In order to relieve the equipment corrosion,reduce chlorine and increase phosphorus contents in leaching solution,theleaching behavior of potassium from phosphorus-potassium associated ore in the mixed acids of hydroc...In order to relieve the equipment corrosion,reduce chlorine and increase phosphorus contents in leaching solution,theleaching behavior of potassium from phosphorus-potassium associated ore in the mixed acids of hydrochloric acid and phosphoricacid was investigated.The effects of various factors,such as mass fraction of hydrochloric acid,solid-to-liquid ratio,material ratio(CaF2dosage(g)/mass of ore(g))and leaching temperature were comprehensively studied.It was found that the dissolution fractionof potassium can reach more than86%under the optimum conditions of leaching temperature95°C,HCl concentration10%,leaching time6h,solid/liquid ratio1:5,and material ratio0.1.In addition,the leaching kinetics of potassium was successfullymodeled by a semi-empirical kinetic model based on the classic shrinking core model.The data showed that the leaching process ofpotassium was controlled by the product layer diffusion and the apparent activation energy for the process was found to be54.67kJ/mol over the temperature range from65to95°C.展开更多
Potassium and phosphate were extracted at low temperature by acid hydrolysis process to decompose a new type of associated phosphorus and potassium ore. The main factors affecting the dissolution rate were investigate...Potassium and phosphate were extracted at low temperature by acid hydrolysis process to decompose a new type of associated phosphorus and potassium ore. The main factors affecting the dissolution rate were investigated, such as grinding fineness, the amount of sulfuric acid and fluoride salt, reaction time and temperature, etc. Meanwhile, the effects of various factors on the formation of soluble potassium and phosphate were also discussed. The reaction products and residues were determined by X-ray diffraction（XRD）, scanning electron microscopic（SEM） analysis and other means. The results showed that the dissolution rates of potassium and phosphorus were 70wt% and 93.7wt%, respectively, under the conditions of a grain size of 95.64wt% lessthan 0.074 mm, 9.78 g·g^（-1） sulfuric acid, 0.5 g·g^（-1） ammonium fluoride, 160 ℃ and a reaction time of 2h. The thermodynamic and chemical reaction mechanism was revealed that the primary reaction could be completed spontaneously in a temperature range of 298-433 K. The increase of reaction temperature had an important influence on ion exchange reaction, which was more conducive to the spontaneous process. The research will open up a new way for efficient use of potassium ore resources.展开更多
基金Project(51274153) supported by the National Natural Science Foundation of ChinaProjects(2011CDA120,2015CFB523) supported by the Natural Science Foundation of Hubei Province of China+2 种基金Project(G201510) supported by the State Key Laboratory of Refractories and Metallurgy(Wuhan University of Science and Technology)ChinaProject(K201454) supported by the Youths Science Foundation of Wuhan Institute of Technology,China
文摘In order to relieve the equipment corrosion,reduce chlorine and increase phosphorus contents in leaching solution,theleaching behavior of potassium from phosphorus-potassium associated ore in the mixed acids of hydrochloric acid and phosphoricacid was investigated.The effects of various factors,such as mass fraction of hydrochloric acid,solid-to-liquid ratio,material ratio(CaF2dosage(g)/mass of ore(g))and leaching temperature were comprehensively studied.It was found that the dissolution fractionof potassium can reach more than86%under the optimum conditions of leaching temperature95°C,HCl concentration10%,leaching time6h,solid/liquid ratio1:5,and material ratio0.1.In addition,the leaching kinetics of potassium was successfullymodeled by a semi-empirical kinetic model based on the classic shrinking core model.The data showed that the leaching process ofpotassium was controlled by the product layer diffusion and the apparent activation energy for the process was found to be54.67kJ/mol over the temperature range from65to95°C.
基金Funded by the National Natural Science Fundation of China(51274158)the National Twelfth Five-Year Plan for Scientific and Technological Support(2013BAE04B03)the Scientific and Technological Support Project of Hubei Province(2015BCA251)
文摘Potassium and phosphate were extracted at low temperature by acid hydrolysis process to decompose a new type of associated phosphorus and potassium ore. The main factors affecting the dissolution rate were investigated, such as grinding fineness, the amount of sulfuric acid and fluoride salt, reaction time and temperature, etc. Meanwhile, the effects of various factors on the formation of soluble potassium and phosphate were also discussed. The reaction products and residues were determined by X-ray diffraction（XRD）, scanning electron microscopic（SEM） analysis and other means. The results showed that the dissolution rates of potassium and phosphorus were 70wt% and 93.7wt%, respectively, under the conditions of a grain size of 95.64wt% lessthan 0.074 mm, 9.78 g·g^（-1） sulfuric acid, 0.5 g·g^（-1） ammonium fluoride, 160 ℃ and a reaction time of 2h. The thermodynamic and chemical reaction mechanism was revealed that the primary reaction could be completed spontaneously in a temperature range of 298-433 K. The increase of reaction temperature had an important influence on ion exchange reaction, which was more conducive to the spontaneous process. The research will open up a new way for efficient use of potassium ore resources.
