钾长石与磷矿共酸浸制NPK复合肥研究

用磷酸浸取钾长石与磷矿混合物，经水浸取酸浸产物后再用氨水中和制备NPK复合肥和长效磷肥，或制备速效和长效性能兼有的复合肥料。主要研究了钾长石与磷矿共酸浸产物水浸工艺、浸取液氨化工艺。结果表明：水浸适宜条件为温度70℃，浸取时间100min，1g原料浸取水量10mL；氨化终点pH值在6左右时，整个过程钾总收率在84％以上，磷总收率在85％以上。

Study of Manufacture of NPK Compound Fertilizers by Acid Leaching of Potash Feldspar and Phosphate Rock

A mixture of potash feldspar and phosphate rock is leached with phosphoric acid, the acid leached product is leached with water, and then neutralized with aqua ammonia to give NPK compound fertilizers and controlled release phosphatic fertilizers, or compound fertilizers with both quick- and long-acting properties. The study is carried out mainly of the water-leaching process for the acid leach of potash feldspar and phosphate rock as well as the ammoniation process for the leach liquor. The results show that the suitable conditions for water leaching are the temperature at 70 ℃, the leaching time of 100 min, and 10 mL of leaching water for 1 g of raw material. When the pH value at the end point of ammoniation is about 6, the overall yield of potassium in the whole process is over 84% and that of phosphorus over 85%.