冷冻法硝酸磷肥副产粗硝钙液用于磷矿脱镁的研究

针对冷冻法硝酸磷肥副产粗硝钙液中的磷进入滤渣难以回收利用导致硝酸磷肥装置产能低、胶磷矿富集技术浸取工段氨逃逸率低致使浸取液中硝酸铵含量高造成下游无法使用的问题,开展了粗硝钙液用于磷矿脱镁的研究。实验方法及最优反应条件：原矿经破碎、煅烧（煅烧温度为900~1 100 ℃,煅烧时间为1.5~3.0 h）,用粗硝钙液浸取,利用粗硝钙液的热能和化学反应热控制反应温度为60~70 ℃（不需加热,节省了蒸汽消耗）,反应pH为4.5~6.5,反应过程中无磷析出。在此条件下制取的磷精矿中五氧化二磷质量分数≥35%、氧化镁质量分数≤1.0%,磷回收率为100.49%~100.60%。将制取的磷精矿进行酸解,提高了酸不溶物的分离效率,可满足下游生产白色硝酸磷肥对原料的要求,副产的浸取液可用于生产氨基酸液体肥和中量元素营养母粒。该方法无尾矿产生,绿色环保,为磷矿的高效利用提供了新的研究思路。

Study on by-product crude calcium nitrate solution of frozen nitrophosphate fertilizer for phosphate rock demagnesium

In view of the fact that the phosphorus in the by-product crude calcium nitrate solution of frozen nitrophosphate en-ters the filter residue and is difficult to be recycled,the production capacity of the nitrophosphate fertilizer plant is low,and the ammonia escape rate in the leaching section of the collophanite enrichment technology is low,which leads to the high content of ammonium nitrate in the leaching solution,causing the the question of unable to be used in downstream. Study on the use of crude calcium nitrate solution for phosphate rock removal was carried out.Experimental method and optimal reac-tion conditions：the raw ore was crushed and calcined（calcination temperature was 900~1 100 ℃,calcining time was 1.5~3.0 h）,leached with crude calcium nitrate solution,using the thermal energy and chemical reaction of the crude calcium ni-trate solution The thermal control reaction temperature was 60~70 ℃,which saved steam consumption and didn′t need heat-ing.The reaction pH was 4.5~6.5,and no phosphorus was precipitated during the reaction.In the phosphate concentrate pre-pared under these conditions,the mass fraction of phosphorus pentoxide was≥35%,the mass fraction of magnesium oxide was≤1.0%,and the phosphorus recovery rate was 100.49%~100.60%.The phosphate concentrate produced by this technolo-gy was acidified.The separation efficiency of acid-insoluble matter was improved,which could meet the raw material require-ments for downstream production of white nitrophosphate.The by-product extract could be used to produce amino acid liquid fertilizer and medium element nutrient masterbatch.The method had no tailings,which was green and environmentally friend-ly,and provided a new research idea for the efficient utilization of phosphate rock.