1. Development of a new cleaner production process for producing chromic oxide from chromite ore
2. Green manufacturing process of chromium compounds
3. Li, Z.; Zhang, Y.; Zheng, S.; Qi, T.; Li, H.; Xu, H.; Wang, Z.Method for Production of Alkali Metal Chromates. USA Patent: 7968066 B2, Sept 30, 2004.
4. Zheng, S.; Zhang, Y.; Xu, H.; Xiao, Q.; Zhang, Y.One kind of liquid-phase oxidation of chromite production of sodium chromate cleaner production methods. CHN Patent: CN102 001708 A, April 6, 2011; in Chinese.