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1.
采用生物质焦和活性炭粉作还原剂,在管式炉中进行了低品位软锰矿焙烧还原对比试验.分别研究了焙烧温度、焙烧时间、生物质焦用量等条件对软锰矿还原率的影响,对焙烧产物进行了X射线衍射分析.结果表明,生物质焦在焙烧时间和还原效率上优于活性炭粉;软锰矿焙烧还原依次经历Mn O2→Mn2O3→Mn3O4→Mn O过程;在焙烧温度为800℃,焙烧时间为50 min,生物质焦用量为10%时,软锰矿还原率可达98%以上,在此基础上导出了还原动力学方程,并证实还原过程由界面化学反应控制,表观活化能为43.896 k J·mol-1.  相似文献   

2.
为实现高硫煤矸石焙烧过程中的高效固硫,采用工业废渣硼泥作为固硫剂,对煤矸石进行固硫试验.针对单因素试验的不足,采用Box-Behnken响应面法探索固硫剂用量、焙烧温度、焙烧保温时间等对煤矸石固硫率的影响,明确了各因素之间的交互作用.研究结果表明:在固硫剂中镁与煤矸石中硫的质量比(mMg/mS)为9,焙烧温度620℃、焙烧保温时间100 min时,煤矸石固硫率达到89.35%.对煤矸石固硫影响最大的因素为固硫剂用量,其次为焙烧温度,焙烧保温时间(2 h内)的影响较小.焙烧温度和固硫剂用量之间具有显著的交互作用.通过该方法优化的煤矸石固硫工艺可为高硫煤矸石的资源化利用提供一定技术支撑.  相似文献   

3.
为了改变优质电池原料短缺的状况和充分利用低品位锰矿资源 ,研究了天然低品位二氧化锰矿在添加少量无污染添加剂的条件下 ,在 71 0℃下焙烧 2h ,可使矿石中MnO2 转化为Mn2 O3 .其转化率达 99 5 %以上 .同时对焙烧产物进行岐化反应所用的酸介质、酸用量和反应时间与歧化作用的关系进行了研究 .并对氯酸钠氧化歧化液中Mn2 的氧化效果进行了分析 ,提出了分步氧化歧化液中Mn2 的新工艺 .  相似文献   

4.
中浓度NOx废气治理的新工艺研究   总被引:1,自引:1,他引:0  
研究了用软锰矿吸收中浓度NOx,吸收母液经净化、浓缩、结晶产出MnNO3,MnNO3热分解产出纯MnO2 (产品 )和高浓度NOx 气体 ,该气体用水吸收生产硝酸 (产品 ) ,吸收尾气返回软锰矿吸收的新工艺 .研究表明该工艺技术可行 ,具有显著经济效益和环境效益 .  相似文献   

5.
针对氧化焙烧法处理低品位钼精矿中存在的钼氧化不完全、铼难挥发分离、有价元素(钼和铼)回收率较低等问题,采用焙烧试验、热重、物相和显微结构分析等研究两段焙烧强化氧化含铼低品位钼精矿中钼、铼的工艺及原理。研究结果表明:两段焙烧是实现钼、铼充分氧化的有效处理工艺。该工艺通过调节两段的温度和气流方向,改善气固对流条件,减小氧化焙烧过程的氧化差异,促进含钼和含铼矿物的深度氧化。在最佳工艺条件下(Ⅰ段焙烧温度675℃,焙烧时间1 h,气流由下至上;Ⅱ段焙烧温度625℃,焙烧时间2 h,气流由上至下),最终焙烧过程铼挥发率可达77.21%,焙烧产物中可溶钼质量分数提高到83.98%。相较于一段焙烧,两段焙烧各层产物的物相组成及微观结构一致,不存在未氧化的辉钼矿(MoS2)和氧化不完全的低价钼氧化物(MoO2),钼主要以MoO3形式存在。  相似文献   

6.
强化氧化对石煤钙化焙烧提钒的影响   总被引:4,自引:0,他引:4  
研究石煤钙化焙烧参数对提钒效果的影响,确定合理的焙烧参数:当焙烧温度为950℃,焙烧时间3 h,碳酸钙添加量为质量分数6%时,石煤焙烧料中钒的浸出率为63%。在此基础上研究增强氧化对提钒效果的影响,比较通空气和添加MnO2这2种情况下提钒的效果。用化学物相分析和钒价态分析等技术探讨加强氧化提高钒浸出率的原因。空气通入速度为0.48 L/h时,钒的浸出率为69%;MnO2添加量(质量分数)为3%时,钒浸出率为68%。研究结果表明,加强氧化后矿石的结构被破坏,V5+含量提高,生成更多易溶于酸的钒酸钙类物质。  相似文献   

7.
针对非均相贵重金属催化剂成本高,非均相过渡金属催化剂性能良好、成本低,但使用寿命短、易流失的特点,研制高效复合MnO2-Cu O-CeO2非均相过渡金属催化剂.采用正交实验对催化剂制备过程中的n(Cu)∶n(Mn)、Ce的摩尔分数、焙烧温度、焙烧时间进行探讨,确定最佳制备条件,并对其结构和组成通过扫描电镜分析、X射线衍射分析及热重分析进行表征.用该催化剂催化氧化模拟苯酚废水,对催化剂用量、氧化剂H2O2用量、反应温度、反应时间进行优化,确定最佳反应条件并利用其进行降解化工集装罐清洗废水的应用研究.研究表明催化剂MnO2-Cu O-CeO2的最佳制备条件为:n(Cu)∶n(Mn)=4∶6、Ce的摩尔分数为10%、焙烧温度为600,℃、焙烧时间为4,h.催化氧化法处理苯酚废水的最佳工艺参数:催化剂用量0.8,g/L、H2O2用量与COD比值为3、反应温度170,℃、反应时间1,h.化工集装罐清洗废水COD去除效果显著,COD去除率达到95%左右.  相似文献   

8.
本实验探讨研究了低品位辉钼矿(8.37%)在焙烧时温度、时间、通氧气次数、多种碱性熔剂对钼转化率的影响.实验结果表明:温度为625℃,时间为2 h,通氧气2次的条件下,Na2CO3∶N aN O 3∶M o=2:0.5:1(物质的量比)进行焙烧,此时转化率最高为96.76%  相似文献   

9.
调质鸡蛋壳的脱硫性能   总被引:1,自引:0,他引:1  
用NaOH、C_2H_5OH、Na_2CO_3和NaCl等对鸡蛋壳进行了调质,研究调质鸡蛋壳的脱硫效果,结果表明最佳的蛋壳调质剂为NaOH,经NaOH调质后蛋壳粉的最佳固硫温度为1 000℃,最佳,n(Ca):n(S)=2:1.实验比较了同一条件下NaOH调质蛋壳固硫剂、蛤壳和蚝壳等天然固硫剂在1 000℃下的脱硫效果,结果表明NaOH调质蛋壳的脱硫率最高,达到88.1%.SEM实验结果表明,氢氧化钠不但可以除去蛋壳的生物膜还能改善蛋壳表面的微观结构,有效地提高了蛋壳的脱硫率.  相似文献   

10.
将氧化亚铁硫杆菌(T.f)用于砷黄铁矿与软锰矿共同浸出,设置无菌体系作为对照,提出有氧和无氧条件下Fe As S-Mn O2的反应模型。研究结果表明:氧化亚铁硫杆菌对砷黄铁矿还原浸出软锰矿具有明显的催化作用,在砷黄铁矿与软锰矿的质量比为1:3.6、反应p H为1.8的最优条件下,有菌体系下锰的浸出率达99%,后续金的氰化浸出率达95%以上;Mn2+会抑制细菌的生长,当ρ(Mn2+)≥30 g/L时,Mn2+对细菌有致死作用;从软锰矿与砷黄铁矿的循环伏安曲线可看出两矿均有明显的氧化还原峰,且在有菌的条件下两矿的电化学活性要远远比无菌条件下的强;T.f菌的作用机理是催化Fe2+和Fe3+的相互转化。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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