Properties and activity of zinc chemisorbents on carriers

In the preparation of zinc alumocalcium chemisorbents, reactions take place during mixing of the zinc component with the carrier in the aqueous ammonium medium, which lead to the formation of phases of zinc hydroxoaluminate, gibbsite, zinc hydroxide, calcite, an ammonia-carbonate zinc complex, and tricalcium aluminate hexahydrate. The degree of combination of the zinc component into the zinc hydroxoaluminate depends on the degree of hydration of the carrier and decreases in the order: calcium monoaluminate > calcium dialuminate > aluminum oxide > Galumin. In the thermolysis the zinc hydroxoaluminate is converted to dispersed zinc oxide and disordered zinc-aluminum spinel, the amount of which depends on the nature of the carrier. The sulfur capacity of the zinc chemisorbents depends on the zinc oxide content and on the amount of the free zinc oxide phase; it changes antibatically to the ability of the carrier to bind the zinc component into zinc hydroxoaluminate and zinc-aluminum spinel.