Patent GB-373211-A (GB)
Title: Improvements in the manufacture and production of non-caking mixed fertilisers containing ammonium nitrate
IPC: C05C1/02
Filed: 1931-02-11
Abstract: Non-caking mixed fertilizers containing ammonium nitrate, e.g fertilizers containing ammonium nitrate and ammonium sulphate, are made by adding to or incorporating with the mixed fertilizer non-deliquescent salts of aluminium, or of iron, which in the anhydrous state have the property of being capable of taking up water as water of crystallization, preferably in an amount between 1-10 per cent by weight of the mixed fertilizers.  Salts specified are the sulphates, ferric citrate, non-deliquescent double salts, e.g. aluminium ammonium alum, iron aluminium alum, ferrous ammonium sulphate (Mohr's salt), potassium aluminium sulphate, sodium iron sulphate, magnesium aluminium sulphate, sodium aluminium sulphate, sodium aluminium borate, the double salt <FORM:0373211/III/1> Alternatively sulphates of iron may be formed in the mixed fertilizers by the interaction of sulphates, e.g. those of ammonium, potassium, sodium, divalent iron, zinc, and manganese with the liquid rich in ferric hydroxide hydrosol which is obtained by adding to ferrous sulphate containing water of crystallization an amount of nitric acid which is insufficient for the complete conversion into ferric salts.  The additional salts may be added in a completely or partially dehydrated state or as the completely hydrated salts or in a dissolved form, provided the product is subjected to a subsequent drying operation to remove some of the water of crystallization, e.g. they may be added in a dissolved or solid form to the dissolved or fused fertilizers or sprayed on to the fertilizers in the form of concentrated solutions or mixed in the wholly or partly dehydrated form with the finished fertilizers.  Specification 372,388 is referred to.ALSO:Non-caking mixed fertilizers containing ammonium nitrate, e.g fertilizers containing ammonium nitrate and ammonium sulphate, are made by adding to or incorporating with the mixed fertilizer non-deliquescent salts of aluminium or of iron, which in the anhydrous state have the property of being capable of taking up water as water of crystallization, preferably in an amount between 1-10 per cent by weight of the mixed fertilizers.  Salts specified are the sulphates, ferric citrate, non-deliquescent double salts, e.g. aluminium ammonium alum, iron aluminium alum, ferrous ammonium sulphate (Mohr's salt), potassium aluminium sulphate, sodium iron sulphate, magnesium aluminium sulphate, sodium aluminium sulphate, sodium aluminium borate, the double salt 6FeSO4, F Fe2(SO4)310H2O. Alternatively sulphates of iron may be formed in the mixed fertilizers by the interaction of sulphates, e.g. those of ammonium, potassium, sodium, divalent iron, zinc and manganese with the liquid rich in ferric hydroxide hydrosol which is obtained by adding to ferrous sulphate containing water of crystallization an amount of nitric acid which is insufficient for the complete conversion into ferric salts.  The additional salts may be added in a completely or partially dehydrated state or as the completely hydrated salts or in a dissolved form, provided the product is subjected to a subsequent drying operation to remove some of the water of crystallization, e.g. they may be added in a dissolved or solid form to the dissolved or fused fertilizers or sprayed on to the fertilizers in the form of concentrated solutions or mixed in the wholly or partly dehydrated form with the finished fertilizers.  Specification 372,388 is referred to.