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Protocol For Evaluating Flotation Aids With A Laboratory-Scale Flotation Column

Protocole d’valuation des dispositifs de flottation l’aide d’une colonne de flottation de laboratoire

Protocole d’valuation des dispositifs de flottation l’aide d’une colonne de flottation de laboratoire

Abstract: In order to identify the best surfactants for certain types of recovered paper blends, we have developed a useful tool for recyclers wanting to evaluate and compare flotation aids. With the addition of new features such as on-line air content measurement in a flotation column, this novel method measures the flotation rate constant and characterizes the performance of a flotation col- lector. The method uses a small pilot flotation column that can be operated in either a continuous or batch mode. The column is set up for accurate measurement and control of air content, froth height, and air and liquid flows. On-line estimation of mean bubble diameter is also possible. Combining the information obtained from on-line and laboratory measurements will enable the evaluation of the flotation rate constant and two basic parameters governing pulp aeration and ink collection. It is only when both parameters are well controlled that precise and conclusive results are obtained. In this report, we provide examples of tests carried out using conventional fatty acid soaps for flotation of an ONP/ OMG pulp. During the development of the method, the contact time and temperature during the addition of anionic soaps were found to be critical.

Paper presented at the 95th PAPTAC Annual Meeting 2009 in Montreal, Que., February 3-4, 2009.

Keywords: FLOTATION, BRIGHTNESS, IMPURITIES, REMOVAL, DEINKING, EVALUATION, FINES, SURFACTANTS, WASTE PAPERS

Full manuscript available at www.paptac.ca.