Citric acid was used to selectively extract cobalt from limonite-type laterite ores in the presence of ammonium bifluoride.The results show that ammonium bifluoride enhances the leaching of cobalt by citric acid,and 8...Citric acid was used to selectively extract cobalt from limonite-type laterite ores in the presence of ammonium bifluoride.The results show that ammonium bifluoride enhances the leaching of cobalt by citric acid,and 84.5% cobalt is extracted from a laterite ore containing 0.13% Co when leached at ambient temperature for 2 h with 30 g/L citric acid and 10 g/L ammonium bifluoride.Pyrolusite is reduced by citric acid during leaching,cobalt intergrown with which is liberated and subsequently chelated by the citric acid.The extraction of cobalt is enhanced in the presence of ammonium bifluoride because the matrix of silicate minerals is destroyed by ammonium bifluoride and the adsorbed cobalt is subsequently liberated.展开更多
A number of ion-exchange resins were tested on their capacity to adeorb citric acid,among them resin 335, D315, Amberlite IRA-35 andIRA-68 exhibited higher adsorptioncapacity We Chose resin 335 and D315 to be used for...A number of ion-exchange resins were tested on their capacity to adeorb citric acid,among them resin 335, D315, Amberlite IRA-35 andIRA-68 exhibited higher adsorptioncapacity We Chose resin 335 and D315 to be used for extraction of citric acid fromfermentation broth, followed by elution with 10% ammonia liquor decoloration with K-15 carbon and removal of ammonia with resin 732, converting citrate to free citric acidwith a concentration of 10% and on amount of readily carbonizable substance meetingthe GB 8269-87 standard.展开更多
基金Project(50725416) supported by the National Natural Science Foundation of China for Distinguished Young Scholars
文摘Citric acid was used to selectively extract cobalt from limonite-type laterite ores in the presence of ammonium bifluoride.The results show that ammonium bifluoride enhances the leaching of cobalt by citric acid,and 84.5% cobalt is extracted from a laterite ore containing 0.13% Co when leached at ambient temperature for 2 h with 30 g/L citric acid and 10 g/L ammonium bifluoride.Pyrolusite is reduced by citric acid during leaching,cobalt intergrown with which is liberated and subsequently chelated by the citric acid.The extraction of cobalt is enhanced in the presence of ammonium bifluoride because the matrix of silicate minerals is destroyed by ammonium bifluoride and the adsorbed cobalt is subsequently liberated.
文摘A number of ion-exchange resins were tested on their capacity to adeorb citric acid,among them resin 335, D315, Amberlite IRA-35 andIRA-68 exhibited higher adsorptioncapacity We Chose resin 335 and D315 to be used for extraction of citric acid fromfermentation broth, followed by elution with 10% ammonia liquor decoloration with K-15 carbon and removal of ammonia with resin 732, converting citrate to free citric acidwith a concentration of 10% and on amount of readily carbonizable substance meetingthe GB 8269-87 standard.
