A homogeneous fertilizer granule comprises slow-release (e.g. struvite) and fast release sources of phosphorus (P). The homogeneous fertilizer granule may further contain other essential nutrients and micronutrients required by plants. A number of methods may be used to make such granules. One method includes introducing a struvite slurry or fines and a liquid supply of water soluble P into a granulator. Alternatively, dry raw materials can be mixed with water/steam and/or another binder prior to being fed into a granulator. In another embodiment, pre-mixed dry raw materials are mechanically compacted and crushed to yield homogeneous fertilizer particles.

A homogeneous fertilizer granule comprises slow-release (e.g. struvite) and fast release sources of phosphorus (P). The homogeneous fertilizer granule may further contain other essential nutrients and micronutrients required by plants. A number of methods may be used to make such granules. One method includes introducing a struvite slurry or fines and a liquid supply of water soluble P into a granulator. Alternatively, dry raw materials can be mixed with water/steam and/or another binder prior to being fed into a granulator. In another embodiment, pre-mixed dry raw materials are mechanically compacted and crushed to yield homogeneous fertilizer particles.

Fertilizer granules containing elemental sulfur and a hydrogel which expands or swells in the soil to more readily disperse the elemental sulfur surface throughout the soil, which increases the elemental sulfur surface area available for oxidation, and ultimately uptake of sulfur by the plant. The elemental sulfur and hydrogel can be added to a fertilizer composition as either an exterior coating or co-granulated with the base fertilizer composition.

Fertilizer granules containing elemental sulfur and a hydrogel which expands or swells in the soil to more readily disperse the elemental sulfur surface throughout the soil, which increases the elemental sulfur surface area available for oxidation, and ultimately uptake of sulfur by the plant. The elemental sulfur and hydrogel can be added to a fertilizer composition as either an exterior coating or co-granulated with the base fertilizer composition.

Novel granular fertilizers and methods of making those fertilizers are provided. The method utilized involves recycling streams, including one that provides water having dissolved solids therein, with that water being used during the mixing and granulation process. This method results in a low-moisture, hard, substantially spherical granule, which can include any number of macronutrients and/or micronutrients. Advantageously, the granular fertilizer can be applied to the soil around plants to supply those plants with the necessary nutrients.

Granular fertilizer compositions are described herein that are capable of supplying a wide array of beneficial nutrient and compounds to soil for uptake by the root systems of plants. In preferred embodiments, the compositions provide a source of phosphorus, a source of nitrogen, a source of boron, a source of copper, a source of manganese, a source of zinc, and a source of sulfur in a single application, with highly efficient uptake by plants. The compositions generally comprise a mixture of two or three types of granules, each providing a supply of one or more nutrients. It has been discovered that the components of the three types of granules interact in a synergistic manner, such that problems associated to with certain nutrients in soil are overcome, thereby providing a highly efficient multi-nutrient fertilizer.

Granular fertilizer compositions are described herein that are capable of supplying a wide array of beneficial nutrient and compounds to soil for uptake by the root systems of plants. In preferred embodiments, the compositions provide a source of phosphorus, a source of nitrogen, a source of boron, a source of copper, a source of manganese, a source of zinc, and a source of sulfur in a single application, with highly efficient uptake by plants. The compositions generally comprise a mixture of two or three types of granules, each providing a supply of one or more nutrients. It has been discovered that the components of the three types of granules interact in a synergistic manner, such that problems associated to with certain nutrients in soil are overcome, thereby providing a highly efficient multi-nutrient fertilizer.

Novel granular fertilizers and methods of making those fertilizers are provided. The method utilized involves recycling streams, including one that provides water having dissolved solids therein, with that water being used during the mixing and granulation process. This method results in a low-moisture, hard, substantially spherical granule, which can include any number of macronutrients and/or micronutrients. Advantageously, the granular fertilizer can be applied to the soil around plants to supply those plants with the necessary nutrients.

The invention relates to a method for manufacturing an ammonium phosphate fertilizer from a phosphoric acid aqueous solution that has less than 50% P.sub.2O.sub.5 concentration and is obtained by wet phosphate ore treatment, said phosphoric acid containing traces of cadmium, comprising the following steps: (a) neutralizing said phosphoric acid solution (1) with ammonia (3) up to a molar ratio N/P of between 0.1 and 0.8, (b) reacting said partially neutralized solution (4) with a sulfide source (6) so as to form a cadmium sulfide precipitate (9), (c) separating said precipitate (9) so as to obtain a refined ammoniated phosphoric acid solution (10), (d) ammoniating and granulating said refined solution (10) so as to form said fertilizer (12).

The invention relates to a method for manufacturing an ammonium phosphate fertilizer from a phosphoric acid aqueous solution that has less than 50% P.sub.2O.sub.5 concentration and is obtained by wet phosphate ore treatment, said phosphoric acid containing traces of cadmium, comprising the following steps: (a) neutralizing said phosphoric acid solution (1) with ammonia (3) up to a molar ratio N/P of between 0.1 and 0.8, (b) reacting said partially neutralized solution (4) with a sulfide source (6) so as to form a cadmium sulfide precipitate (9), (c) separating said precipitate (9) so as to obtain a refined ammoniated phosphoric acid solution (10), (d) ammoniating and granulating said refined solution (10) so as to form said fertilizer (12).