METHOD OF PRODUCING LOW-BALLAST AMMONIUM HUMATE Russian patent published in 1997 - IPC

FIELD: fertilizers production. SUBSTANCE: invention relates to producing low-ballast and ballast-free ammonium humate from brown coal to be used as plant stimulants and microfertilizers in agriculture and landscaping. Humates are isolated in three-step process. In the first step, coal is treated with ammonia solution in continuous mill-activator with solids to liquid phase weight ratio 1:3 and ammonia content corresponding to 8% based on dry coal weight. To resulting suspension, water is added to achieve solids to liquid phase weight ratio 1:8, whereupon extraction process is carried out in mixer with intensification of physico-chemical processes for 15 min. liquid phase is then separated by centrifugation on continuous centrifuge, and remaining solid phase (residual coal) is additionally treated in the second and third steps, in each of the two solid phase being disintegrated on mill-activator, supplemented with water to achieve above-said ratio 1:8 and further subjected to extraction and liquid phase separation operations. EFFECT: increased yield of humates and improved feasibility of process.