Contact and adsorbent granules

Abstract

The present invention relates to pellets or granules based on iron oxides and/or iron oxyhydroxides and iron(III) hydroxide, a unit suitable for the through-flow of a fluid medium at least partially filled with an adsorbent/catalyst in pellet form consisting essentially of iron oxide and/or iron oxyhydroxide embedded in an iron hydroxide matrix, processes for their production comprising filtering, drying and shaping steps and their processes of their use.

What is claimed is:  
     
         1 . A unit suitable for the through-flow of a fluid medium at least partially filled with an adsorbent/catalyst in pellet form consisting essentially of iron oxide and/or iron oxyhydroxide embedded in an iron hydroxide matrix.  
     
     
         2 . The unit of  claim 1  wherein the medium is a gas.  
     
     
         3 . The unit of  claim 1  wherein the medium is a liquid.  
     
     
         4 . The unit of  claim 3  wherein the medium comprises water.  
     
     
         5 . A water treatment plant comprising the unit of  claim 1 .  
     
     
         6 . A waterwork comprising the water treatment plant of  claim 5 .  
     
     
         7 . A process for the production of an adsorbent/catalyst comprising the steps of 
 (a) mixing an aqueous iron(III) hydroxide suspension into an aqueous suspension of iron oxide and/or iron oxyhydroxide, comprising Fe(OH) 2  and then    (b) either    (b1) drying the suspension until it reaches a solid state and then mechanically comminuting the solid material to the desired shape and/or size,    or    (b2) mechanically shaping the suspension, optionally in the semisolid state after predrying, followed by additional drying until a solid state is achieved.    
     
     
         8 . The process of  claim 7  wherein the iron oxides and/or iron oxyhydroxides comprises structures based on α, β, γ, δ, δ′, ε phases and/or Fe(OH) 2 , ferric hydrite and mixed and intermediate phases thereof.  
     
     
         9 . The process of  claim 7  wherein iron carbonates are used in addition to or instead of the iron oxides and/or iron oxyhydroxides.  
     
     
         10 . The process of  claim 7  wherein commercial pigments are used as iron oxides and/or iron (oxy)hydroxides.  
     
     
         11 . The process of  claim 7  wherein transparent pigments are used as iron oxides and/or iron oxyhydroxides.  
     
     
         12 . The process of  claim 7  further comprising the step of precipitating the Fe(OH) 3  with Fe 3+  salts from the series of carbonates, chlorides, fluorides, nitrates, sulfates and sulfites.  
     
     
         13 . A process comprising treating a fluid medium in a unit according to  claim 1  by contacting the fluid medium with an absorbent/catalyst obtained by a process for the production of an adsorbent/catalyst comprising the steps of 
 (b) mixing an aqueous iron(ill) hydroxide suspension into an aqueous suspension of iron oxide and/or iron oxyhydroxide, comprising Fe(OH) 2  and then  
 (b) either  
 (b1) drying the suspension until it reaches a solid state and then mechanically comminuting the solid material to the desired shape and/or size,  
 or  
 (b2) mechanically shaping the suspension, optionally in the semisolid state after predrying, followed by additional drying until a solid state is achieved.  
 
     
     
         14 . The process of  claim 13  wherein the fluid medium comprises water.  
     
     
         15 . The process of  claim 13  comprising removing a heavy metal, phosphorus, antimony, beryllium, selenium, tellurium or cyano compound from water.  
     
     
         16 . The process of  claim 13  comprising removing an arsenic compound from water.