摘要
高岭土尾矿中含有铝、铁,可用来制备新型无机高分子絮凝剂聚合氯化铝铁(PAFC)。制备聚合氯化铝铁的工艺分煅烧、酸浸、水解聚合调整3个阶段。采用正交试验和单因素变量法考察了影响铝、铁溶出率的各种因素。结果表明,铝、铁溶出的最佳条件为:煅烧温度650℃,煅烧时间2 h,酸浸温度85℃,酸浸时间2 h,酸浸质量分数15%,固液比1∶3。在此条件下铝、铁的溶出率达到89%。铝、铁水解聚合的最佳工艺条件为:熟化温度55℃,熟化时间10 h,水解聚合调整阶段加氧化钙2.0 g/100 mL。在此条件下制备的混凝剂聚合氯化铝铁稳定性好,含铝6.94%,应用于实际的造纸污水处理,可使CODCr由18 000 mg/L降为400 mg/L,去除率达97.8%,净水效果明显。
The paper is concerned about the condition for preparing poly-aluminum ferric chloride （PAFC） with kaolin tailings in Suzhou. As is known, kaolin tailings can be used for preparing a new inorgan- ic high polymer coagulant known as poly aluminum ferric chloride（PAFC） for it contains aluminum and iron. But since the aluminum- silicon content in kaolin railings exists in a form of intricate crystal, which is a compound hardly soluble in acidic solution, it is necessary to sinter the fly ash to break up the bonds of SiO2-AI203 so as to make it easy to heighten its solubility in the acid. Moreover, when prepar- ing the polymeric aluminum ferric chloride from the kaolin railings, it is possible for us to use three processing methods, including high temperature calcinations, acid leading and hydrolysis polymerization. Furthermore, in order to improve the preparation efficiency of the polymeric aluminum ferric chloride, we have investigated various fac- tors that may influence the aluminum and iron dissolution rate in acid by using the orthogonal experiment and single factor variable method. The best results obtained from our experiments can be stated as fol- lows： The best dissolving condition for ferric and aluminum can be found in the recycling use of kaolin tailings, that is, at the roasting temperature of 650 ℃, during the roasting time of 2 h, at the acid picking temperature of 85%, during the acid picking reaction time of 2 h, with the mass fraction of hydrochloric acid as the rate of 15% and the mass ration of soiled-liquid of 1：3. It is on all the above mentioned conditions that the total extraction rate of ferric and alu- minum oxides from kaolin can be expected to reach over 89 % . The optimal hydrolytic-polymerizing condition can also be obtained by us- ing calcium oxide as alkalinizing agent, that is, under the hydrolytic- polymerizing reaction temperature of 55 ℃, during the hydrolytic- polymerizing reaction time of 10 h, with 2.0 g/100 mL of calcium oxide being added during the hydrolytic polymerization adjustment pe- riod. Under the above conditions, the polymeric aluminum ferric chloride （PAFC） can be obtained with nice stability of composite in- organic polymer coagulant and the aluminum content in the polymeric aluminum ferric chloride expected to reach 6.94%. At the same time, the polymeric aluminum ferric chloride can also be used for pu- rifying papermaking sewage, whose removing rate can be expected to reach 97.8% by reducing CODcr from 18 000 mg/L to 400 mg/L. Needless to say, the results that we have gained proves to be optimal and satisfactory.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2013年第5期52-55,共4页
Journal of Safety and Environment
基金
国家自然科学基金项目(51103120)
苏州科技学院研究生创新项目(SKCX12S-044)
