Preparation of iron oxide sorbent for sulfur oxides

DETAILED DESCRIPTION The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 1.
A process for the preparation of an improved iron oxide sorbent active for use in the purification of sulfur and oxygen-containing gases comprising: a.
providing a quantity of iron sulfate-bearing solids, b.
advancing said solids to a decomposition zone, c.
contacting the solids with hot reducing gas at a temperature of from about 300.
degree.
to about 700.
degree.
C.
under conditions to produce both a solid that contains magnetite and a product gas that contains both sulfur dioxide and reducing agents, d.
separating the above magnetite-bearing solids from the gas, and e.
oxidizing said magnetite-bearing solids at a temperature below about 450.
degree.
C.
to form an iron oxide-bearing solid sorbent.
2.
The process of claim 1 wherein the magnetite-bearing solids are oxidized by contacting with a sulfur and oxygen-bearing gas in an absorption zone.
3.
The process of claim 1 wherein the concentration of reducing agent in the hot reducing gas in the reaction zone is in equilibrium composition with magnetite in the decomposition product.
4.
The process of claim 1 wherein the iron sulfate-bearing solid is principally iron sulfate.
5.
A process for preparing iron oxide-bearing sorbent that are active for use in the purification of sulfur and oxygen-bearing gases comprising: a.
providing a quantity of prepared iron oxide-bearing solids that contain iron sulfates and are suitable in particle size and mechanical properties for contacting with gases, b.
advancing said solids to a decomposition zone, c.
contacting the above solids in the decomposition zone with hot reducing gases to produce a solid that contains magnetite and a product gas that contains both sulfur dioxide and reducing agents, the temperature in the decomposition zone being between about 300.
degree.
and 700.
degree.
C.
d.
separating the magnetite containing solids from the product gas, e.
recovering the product gas containing sulfur dioxide and reducing agents, and f