锌铁及其合金镀层黑色钝化膜耐蚀性能的研究

为了提高Zn-Fe合金镀层及Zn-Fe-TiO2复合镀层的耐蚀性,采用非银盐发黑剂,结合磷化工艺,并加入适当的添加剂及辅助成膜剂,系统研究了含铁0.2%～0.8%的Zn-Fe合金镀层黑色钝化工艺,得到了最佳的镀液组成及工艺条件.采用这种钝化工艺获得的钝化膜油黑发亮,色调均匀,耐蚀性高,附着力强,耐磨性好.在最佳镀液组成及工艺条件下,对Zn镀层、Zn-Fe合金镀层及Zn-Fe-TiO2复合镀层黑色钝化膜的耐蚀性进行了研究.5%NaCl中性溶液浸泡实验表明,经黑色钝化后,Zn-Fe合金镀层及Zn-Fe-TiO2复合镀层的耐蚀性有了很大的提高.Zn-Fe合金镀层的耐蚀性是纯Zn镀层的3倍多;Zn-Fe-TiO2复合镀层的耐蚀性是Zn-Fe合金镀层的2倍左右,是纯Zn镀层的5倍左右,是一种理想的代镉镀层.     

Equilibrium of hydroxyl complex ions in Pb^2＋-H2O system

The thermodynamics equilibrium principle was used to construct the diagrams for the concentration of complex ions (pc) vs pH, the distribution ratio of lead hydroxyl complex ions (αn) vs pH, and the conditional solubility product of Pb(OH)2 vs pH in the Pb2+-H2O system. The relationship between the equilibrium concentration of each kind of lead hydroxyl complex ions in equilibrium with Pb(OH)2(s) and pH value was shown in the system. The minimum solubility of lead is at the pH value of 10.096-10.997. The distribution ratio of each kind of the lead hydroxyl complex ions is determined as a function of the pH value and the total lead concentration ([Pb]T). The diagram for the conditional solubility product, pKSP vs pH, shows that each kind of lead hydroxyl complex ions existing in the system is dependent upon an optimized pH value at the established concentration of [Pb]T, and that pKSP reaches the minimum at the pH value of 10.3-11.2. The results can provide a theoretical basis for removing lead ions from wastewater by the neutralization and hydrolyzation technology.     

Treatment of nickel-ammonia complex ion-containing ammonia nitrogen wastewater

Air stripping was adopted to treat nickel ammonia complex ion-containing wastewater in order to remove nickel and ammonia simultaneously in one technological process. The relationship among pH, the concentration of nickel ammonia complex ion and total ammonia concentration was analyzed theoretically. Influence of pH value, water temperature, airflow rate and time on air stripping was studied in detail by static experiment in laboratory. The results show that at pH 11, temperature of 60 °C and airflow rate of 0.12 m³/h, NH₃ and Ni²⁺ concentrations remained in wastewater are less than 2 and 0.2 mg/L, respectively, after blowing for 75 min, which reaches the standard of the state discharge. When the tail gas is absorbed by 0.5 mol/L H₂SO₄ in order to avoid the secondary pollution, the absorption rate can achieve 70%.     

CaSO4-Ca(OH)2-H2O体系中硫酸根的平衡浓度

测定了25℃时不同pH值下CaSO4-Ca(OH)2-H2O三元体系中SO42-的平衡浓度,考察了Na+离子的影响. 结果表明,pH值在3.0~12.0范围内SO42-平衡浓度最小,为0.01235 mol/L,基本不受pH值的影响;Na+的存在使溶液中SO42-的平衡浓度增大,且二者呈线性关系. 应用Pitzer电解质溶液理论对体系进行了活度修正,计算结果与实验测定结果基本一致. 研究结果为含SO42-工业废水处理提供了一定的理论依据.     

载银纳米TiO2抗菌竹炭的制备

以工业TiOSO4为原料,分别通过水解法和胶溶法制备载银纳米TiO2抗菌竹炭.采用XRD和SEM对样品进行了表征,研究了不同载银量、煅烧温度、TiO2/C和竹炭粒径对抗菌率的影响.结果表明,水解法制备的抗菌竹炭的抗菌效果优于胶溶法制备的抗菌竹炭,控制载银量、煅烧温度、TiO2/C、竹炭粒径分别为2%、500℃、2%、200目时,水解法制备的抗菌竹炭抗菌率最佳;控制载银量、煅烧温度、TiO2/C、竹炭粒径分别为3%、500℃、3%、200目时,胶溶法制备的抗菌竹炭抗菌率最佳.     

冶金工程专业英语教学改革与实践

专业英语重在培养学生英语应用能力和自主学习能力。基于精品示范理念,以主题模块模式为导向,以内容多元化为准则,对冶金工程专业英语教材内容进行精选与编辑。建设了科学合理的教学团队。从开放式教学模式、层次性教学模块和多样化教学方式出发,进行了教学的改革与实践。采用多样化、多途径、全方位考核方式,对教学效果达成进行了评价。改革取得了很好的教学效果,提高了学生独立思考能力、解决问题能力、主动学习能力、创造知识能力以及综合素质和竞争能力。     

高稳定性碱性硫脲体系对不同类型金矿的适应性

为考察碱性硫脲体系对不同类型金矿浸出的适应性,选用理化性质不同的6种含金物料,分析了其化学组成及矿物物相,并对其浸出行为进行了研究. 结果表明,稳定剂Na2SO3和Na2SiO3大大降低了碱性硫脲的分解率,随稳定剂浓度的增大,硫脲分解率逐渐降低;而且Na2SiO3对碱性硫脲的稳定效果明显优于Na2SO3,当Na2SiO3浓度为0.3 mol/L时,硫脲的分解率由72.5%降至33.8%. 铁氰化钾为适合碱性硫脲浸金的温和氧化剂. 碱性硫脲体系中金矿物浸出前后物相基本无变化. 所选择的金矿物中均含有大量耗碱物质,使溶液的pH值由12.5很快降至中性,但稳定剂Na2SiO3能维持体系的pH值在12左右,有利于浸出过程的进行. 碱性硫脲体系中伴生金属浸出率小于0.1%,浸金具有显著的选择性. 碱性硫脲体系适合浸出经预处理的物相主要为SiO2的氧化矿,浸金率高达82.68%,为碱性硫脲成功应用于黄金工业生产提供了一定的理论依据.