液态聚醚/丙二醇提高铁精矿滤饼结构渗透性

Permeability of Iron Concentrate Filter Cake Structure Improved by Liquid Polyether / Propylene

针对铁精矿滤饼颗粒微细、孔道狭窄、过滤脱水困难这类问题,采用5种不同类型的助滤剂,对铁精矿进行助滤脱水试验。结果表明,液态聚醚的助滤效果优于其余助滤剂,在铁精矿中添加150 g/t(按干物料计)液态聚醚,滤饼水分从14.74%降至10.2%,过滤速度提高1.3倍。为进一步优化过滤性能,对液态聚醚进行复配试验,结果表明液态聚醚与丙二醇配合使用时(液态聚醚∶丙二醇质量比7∶3),助滤效果最佳,当药剂投加量为150 g/t时,滤饼水分降至8.35%,过滤速度提高1.5倍。液态聚醚在铁精矿颗粒表面形成“蘑菇”型吸附,使颗粒间产生位阻排斥作用,造成滤饼结构蓬松。通过X射线CT扫描滤饼结构,结果表明,加入液态聚醚/丙二醇后滤饼的孔隙率增加、迂曲度减少、盲孔数量减少,有助于水分的迁移。本研究为提高铁精矿过滤速度、降低滤饼水分提供了新思路。

In response to the problem that iron ore concentrate filter cake has fine particles and narrow pore channels,which makes filtration and dewatering difficult,filtration and dewatering tests were conducted on iron ore concentrate with five different types of filter aids.The test results showed that the filtering aid effect of liquid polyether was better than other filtering aids;adding 150 g/t(in terms of dry material)of liquid polyether to iron ore concentrate,the filter cake moisture decreased from 14.74%to 10.2%and the filtration speed increased by 1.3 times.To further optimize the filtration performance,the liquid polyether was compounded.The results show that when liquid polyether and propylene glycol are used together(liquid polyether∶propylene glycol mass ratio 7∶3),the effect is the best;when the agent dosage is 150 g/t,the filter cake moisture can be reduced to 8.35%and the filtration speed can be increased by 1.5 times.It was found that the liquid polyether produced"mushroom"type adsorption on the surface of iron ore concentrate particles,which expanded the particle-to-particle distance in the filter cake structure,thus facilitating the filtration process.Finally,the filter cake structure was scanned by X-CT.The CT results showed that the porosity of the filter cake increased after the addition of liquid polyether/propylene glycol,the tortuosity decreased,and the number of blind pores decreased,which helped the migration of water.This study provides a new idea to improve the filtration rate of iron ore concentrate and reduce the moisture of the filter cake.