盐酸分解高硅混合型胶磷矿工艺研究

中低品位磷矿的开发利用是中国磷化工产业可持续发展的基本保障。采用盐酸浸取高硅磷矿,通过单因素实验对其酸解工艺和过滤强化过程做了研究。结果表明,磷矿粒径≤180 μm、在反应温度为40 ℃、酸比（实际投入的盐酸量与理论耗酸量的质量比）为1.1、盐酸质量分数为20%以上、浸取10 min,此时P₂O₅浸取率可达到99%以上。盐酸浸取速率快,酸解率高。高硅磷矿酸解料浆中二氧化硅含量高、粒度小、沉降速度慢,导致过滤困难。添加非离子型聚丙烯酰胺絮凝剂,控制絮凝剂为酸解料浆质量的1.0%,沉降2 min之后,可显著强化过滤。

Study on process of hydrochloric acid leaching high silicon mixed phosphate ore

The development and utilization of middle/low-grade phosphate rock is the basic guarantee for the sustainable development of China′s phosphate chemical industry.High silicon phosphate ore was leached by hydrochloric acid,and its acidolysis process and filtration strengthening process were studied by single factor experiment.The results showed that under the optimal conditions,such as phosphate ore particle size was less than 180μm,reaction temperature was 40℃,hydrochloric acid ratio(the mass ratio of actual hydrochloric acid input to theoretical acid consumption)was 1.1,HCl mass fraction was more than 20%,leaching time was 10 min,then the leaching extent of P2O5 was more than 99%.The leaching rate of phosphate ore in hydrochloric acid is fast and the leaching extent is high.The content of silicon dioxide in acidolysis slurry of high silicon phosphate rock is high,with small particle size and slow settling rate in the acidolysis slurry make it difficult to filter.By adding non-ionic polyacrylamide flocculant,the mass of flocculant was controlled to be 1.0%of the quality of acidolysis slurry and settling for 2 min,the filtration was strengthened significantly.