Fly ash was used to prepare alumina and silica white, The 3 stages of the process are as follows: ammonium sulfate calcining, acid leaching and alkali dissolution. The optimum conditions for the experiments to determi...Fly ash was used to prepare alumina and silica white, The 3 stages of the process are as follows: ammonium sulfate calcining, acid leaching and alkali dissolution. The optimum conditions for the experiments to determine are as follows: molar ratio of (NH4)2SO4/Al2O3 is 6, the calcining time is 2h, he H2SO4 concentration is 20%, the leaching temperature is 80℃ and dissolution duration is 2h, the ratio of solution and solid reaction material is 6 for ammonium sulfate calcining and acid leaching stage, reaction time 30min, ratio of liquid to ore 5∶1, alkali concentration 45% and reaction temperature 95 ℃for the alkali dissolution stage. Under these conditions, the total leaching efficiencies of Al2O3 and SiO2 are 78.86% and 95%, respectively. The quality of the main products alumina and silica white can meet the national standards of GB/T24487-2009 and GB10517-89, respectively.展开更多
Silica white was prepared with the method of molten NaOH-carbonation decomposition from the laterite nickel ore,and the content of NiO in the residue reached 2.71%.The results showed that the extraction ratio of SiO2 ...Silica white was prepared with the method of molten NaOH-carbonation decomposition from the laterite nickel ore,and the content of NiO in the residue reached 2.71%.The results showed that the extraction ratio of SiO2 increased with increasing reaction time and mass ratio of alkali to ore,and with decreasing particle size of the laterite nickel ore.Furthermore,the extraction ratio of SiO2 increased firstly and then decreased with increasing reaction temperature.XRD analysis indicated that the product was amorphous.FT-IR analysis indicated that the product was hydrated silicon dioxide.SEM morphology showed that the product was of uniform particle size with average particle size about 100 nm.The physical and chemical properties of the product conformed with the national standards of chemical industry.展开更多
文摘Fly ash was used to prepare alumina and silica white, The 3 stages of the process are as follows: ammonium sulfate calcining, acid leaching and alkali dissolution. The optimum conditions for the experiments to determine are as follows: molar ratio of (NH4)2SO4/Al2O3 is 6, the calcining time is 2h, he H2SO4 concentration is 20%, the leaching temperature is 80℃ and dissolution duration is 2h, the ratio of solution and solid reaction material is 6 for ammonium sulfate calcining and acid leaching stage, reaction time 30min, ratio of liquid to ore 5∶1, alkali concentration 45% and reaction temperature 95 ℃for the alkali dissolution stage. Under these conditions, the total leaching efficiencies of Al2O3 and SiO2 are 78.86% and 95%, respectively. The quality of the main products alumina and silica white can meet the national standards of GB/T24487-2009 and GB10517-89, respectively.
文摘Silica white was prepared with the method of molten NaOH-carbonation decomposition from the laterite nickel ore,and the content of NiO in the residue reached 2.71%.The results showed that the extraction ratio of SiO2 increased with increasing reaction time and mass ratio of alkali to ore,and with decreasing particle size of the laterite nickel ore.Furthermore,the extraction ratio of SiO2 increased firstly and then decreased with increasing reaction temperature.XRD analysis indicated that the product was amorphous.FT-IR analysis indicated that the product was hydrated silicon dioxide.SEM morphology showed that the product was of uniform particle size with average particle size about 100 nm.The physical and chemical properties of the product conformed with the national standards of chemical industry.
