Solvent extraction is a commercial method for production of pure materials such as zirconium and hafnium and their compounds from multi-component scrubber solution. In the extraction of zirconium and hafnium salts from HNO3, HCl, HClO4 and H2SO4 into neutral organophosphorus compounds (NOPC) - such as tributyl phosphate (TBP)- in case using mixtures of inorganic acids, NOPC extracts zirconium and hafnium with separation factor considerably exceeding the corresponding value for extraction from solution of individual acids. A still higher separation level is obtained when using mixture of acids, especially those of nitric-hydrochloric acids. In this paper, the extraction of zirconium from solution containing nitric-hydrochloric acids using TBP in treated kerosene as diluents has been studied. The following parameters have been investigated: effect of extractant, nitric-hydrochloric acids and zirconium concentrations, mixing time, acidification of organic phase, the organic/aqueous phase ratio and temperature on the extraction of zirconium.

An experimental study has been made of the hydrodynamics of a stage mixer-settler to obtain appropriate design information. In this paper several tests were done according to full factorial design of experiments with high reliability, since each test recurs seven times and the results of  them are very close to each other(P=1 bar and T=25oC). Sauter diameter in each test is determined with photographing of both mixer and settler and holdup quantity is measured by vacuum pump at the end of each test. In each test, dispersion height and dispersion length are determined by photographing of settler. Sauter diameter has been compared with Calderbank model and finally, a model has been suggested.

Finding special periodic orbit in the highly chaotic problems is very complicated. Thus, deriving an effective algorithm for finding such orbits is important. In this paper, the spatial orbits in three-body problems are studied. Then, an algorithm is derived in order to help to find these orbits. This algorithm includes scanning the space, refining better points, and finally, minimizing the position error of the orbit by means of numerical methods.

Photocatalytic method was used as an efficient and simple way for degradation of trin-butyl phosphate (TBP). In contrast to other methods, in this method the mineralization occurs and no twin pollution is generated. Nd doped TiO2 was synthesized via sol gel process and characterized by XRD and TEM tecniuqes. Then it was used as photocatalyst for TBP degradetion. It was found that the solution pH has important effect on degradation efficiency and kinetic. Degradation was more efficient in both acidic and alkali media. The kinetic studies indicated that the second order model at neutral pHs range was the dominant while in acidic or alkali conditions the kinetic models were first and third order respectively. By proceeding the degradation process, some products and byproducts are generated, which lead to the change of the solution pH and change of degradetion mechanism and kinetic. The LC MS was used to detect the intermediate and final products. Results showed that the method has high efficiency and is a promising procedure for decomposition of TBP.