Ce~(3+)和钼酸钠对X80钢的缓蚀协同效应

为了研究稀土与钼酸盐之间的缓蚀协同效应,采用失重法和电化学法研究了盐酸介质中,Na2MoO4、Ce(NO3)3以及Na2MoO4-Ce(NO3)3复合缓蚀剂对X80管线钢的缓蚀作用。根据动电位极化曲线法计算了钢试样在不同的盐酸溶液中,发生溶解反应的动力学与热力学参数(表观活化能Ea、反应焓变ΔHa以及反应熵变ΔSa),证明了实现缓蚀反应的可能性和现实性,同时表明Na2MoO4-Ce(NO3)3复合缓蚀剂的存在使钢试样表面形成了一层更有序致密的薄膜,因此增大了钢试样发生溶解反应的表观活化能,降低了腐蚀速度。通过对比实验发现,Na2MoO4和Ce(NO3)3对X80管线钢产生了明显的协同缓蚀作用,且缓蚀效率及其相关参数受到温度变化的明显影响。     

La、Ce掺杂对水热法合成镍锌铁氧体的影响

采用水热合成法制备镍锌铁氧体粉体,以稀土元素La、Ce进行掺杂,利用SEM和XRD 等手段对样品进行表征.结果表明,La3+、Ce3+掺杂后,La3+、Ce3+离子掺杂进入镍锌铁氧体晶格后,会产生一定的晶格畸变,造成晶粒常数的增大,但对晶体的形貌影响不大.除存在少量大颗粒,立方尖晶石相Ni0.35Zn0.65Fe1.9...     

盐酸介质中Ce(NO_3)_3/CTAB复配对碳钢表面的缓蚀性能

采用失重法、电化学极化法、交流阻抗法和扫描电镜法研究了Ce(NO_3)_3/CTAB复配体系对碳钢的缓蚀性能,发现虽然Ce(NO_3)_3单组分对碳钢表面基本上没有缓蚀作用,但二者复配后仍能够达到CTAB单独使用的缓蚀能力,缓蚀效率达到90%以上,即使CTAB含量α1=0.1时,三种方法测试的缓蚀效果均为95%以上。说明在盐酸介质中Ce(NO_3)_3可以代替部分CTAB作为缓蚀剂,起到绿色环保的作用。     

稀土对碳素钢在模拟工业性大气腐蚀环境下耐蚀性的影响

 利用浸泡、电化学方法研究了Ce/La混和稀土对碳素钢在腐蚀介质中的缓蚀作用,采用相分析、周浸、锈层分析等方法研究了稀土对碳素钢耐工业性大气腐蚀性能的影响。结果表明：在模拟工业性大气腐蚀环境的酸性NaHSO3溶液中,稀土丝分解后生成的稀土离子是一种混合型缓蚀剂;在对碳素钢的缓蚀过程中,Ce/La离子沉积于同一区域;随钢中稀土含量增加,钢中相界固溶稀土和稀土/铁金属间化合物总量增加,钢的耐蚀性得到大幅度提高。另外,还对稀土减缓钢铁腐蚀过程进行了讨论,提出了稀土对碳素钢的缓蚀机理。     

十二烷基磺酸钠及其复配体系在盐酸介质中对铝的缓蚀作用

本文采用失重法研究１ｍｏｌ／Ｌ盐酸介质中，十二烷基磺酸钠（ＳＤＳ）在铝表面上的吸附规律及其缓蚀作用，同时研究了十二烷基磺酸钠复配体系ＳＤＳ－ＴＸ－１００对铝的协同效应，探讨了协同作用机理。     

铅锌矿中铅锌快速连续测定

采用盐酸、硝酸、硫酸分解试样,铅形成硫酸铅沉淀而与锌分离.以慢速滤纸过滤,滤液用EDTA络合滴定分析法测定锌量;沉淀以HNO3(1+1)溶解后,在pH5.5～6.0的乙酸-乙酸钠缓冲溶液中,以二甲酚橙为指示剂,用EDTA标准溶液滴定铅量.     

Cr3+或V3+替代Mn3+对La0.4Ca0.6MnO3电荷有序相的影响

用固相反应法制备了La0.4 Ca0.6 Mn1 -xCrxO3(LCMCO)和La0.4Ca0.6Mn1-yVyO3 (LCMVO)(x,y=0.00,006,0.08)多晶样品.通过XRD、M-T曲线、ESR谱线,研究了Cr3+或V3+替代Mn3+对La0.4Ca0.6MnO3电荷有序相的影响.实验结果表明:电荷有序相随着Cr掺杂浓度的增加而被破坏,在LCMCO体系中电荷有序相几乎完全消失;而当V掺杂时,虽然电荷有序相随着V成分的增加会逐渐变弱,但电荷有序相依然存在于LCMVO体系中.用V3+替代Mn3+只是对于长程的电荷有序仅仅起了隔断的作用;用Cr3+替代Mn3+破坏了CE型反铁磁的自旋序从而引起电荷序的融化.从实验上证明了电荷序CE型反铁磁体系中,电荷序和自旋序存在强耦合相互作用.     

离子交换分离-Na2EDTA滴定法测定含镍钴锌精矿中锌的改进

随着锌资源的日益枯竭,锌精矿的成分也越来越复杂化,准确测定锌精矿中锌含量具有重要意义。试验以盐酸-氟化铵-硝酸-硫酸-高氯酸溶解样品,在盐酸(1+5)的介质中,用大孔型强碱性阴离子树脂分离镍、钴、铁、锰、铝等,用氨水-氯化铵溶液洗脱Zn²⁺,在分离杂质后的溶液中加入少量氟化铵掩蔽残余的铁,硫代硫酸钠溶液掩蔽微量铜,用Na₂EDTA标准滴定溶液直接滴定锌、镉合量,扣除镉量即为锌量,建立了离子交换分离-Na₂EDTA滴定法测定含镍钴锌精矿中11%～62%锌的方法。研究了金属离子在3种典型强碱性阴离子树脂上,不同酸度下的分配系数K_d,最终选择了在D296型大孔型强碱性阴离子交换树脂上、盐酸(1+5)介质中进行离子交换分离。试验结果表明少量NH⁺₄的存在不影响Zn²⁺的吸附,离子交换柱柱高为30 cm时吸附损失率小于0.10%,样品溶液通过离子交换柱的流速为8～10 mL/min时工作效率较高,吸附损失率低。方法用于测定3个含镍钴锌精矿样品中锌,测定结果与使用氢氧化钠沉淀分离-EDTA滴定法及丁二酮肟沉淀分离-EDTA滴定法结果基本一致,结果的相对标准偏差(RSD,n=11)为1.6%～5.6%。     

离子交换分离-Na2EDTA滴定法测定含镍钴锌精矿中锌的改进

随着锌资源的日益枯竭,锌精矿的成分也越来越复杂化,准确测定锌精矿中锌含量具有重要意义。试验以盐酸-氟化铵-硝酸-硫酸-高氯酸溶解样品,在盐酸(1+5)的介质中,用大孔型强碱性阴离子树脂分离镍、钴、铁、锰、铝等,用氨水-氯化铵溶液洗脱Zn²⁺,在分离杂质后的溶液中加入少量氟化铵掩蔽残余的铁,硫代硫酸钠溶液掩蔽微量铜,用Na₂EDTA标准滴定溶液直接滴定锌、镉合量,扣除镉量即为锌量,建立了离子交换分离-Na₂EDTA滴定法测定含镍钴锌精矿中11%～62%锌的方法。研究了金属离子在3种典型强碱性阴离子树脂上,不同酸度下的分配系数K_d,最终选择了在D296型大孔型强碱性阴离子交换树脂上、盐酸(1+5)介质中进行离子交换分离。试验结果表明少量NH⁺₄的存在不影响Zn²⁺的吸附,离子交换柱柱高为30 cm时吸附损失率小于0.10%,样品溶液通过离子交换柱的流速为8～10 mL/min时工作效率较高,吸附损失率低。方法用于测定3个含镍钴锌精矿样品中锌,测定结果与使用氢氧化钠沉淀分离-EDTA滴定法及丁二酮肟沉淀分离-EDTA滴定法结果基本一致,结果的相对标准偏差(RSD,n=11)为1.6%～5.6%。     

W-Ce复合缓蚀剂对X80管线钢的缓蚀性能及机理研究

为了研究Na_2WO_4·2H_2O、Ce(NO_3)_3·6H_2O单一缓蚀剂以及Na2WO_4·2H_2O-Ce(NO_3)_3·6H_2O(简写为:W-Ce)复合缓蚀剂对X80管线钢的缓蚀作用,采用失重法计算钢试样在不含和含有不同缓蚀剂的中性Na Cl介质中的缓蚀效率,结合SEM表征确定出,在35℃恒温条件下,780 mg·L~(-1)Na_2WO_4·2H_2O与660 mg·L~(-1)Ce(NO_3)_3·6H_2O复配得到的W-Ce复合缓蚀剂具有最高的缓蚀效率,达99.01%。根据EDS分析和多酸配合物的理论,探究了W-Ce复合缓蚀剂的缓蚀机理和模型。最终认为,W-Ce复合缓蚀剂对X80钢片的缓蚀作用,主要是通过Ce~(3+)和WO_4~(2-)形成的杂多酸[Ce(WO_4)_3]_n~(3-)与钢片表面的Fe配位吸附作用,形成一层缓蚀膜,从而隔绝腐蚀介质,产生了优良的抑制腐蚀效果。     

Corrosion Inhibition Synergism between Lanthanum （ Ⅲ ） Ion and 8-Hydroxyquinoline for Zinc in Hydrochloric Acid

The effects of La^3 ion and chelate reagent 8-hydroxyquinoline on the corrosion rate of zinc in hydrochloric acid were investigated by using weight loss method and electrochemical method. It is found that in a specific concentration range of La^3 ion and 8-hydroxyquinoline, the obvious corrosion inhibition synergism is obtained.The mechanism of corrosion inhibition synergism was discussed on basis of adsorption theory.     

Inhibition Effect of Azadirachta indica,a Natural Product,on the Corrosion of Zinc in Hydrochloric Acid Solution

The corrosion behavior of zinc in 0.2 M hydrochloric acid solution by Azadirachta indica (AI-Neem) was investigated using mass loss, electrochemical polarization and impedance methods. Inhibition efficiency depends on the concentration of AI-Neem and it reaches maximum value at 1,000 ppm. The shape of polarization profile indicated that AI-Neem is a mixed type inhibitor with predominant cathodic effect. Adsorption of AI-Neem on the zinc surface follows Temkin adsorption isotherm. The surface morphology of zinc was studied by using scanning electron microscope images.     

A Study of Aluminium Corrosion Inhibition in Acid Medium by an Antiemitic Drug

The inhibition effect of meclizine hydrochloride on the corrosion behaviour of aluminium in 1 M hydrochloric acid medium was studied by weight loss, potentiodynamic polarisation and electrochemical impedance spectroscopy techniques. Results obtained revealed that Meclizine performed excellently as a corrosion inhibitor for aluminium in HCl medium at 303 K. The effect of temperature on inhibition efficiency was studied. The inhibition was assumed to occur via adsorption of the inhibitor molecule on the metal surface. The adsorption of the inhibitor on the aluminium surface followed Langmuir adsorption isotherm model. The values of activation energy and thermodynamic parameters were calculated and discussed.     

Inhibition Effects of Chloroquinolines on Corrosion of Mild Steel in Hydrochloric Acid Solution

The corrosion inhibition efficiencies of four compounds namely N-[(1E)-(2-chloroquinolin-3-yl)methylene]-N-phenylamine(CQMA),N-(1E)-(2-chloroquinolin-3-yl)methylene]-N-(4-fluorophenyl)amine(CQMFA),N-(4-chloro phenyl)-N-[(1E)-(2-chloroquinolin-3-yl)methylene]amine(CQMCA),and N-(4-bromo phenyl)-N-[(1E)-(2-chloroquinolin-3-yl)methylene]amine(CQMBA)on mild steel corrosion in hydrochloric acid media were investigated using mass loss,potentiodynamic polarization and electrochemical impedance spectroscopy.For all the studied inhibitors the inhibition efficiency values were found to increase with increasing concentration up to 5.00×10-4 mol·dm-3.Scanning electron microscopic technique showed the formation of a thick film on the steel surface in the presence of inhibitors.     

Adsorption and Corrosion Inhibition Performances of 1-Tetradecylphosphonic Acid Self-Assembled Monolayers on 430 Stainless Steel Surface

The self-assembled monolayers (SAMs) of 1-tetradecylphosphonic acid (TDPA) formed on the 130 stainless steel (SS430) were studied. Surface and morphological characterizations were studied by Fourier transformed infrared spectroscopy (FTIR), water contact angle measurement and atomic force microscopy (AFM). And the electrochemical study on the corrosion inhibition of the SAMs was performed by polarization curve and electrochemical impedance spectroscopy (EIS) for evaluating the corrosion protection of the SAMs. The results show that TDPA was able to form a film spontaneously on the SS430 surface and the hydrophobic SAMs could protect SS430 from corrosion effectively. In addition, the oxide surface formed by the heat pretreatment could accelerate the rate of adsorption, but had little effect on improving the inhibition efficiency.     

Metol as Corrosion Inhibitor for zinc

The inhibition behavior of metol (N-methyl-p-aminophenol sulphate) on zinc in different corrosive solutions at room temperature was investigated by various techniques such as weight loss, polarization and linear polarization methods. The percentage inhibition efficiencies were evaluated at different concentrations of the inhibitors. The corrosion rate, inhibition efficiency and surface coverage were dependent on metol concentration. The electrochemical data indicated a basic modification of zinc surface resulting in a decrease in the corrosion rate. Corrosion inhibition was explained by considering an interaction between metal surface and the inhibitor. SEM images and FT-IR profiles confirmed the formation of passive film on the metal surface.     

Research on anti-corrosion property of rare earth inhibitor for X70 steel

Three kinds of rare earth nitrates were adopted to sodium molybdate to get three kinds of LnN-M compounded inhibitors(La(NO3)3+Na2MoO4(LaN-M),Ce(NO3)3+Na2MoO4(CeN-M),Pr(NO3)3+Na2MoO4(PrN-M)).The combination of weight-loss method and the electrochemical test,was used to evaluate and analyze the corrosion inhibition efficiency of these LnN-M inhibitors to make the research on their corrosion inhibition performance,and the sequential order of their performance was found as follows:CeN-M> LaN-M>PrN-M,among which,the inhibition efficiency of CeN-M for the X70 steel could reach 98.21%.The synergism parameters were calculated by weight-loss method,these computational data indicated that the synergistic effect between rare earth nitrates and sodium molybdate was obvious and significant.Surface morphology,chemical composition and phase components of the precipitation films were tested for discussing the mechanism of LnN-M inhibitors.The outer electronic configuration of the lanthanide was found to have an important influence on the inhibition efficiency.The CeN-M inhibitor was discovered to have the best inhibition effect with the amorphous cerium oxides.The results of this research revealed that the precipitation films formed on the surface of the steel samples had a crucial influence on the inhibition efficiencies after adding LnN-M inhibitors.     

酸雨对钢质储酸罐腐蚀的分析

针对株洲冶炼厂硫酸库储酸罐外表的腐蚀情况进行分析，认为当地的降雨情况、空气温度、风向等因素对加剧储酸罐的腐蚀有相当重要的影响。提出在储酸的建设中，如果能结合具体情况深入探讨环境因素对腐蚀的影响，将有助于进一步降低防腐成本、延长储酸罐的使用寿命。     

Effect of lanthanum addition on microstructure and corrosion behavior of Al-Sn-Bi anodes

Novel Al-Sn-Bi anodes with and without lanthanum (La) were prepared.To evaluate the corrosion properties of the anodes,constant current and dynamic loop tests were carried out to determine its efficiency and corrosion rate.Optical microscopy (OM),transmission electron microscopy (TEM) and energy spectrum analysis techniques were used to examine and analyze microstructure and corrosion behavior of the specimens.The result showed that the Al-Sn-Bi anodes with La additions revealed higher current efficiency an...     

酸性溶液除氯技术研究现状及进展

含氯的酸性溶液对冶金工业生产造成了严重的危害。烟气净化系统产生的污酸严重腐蚀金属设备和部件,使生产成本增加,生产效率降低。在锌湿法冶炼中硫酸锌电解液中的氯对锌电解过程造成影响,加快电极腐蚀,降低电解锌的产品质量,经济效益下降,严重危害生产,因此酸性溶液中氯离子的去除研究具有重要意义。本文分析了污酸和硫酸锌电解液2种典型的高含氯量的酸性溶液的产生和危害,总结了国内外已有的除氯技术及研究现状,指出酸性溶液除氯技术的主要发展方向。