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采用氧化焙烧脱炭-硫酸氧化浸出-P204+TBP溶剂萃取-氨水沉钒的工艺方法,从江西某石煤钒矿中提取V2O5,考察了硫酸用量、萃取及反萃次数、反萃液pH值对工艺过程的影响。试验结果表明:钒矿破碎后在硫酸溶液中用氯酸钠进行氧化浸出,钒的浸出率可达到96%以上;用P204+TBP溶剂萃取和稀硫酸溶液反萃,再用氨水沉淀钒,最终得到纯度98.0%以上的V2O5产品;从石煤钒矿到V2O5的总收率可达86.14%~93.09%。该工艺对钒的回收效果明显,操作简单,生产成本低,对环境污染较小。 相似文献
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摘要:为了对转炉提钒冶炼过程含钒炉渣熔化和流动性进行合理的控制,采用半球点法和内旋转黏度法分别测试了含钒炉渣熔化温度和黏度,采用XRD测试了含钒炉渣的物相,并采用综合碱度(BI′)反映渣中酸碱氧化物平衡关系。结果表明,在FeO质量分数一定的条件下,随着w(SiO2)/w(V2O3)增大,综合碱度由BI′>1单调下降至BI′<1,含钒炉渣熔化温度先降低后升高;随着FeO质量分数的增加,熔化温度最低点对应的w(SiO2)/w(V2O3)增大。随着w(SiO2)/w(V2O3)增大,黏度随温度变化的趋势变缓,高温熔融态含钒炉渣黏度增大,低温阶段黏度减小。综合考虑黏度对钢渣界面反应和钒渣流失的影响,FeO质量分数为44%时含钒炉渣w(SiO2)/w(V2O3)应控制为0.7。 相似文献
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《中国稀土学报(英文版)》2021,39(11):1370-1381
Excellent catalysts with low-temperature activity and relatively wide temperature window for selective catalytic reduction of NO with ammonia (NH3-SCR) are highly demanded in view of the practical treatment of NO. Herein, we have designed a highly active VOx-MnOx/CeO2 material based on the intrinsic requirement of SCR reaction for catalyst, namely redox sites and surface acid sites. The vanadium oxide and manganese oxide are highly dispersed over the ceria mesosphere via simple incipient wetness impregnation. The loading of manganese could introduce acid sites and enhance the redox property remarkably, while the loading of vanadium increases acid sites and weakens redox property. Through tentatively controlling the appropriate loading ratio of the two components, the optimal catalyst achieves a balance between redox property and surface acidity. The work shed light on the development of new SCR catalyst with superior low temperature activity, wide work temperature window and good hydrothermal stability. 相似文献
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以某含钒页岩草酸浸出液为对象,研究了钒和铝在含钒页岩草酸浸出液中的赋存状态。首先采用Medusa软件初步确定了钒和铝在草酸体系中的存在形式,然后对钒和铝的负载有机相分别进行红外光谱和质谱研究。结果表明:钒负载有机相萃合物化学式为[(R_4N)_2·VO(C_2O_4)_2],铝负载有机相萃合物的化学式分别为[(R_4N)·Al(C_2O_4)_2]和[(R4N)3·Al(C_2O_4)_3],因此可以确定含钒页岩草酸浸出液中钒主要以VO(C_2O_4)_2~(2-)络合阴离子存在,而铝主要以Al(C_2O_4)_2~-和Al(C_2O_4)_3~(3-)形式同时存在。 相似文献
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根据熔渣结构的分子离子共存理论建立了CaO-SiO2-Al2O3-V2O3四元系活度模型。应用该模型计算出的活度数据,对用钒氧化物矿代替钒铁直接合金化冶炼高速钢的工艺过程进行了热力学计算和分析。用此活度数据计算了Al作还原剂时渣的平衡成分。计算结果表明,渣中V2O3的质量分数极低,直接合金化的热力学条件好,钒的理论最大还原率高。通过计算钢中或渣中的各种还原剂还原渣中V2O3的ΔG和LV,表明在炼钢工艺常用的所有还原剂中,Al的还原能力最强。 相似文献
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炉缸区钒氧化物的还原对钒的收得率具有重要影响。通过研究炉渣成分和温度对钒氧化物还原的影响,结果表明:二元碱度对钒氧化物还原影响显著,钒氧化物的还原率随着二元碱度的增加而增加;MgO、Al_2O_3含量增加,钒氧化物的还原率先升高后降低;TiO_2含量增加,钒氧化物的还原率降低,且TiO_2含量超过11%时钒氧化物的还原率大幅降低;钒氧化物的还原率随着温度的增加而升高。当承钢高炉渣的二元碱度1.2、Al_2O_3含量14%、MgO含量10%、TiO_2含量9%、炉渣温度控制1 500℃时,钒氧化物的还原达到最佳,还原率达到90%左右。 相似文献
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����ƽ��̷گ������䣬֣Ϫ�� 《钢铁研究学报》2013,25(8):24-27
High vanadium ferrovanadium was smelted with mixture of V2O5 and V2O3 as raw material, Al-Ca-Fe alloy as refine agent, and its technological parameters were investigated. The optimum conditions are defined: the amount of aluminium is 103% theoretical amount, the addition of refine agent is 100g, the refining time is 30min, and the recovery of high vanadium ferrovanadium is 98%. The optimum addition of refine agent is 100g. If the addition of refine agent is bigger than the optimum addition, the amount of Al in high vanadium ferrovanadium is increased with the refine agent increasing. 相似文献
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Selective catalytic oxidation(SCO) of ammonia was carried out over Cu-Mn compounds catalysts modified with trivalent rare earth oxide Ce2O3 and La2O3 respectively.TiO2 was used as support and different ratio of O2 were tested in order to find an appropriate O2 concentration(vol.%),and the results showed that 1%O2(vol.%) was propitious to SCO of ammonia.The effects of the two rare earth oxides modified catalysts Ce2O3-Cu-Mn/TiO2 and La2O3-Cu-Mn/TiO2 on the catalytic activity and selectivity of ammonia oxidation were investigated under the reaction condition of 500 ppm ammonia,1%O2(vol.%),at the temperature from 125 to 250 oC.The results revealed the beneficial role of Ce2O3 and La2O3 in catalytic activity at low temperature and lean oxygen concentration,while the modification with Ce2O3 and La2O3 led to the negative influence on N2 selectivity.For the catalysts modified with Ce showed lower NO and N2O selectivity than the catalysts modified with La,then the effects of different Ce loadings on catalytic activity and selectivity were also considered,in combination with catalysts preparation methods,which include incipient wet impregnation,sol-gel method and co-precipitation.Results revealed that the catalysts prepared by sol-gel method obtained preferable catalytic activity compared with the others,reaching 99% ammonia at 200 oC,whereas 96% NO was detected.It also indicated that different catalyst preparation method significantly determined production distribution. 相似文献
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采用硫酸浸出和萃取分离从提钒尾渣中回收有价元素。结果表明,尾渣经80%质量浓度的硫酸溶液浸出后,钒、铬浸出率分别达98.2%、84.8%;以20%P204+80%磺化煤油(体积百分数)为萃取剂,对浸出液进行三级萃取并反萃后,钒的回收率可达56.2%,萃取过程中铬的损失率低于4%,萃余液水解后可得到纯度为89.6%的Cr_2O_3产品。实现了浸出液中钒、铬的分离和回收。 相似文献
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YIN Yan-bing YANG Yu-lin FAN Rui-qing ZHU Yang-qing SUN Ji-ru 《Canadian Metallurgical Quarterly》2011,27(3)
Four new vanadium substituted Dawson-type heteropoly acids H<,7>[P<,2>Mo<,17>VO<,62>]·39H<,2>O(1), H8[P2Mo16V2O62]·41H2O(2) H9[P2Mo15V3o62]·51H2O(3)and H8[P2Mo14V4O62H2]·45H2O(4)were prepared respectively. Their structures were determined by IR and ICE. The inhibition effects of vanadium substituted Dawson-type heteropoly acids(Mo, P) on free radical polymerization of methyl methacrylate(MMA) were investigated by dilato- metry. The results show that the rate of the polymerization of MMA decreases and the inhibition effects of the four heteropoly acids reach the inhibitor performance of hydroquinone at a certain ratio. 相似文献
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Increasingly stringent regulations in many countries require effective reduction and control of NOx emissions. To meet these limits, various methods have been exploited, among which the selective catalytic reduction of NOx using ammonia as the reductant(NH3-SCR) is the most favored technology. High catalytic activity, N2 selectivity and resistance to deactivation by sulfur, alkaline metals and hydrothermal conditions are the optimal properties of a successful SCR catalyst. Rare earth oxides, particularly CeO2, have been increasingly used to improve the catalytic activity and resistance to deactivation of deNOx catalysts, both modifying traditional vanadium catalysts, and also developing novel catalysts, especially for low temperature applications. This review summarized the open literature concerning recent research and development progresses in the application of rare earths for NH3-SCR of NOx. Additionally, the roles of rare earths in enhancing the performance of NH3-SCR catalyst were reviewed. 相似文献
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为了研究钒在攀钢转炉中的热力学行为及分配,根据钒渣的成分对CaO-MgO-Al2O3-V2O3-SiO2熔渣中各组元的活度进行研究。应用分子相互作用体积模型(MIVM)及其伪多元法预测MgO-Al2O3-SiO2、CaO-V2O3-SiO2、CaO-MgO-Al2O3-SiO2渣系中某组元的活度值,并与试验值对比。结果表明,MIVM伪多元法预测值与试验值吻合良好,MgO-Al2O3-SiO2渣系中Al2O3的平均相对误差为15%;CaO-V2O3-SiO2渣系中V2O3的平均相对误差为33%;CaO-MgO-Al2O3-SiO2渣系中SiO2的平均相对误差为13%。在此基础上,利用MIVM预测CaO-MgO-Al2O3-V2O3-SiO2熔渣中各组元的活度,并将V2O3的预测值与试验值对比分析,结果表明,预测值与试验值吻合良好,都呈正偏差,平均相对误差为44%,V2O3的活度随碱度的提高而下降。 相似文献
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DeterminationofTraceAmountofVanadiuminHighPurityY_2O_3byElectrothermalVaporization-ICP-AESwithBi(PDC)_3CoprecipitationHuBin;Ya?.. 相似文献
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根据熔渣结构的分子离子共存理论建立了CaO-SiO2-Al2O3-V2O3四元系活度模型,应用该模型计算出的活度数据,对用钒氧化物矿代替钒铁直接合金化冶炼高速钢的工艺过程进行了热力学计算和分析.用此活度数据计算了Al作还原剂时渣的平衡成分,计算结果表明渣中V2O3的含量极低,直接合金化的热力学条件好,钒理论最大还原率高.通过该活度数据计算钢中或渣中的各种还原剂还原渣中V2O3的△G和Lv,计算结果表明Al是所有还原剂中还原能力最强的. 相似文献