GB156124A - Process for the manufacture of phosphatic manures - Google Patents

Abstract

Phosphates are rendered colloidal by a process of "intensive high-speed mechanical disintegration," as defined in the prior Specification 155,836. The phosphate is disintegrated in a high-speed mill with a large quantity of water to which has preferably been added a small amount of acid or alkali; sulphuric, nitric, phosphoric and other mineral acids are suitable. The finely-divided phosphate becomes hydrated and colloidal and after drying is equal in value to water-soluble phosphates. The process is facilitated by conducting it under pressure or by heating to about 90-95 DEG C., or by adding protective colloids such as tannin, salts of lysalbinic acid, or the alkali salts of humic acid. Bone-meal and guano may be subjected to the same process. In an example slag phosphate is first ground in a phosphate mill and is then disintegrated under the conditions described in the prior Specification, in the presence of six times its amount of water. The resulting suspension is coagulated by means of a gaseous or liquid acid and allowed to separate into two layers. The bottom layer of phosphate mud is withdrawn, filtered and dried, preferably by blowing with hot air or by heating with waste gases.ALSO:Calciumphosphate is rendered assimilable, as a manure, by a process of "intensive high-speed mechanical disintegration" as defined in the prior Specification 155,836, [Class 1 (i), Chemical processes &c.]. The phosphate is disintegrated in a high-speed mill with a large quantity of water to which a small amount of acid or alkali has preferably been added; sulphuric, nitric, phosphoric and other mineral acids are suitable. The finely-divided phosphate becomes hydrated and colloidal and after drying is equal in value to water-soluble phosphates. The process is facilitated by conducting it under pressure or by heating to about 90-95 DEG C., or by adding protective colloids such as tannin, salts of lysalbinic acid, or the alkali salts of humic acid. Bone-meal and guano may be subjected to the same process. In an example slag phosphate is first ground in a phosphate mill and is then disintegrated under the conditions described in the prior Specification in the presence of six times its amount of water. The resulting suspension is coagulated by means of a gaseous or liquid acid and allowed to separate into two layers. The bottom layer of phosphate mud is withdrawn, filtered and dried; preferably by blowing with hot air or by heating with waste gases.