Flotation response of a bituminous coal sample in presence of a pyrolitic oil recycled from used car tires

In this research work, the role of a pyrolitic oil (PO) produced by pyrolysis of used car tires in coal flotation was evaluated using an extended full factorial design. Effects of operating parameters including pulp solid content and the concentration of pine oil, diesel oil, and pyrolitic oil on ash content and yield of final concentrate as process responses were assessed using experimental and statistical analyses. Fourier Transform Infrared Spectroscopy (FTIR) technique revealed that PO consists of hydrocarbons and their hydrophilic oxides. Analysis of variance (ANOVA) results indicated that the main effect of all parameters on flotation responses was significant. Experimental results showed that pyrolitic oil increased both the ash content and total yield through a nonlinear trend in ranges of 5% and 40%, respectively. Nonselective interaction between pyrolitic oil and pine oil molecules, and competitive adsorption of PO and diesel oil on the surface of coal particles were found to be the chief reasons behind the observed curved behavior of flotation measures. The negative effect of PO on ash content of final concentrate was also ascribed to the interaction between hydrophilic groups in PO structure and the oxide nature of noncombustible materials in coal particles.

Automated summary

The role of pyrolitic oil (PO) produced from used car tires in coal flotation was evaluated through experimental and statistical analyses. The addition of PY increased the ash content and total yield of the final concentrate in a non-linear trend within certain ranges. The non-selective interaction between PO and pine oil molecules, as well as the competitive adsorption between PO and diesel oil on coal particle surfaces, were identified as the main factors contributing to the curved behavior of flotation responses. The negative effect of PO on the ash content was attributed to the interaction between the hydrophilic groups in PO structure and the oxide nature of non-combustible materials in coal particles.