A process for preparing a micronutrient-enriched phosphate-based fertilizer is disclosed. An aqueous fertilizer mixture comprising phosphoric acid and/or phosphate rock is prepared and optionally granulated in granulator unit. The pH of the fertilizer mixture is measured and controlled such that the pH is maintained within a predefined range.

According to some demonstrative embodiments, there is provided herein a spherical fertilizer granule having a specific gravity of more than 1.94 g/cm.sup.2 and less than 3% porosity.

According to some demonstrative embodiments, there is provided herein a spherical fertilizer granule having a specific gravity of more than 1.94 g/cm.sup.2 and less than 3% porosity.

The present invention relates to a method for purifying raw phosphoric acid by adding ashes originating from waste incineration plants, as well as calcium hydroxide and at least one sulfide, and by wet-chemical digestion for obtaining (producing) calcium sulfate, pure phosphoric acid, metal salt solution and/or calcium hydrogen phosphates (e.g. triple superphosphate).

The present invention relates to a method for purifying raw phosphoric acid by adding ashes originating from waste incineration plants, as well as calcium hydroxide and at least one sulfide, and by wet-chemical digestion for obtaining (producing) calcium sulfate, pure phosphoric acid, metal salt solution and/or calcium hydrogen phosphates (e.g. triple superphosphate).

A particulate fertilizer coating composition or a coated fertilizer containing a solid acidic particulate material and a solid basic particulate material. The coating composition and coated fertilizer are each stable, chemical compatible with other fertilizers, and/or are abrasion resistant.

A particulate fertilizer coating composition or a coated fertilizer containing a solid acidic particulate material and a solid basic particulate material. The coating composition and coated fertilizer are each stable, chemical compatible with other fertilizers, and/or are abrasion resistant.

A particulate fertilizer coating composition or a coated fertilizer containing a solid acidic particulate material and a solid basic particulate material. The coating composition and coated fertilizer are each stable, chemical compatible with other fertilizers, and/or are abrasion resistant.

A method of calcination includes providing a raw material including whitlockite Ca.sub.9(Mg,Fe.sup.2+)[PO.sub.3(OH)|(PO.sub.4).sub.6], and/or iron phosphate FePO.sub.4, and/or aluminum phosphate AlPO.sub.4 and/or fluorapatite Ca.sub.5(PO.sub.4).sub.3F; providing an alkaline-sulfuric compound as an additive; and calcining a mixture of the raw material with the additive to obtain a product, including a citrate soluble phosphate compound.

A method of calcination includes providing a raw material including whitlockite Ca.sub.9(Mg,Fe.sup.2+)[PO.sub.3(OH)|(PO.sub.4).sub.6], and/or iron phosphate FePO.sub.4, and/or aluminum phosphate AlPO.sub.4 and/or fluorapatite Ca.sub.5(PO.sub.4).sub.3F; providing an alkaline-sulfuric compound as an additive; and calcining a mixture of the raw material with the additive to obtain a product, including a citrate soluble phosphate compound.