Abstract: A method for purifying metal M1 particles manufactured by an electrochemical reduction process, the method comprising the steps of introducing the metal M1 particles into a heat source (13) at a temperature substantially equal to or higher than the melting point of M1 so as to cause vaporisation of some or substantially all of the contaminating impurities present, removing the vaporised impurities from the vicinity of the particles, and cooling the purified metal M1 particles. The purified particles can be used directly in lower temperature powder metallurgy processes and have a fully dense spherical particle morphology, imparting good flowability. The purification process can also be incorporated as an integral stage of sheet or stock production processes based on particle feedstocks that have been produced by electrochemical reduction.

Abstract: Apparatus and method for freezing large pipe plugs, including in particular subsea applications, wherein the apparatus includes a jacket adapted to encircle a section of large pipe, a recycling refrigeration unit having said jacket connected as an evaporation chamber and, for subsea applications, a submersible housing enclosing a portion of such refrigeration unit; the method including landing a submersible recycling refrigeration unit on or proximate a pipe and cycling, and preferably reverse cycling, a refrigerant therethrough.