Indirect-fired, all ceramic pyrochemical reactor

An indirect-fired furnace reactor comprising:

• a furnace housing which defines a combustion chamber, a solids feed bin and a product discharge bin;
• a reaction tube having an interior and an exterior, a distal end located adjacent to and communicating the tube interior with the solids feed bin and a proximal end adjacent to and communicating the tube interior with the product discharge bin, said distal and proximal ends being supported by the furnace housing to seal the tube exterior within said combustion chamber in a gas tight relationship,
• a screw conveyor having an exterior surface within the tube interior, wherein the screw conveyor exterior is comprised of a refractory material having a thermal conductivity of less than 25 BTU/hr.multidot..degree.F..multidot.ft.sup.2 /inch at 1832.degree. F.;
• a driving device for rotating the screw conveyor;
• a conduit which communicates the tube interior to an area external to the combustion chamber;
• means for generating coherent diffusion resistant elemental sulfur which is in communication with the conduit;
• and
• a heat source for supplying heat into the combustion chamber.

A method for producing a solid product from a solid reactant comprising:

• providing a reaction tube fabricated of a refractory material having a distal end located adjacent to and communicating a tube interior with a solids feed bin and a proximal end adjacent to and communicating the tube interior with a product discharge bin, said distal and proximal ends being supported by a furnace housing to seal an exterior surface of the tube within a combustion chamber in a gastight relationship;
• providing at least one reaction tube support between the reaction tube distal end and the reaction tube proximal end;
• passing a solid reactant into the tube interior, said solid reactant selected from the group consisting of mineral ores, metallic halides, metallic carbides, metallic carbonates, metallic oxides, metallic phosphates, metallic sulfides and metallic sulfates;
• moving the solid reactant through the tube interior by rotating a screw conveyor within the tube interior;
• and
• heating the exterior surface of the tube to a temperature required for reaction of the solid reactant to produce the solid product during the passage of the solid reactant through the tube.

A method for producing a solid product from gypsum comprising:

• passing CaSO.sub.4 into an interior area of a reaction tube having a distal end located adjacent to and communicating the tube interior with a solids feed bin and a proximal end adjacent to and communicating the tube interior with a product discharge bin, said distal and proximal ends being supported by a furnace housing to seal an exterior surface of the tube within a combustion chamber in a gastight relationship,
• moving the CaSO.sub.4 through the tube by rotating a screw conveyor within the interior of the tube;
• and
• supplying to the interior of the reaction tube coherent diffusion resistant elemental sulfur gas while heating the exterior of the tube to a temperature of at least about 1832.degree. F. during the passage of the CaSO.sub.4 through the tube.

An indirect-fired all ceramic furnace reactor comprising:

• a furnace housing which defines a combustion chamber, a solids feed bin and a product discharge bin;
• a spaced apart plurality of reaction tubes, each of said tubes having an interior and an exterior, a distal end located adjacent to and communicating said tube interior with said solids feed bin and a proximal end adjacent to and communicating said tube interior with said product discharge bin, said distal and proximal ends being supported by said furnace housing to seal said tube exterior within said combustion chamber in a gas tight relationship, wherein each of said reaction tubes is fabricated of a refractory material, wherein said refractory material has a thermal conductivity of at least about 38 BTU/hr.multidot..degree.F..multidot.ft.sup.2 /inch at 1832.degree. F.;
• at least one reaction tube support for each of said reaction tubes between said reaction tube distal end and said reaction tube proximal end;
• a screw conveyor for each of said reaction tubes having an exterior surface within said tube interior;
• a driving device for each of said reaction tubes for rotating said screw conveyor;
• and
• a heat source for supplying heat into the combustion chamber.