全尾砂絮凝沉降规律及其机理

第32卷第6期2010年6月北京科技大学学报JournalofUniversityofScienceandTechnologyBeijingVo.l32No.6Jun.2010全尾砂絮凝沉降规律及其机理焦华喆1)�王洪江1)�吴爱祥1)�吉学文2)�严庆文2)�李�祥2)1)北京科技大学土木与环境工程学院,北京100083�2)云南驰宏锌锗股份有限公司,曲靖654211摘�要�以某矿全尾砂和聚丙烯酰胺(PAM)为实验原料进行静态絮凝沉降实验,研究给料浓度和絮凝剂单耗对尾矿最大沉降速度和静止沉降极限浓度的影响,通过对实验数据回归分析得出简易的沉降速度模型.将模型划分为六个阶段,包括紊流影响段、加速沉降段、沉降末速段、干涉沉降区、压密沉降段和极限沉降段,并利用两相流理论、絮凝理论对其合理性进行阐述.实验结果证明:在单耗一定(20g�t-1)时,沉降速度与给料浓度负相关,极限浓度与给料浓度正相关;在给料质量分数20%时,单耗临界值为30g�t-1,极限浓度与单耗负相关.建议深锥浓密机给料质量分数20%,絮凝剂单耗20g�t-1.关键词�尾砂;絮凝沉降;固液分离;速度模型分类号�TD926�2RuleandmechanismofflocculationsedimentationofunclassifiedtailingsJIAOHua�zhe1),WANGHong�jiang1),WUAi�xiang1),JIXue�wen2),YANQing�wen2),LIXiang2)1)SchoolofCivilandEnvironmentalEngineering,UniversityofScienceandTechnologyBeijing,Beijing100083,China2)YunnanChihongZn&GeCo.Ltd.,Qujing654211,ChinaABSTRACT�Staticflocculationandsedimentationexperimentswithpolyacrylamideandunclassifiedtailingsfromaminewerecom�pletedtostudytheeffectsoffeedingconcentrationandflocculantsunitconsumptiononthemaximumsedimentationvelocityandlimitconcentrationoftailingsunderstaticsedimentation.Asimplemodelofsedimentationvelocitywasestablishedthroughregressionanaly�sisonexperimentaldata.Themodelwasdividedintosixphasesincludingturbulentflowaffectedsegment,acceleratingsedimentationsegment,terminalvelocitysegment,interferencesedimentationsegment,dewateringsedimentationsegment,andlimitsedimentationsegment.Therationalityofthemodelwasexplainedbythetwo�phaseflowtheoryandtheflocculationtheory.Theresultsshowthatatacertainunitconsumptionofflocculants(20g�t-1),thesedimentationvelocityisnegativelycorrelatedandthelimitconcentrationispositivelycorrelatedtothefeedingconcentration.Atthefeedingconcentrationof20%,thecriticalvalueofunitconsumptionis30g�t-1,andthelimitconcentrationisnegativelycorrelatedtotheunitconsumption.Aprojectwasproposedthatthefeedingconcentrationis20%andtheunitconsumptionofflocculantsis20g�t-1.KEYWORDS�tailings;flocculationsedimentation;solid�liquidseparation;velocitymodel收稿日期:2009��07��06基金项目:!十一五∀国家科技支撑计划