冶金竖炉反应器处理垃圾焚烧飞灰工艺

摘要：当前国内的生活垃圾大部分都依靠焚烧技术处理，相应地会产生大量急需无害化处理的危险废物─垃圾焚烧飞灰，目前采用冶金方法处理垃圾焚烧飞灰是一个新的研究方向。首先对垃圾焚烧飞灰的成分进行分析，并在此基础上，对垃圾焚烧飞灰的压块制度及高温性能进行了探究。造块实验结果表明，水分配比为20%（质量分数），水泥配比为10%（质量分数），成型压力为10MPa，养护时间为48h，飞灰压块的抗压强度达到了512N；高温性能实验以及热力学软件计算结果表明，飞灰的融化温度控制在1400～1550℃，碱度控制在1.0～1.2之间时，炉渣具有较好的流动性。     

城市垃圾焚烧飞灰添加到烧结工艺的影响

垃圾焚烧飞灰为城市垃圾焚烧烟气净化系统和余热回收系统中收集而得到的残余物,其产生量约为垃圾焚烧量的3%~10%。因为飞灰中含有多种重金属和二噁英而被列为危险废物。本试验将焚烧飞灰添加到铁矿石烧结工艺中,研究了飞灰的添加对烧结工艺的影响。烧结试验结果表明,添加飞灰后,提高了残留在烧结矿中的Cl、S、K和Na等元素的含量,烧结成品率有所下降,转鼓指数略有变化;但添加飞灰后,烧结矿成品的还原强度指数、低温还原粉化指数、耐磨指数等指标有明显的提高。同时,添加飞灰烧结后,烧结尾气中的二噁英、SO₂、Cl、K、Na等元素含量也明显增加。     

添加城市垃圾焚烧飞灰对烧结矿性能的影响

通过烧结杯实验、烧结矿低温还原实验、中温还原实验和高温软熔滴落实验,研究添加城市垃圾焚烧飞灰对烧结矿强度和冶金性能的影响。结果表明,在0~5%(质量分数)的添加比例范围内,随着飞灰添加量的增加,烧结速度和烧结杯利用系数降低,烧结矿转鼓指数和成品率降低,软熔滴落性能恶化,中温还原度变化不显著,而低温还原粉化指数显著提高。矿相结构与成分分析表明,随着飞灰添加量的增加,烧结矿中铁酸钙和硅酸钙的相比例均有所升高;飞灰中含量较高的Al2O3、SiO2和Cl元素导致了烧结矿中低熔点相较早生成及生成量的增加,这是影响烧结过程、烧结矿强度和冶金性能的根本原因。     

高炉喷吹垃圾焚烧飞灰预处理工艺分析

为了解决高炉协同处置垃圾焚烧飞灰时氯负荷高的问题,以去离子水作为洗脱剂,通过考查不同水洗条件(水灰比、水洗时间、水洗温度、水洗次数)下垃圾焚烧飞灰中Cl元素和重金属元素的脱除效果,对飞灰高炉焚烧固化预处理中的工艺参数进行研究。结果表明,飞灰中Cl主要以NaCl、KCl、CaClOH的形式存在。在高炉协同处理前水洗预处理的适宜条件为水灰比为4 ml/g、水洗时间为5 min、水洗温度为25℃、水洗1次。在此条件下飞灰中Cl脱除率为86.45%、Zn脱除率为4.77%、Pb脱除率为35.65%、Cu脱除率为7.63%、Cr脱除率为9.71%。水洗后飞灰的配加比例、单位时间喷吹量、喷吹速度需按企业自身情况确定。在高炉喷煤比为139.12 kg/t(Fe)和飞灰喷吹量为喷煤量的1%条件下,由水洗后飞灰带入高炉的Cl质量为0.078 kg/t(Fe)、Zn为9.74×10^-3 kg/t(Fe)、Pb为1.53×10^-3 kg/t(Fe)、Cu为8.35×10^-4 kg/t(Fe)、Cr为9.88×10^-5 k...     

高炉喷吹垃圾焚烧飞灰预处理工艺分析

为了解决高炉协同处置垃圾焚烧飞灰时氯负荷高的问题,以去离子水作为洗脱剂,通过考查不同水洗条件(水灰比、水洗时间、水洗温度、水洗次数)下垃圾焚烧飞灰中Cl元素和重金属元素的脱除效果,对飞灰高炉焚烧固化预处理中的工艺参数进行研究。结果表明,飞灰中Cl主要以NaCl、KCl、CaClOH的形式存在。在高炉协同处理前水洗预处理的适宜条件为水灰比为4 ml/g、水洗时间为5 min、水洗温度为25 ℃、水洗1次。在此条件下飞灰中Cl脱除率为86.45%、Zn脱除率为4.77%、Pb脱除率为35.65%、Cu脱除率为7.63%、Cr脱除率为9.71%。水洗后飞灰的配加比例、单位时间喷吹量、喷吹速度需按企业自身情况确定。在高炉喷煤比为139.12 kg/t(Fe)和飞灰喷吹量为喷煤量的1%条件下,由水洗后飞灰带入高炉的Cl质量为0.078 kg/t(Fe)、Zn为9.74×10-3 kg/t(Fe)、Pb为1.53×10-3 kg/t(Fe)、Cu为8.35×10-4 kg/t(Fe)、Cr为9.88×10-5 kg/t(Fe),远低于一般高炉熔炼要求,可以满足高炉正常运行需求。     

胶结充填用冶金渣协同垃圾焚烧飞灰固镉机理

胶结充填采矿协同利用垃圾焚烧飞灰是解决飞灰日益激增的新思路,可大量资源化利用飞灰并固化其中的重金属离子.本文以矿渣-钢渣基胶凝材料(简称冶金渣胶凝材料)分别结合4种城市垃圾焚烧(MSWI)飞灰制备胶凝材料,并以全尾砂作为骨料制成胶结充填料,测定充填料试样的流动度、抗压强度以及Cd²⁺浸出质量浓度:冶金渣-垃圾焚烧飞灰基充填料试样的流动度为240~265 mm,满足矿山充填的泵送要求;28 d抗压强度均大于8.88 MPa,满足一般矿山充填1~6.5 MPa的强度要求;Cd²⁺浸出液质量浓度低于饮用水标准5 μg·L^-1的限值.通过X射线衍射(XRD)、红外光谱(IR)和热重-差示扫描量热法(TG-DSC)分析表明胶凝材料的主要水化产物组成为钙矾石、Friedel盐和C-S-H凝胶;通过X射线光电子能谱(XPS)发现Cd²⁺对Al²⁺的结合能有较大影响,钙矾石、Friedel盐可能对镉离子有固化作用.     

微波消解-电感耦合等离子体原子发射光谱法分析垃圾焚烧飞灰中重金属元素

应用微波消解和电感耦合等离子体原子发射光谱法(ICP-AES)测定垃圾焚烧飞灰中的Cd,Cr,Cu,Mn,Ni,Pb,Zn等7种重金属元素。考察了飞灰的最佳微波消解条件,样品用HNO3-HCl-HF-H3BO3混合酸经微波消解后,溶解时间由原来的3～5h缩短到20min。选择合适的分析谱线,试液直接用ICP-AES同时测定上述7种重金属元素,所得各元素的线性关系良好,相关系数均大于0.9990,方法的检出限在0.0005～0.008μg/mL之间。所建立的方法应用于垃圾焚烧飞灰中痕量重金属元素的测定,回收     

铁浴熔融分离垃圾焚烧飞灰中重金属的试验研究

焚烧是目前垃圾处理的主要方式之一,但垃圾焚烧所产生的飞灰中含有大量的重金属,如不进行妥善处理,会对环境产生破坏.本文采用铁浴熔池对垃圾焚烧飞灰中的重金属进行了熔融分离试验,结果表明,铁浴熔融分离方法可有效地对飞灰中的重金属进行处理.     

垃圾焚烧飞灰熔融无害化及资源化研究现状

垃圾焚烧飞灰因含二噁英和重金属被列为危险废物（HW18）,存在环境污染风险,2020年全国生活垃圾焚烧量高达14607.6万吨,以焚烧量5%（质量分数）计算,全国垃圾焚烧飞灰的产生量为730.4万吨。目前垃圾焚烧飞灰以固化填埋为主,占用土地资源,且堆存量与处理量严重失衡,无法实现资源化,因此垃圾焚烧飞灰的无害化及资源化已成为绿色发展的瓶颈课题。本文详细介绍了垃圾焚烧飞灰经熔融无害化及资源化的研究现状,阐述了熔融处理垃圾焚烧飞灰的重金属固化、二噁英降解机理,结合熔融形成的玻璃渣分析了制备微晶玻璃、泡沫微晶玻璃、胶凝材料的资源化技术,并指出现有玻璃化虽能固化重金属,但在后续资源化以及产品服役过程,重金属的迁移规律、浸出性需要进一步研究,为垃圾焚烧飞灰的综合利用提供了参考。      

A new technology for treating waste incineration fly ash by shaft furnace

At present,lots of municipal solid wastes(MSWs)are treated by incineration technology,which produces a large amount of fly ash that needs to be treated innocuou...     

Analysis of polychlorinated dibenzofurans (PCDFs) in fly ash from a waste incineration plant

In this study, a method for the congener-specific analysis of polychlorinated dibenzofurans (PCDFs) in fly ash from a waste incineration plant is described. This method involves extraction, column chromatography, and gas chromatographic-mass spectrometric techniques. Representative fly ash samples are obtained from the waste incinerator. The purpose of this research is to briefly present the findings as they relate to PCDFs. Analyses indicate that PCDFs are consistently found in the municipal incinerator.     

烧结过程协同处理垃圾焚烧飞灰的可行性探讨

中国生活垃圾焚烧飞灰产量逐年增长,其中含有二噁英、重金属和氯,对环境危害巨大,属典型的难处理危险废弃物,烧结工序拥有成熟的高温冶金技术和设备,具备处理垃圾焚烧飞灰的潜力。根据飞灰和烧结过程的主要特点,结合飞灰处理过程中存在的难点,探讨了添加飞灰对烧结过程的影响,飞灰中二噁英、重金属在烧结工序中的代谢过程,确定了烧结过程协同处理垃圾焚烧飞灰的可行性,为国内外飞灰处理企业和钢铁流程协同处置固体废弃物提供一定的参考。     

垃圾焚烧过程重金属的氯化转化与挥发

城市生活垃圾高温焚烧时容易导致垃圾中的某些重金属(温度超过其熔点)挥发,以及与烟气中的HCl,SO2,O2生成氯化物、硫化物和氧化物.研究分析了镉、铬、镍、铅、铜和锌等金属氯化物的形成过程及焚烧温度、气氛、水分等因素对重金属氯化物挥发过程的影响.实验结果表明:在1 000 ℃的焚烧温度下,空气气氛下重金属氯化物的挥发率低于N2惰性气氛下的挥发率,铬、镍和铜的氯化物挥发率差别较大,在5%以上,其他金属差别较小;随着垃圾焚烧温度升高,增加了重金属的挥发量;烟气中HCl的存在,也增加重金属的挥发量;增加试验样品的含水率,CuCl2和PbCl2的挥发量有微小增加,而ZnCl2的挥发量却有明显的降低.     

危险废物焚烧飞灰中重金属污染特性

以危险废物(70%工业废物+30%医疗废物)焚烧飞灰为研究对象,探讨了飞灰中重金属污染特性及其主要化学形态、浓度分布规律。初步得出以下结论：危险废物焚烧飞灰中主要污染重金属为Cd,Pb,Zn,其数量高于生活垃圾焚烧飞灰数倍,属于危险废物;飞灰中主要重金属以可溶及交换态、残留态、Fe-Mn氧化物结合态为主要化学形态,其中As,Cr,Cu比较稳定,而Cd,Pb,Zn易溶出进入环境;飞灰中Cd,Cu大体上呈易富集在小颗粒的趋势,Pb,Zn集中分布在50～125,125～250μm的两个粒级。     

P204从高铝粉煤灰硫酸浸液中萃取除铁

主要针对高铝粉煤灰酸浸液中铁铝萃取分离性能进行研究,通过模拟高铝粉煤灰酸浸液(C(Al3+)=37.1 g/L,C(Fe3+)=5.1 g/L),采用P204+260#溶剂油萃取体系,对组成液中铁铝进行萃取分离,系统研究了P204体积分数、温度、反应时间、溶液初始pH值、相比V(O):V(A)等因素对萃取和反萃的影响,...     

Relationships between dioxins in soil, air, ash, and emissions from a municipal solid waste incinerator emitting large amounts of dioxins

The Columbus Municipal Waste-to-Energy (Columbus WTE) facility in Columbus, Ohio, began operation in June, 1983 and ceased operation in December, 1994. During its operation, it was estimated to have released nearly 1,000 grams of dioxin Toxic Equivalents (TEQs) per year. This compares to a 1994 estimate of 9,300 g TEQ/yr from all sources emitting dioxins into the air in the United States (EPA, 1994), and to total releases of dioxins near or below 1,000 grams TEQ/Yr for England (Eduljee and Keyke, 1996), Belgium (Wevers and De Fre, 1995), and West Germany (Fiedler and Hutzinger, 1992). Because of the magnitude of emissions from this single source, studies were undertaken to evaluate the impacts to air and soil near the incinerator. This paper presents analyses evaluating dioxin concentrations and profiles in four media: stack gas, ambient air within 3 km of the incinerator, soil samples up to 8 km from the incinerator, and incinerator ash. Principal findings include: 1) an "incinerator signature" profile, as defined by stack gas emissions, was found in the ash and in subsets of the air and soil matrices, 2) soil concentrations declined from directly outside the incinerator property to the city at large, 3) an urban background soil concentration of dioxin Toxic Equivalents (TEQs) was estimated at 4 pg/g, while concentrations generally within 2 km of the incinerator ranged from 4-60 pg TEQ/g, 4) an urban background air concentration was estimated at 0.05 pg TEQ/m3, while air concentrations at a specific location about 2 km in the downwind direction of the incinerator had concentrations of 0.17 and 0.35 pg TEQ/m3 during two sampling dates, 5) analysis of the soil monitoring data in combination with the stack test data suggests that less than 2% of emitted dioxins can be found in the soil near the incinerator, and 6) principal component analysis suggests that the fraction of total concentration of OCDD is the single feature explaining most of the variation of all concentration profiles. This paper discusses these and other findings, and their implications.     

基于GIS的城市生活垃圾规划管理智能决策系统的关键技术

用现代先进的信息技术对城市生活垃圾信息进行科学、高效地管理,为城市生活垃圾治理可持续发展战略决策搭建先进的技术支撑平台,是城市生活垃圾规划管理研究的重要内容.本文在城市生活垃圾规划管理的实践基础上,完成了城市生活垃圾规划管理决策系统功能模块的设计,初步构建了辅助决策系统,探讨了图文一体化技术、模型库构建、系统模型库与GIS(地理信息系统)无缝集成、基于知识的系统等关键技术的实现     

Removal of lead in APCR leachates from municipal solid waste incinerator using peat moss in a batch counter-current sorption process

Air pollution control residues (APCR) resulting from municipal solid wastes (MSW) are most often classified as hazardous waste. A treatment process employing aqueous and alkaline leaching was developed to extract Pb, the principal contaminant found in these residues. This treatment process generates highly alkaline (pH between 11.3 and 12.5) and Pb-loaded effluent. The objective of this study was to evaluate the potential of a counter-current sorption process (CCSP) for Pb using peat moss (PM) in order to treat leachates emanating from diverse types of APCR (used lime, electrofilter ash and boiler ash). Results have shown that the CCSP process diminishes the quantity of PM required to treat these effluents by a factor of 4. Thus, a concentration of 4 g PM/L is sufficient to lower the initial Pb concentration in used lime leachate from approximately 150 mg/L to less than 0.5 mg/L. By reusing treated effluent for additional leaching and sorption cycles, our research has also shown that the quantity of water consumed during the treatment process can be reduced by 50%. Lastly, considering both the low cost of acquiring PM and managing saturated adsorbents, in addition to the efficient recuperation of Pb, the CCSP process has great potential for full-scale use.     

常压富氧直接浸出炼锌废气处理方法解析

详细介绍了株冶常压富氧浸出炼锌工程的通风设计,采用洗涤器、除雾器等对浸出反应槽、浮选槽、净液工段等挥发的酸性污染物进行捕集回收利用,既满足环保排放标准要求,又减少了反应物料损失,提高了经济效益.文章比较分析了这种新的设计思路的先进性和必要性,同时介绍了废气处理系统设计计算方法以及设备的性能评价指标,为新建及改建湿法冶炼厂及相关类似工程通风设计提供参考.     

A process for the production of magnesium oxide from serpentine by sulfur dioxide leaching and solvent extraction

The applicability of sulfur dioxide leaching for the recovery of magnesium from either natural or calcined serpentine has been investigated. Factors which influence the magnesium recovery such as time, temperature and particle size have been studied, and the optimum values were determined. It has been suggested that the kinetics of the reaction are controlled by diffusion phenomena. The possibility of recovering pure magnesium sulfite from the leach solutions containing iron, nickel, calcium, etc. using the liquid-liquid extraction technique is indicated.