Texture and bubble size measurements for modelling concentrate grade in flotation froth systems

Includes bibliographical references (p. 237-244).Numerous, machine vision systems for froth flotation have been developed over the last ten years; however, there are many aspects of the systems, that still require further development before they become one of the standard instruments present on industrial flotation operations. This thesis aims to address these problems by developing improved measurement techniques and showing how these measurements can be used to model the concentrate grad e of the flotation cell being monitored in a manner which is, directly usable by plant personnel. This thesis, presents an improvement to the watershed algorithm for the measurement of bubble sixe distribution in flotation froths. Unlike the standard watershed algorithm, it is able to measure accurate bubble size distributions when both large and tiny bubbles are present in a flotation froth image. Flotation froths with “dynamic bubble size distribution s” are introduced and methods of reducing the high dimensional bubble size distribution data associated with them are discussed. A method of using characteristic histograms of frequently occurring bubble size distributions is introduced and shown to be an appropriate method to use. A number of standard texture measures are best suited to the classification of flotation froth images. Results show that the Fourier ring and texture spectrum based features, perform well whilst having a relatively small computational cost for classifying new images. Video footage from selected industrial operations has been used for the development of improved algorithms for the measurement of froth surface descriptors. Analyses of the relationship, between froth velocity, bubble size, froth class and concentrate grade are made. The results show that it possible to use a unified approach to model the concentrate grade, irrespective of the site on which the measurements are made. Results from three industrial case studies show that bubble size and texture measures can be used to identify froth classes. Furthermore the combination of froth classes and froth velocity information is shown to consistently account for the most variation in the data when the concentrate grade is modelled using a linear combination of these two measurements

Advanced Techniques and Efficiency Assessment of Mechanical Processing

Mechanical processing is just one step in the value chain of metal production, but to some exten,t it determines an effectiveness of separation through suitable preparation of the raw material for beneficiation processes through production of required particle sze composition and useful mineral liberation. The issue is mostly related to techniques of comminution and size classification, but it also concerns methods of gravity separation, as well as modeling and optimization. Technological and economic assessment supplements the issue

Bubble size distribution measurement, modeling and control in a laboratory flotation column

Ce travail de recherche vise à mesurer et à contrôler la distribution du diamètre des bulles (DDB) dans une colonne de flottation. L'objectif se décompose en trois parties. La première phase vise à estimer correctement la taille des bulles grâce à des algorithmes de traitement d'images prises par une caméra. La DDB obtenue est ensuite modélisée par une distribution log-normale qui est définie par deux paramètres, la moyenne et l'écart type. Deuxièmement, grâce au nouveau système de mesure et à la représentation log-normale, un modèle dynamique à gains non linéaires (structure de Wiener) dont les sorties sont la moyenne et l'écart-type de la DDB est estimé. Une bonne concordance entre la réponse du système expérimental et celle du modèle identié est observée. Finalement, une stratégie de commande prédictive contrainte basée sur le modèle de Wiener est conçue afin de réguler la BSD. Les résultats de laboratoire obtenus sont très satisfaisants

Proceedings of the Scientific-Practical Conference "Research and Development - 2016"

talent management; sensor arrays; automatic speech recognition; dry separation technology; oil production; oil waste; laser technolog

Proceedings of the Scientific-Practical Conference "Research and Development - 2016"

talent management; sensor arrays; automatic speech recognition; dry separation technology; oil production; oil waste; laser technolog

Handbook of Mathematical Geosciences

This Open Access handbook published at the IAMG's 50th anniversary, presents a compilation of invited path-breaking research contributions by award-winning geoscientists who have been instrumental in shaping the IAMG. It contains 45 chapters that are categorized broadly into five parts (i) theory, (ii) general applications, (iii) exploration and resource estimation, (iv) reviews, and (v) reminiscences covering related topics like mathematical geosciences, mathematical morphology, geostatistics, fractals and multifractals, spatial statistics, multipoint geostatistics, compositional data analysis, informatics, geocomputation, numerical methods, and chaos theory in the geosciences

Semi-strong form efficiency of lowly capitalized firms : the case of the alternative investment market, (aim) UK : an investigation of event study based abnormal returns using the single index market model

A thesis submitted to, University of Luton, Luton Business School, in fulfilment ofthe requirements for the degree ofDoctor ofPhilosophy, FinanceThis thesis examines the impact of company announcements on the daily stock returns of lowly capitalised companies. A total of 105 companies comprise the sample and 1464 events are examined over the period 21110/97 to 03/0412000. The methodology employed is primarily, empirical in nature. Event studies are conducted to gauge the impact of company announcements on stock returns using the single index market model (SIMM) as the chosen equilibrium market model for modelling abnormal returns. The study professes three mam contributions to knowledge. The empirical evidence suggests that financial announcement have a more timely impact on stock returns than non-financial announcements. Secondly, there appears to be significant over-reaction and mean-reversion exhibited by lowly capitalised firms. Thirdly, the speed of adjustment of stock prices to new information is increased in cases where shareholder concentration is high while over-reactions appear inversely proportionate to shareholder concentration. This may be a consequence of smaller firms experiencing leakage of boardroom level information prior to public announcement days

The Finance-Growth Nexus in Britain, 1850-1913

This thesis argues that the financial sector played a positive, but limited role in British economic growth from 1850 to 1913. It examines empirically the role played by different types of financial institutions: commercial banks, stock markets and merchant banks. To this end, the thesis uses recently developed time series and dynamic panel methods for the econometric analysis, alongside new data on different parts of the financial system. The results suggest that at a national level, the growth of commercial banks had a limited impact on British economic development over the long run, and stock markets had no impact. However, changes in bank lending influenced economic growth to a significant extent in the short term. Growing conservatism in bank lending practices did not significantly increase credit constraints, as had been previously suspected. Findings from new geographically disaggregated data indicate that the spread of bank offices improved the economic performance of English and Welsh counties. Increased concentration of the banking industry did not hinder economic growth, a result that challenges widespread suggestions in the relevant literature. Moreover, the development of provincial stock exchanges – exchanges outside London - did not influence county-level economic growth, contrary to the view that they were important for the expansion of local industry. Finally, this thesis is the first to assess econometrically the role of merchant banks. It demonstrates that their trade financing activities were beneficial not only for the growth of British international trade, but also for that of the domestic economy.Osk. Huttunen Foundation (2016-2018) Emil Aaltonen Foundation (2015-2016) Ellen McArthur Fun

Exploring Animal Behavior Through Sound: Volume 1

This open-access book empowers its readers to explore the acoustic world of animals. By listening to the sounds of nature, we can study animal behavior, distribution, and demographics; their habitat characteristics and needs; and the effects of noise. Sound recording is an efficient and affordable tool, independent of daylight and weather; and recorders may be left in place for many months at a time, continuously collecting data on animals and their environment. This book builds the skills and knowledge necessary to collect and interpret acoustic data from terrestrial and marine environments. Beginning with a history of sound recording, the chapters provide an overview of off-the-shelf recording equipment and analysis tools (including automated signal detectors and statistical methods); audiometric methods; acoustic terminology, quantities, and units; sound propagation in air and under water; soundscapes of terrestrial and marine habitats; animal acoustic and vibrational communication; echolocation; and the effects of noise. This book will be useful to students and researchers of animal ecology who wish to add acoustics to their toolbox, as well as to environmental managers in industry and government