Valorization of Phosphate Gypsum and Electrolytic Manganese Residue

The PG was collected from a phosphate gypsum residue site in Jingmen, Hubei Province, China. The EMR was derived from an electrolytic manganese factory in Guangxi province in China. The chemical compositions of PG and EMR measured by X-ray fluorescence (XRF) are shown in Table 1. The content of calcium sulfate dihydrate in EMR and PG is 51.60% and 83.38%, respectively, as determined by the testing method outlined in Fig. S1 and the standard GB/T 23456-2018. Analytical pure anhydrous ethanol and glycerol were purchased from Sinopharm Chemical Reagent (Beijing, China). Distilled water was used in all processes.Table 1

Chemical compositions of PG and EMR (wt%).

Chemical compositions	SO3	CaO	SiO2	Al2O3	P2O5	Fe2O3	MgO	MnO	Others
PG	40.099	28.45	9.166	1.568	1.206	0.685	0.222		18.604
EMR	26.733	10.664	18.544	1.985	0.172	5.877	2.882	5.203	27.94