摘要
With the production of crude steel, China produces several million tons of sintering dusts which contain a great deal of valuable metals such as, K, Na, Zn, Pb. If discharged directly without adequate treatment, these elements can lead to adverse effects on the environment. Therefore, it is very necessary to determine how to separate these elements from the dust before discharge, Several physical and chemical detection methods were used to study the basic properties of sintering dust. At the same time, preliminary experiments on the recovery of the potassium resources from the sintering dust were carried out. The mean particle size of the electrostatic precipitator （ESP） dust determined by a laser granulometer was 41.468 ~tm. Multi-point BET and single-point BET analysis showed that the surface area of the ESP dust was 2.697 mZ/g. XRD measurements detected the following phases in the ESP dust： Fe203, Fe304, KC1 and NaC1, and Fe203, Fe304 and SiO2 in the water-washed dust. SEM-EDS results proved that in the ESP dust, K mostly existed in the form of KC1 particles without being coated. Leaching experiments showed that the KCI in the ESP dust could be separated and recovered by water leaching and fractional crystallization. Through the recovery experiments, the yield of K-Na vaporized crystalline salt was 18.56%, in which the mass fractions of KCl, NaCl, CaSO4 and K2SO4 were about 61.03%, 13.58%, 14.03% and 9.97%, respectively. This process is technically viable and considerable in economic benefit. There was almost no secondary pollution produced in the whole recovery process.
With the production of crude steel, China produces several million tons of sintering dusts which contain a great deal of valuable metals such as, K, Na, Zn, Pb. If discharged directly without adequate treatment, these elements can lead to adverse effects on the environment. Therefore, it is very necessary to determine how to separate these elements from the dust before discharge, Several physical and chemical detection methods were used to study the basic properties of sintering dust. At the same time, preliminary experiments on the recovery of the potassium resources from the sintering dust were carried out. The mean particle size of the electrostatic precipitator （ESP） dust determined by a laser granulometer was 41.468 ~tm. Multi-point BET and single-point BET analysis showed that the surface area of the ESP dust was 2.697 mZ/g. XRD measurements detected the following phases in the ESP dust： Fe203, Fe304, KC1 and NaC1, and Fe203, Fe304 and SiO2 in the water-washed dust. SEM-EDS results proved that in the ESP dust, K mostly existed in the form of KC1 particles without being coated. Leaching experiments showed that the KCI in the ESP dust could be separated and recovered by water leaching and fractional crystallization. Through the recovery experiments, the yield of K-Na vaporized crystalline salt was 18.56%, in which the mass fractions of KCl, NaCl, CaSO4 and K2SO4 were about 61.03%, 13.58%, 14.03% and 9.97%, respectively. This process is technically viable and considerable in economic benefit. There was almost no secondary pollution produced in the whole recovery process.
基金
supported by the National High Technology Research and Development Program of China (863 Program) (No. 2012AA062502)
the National Natural Science Foundation of China (No. 50974018)
