PROCESS FOR THE MANUFACTURE OF BIO-RELEASE FERTILIZERS OF ZINC- IRON-MANGANESE IRON-MANGANESE- COPPER AND ZINC- IRON-MANGANESE- COPPER

摘要

A process for the preparation of water insoluble bio-release micronutrientfertilizers containing iron and manganese with either zinc and/or copper whichcomprises :a)heating phosphoric acid with a mixture of (i) oxide of iron compound selected fromgoethite or hematite, (ii) manganese dioxide or pyrolusite, and (iii) either or bothcompound of zinc or copper selected from zinc ash or zinc oxide and cupric oxideor cupric sulphate and (iv) a basic compound like oxide or carbonate of magnesiumcalcium.b)neutralisation followed by drying and pulverisation.