Ultrasonic treatment and its applicability for the selective treatment of borax clayey waste sludge

Sludge treatment is one of the most difficult challenges for many industrial plants. In recent years, the use of ultrasound power has received considerable attention as one of the increasing tool for managing of this problem. Power ultrasound enhances chemical and physical changes in a liquid medium through the generation and subsequent destruction of cavitations bubbles. Therefore, the increased friction and stress in solution resultant with cleaning of the solid surfaces and dispersion of bonded/aggregated solid particles. In this study, the basic fundamentals of ultrasonic treatment and process variables were briefly overviewed. The study was also extended with preliminary analyses performed to determine its ability on the extraction of major and trace elements from Kırka Borax Concentrator tailings mainly boron as boric acid and Li as Li reach pregnant solution (PLS). Prior and after the sonification tests, physical, chemical and morphological analyses were carried out to determine the treatment performance. It was found that sonication leads the liberation of boron minerals from sludge and with the help of temperature they are dissolved and re-crystallized on clay substrate during cooling stage. The extraction test performed with these crystals revealed that Li-rich solution (that can be further use as source of lithium carbonate or lithium hydroxide production), and boric acid could be produced with easy and low cost beneficiation method.