污酸废水中铜和砷的气-液梯级硫化与分离（英文）

通过气-液硫化反应初步分离污酸废水中的铜和砷,并将一级铜、砷分离渣按一定比例加入污酸原液中实现溶液中铜和渣中砷的置换分离。考察反应时间、温度和H2S用量对铜、砷去除率的影响,同时考察固液比、时间和温度对铜、砷置换反应的影响。当在50℃时加入20mmol/L的H2S时,在0.5min时间内即可使铜的去除率达到80%以上,且砷的去除率约为20%。将铜、砷一级分离渣按照10%以上的固液比例加入污酸废水中,在20℃下10min后由于铜、砷置换作用,废酸中铜和砷分离率达到99%以上。沉渣中主要物相为CuS,富集的铜渣中铜的质量分数为63.38%。     

含砷污酸资源化回收铜和砷的新工艺

以含砷污酸为原料,通过中和除杂-沉砷-洗涤-浸出-蒸发结晶-溶解制取三氧化二砷,实现含砷污酸的资源化。结果表明：将污酸中和至pH为2,使污酸的酸度降低;在中和液中加入硫酸铜,控制Cu和As的摩尔比为1.5：1,调节体系pH为8沉淀As,得到亚砷酸铜,As的沉淀率达到97.81%;通过洗涤除杂提高亚砷酸铜中As和Cu的含量;采用10%硫酸溶液,在液固比为5：1条件下浸出亚砷酸铜,所得溶液蒸发结晶得到三氧化二砷与硫酸铜的混合物;用水溶解该混合物后过滤得到硫酸铜溶液及符合 YS/T-99-1997As2O3-3号产品标准的三氧化二砷。     

冶炼烟气洗涤污酸废水气液硫化除锌

采用气液硫化法对模拟含锌污酸废水进行处理,考察pH值、H2S气体分压、反应温度、反应时间、Zn~(2+)初始浓度等条件对Zn~(2+)去除效果的影响。在单因素实验的基础上进行五因素五水平的正交实验,并对采用该工艺处理冶炼烟气洗涤污酸废水效果进行验证。研究Zn~(2+)硫化分离的热力学,及其气液反应动力学过程,并对锌沉渣进行分析与表征。结果表明:在最佳工艺条件为模拟溶液初始pH值3、反应时间80 min、温度35℃、H2S气体的体积分数为30%、Zn~(2+)初始浓度100 mg/L时,Zn~(2+)脱除率为99.54%,沉渣主要物相为ZnS,锌的质量分数达63.84%;实际污酸废水锌浓度为569和216.7 mg/L时,去除率分别达到99.79%和99.49%。     

童成业:百舸争流 奋楫者先

正童成业多次到北京,向相关部门进行汇报,并邀请生态环境部相关单位来其所在公司——河南豫光金铅集团(以下简称"公司")实地调研。2019年12月,《国家危险废物名录(修订稿)》(第二版)中,不但将铜冶炼污酸处置产生的石膏渣、中和渣移除危废名录,还将铅锌冶炼污酸处置产生的石膏渣及中和渣移除危废名录。固废属性变更后,公司铜、铅、锌冶炼污酸处置产生的数万吨石膏渣、中和渣,由危废变为一般固废,降低了经营风险,每年为公司节约危废处置费数以千万记。     

钢渣改性对污酸除砷的影响

钢渣是一种冶金工业固体废弃物,具有强碱性并富含铁氧化物,对酸性重金属废水处置有着巨大潜力,改性钢渣有望进一步提高除砷效率并应用于污酸除砷。实验研究了酸、碱、盐和热改性对钢渣理化性质和除砷效率的影响,考察了强化氧化对改性钢渣除砷性能的影响规律,分析了除砷后钢渣浸出毒性特性。结果表明:与未改性钢渣相比,改性钢渣除砷性能有所提高,其中酸改性和盐改性钢渣的除砷性能显著提高。针对含砷浓度为4200mg/L的污酸,按照固液比0.04 kg/L加入酸改性钢渣,在氧化剂作用下并在室温振荡反应120 min,处置后污酸残余砷浓度降至88.44mg/L,砷去除效率达到97.89%,除砷后钢渣浸出毒性低于危险废弃物鉴别标准《GB5085.3—2007》限值5mg/L,属于一般固体废弃物,可安全堆存。研究表明:酸改性钢渣能释放大量Ca、Fe离子,通过共沉淀和吸附的作用可将砷去除。钢渣预处理及除砷机制为钢渣两步法处置含砷污酸提供了一种思路。     

从沉钨钼后液中制备高纯铼酸铵

利用沉钨钼后液首先经氯化钾沉淀反应得到铼酸钾,其次采用离子交换法将铼酸钾溶液转为高铼酸溶液,最后经氨水中和-浓缩结晶-重结晶得到高纯铼酸铵。结果表明:向沉钨钼后液中加入KCl固体再浓缩析出KReO₄白色晶体,其主要杂质Na、Ca、Fe、Cl含量均小于1.00%,特别是W、Mo含量均小于0.10%,且Re结晶率可达94.92%～98.38%。采用动态法脱K,选用C160(H⁺型)树脂,当KReO₄溶液pH为中性,料液流速控制在2BVs·h^-1时,C160树脂对K⁺穿透容量和饱和容量分别为117.87和128.39g·L^-1,且树脂利用率达到91.81%;所得纯HReO₄溶液中K、Na、Ca、Fe、W、Mo、Mg浓度均降至0.50 mg·L^-1以下。通过添加优级纯氨水中和HReO₄溶液,控制终点pH为7～8,再经浓缩结晶+1次重结晶,所得铼酸铵纯度达到99.99%以上,其SEM形貌为树枝状。     

钴冶炼系统中P204反萃液有价金属的控电位硫化分离技术

介绍钴冶炼工艺及P204反萃液产出,总结P204反萃液处理方法的研究进展,提出有价金属的控电位选择性分离的技术。通过热力学计算并绘制Me-S-H_2O系φ-pH图,从理论上证明有价金属的控电位选择性硫化分离技术可行;分别研究了控电位硫化除铜、控电位硫化除钴与黄药除钴、控电位硫化沉锌和中和沉锰4个过程的实施效果。结果表明:该方法可以实现有价金属的分步分离且金属回收率均可达到99%以上,沉淀物硫化铜、黄原酸钴、硫化锌和碳酸锰都可以作为冶炼原料再利用,处理后液为无害溶液可直接排放。实现了P204反萃液中有价金属分步沉淀和无害化处理的双重目的。     

用升流式膨胀中和滤池处理硫酸废水

一、前言我们为某援外项目设计的酸洗车间,排出废水量为300米~3/日,含硫酸1500毫克/升,PH≈2。废水须经中和处理才能排出。欲采用升流式膨胀中和滤池,中和料为石灰石(CaCO_3)进行处理。为进一步摸索其运行规律,结合第二砂轮厂酸洗车间硫酸废水处理情况进行技术改造,即用升流式膨胀中和滤池取代现有的石灰中和处理的陈旧工艺。根据该厂酸洗车间现有条     

冶炼烟气制酸项目污染治理及环境影响

在环保治理综合利用政策背景下,烟气制酸将成为众多冶炼企业的必然选择。冶炼烟气净化制酸工艺流程主要包括净化、干吸和转化三部分。根据新疆地区实例分析可知,经过制酸后冶炼烟气含有的二氧化硫等污染物浓度大大降低,尾气可实现达标排放;烟气制酸产生的污酸等污染物采用石灰乳中和-铁盐曝气除砷-戈尔膜过滤工艺处理后达标废水可进行回用。烟气制酸本身即是污染治理项目,对其产生的污染物进行治理可进一步减轻对环境的影响。     

铁酸锌选择性硫化行为与物相转变机制

为了高效回收含铁酸锌物料中的有价金属,本研究通过硫化焙烧将铁酸锌选择性地转化为硫化锌和铁氧化物或单质铁,再通过常规选矿和湿法冶金的方法实现铁锌分离与回收。利用HSC和Factsage软件研究铁酸锌硫化反应热力学,通过硫化焙烧试验研究了不同工艺条件对铁酸锌硫化行为和物相转变机制的影响。结果表明：在高温条件下,黄铁矿分解产生的气体硫和铁酸锌发生硫化反应,温度、黄铁矿和碳用量均为铁酸锌硫化的主要影响因素,适当提高温度及增加黄铁矿和碳用量可以提高锌的硫化率,添加适量钠盐有助于铁酸锌硫化。在最佳工艺条件下,铁酸锌硫化率可达84%。经XRD和SEM分析,硫化焙烧主要产物为硫化锌和铁氧化物,人造硫化矿的晶粒较小,添加钠盐能够促进人造硫化锌晶粒的长大。     

工艺布局中的减排措施和废水回用

QPQ工艺产生的废水为碱性,铝合金阳极氧化工艺产生的废水是酸性.在工艺布局中将两者结合,可以使废水酸碱中和达到减少排放的效果.采用中和、混凝、沉淀和斜管分离的工艺流程,对废水进行深度处理后大部分回用于生产.     

Physicochemical properties of arsenic-bearing lime–ferrate sludge and its leaching behaviors

Physicochemical properties and leaching behaviors of two typical arsenic-bearing lime–ferrate sludges (ABLFS), waste acid residue (WAR) and calcium arsenate residue (CAR), are comprehensively described. The chemical composition, morphological features, phase composition and arsenic occurrence state of WAR and CAR are analyzed by ICP–AES, SEM–EDS, XRD, XPS and chemical phase analysis. The toxicity leaching test and three-stage BCR sequential extraction procedure are utilized to investigate arsenic leaching behaviors. The results show that the contents of arsenic in WAR and CAR are 2.5% and 21.2% and mainly present in the phases of arsenate and arsenic oxides dispersed uniformly or agglomerated in amorphous particles. The leaching concentrations of arsenic excess 119 and 1063 times of TCLP standard regulatory level with leaching rates of 47.66% and 50.15% for WAR and CAR, respectively. About 90% of extracted arsenic is in the form of acid soluble and reducible, which is the reason of high arsenic leaching toxicity and environmental activity of ABLFS. This research provides comprehensive information on harmless disposal of ABLFS from industrial wastewater treatment of lime–ferrate process.     

高浓度泥浆法处理矿山酸性废水机理

针对传统石灰法处理矿山酸性废水存在结垢严重和处理效果不稳定等问题,研究了高浓度泥浆法(HDS)替代工艺。结果表明,高浓度泥浆法(HDS)处理矿山酸性废水的主要机理如下:酸碱中和、金属离子沉淀及共沉淀作用;污泥回流使沉淀底泥晶体化、粗颗粒化,加快了污泥沉降和分离的速度;沉淀底泥Zeta电位提高,易于与带负电位的硫酸钙接近并附着,晶核不断长大,可显著延缓设备和管路的结垢。该技术处理矿山酸性废水效果好,出水水质稳定达到GB 8978—1996《污水综合排放标准》中二级排放标准的要求。     

冷轧厂酸洗废液处理工艺设计与实践

介绍了衡水薄板有限责任公司冷轧厂酸洗废液处理中，对废酸和废水分别采用不同的工艺方法进行处理，不仅使废酸得到回收利用、废水处理后达标排放，而且废酸处理过程中产生的FeCl2还可为企业带来可观的经济效益。     

球磨钢件表面残留锈蚀度及其对热浸镀锌漏镀的影响

目的 探究球磨前处理对钢件表面残留锈蚀度及其对热浸镀锌漏镀的影响,以期开发一种环境友好型的热浸镀锌工艺。方法 采用自主设计的高温双筒球磨机,对热浸镀锌钢件进行前处理。采用光学与电子显微镜分析球磨参数对钢件表面残留锈蚀度的影响。对球磨后的钢件进行热浸镀锌,采用扫描电镜(SEM)、X-射线衍射仪(XRD)以及高温悬滴式接触角测定仪研究钢件表面残留锈蚀产物及其对热浸镀锌漏镀的影响。结果 随着磨球粒径的增大,钢件表面残留锈蚀度a先减小后增加,磨球粒径为5 mm时达到最小值;随着滚筒转速和球磨时间的增加,钢件表面残留锈蚀度不断减少;当磨球粒径为5 mm、滚筒转速为140 r/min和球磨时间为40 min时,钢件表面残留锈蚀度a可减少到0。随着钢件表面残留锈蚀度的减小,锌液滴与基体间的接触角减小。当残留锈蚀度达到0时,接触角q =84°,锌液在基体表面均匀铺展,可避免漏镀的发生。结论 球磨除锈可以代替酸洗除锈,以减少热浸镀锌工艺对环境的污染。     

The Effects of Lime Properties on Basic Oxygen Steelmaking

Observations covering periods of good and bad conduct of heats pointed at the lime as being the cause of the metallurgical differences. A good parameter for metallurgical properties of burnt lime is its dissolving rate in water. Analysis furnishes information about the burning degree of the lime. Soft burnt lime leads to a more rapid dephosphorization and better desul-furization, as well as an easier conduct of heat with reduced slopping. Hard burnt lime has a poor solubility in slag, and pieces of lime remain undissolved. Slopping increases; the final composition of iron and slag and the final temperature are more widely scattered. Hard burnt lime is denser, the crystallite grain is larger. Annular shaft kilns with waste gas recirculation are being started up by the supplier for the production of soft burnt lime. Sizing the burnt lime by utilizing differences in density is also intended.     

Pollution-prevention analysis and the quenching of steels

With the goal of improving process efficiency and reducing risk, this article describes a pollution-prevention analysis technique that can be applied to most secondary steel heat-treating operations involving quenching. Costs, risk assessments, and pollution-prevention options are discussed, as are the effects of quenching on two subsequent processes—parts cleaning and tempering. In contrast to many process comparisons, the issues of worker exposure, material safety and toxicity, liability, waste reduction, reclamation, and disposal are emphasized.     

废液和废水中分离回收钯研究进展

贵金属钯在工业生产中应用广泛,然而资源稀缺,价格昂贵,从二次资源中回收钯变得尤为重要。而冶金、电镀、PCB制造和核工业等工业活动中产生的含钯废液和废水是钯的一种占比较大的二次资源。不同来源的含钯废液和废水在钯含量、成分组成和其他特性等方面差异较大。基于40多篇国内外相关文献的分析,总结了从废液和废水中分离回收钯的已有技术,包括沉淀/置换法、萃取法、吸附法和生物法,对各种方法的原理、应用以及优缺点进行了简要介绍。对各种方法的近期研究进展进行了对比,未来研究方向进行展望,为废液和废水中钯的分离回收提供参考。     

Corrosion behavior of aluminum alloy 5754 in cement-based matrix-simulating nuclear waste disposal conditions

Depending on the lifetime and level of radioactivity of radioactive wastes, different disposal facilities are considered. Though low- and intermediate-level short-lived waste can be disposed in surface disposal facilities, deep geological disposal is considered for high- and intermediate-level long-lived waste. In France and Belgium, long-term disposal is studied in clay host rock media. For aluminum, the disposal concept is based on encapsulation of the waste in a cement-based matrix. It is also well-known that aluminum is prone to severe corrosion in sufficiently alkaline environments leading to possible hydrogen production. To ensure the safety of the disposal facilities and the integrity of the cement capsules, the amount of aluminum that is disposed in each waste package must be specified and is limited to mitigate the level of hydrogen production by aluminum corrosion. In the present study, the corrosion resistance of an aluminum alloy (grade EN-AW-5754/H111) in two different cement matrices was studied in different configurations at room temperature. In each case, the evolution of hydrogen production was monitored to address the corrosion rate variation versus time.     

Potential Applications of Concentrated Solar Thermal Technologies in the Australian Minerals Processing and Extractive Metallurgical Industry

The Australian minerals processing and extractive metallurgy industries are responsible for about 20% of Australia’s total greenhouse gas (GHG) emissions. This article reviews the potential applications of concentrated solar thermal (CST) energy in the Australian minerals processing industry to reduce this impact. Integrating CST energy into these industries would reduce their reliance upon conventional fossil fuels and reduce GHG emissions. As CST technologies become more widely deployed and cheaper, and as fuel prices rise, CST energy will progressively become more competitive with conventional energy sources. Some of the applications identified in this article are expected to become commercially competitive provided the costs for pollution abatement and GHG mitigation are internalized. The areas of potential for CST integration identified in this study can be classed as either medium/low-temperature or high-temperature applications. The most promising medium/low-grade applications are electricity generation and low grade heating of liquids. Electricity generation with CST energy—also known as concentrated solar power—has the greatest potential to reduce GHG emissions out of all the potential applications identified because of the 24/7 dispatchability when integrated with thermal storage. High-temperature applications identified include the thermal decomposition of alumina and the calcination of limestone to lime in solar kilns, as well as the production of syngas from natural gas and carbonaceous materials for various metallurgical processes including nickel and direct reduced iron production. Hybridization and integration with thermal storage could enable CST to sustain these energy-intensive metallurgical processes continuously. High-temperature applications are the focus of this paper.