Synthesis of large scorodite particles using short period time sonication to enhance agglomeration of precursor

The effect of various sonication frequencies (28 kHz, 200 kHz, and 1.7 MHz) on the size of synthesized scorodite particles was investigated. First, the growth of the precursor with oxidation was observed in a synthesis process using stirring. The precursor size changed with the elapsed time and was 3 µm at 20 min. The scorodite particles were then synthesized following different procedures such that a different size of the precursor was irradiated by each ultrasound frequency for 10 min during the oxidation process with stirring for a total duration of 180 min. For each frequency, the size of the synthesized particles varied depending on the size of the precursor. Large scorodite particles can be synthesized (70 °C) by irradiating for only 30 min at various frequencies after the size of the precursor particles reaches the optimal range.