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).

The invention relates to a method for preparing an aqueous suspension of at least one phosphate material, comprising, dispersing, in water, particles of phosphate material in the presence of at least one additive of the anionic polymer of acrylic acid or of methacrylic acid type. The suspension according to the invention has a viscosity of less than 1500 mPa.Math.s. The invention also relates to the conditioning of the phosphate material associated with the anionic polymer, for its subsequent treatment with at least one strong acid, for the industrial preparation of phosphoric acid.

The present invention provides a method for the preparation of multi-nutrient potassic fertilizer, by recovering potassium from sugarcane molasses based alcohol distillery effluent (commonly known as spent wash). The process involves pre-treatment of spent wash to clarify the aqueous phase and utilization of the treated spent wash in production of potassic fertilizer. The present invention enables utilisation of spent wash for recovery of value-added product (viz., potash fertiliser of >99% purity) and improves ease of Zero Liquid Discharge compliance by subjecting the relatively benign process effluent to industrially practiced techniques for water recovery and salt reclamation.

The present invention provides a method for the preparation of multi-nutrient potassic fertilizer, by recovering potassium from sugarcane molasses based alcohol distillery effluent (commonly known as spent wash). The process involves pre-treatment of spent wash to clarify the aqueous phase and utilization of the treated spent wash in production of potassic fertilizer. The present invention enables utilisation of spent wash for recovery of value-added product (viz., potash fertiliser of >99% purity) and improves ease of Zero Liquid Discharge compliance by subjecting the relatively benign process effluent to industrially practiced techniques for water recovery and salt reclamation.

A method of processing a powder, comprising (a) contacting the powder with (i) a 2-40% by weight solution of a sulphur- or phosphorous-containing mineral acid or a mixture thereof, or (ii) one or more alkaline earth metal oxides, carbonates or hydroxides, or a mixture thereof; (b) combining the product of (a)(i) with one or more alkaline earth metal oxides, carbonates or hydroxides, or a mixture thereof; or combining the product of (a)(ii) with a 2-40% by weight solution of a sulphur- or phosphorous-containing mineral acid or a mixture thereof and optionally with further of the alkaline earth metal oxides, carbonates or hydroxides, or a mixture thereof; and (c) granulating the combination of (b) to form granules.

Phosphate- and potassium-containing fertilisers are made using the granules.

A method of processing a powder, comprising (a) contacting the powder with (i) a 2-40% by weight solution of a sulphur- or phosphorous-containing mineral acid or a mixture thereof, or (ii) one or more alkaline earth metal oxides, carbonates or hydroxides, or a mixture thereof; (b) combining the product of (a)(i) with one or more alkaline earth metal oxides, carbonates or hydroxides, or a mixture thereof; or combining the product of (a)(ii) with a 2-40% by weight solution of a sulphur- or phosphorous-containing mineral acid or a mixture thereof and optionally with further of the alkaline earth metal oxides, carbonates or hydroxides, or a mixture thereof; and (c) granulating the combination of (b) to form granules.

Phosphate- and potassium-containing fertilisers are made using the granules.

A method of processing a powder, comprising (a) contacting the powder with (i) a 2-40% by weight solution of a sulphur- or phosphorous-containing mineral acid or a mixture thereof, or (ii) one or more alkaline earth metal oxides, carbonates or hydroxides, or a mixture thereof; (b) combining the product of (a)(i) with one or more alkaline earth metal oxides, carbonates or hydroxides, or a mixture thereof; or combining the product of (a)(ii) with a 2-40% by weight solution of a sulphur- or phosphorous-containing mineral acid or a mixture thereof and optionally with further of the alkaline earth metal oxides, carbonates or hydroxides, or a mixture thereof; and (c) granulating the combination of (b) to form granules.

Phosphate- and potassium-containing fertilisers are made using the granules.

The present invention provides a method for the preparation of multi-nutrient potassic fertilizer, by recovering potassium from sugarcane molasses based alcohol distillery effluent (commonly known as spent wash). The process involves pre-treatment of spent wash to clarify the aqueous phase and utilization of the treated spent wash in production of potassic fertilizer. The present invention enables utilisation of spent wash for recovery of value-added product (viz., potash fertiliser of >99% purity) and improves ease of Zero Liquid Discharge compliance by subjecting the relatively benign process effluent to industrially practiced techniques for water recovery and salt reclamation.

The present invention provides a method for the preparation of multi-nutrient potassic fertilizer, by recovering potassium from sugarcane molasses based alcohol distillery effluent (commonly known as spent wash). The process involves pre-treatment of spent wash to clarify the aqueous phase and utilization of the treated spent wash in production of potassic fertilizer. The present invention enables utilisation of spent wash for recovery of value-added product (viz., potash fertiliser of >99% purity) and improves ease of Zero Liquid Discharge compliance by subjecting the relatively benign process effluent to industrially practiced techniques for water recovery and salt reclamation.