聚硅氯化铝的研制及对油田污水的絮凝性能

Preparation and Flocculating Capacity of Polyaluminum Silicate Chloride for Purifying Oilfield Produced Water

根据絮凝剂净化长庆油田含油污水的效果(上清液浊度、透光率,絮体体积、相对沉降速度),实验考察了由试剂偏硅酸和工业品聚合氯化铝制备絮凝剂聚硅氯化铝(PASC)的条件。结果表明,以30%Na2SiO3溶液和30%H2SO4溶液按体积比1∶2进行反应,最佳硅酸聚合(凝胶)时间为5小时,最佳硅铝摩尔比为1∶8～1∶9;在含油污水中最佳投药量为80mg/L。还考察了PASC(80mg/L)与少量(1mg/L)有机高分子絮凝剂(阴、阳、非离子PAM及一种阳离共聚物PUPE)复配物的絮凝效果,加入PUPE使上清液透光率由单用PASC时的93.0%升到94.6%,浊度由9NTU降到7NTU。图3表3参5。

The conditions of preparing polyaluminum silicate chloride (PASC) as flocculant from sodium metasilicate, surfuric acid and a polyaluminum chloride are established experimentally on the basis of data of flocculating efficiency in purifying an oilfield produced water from Changqing (turbidity and light transmittance of precipitated water, relative quantity and precipitation speed of floccule): volume ratio of 30% Na_2SiO_3 and 30% H_2SO_4 solutions 1∶2; optimal silicilic acid polymerization (gelation) time 5 hrs; optimal molar ratio Si to Al 1∶8—1∶9; and optimal dosage in treating the produced water 80 mg/L. The flocculating efficiency of PASC at 80 mg/L with a small amount of an organic polymeric flocculant (anionic, cationic, and nonionic polyacrylamides and a cationic copolymer PUPE) in combination is also investigated: introducing additionally PUPE increases light transmittance from 93.0% for single PASC to 94.6% and decreases turbidity from 9 NTU to 7 NTU.