Abstract: NP- or NPK-containing fertilizers are manufactured from low-grade phosphate ore digested by nitric acid. Substantial problems have been experienced during previous attempts to produce fertilizers from phosphate ore having a high content of magnesium. The problems relate to the solution's viscosity, which becomes extremely high during neutralization with ammonia of the mother liquor, obtained by removal of most of the calcium as calcium nitrate-tetrahydrate from the digested phosphate. The novel process solves the viscosity problems by adjusting the conditions during ammoniation and the subsequent evaporation before prilling or granulation. The adjustment is characterized in that a substantial part of the remaining calcium is kept outside the process itself, at least during the neutralization and evaporation stages.

Abstract: A process for the ammoniation of straw and other plant materials containing lignocellulose with a dry matter content of at least 60%, utilizing anhydrous ammonia, preferably in liquid form. The plant material is covered by a gas impervious material and ammonia is added in excess of the amount needed for optimal irreversible nitrogen binding, preferably from 20-35 kg NH.sub.3 /ton dry matter, without application of external heat and pressure. The ammonia impregnated material is left at ambient temperature for at least 10 days, whereafter it is vented and ready for use. The preferred use of the ammoniated straw is as an animal feed.