Bleaching of red clay using Na2S2O4 and NaBH4 in acidic solutionBui Thi Hoa, Le Hong Phuc, Nguyen Quan Hien, Nguyen Thi Nhat Quynh, Dao Hiep Thanh, Tran Tan Nhat and Bui Xuan VuongE3S Web Conf., 496 (2024) 01003DOI: https://doi.org/10.1051/e3sconf/202449601003