Granular phosphate fertiliser prodn. - by igniting a granulated mixture of sand, soda and apatite

摘要

In the prodn. of "Rhe-Ka-Phos" phosphatic fertilizer, a mixture of apatite, soda and sand in granulated form is used as raw material. The raw material is pref. in the form of pressings with a hardness of >20 kp/cm2. The pressings are produced from apatite with a particle size 0.1-0.4mm, sand with a particle size of 0.1-0.4mm and soda with a particle size of 0.05-0.4mm. The production process involves igniting the raw materials in an oven. Use of granulated raw materials reduces dust formation, improves heat transfer, and gives controlled sintering so that a free-flowing product is obtained. Granulation of raw materials gives a 20% increase in the capacity of the rotary ovens used for sintering.