海洋沉积物中重金属的活性形态对于指示沉积物污染状况具有重要作用,为探寻简洁且能够有效提取重金属活性形态的浸提方法,实验研究了0.1mol/L和1mol/L盐酸的单级提取和欧共体标准局(European Community Bureau of Reference)提出的BCR...海洋沉积物中重金属的活性形态对于指示沉积物污染状况具有重要作用,为探寻简洁且能够有效提取重金属活性形态的浸提方法,实验研究了0.1mol/L和1mol/L盐酸的单级提取和欧共体标准局(European Community Bureau of Reference)提出的BCR分级提取法对胶州湾表层沉积物中重金属(Cr、Cu、Ni、Pb、Zn)和Al、Fe、Mn的浸取效果。结果显示,3种提取方法提取的金属含量呈显著正相关关系,两种浓度的稀盐酸对BCR方法中的酸可提取态和可还原态金属均具有较好浸提效果,但对可氧化态金属浸提能力相对较弱。不同提取方法的人为信号指数(ASI)计算结果表明,BCR浸取法提取结果的金属ASI值最大,表明其对沉积物中金属活性形态提取效率较高;1mol/L HCl提取结果的金属ASI值最低,可能是较高浓度强酸使沉积物较大颗粒内层中"惰性"金属被浸取出来,"增加"了金属活性组分的污染讯息信号;对沉积物中Cu、Pb和Zn而言,0.1mol/L HCl提取结果的ASI值与BCR方法接近。经过Al归一化后,0.1mol/L HCl浸提的重金属含量的空间分布与胶州湾的实际污染状况相吻合,表明0.1mol/L的HCl在一定程度上能够代替复杂的BCR浸取法,此方法可简化重金属活性形态的提取步骤,适合大范围沉积物重金属污染评价。展开更多
Ti-bearing blast furnace slag is a valuable secondary resource containing about 24 percent of TiO2.In this paper a process of leaching Ti-bearing blast furnace slag with sulfuric acid to recover TiO2,and the kinetics ...Ti-bearing blast furnace slag is a valuable secondary resource containing about 24 percent of TiO2.In this paper a process of leaching Ti-bearing blast furnace slag with sulfuric acid to recover TiO2,and the kinetics of that reaction,are described.Under laboratory conditions the rate is controlled by a chemical reaction.The leaching reaction is in accord with a shrinking unre- acted-core model.The apparent reaction order of the leaching reaction was 1.222 and the apparent activation energy was 87.01 kJ/mol.The model fits the observed data well until 90%of the TiO2 has be leached from the particles.The model disagrees with observations during later periods of the reaction because the solution becomes supersaturated with Ti ions,which precipitate as H2TiO4.The assumptions of constant reactant concentration and that there is no effect from the product layer on diffusion,also cause the model to deviate from the actual values.展开更多
The modelling and optimization for the alkaline sulphide leaching of a complex copper concentrate containing 1.69% Sb and 0.14% Sn were studied.Response surface methodology,in combination with central composite face-c...The modelling and optimization for the alkaline sulphide leaching of a complex copper concentrate containing 1.69% Sb and 0.14% Sn were studied.Response surface methodology,in combination with central composite face-centred design（RSM-CCF）,was used to optimise the operating parameters.The leaching temperature,sulphide ion concentration and solid concentration were chosen as the variables,and the response parameters were antimony and tin recovery,and the time required to achieve 90% Sb dissolution.It was confirmed that the leaching process was strongly dependent on the reaction temperature as well as the sulphide ion concentration without any significant dependence on the solid concentration.Furthermore,a mathematical model was constructed to characterise the leaching behaviour.The results from the model allow identification of the most favourable leaching conditions.The model was validated experimentally,and the results show that the model is reliable and accurate in predicting the leaching process.展开更多
文摘海洋沉积物中重金属的活性形态对于指示沉积物污染状况具有重要作用,为探寻简洁且能够有效提取重金属活性形态的浸提方法,实验研究了0.1mol/L和1mol/L盐酸的单级提取和欧共体标准局(European Community Bureau of Reference)提出的BCR分级提取法对胶州湾表层沉积物中重金属(Cr、Cu、Ni、Pb、Zn)和Al、Fe、Mn的浸取效果。结果显示,3种提取方法提取的金属含量呈显著正相关关系,两种浓度的稀盐酸对BCR方法中的酸可提取态和可还原态金属均具有较好浸提效果,但对可氧化态金属浸提能力相对较弱。不同提取方法的人为信号指数(ASI)计算结果表明,BCR浸取法提取结果的金属ASI值最大,表明其对沉积物中金属活性形态提取效率较高;1mol/L HCl提取结果的金属ASI值最低,可能是较高浓度强酸使沉积物较大颗粒内层中"惰性"金属被浸取出来,"增加"了金属活性组分的污染讯息信号;对沉积物中Cu、Pb和Zn而言,0.1mol/L HCl提取结果的ASI值与BCR方法接近。经过Al归一化后,0.1mol/L HCl浸提的重金属含量的空间分布与胶州湾的实际污染状况相吻合,表明0.1mol/L的HCl在一定程度上能够代替复杂的BCR浸取法,此方法可简化重金属活性形态的提取步骤,适合大范围沉积物重金属污染评价。
基金Project 50234040 supported by the National Natural Science Foundation of China
文摘Ti-bearing blast furnace slag is a valuable secondary resource containing about 24 percent of TiO2.In this paper a process of leaching Ti-bearing blast furnace slag with sulfuric acid to recover TiO2,and the kinetics of that reaction,are described.Under laboratory conditions the rate is controlled by a chemical reaction.The leaching reaction is in accord with a shrinking unre- acted-core model.The apparent reaction order of the leaching reaction was 1.222 and the apparent activation energy was 87.01 kJ/mol.The model fits the observed data well until 90%of the TiO2 has be leached from the particles.The model disagrees with observations during later periods of the reaction because the solution becomes supersaturated with Ti ions,which precipitate as H2TiO4.The assumptions of constant reactant concentration and that there is no effect from the product layer on diffusion,also cause the model to deviate from the actual values.
文摘The modelling and optimization for the alkaline sulphide leaching of a complex copper concentrate containing 1.69% Sb and 0.14% Sn were studied.Response surface methodology,in combination with central composite face-centred design（RSM-CCF）,was used to optimise the operating parameters.The leaching temperature,sulphide ion concentration and solid concentration were chosen as the variables,and the response parameters were antimony and tin recovery,and the time required to achieve 90% Sb dissolution.It was confirmed that the leaching process was strongly dependent on the reaction temperature as well as the sulphide ion concentration without any significant dependence on the solid concentration.Furthermore,a mathematical model was constructed to characterise the leaching behaviour.The results from the model allow identification of the most favourable leaching conditions.The model was validated experimentally,and the results show that the model is reliable and accurate in predicting the leaching process.
