Preparation of nano-sized magnetic particles from spent pickling liquors by ultrasonic-assisted chemical co-precipitation.

Abstract The aim of this study is to develop a new method for the preparation of high-value, environmentally friendly products from spent pickling liquors. An ultrasound treatment was introduced into a chemical co-precipitation process to control the size of the particles produced. The particles were characterized by X-ray powder diffraction and transmission electron microscopy. The magnetic parameter was measured with a magnetic property measurement system. The product consisted of ferrous ferrite (Fe 3 O 4 ) nano-sized cubic particles with a high level of crystallinity that exhibited super-paramagnetism.