A new technology was developed to recover V2O5 from Bayer spent liquor by ion exchange.The experimental results show that in the conditions of 105℃ and 0.20-0.25 mass ratios between CaO in lime and Al2O3 in spent liq...A new technology was developed to recover V2O5 from Bayer spent liquor by ion exchange.The experimental results show that in the conditions of 105℃ and 0.20-0.25 mass ratios between CaO in lime and Al2O3 in spent liquor, the precipitation rate of vanadium in Bayer liquor is more than 85%.The vanadium-bearing precipitation is leached by NaHCO3 solution.The leaching rate of vanadium can reach 85% in the conditions of 95℃, 40 g·L-1 of NaHCO3 concentration, and ventilating of CO2.The 201 × 7 type of resin has good adsorption effect on vanadium in the leaching solution.The adsorption rate is more than 94% with the flow rate of 0.09 mL·min-1·g-1 of leaching solution and the temperature of 40-50℃.By using 3 mol·L-1 of NaOH to desorb the saturated resin after adsorption at 40-50℃, a solution with more than 5 g·L-1 of V2O5 can be obtained.After roasting ammonium metavanadate that precipitates from the desorption solution when NH4Cl is added at the temperature of 500-550℃ for 2 h, V2O5 with more than 99% of purity is obtained.展开更多
Through collecting groundwater samples from the coastal region of Tangshan, China, the hydrochemical processes that affect the chemical composition of groundwater and the quality of resources were analyzed. Chemical c...Through collecting groundwater samples from the coastal region of Tangshan, China, the hydrochemical processes that affect the chemical composition of groundwater and the quality of resources were analyzed. Chemical constituents, factor analysis, and a graphic method were employed in this research. The results show that human activities obviously affect fresh groundwater. The deep groundwater distributed in the southern part of the region is severely affected by salinization, and the shallow groundwater in the north is also beginning to show the same deterioration. The chemical concentrations of the deep groundwater depend largely upon the water-rock interaction, the mixing of saline water and the ion exchange processes. With the exception of sample C-33, all the groundwater samples in the study area are suitable for drinking. Tests show that roughly half of the deep groundwater samples have at least one water quality index indicating that it is chemically doubtful or unsuitable for irrigation. Therefore, it is concluded that deep groundwater is becoming an unacceptable resource to irrigate areas located near the coastline because the groundwater quality in the study area is exhibiting signs of degradation. This study＇s findings contribute to a better understanding of groundwater resources in order to support regional management and protection.展开更多
文摘A new technology was developed to recover V2O5 from Bayer spent liquor by ion exchange.The experimental results show that in the conditions of 105℃ and 0.20-0.25 mass ratios between CaO in lime and Al2O3 in spent liquor, the precipitation rate of vanadium in Bayer liquor is more than 85%.The vanadium-bearing precipitation is leached by NaHCO3 solution.The leaching rate of vanadium can reach 85% in the conditions of 95℃, 40 g·L-1 of NaHCO3 concentration, and ventilating of CO2.The 201 × 7 type of resin has good adsorption effect on vanadium in the leaching solution.The adsorption rate is more than 94% with the flow rate of 0.09 mL·min-1·g-1 of leaching solution and the temperature of 40-50℃.By using 3 mol·L-1 of NaOH to desorb the saturated resin after adsorption at 40-50℃, a solution with more than 5 g·L-1 of V2O5 can be obtained.After roasting ammonium metavanadate that precipitates from the desorption solution when NH4Cl is added at the temperature of 500-550℃ for 2 h, V2O5 with more than 99% of purity is obtained.
基金funded by the Special Funds for the National Basic Research Program of China (No. 2010CB428803)
文摘Through collecting groundwater samples from the coastal region of Tangshan, China, the hydrochemical processes that affect the chemical composition of groundwater and the quality of resources were analyzed. Chemical constituents, factor analysis, and a graphic method were employed in this research. The results show that human activities obviously affect fresh groundwater. The deep groundwater distributed in the southern part of the region is severely affected by salinization, and the shallow groundwater in the north is also beginning to show the same deterioration. The chemical concentrations of the deep groundwater depend largely upon the water-rock interaction, the mixing of saline water and the ion exchange processes. With the exception of sample C-33, all the groundwater samples in the study area are suitable for drinking. Tests show that roughly half of the deep groundwater samples have at least one water quality index indicating that it is chemically doubtful or unsuitable for irrigation. Therefore, it is concluded that deep groundwater is becoming an unacceptable resource to irrigate areas located near the coastline because the groundwater quality in the study area is exhibiting signs of degradation. This study＇s findings contribute to a better understanding of groundwater resources in order to support regional management and protection.
