The effect of mutual interaction (heteroaggregation and dissolution interference) between different fine mineral particles in their multi-component suspensions complicate the possibility of selective separation. Presenting results obtained on three two-component mixtures (silica-silica/aminopropyl, hematite-quartz, and magnesite-quartz) it has been shown that this effect can be evaluated with the ELS technique by comparing zeta potential distributions determined prior to and after mixing the individual components. A theoretical interpretation of evaluated heteroaggregation was introduced.