某提铁降杂独立精选厂的工艺设计与生产实践

山西某地有着为数众多的磁铁矿小型选厂，产出的弱磁选铁精矿铁品位仅61%～58%、SiO₂含量达12%～15%，不符合高炉炼铁的精料方针，严重影响销售。为此，在试验研究的基础上，采用反浮选-中矿再磨-弱磁选工艺及可在常温下进行浮选的高效阴离子捕收剂LP-4，结合当地实际情况设计、建设了对这些弱磁选铁精矿集中进行提铁降杂的独立精选厂。生产实践表明，该独立精选厂工艺流程运行稳定，适应性强，可使最终精矿铁品位达到67.2%～66.5%，SiO₂含量降至5.2%～5.8%，提铁降杂效果良好。

Research & Design of the Beneficiation Process for Separate Quality Improvement & Impurities Reduction of Iron Concentrate and Its Application Practice

There are a number of small sized magnetite ore concentrators in a region in Shanxi, which produce iron concentrates by low intensity magnetic separation that have an iron grade of only 61%～58% but an SiO₂ content as high as 12%～15%, not conforming to the guideline of good burden preparation for blast furnace iron-making and seriously affecting their sales. Based on the experimental research and in light of the local real conditions, a separate concentrator for their upgrading has been designed and built for a centralized treatment of these iron concentrates, which adopts a process consisting of reverse flotation, middling regrinding and low magnetic separation, and a high efficient anionic collector LP-4 that can be used in normal temperature. Now, this separate concentrator is running stably and has a good adaptability. It is capable to raise the iron grade of the concentrate to 67.2%～66.5%and reduce the SiO₂ content to 5.2%～5.8%, demonstrating a good effect of quality improvement and impurity reduction.