Patent ID: 6268590
Filing Date: 2001-07-31
Classification: C22B,F27B,Y02P

Abstract:
A mercury retorting apparatus for continuous removal of mercury from dry, semi-granular, and sludge materials contaminated with mercury as part of a mercury recovery system, the mercury retorting apparatus being for mounting to a base, comprising:a container means operatively connectable to the mercury recovery system such that a vacuum can be pulled therein comprising an elongate retorting tube having first and second end portions, said retorting tube being powered to rotate;a powered input means for continuously introducing the material into said retorting tube without substantially reducing the vacuum within said retorting tube, comprising a powered screw feed assembly having an elongate feed tube and a closely fitting elongate feed screw which is retained longitudinally within said feed tube and which is powered to rotate therein, said retorting tube being of a larger diameter than said feed tube such that said feed tube extends into said first end portion of said retorting tube, and wherein the material seals against vacuum loss in said retorting tube by being compacted so as to form a seal within said powered screw feed assembly during operation thereof;an output means for removing the material from said retorting tube without substantially reducing the vacuum within said retorting tube;first and second seals which are attached to and seal respectively between said powered screw feed and said first end portion of said retorting tube, and between said second end portion of said retorting tube and said output means,said first end portion of said retorting tube being necked-down relative to the remainder of said retorting tube to a diameter closer to that of said feed screw tube so as so allow said first seal to be more compact;a heating means for heating the material within said container means so as to volatilize the mercury contained therein to form an offgas which includes air, mercury vapor, dust particles, and water vapor, said heating means being positioned so as to heat a mid-portion of said retorting tube between said first end portion and a second end portion thereof; andoffgas removal means for removing the offgas from said container means.