公开(公告)号：US06616906B2

公开(公告)日：2003-09-09

申请号：US10105573

申请日：2002-03-25

申请人： Dennis L. Myers ,  Robert W. Hudson ,  Nathan P. Mills ,  David Michael Razmus ,  Vincent Payen

发明人： Dennis L. Myers ,  Robert W. Hudson ,  Nathan P. Mills ,  David Michael Razmus ,  Vincent Payen

IPC分类号： C01B2524

CPC分类号： C01B25/24

摘要： An improved method for making polyphosphoric acid from phosphoric acid includes the steps of introducing a first phosphoric acid feed stream into the top end of a packed column, introducing a second phosphoric acid feed stream into a stream of hot air to form a stream of hot air and acid, introducing the stream of hot air and acid into the bottom end of the column, and polymerizing phosphoric acid of the first and second phosphoric acid feed streams to make polyphosphoric acid. By-product phosphoric acids containing organic contaminants may be substituted for all or part of the phosphoric acid stream being introduced into the bottom end of the column to allow recovery of the phosphorus values of the by-product phosphoric acids.