Nowadays, there are strong economical, ecological, and social incentives to develop novel green chemicals from renewable resources to reduce the environmental impact of processing. Cellulose, which is the most abundant natural polymeric source, offers one promising green alternative that could replace the present synthetic chemicals. In this study, two types of modified nanocelluloses (amphiphilic and hydrophilic) were produced and tested to understand their ability to function as collectors and depressants in the mineral flotation process for pure hematite and pure quartz. Hydrophilic nanocellulose (called dicarboxylic acid nanocellulose (DCC)) was observed to be a more selective depressant for hematite than for quartz. DCC seems to be most effective at a pH level of 6. Amphiphilic nanocrystalline celluloses (ANCCs) work as collectors. ANCCs were pH-dependent collectors, and they worked well at a pH value of 10 in the case of the investigated oxides (hematite and quartz). This research indicated that nanocelluloses functioned already at least at the same level as a commercial starch depressant for hematite and as an ether amine collector for quartz.

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A study was made of the classification of pulp, paper, and peat particles by size with a device called a tube flow fractionator. An accurate and simple experimental model was formulated in order to estimate the time required for fractionation, yielding an excellent correlation between the observed and predicted fractionation times. The results showed that the fractionation time of a certain size of pulp, paper, and peat particles in the tube flow device can be accurately estimated from the length, width, and thickness of the particle. The results can be used to facilitate the selection of specific fractions of pulp and paper samples.

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