciliation to create material balanced, internally consistent values. Uses of models allow data to be unified for useby both monitoring and decision making processes.A Real Time Performance Management (RtPM) uses unifying analysis methods to empower everyone in the organization with unparallel real-time intelligence, enabling them to continuously improve performance.BACKGROUNDExtraction of metals has become a global business; new economic and environmental forcing factors are present today which were unheard a couple of years ago that are causing companies to focus on plant operations. High ROI actions can be achieved internally which will increase mining and metallurgical processing unit efficiency and reducing operating costs if the proper information is provided those in the complex that can act. Large changes are possible with many of these small steps if the barriers for action are removed. The chief impediments are lack of infrastructure including the data, computing tools and essential data and bad information.Increased demands will be placed on the types, quantity and priority of information. Metallurgical complexes are attempting to become better neighbors, increase productivity, improve customer service, and satisfy the regulators and compliance groups -- all with fewer people and less costs."

Jan 1, 2004

By M Cooper

Since its enactment in 1991, the Resource Management Act (RMA) has generated both praise and criticism. The major criticism is in relation to the costs the Act poses to industry and the time it takes to work through the process. In response to such criticisms the Minister for the Environment has initiated a review of the implementation of the RMA. The Minister's proposals for reform have not yet been released and the discussion that follows is based upon the report by the Minister's Review Group which was released in September.

Jan 1, 1998

Coal bursts are one of the least understood yet the most critical hazards in underground coal mines. The ground motions induced by seismic events can trigger unstable failure of coal and rock mass and degrade the surroundings of an excavation. Therefore, the characteristics of ground motions should be fully investigated for an improved burst risk management. This paper analyzes ground motion features of a longwall panel from a typical underground burst-prone coal mine in China. The results showed that most of the ground motions on roadways were hardly initiate coal bursts due to insignificant energy input to the damage. The intensity of ground motions in near-field zone were nearly 20 times higher than those in far-field zone. The strongest vibration on roadway was induced by a coal burst with energy of 28,600 kJ, which can cause ground motion of 0.77 m/s and equivalent dynamic stress of 14.69 MPa. The findings of this paper can improve the assessment of seismic risks and its management.

Jan 7, 2020

By Claude MacDonald, John H. Ashburn

"IntroductionIndustrial growth and technological change over recent years had been accompanied by two major sources of concern to management and employees: (a) increase in occupational injury and illness and the resultant costs involved; and (b) equipment damage and breakdowns in concentrated production lines causing more extensive loss potential.Due to economic factors, management attention has focussed more on production and quality than on safety, health and related loss potential sources. As a result , occupational safety and health activism has grown, government legislation of compensation and occupational safety and health standards have progressively developed and stronger liability attitudes have been taken by courts of law.To improve efficiency and allow development in more competitive markets, rising labour costs, equipment costs and safety related financial losses have dictated that attention be given to conservation of all resources. Conservation of resources, people, equipment, material and environment, can no longer be addressed in isolation but must be managed integrally with production and quality. To this end, systems have developed utilizing sound management principles applied with equal intensity to production, quality and loss potential"

Jan 1, 1987

By K. L. C. Gonçalves, V. K. Alves

"CVRD’s Department of Development and Technology – GETEK has been developing and perfecting a general methodology for scaling up flotation and grinding circuits over several years. This methodology has been applied in several prospective CVRD mining projects. It encompasses a procedure for variability analysis based on bench scale tests, pilot scale grinding and flotation tests and modeling and simulation for scaling up the industrial flowsheet.The bench scale tests include the determination of the Work Index, simplified DWT tests, rougher flotation and locked-cycle tests with samples that are representative of the ore body variability. After completion of these studies, continuous, pilot-scale flotation tests are carried out at a Mini Pilot Plant with drill core samples representative of different stages of the mine life. Finally, studies are carried out with large volume samples using a conventional grinding and flotation pilot plant. This sample is also used for liberation characterization, grinding kinetics, flotation kinetics and industrial circuit scale up. This methodology has been successfully employed in the development of CVRD’s new mining projectINTRODUCTIONCVRD has been developing and perfecting a general methodology for scaling up flotation and grinding circuits over several years. The definition of the processing route and the sizing and scale up of the processing system are some of the products generated during the pre-feasibility of a greenfield project. This paper is focused on the scale up of grinding and flotation circuits, operations known to be of the most importance in a mineral processing plant.The methodology for the definition of the flotation and grinding circuits is divided in the following stages: bench scale ore variability studies, pilot plant operation and modeling followed by simulation. The product of this work is a calibrated simulator that can be utilized for plant operation as well as mine planning, looking to achieve optimal operational conditions.The current models used for scale up of the grinding circuits are aimed at the generating information about the size distribution of the circuit product. However, it is well known that the liberation state of these products may be of critical importance for the performance of the concentration processes downstream. Nevertheless, CVRD has been developing a methodology for liberation kinetics during grinding, aimed at optimizing grinding circuit throughput together with downstream flotation recovery."

Jan 1, 2006

By J. Drelich, C. L. White, Ch. Zhou, W. M. Cross, E. T. Zellers, E. M. Nadorny

A laser-based particle deposition (LBPD) technique has recently been developed at Michigan Technological University for patterning mesostructures made of nanoparticles and their clusters. The LBPD technique makes use of laser induced optical forces to transport and pattern nanoparticles on a variety of conductive and non-conductive substrates from nanoparticle-in-liquid suspension. A weakly focused laser beam is used to confine and propel particles along the laser beam. Confinement is accomplished by forces due to optical field gradients that act on polarizable particles and tend to move them to axis of the laser beam. The force propelling the particles along the direction of the laser beam arise from momentum conservation of photons scattered from the particles. In this paper, this novel LBPD technology is briefly reviewed, and several examples of patterning are presented. The size and morphology of mesostrips produced from gold and polystyrene nanoparticles, under a range of deposition conditions, have been characterized by optical microscopy, atomic force microscopy, and scanning electron microscopy. The results presented here demonstrate that gold and polystyrene nanoparticles deposited by LBPD can form clusters of particles. When deposited at an appropriate rate, such clusters can form multilayer mesostrips of high particle density. One goal of research on such systems is to fabricate arrays of parallel lines made up of colloidal particles having a range of surface functionalities. Such arrays have potential for application as novel microsensors for environmental sensors.

Jan 1, 2003

By Stephen C. Tadolini, Thomas E. Marshall, Cecil Banta, L. J. Prosser, Anthony T. Iannacchione

The Pittsburgh Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) endeavors to provide national and world leadership in the prevention of work-related illness, injury, and death. This is accomplished by using a scientific approach to gather information, assemble and create knowledge, then translate the knowledge and results into products and services. These products and services are then delivered to all personnel who can effect prevention. Obviously, the development and use of instruments to monitor mine roof conditions provides an opportunity to execute that mission. In the late 1990’s, based on observations at a number of underground limestone mines, only a few used roof monitors. Subsequently, NIOSH introduced the Roof Monitoring Safety System (RMSS) as an aid to roof inspection beyond traditional visual and sounding techniques. Initial expectations were that by gaining roof movement information, ultimately roof sag rates could provide indications of eventual failure. During this investigation, RMSSs were installed in 13 underground limestone mines in six states and this paper analyzes the data obtained at three of these mines. This paper also provides an overview of the system, data, analysis, and applications relevant to the RMSS.

By Bruno Gemmi

A new warehouse built with prefabricated components over an area underlined by soft marine soil deposits started showing differential settlements well before its completion. Its 103 spread footings carrying up to 4,000kN (450t) axial loads had been cast on jet-grouted columns extending and penetrating a layer of sand at a depth of 10m (33ft). Investigations performed to assess the wholeness and consistency of the jet-grouted columns revealed a state of loose jet-grouted masses and uncontrolled, off target migrations of the jet-grouting. Most of the jet-grouting itself was settling. The following remedial solutions were suggested: 1. Construction of new and better controlled jet-grouted columns. 2. Cement-based soil grouting. 3. Expanding resin injections. 4. Minipiles drilled-through the existing footings and reaching into a denser layer of sand existing at 23m below grade. Remedial solution 1. was immediately discarded due to cost and the possibility of a repeating failure in this non-granular and highly compressible soil. Tests of remedial solutions 2. and 3. were carried out. The outcome of the grouting was monitored by Electro Resistivity Tomography (ERT) (Bares et al., 2003), an innovative 3D electro tomography procedure showing where grout had been actually placed and its migrations off target. A successful 4,000kN (450t) load tests confirmed the validity of the solution. Finally, upon the completion of a successful load test, solution 4. was chosen. It supplied the highest degree of reliability thanks to the ease of controlling the final and actual location of the minipiles and to the higher safety factor provided. All remedial work to install the minipiles was eventually performed inside the building. Additional load tests and settlement measurements confirmed the adequacy and success of the chosen solution.

Jan 1, 2011

By Foster Fraas

One of the lithium minerals most widespread in the earth's surface is spodumene (Li2O-A1203-4Si02) a lithium aluminium silicate. For some time, deposits of this mineral were known to exist in the Black Rills of South Dakota, but it was only quite recently that Hess4/ pointed out the great magnitude of the low-grade e deposits it s in North Carolina. The theoretical lithia (Li20) content of spodumene is 8.04 percent. The only other minerals with such high lithia content are the phosphates, but these occur only in pockets and are not in extensive deposits5/. Actually, however, the lithia content in spodumene is never found to be this high, being nearly always below 7 percent for the pure mineral, and part of the lithia is apparently replaced by other alkalies.

Jan 1, 1937

By S. P. Pearton

"Pumpable emulsion explosives have been available to surface and underground massive mining operations for decades, and their unique properties offer significant advantages in terms of improved safety, reliability, and performance. However, the benefits of pumpable emulsions have been unavailable to narrow-reef mining operations due to the lack of technology necessary for their successful implementation in this challenging environment. Despite efforts to promote and enhance the safety and performance of bulk emulsions for narrow-reef stoping, little research has been undertaken to advance the pump technologies required for their implementation. This has resulted in a gap in knowledge and technology, and as a consequence the successful implementation of a pumpable emulsion system has consistently eluded the narrow-reef environment.The purpose of the following investigation was to evaluate the viability of pumpable emulsion explosives for use in South African narrow-reef mining operations. By approaching the problem from multiple perspectives, this research aimed firstly to propose a theoretical framework and suite of equipment suitable for the implementation of pumpable emulsions within the narrow-reef environment. Through the development of this suite of pumpable emulsion technology, tests could be undertaken on the proposed narrow-reef emulsion formulation and pumpable emulsion technology to obtain the necessary understanding of the performance of the system under controlled operating conditions prior to its implementation in the broader mining industry."

Jan 1, 2015