油砂洗涤水处理及回用

Treatment and reuse of oil sand washing water

采用中国石油兰州化工研究中心自主研发的反相破乳剂对油砂洗涤水进行破乳和混凝絮凝处理,对处理后的油砂洗涤水进行多次回用,分析了破乳前与混凝后水中的油、悬浮物含量和水质浊度,考察了油砂洗涤水重复使用的可行性以及洗涤效果。结果表明:经过处理的油砂洗涤水中添加20%(质量分数)新鲜水回用于油砂洗涤,当重复使用5次时,处理后油砂洗涤水中含油物、化学需氧量(COD)、浊度去除率依次大于37%,30%,98%;封闭式回用会导致洗涤水中离子(如氯离子、硫酸根离子)及电导率快速增加,影响油砂洗涤效果;在补水回用时减少回用洗涤水的碱用量,处理后油砂洗涤水中含油物、COD、浊度去除率平均值依次为92.85%,54.62%,99.84%,碱用量可减少15%;补水回用与封闭式回用时的油砂收油率均大于86%。

The reverse demulsifier independently developed by Lanzhou PetroChemical Research Center of PetroChina was used to demulsify and coagulate the oil sand washing water, and the treated oil sand washing water was reused many times. The content of oil, suspended matter and turbidity of water before demulsification and after coagulation were analyzed.The feasibility and washing effect of the reuse of oil sand washing water were investigated. The results showed that when 20% fresh water was added into the treated oil sand washing water to be reused for oil sand washing for 5 times, the removal rates of oil content, COD and turbidity in the treated oil sand washing water were higher than 37%, 30% and 98% respectively.Closed recycling would lead to rapid increase of ions(such as chloride ion, sulfate ion) and conductivity in washing water, which would affect the washing effect of oil sand.When reducing alkali addition in reuse washing water in fresh water makeup, the average removal rates of oil content, COD and turbidity in the treated oil sand washing water were 92.85%, 54.62%, 99.84% in turn,and the alkali usage reduction could reach 15%. In two ways,the oil recovery was kept above 86%.