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
A black weathering mud containing rare earth in Southwest China contains about 3%～7% RE 2O 3. RE in the weathering mud mainly exists on the amorphous Mn Fe oxide, which can not be enriched by physical beneficiatio...A black weathering mud containing rare earth in Southwest China contains about 3%～7% RE 2O 3. RE in the weathering mud mainly exists on the amorphous Mn Fe oxide, which can not be enriched by physical beneficiation methods such as floatation, magnetic and electrostatic separation or gravity concentration etc , and can not also be exchanged by salts. Chlorinating roasting is selected to treat the black weathering mud based on the thermodynamic analysis and the properties of mud in the paper. The chlorinating roasting treatment is divided two stages. The first step is to heat the mud mixed NH 4Cl and carbon with (1.5～2.5)∶10 of NH 4Cl/mud ratio at 200℃ for 1 h. NH 4Cl directly chlorinates the RE 2O 3 in the weathering mud, but do not destroy Mn Fe amorphous structure. The secondary stage is to heat the mixture to above 350℃, NH 4Cl decomposes to NH 3 and HCl, and carbon in the mixture also takes part in chlorinating of RE. Recovery of RE reaches to 91.6% under the conditions of temperature 450℃ and roasting for 2 h, and Pb and Mn can be further recovered at the same time.展开更多
The affecting factors of leaching rate such as reacting temperature, mud particle size and concentration of reagents were determined by studying the leaching kinetics of rare earth from black weathering mud. The appar...The affecting factors of leaching rate such as reacting temperature, mud particle size and concentration of reagents were determined by studying the leaching kinetics of rare earth from black weathering mud. The apparent activation energy is 9.08 kJ/mol from calculating the experimental data. The results show that the leaching process can be described by the shrinking core model and the leaching rate is controlled by diffusion of reacting reagents and reaction product in the porous solid layer. The leaching kinetics is established as: K =7.50×10 -5 ×exp(-9 080/ RT )/ r 2 0.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A black weathering mud containing rare earth in Southwest China contains about 3%～7% RE 2O 3. RE in the weathering mud mainly exists on the amorphous Mn Fe oxide, which can not be enriched by physical beneficiation methods such as floatation, magnetic and electrostatic separation or gravity concentration etc , and can not also be exchanged by salts. Chlorinating roasting is selected to treat the black weathering mud based on the thermodynamic analysis and the properties of mud in the paper. The chlorinating roasting treatment is divided two stages. The first step is to heat the mud mixed NH 4Cl and carbon with (1.5～2.5)∶10 of NH 4Cl/mud ratio at 200℃ for 1 h. NH 4Cl directly chlorinates the RE 2O 3 in the weathering mud, but do not destroy Mn Fe amorphous structure. The secondary stage is to heat the mixture to above 350℃, NH 4Cl decomposes to NH 3 and HCl, and carbon in the mixture also takes part in chlorinating of RE. Recovery of RE reaches to 91.6% under the conditions of temperature 450℃ and roasting for 2 h, and Pb and Mn can be further recovered at the same time.
文摘The affecting factors of leaching rate such as reacting temperature, mud particle size and concentration of reagents were determined by studying the leaching kinetics of rare earth from black weathering mud. The apparent activation energy is 9.08 kJ/mol from calculating the experimental data. The results show that the leaching process can be described by the shrinking core model and the leaching rate is controlled by diffusion of reacting reagents and reaction product in the porous solid layer. The leaching kinetics is established as: K =7.50×10 -5 ×exp(-9 080/ RT )/ r 2 0.
