磷钾伴生矿酸解提取磷钾的过程研究

Extraction of Phosphorus and Potassium by acid from a complex Phosphoric Mineral

采用H_2SO_4分解高温焙烧后的磷钾伴生矿,提出直接分离P_2O_5和K_2O,制备复合化肥的工艺。研究过程考察了不同硫酸浓度、粒度、反应温度及搅拌转速对磷、钾浸出过程的影响。结果表明,当硫酸浓度为5%时,酸解产物Ca SO_4的结晶度不完全,随着硫酸浓度的增大,CaSO_4的晶须逐渐长大变粗壮,而当硫酸浓度为30%时,原有的粗大CaSO_4晶须断裂、变短;不同粒径下的焙烧渣成分不同,当颗粒的粒径大于325μm时,其P_2O_5的含量可达8.39%,而75μm以下的颗粒中仅含2.99%的P_2O_5。当在硫酸浓度为20%,搅拌转速为200 r/min,反应时间60 min,反应温度为80℃条件下,P_2O_5和K_2O的浸出率可达90%以上。

The process of separating P_2O_5 and K_2O by sulfuric acid leaching roasted phosphate was proposed to prepare compound fertilizers. The effect of stirring speed, H_2SO_4 concentration, particle size and reaction temperature on the leaching process was researched. The results indicate that when the concentration of sulfuric acid is 5%, the crystallinity of acid hydrolysate CaSO_4 was not complete; with the concentration of sulfuric acid increasing, the whiskers of CaSO_4 gradually grow and become thicker; when the sulfuric acid concentration is 30%, the original coarse CaSO_4 whiskers are broken and shortened. Meanwhile, the chemical composition of the roasted slag in different particle size is various. When the particle size is larger than 325 μm, the content of P_2O_5 is 8.39%, while that of 75 μm or less is only 2.99%. In the condition of 20% sulfuric acid concentration, 200 rpm, 60 min, 80℃, both the leaching rate of P_2O_5 and K_2O can reach 90%.