Ullmanns, Encyklopa die der technischen Chemie, Band 24, p. 466, no date. |
Uranium Mining and Metallurgy, vol. 10, No. 3, Aug. 1991, pp. 39-47. |
Patents Abstracts of Japan, C-37, Dec. 26, 1980, vol. 4, No. 190 Recovering Molybdenum from Water Containing the Same. |
6001 Chemical Abstracts, 110:60551e (1989), Feb. 20, No. 8, Columbus, Ohio "Preparation of ammonium paratungstate with high-purity using two-step ion exchange method", no month. |
Derwent Chemical Patent Index, *MEEN, M25, 94-133033/16, SU1792993-A1, "Extn. of tungsten from carbonate solns. with improved efficiency", Mosc. Mendeleev Chem Techn Inst Feb. 15, 1991. |
Derwent Chemical Patent Index, *MEEN, M25, 94-133034/16, SU1792994-A1, "Extn. of tungsten from carbonate solns. includes extn. with salt of quat. ammonium base in organic dilutent to improve process efficiency", Mosc. Mendeleev Chem Techn Inst Mar. 15, 1991. |
Derwent, 87-133959�19!, "Extn. of rare metals from solns.--using exchange resin regenerate anionite washing solution adjust total ammonia level sodium", Khabirov, V, SU1032810A. |
Zhu, Yujun, "Extraction of ammonium paratungstate by ion exchange", Beijing Res. Inst. Chem. Eng. Metall., CNNC, Beijing, Pweop. Rep. China, Youkuangye (1991), 10(3), 39-47, no month. |