Spheroidally agglomerated basic cobalt(II) carbonate and spheroidally agglomerated cobalt(II) hydroxide, a process for producing them and their use

Abstract

The present invention relates to basic cobalt(II) carbonate, agglomerated from fine primary particles and of general composition Co[(OH) 2 ] a [CO 3 ] 1-a , where 0.1≦a≦0.9, and to spherodial cobalt(II) hydroxide, to a process for producing them and to their use.

1 . Basic cobalt(II) carbonate, agglomerated from fine primary particles and of general composition Co[(OH) 2 ] a [CO 3 ] 1-a , where 0.1≦a≦0.9, characterised in that the agglomerates have a spheroidal habit and the average agglomerate diameter is 3 to 50 μm.  
     
     
         2 . Basic cobalt(II) carbonate agglomerates according to  claim 1 , characterised in that the agglomerate diameter is 5-20 μm.  
     
     
         3 . Basic cobalt(II) carbonate agglomerates according to either one of claims  1  or  2 , characterised in that they have tap densities of ≧1.6 g/cm 3  and bulk densities of ≧1.2 g/cm 3 .  
     
     
         4 . A process for producing basic cobalt(II) carbonate agglomerates, according to one or more of  claims 1  to  3 , characterised in that aqueous solutions of cobalt salts of general formula CoX 2 , where X represents Cl—, NO 3 — and/or ½ SO 4   2- , are reacted with aqueous solutions or suspensions of alkali and/or ammonium carbonates and/or hydrogen carbonates at temperatures between 40 and 100° C., preferably 60 to 90° C., and the resulting basic cobalt(II) carbonate agglomerates are subsequently filtered off and washed until they are neutral and free from salts.  
     
     
         5 . A process for producing agglomerated cobalt(II) hydroxide, characterised in that basic cobalt(II) carbonate agglomerates according to one or more of  claims 1  to  4  are reacted in suspension with aqueous alkaline liquors and/or ammonia.  
     
     
         6 . Cobalt(II) hydroxide, obtainable according to one or more of claims  4  or  5 , characterised in that it consists of spheroidally agglomerated, polygonal, lamellar primary particles which have average diameters of 0.3 μm to 1.5 μm and diameter to thickness ratios between 3 and 15.  
     
     
         7 . Cobalt(II) hydroxide according to  claim 6 , characterised in that the spheroidal agglomerates have an average diameter of 3-50 μm, preferably 5-20 μm.  
     
     
         8 . Cobalt(II) hydroxide according to either one of claims  6  or  7 , characterised in that it has tap densities of ≧1 g/cm 3 .  
     
     
         9 . Use of the basic cobalt(II) carbonate agglomerates according to one or more of  claims 1  to  4  for the production of spheroidal, free-flowing cobalt(II) oxide and higher oxides.  
     
     
         10 . Use of the basic cobalt(II) carbonate agglomerates according to one or more of  claims 1  to  4  for the production of pure cobalt(II) salts for use in catalyst technology or in bonding agents.  
     
     
         11 . Use of cobalt(II) hydroxides according to one or more of  claims 5  to  8  as components of the nickel oxide electrode in alkaline secondary cells.  
     
     
         12 . Use of cobalt(II) hydroxide according to one or more of  claims 5  to  8  for the production of pure cobalt(II) salts for use in bonding agents and catalysts.  
     
     
         13 . Use of cobalt(II) hydroxide according to one or more of  claims 5  to  8  for the production of spheroidal, free-flowing cobalt(II) oxide or higher oxides by calcination.  
     
     
         14 . Use of basic cobalt(II) carbonate agglomerates according to ore or more of  claims 1  to  4  and/or cobalt(II) hydroxide according to one or more of  claims 5  to  8  for the production of cobalt pigments.