KBF₄ conversion unit at HWP-Talcher is for conversion of Boron Tri-fluoride Di-Ethyl Ether complex [BF₃.O(C₂H₅)₂], which contains enriched 10B of 65% isotopic purity, to Potassium tetra-fluoro borate (KBF₄). The basic process involves chemical reaction between BF₃.O(C₂H₅)₂and KF to KBF₄ followed by filtration, drying of slurry & grinding to make KBF₄ powder

The process involves mainly four steps as given below:

• Preparation of KF solution:

  Reaction: KF (s) + H₂O (l) ----à KF (aq.) + DH

  KF solution is prepared taking aqueous mother liquor, collected from the previous batch containing water, KBF₄, BF₃ and KF and required amount of DM water in the reaction vessel by which the homogeneous solution of KF prepared.

• Conversion of BF₃ complex into KBF₄:

  Reaction: BF₃.O(C₂H₅)₂ + KF (aq.) -------à KBF₄ + O(C₂H₅)₂ + H₂O

  Required amount of BF₃-ditheyl ether complex is taken to the reactor vessel and the previously prepared KF solution from reaction vessel is added slowly to BF₃-ether complex by using dosing pumps into the reactor. The mixture of KF solution and BF₃ ether complex is agitated continuously in the reactor. The KF in the solution reacts with BF₃ to form Potassium Tetra Flouro Borate (KBF₄).

  Since the conversion reaction is exothermic in nature, the heat of reaction will be removed by circulation of chilled water/brine through jacket of the Reactor. After complete addition of KF solution to BF₃ complex, the reactor charge will be kept under digestion.

• Filtration of KBF₄

  After completion of reaction, the slurry contains KBF₄, ether is subjected to filtration by both pressure and vacuum drying options. The filtrate from filter is collected and re-circulated for further filtration. Thus vacuum dried cake is further dried in vacuum oven dryer for ensuring complete removal of moisture.

• Separation of Diethyl ether & aqueous phase.

  After complete filtration, the filtrate is subjected to gravity separation of organic and aqueous phases. After keeping about an ½ hr for settling, the aqueous phase settled at bottom will be recycled back to KF dissolver for its reuse.