Authors:Shao-Ning Yu, Zheng-Ping Fan, Li Ma, Yan-Zhao Yang, and Bo-Rong Bao
The influence of the concentration of nitric, hydrochloric and phosphoric acids, petroleum sulfoxides (PSO), salting-out agent,
kind of diluent and temperature on the distribution ratio of U(VI) and Th(IV) has been systematically studied. It is found
that the extraction regularity of PSO is similar to that of TBP. The distribution ratio in phosphoric acid is lower, but it
increases with the increase of hydrochloric acid concentration and reaches a high value. The U(VI) exhibits the maximum distribution
ratio at 3–4 mol/l HNO3. The distribution ratio of U(VI) and Th(IV) increases rapidly in the presence of a salting out agent. The extracted compounds
are determined to be UO2(NO3)22PSO and Th(NO3)42PSO. The extraction enthalpies of U(VI) and Th(IV) with PSO were also calculated.
Sorption of U(VI) from aqueous solution to decarbonated calcareous soil (DCS) was studied under ambient conditions using batch
technique. Soil samples were characterized by XRD, FT-IR and SEM in detail and the effects of pH, solid-to-liquid ratio (m/V), temperature, contact time, fulvic acid (FA), CO2 and carbonates on U(VI) sorption to calcareous soil were also studied in detail using batch technique. The results from experimental
techniques showed that sorption of U(VI) on DCS was significantly influenced by pH values of the aqueous phase, indicating
a formation of inner-sphere complexes at solid–liquid interface, and increased with increasing temperature, suggesting the
sorption process was endothermic and spontaneous. Compared to Freundlich model, sorption of U(VI) to DCS was simulated better
with Langmuir model. The sorption equilibrium could be quickly achieved within 5 h, and sorption results fitted pseudo-second-order
model well. The presence of FA in sorption system enhanced U(VI) sorption at low pH and reduced U(VI) sorption at high pH
values. In absence of FA, the sorption of U(VI) onto DCS was an irreversible process, while the presence of FA reinforced
the U(VI) desorption process reversible. The presence of CO2 decreased U(VI) sorption largely at pH >8, which might due to a weakly adsorbable formation of Ca2UO2(CO3)3 complex in aqueous phase.
Authors:Lin-Quan Liao, Hong-Jian Wei, Ji-Zhen Li, Xue-Zhong Fan, Ya Zheng, Yue-Ping Ji, Xiao-Long Fu, Ya-Jun Zhang, and Fang-Li Liu
The compatibility of poly(3-nitromethyl-3-methyloxetane) (PNIMMO) with some energetic materials are studied by using pressure DSC method in detail. Cyclotetramethylenetetranitroamine (HMX), cyclotrimethylenetrinitramine (RDX), nitrocellulose (NC), nitroglycerine (NG), N-nitrodihydroxyethylaminedinitrate (DINA), and aluminum powder (Al) are used as common energetic materials, and 3,4-dinitrofurzanfuroxan (DNTF), 1,3,3-trinitroazetidine (TNAZ), hexanitrohexazaisowurtzitane (CL-20), 4,6-dinitro-5,7-diaminobenzenfuroxan (CL-14), 1,1-diamino-2,2-dinitroethylene (DADNE), and 4-amino-5-nitro-1,2,3-triazole (ANTZ) are used as new energetic materials. The results show that the binary systems of PNIMMO with HMX, RDX, NC, NG, DINA, Al, CL-14 and DADNE are compatible, with TNAZ, CL-20 and ANTZ are slightly sensitive, and with DNTF is sensitive.