赤泥在建筑材料和复合高分子材料中的利用研究进展

赤泥是一种综合利用率较低的工业固体废弃物,其规模化、全组分、安全利用对电解铝行业的绿色发展至关重要。通过制备建材等材料制品是实现赤泥等工业固体废弃物大宗利用的关键途径。充分利用赤泥的高碱性,将赤泥与硅铝质和硫酸盐类工业固废协同使用,可制备出性能优异的水泥或地质聚合物等胶凝材料。同时利用碱性赤泥和其他工业固废的协同作用,制备出的建筑砌块和道路水稳层材料固废使用量可超过90%。利用赤泥制备陶瓷或陶粒类烧结材料是绿色、低碳、高值、大宗利用赤泥的一条有效途径。而将赤泥用作复合高分子材料的填料可以实现赤泥的高附加值利用。近年来,研究学者关于赤泥制备胶凝材料、建筑砌块、道路水稳层材料、陶粒和复合高分子材料进行了系统研究,部分成果已经实现产业化推广。本文主要介绍了赤泥制备建材制品和复合高分子材料的最新进展,并从基础理论研究、应用技术开发、政策法规引导等方面针对赤泥基材料制品的产业化推广和赤泥综合利用率的提升提出了相应建议。     

工业中脱硫技术研究现状及进展

分别介绍了工业废气脱硫在不同条件下对脱硫技术的选用,主要包括湿法脱硫、干法脱硫、加氢脱硫、非加氢脱硫,以及新兴的生物脱硫和以羰基金属作为脱硫剂的主要脱硫方法。对这些脱硫方法及其适用范围进行归纳总结,并对不同脱硫技术的脱除效率进行说明。最后展望了未来脱硫技术的发展趋势。     

火电厂锅炉水冷壁管防腐耐磨研究

循环流化床锅炉技术是近十几年来迅速发展起来的一项高效、低污染清洁燃烧技术，其主要特点在于燃料及脱硫剂经多次循环，反复地进行低温燃烧和脱硫反应，炉内湍流运动强烈，不但能达到低NOx排放、90％的脱硫效率和与煤粉炉相近的燃烧效率，而且具有燃料适应性广、负荷调节性能好、灰渣易于综合利用等优点，因此国际上这项技术在电站锅炉、工业锅炉和废弃物处理利用等领域得到广泛的商业应用，且向大型循环流化床锅炉方向发展。     

莱钢铁水喷镁脱硫工艺技术优化

简要介绍了莱钢铁水喷吹颗粒镁脱硫工艺技术改造优化过程,在改进工艺流程、优化工艺参数和优化计算机模型等方面取得了良好效果,提高了脱硫命中率,改善了脱硫效果,降低了脱硫剂消耗。     

贝壳湿法烟气脱硫可行性研究

长期作为垃圾抛弃的贝壳的化学成分与石灰石相似,其氧化钙的质量分数在54%以上,且含有利于提高脱硫效率的碱性氧化物,因此,可以考虑将贝壳用作湿法烟气脱硫的脱硫剂。基于传统的烟气脱硫方法石灰/石灰石法,钠碱法等方面考虑,分别对贝壳微粒直接进行烟气脱硫与贝壳煅烧后进行烟气脱硫进行了可行性研究分析。以贝壳作脱硫剂可同时解决抛弃的贝壳造成的环境污染问题,达到以废治污的目的。由于贝壳中钠等化合物的存在,利用贝壳进行烟气脱硫不但具有石灰/石灰石烟气脱硫法的低成本性,而且钠等化合物在浆液中的不断累积对脱硫过程还具有强化的作用,并有利于抑制设备结垢。     

KR法长寿搅拌器的研究与应用

为提高莱钢集团银山型钢炼钢厂KR法铁水炉外脱硫的功效,降低脱硫剂的消耗及操作成本,分析了KR法铁水脱硫的部分工艺参数对脱硫效率的影响,通过对KR搅拌法脱硫设备和技术的研究,采取优化搅拌器外型尺寸和结构,研制应用高性能浇注料和修补料,研究应用长寿高效的施工工艺和使用维护工艺等一系列有效措施,大大提高了KR搅拌器使用寿命,实现KR铁水脱硫预处理工艺低耗、高效运行。     

拜耳法低铁赤泥在电石渣-脱硫石膏体系中的水化硬化特性

为促进拜耳法赤泥在胶凝材料中的大宗化和高附加值利用,以山西孝义拜耳法低铁赤泥为研究对象,借助XRD、FTIR、SEM、ICP-OES等现代测试手段,研究了拜耳法赤泥在电石渣-脱硫石膏体系中的水化硬化特性。研究表明,拜耳法低铁赤泥具有潜在活性,氧化铝为其活性的最主要来源,在电石渣-脱硫石膏体系中,通过电石渣的补钙作用和脱硫石膏的促进激发作用,赤泥中的氧化铝得以有效激发,其水化产物主要为钙矾石、C-S-H凝胶、水化硫铁酸钙、钙霞石、无水芒硝和氢氧化铝。     

钒铬污泥的高效资源化利用

钒制品生产废水处置过程中会产生含钒铬污泥，其中的铬以Or（OH）3N式存在。但经长期存放Cr（OH）3易氧化为Cr^6＋，Cr^6＋为吞入性毒物，从环保角度出发，钒铬污泥不宜长期堆存，应尽早处置、利用，消除环境影响隐患。经过技术研究和反复试验和调整，我们确定了有效的克制钒、铬氧化蒸腾的含钒、铬污泥的压块制备方法，成功完成了钒铬泥球的工业应用试验。该应用研究在资源综合利用，钒制品生产领域具有先导和示范作用，为彻底解决钒制品生产废弃物钒铬泥的排放问题打下了良好基础。     

脱硫技术的六大关键问题

气体净化是化学工业生产中重要的工艺环节,特别是在化肥厂煤气粗脱硫和原料气二次脱硫及联醇、联碱等变换气脱硫及碳化原料气精脱硫技术的广泛应用,大大优化了生产工艺过程。目前,在化肥、化工行业的脱硫技术应用中,根据原料气中残留的H2S、COS、CS2的量,对精脱硫剂、水解催化剂、有机碱净化剂进行有机组合,构成各种新的工艺流程。针对脱硫技术不断创新的同时在实际生产中遇到的问题,有关专家提出,我国脱硫技术研究应注重以下六大关键问题：     

工业固废制备透水砖及其孔结构研究进展

透水砖是一种新兴的路面砖,透水砖的铺设能够加强地表与地下水的交换,缓解城市的内涝灾害.近年来,出现了大量关于透水砖的制备及其使用特性等的相关研究.另一方面,随着工业化的不断发展,产生了大量的工业固体废弃物,如果处置不当,这些废弃物的堆存不仅占据大量宝贵的土地资源,还会给当地的土壤、大气及水环境带来极大的危害.而工业固废中包含大量的SiO2、Al2 O3等无机非金属氧化物,这些非金属氧化物是砖体制备中所常见的成分.因而,将工业固废经过处理后生产透水砖,既能减轻工业固废对环境的危害,又能节约透水砖的生产成本,能够带来环保及经济双重效益.目前已有大量利用工业固废制备环保透水砖的研究,但是由于工业固废种类繁多,特性不一,导致相关研究较为分散,亟需对这些研究的反应原理进行归纳总结,以便后续研究的深入进行.本文在阅读国内外有关工业固废制备环保透水砖的论文的基础上,从利用工业固废制备透水砖的原料特性、生产工艺、反应机理以及常用的表征方法等方面出发,总结了工业固废制备透水砖的研究进展.透水砖的孔隙结构是影响透水砖强度及透水性的重要因素,通过对透水砖孔隙结构的研究,可以从原理上为透水砖的生产提供依据.因而,本文重点对透水砖的孔隙结构的分布类型、形成机理、表征方法及在孔结构研究基础上进一步利用数值模拟方法研究透水砖的渗透性的数值模拟方法进行了归纳与总结.最后,基于目前工业固废制备环保透水砖及其孔结构的研究现状,总结了该领域的研究重点及发展前景.     

工业固体废弃物资源综合利用技术现状

工业固废的综合利用已经成为建设资源节约型、环境友好型社会的重要措施。详细介绍了近几年来我国工业固废产生和处理的总体情况;概括与总结了粉煤灰、炉渣、尾矿、副产石膏、赤泥以及煤矸石等几种总产生量较大、品种较为集中的大宗工业固废的利用现状;同时以煤矸石为例详细介绍了其综合利用概况以及产业化情况,特别是利用其制备高性能混凝土、新型耐火材料、新型功能材料等高值产品将是未来的重要发展方向;最后,展望了我国大宗工业固废资源化利用技术的发展趋势。     

Utilization of flotation wastes of copper slag as raw material in cement production

Copper slag wastes, even if treated via processes such as flotation for metal recovery, still contain heavy metals with hazardous properties posing environmental risks for disposal. This study reports the potential use of flotation waste of a copper slag (FWCS) as iron source in the production of Portland cement clinker. The FWCS appears a suitable raw material as iron source containing >59% Fe(2)O(3) mainly in the form of fayalite (Fe(2)SiO(4)) and magnetite (Fe(3)O(4)). The clinker products obtained using the FWCS from the industrial scale trial operations over a 4-month period were characterised for the conformity of its chemical composition and the physico-mechanical performance of the resultant cement products was evaluated. The data collected for the clinker products produced using an iron ore, which is currently used as the cement raw material were also included for comparison. The results have shown that the chemical compositions of all the clinker products including those of FWCS are typical of a Portland cement clinker. The mechanical performance of the standard mortars prepared from the FWCS clinkers were found to be similar to those from the iron ore clinkers with the desired specifications for the industrial cements e.g. CEM I type cements. Furthermore, the leachability tests (TCLP and SPLP) have revealed that the mortar samples obtained from the FWCS clinkers present no environmental problems while the FWCS could act as the potential source of heavy metal contamination. These findings suggest that flotation wastes of copper slag (FWCS) can be readily utilised as cement raw material due to its availability in large quantities at low cost with the further significant benefits for waste management/environmental practices of the FWCS and the reduced production and processing costs for cement raw materials.     

Experimental Investigation of Heat Conduction in Red Mud/Epoxy and Red Mud/Polyester Composites

Aluminum is one of the most abundant elements, and its global production generates an immense amount of industrial waste, which is the red mud. Thus, it is necessary to develop technologies aimed to reusing red mud. In this context, this work aims to experimentally examine variations in the effective thermal conductivity of polymers, modified with the addition of different amounts of red mud. To accomplish this goal, composites with (5, 10, 15, 20, and 25) % w/w of red mud waste were manufactured using epoxy and unsaturated polyester resin as matrices. Effective thermal conductivities were measured and quantified. The data found experimentally showed a significant increase of the effective thermal conductivity as the concentration of red mud and temperature increase. The glass transition temperature was not significantly influenced by the red mud waste. Traditional theoretical models underestimate the effective thermal conductivity when compared to experimental data.     

Use of fly ash,phosphogypsum and red mud as a liner material for the disposal of hazardous zinc leach residue waste

Increasing amounts of residues and waste materials coming from industrial activities in different processes have become an increasingly urgent problem for the future. The release of large quantities of heavy metals into the environment has resulted in a number of environmental problems. The present study investigated the safe disposal of the zinc leach residue waste using industrial residues such as fly ash, phosphogypsum and red mud. In the study, leachability of heavy metals from the zinc leach residue has been evaluated by mine water leaching procedure (MWLP) and toxicity characteristic leaching procedure (TCLP). Zinc removal from leachate was studied using fly ash, phosphogypsum and red mud. The adsorption capacities and adsorption efficiencies were determined. The adsorption rate data was analyzed according to the pseudo-second-order kinetic, Elovich kinetic and intra-particle diffusion kinetic models. The pseudo-second-order kinetic was the best fit kinetic model for the experimental data. The results show that addition of fly ash, phosphogypsum and red mud to the zinc leach residue drastically reduces the heavy metal content in the leachate and could be used as liner materials.     

地聚合物固化/稳定有毒重金属及作用机理研究进展

地聚合物作为一种新型铝硅酸盐无机聚合物胶凝材料,特殊的水化反应机理和水化产物使其在固化/稳定有毒重金属离子领域中得到更多的研究及应用。本文主要对地聚合物反应机理、产物、结构和性能,地聚合物固化/稳定有毒重金属离子的机理以及影响地聚合物固化/稳定有毒重金属离子效果的因素这三大方面做了综述,并为尚未有效利用的工业废渣(拜耳法赤泥)制备地聚合物及其在固化/稳定有毒重金属离子方面的研究提供理论依据和思路。最后,指出在地聚合物固化/稳定有毒重金属离子研究中存在的不足以及对未来研究做出了展望。     

Glass-ceramics: Their production from wastes—A Review

Glass-ceramics are polycrystalline materials of fine microstructure that are produced by the controlled crystallisation (devitrification) of a glass. Numerous silicate based wastes, such as coal combustion ash, slag from steel production, fly ash and filter dusts from waste incinerators, mud from metal hydrometallurgy, different types of sludge as well as glass cullet or mixtures of them have been considered for the production of glass-ceramics. Developments of glass-ceramics from waste using different processing methods are described comprehensively in this review, covering R&D work carried out worldwide in the last 40 years. Properties and applications of the different glass-ceramics produced are discussed. The review reveals that considerable knowledge and expertise has been accumulated on the process of transformation of silicate waste into useful glass-ceramic products. These glass-ceramics are attractive as building materials for usage as construction and architectural components or for other specialised technical applications requiring a combination of suitable thermo-mechanical properties. Previous attempts to commercialise glass-ceramics from waste and to scale-up production for industrial exploitation are also discussed.     

Evaluation of blends bauxite-calcination-method red mud with other industrial wastes as a cementitious material: properties and hydration characteristics

Red mud is generated from alumina production, and its disposal is currently a worldwide problem. In China, large quantities of red mud derived from bauxite calcination method are being discharged annually, and its utilization has been an urgent topic. This experimental research was to evaluate the feasibility of blends red mud derived from bauxite calcination method with other industrial wastes for use as a cementitious material. The developed cementitious material containing 30% of the bauxite-calcination-method red mud possessed compressive strength properties at a level similar to normal Portland cement, in the range of 45.3-49.5 MPa. Best compressive strength values were demonstrated by the specimen RSFC2 containing 30% bauxite-calcination-method red mud, 21% blast-furnace slag, 10% fly ash, 30% clinker, 8% gypsum and 1% compound agent. The mechanical and physical properties confirm the usefulness of RSFC2. The hydration characteristics of RSFC2 were characterized by XRD, FTIR, (27)Al MAS-NMR and SEM. As predominant hydration products, ettringite and amorphous C-S-H gel are principally responsible for the strength development of RSFC2. Comparing with the traditional production for ordinary Portland cement, this green technology is easier to be implemented and energy saving. This paper provides a key solution to effectively utilize bauxite-calcination-method red mud.     

Red mud-based lithium-ion battery anode material with high electrochemical performance prepared by acid and SDS-assisted hydrothermal method

Journal of Materials Science: Materials in Electronics - In this work, we propose a method to prepare anode materials for LIBs from alumina industrial waste red mud. The dispersed red mud with a...     

Phosphate removal from wastewater using red mud

Red mud, a waste residue of alumina refinery, has been used to develop effective adsorbents to remove phosphate from aqueous solution. Acid and acid-thermal treatments were employed to treat the raw red mud. The effects of different treatment methods, pH of solution and operating temperature on adsorption have been examined in batch experiments. It was found that all activated red mud samples show higher surface area and total pore volume as well as higher adsorption capacity for phosphate removal. The red mud with HCl treatment shows the highest adsorption capacity among all the red mud samples, giving adsorption capacity of 0.58 mg P/g at pH 5.5 and 40 degrees C. The adsorption capacity of the red mud adsorbents decreases with increase of pH. At pH 2, the red mud with HCl treatment exhibits adsorption of 0.8 mg P/g while the adsorption can be lowered to 0.05 mg P/g at pH 10. However, the adsorption is improved at higher temperature by increasing 25% from 30 to 40 degrees C. The kinetic studies of phosphate adsorption onto red mud indicate that the adsorption mainly follows the parallel first-order kinetics due to the presence of two acidic phosphorus species, H(2)PO(4)(-) and HPO(4)(2-). An analysis of the adsorption data indicates that the Freundlich isotherm provides a better fitting than the Langmuir model.