基于正交设计高性能钢铁渣粉的制备与性能研究

为了制备出性能优良的钢铁渣粉,试验采用L_9(3~4)正交设计,考察了矿渣粉细度、钢渣粉细度及掺量等三因素对胶砂流动度和抗压强度的影响,并进行了极差分析,方差分析及性能指标分析。基于优化结果研究了钢铁渣粉胶砂的泌水性和干缩性能,通过MIP分析了硬化水泥浆体的孔结构。结果表明:当钢铁渣粉取代水泥50%(质量分数,下同)时,三因素对不同龄期胶砂抗压强度的影响规律一致;钢渣粉细度是胶砂流动度的显著性影响因素,但对胶砂抗压强度的影响"不显著";适当降低钢渣粉掺量,提高矿渣粉细度对提高钢铁渣粉的胶凝活性有利,优化的钢铁渣粉参数为钢渣(348m~2/kg)∶矿渣(452m~2/kg)=30%∶70%;与单掺矿渣粉相比,优化的钢铁渣粉砂浆泌水率为0,4d和80d胶砂干缩率分别下降了19.71%和14.43%,同时优化了硬化水泥浆体的孔结构。     

液氨介质中多孔硅粉对钙和铕的吸附性能

通过吸附钙和铕来改变多孔硅的表面状态,以提高其发光效率。采用金属辅助化学腐蚀法制备多孔硅粉,以液氨为介质溶解金属钙和铕,使钙和铕吸附在多孔硅表面。利用扫描电子显微镜、傅里叶变换红外光谱仪、能谱仪对多孔硅粉特性以及多孔硅粉在液氨介质中对金属钙和铕的吸附性能进行表征。结果表明:金属辅助化学腐蚀硅粉表面的孔径受腐蚀液温度的影响,当腐蚀液温度为40℃时,硅表面孔径最均匀且孔径最大;在液氨介质的作用下,多孔硅粉吸附氨分子基团,形成Si—(NH2)2;多孔硅通过液氨介质能够吸附金属离子,使金属胺钙均匀沉积在多孔硅粉表面,金属胺铕非均匀沉积在多孔硅表面。     

钢渣粉-矿粉-磷渣粉三元复掺对混凝土电通量的影响

为了提高混凝土的抗氯离子侵蚀性能,通过钢渣粉-矿粉-磷渣粉三元复掺的方式制备了强度等级C40的混凝土.采用XRD、SEM和压汞法等手段研究了钢渣粉-矿粉-磷渣粉三元复掺对混凝土水化产物、微观结构和孔隙率的影响.结果表明:在等质量替代60％水泥时,当钢渣粉、 矿粉、 磷渣粉掺量比为1:1:1和1:3:2时(G20k20和...     

掺硫酸渣粉水泥砂浆的抗硫酸盐侵蚀性能

通过测定以0(参照样)、10%、20%、30%掺量的硫酸渣粉代替水泥制成的砂浆试件,在不同硫酸盐溶液环境中的抗蚀系数,并借助XRD测定水泥基内部主要化学成分,以探究硫酸盐对水泥基材料的侵蚀规律.试验结果表明:细小的硫酸渣粉可有效改善水泥石的孔结构,减缓硫酸根离子的侵蚀速率,并且与空白样对比,掺有硫酸渣粉的砂浆试件内部的Ca(OH)_2和石膏的量有所减少,表明硫酸渣粉与水泥水化产物Ca(OH)_2发生了化学反应,降低了水泥石的易蚀成分.不同比例硫酸渣粉的引入,并未提高水泥砂浆的抗压强度,但在一定程度上,改善了水泥材料的抗蚀性能.     

聚苯胺/镍纳米复合材料原位复合与性能表征

采用先合成导电聚苯胺,然后用多元醇原位液相还原的方法,合成了聚苯胺/镍纳米复合材料,纳米镍的含量约为19.22%(质量分数)。具有面心立方晶体结构,生成的纳米镍“镶嵌”在聚苯胺颗粒的表面,形成了类似“草莓”状的复合颗粒,复合颗粒的热稳定性有较明显提高。复合颗粒同时具有铁磁性和导电性,复合颗粒的饱和磁化强度最高可达到10.77Am2/kg,电导率为9.86×10-3S/cm。     

含Cr_2O_3不锈钢熔渣导电性的研究

采用4探针法(Mo丝)对含Cr_2O_3不锈钢熔渣电导率进行测试,研究Cr_2O_3含量和碱度对熔渣电导率随温度变化的影响,并得出不同渣系的电导活化能。结果表明:在实验温度范围内所有熔渣的电导率均随温度的下降而降低,在碱度为1.00,1.25和1.50时熔渣电导率随Cr_2O_3含量的增加而减小;当熔渣中Cr_2O_3含量相同时,碱度由1.00增加到1.50,电导活化能增加,熔渣电导率随温度降低而下降速率加快。对熔渣进行淬冷,并对淬冷渣样进行X射线衍射(XRD)分析。结果表明,在淬冷条件下,渣中仍析出尖晶石相和钙镁硅石相,揭示了熔渣在降温过程中电导率下降的原因。     

粉剂熔化性对顶吹喷粉钢水脱磷动力学的影响

对悬挂式顶吹喷粉精炼的钢水脱磷速率进行了理论和实验研究．应用传质原理的双膜理论，分别考虑气粉流直接冲击钢水面的过渡相接触区和顶渣的稳定相接触区，建立了顶吹喷粉钢水精炼的动力学模型．考查了供粉强度和渣粉熔化特性对精炼速率的影响．结果表明，即使在渣粉熔点较低的情况下，稳定相接触区对整个精炼过程也有着重要的贡献．增加供粉强度可增加稳定相接触区反应所占的比例，但对过度相接触区无影响，降低渣粉熔点可显著提高过渡相接触区的精炼效率，从而提高整个精炼过程的速率．     

氨水中合成异丙醇胺的反应动力学

研究了氨水与环氧丙烷合成异丙醇胺的反应规律,考察了氨与环氧丙烷的摩尔比、反应温度对反应的影响,在n(NH3)/n(H2O)为5、反应温度32℃、反应时间42min时,MIPA、DIPA、TIPA、选择性分别为49．3％、45．5％和5．2％,环氧丙烷转化率达98．8％,并对实验数据进行了回归,得到该反应的动力学模型,数据计算结果表明,模型的计算值与实验测定值吻合较好。     

滚筒渣与热闷渣基础性能研究

为实现钢渣的高效资源化利用,采用X射线荧光光谱（XRF）、X射线衍射（XRD）、扫描电镜（SEM）、粒径分布、安定性、易磨性等检测方法研究了滚筒法、热闷法处理工艺对钢渣基础性能的影响. 研究表明:滚筒渣和热闷渣的主要化学成分和物相组成相差不大,滚筒渣中硅酸二钙(C₂S)、硅酸三钙(C₃S)和铁酸二钙(C₂F)的质量分数较大,且可以较明显的观察到金属铁粒; 与热闷渣相比,滚筒渣中CaO质量分数较大,而 f-CaO质量分数较少.在2.0 MPa饱和蒸汽下进行压蒸试验发现,在相同粒径范围内,滚筒渣的安定性指数普遍大于热闷渣,安定性优异. 采用水泥试验小磨进行粉磨,得到比表面积随粉磨时间延长的特征曲线. 结果发现,在相同的粉磨时间内,滚筒渣的比表面积均小于热闷渣的比表面积,当粉磨时间超过70 min时,滚筒渣的粉磨效率趋于平缓,而热闷渣继续粉磨到110 min时,比表面积增加15.67%,因此滚筒渣的易磨性较差.粒度筛分与压碎值测定试验结果显示,滚筒渣的粒径大部分集中在3~5 mm,热闷渣主要集中在3~10 mm且粒度分布较均匀; 滚筒渣和热闷渣粗细骨料的压碎值均达到Ⅰ类粗细骨料技术指标,可直接用作粗细骨料.     

粉剂熔化性对顶吹喷粉钢水脱磷动力学的影响

对悬挂式欠喷粉精炼的钢水脱磷速率进行了理论和实验研究，应用传质原理的双膜理论，分别考虑气粉流直接流击钢水面的过渡相接触区和顶渣的相接触区，建立了顶吹喷粉钢水精炼的动力学模型，考查了供粉强度和渣粉溶化特性对精炼速率的影响，结果表明，即使在渣侵占为较低的情况下，稳定相接触区对整个精炼过程中也有着重要的贡献，增加供粉强度可增稳定相接触区反应所占的比例，但对比相接触区无影响，降低渣粉熔点可显著提高过渡相接     

矿渣-钢渣发泡混凝土的制备及反应机理

为了实现高炉矿渣、转炉钢渣的高附加值综合利用,以水淬高炉矿渣和转炉钢渣为主要原料,加入少量的脱硫石膏、石灰和水泥熟料,通过铝粉发气制备发泡混凝土.测试了不同矿渣-钢渣掺量制备的发泡混凝土制品3、7、28 d的抗压强度和容重,并用扫描电子显微镜和X射线能谱仪分析了发泡混凝土制品养护过程中的水化产物和微观结构的变化.结果表明,钢渣掺量为30％、矿渣掺量为45％时,两者的协调性比较强,制品的抗压强度达到5.1 MPa,绝干容重为625 kg/m3;该凝胶体系中有钙矾石和C-S-H凝胶协同生成,且转炉钢渣的水硬活性明显低于水淬高炉矿渣.     

冶金渣制备生态型人工鱼礁混凝土的试验研究

通过正交试验研究了矿渣钢渣熟料石膏体系胶凝材料的强度。胶凝材料正交试验表明：矿渣：钢渣的复合比为7∶1,矿渣和钢渣的比表面积分别为480 m 2·kg -1和550 m 2·kg -1,并与10%的水泥熟料和10%的脱硫石膏复合的胶凝材料具有较高的强度。以优化后的胶凝材料代替水泥,并以热闷法稳定化的钢渣颗粒为骨料,可以制备出抗压强度达到65 MPa以上的人工鱼礁混凝土。利用XRD和SEM方法分析胶凝材料的水化过程,结果表明,水化反应主要生成AFt相和C-S-H凝胶,钢渣、水泥熟料和脱硫石膏的协同作用对矿渣的火山灰活性反应具有重要促进作用。     

钢渣砂特性与稳定性研究

通过筛分和坚固性试验,结合SEM、XRF和XRD测试技术研究了钢渣砂的几何性质、力学性能、化学成分和矿物组成等特性,分析其做细集料的可行性。用常压蒸气粉化率法和215℃、2.0 MPa压蒸粉化率法并结合XRD图谱分析了不同试验条件下影响粉化率大小的主要因素。研究结果表明:钢渣砂的各项特性不仅符合GB/T14684—2001建筑用砂标准而且具有一定的水硬活性,坚固性f、-CaO含量和活性差异及RO相是影响钢渣砂稳定性的主要因素。     

Microstructure and Composition of Hydration Products of Ordinary Portland Cement with Ground Steel-making Slag

1　IntroductionSteel makingslagisthewasteofsteel makingindus tryandnearlysixteenmilliontonssteel makingslagisproducedinChinaperyear[1] .Justasflyashandblastfurnaceslag ,itisoneofthreekindsofdominantindustrywastesinourcountry .Eventhoughsteel makingslagce menthasdevelopedformorethantwentyyearsinCh ina[2 ,3 ] ,comparedwithothertwowastes ,thestudyandap plicationonsteel makingslagincementandconcreteareinsufficientyet.Moststeel makingslagcementsarepre paredbyinter grindingprocess ,sotheparticlesiz…     

Strength of limestone-based non-calcined cement and its properties

A new type of cement was prepared with ground limestone powder, blastfurnace slag, steel slag and gypsum without calcination. The fraction of ground limestone powder in the cement was as high as 40 wt%–60 wt% without Portland clinker. All of its physical properties can meet the requirements of masonry cement standards. The impact of limestone content on physical properties of the cement and determined its impact on law was investigated. The steel slag can excit the aquation activity of this cement effectively, and the influence of its quantity on the strength of the materials was studied, which shows that the optimum quantity of mixing is 10%. By way of changing the different content of the lime stone by quartzy sample, the law of the compression strength and the PH value was determined, confirming that the lime stone can promote the early aquation of the slag and improve the early strength. The main hydration product of this cement is calcium aluminate hydrate, ettringite and calcium silicate hydrate, as indicated by XRD and SEM analysis.     

Optimization of Blended Mortars Using Steel Slag Sand

A new kind of mortar made of ground granulated blast-furnace slag （GGBFS）, gypsum, clinker and steel slag sand （〈4.75 mm） was developed. The ratio of steel slag sand to GGBFS was 1 ： 1 and the amount of gypsum was 4% by weight while the dosage of clinker ranged from 0% to 24%. The optimization formulation of such mortar was studied. The content of steel slag sand should be less than 50% according to the volume stability of blended mortar, and the dosage of clinker is about 10% based on the strength development. Besides strength, the hydration heat, pore structure and micro pattern of blended mortar were also determined. The experimental results show the application of steel slag sand may reduce the dosage of cement clinker and increase the content of industrial waste product such as GGBFS, and the clinker is also a better admixture for blended mortar using steel slag sand.     

Research on Hydration of Steel Slag Cement Activatedwith Waterglass

This paper studied the hydration and strength influence factors of Steel Slag Cement (SSC), such as the quantity of steel slag and slag and the dosage of additive. The results show that: (a) In the process of hydration of SSC,steel slag and slag activate each other; (b) Waterglass's structure forms the preliminary skeleton of SSC,and the hydration products of SSC link or fill in the skeleton; (c) Sodium in waterglass is the catalytic and its concentration does not change in the process of hydration. (d) Structure of activation is a significant factor to the property of SSC.     

Accelerated carbonation and leaching behavior of the slag from iron and steel making industry

Ground granulated blast furnace slag （GGBFS） and steelmaking slag have been used as a raw material for cement production or as an aggregate to make concrete, which contribute aluminum, calcium, iron, and silicon oxides. The suitability of the slag for a particular application depends on its reactivity, cost, availability, and its influence on the properties of the resulting concrete. For the interest of durability studying of concrete in the presence of slag, the accelerated carbonation products and leaching behavior of the slag and Portland cement （PC） were studied. The experimental results confirmed that the slag was more resistant to carbonation compared to PC. The carbonation degree of GGBFS reduced by 17.74%; and the carbonation degrees of steelmaking slags reduced by 9.51%- 11.94%. Carbonation neutralized the alkaline nature of the hydrated pastes and gave rise to the redox potential of the leachate slightly （30-77 mV）. The carbonation also increased the release of most of the elements presented, except for calcium, to the aqueous environment. It is concluded that blend cements （PC plus slag） have economical advantages and better durability compared to PC,     

Methods for improving volume stability of steel slag as fine aggregate

Suitable methods for enhancing the volume stability of steel slag utilized as fine aggregate were determined. The effects of steam treatment at 100 ℃ and autoclave treatment under 2.0 MPa on the soundness of steel slag sand were investigated by means of powder ratio, linear expansion, compressive and flexural strength. DTA, EDX, XRD and ethylene glycol methods were employed to analyze both the treated slags and susceptible expansion grains. Experimental results indicate that powder ratio, content of free lime and rate of linear expansion can express the improvement in volume stability of different treated methods. Steam treatment process cannot ultimately prevent specimens from cracking and decrease of strength, but mortar made from autoclave treated slag keeps integration subjected to hot water of 80℃ until 28 d and its strength do not show significant decrement. The hydration of over-burn free lime and periclase phase are the main cause for the disintegration or crack of untreated and steam treated steel slag＇s specimens. Autoclave treatment process is more effective than steam treatment process on enhancement of volume stability of steel slag.     

Effect of Fine Steel Slag Powder on the Early Hydration Process of Portland Cement

1 IntroductionSteel slag is the waste residue of fluxing mineralsused in the process of steel producing. Its dischargeamount is about 10 % of the production of steel . Steelslag hasn’t been utilized widely and effectively in a longperiod of time[1]. Hundreds of million tons of steel slagare deposited,andthe amount is still increasing withtensof milliontons every year .The deposited steel slag occu-pies great amounts of farmlands and induces serious en-vironment problems . The main chemical c…