A novel process to extract and separate rare earth (RE) and manganese (Mn) from Panxi rare earth mud was developed. The process involves roasting the mud at 480?℃ with NH 4Cl as chlorinating agent, and leaching the c...A novel process to extract and separate rare earth (RE) and manganese (Mn) from Panxi rare earth mud was developed. The process involves roasting the mud at 480?℃ with NH 4Cl as chlorinating agent, and leaching the calcine with hot water to obtain a rare earth chloride solution. After the solution was further purified, HD(DIBM)P (P 507 ) was applied as extractant to separate RE and Mn. By seven stages of fractional extraction, the RECl 3 and MnCl 2 solutions with 99.8% purity were obtained. Finally, the purified RECl 3 and MnCl 2 solution were precipitated by NH 4HCO 3 to obtain a crystal RE 2(CO 3) 3 and MnCO 3 products respectively.展开更多
The concentration and chemical speciation of heavy metals including REEs （rare earth elements）, Th （thorium） and U （uranium） in domestic sludge and electroplating sludge were investigated, and those of the domes...The concentration and chemical speciation of heavy metals including REEs （rare earth elements）, Th （thorium） and U （uranium） in domestic sludge and electroplating sludge were investigated, and those of the domestic sludge were compared with those of natural soil. Removal of heavy metals in electroplating sludge was studied with bio-surfactants （saponin and sophorolipid） by batch and column experiments. The results suggested that heavy metals have greater concentrations and exist as more relatively unstable fraction in sludge than those in Natural soil. Nonionic saponin is more efficient than sophorolipid for the removal of heavy metals from the electroplating sludge, and mainly reacts with carbonate state （i.e., F3） and Fe-Mn oxide state （i.e., F5） fractions. The recovery efficiency of heavy metals in leachates from the electroplate sludge was attained 88%-97%. Saponin can be reused and be a promising and cost-effective material for the removal of heavy metals in sludge.展开更多
文摘A novel process to extract and separate rare earth (RE) and manganese (Mn) from Panxi rare earth mud was developed. The process involves roasting the mud at 480?℃ with NH 4Cl as chlorinating agent, and leaching the calcine with hot water to obtain a rare earth chloride solution. After the solution was further purified, HD(DIBM)P (P 507 ) was applied as extractant to separate RE and Mn. By seven stages of fractional extraction, the RECl 3 and MnCl 2 solutions with 99.8% purity were obtained. Finally, the purified RECl 3 and MnCl 2 solution were precipitated by NH 4HCO 3 to obtain a crystal RE 2(CO 3) 3 and MnCO 3 products respectively.
文摘The concentration and chemical speciation of heavy metals including REEs （rare earth elements）, Th （thorium） and U （uranium） in domestic sludge and electroplating sludge were investigated, and those of the domestic sludge were compared with those of natural soil. Removal of heavy metals in electroplating sludge was studied with bio-surfactants （saponin and sophorolipid） by batch and column experiments. The results suggested that heavy metals have greater concentrations and exist as more relatively unstable fraction in sludge than those in Natural soil. Nonionic saponin is more efficient than sophorolipid for the removal of heavy metals from the electroplating sludge, and mainly reacts with carbonate state （i.e., F3） and Fe-Mn oxide state （i.e., F5） fractions. The recovery efficiency of heavy metals in leachates from the electroplate sludge was attained 88%-97%. Saponin can be reused and be a promising and cost-effective material for the removal of heavy metals in sludge.
