Abstract
The objective of this study is to selectively recover potassium magnesium phosphate (MgKPO4/MPP) of a large shape from wastewater containing phosphorus and potassium. Magnesium chloride as precipitation reagent was added to the synthetic wastewater including phosphate and potassium ion. Changing the addition rate and stirring rate induced the selective crystallization of MPP of large shape, indicating that MPP of high purity of large shape improve the performance of quality control and solid-liquid separation. The obtained white precipitate was needle-like crystals of typical potassium magnesium phosphate. Changing standing time and addition time induced ratio of MPP and Mg3(PO4)2. Changing stirring speed, length of the crystal was changed. The production of magnesium potassium phosphate was confirmed by Energy dispersive X-ray spectrometry. Setting short standing time, longer addition time, slower stirring rate and lower Mg concentration to be added, selective crystallization MPP of large shape can be recovered.
