To extract vanadium in an environment friendly manner, this study focuses on the process of leaching vanadium from vanadium slag by high pressure oxidative acid leaching. Characterizations of the raw slag, mineralogy ...To extract vanadium in an environment friendly manner, this study focuses on the process of leaching vanadium from vanadium slag by high pressure oxidative acid leaching. Characterizations of the raw slag, mineralogy transformation, and the form of leach residues were made by X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The result shows that the vana-dium slag is composed of major phases of fayalite, titanomagnetite, and spinel. During the high pressure oxidative acid leaching process, the fayalite and spinel phases are gradually decomposed by sulfuric acid, causing the release of vanadium and iron in the solution. Meanwhile, unreacted silicon and titanium are enriched in the leach residues. With the initial concentration of sulfuric acid at 250 g·L^-1, a leaching tem-perature of 140℃, a leaching time of 50 min, a liquid-solid ratio of 10：1 mL·g^-1, and oxygen pressure at 0.2 MPa, the leaching rate of vana-dium reaches 97.69%.展开更多
The technology of in situ immobilization with amendments is an important measure that remediates the soil contaminated by heavy metals, and selecting economical and effective amendments is the key. The effects and mec...The technology of in situ immobilization with amendments is an important measure that remediates the soil contaminated by heavy metals, and selecting economical and effective amendments is the key. The effects and mechanism of steel slag, the silicon-rich alkaline byproduct which can remediate acidic soil contaminated by heavy metal, are mainly introduced in this paper to provide theory reference for future research. Firstly, the paper analyzes current research situation of in situ immobilization with amendments. Then, it introduces the main physicochemical properties of steel slag, and the effect on soil pH value as well as heavy metal activity. Besides, the paper elaborates the promoting effect on silicon-requiring plant and the strengthening mechanism for its resistant capability of heavy metal. According to the analysis, the application of steel slag could be a potential valuable strategy to remediate acidic soil contaminated by heavy metal by modifying the transformation of heavy metals in both soil and plant, so that the translocation of heavy metal in food chain is reduced.展开更多
A two-step leaching method in combination of acid and ethylene diaminetetraacetic acid disodium (EDTA-Na2) was applied to extract metals such as Cd,Cu,Fe,Pb and Zn from a zinc smelting slag. The results show that the ...A two-step leaching method in combination of acid and ethylene diaminetetraacetic acid disodium (EDTA-Na2) was applied to extract metals such as Cd,Cu,Fe,Pb and Zn from a zinc smelting slag. The results show that the extraction rates of Cd,Cu,Fe and Zn in slag reach 88.3%,54.1%,69.6% and 54.7%,respectively,while the extraction rate of Pb is only 0.05% leached with 1.25 mol/L sulfuric acid under the conditions of the ratio of slag to liquid of 100 g/L,65 °C and 120 r/min for 2 h. However,Pb extraction rate from 1.25 mol/L sulfuric acid leached residue reaches as high as 66.5% by using 0.1 mol/L EDTA-Na2 solution. The results indicate that two-step sequential extraction procedure combining 1.25 mol/L sulfuric acid and 0.1 mol/L EDTA-Na2 solution can extensively extract Cd,Cu,Fe,Pb and Zn from zinc smelting slag.展开更多
A new process of cryolite preparation is studied in this work by selecting a proper system of reaction and weeding impurity technology. The quality of artifial cryolite reaches and exceeds the first level of national ...A new process of cryolite preparation is studied in this work by selecting a proper system of reaction and weeding impurity technology. The quality of artifial cryolite reaches and exceeds the first level of national standard. The utilization efficient of fluoride-containing acid slag is above 99.5%. It brings considerable economic benefit, and the environment is improved.展开更多
基金supported by the National High Technology Research and Development Program of China(No.2012AA062303)the National Natural Science Foundation of China(Nos.U1202274,51004033,and 51204040)the Doctoral Fund Project of China(No. 20120042110011)
文摘To extract vanadium in an environment friendly manner, this study focuses on the process of leaching vanadium from vanadium slag by high pressure oxidative acid leaching. Characterizations of the raw slag, mineralogy transformation, and the form of leach residues were made by X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The result shows that the vana-dium slag is composed of major phases of fayalite, titanomagnetite, and spinel. During the high pressure oxidative acid leaching process, the fayalite and spinel phases are gradually decomposed by sulfuric acid, causing the release of vanadium and iron in the solution. Meanwhile, unreacted silicon and titanium are enriched in the leach residues. With the initial concentration of sulfuric acid at 250 g·L^-1, a leaching tem-perature of 140℃, a leaching time of 50 min, a liquid-solid ratio of 10：1 mL·g^-1, and oxygen pressure at 0.2 MPa, the leaching rate of vana-dium reaches 97.69%.
文摘The technology of in situ immobilization with amendments is an important measure that remediates the soil contaminated by heavy metals, and selecting economical and effective amendments is the key. The effects and mechanism of steel slag, the silicon-rich alkaline byproduct which can remediate acidic soil contaminated by heavy metal, are mainly introduced in this paper to provide theory reference for future research. Firstly, the paper analyzes current research situation of in situ immobilization with amendments. Then, it introduces the main physicochemical properties of steel slag, and the effect on soil pH value as well as heavy metal activity. Besides, the paper elaborates the promoting effect on silicon-requiring plant and the strengthening mechanism for its resistant capability of heavy metal. According to the analysis, the application of steel slag could be a potential valuable strategy to remediate acidic soil contaminated by heavy metal by modifying the transformation of heavy metals in both soil and plant, so that the translocation of heavy metal in food chain is reduced.
基金Project(2011SK3262) supported by Science and Technology Program of Hunan Province,China
文摘A two-step leaching method in combination of acid and ethylene diaminetetraacetic acid disodium (EDTA-Na2) was applied to extract metals such as Cd,Cu,Fe,Pb and Zn from a zinc smelting slag. The results show that the extraction rates of Cd,Cu,Fe and Zn in slag reach 88.3%,54.1%,69.6% and 54.7%,respectively,while the extraction rate of Pb is only 0.05% leached with 1.25 mol/L sulfuric acid under the conditions of the ratio of slag to liquid of 100 g/L,65 °C and 120 r/min for 2 h. However,Pb extraction rate from 1.25 mol/L sulfuric acid leached residue reaches as high as 66.5% by using 0.1 mol/L EDTA-Na2 solution. The results indicate that two-step sequential extraction procedure combining 1.25 mol/L sulfuric acid and 0.1 mol/L EDTA-Na2 solution can extensively extract Cd,Cu,Fe,Pb and Zn from zinc smelting slag.
文摘A new process of cryolite preparation is studied in this work by selecting a proper system of reaction and weeding impurity technology. The quality of artifial cryolite reaches and exceeds the first level of national standard. The utilization efficient of fluoride-containing acid slag is above 99.5%. It brings considerable economic benefit, and the environment is improved.
