Pelletization is one of useful processes for the agglomeration of iron ore or concentrates. However, manganese ore fines are mainly agglomerated by sintering due to its high combined water which adversely affects the ...Pelletization is one of useful processes for the agglomeration of iron ore or concentrates. However, manganese ore fines are mainly agglomerated by sintering due to its high combined water which adversely affects the roasting performance of pellets. In this work, high pressure roll grinding(HPRG) process and optimization of temperature elevation system were investigated to improve the strength of fired manganese ore pellets. It is shown that the manganese ore possesses good ballability after being pretreated by HPRG twice, and good green balls were produced under the conditions of blending 2.0% bentonite in the feed, balling for 7 min at 16.00% moisture. High quality roasted pellets with the compressive strength of 2711 N per pellet were manufactured through preheating at 1050 °C for 10 min and firing at 1335 °C for 15 min by controlling the cracks formation. The fired manganese pellets keep the strength by the solid interconnection of recrystallized pyrolusite grains and the binding of manganite liquid phase which filled the pores and clearance among minerals. The product pellets contain high Mn grade and low impurities, and can be used to smelt ferromanganese, which provides a possible way to use imported manganese ore fines containing high combined water to produce high value ferromanganese.展开更多
The effects of magnetic field intensity, roasting temperature and roasting time on digestion rate and settling performance of bauxite with different iron contents were investigated systematically. The results indicate...The effects of magnetic field intensity, roasting temperature and roasting time on digestion rate and settling performance of bauxite with different iron contents were investigated systematically. The results indicate that such magnetic treatment can profoundly change the microstructure and digestion performance of bauxite. For the two samples carrying different iron contents, phase transformation of the aluminum oxide phase proceeds faster in the high iron bauxite than the low one. The optimal pretreatment conditions of low iron bauxite are roasting temperature 550 ℃ and magnetic field intensity 6 T, while for high iron bauxite are 500 ℃ and 9 T. The digestion rate of alumina can reach 95% and 92% at digestion temperature of 190 ℃ and 250 ℃. The settling performances of roasted ore by intense magnetic field after digestion are enhanced through pretreatment.展开更多
To control contamination of flue gas emission NOx, the author mixcd method of preparing new magnesia base catalyst and researched on denitrificating fine gas by directness catalytic decomposition. Usually removal rate...To control contamination of flue gas emission NOx, the author mixcd method of preparing new magnesia base catalyst and researched on denitrificating fine gas by directness catalytic decomposition. Usually removal rate of NO is regarded on the main evaluation criteria. The author analyzed calcination temperature of catalyzer manufacturing process, the temperature of flue gas desorption tower, bed height and efficiency denitrification of NO concentration. And discussed the result of both denitrate lore-and-aft of FT-IR and XRD. The experiment indicates that magnesia base catalyst is available to directness catalytic decomposition denitrificate flue gas. Through denitrification rate is from 85% to 95%. The ingredient of magnesia base catalyst is made from magnesia, firming agent, addition agent. Height denitration bed was 4 cm- 5 cm, deuitration reaction temperature is 130℃-170℃, through the analyses above, presumed that magnesia base catalyst exist activating of vice, and analyzed this vice preliminarily.展开更多
The CO_2 absorption ability of synthetic calcium-based sorbent modified by peanut husk ash (PHA) was tested by Thermal Gravimetric Analyzer (TGA), and the effects of steam and calcination temperature were investigate...The CO_2 absorption ability of synthetic calcium-based sorbent modified by peanut husk ash (PHA) was tested by Thermal Gravimetric Analyzer (TGA), and the effects of steam and calcination temperature were investigated. The PHA composition was analyzed by X-Ray Fluorescence (XRF), the apparent morphology was characterized by scanning electron microscope (SEM), and the phases of the sorbent before and after calcination were examined by X-ray diffraction (XRD). The addition of PHA effectively improved the cyclic stability of the calcium-based sorbent. The optimal molar ratio of SiO_2 in PHA to CaO was around 0.07. Steam had positive effect on keeping porosity of the sorbent at the chemical reaction stage, and improved its CO_2 absorption ability. Steam also reduced the diffusion resistance of the product layer, and depressed the influence of high temperature calcination. It was also found that the steam hydration after calcination was an effective way to recover the absorption ability of the sorbent, while the hydration duration of 10 min was enough.展开更多
基金Project(2011GH561685)supported by the China Torch Program
文摘Pelletization is one of useful processes for the agglomeration of iron ore or concentrates. However, manganese ore fines are mainly agglomerated by sintering due to its high combined water which adversely affects the roasting performance of pellets. In this work, high pressure roll grinding(HPRG) process and optimization of temperature elevation system were investigated to improve the strength of fired manganese ore pellets. It is shown that the manganese ore possesses good ballability after being pretreated by HPRG twice, and good green balls were produced under the conditions of blending 2.0% bentonite in the feed, balling for 7 min at 16.00% moisture. High quality roasted pellets with the compressive strength of 2711 N per pellet were manufactured through preheating at 1050 °C for 10 min and firing at 1335 °C for 15 min by controlling the cracks formation. The fired manganese pellets keep the strength by the solid interconnection of recrystallized pyrolusite grains and the binding of manganite liquid phase which filled the pores and clearance among minerals. The product pellets contain high Mn grade and low impurities, and can be used to smelt ferromanganese, which provides a possible way to use imported manganese ore fines containing high combined water to produce high value ferromanganese.
基金Projects(U1202274,51004033,51204040,50974035)supported by the National Natural Science Foundation of ChinaProjects(2010AA03A405,2012AA062303)supported by the National High Technology Research and Development Program(863 Prograam)of ChinaProject(N100302005)supported by the Fundamental Research Funds for the Central Universities,China
文摘The effects of magnetic field intensity, roasting temperature and roasting time on digestion rate and settling performance of bauxite with different iron contents were investigated systematically. The results indicate that such magnetic treatment can profoundly change the microstructure and digestion performance of bauxite. For the two samples carrying different iron contents, phase transformation of the aluminum oxide phase proceeds faster in the high iron bauxite than the low one. The optimal pretreatment conditions of low iron bauxite are roasting temperature 550 ℃ and magnetic field intensity 6 T, while for high iron bauxite are 500 ℃ and 9 T. The digestion rate of alumina can reach 95% and 92% at digestion temperature of 190 ℃ and 250 ℃. The settling performances of roasted ore by intense magnetic field after digestion are enhanced through pretreatment.
文摘To control contamination of flue gas emission NOx, the author mixcd method of preparing new magnesia base catalyst and researched on denitrificating fine gas by directness catalytic decomposition. Usually removal rate of NO is regarded on the main evaluation criteria. The author analyzed calcination temperature of catalyzer manufacturing process, the temperature of flue gas desorption tower, bed height and efficiency denitrification of NO concentration. And discussed the result of both denitrate lore-and-aft of FT-IR and XRD. The experiment indicates that magnesia base catalyst is available to directness catalytic decomposition denitrificate flue gas. Through denitrification rate is from 85% to 95%. The ingredient of magnesia base catalyst is made from magnesia, firming agent, addition agent. Height denitration bed was 4 cm- 5 cm, deuitration reaction temperature is 130℃-170℃, through the analyses above, presumed that magnesia base catalyst exist activating of vice, and analyzed this vice preliminarily.
基金supported by the National Natural Science Foundation of China (Grant No. 51406198)
文摘The CO_2 absorption ability of synthetic calcium-based sorbent modified by peanut husk ash (PHA) was tested by Thermal Gravimetric Analyzer (TGA), and the effects of steam and calcination temperature were investigated. The PHA composition was analyzed by X-Ray Fluorescence (XRF), the apparent morphology was characterized by scanning electron microscope (SEM), and the phases of the sorbent before and after calcination were examined by X-ray diffraction (XRD). The addition of PHA effectively improved the cyclic stability of the calcium-based sorbent. The optimal molar ratio of SiO_2 in PHA to CaO was around 0.07. Steam had positive effect on keeping porosity of the sorbent at the chemical reaction stage, and improved its CO_2 absorption ability. Steam also reduced the diffusion resistance of the product layer, and depressed the influence of high temperature calcination. It was also found that the steam hydration after calcination was an effective way to recover the absorption ability of the sorbent, while the hydration duration of 10 min was enough.
