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1.
1 INTRODUCTIONTibasedIrO2 coatinganodeswerewildlyusedinelectrochemicalindustryfortheirhighelectrocatalyticactivityandstability[1] .Inanextremecondition ,suchashigh speedelectrodeposition ,however ,thestabilityofIrO2 isnolongersatisfied .Therefore ,themodificat…  相似文献   

2.
Chemical stability of La_2O_3 in La_2O_3-Mo cathode materials   总被引:1,自引:0,他引:1  
1 INTRODUCTIONThO2 Wthermioniccathodesarestillwidelyusedinhigh powervacuumtubesforindustrialheat ing .ItiswellknownthattheradioactivityofThO2leadsproblemstoitsmanufactureandapplication .La2 O3 Mo ,oneoftheattractivealternatives,wasin ventedinthemidstof 1970s[1~ …  相似文献   

3.
1 INTRODUCTIONOverthree fifthsearth’ssurfaceiscoveredbyo ceans .Thoughpetroleumisproducedfromhugede positsontheshallowcontinentalshelf,theimmenseareaoftheoceanrepresentsalargelyunexploredandunexploitedvirgingroundreservingastoreofmineralresourcese .g .mul…  相似文献   

4.
1 INTRODUCTIONMassandchemicalchangetechniquesareusedinexplorationfields .The procedureutilizeselementswithhighdegreeofimmobilityinhydrothermalandassociatedinteractivefluid rocksystems .Theseele mentsnotablyZr ,TiO2 ,Y ,Sc ,Nb ,REEandAl2 O3 arehighlyimmobileduri…  相似文献   

5.
1 INTRODUCTIONTherearetwotypesoforbitalsinouterelectronorbitalsofgoldanditslixiviants[1,2 ] .OneiscalledHOEO(higheroccupiedelectronicorbitals) ,suchasπ typeHOEOofboth 5d2(x2 -y2 ) and 5d2zofgold ,andσ typeHOEOofσ22 pxofcyanide;andanothercalledLUEO(lowerunoccupiedelect…  相似文献   

6.
Removal of sulfur in coke oven gas by mixing ZnO-based additive into coal   总被引:3,自引:0,他引:3  
1 INTRODUCTIONSulfurdistributionincokingprocessincludestwoparts .OnepartisgoingintoCOGasH2 S ,CS ,COSandC2 H2 SH .TheotherpartisresidualincokeasFeS ,CaS ,S2 andsoon .Traditionally ,theremovalofsulfurofCOGisbysprayingammoniawaterintohotcoalgastoformammoniumsulfat…  相似文献   

7.
Separating titania from treated slag by gravity separation or flotation   总被引:9,自引:2,他引:7  
1 INTRODUCTIONChinaisatitaniumrichcountry ,whose92 .4 %oftitaniumresourceisvanadium titaniumbearingmagnetite .About 53%titaniumwereinironconcen trateaftermineralprocessing ,bywhichtheblastfur naceslagcontainingabout 2 5%TiO2 were pro duced[1] .ThecontentofTiO2 insuchs…  相似文献   

8.
1 INTRODUCTIONHighsulfurcoaloccupiesalarge partofthewholedepositofcoalintheSouth WestandtheEastofChina .Withoutwashinganddesulfurizating ,thecommercialcoalisoflowquality ,lowcombustionef ficiencywithlargecoalwasting ,gasash ,CO2 andNOx .Aboveall,thecombustion…  相似文献   

9.
1 INTRODUCTIONSinceZnOvaristorceramicswerefirstlydevel opedin 196 8,significantprogresseshavebeenmadeininvestigationandapplicationofthematerial.Asakindofadvancedfunctionalceramics,ZnOvaristorceramicshavebeenwidelyusedinelectroniccircuitsandelectricalpower…  相似文献   

10.
Carbonization kinetics of La_2O_3-Mo cathode materials   总被引:7,自引:0,他引:7  
1 INTRODUCTIONCarbonizationofcathodeisakey processinThO2 Wcathodemanufacture .WhenThO2 Wfila mentsareheatedinahydrogenatmosphereconsistingofbenzene ,acetylene ,naphthaleneorxylenevapors ,thehydrocarbonisdecomposedatthehotfilamentsurfacetoformditungstencarb…  相似文献   

11.
氯化钠对铝硅矿物浮选的影响及其作用机理   总被引:4,自引:0,他引:4  
采用季铵盐DTAL作捕收剂,研究了氯化钠对一水硬铝石和叶蜡石浮选的影响及其作用机理.随着氯化钠浓度的增加,叶蜡石的浮选回收率显著提高,而一水硬铝石的可浮性受其影响很小.机理研究表明:氯化钠对一水硬铝石的zeta-电位没有影响,而能显著降低叶蜡石的zeta-电位,增强捕收剂与叶腊石的静电作用,促进捕收剂的吸附而活化其浮选;叶蜡石表面电位的降低是因为氯离子对叶蜡石存在选择性吸附作用并对其结构进行插层,使得叶蜡石的层间距从0.93 nm增大至1.40 nm.溶液化学计算表明:氯化钠改变溶液的离子强度,显著降低了季铵盐阳离子表面活性剂的临界胶束浓度,使得吸附了捕收剂的矿物表面更容易疏水上浮.  相似文献   

12.
Flotation of kaolinite and its interaction with hexadecylammonium bromide   总被引:1,自引:0,他引:1  
1 INTRODUCTIONAshasbeenextensivelydiscussedinRef .[1],theselectiveseparationofbauxiteisextremelycom plexinseveralcases ,theproblemsinvolvedarenotyetfullyresolved .Thetechnologicalschemesofposi tive flotationorreverse flotationseparationofalu minum silicatemineralsfromdiasporicbauxiteweresuggested[2 ,3] .The positive flotationseparationofbauxiteisfinishedbydepressingaluminumsilicateganguemineralssuchasillite ,kaoliniteandpy rophillite,andusesanioniccollectorstofloatdias pore .Phosphate ,s…  相似文献   

13.
It is important to depress diaspore effectively in order to remove silicates from diasporic bauxite.A new water soluble polymer hydroxamic acid starch(HA-starch)was prepared.The effects of the product on the diaspore and kaolinite flotation were investigated and its reactive mechanism was studied by zeta potential measurement and FTIR.The results show that HA-starch can depress diaspore while make positive effect on kaolinite flotation at low pH value(pH below 6)The flotation recovery of diaspore was sharply decreased with the increase of concentration of HA-starch.The chemical adsorption of HA-starch on the surface of diaspore was revealed.  相似文献   

14.
硬质和软质高岭石的晶体结构与浮选行为   总被引:5,自引:0,他引:5  
研究了硬质与软质高岭土中的高岭石晶体结构、晶体形态与表面性质之间的关系及其对浮选行为的影响。硬质和软质高岭土表面Zeta电位随pH值的变化规律基本相同,具有相近的表面零电点(PZC)值。几种硬质高岭土的PZC值的变化范围为2.5-3.8。在较宽的pH值范围,软质高岭土比硬质高岭土的电位高。铝土矿中高岭石以硬质高岭石为主,结晶有序度低,与药剂作用不强,可浮性较软质高岭石差,在铝土矿反浮选中,需强化对高岭石的捕收作用。  相似文献   

15.
Aluminum-silicates flotation with quaternary ammonium salts   总被引:1,自引:0,他引:1  
1 INTRODUCTIONThediasporic bauxiteinChinaisdifferentfromthegibbsite bauxiteandboehmite bauxiteinothercountriesbyitshighcontentofAl2 O3andSiO2 andlowmassratioofAl2 O3toSiO2 (massratioofAl2 O3toSiO2 =A/S ,usually5 6 ) .Theproductioncostofa luminumoxidefromsuchrefractorybauxiteby“sin tering”or“combining”technologiesismuchhigherthanthatbyBayer sprocess .Sothatthealuminum silicateganguessuchaspyrophyllite ,illiteandkaolin iteinthebauxiteisneededtoberemovedtoincreaseA/S .Hussainetal…  相似文献   

16.
Medialan has preferable flotation performance to wolframite,under the conditions of the best flotation pH value 7.0 and low dosage,wolframite recovery is up to80%.Medialan shows poor flotation performance to quartz,but better to fluorite and calcite.However,fluorite and calcite are inhibited in a certain degree by adding medialan mixed with sodium silicate.Adsorption mechanism of medialan collector on wolfram surface was also studied by using infrared(IR)radiation spectrum,adsorption volume,and zeta potential.The results show that medialan can adsorb on wolfram surface in the form of chemistry adsorption,and as medialan collector dosage changes,change law of adsorption volume is similar with that of wolfram pure mineral flotation.Zeta potential results prove that zeta potential of wolfram surface moves negatively after adsorbing medialan collector.  相似文献   

17.
一水硬铝石型铝土矿铝硅浮选分离的溶液化学   总被引:30,自引:3,他引:27  
分析了我国铝土矿中一水硬铝石和铝硅酸盐脉石矿物的晶体结构与表面性质,一水硬铝石与铝硅酸盐脉石矿物晶体结构的差异、表面断裂的Al-O和Si-O健及表面离子活性区的差别,可影响矿物表面的润滑性与可浮性,类质同象及各种晶格杂质离子也将影响浮选剂与矿物表面的相互作用和矿物可磨性,提出了正浮选、反浮吕硅分离的技术原型,用溶液化学与计算研究了其基本原理。结果表明,通过溶液化学计算可确定阴离子捕收剂正浮选脱硅时捕收剂,分散剂和PH三者之间的匹配关系,矿物的PZC与捕收剂的pKa值是阳离子捕收剂反浮选的主要控制参数,阴离子捕收剂反浮选时,铅盐和钙盐是浮选铝硅酸盐较理想的活化剂。  相似文献   

18.
研究取代度不同的两种羧甲基淀粉(CMSL和CMSH分别表示取代度低和取代度高的羧甲基淀粉)在以十二胺(DDA)为捕收剂的阳离子反浮选中对一水硬铝石的抑制性能。考察了CMS的取代度对其抑制性能及作用方式的影响。单矿物浮选实验表明,在广泛pH值范围内,CMSL对一水硬铝石的抑制能力要好于CMSH。借助吸附量测试、动电位测量和原子力显微镜对CMS在一水硬铝石表面的吸附进行研究。结果表明:相对于CMSL,CMSH分子中具有更多的吸附点,因而在一水硬铝石表面具有较小的吸附量和较薄的吸附层厚度,并使一水硬铝石表面具有较强的电负性。溶液表面张力的测定和捕收剂DDA的吸附实验进一步揭示,CMSL分子的环式吸附构象可以罩盖更多的DDA从而显示优良的抑制性能,而CMSH/DDA体系则表现得更像一种表面活性剂。  相似文献   

19.
变性淀粉在铝硅矿物浮选分离中的作用机理   总被引:22,自引:2,他引:20  
通过浮选实验、动电位和红外光谱测定,详细考察了变性淀粉在铝硅矿物浮选分离中的作用效果和机理。浮选实验显示:非离子淀粉和阴离子淀粉在pH<6时,抑制一水硬铝石的浮选,但当pH>6时,却对一水硬铝石浮选有活化作用;阳离子淀粉在较宽pH值范围内对一水硬铝石均有抑制作用;3种淀粉化合物在pH<6时均活化高岭石的浮选,当pH>6时活化作用较微。结果表明:变性淀粉是一水硬铝石型铝土矿反浮选中实现一水硬铝石和高岭石分离的有效调整剂,阴离子淀粉使矿物表面ζ电位更负,阳离子淀粉使矿物质表面ζ电位更正,非离子淀粉使矿物表面电位绝对值减小。由实验结果结合药剂与矿物作用前后的红外光谱分析,得出结论:非离子淀粉主要通过氢键作用吸附于矿物表面,而静电力和化学键合力在阴离子淀粉和阳离子淀粉吸附中发挥着重要作用。  相似文献   

20.
The floatability of diaspore and three kinds of silicate minerals,including kaolinite,illite and pyrophyllite,by a cationic Gemini surfactant as collector and starch as depressant was investigated as function of reagents concentration and pulp pH.Further studies of artificially mixed minerals and bauxite ore were also detailedly conducted.At last,the pre-desliming reverse flotation separation process was adopted.It can be concluded that the combinational use of a Gemini cationic collector and the starch dep...  相似文献   

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