Chemical treatment of simulated solution of evaporator concentrate for immobilization in bitumen

Studies on the preparation of leach-resistant insoluble boron compound from simulated solution of evaporator concentrate are reported in this work. The insoluble compound CaB6O10. 4H(2)O has been prepared from simulated solution of evaporator concentrate by chemical treatment with calcium chloride solution. Other insoluble compounds CaB3O4 . 6H(2)O/Ca3B4O9 . 9H(2)O/Ca[B(OH)4](2) . 2H(2)O and NaCaB5O6 . 8H(2)O/NaCaB5O6 .(OH)(6) . 5H(2)O/Ca2B6O11. 13H(2)O have been prepared from simulated solution of evaporator concentrate with calcium hydroxide under controlled conditions of temperature and time. Identification and characterization of these compounds have been done by X-ray diffraction, optical microscopy and differential thermal and thermogravimetric analysis. For low-level radioactive waste treatment, immobilization of insoluble berate compounds in bitumen will produce leach-resistant suitable waste product for safe disposal. Copyright (C) 1996 Elsevier Science Ltd.