THE DISPERSION-FLOCCULATION BEHAVIOUR OF THE NATURAL RAW CLAY SAMPLES FROM OMARSKA MINE

Abstract

In present paper, studied were the dispersion-flocculation behaviour of the primary natural raw „clay samples” from Omarska mine (Republic of Srpska, Bosnia and Herzegovina). Namely, our previous results showed that during the processing of iron
ore in the Omarska mine, large quantities of fine sized (<15μm) waste sludge, with relatively high Fe concentrations, were generated. Sludge samples are composed of major goethite and quartz, less clay minerals, and minor magnetite and todorokite. Selective flocculation is one of the methods that can be applied for the separation of fine class iron minerals from impurities and depends on the individual components of the sludge and their behaviour. This paper presents part of the research of the individual components of the sludge. The „clay samples” are composed of major quartz and clay minerals, which dominate over minor contents of feldspars, amphiboles, goethite and hematite. The clay minerals were identified as mostly illite-sericite which prevails over kaolinite, and with chlorites which appears only sporadically. The dispersion-flocculation behaviour was studied by settling and flocculation experiments and Zeta potential measurements. A three different dispersants (sodium hexametaphosphate, sodium-pyrophosphate and sodiumsilicate), and anionic and non-ionic polyacrylamide (PAM) flocculants were used. It was established that the best results were achieved with sodium-hexametaphosphate (1000 g/t) and anionic A100 PAM.
Keywords: Omarska mine, sludge, clays, dispersion-flocculation behavior.