Process for pelleting urea formaldehyde controlled-release compound fertilizer in high tower

Abstract

The invention discloses a process for pelleting urea formaldehyde controlled-release compound fertilizer in a high tower, comprising the following processing steps: A, fusing urea; B, mixing with potassium; C, mixing with phosphorus; D, mixing with formaldehyde: mixing the formaldehyde with caustic soda at normal temperature to obtain formaldehyde mixed liquor, enabling the formaldehyde mixed liquor and mixed fusing slurry to flow into a material receiving container, and mixing at the temperature of 80-110 DEG C to form formaldehyde-urea mixed liquor; and E, pelleting in the high tower. The invention has the following beneficial effects: 1, the compound fertilizer provided by the process of the invention contains urea formaldehyde, becomes silk-screen pasty after being dissolved in water,can be absorbed into soil, is difficult to volatilize or run away, can improve the fertilizer utilization ratio by 5-20%, completely accord with the characteristics of urea formaldehyde controlled-release fertilizer and play a role in retaining nitrogen; 2, the compound fertilizer provided by the process of the invention has high grain density, has small possibility of agglomeration, can reduce adhesion and scabbing of equipment, and has high molding ratio and less returned materials; 3, production is not influenced by high-temperature and high-humidity climate and can be carried out in all-weather conditions; and 4, the compound fertilizer is uniformly pelleted and has beautiful appearance.

Description

technical field

[0001] The invention relates to the field of agricultural fertilizer processing technology. It specifically relates to a high-tower compound fertilizer granulation process. Background technique

[0002] The currently known high-tower compound fertilizer granulation process includes pulping and granulation. The pulping is a three-step series continuous and gradual cooling pulping method, including the following process steps:

[0003] A. Urea melting: Add flux and solid urea to the melting tank, and melt the solid urea at a temperature of 120-130°C;

[0004] B. Potassium mixing: pour molten urea into the first reaction tank, then add potassium chloride, ammonium chloride and fillers into the first reaction tank, and mix with molten urea at a temperature of 110-120°C;

[0005] C. Phosphorus mixing: Flow the mixed material in the first reaction tank into the second reaction tank, then add monoammonium phosphate into the second reaction tank, and mix with the m...