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A wide range of drill holes and process streams are sampled for resource estimation, grade control, and contractual purposes in the minerals industry. However, despite the availability of training courses, conferences and both national and international standards on correct sampling practices, it is still surprising how often little attention is given to ensuring that representative samples are collected for analysis. The reason for this is that the responsibility for sampling is often entrusted to personnel who do not appreciate the significance and importance of sampling, with cost being the main driving force rather than whether the sample is representative of the material from which it was extracted. This seriously undermines the precision and accuracy of the analyses subsequently generated and can render the analysis process a total waste of time and money and expose mining companies to serious, potential, financial losses. Company management needs to reverse this situation and ensure that sampling is given the attention it deserves to generate representative samples for analysis.

Jan 1, 2010

By S. Schade, G. Möllemann, C. Niestroj

"Mining environments, whether open-pit or underground, pose difficult conditions for any sensor system. However, the ever-increasing need for automation requires the application and use of sensor systems in order to gather relevant information required for process automation. Ultra-Wideband radio (UWB) is a robust technology well-suited for underground applications. These applications include positioning and communication. This paper introduces UWB and presents results from measurement campaigns in harsh environments. Using filtering and sensor fusion precise and robust positioning can be achieved even in confinements of underground mining environments. INTRODUCTION Indoor positioning systems (IPS) are gaining ever more importance. Especially in light of ongoing efforts to reach the goals of what was coined as Industry 4.0 by the German government, the development of IPS is inevitable. According to a recent report about the “Global Indoor Location Market Outlook 2019” a growth from $ 597 million in 2014 to $ 3961.8 million by 2019 is expected [1]. Hence, there is also an economic incentive to pursue this topic. The mining industry is profiting from this development as well, since IPS are the basis for the automation of especially mobile mining equipment. Ideally, indoor positioning systems offer to position the equipment continuously and, what’s more, even in real-time [2]. Different approaches are available for IPS. The difference of these systems lie in terms of accuracy, cost, precision, technology, scalability, robustness and security. [3] At the Institute of Advanced Mining Technologies (AMT) of RWTH Aachen University, research suggests that one of the more auspicious approaches for IPS in the mining sector is the employment of ultra-wideband (UWB) radio technology. Because of this, there has been ongoing research into the best way to introduce UWB technology for the application in underground environments. The research started with an indoor positioning application, which only consisted of the UWB system. In the course of this, different algorithms were developed to enhance the system’s performance for the use in the mining industry. This led to the idea of sensor fusion in which the information of the UWB system are combined with infrastructure-independent technologies like inertial navigation systems (INS) and image-based technologies."

Jan 1, 2017

By Robert E. McIvor

"The design/optimization of the pump and cyclones to maximize grinding circuit efficiency first requires a concise understanding of, and clearly defined specifications for, desired grinding circuit performance. Subsequently, the pump and cyclone performances that provide the desired grinding circuit performance can be defined. Once the performance requirements of each process unit are determined, selection of physical equipment parameters that will deliver those performances can be carried out.The Functional Performance Equation shows that there are two distinct efficiencies in closed circuit ball milling. One of these, “Circuit Classification System Efficiency” (CSE), is the fraction of “coarse” material inside the ball mill upon which grinding energy is deliberately expended, versus the remaining fraction of “fines” or finished size material inside the mill, upon which grinding energy is wasted (on over-grinding). The role of the pump and cyclones is to maximize CSE, which is the desired grinding circuit performance. The obtainable target CSE for any given circuit can be estimated, for example, by referring to a plant data base of CSE’s. Design/optimization guidelines then allow us to specify the pump and cyclone performances that will achieve the target CSE.This paper outlines the step-by-step, systematic method of pump and cyclone selection which maximizes CSE. Numerous examples of its successful application are provided.THE FUNCTIONAL PERFORMANCE EQUATIONObservation of the feed and product size distributions going into and discharging from the mill in grinding circuits with low versus high circulating load ratios initially led to the definition of “Circuit Classification System Efficiency” (or CSE, McIvor, 1988a), and subsequently the discovery of the Functional Performance Equation (McIvor, 1988b; McIvor et al, 1992). The CSE is the fraction or percentage of “coarse” (usually in reference to the plus P80) size material inside the mill, versus “fines” or product size material finer than the circuit P80. It can be readily calculated by taking the average of the percentage of said coarse material in the mill feed and mill discharge streams. As this also represents the percentage of the mill energy expended on targeted, coarse size material, it is directly proportional to overall grinding circuit efficiency and production rate. This is all clearly expressed in the Functional Performance Equation for ball milling circuits, for which the derivation has often been presented (e.g. McIvor, 2006)."

Jan 1, 2011

SOME notes on the works of the Electrolytic Refining and Smelting Company of Australia will no doubt be of interest to members of the Institute, more especially as much of the work is new to Australasia. As many of the members who may read this paper have not been in a position to visit works of this kind, and are consequently not thoroughly acquainted with all the operations carried on, the author has taken the liberty, in some cases, to enter into explanation which would otherwise be unnecessary. The works are situated at Port Kembla (New South Wales), about fifty miles south of Sydney, and are approachable both by rail and water. The Government has recently built a low-level jetty upwards of five hundred feet long, and intends installing at an early date an electrically operated portable crane to facilitate the handling of material to and from the boats. This will mean: a considerable reduction in the length of time that boats are laid up at the jetty. There are also under construction two breakwaters, which, when complete, will materially assist shipping operation...

Jan 1, 1910

By Jana Dobrovska

The paper deals with new approach for measurement and evaluation of chemical microheterogeneity of elements in polycomponent metallic systems (i. e. steels, Ni-alloys). The method is based on the original mathematical model for determination of distribution curves of dendritic segregation of selected elements and on the original mathematical model for determination of the effective partition coefficients of these elements in the structure of analyzed alloy. Application of the method at research of chemical heterogeneity of continuously cast steel slab is also presented. The original results of measurement of dendritic microheterogeneity of eight elements (Al, Si, P, S, Ti, Cr, Mn and Fe) in structure of nine zones of a transversal section of slab are given.

Jan 1, 2006

By A Giblett, K Afewu

This paper uses a case study to demonstrate best practices techniques for predicting the contribution of gravity concentration in a gold recovery process flowsheet. The case study was selected as an example of an ore with a marginal gravity gold content, which makes the value of a gravity circuit difficult to quantify. In this instance the value of leveraging a significant knowledgebase of operating gravity circuit performance to support the decision making process was demonstrated. This case study analysis serves as a useful demonstration of best practice methodologies supporting decisions to include or exclude gravity recovery in a gold recovery process flowsheet.CITATION:Giblett, A and Afewu, K, 2015. Do we need a gravity circuit or not? A case study in applying best practice, in Proceedings MetPlant 2015, pp 288–295 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By D. Harrington

Educational campaigns conducted by the manufacturers of explosives, the Bureau of Mines, mining companies, and safety organizations have contributed greatly in reducing accidents caused by explosives arid blasting. Despite these campaigns and the dissemination of information, accidents from explosives and blasting continue to be the direct cause of scores of fatalities and hundreds of nonfatal accidents annually, not only in the mineral industry but essentially wherever explosives are used. The experience of many mining companies and other users of explosives has proved that accidents from explosives can be prevented or averted by the proper training of employees in the handling and using of explosives and by the enforcement of definite rules and instructions for their use. Unfortunately, throughout the years numerous false impressions and ideas have grown up and around the use of explosives. Many of these can be traced back to the manner in which the users of explosives were originally taught, if instructed at all; and as with many types of misinformation in nearly all walks of life, those false ideas are decidedly persistent and being so cause much damage. Many if not most of the users of explosives gained their knowledge of explosives and blasting by watching others and more or less "absorbing" the procedures and thrones of the other fellow, who acted unconsciously as teacher or instructor. A study of explosives accidents reveals the results of such "teachings" when the causes of the accidents are determined, and as might be expected the results very often are far from good. One of the most persistently erroneous impressions or ideas is concerned with the burning rate of safety fuse. Many men with

Jan 1, 1944

By Zhang Chuanfu

Keywords: modified coprecipitation method, Ni-Co alloy powders, solid-solution oxalate, growth mechanism Homogeneous solid-solution oxalates of Ni2+ and Co2+ ions were synthesized by modified coprecipitation method and the composition and morphology of the fibrous solid-solution oxalates precursor were characterized by XRD, IR, DTA/TG and SEM analysis. The effects of feeding methods, pH values, precipitation temperature, reactant concentration, addition surfactant, alcohol washing and drying process on the morphology and dispersion of the precursor were investigated in detail. The experimental results showed that the coprecipitated powders have characteristics that are different from those of the mechanical mixtures with the same stoichiometry. Based on the observations of precursors growth and SEM morphology of the precursor, the oriented attachment was proposed for the well-aligned growth of the fibrous Ni-Co alloy precursor particles.

Jan 1, 2005

By Anne Kvithyld

Silicon solar cells, that convert the energy of sunlight into electric energy, are attractive sources of energy. In the production line wafers of solar cells are sliced from a multicrystaline ingot solidified unidirectionally. Recycling scrap from top and sides of such ingots is addressed. SiC and Si3N4 inclusions are a major problem. Scrap from Scan Wafer ASA is melted in a high vacuum furnace at around 1500ºC. The filters, from commercial producers, are C and SiC with 10, 20 and 30 ppi. Characterisation of inclusions before and after filtration, and in the filter itself, is performed by microscopy. Dissolution of silicon in acid and counting of the un-dissolved inclusions is also carried out. In the filter Si3N4 needles and SiC inclusions were identified. The amount of these inclusions in the filtered silicon is much less than in the input. In conclusion, filtration using SiC and C filters in vacuum system in argon atmosphere removes SiC and Si3N4 inclusions from solar cell scrap. Flow of metal through the filters is not a problem. These results are promising with scale-up to industrial application in mind.

Jan 1, 2006

By Yves-Laurent Turcotte

Notre conférencier, Monsieur Yves L. Turcotte, Vice-président et Directeur général chez Promaintech Novaxa est diplômé en génie industriel de l?Université du Québec à Trois-Rivières et détient une maîtrise en gestion de projets de l?Université du Québec à Montréal. Il est une véritable sommité canadienne dans le domaine de l?amélioration de la performance des organisations. Provenant d'entreprises manufacturières et de services, il possède plus de 20 ans d?expérience en tant que développeur de technologies, conseiller et formateur auprès d?entreprises. Il a à son actif la réalisation de mandats dans plus de 400 entreprises. Il est reconnu pour sa grande capacité d?analyse et pour trouver des solutions novatrices et profitables aux problèmes des organisations les plus complexes. Aujourd'hui, il dirige Promaintech Novaxa, une division de DMR, qui a célébré son dixième anniversaire en 2006. Cette organisation ayant des places d?affaires dans la région de Montréal, Québec et Vancouver compte plus de 50 professionnels et a une carte de visite dans 16 pays. Les axes d?intervention sont le Management, la Productivité, la Fiabilité, l?Innovation et l?Amélioration Continue.

Feb 1, 2008

By A. J. MacRae

Metallurgical furnaces are made up of complex multi-component systems that must function either together or in parallel for safe, and reliable operation. Thermal expansion of single material components experience induced stresses during heating and cooling, which can lead to cracking or failure. Multi component elements and systems can experience significant thermally induced stresses during both steady state and transient temperature conditions. Examples pertaining to temperature effects on refractory, copper cooling blocks, furnace shells, and complete systems will be discussed. The purpose of the paper is to highlight how stresses and strains are developed due to differential thermal expansion.

Jan 1, 2015

By Anibal Gastañaga

La determinación del cuarzo es un problema dentro de la Higiene Industrial, puesto que este mineral se convierte en una de las enfermedades ocupacionales causadas por la inhalación de pequeñas partículas de cuarzo encontradas en el aire. En ese sentido, el presente texto señala la importancia y peligrosidad de los polvos del mineral a través de la determinación cuantitativa de cuarzo en los polvos industriales, ya que el riesgo de adquirir silicosis es proporcional a la concentración de cuarzo en los polvos ambientales. Existen tres métodos para la determinación cuantitativa de cuarzo: El método químico, el de difracción de rayos X y el petrográfico. El método que presenta mejores beneficios es el de N. A. Talvitie, puesto que se basa en la propiedad del ácido fosfórico, donde se forma complejos solubles en agua con los silicatos y óxidos metálicos, quedando el cuarzo prácticamente inalterado.

Aug 1, 1955

By Thomas A. Milne

As part of the broad program to improve the safety of underground coal mines, the Pittsburgh Mining and Safety Research Center sponsored several detailed studies on the inhibition of coal dust-air explosions. The present study was one of these. The goal of the research was to advance the development of improved coal-dust explosion inhibiting agents by determining, on a laboratory scale, the basic chemical processes involved in the inhibition of coal-dust flames by dry-powder agents. B. Our Approach Neither the basic molecular processes involved in coal combustion, nor the molecular mode of action of dry-powder agents, are known with certainty. Our approach, therefore, involved the direct determination, by sampling techniques, of species behavior in small, aerodynamically simple flames. To further aid in separating behavior of coal and dry-powder inhibitors, the latter were studied in CH4-air flames.

Jan 1, 1976

By Kirstin Girdner, Tom BoBo, Brian Norton, John Kemeny

Split Engineering is a truly customer oriented company dedicated to providing quantified fragmentation information of the highest integrity to enable process management and control. Technical decisions, blasting costs, operational efficiency and productivity and equipment performance can all be related to optimum fragmentation. In the past, the lack of an easy, non-disruptive, economical measuring technique has meant that, in most cases, rock fragmentation has not been defined in quantitative terms. Now, the Split-Desktop@ software provides an economical alternative to manual sampling and screening and an objective measure rather than subjective qualitative estimates. This workshop will present the latest features of the Split-Desktop@ software and show users how to quickly get quantifiable results from their blast fragmentation. A step-by-step demonstration will display the software’s flexibility, user-friendly options, and ease of use. Outlining where other mines have benefited from using the Split-Desktop@ software will provide insight to a wide range of software uses and potential applications like creating a database of geologic zone specific post-blast fragmentation information, underground draw point monitoring, stockpile, leach pile, and waste dump size measurement and monitoring, as well as many other applications.

Jan 1, 2000

The polymerisation of silica is found to interfere with thickening of leach pulps at Risdon. Hydroxyl ion and fluoride ion are catalysts for this reaction. Stability may be obtained by the presence of aluminium or ferric iron.INTRODUCTIONAt Risdon it has been a matter for satisfaction that, although the concentration, of silica in leach solutions is appreciable, it has ,given relatively little cause for anxiety.However the margin of safety is small and some intermittent difficulty in thickening leach residues during the last few years has prompted a further investigation, certain parts of which are described here since they may be of general interest.Leaching and ClassificationThe method of leaching which is practised at Risdon has been described in, two previous articles, by W. C. Snow (1936) and S. W. Ross (1949) to whiCh the reader is referred for detail. Continuous leaching is practised, the circuit solution flowing through five air agitated pachucas in series, to tlie first of which calcine is added. The circuit solution, which also enters the first pachuca, consists of spent electrolyte from, the electrolytic cells and contains 90 -gm. of free sulphuric acid per litre. About 80 per cent of the solublezinc oxide is extracted from the calcine in the first pachuca, at a pH value of 1-1 (7 gm.H2S04/1 at 55 to 60°C. In the later pachucas the leaching rate decreases sharply. The leach pulp which leaves the 'last pachuca contains an average of 17 gm. of free acid per litre, corresponding to a pH of 1.7; but, owing to variations in extraction, the end point fluctuates between 2.5 and 0·3 gm. free acid per litre (pH:> 1·5 to 2.5). The average flow through the plant is 1,250,000 gallons per day, which corresponds to a production of 300...

Jan 1, 1958

By Crook KAW

New sedimentological and biostratigraphic data indicate that the Leron Formation in the Markham Suture Zone, Papua New Guinea (PNG) represented Pleist- ocene alluvial fan-delta deposition in shallow marine to lacustrine environments. The distribution of sedimentary regimes in the Leron Formation indicates that during collision zone evolution, various tectono-sedimentary regimes do not always track the movement of the triple-junction systematically as idealized by Crook's (1989a) model. The migration of various tectono-sedimentary regimes are also controlled and influenced by the effects of second-order geometric features of the convergent margins. Leron Formation in the Markham Valley represents late to post-collisional marine to fluvial molasse. Foraminifera indicate that the collision and concomitant suturing of the Markham valley occurred after 1.32Ma.

Jan 1, 1991

By Pengfu Tan

Lead blast-furnace bullion cools to near its freezing point in an operation known as copper drossing or hot drossing usually contains 0.02-0.06% copper. The removal of this copper is usually carried out in a batch operation known as sulfur drossing. Sulfur is stirred into the bullion at temperatures near its freezing point, and the dross of copper and lead sulfides that floats to the surface is skimmed off manually. A thermodynamic model has been developed to simulate the copper drossing. The phase diagram of Pb-Cu-S system has been calculated, and the effects of the process parameters, such as temperature, copper content, and sulfur content, on the drossing process have been simulated and discussed.

Jan 1, 2006

By Davorin Kolic, Harald Wagner

Conventional ground support in accordance with latest state-of-the-art considers proper preparation of geotechnical investigation, structural design, observation during construction and fair risk sharing documents. Depending on the ground, there are different means and methods, reflecting different experiences. The paper is presenting ground support concepts, as mostly used in Europe during the past three decades. It discusses the use of anchors as well as the use of steel arches respectively combinations. It also discusses different applications of plain shotcrete, respectively fibre reinforced shotcrete. As excavation sequence is a major input to create the ground arch, the paper discusses also criteria to create closed ring conditions. Finally deformation criteria will be presented with case histories in order to control stability of the structure.

Jan 1, 2001

By Fang Wu

The paper designs an extraction flow for the total recovery of nickel and cobalt and removing magnesium simultaneously from the cadthodic materials of the spent hydrogen-nickel and cadmium-nickel batteries. The separation of Co, Ni and Mg though P507 extraction .The extraction equilibrium pH is 4.5~5.0, ßNi/Co is 140~180, and ß Ni/Mg is 20~25; nickel and magnesium are scrubbed in two steps, in which the equilibrium pH of nickel and magnesium scrubbing is controlled at 5.0±0.1 and 4.4±0.1 respectively. The stepwise scrubbing technique is adopted to remove 94.5% of magnesium and to recover 99.45% of nickel and 95.35% of cobalt. During the integrated extraction and precipitation process the total recovery fraction of nickel and cobalt are 99.99% and 99.95%, and the recovery fraction of magnesium is 94.02%.The recovered NiSO4 and CoSO4 solution are enriched and crystallized.

Jan 1, 2009

By Theodore J. Williams

Computer control has been one of the fastest moving and most glamorous fields of industrial development in the past decade. A review of this period shows some truly remarkable accomplishments in both system development and applications. In addition, work now under way promises results which will continue the rate of progress of the past. This paper will review the history and status of the field of computer control and point out the major breakthroughs which have occurred. It will analyze the present trends and extrapolate them to predict the early future developments in the field.

Jan 1, 1968