EFFECT OF CERTAIN SURFACTANTS ON THE LEACHING AND PRECIPITATION PROCESSES IN ZINC FERRITE RESIDUE TREATMENT

The effect of a surfactant mixture of nonylphenolpolyethylene glycol (D1), dinaphthylmethane-4,4′-disulphonic acid (D2), and polyethylene glycol with molecular weight 400 (D3) on the dissolution of zinc and metal impurities present in zinc ferrite residue in dilute sulfuric acid (160 g L^?1 H₂SO₄) as well as on both jarosite and goethite precipitation was studied at 90°C. The following influences of the surfactant mixture (D1 + D2 + D3), determined by comparing the results obtained in the presence and absence of surfactants, were found. Adsorption of surfactants on zinc ferrite residue surface decreases the dissolution of zinc and metal impurities (Fe, Cu, Cd, As, Sb, and Co). Their extraction efficiencies at the end of the super hot leaching process carried out with surfactants are 4.85–6.29% lower than without them. The formation of a sulfur “sponge” layer on the surface of liquor during the dissolution of ZnS present in zinc ferrite residue is hindered by the surfactants due to their effect as wetting agents and sulfur dispersants. The presence of surfactants reduces the amount of zinc and metal impurities (Fe, Cu, Cd, and As) remaining in the solution after jarosite or goethite precipitation by 5.33–5.86% or 8.03–9.93%, respectively. The volume of jarosite and goethite precipitates increases in the presence of surfactants due to their effect as wetting and flocculation agents. On the other hand, D1 and D3 act as complexing agents. The abovementioned effects of surfactants improve the sorption capacity of both jarosite and goethite, thus ensuring better purification of zinc sulphate solutions, but hindering zinc leaching.     

添加B对包渗法制备MoSi2涂层显微组织及静态抗氧化性能的影响

采用包渗法在Mo基体表面制备了B强化的MoSi2涂层,研究了涂层的显微结构、元素分布、相组成以及静态高温抗氧化性能。结果表明:涂层与基体之间通过扩散形成牢固的冶金结合,涂层整体厚度为80～120μm,共由三层组成。涂层中B元素沿晶界扩散富集引起的晶格畸变,使得Si在MoSi2中的扩散系数减小,导致B强化MoSi2涂层中间层厚度相对纯MoSi2涂层中间层厚度减小,但涂层整体厚度增大。经1200℃静态氧化2h后,B强化的Mo-Si2涂层失重为0.6mg/cm2,大大小于纯MoSi2涂层失重量(1.3mg/cm2),表面生成一层致密的SiO2为主体的氧化膜,阻止了涂层的进一步氧化。     

不同表面活性剂对硅油基磁流体性能的影响

本文采用化学共沉淀法制备Fe3O4纳米颗粒,以有机硅油VPO705为基体,分别以乳化剂OP-7、油酸、月桂酸和肉豆蔻酸为表面活性剂制备磁流体;通过VSM、TEM、FT-IR等对磁流体进行了表征,测试结果表明:以乳化剂OP-7作为表面活性剂制备的磁流体,其磁性颗粒大小均匀,约为10nm左右;饱和磁化强度为50.63A.m2.kg-1,并且有良好的磁响应性,在四种不同表面活性剂磁流体中磁性能最好;FT-IR结果显示四种表面活性剂都在Fe3O4纳米颗粒表面吸附上,修饰成功;热稳定性测试显示了以经乳化剂OP-7修饰的磁流体,经70℃30天的测试,其稳定性良好,没有沉降现象发生,其耐高温性明显高于其他三种磁流体。     

中国电炉炼钢粉尘处理现状

本文对中国目前电炉炼钢粉尘及其处理现状进行了综述.我国电炉炼钢粉尘产量大、回收价值高,但目前我国的电弧炉炼钢粉尘大部分被堆积填埋,只有小部分被回收处理,转底炉是我国最常用的处理电炉炼钢粉尘的方法.另外,还有一些电炉炼钢粉尘技术尚处于实验室研究阶段,这些新技术将成为我国今后电炉炼钢粉尘处理的发展方向.     

开辟除尘灰利用和环保新途径

介绍了首钢矿业公司烧结厂与中国冶金矿业总公司北京金发工贸公司、北京科技大学联合研究科学回收利用除尘灰资源的新工艺,效益颇佳,具有广泛的推广价值.     

钢铁企业粉尘的综合处理与利用

冶金粉尘是可利用的资源，通过建设集中回收处理站将企业内部产生的干粉尘混合造球，污泥调整浓度后作为一混加水，加入混合料中用于烧结，可节约开支，降低成本，改善环境。     

钢包吹氩与包衬耐火材料对钢中夹杂物的影响

通过非水溶液电解、扫描电镜、图像仪等手段,研究钢包吹氩与耐火材料对钢中夹杂物的影响。找出了夹杂物数量、尺寸、组成、分布和类型在不同工序中的变化规律,提出了改善钢的洁净度的建议。     

金银火法冶炼烟尘还原熔炼试验研究

采用单因素试验法考察了试剂加入量、造渣时间和搅拌强度对还原过程的影响。确定了最佳工艺参数：即烟尘：粉煤：纯碱=100：（18-20）：（8-10），搅拌强度40min／次，造渣时间240～270min。在此条件下，金属锑直收率为85．48％，粗锑含锑92．39％。生产实践表明。所产粗锑完全满足电解精炼要求，可以替代精锑应用于粗铅火法初步精炼工序中。     

镍铜总量对液相烧结钼基合金性能的影响

研究了镍铜总量对液相烧结Mo-W-Ni-Cu合金性能的影响,结果发现,在镍铜比一定时,随镍铜总量的增加,烧结温度下降;抗拉强度σ_b先是急剧地上升,上升到最大值1100 MPa后缓慢地下降;烧结硬度在镍铜总量不超过6％时保持最高值HB 370左右,超过6％后硬度下降;晶粒则随镍铜总量增加而细化。     

钛处理对钢中夹杂物形态和分布影响的实验研究

在实验室条件下,利用金相显微镜和扫描电镜,对加钛后的钢水样进行了观察研究,并分析加钛前后钢中夹杂物在形貌、组成、尺寸和粒度分布等各方面发生的变化,以及加钛对钢中夹杂物形态和分布的影响规律,结果表明,加钛处理可使钢中夹杂物的粒度变小、分布更趋弥散,有利于改善钢的组织和性能。     

铁合金行业无组织烟粉尘排放的治理

结合铁合金生产企业的竣工环境保护验收监测数据,分析了铁合金生产过程中在加料、冶炼、出铁等环节以及原料场的颗粒物无组织排放的防治现状,从原料堆场的防扬尘措施、物料转运及冶炼无组织集烟措施等方面提出了铁合金生产过程中烟粉尘控制的原则性措施.对铁合金行业无组织烟尘排放治理有一定的指导意义.     

锰硅锰铁合金中夹杂碳化硅对检测分析影响的探讨

锰硅、锰铁合金中有部分样品夹杂有碳化硅,在化学分析锰硅合金中硅时,采用氟硅酸钾滴定法和钼蓝光度法时因碳化硅未被分解,从而导致结果偏低,锰铁合金一般采用高氯酸重量法,碳化硅被分解,分析结果较为准确。在荧光粉末压片法分析时,由于碳化硅的激发增强效应,致使硅检测结果偏高。本文通过实验确定了修正方法,消除了夹杂碳化硅对硅元素的影响,确保了检测分析结果准确。     

微量元素铋,锑对大断面球铁件石墨形态的影响

本实验使用光学显微镜和分析电检查了石墨形态。实验结果表明，在含稀土的球铁中加入铋，锑可以使石墨政治协商会议数量显著增加，并使石墨球更加细小、圆整、消除了大断面球铁中的畸变石墨。另外，检查结果发现，石墨核心主要是由稀土与铋、锑、铝等元素组成的复杂化合物。因此，可以认为导致大断面球铁石墨畸变的根本原因是缺乏足够的稳定结晶核心。     

高炉内热震的监测与判别及其对炉墙侵蚀的影响

引出热震及其热震强度和热震指数等概念,试图定量描述高炉中、上部炉墙内的温度急剧变化。通过实测数据的分析,证明热震指数与炉墙侵蚀速度间呈线性关系。为生产高炉控制热应力产生的炉衬破损速度提供了检测方法和相应的理论依据。     

钢中残余铜的危害及其对策

叙述了钢中残余铜对产品质量的影响，提出了解决这一问题的具体措施。     

INVESTIGATIONS ON THE MECHANISMS OF SULFURIC ACID LEACHING OF CHALCOPYRITE IN THE PRESENCE OF HYDROGEN PEROXIDE

The sulfuric acid leaching behavior of chalcopyrite in the presence of hydrogen peroxide was studied at 25°C using electrochemical techniques. The effects of increasing the concentrations of hydrogen peroxide up to 3 M on chalcopyrite dissolution were carried out in shake flasks prior to electrochemical studies. Electrochemical investigations were carried out on particulates electrode made from powdered chalcopyrite samples using potentiodynamic and chronoamperometric techniques. Increasing the concentrations of hydrogen peroxide considerably accelerated the leaching of both copper and iron. Morphologies of the leached residues examined by scanning electron microscope revealed similar products on the surfaces of chalcopyrite for all the conditions of leaching. A reduction in sizes of the particles, which increase the porosity of the residues, was observed at increasing concentrations of hydrogen peroxide. X-ray analysis revealed the presence of elemental sulfur in the solid residues with increasing crystallinity as the concentration of hydrogen peroxide increased. Polarization curves showed that hydrogen peroxide raised the dissolution potentials of chalcopyrite toward more noble values. The addition of hydrogen peroxide also drastically increased the dissolution currents, current densities, and dissolution rates, and reduced the passivity of chalcopyrite. Increasing the concentration of hydrogen peroxide and dissolution potential resulted in a characteristic current increase/decrease behavior of the ore. Higher dissolutions obtained at increased concentrations of hydrogen peroxide were attributed to the porous agglomerate nature of the leached residues that did not passivate the chalcopyrite surface, but aided further dissolution through electron transfer.     

对提高高碳锰铁电炉湿法除尘煤气入柜率的研究与实践

介绍了铁合金封闭电炉及除尘工艺的发展趋势,并以高碳锰铁电炉为例,通过具体工艺和操作的改进,提高了高碳锰铁电炉湿法除尘煤气的入柜率,真正实现了清洁生产。结果表明,利用高碳锰铁湿法除尘工艺,12．5MVA高碳锰铁电炉可实现每日节能17．14吨标准煤,占其电能消耗的21．8％。     

原料场抑尘技术研究与应用

针对攀枝花旱季时间长,攀钢炼铁厂原料场扬尘严重造成环境污染和物料损失的情况,在实验室和现场应用试验的基础上,对炼铁原料场实施抑尘技术。结果表明,运用此技术防尘效果好、操作简单,环境效益和经济效益显著。