Tributyl phosphate with selective

At Bolton, we also have attempted to introduce volatile and possible vapor phase-active, phosphorus-based FR components in back-coating formulations.60 62 The selected FRs included tributyl phosphate (TBP), a monomeric cyclic phosphate Antiblaze CU (Rhodia Specialties) and the oligomeric phosphate-phosphonate Fyrol 51 (Akzo). When combined with an intumescent char-forming pentaerythritol (PER) derivative (NH1197, Chemtura) and applied as a back-coating on to cotton and polypropylene substrates, significant improvements in overall flame retardancy were observed. 

The use of extractants of the same general type as tributyl phosphate, i.e., neutral extractants containing the P=0 coordinating group, but designed with specially selected extraction properties should have many advantages in the development of LLE systems which may be applicable to reactor fuel reprocessing. 

The selective extraction of plutonium from uranium or fission products depends on proper adjustment of the valence state of plutonium relative to the other ions from which it is to be separated. For instance, in decontaminating plutonium by extraction with TBP, plutonium must be oxidized to the tetravalent state, without bringing cerium into the tetravalent, ceric state. Again, to separate plutonium from uranium and the fission products in the tributyl phosphate extraction process, plutonium must be trivalent and uranium hexavalent. 

The following procedure is used for producing thorium hrom monazite sand. The sand is digested with hot concentrated alkali which converts the oxide to hydroxide. The filtered hydroxide is dissolved in hydrochloric acid and the pH adjusted between 5 and 6, which precipitates the thorium hydroxide but not the main fraction of lanthanide elements. The thorium hydroxide is dissolved in nitric acid and selectively extracted with methyl isobutyl ketone or tributyl phosphate in kerosene. This gives a rather pure organic solution of Th(N03)4. thorium is stripped from the organic phase by washing with alkali solution. 

The tributyl phosphate purification process- 73, 74 developed by the U.K. Atomic Energy Authority can accept feed solutions containing thorium which have been produced in a number of ways. - Monazite may be broken with sulphuric acid, the thorium selectively precipitated as oxalate from the major part of the rare earth constituents and dissolved in... 

---