某石英砂浮选降铁工艺及机理研究

Research on the Flotation Iron Reduction Process and Mechanism of a Certain Quartz Sand

对某石英砂沉降脱泥洗矿后浮选除铁工艺进行研究,考察调浆酸种类、矿浆pH值、调浆时间、捕收剂用量、浮选矿浆浓度等条件对石英砂精矿中铁含量的影响。结果表明:捕收剂采用十二烷基磺酸钠(SDS)反浮选脱除该石英砂中赤铁矿可以达到降铁的目的;浮选降铁较优的工艺条件为,石英砂原矿经脱泥后分级,106~450μm粒级的石英砂入浮,盐酸调节矿浆pH值至3、调浆时间2 min、浮选矿浆浓度20%、捕收剂SDS用量400 g/t、起泡剂松油醇用量25 g/t。最终可获得SiO2含量达98.84%、Fe2O3含量仅0.022%的石英砂精矿,满足无色玻璃工业的入料要求。此外,通过动电位测试发现,矿浆pH值约为3时处于石英和赤铁矿的等电点中间位置,此时捕收剂阴离子会选择性地作用于赤铁矿表面,从机理上初步解释了该pH值条件下赤铁矿得到较好脱除的原因。

A study was conducted on the flotation iron removal of a certain quartz sand after settling,desliming,and washing.The effects of conditions such as the type of slurry acid,slurry pH value,slurry preparation time,collector dosage,and flotation slurry concentration on the iron content in the quartz sand concentrate were investigated.The results showed that using sodium dodecyl sulfonate(SDS)as a collector for reverse flotation to remove hematite from the quartz sand can achieve the goal of reducing iron content;The optimal process conditions for flotation iron reduction are that the quartz sand ore is deslimed and graded,106-450μm grade quartz sand is added for flotation,and hydrochloric acid is used to adjust the pH value of the slurry to 3.The mixing time is 2 minutes,the flotation slurry concentration is 20%,the amount of collector SDS is 400 g/t,and the amount of foaming agent terpineol is 25 g/t.Ultimately,a quartz sand concentrate with a SiO2 content of 98.84%and a Fe2O3 content of only 0.022%can be obtained,meeting the feeding requirements of the colorless glass industry.In addition,through potentiodynamic testing,it was found that when the pH value of the slurry was about 3,it was located in the middle of the isoelectric points of quartz and hematite.At this time,the anions of the collector selectively acted on the surface of hematite,which preliminarily explained the reason for the better removal of hematite under this pH condition from a mechanistic perspective.