Ziel der vorliegenden Arbeit ist es, mit Hilfe einer neu entwickelten Methode zur getrennten Bestimmung des Feststoffausbringens durch Trübemitführung und Heterokoagulation die Wirkung einiger wichtiger Prozessparameter zu bewerten. Darüber hinaus ist der Einfluss der Modifizierung des Suspensionszustandes (Änderung der Turbulenzintensität) bzw. des Flockungszustandes hydrophiler Teilchen auf die Trübemitführung feiner hydrophiler Teilchen in mechanischen Flotationsapparaten aufzuklären. Die Ergebnisse der vorliegenden Arbeit sind ein Beitrag zur Erweiterung der Kenntnisse über die Mechanismen der Trübemitführung in mechanischen Flotationsapparaten. Sie liefern wesentliche neue Hinweise zur Steuerung und Reduzierung der Trübemitführung. Aus den Schlussfolgerungen der Arbeit können wichtige Maßnahmen und Kriterien zur Optimierung der Feinstteilchenflotation bei der Aufbereitung komplex zusammensetzter, wertstoffarmer Rohstoffe und für das Recycling von festen Abfällen abgeleitet werden.

Thesis (M.S.)--University of Missouri, School of Mines and Metallurgy, 1930. / The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed February 10, 2010) Includes bibliographical references (p. 63-64).

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The effluent quality from mining & processing operations is monitored to ensure that maximum allowable limits are not exceeded. Recently, copper concentration levels in the effluent discharge flows of a copper and nickel mining company in Ontario have indicated increasing trends. A chemical particular to the problem is use of diethylenetriamine (DETA) in the process. Adsorption tests were conducted to investigate the ability of various adsorbents to remove and retain copper complexed with DETA and triethylenetetramine (TETA) in solutions. The tests were divided into two sections: gangue adsorbents (silica and pyrrhotite) and high capacity adsorbents (natural bentonite, peat, zeolite Y and zeolite ZSM-5). Pyrrhotite as a sulphide gangue had a greater adsorption capacity than silica for the concentration range studied. At 1 ppm initial concentration, over 80% of copper chelate was removed by minus 400 mesh pyrrhotite compared to 72% of the same size silica. Freundlich and Langmuir isotherm models of adsorption are applicable. However, the Langmuir adsorption isotherm was found to more closely represent the experimental data with a maximum adsorption capacity of 129.9 μg/g for copper complexed with DETA on pyrrhotite. For the high capacity adsorbents, natural bentonite, zeolite Y and peat each worked well at removing the copper chelates. Zeolite Y had the highest capacity for copper chelates and a maximum adsorption capacity of 55.9 mg/g. Freundlich and Langmuir adsorption isotherm models were studied with the Langmuir isotherm model more closely representing the experimental data. iii Studies were also conducted on the effect of temperature. This led to a thermodynamic analysis of adsorption and estimation of activation energies. The standard free energies estimated for adsorption of copper chelated on adsorbents studied were nearly always negative, typically varying from around -2 kJ/mol to -7 kJ/mol with increasing temperature. The activation energy was found to be highest for the natural bentonite system suggesting a strong adsorption (e.g. 40.5 kJ/mol for CuTETA). Desorption experiments on the peat indicated very poor reversal for the process, confirming that the adsorption of copper chelates on high capacity adsorption was indeed very strong. Settling experiments indicated copper chelates were highly effective as coagulants on bentonite. / Thesis (Master, Mining Engineering) -- Queen's University, 2013-12-25 15:00:39.553

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Froth flotation is the most efficient method for phosphate separation, which is a physic-chemical separation process based on the difference of surface properties between the valuable minerals and unwanted gangue minerals. However, the presence of clay slimes in the slurry after grinding consumes a large amount of reagents, decreases the collision probability between bubbles and minerals, prevents phosphate particle attachment to air bubbles, and thus considerably reduces flotation recovery and concentrate grade. Georgia Pacific Chemical, LLC has recently developed novel depressants, i.e., clay binders, which are a series of low molecular weight specialty polymers to help improve phosphate flotation performance by selectively agglomerating and depressing clay particles, thus lowering their surface area and reducing the adsorption of surfactants. This thesis addresses the effects of clay binders on phosphate flotation performance and their adsorption behavior on different minerals in a sedimentary phosphate ore. Quartz Crystal Microbalance with Dissipation technique (QCM-D) was used to study adsorption characteristics of clay binders and batch flotation tests were performed under different conditions to investigate phosphate flotation performance. The experimental results have shown that clay binders significantly improved phosphate flotation selectivity and reduced the dosages of collector and sodium silicate used as dispersant in the industry.