土酸溶液中铝的缓蚀剂的研究
发布时间：2018-12-07 07:51
【摘要】：铝是生产生活中常用的金属之一,具有硬度大,机械强度好,易塑性等优良性能,常用于制造罐体、反应釜以及其他部件。铝部件在使用过程中,内壁会因为不同的原因产生积垢,积垢易导致设备工作效率降低及安全系数下降等危害。采用盐酸、硫酸、氢氟酸等对铝部件进行酸洗可清除积垢。酸洗液除垢的同时会使铝发生腐蚀,而添加缓蚀剂可有效抑制酸洗中对铝的腐蚀。土酸兼具盐酸和氢氟酸的优点,但土酸中铝缓蚀剂的研究较少,本文对5%土酸中铝的缓蚀剂进行研究。首先通过失重法,测试出添加不同试剂时5%土酸中铝的腐蚀速率,并计算各试剂的缓蚀率。选出对5%土酸中的铝具有较好缓蚀效果的三种试剂:三聚磷酸钠(STP)、溴代十六烷基吡啶(CPB)和糠醛,并求算出对这三种试剂在铝表面的吸附热力学数据。三种试剂最佳用量分别为1g·dm-3、1g·dm-3、4g·dm-3;三者在铝表面均符合Langmuir吸附,吸附是放热过程,随温度升高,熵值减小,自由能减小,分子吸附能力减弱,缓蚀效率降低。动电位极化曲线研究结果表明,添加三种试剂时,铝的腐蚀电位均小幅负移,阳极电流密度和阴极电流密度均降低,三者均为混合型缓蚀剂。将缓蚀效果较好的单组份试剂两两复配,得到五组具有协同作用的试剂:STP与糠醛、STP与CPB、STP与苯甲醛、STP与肉桂醛、苯甲醛与1227。利用失重法研究五组试剂的最佳协同效果配比,结果为0.14:0.06、0.12:0.08、0.10:0.10、0.16:0.04、0.16:0.04。动电位极化曲线研究表明五组协同型缓蚀剂均为混合型缓蚀剂。虽然协同型缓蚀剂效果优于单组份缓蚀剂,但是依然没有达到最佳的缓蚀效果。将多种试剂进行复配,研制出由一种无机盐、一种含钒配合物及一种有机物组成的低毒的复合缓蚀剂J-HM。J-HM各成分间最佳配比为:无机盐0.8g·dm-3、有机物1.2 g·dm-3、含钒配合物1.0 g·dm-3。通过失重法和动电位极化曲线法考察J-HM对5%土酸中铝的缓蚀性能。结果表明:加入J-HM后,铝的腐蚀速率最低为0.83 g·m-2·h-1;J-HM缓蚀率最高可达到99.03%;J-HM最佳使用浓度为2 g·dm-3。土酸浓度小于6%,20 h之内,使用温度在50℃以内时缓蚀效果优良。动电位极化曲线测试结果表明J-HM为混合型缓蚀剂。综上所述,J-HM是5%土酸中铝的环境友好型高效复合缓蚀剂。
[Abstract]:Aluminum is one of the commonly used metals in production and life. It has many excellent properties, such as high hardness, good mechanical strength, easy plasticity, etc. It is often used in the manufacture of tank, reactor and other parts. In the process of using aluminum components, the inner wall will cause fouling due to different reasons, which will lead to the decrease of working efficiency and safety factor of the equipment. Using hydrochloric acid, sulfuric acid, hydrofluoric acid to pickle aluminum parts can remove dirt. The addition of corrosion inhibitor can effectively inhibit the corrosion of aluminum in pickling. Soil acid has the advantages of hydrochloric acid and hydrofluoric acid, but there are few studies on aluminum corrosion inhibitor in earic acid. In this paper, the corrosion inhibitor of aluminum in 5% earic acid is studied. Firstly, the corrosion rate of aluminum in 5% earic acid with different reagents was measured by weightlessness method, and the corrosion inhibition rate of each reagent was calculated. Three reagents, sodium tripolyphosphate (STP), hexadecylpyridine (CPB) and furfural (furfural), which have better corrosion inhibition effect on aluminum in 5% earic acid, were selected, and the adsorption thermodynamic data of the three reagents on aluminum surface were calculated. The optimum dosage of the three reagents is 1 g dm-3,1g dm-3,4g dm-3;. The adsorption is an exothermic process, and with the increase of temperature, the entropy value decreases, the free energy decreases, the molecular adsorption capacity weakens and the corrosion inhibition efficiency decreases. The results of potentiodynamic polarization curves showed that the corrosion potential of aluminum decreased slightly and the anode current density and cathode current density decreased when the three reagents were added. All of them were mixed corrosion inhibitors. Five synergistic reagents, STP and furfural, STP and CPB,STP and benzaldehyde, STP and cinnamaldehyde, benzaldehyde and benzaldehyde were obtained. The optimum synergistic effect ratio of five groups of reagents was studied by weightlessness method. The results showed that 0.14: 0.06 0. 12: 0. 12: 0. 10: 0. 10: 0. 16: 0. 16: 0.04 and 0. 16: 0.04. The potentiodynamic polarization curves showed that all the five synergistic inhibitors were mixed inhibitors. Although the synergistic corrosion inhibitor is superior to one component corrosion inhibitor, it still has not achieved the best corrosion inhibition effect. An inorganic salt, a vanadium complex and an organic compound inhibitor, J-HM.J-HM, which is composed of a inorganic salt, a vanadium complex and an organic compound, were prepared by blending several kinds of reagents. The optimum ratio of each component is as follows: inorganic salt 0.8g dm-3,. Organic 1. 2 g dm-3, vanadium complex 1. 0 g dm-3. The corrosion inhibition of aluminum in 5% earic acid by J-HM was investigated by weightlessness and potentiodynamic polarization curves. The results showed that the lowest corrosion rate of aluminum was 0.83 g m-2 h-1 + J-HM with the addition of J-HM. The highest corrosion inhibition rate of J-HM was 99.03g / h ~ (-1) J-HM. The optimum concentration of J-HM was 2 g / dm-3.. The corrosion inhibition effect is good when the concentration of earic acid is less than 6 and the temperature is less than 50 鈩，
本文编号：2366857
[Abstract]:Aluminum is one of the commonly used metals in production and life. It has many excellent properties, such as high hardness, good mechanical strength, easy plasticity, etc. It is often used in the manufacture of tank, reactor and other parts. In the process of using aluminum components, the inner wall will cause fouling due to different reasons, which will lead to the decrease of working efficiency and safety factor of the equipment. Using hydrochloric acid, sulfuric acid, hydrofluoric acid to pickle aluminum parts can remove dirt. The addition of corrosion inhibitor can effectively inhibit the corrosion of aluminum in pickling. Soil acid has the advantages of hydrochloric acid and hydrofluoric acid, but there are few studies on aluminum corrosion inhibitor in earic acid. In this paper, the corrosion inhibitor of aluminum in 5% earic acid is studied. Firstly, the corrosion rate of aluminum in 5% earic acid with different reagents was measured by weightlessness method, and the corrosion inhibition rate of each reagent was calculated. Three reagents, sodium tripolyphosphate (STP), hexadecylpyridine (CPB) and furfural (furfural), which have better corrosion inhibition effect on aluminum in 5% earic acid, were selected, and the adsorption thermodynamic data of the three reagents on aluminum surface were calculated. The optimum dosage of the three reagents is 1 g dm-3,1g dm-3,4g dm-3;. The adsorption is an exothermic process, and with the increase of temperature, the entropy value decreases, the free energy decreases, the molecular adsorption capacity weakens and the corrosion inhibition efficiency decreases. The results of potentiodynamic polarization curves showed that the corrosion potential of aluminum decreased slightly and the anode current density and cathode current density decreased when the three reagents were added. All of them were mixed corrosion inhibitors. Five synergistic reagents, STP and furfural, STP and CPB,STP and benzaldehyde, STP and cinnamaldehyde, benzaldehyde and benzaldehyde were obtained. The optimum synergistic effect ratio of five groups of reagents was studied by weightlessness method. The results showed that 0.14: 0.06 0. 12: 0. 12: 0. 10: 0. 10: 0. 16: 0. 16: 0.04 and 0. 16: 0.04. The potentiodynamic polarization curves showed that all the five synergistic inhibitors were mixed inhibitors. Although the synergistic corrosion inhibitor is superior to one component corrosion inhibitor, it still has not achieved the best corrosion inhibition effect. An inorganic salt, a vanadium complex and an organic compound inhibitor, J-HM.J-HM, which is composed of a inorganic salt, a vanadium complex and an organic compound, were prepared by blending several kinds of reagents. The optimum ratio of each component is as follows: inorganic salt 0.8g dm-3,. Organic 1. 2 g dm-3, vanadium complex 1. 0 g dm-3. The corrosion inhibition of aluminum in 5% earic acid by J-HM was investigated by weightlessness and potentiodynamic polarization curves. The results showed that the lowest corrosion rate of aluminum was 0.83 g m-2 h-1 + J-HM with the addition of J-HM. The highest corrosion inhibition rate of J-HM was 99.03g / h ~ (-1) J-HM. The optimum concentration of J-HM was 2 g / dm-3.. The corrosion inhibition effect is good when the concentration of earic acid is less than 6 and the temperature is less than 50 鈩，
本文编号：2366857
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