Improvements in and relating to ammonium sulphate and potassium sulphate

Ammonium and potassium sulphate compositions (either separate, together or in admixture with one or more other substances), may be rendered substantially non-caking by the incorporation of a cerium or thorium compound, whose proportion by weight lies in the range 0,001-0,1%. The additive should have a uniform distribution over the surfaces of the particles of the composition being treated and should be either sprayed in concentrated solution on to the solid composition, mixed in the solid state with the solid composition, or when dealing with a mixture of ammonium and potassium sulphates only it may be added to a slurry of these salts. Specific additives mentioned are ceric sulphate, oxide and hydroxide, cerous nitrate, ammonium ceric sulphate and p nitrate, the nitrates and sulphates of thorium, ammonium thorium nitrate and sulphate. These are compared with the ineffective additives cupric, zinc and magnesium chlorides. Examples relate to ammonium sulphate and potassium sulphate, alone or in admixture, ammonium sulphate plus potassium chloride and ammonium sulphate plus ammonium chloride and potassium chloride being treated with the above additives.