掺有磷渣的水泥基材料研究现状与分析

简介了磷渣的组成、结构与活性,分析了影响磷渣活性的主要影响因素;综述了磷渣作为辅助性胶凝材料对水泥基材料凝结时间、水化热、结构变化、强度、干燥收缩和耐久性等的影响,分析了磷渣在水泥基材料中应用存在的主要问题,并提出了一些改善措施和解决思路。加强磷渣在水泥基材料中的应用基础研究,对提高磷渣在水基材料中的利用率和减少环境污染有着重要意义。     

垃圾焚烧炉渣-粉煤灰复合水泥的性能研究

研究了垃圾焚烧炉渣及粉煤灰单掺和复掺时硬化水泥浆体的力学性能和水化机理,比较了两者的活性,探讨了两者作为辅助性胶凝材料利用的可行性.研究表明:掺有垃圾焚烧炉渣及粉煤友的复合水泥,其强度均有不同程度的下降,它们的掺入在一定程度上延缓了水泥的水化过程,且垃圾焚烧炉渣的水化反应活性稍高于粉煤灰;掺垃圾焚烧炉渣及粉煤灰的复合水泥中重金属离子浸出量小,在等掺20%的条件下,浸出量远低于国家标准,说明在一定的情况下,焚烧炉渣及粉煤灰作为辅助性胶凝材料使用是安全的.     

A discussion on improving hydration activity of steel slag by altering its mineral compositions

This study aims to investigate the ways to improve the cementitious properties of steel slag. The results show that the cementitious phase of steel slag is composed of silicate and aluminate, but the large particles of these phases make a very small contribution to the cementitious properties of steel slag. RO phase (CaO-FeO-MnO-MgO solid solution), Fe(3)O(4), C(2)F and f-CaO make no contribution to the cementitious properties of steel slag. A new kind of steel slag with more cementitious phase and less RO phase can be obtained by removing some large particles. This new steel slag possesses better cementitious properties than the original steel slag. The large particles can be used as fine aggregates for concrete. Adding regulating agent high in CaO and SiO(2) during manufacturing process of steel slag to increase the cementitious phase to inert phase ratio is another way to improve its cementitious properties. The regulating agent should be selected to adapt to the specific steel slag and the alkalinity should be increased as high as possible on the premise that the f-CaO content does not increase. The cooling rate should be enhanced to improve the hydration activity of the cementitious phase at the early ages and the grindability of steel slag.     

A multi-phase kinetic model to simulate hydration of slag–cement blends

Ground granulated blast furnace slag, which shows cementitious behavior (latent hydraulic activity) and pozzolanic characteristics (reaction with lime), has been widely used as a mineral admixture in normal and high strength concretes. Hydration of slag–blended cement is much more complex than that of ordinary Portland cement because of the mutual interactions between the cement hydration and the slag reaction. This paper presents a kinetic hydration model for cement–slag blends. The proposed model analyzes the slag reaction separate from cement hydration by considering the production of calcium hydroxide in cement hydration and its consumption in slag reactions. The amount of free water and the amount of calcium hydroxide left in the system were adopted as the control indicators for determining the slag reaction. Using the proposed model, the reaction ratio of slag can be evaluated as a function of curing age, considering the influences of the water to binder ratio, the slag replacement ratio and the curing temperature. Furthermore, the amount of chemically-bound water (self-cementing properties), calcium hydroxide (pozzolanic capabilities), and the heat released from hydration are evaluated by determining the contributions from both the cement hydration and the slag reaction. The evaluated results show good accordance with the experimental results.     

钢渣胶凝活性评价方法的研究进展

钢渣是炼钢时产生的工业废渣,因含有C2S、C3S等矿物相而表现出胶凝活性。钢渣利用其胶凝活性作为水泥混凝土的矿物掺合料,是其高效资源化利用的重要途径,同时也是绿色建材的发展方向。综述了钢渣胶凝活性评价方法的研究现状,包括碱度系数法、矿物相微观测试法、比强度法、活性因子法以及快速评定法,认为钢渣胶凝活性由钢渣中能够参与水化反应表现出水硬性的组分体现,并提出了钢渣胶凝活性评价的研究发展方向。     

铜渣熔融还原炼铁过程反应热力学分析

对铜渣还原炼铁过程中各元素的反应热力学及渣处于熔融状态时(FeO)组分作用浓度分别进行了理论分析。XRD分析结果显示铜渣中含铁物相主要为铁橄榄石(2FeO.SiO2)。热力学分析结果表明,铜渣中添加一定量CaO,(2FeO.SiO2)还原反应理论起始温度由1042.23K降至757.47K;渣中Mg、Al、Si和Ca 4种元素的还原反应不能发生;增加熔池中O2-浓度,Fe2+还原限度升高。FeO-SiO2-CaO三元渣系作用浓度模型计算结果显示,熔池碱度为2.0时,(FeO)组分作用浓度达到最大0.14。     

Oxidative dehydrogenation of n-butane over vanadium magnesium oxide catalysts supported on nano-structured MgO and ZrO2: effect of oxygen capacity of the catalyst

Vanadium-magnesium oxide catalysts supported on nano-structured MgO and ZrO2 (Mg3(VO4)2/MgO/ZrO2) were prepared by a wet impregnation method with a variation of Mg:Zr ratio (8:1, 4:1, 2:1, and 1:1). For comparison, Mg3(VO4)2/MgO and Mg3(VO4)2/ZrO2 catalysts were also prepared by a wet impregnation method. The prepared catalysts were applied to the oxidative dehydrogenation of n-butane in a continuous flow fixed-bed reactor. Mg3(VO4)2/MgO/ZrO2 (Mg:Zr = 4:1, 2:1, and 1:1) and Mg3(VO4)2/ZrO2 catalysts showed a stable catalytic activity during the whole reaction time, while Mg3(VO4)2/MgO/ZrO2 (8:1) and Mg3(VO4)2/MgO catalysts experienced a severe catalyst deactivation. Deactivation of Mg3(VO4)2/MgO/ZrO2 (8:1) and Mg3(VO4)2/MgO catalysts was due to their low oxygen mobility. Effect of oxygen capacity (the amount of oxygen in the catalyst involved in the reaction) of the supported Mg3(V04)2 catalysts on the catalytic performance in the oxidative dehydrogenation of n-butane was investigated. Experimental results revealed that oxygen capacity of the catalyst was closely related to the catalytic activity in the oxidative dehydrogenation of n-butane. A large oxygen capacity of the catalyst was favorable for obtaining a high catalytic activity in this reaction. Among the catalysts tested, Mg3(VO4)2/MgO/ZrO2 (4:1) catalyst with the largest oxygen capacity showed the best catalytic performance.     

锂渣粉作为辅助胶凝材料在水泥基材料中的研究进展

锂渣是生产锂盐过程中产生的工业废渣,其含有大量活性SiO_2和Al_2O_3,有作为辅助胶凝材料的应用潜力。从物理性质、化学成分与矿物组成、活性评价与活性激发等方面介绍了锂渣自身的物理化学特性和水化活性潜质。从力学性能、工作性、耐久性、水化反应与微结构四方面重点综述了锂渣粉对水泥基材料各方面性能的影响,并进行了理论分析与总结。最后指出锂渣粉用于水泥基材料需要在活性提高、高含量SO_3和多孔结构的改善及利用等方面加强研究。     

矿渣的活性激发技术

本文综述了近年来国内外关于矿渣结构的观点，矿渣的潜在活性的激发方法及其激发机理。分别介绍了矿渣的物理激发、化学激发和复合激发方法及其机理，并提出了矿渣活化技术的发展方向。     

²²⁶Ra, ²³²Th and ⁴⁰K radionuclides enhancement rate and dose assessment for residues of lignite-fired thermal power plants in Turkey

A total of 77 coal, slag and fly ash samples collected from six thermal power plants were measured by gamma-ray spectrometry. The average (226)Ra activity concentrations in coal, slag and fly ash were measured as 199.8±16.7, 380.3±21.8 and 431.5±29.0 Bq kg(-1), respectively. The average (232)Th activity concentrations in coal, slag and fly ash were measured as 32.0±2.4, 74.0±9.0 and 87.3±9.8 Bq kg(-1), respectively. The average (40)K activity concentrations in coal, slag and fly ash were found to be 152.8±12.1, 401.3±25.0 and 439.0±30.2 Bq kg(-1), respectively. The radium equivalent activities of samples varied from 147.6±8.5 to 1077.4±53.3 Bq kg(-1). The gamma and alpha index of one thermal power plant's fly ash were calculated to be 3.5 and 5 times higher than that of the reference values. The gamma absorbed dose rates were found to be higher than that of the average Earth's crust. The annual effective dose of residues measured in four thermal power plants were calculated higher than that of the permitted dose rate for public, i.e. 1 mSv y(-1).     

铜渣粉作为混凝土掺合料的研究进展

铜渣是铜冶炼和精炼过程的副产物,以每产1 t铜副产2.2 t铜渣计算,2017年全球铜渣排放量达到了5 170万t。但目前的铜渣处理仍以堆放为主,不仅占用了大量土地,重金属成分对堆放地也造成了严重的环境污染。铜渣,特别是水淬铜渣中含有较多的玻璃体,用作混凝土掺合料可以替代粉煤灰和矿渣,解决某些地区掺合料紧缺的状况。本文归纳总结了铜渣粉对混凝土工作性、力学性能和耐久性的影响,分析了铜渣作为掺合料使用时的环境安全性,提出了铜渣作为掺合料使用应注意的问题,为铜渣粉在混凝土行业中规模化应用提供了参考。 近年的研究成果表明,水淬铜渣中的玻璃体含量高、活性更好,而缓冷铜渣的玻璃体含量虽低,但仍有一定的活性。由于存在活性低和重金属成分高的问题,铜渣粉对混凝土工作性、力学性能和耐久性的影响比矿渣、粉煤灰等常见掺合料复杂得多,阻碍了铜渣粉作为掺合料在混凝土中的应用。 虽然存在不同观点,但多数研究成果表明铜渣粉可起到降低放热量、改善工作性及减少用水量的作用,同时也会产生泌水率增加的问题。由于活性偏低、重金属成分较高,铜渣粉的缓凝作用明显,不过大掺量使用所引起的凝结时间延长问题在多数研究中是可控的。铜渣粉导致混凝土早期强度不足,可通过添加激发剂、提高细度、降低水灰比等方式予以缓解和控制。铜渣粉对混凝土强度的负面影响会随龄期延长逐渐减轻,甚至在一段时间后对强度有利。此外,铜渣粉还能提高混凝土弹性模量并减少收缩,对抗断裂性能也无明显不利影响。但以不同指标评价混凝土脆性时,铜渣粉的作用还存在较大的争议。由于可促使毛细孔隙等有害孔隙数量减少,铜渣粉可使混凝土的吸水速率和吸水量降低,从而使耐久性等级有所改善。除优化孔隙结构外,铜渣粉与Ca(OH)₂反应生成C-S-H凝胶,可改善过渡区,提高混凝土抗碳化、抗氯离子渗透性和抗硫酸盐侵蚀的能力。     

镍渣机械力化学效应及其对反应活性的影响

为提高镍渣的反应活性,根据机械力化学原理,采用高能球磨技术处理镍渣并采取蒸压工艺制备镍渣制品.通过粒径分析、X射线分析以及扫描电镜分析等手段研究不同高能球磨时间下镍渣的粒径、结构和形貌变化以及镍渣的反应活性变化.结果表明:高能球磨可以进一步细化镍渣,使大颗粒块状粉体破裂、表面粗糙化并提高镍渣的反应活性,长时间球磨可使水化样品诱导期和加速期两个阶段的水化放热量显著增大;高能球磨4 h时镍渣蒸压试块的强度最大,可达24.4 MPa,是未高能球磨时的4.5倍,球磨4 h后蒸压试块水化产物的X射线谱图中出现了硬硅钙石、托勃莫来石和镁水化物等衍射峰.     

Synthesis of zeolite from steel slag and its application as a support of nano-sized TiO2 photocatalyst

Steel slag, commercial waste material containing silica and alumina which are the chemical components elements of zeolite, was used as a source for synthesis of FAU zeolite (Y-zeolite, X-zeolite). Through acid-treatment to remove CaO species from steel slag and hydrothermal treatment, well-crystallized Na type FAU zeolite was obtained. Furthermore the synthesized FAU zeolite was applied as a support of photocatalyst. It was found that hydrophobic surface property of zeolite enhances photocatalytic activity for decomposition of organic pollutants and the zeolite synthesized from steel slag would be applicable as promising support of TiO₂ photocatalyst.     

矿渣对道路混凝土表面透气和吸水性影响

研究不同掺量的矿渣对硅酸盐水泥混凝土表面透气和吸水性能的影响规律,并对其作用机理进行探讨。利用X射线衍射(XRD)、扫描电镜(SEM)和孔隙分析(MIP),对水化生成物、混凝土微观结构和孔结构及其孔分布进行分析。结果表明:添加矿渣可以改善混凝土的表面透气和吸水性能。掺加15%矿渣对改善混凝土表面透气和吸水效果较显著,其透气和吸水系数分别为0.035和0.8,均小于基准混凝土。这是由于矿渣具有微集料效应和潜在水化活性造成的。随着矿渣掺量的增加,混凝土表面的透气和吸水性能随之降低。     

Activity of MnO in Blast Furnace-type Slags

The activity of MnO in blast furnace-typeslags CaO-SiO_2,CaO-SiO_2-Al_2O_3 andCaO-SiO_2-Al_2O_3-MgO at 1500℃ has been measuredin a graphite crucible with Ag and Sn as solventmetals.The agreement between the values ofγMnO obtained from the experimental resultsusing Ag and Sn separately as the solvent metalis excellent.The major errors in the previousstudies have proved to be the failure to takeinto account the exchange reactions involvingSi and Mn and insufficient time for theestablishment of equilibrium between slag andsolvent metal.A new method is suggested for determiningthe activities of elements in metallic solutions.The method involves the separate equilibrationof two metallic alloys,one of which containsthe component of interest at a known activity,with a single slag.     

二氧化钒的制备及应用研究

文章介绍了VO2的晶体结构及在智能温控材料方面的应用,综述了掺杂对VO2相变温度的调控和作为光学减反膜对可见光透过率的调控,分析了掺杂离子的性质、种类对VO2相变温度的影响,并对VO2的制备方法及其超细粉体的研究进展进行了总结。     

硫酸铁铵滴定法测定高钛型高炉渣中的钛

针对高炉渣反应活性差、熔样困难等特点,采用将炉渣粒度球磨至120目以下,硼酸和碳酸钠(2+1)作熔剂,900℃下熔融20 min,在瓷坩埚中铺垫石墨的方式来代替铂坩埚熔融样品,然后用硫酸(φ=10%)加热浸取熔块,铝还原Fe3+消除干扰,最后用硫酸铁铵滴定法测定钛含量。该方法用于高炉渣中钛的测定,相对标准偏差RSD(n=5)为0.41%~0.75%,加料回收率为98.6%~101.5%,能满足测定要求。     

KHM170型卧辊磨制备钢渣超细粉工业试验研究

基于KHM170型卧辊磨的钢渣超细粉制备终粉磨工业试验系统,在给定钢渣粉、矿渣粉、水泥熟料粉的质量和粒度范围内,进行用钢渣粉部分代替矿渣粉制作水泥混凝土的强度试验。结果表明,KHM卧辊磨终粉磨系统可以实现钢渣超细粉终粉磨,可用于以热焖渣、滚筒渣为原料制备钢渣微粉的工业化生产;矿渣粉中掺加质量分数不超过30%的钢渣粉,且在满足钢渣粉比表面积大于矿渣粉比表面积和水泥熟料粉比表面积时,可以作为优选的混合材料大量用于混凝土。     

养护方式对磷渣加气混凝土性能的影响

利用磷渣的潜在活性,研制了以磷渣为原材料的加气混凝土。研究了标准养护和蒸压养护两种养护方式对磷渣加气混凝土体积密度、抗压强度、干燥收缩、抗冻性和导热系数等性能的影响。结果表明,与标准养护相比,蒸压养护可以降低磷渣加气混凝土的体积密度、干燥收缩值和导热系数,提高加气混凝土的抗冻性能。     

TaOx薄膜在VOx薄膜离子注入/抽出性能研究中的应用

利用在可见光谱具有高透射比的TaOx离子导体薄膜作为保护层 ,研究了与水溶液发生化学反应的VOx薄膜的电化学性能及相应的可见光透射性能和色度变化。厚 10 0nm的TaOx薄膜即可达到对VOx薄膜的保护 ,避免水溶液对VOx薄膜的溶蚀 ,同时又不影响离子对VOx薄膜的注入 /抽出