CaCl_2-PAC絮凝法处理含氟废水的研究

文章绘制了水溶液中总氟与游离钙离子和pH值的关系图,并结合氯化钙、PAC混凝剂处理含氟废水,分别考察了氯化钙的加入量和PAC加入量对除氟的影响。结果表明,在氯化钙加入量为100 mg/L时,水样中氟离子残余量为10.2 mg/L,在溶液pH值为6.5,PAC加入量为400 mg/L时,水样中残余氟离子浓度为3.62 mg/L。同时考察了先加入100 mg/L的氯化钙反应90 min,PAC絮凝剂加入量对除氟的影响,温度对氯化钙除氟影响不大,在55℃时PAC的絮凝效果最佳。

Leaching of low grade zinc oxide ores in Ida^(2-)-H_2O system

Ida2--H2O system（iminodiacetate aqueous solution） was used to leach a low grade zinc oxide ore for Zn extraction.The effects of leaching time,liquid-solid ratio（L/S）,total concentration of Ida2-（[Ida2-]T）,leaching temperature and pH on Zn leaching recovery and the dissolution of impurities such as Ca,Mg,Cu,Ni,Fe,Pb and Cd were investigated.Results show that Ca,Mg and Fe in ores were hardly dissolved in alkalescent iminodiacetate aqueous solution,while valuable metals such as Cu,Ni,Pb and Cd were partly dissolved into leaching liquor with Zn.The recovery of Zn reaches 76.6% when the ores were leached for 4 h at 70 ℃ by 0.9 mol/L iminodiacetate aqueous solution with pH of 8 and L/S of 5：1.

Zn^(2+)-Ida^(2-)-CO_3^(2-)-H_2O体系浸出液中锌的回收及浸出剂的再生

研究了从亚氨基二乙酸浸出低品位氧化锌矿所得的Zn2+-Ida2--H2O溶液中锌的回收和浸出剂的再生。首先加入CaO调节溶液pH使锌以粗氧化锌形式加以回收,然后通入CO2气体使沉锌过程中所积累的大量钙离子以CaCO3形式脱除,同时实现浸出剂亚氨基二乙酸的再生。确定沉锌工艺条件如下:沉锌温度85℃、终点pH值10、陈化时间60 min;沉钙工艺条件如下:沉钙温度70℃、终点pH值8、CO2流量0.2 L/min。结果表明:浸出液按上述条件进行沉锌—沉钙—再浸出处理后,沉锌率为93.37%,沉钙率为97.88%,锌浸出率为78%;所得粗氧化锌含锌56.91%、铅3.40%,碳酸钙纯度大于97%。

铅冰铜控制电位选择性氯化浸出

采用控制电位氯化浸出铅冰铜,介绍了控制电位浸出的原理和过程,并在试验的基础上,探讨了电位、[H2SO4]、[HCl]、反应温度、反应时间对铜、铅、铁、银浸出率的影响,结果表明,浸出过程中,电位、[H2SO4]、[HCl]对铜、铁、银的浸出率有较大影响,而反应温度和反应时间对整个过程影响较小,同时确定了控制电位氯化浸出铅冰铜的最佳条件为[H2SO4]=2.0 mol/L,[HCl]=2.0mol/L,L∶S=5∶1,电位400 mV,温度353K,时间2 h。在此条件下,铜、铁、铅、银的浸出率分别为98.27%、99.07%、4.21%、1.54%,实现了铜、铅、银的有效分离。