Browsing by Author "Salminen, Anssi"

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  • Mittausmenetelmät turbulenssisuureiden määrittämiseksi
    (2008) Salminen, Anssi
     Kemian ja materiaalitieteiden tiedekunta | Bachelor's thesis
  • Hydrometallurgiset erotusmenetelmät
    (2010) Salminen, Anssi
     School of Chemical Engineering | Master's thesis
    Hydrometallurgy is a technique used in the mining industry for separation of metals from ores. Hydrometallurgy is based on the use of hydrochemistry. Usually hydrometallurgy is divided into two areas: the leaching of the ore and the separation of the dissolved materials from the aqueous solution. The removed materials can be either impurities or the actual metal being recovered. The same separation methods are being used in both cases. Most common methods used in hydrometallurgical separation are crystallization, precipitation, ion exchange and liquid-liquid extraction. In addition, cementation and electro winning are being used as well. Purpose of this work was to introduce the basic theory and modelling of these separation methods. Empirical simulation models for crystallization and ion exchange processes were created also. The simulation models used empirical equations in order to minimize the computing times. Both models were designed to simulate a continuous process based on experimental data. They estimate the necessary volume and number of units for a specific input flow rate and concentration. Cost functions were also included in the models to estimate the capital costs of the equipment. Crystallizer model was based on the ideal MSMPR-assumption and the ion exchangers were assumed to have fixed beds. The effluent concentration of an ion exchanger was presumed to follow the Bohart-Adams solution. In the lack of reference values the accuracy of the models could not be estimated but test simulations with fictitious test values show that the models are quite suitable for fitting the experimental data.