提高钛白粉生产中污泥滤饼固含量的研究

Study on Improving the Solid Content of Filter Cake in Titanium Dioxide Production

摘要: 钛白粉生产中酸性废水处理后产生的滤饼固含量低是行业普遍面临的工程问题。本文从中和沉淀颗粒形貌入手分析，研究了酸性废水中Fe²⁺浓度以及返浆操作对滤饼固含量的影响，实验数据表明对固含量的提高有限。此外，还研究了APAM以及实验室自制的絮凝剂X，以及三种表面活性剂(SDBS，DTAB，FMES)对固含量以及过滤速度的影响。选取SDBS分别与10 ppm的APAM和NPAM复配，研究其复配联用对固含量以及过滤速度的影响。最后，选择10 ppm的APAM与0.75%的SDBS进行复配对污水处理车间酸性废水中和后进行调理，可将滤饼固含量由31.97%上升至37.18%；滤饼表面露出所需的时间由196 s下降至83 s，滤液COD符合国家污水综合排放二级标准。

Abstract: The low solid content of the filter cake produced by the treatment of acidic wastewater is a com-mon engineering problem in the industry of titanium dioxide. To improve the solid content of the filter cake, morphology of precipitated particles, Fe²⁺ concentration in acid waste water and the operation of returning slurry on the solid content of filter cake were analyzed. The experimental data turned out that these increases in solid content were limited. In addition, the effects of APAM, flocculent X (laboratory homemade) and three kinds of surfactants (SDBS, DTAB, FMES) on solid content and filtration rate were also studied. The influences of SDBS, with the use of APAM (10 ppm) and NPAM (10 ppm) respectively, on the solid content and the filtration rate were studied. At last, taking the neutralized acidic wastewater from wastewater treatment plant as a sample, adding 0.75% SDBS with the use of 10 ppm APAM increased the solid content from 31.97% to 37.18%, and decreased the time required to expose cake surface from 196 s to 83 s. The COD of filtrate accorded with the second grade of national wastewater discharge standards.