Borate Distribution in Stabilized Stainless-Steel Slag

Disintegration of stainless-steel slag during cooling is caused by the β→γ transformation of dicalcium silicate (2CaO·SiO₂ or C₂S). It is well established that disintegration can be avoided by borate additions, which are commonly believed to stabilize the high-temperature polymorphs by forming a solid solution with C₂S. In this study, the borate distributions in slowly cooled synthetic and industrial slag samples are determined. The slag microstructures are characterized using electron probe microanalysis (EPMA), quantitative X-ray diffraction (QXRD), and wavelength dispersive spectroscopy (WDS). The results show that only a limited fraction of the added borates forms a solid solution with the C₂S phase, while the main fraction is found in a calcium borosilicate phase. In combination with literature data, this suggests that slag stabilization involves more than the chemical stabilization of the high-temperature C₂S polymorphs.     

Chemical Corrosion Mechanisms of Magnesite-chrome Bricks by Converter Slag

The corrosion resistance of four kinds magnesitechrome bricks against converter salg was investigated by static crucible slag tests. The microstructures of the asdelivered and tested refractories were analyzed by means of SEM and EDS. The results showed that： Different magnesite-chrome bricks have different slag resistances. Generally, the slag resiantance sequence is as follows： rebounded fused magnesite-chrome brick 〉 semi-reboun- ded magnesite-chrome brick 〉 direct-bonded magnesitechrome brick 〉 silicate bonded magnesite-chrome brick. Slag reacts with the periclase of magnesite-chrome refractories, which results in the dissoving of periclase in fayalite slag. However, the complex spinels have superior slag resistance.     

钢渣沥青混合料微波加热自愈合性能研究

为了研究钢渣沥青混合料微波加热自愈合性能,制备了全石型、粗石细钢型、粗钢细石型、全钢型4种沥青混合料,采用热常数分析仪和矢量网络分析仪测试了沥青混合料的热参数和电磁参数,利用热电偶温度传感器和红外测温仪测试了沥青混合料的温度分布,并对比分析了COMSOL软件数值模拟温度场与试验温度分布;最后,采用三点弯曲破坏试验评价了沥青混合料的自愈合性能。结果表明:4种沥青混合料具有不同的微波吸收性能和传热性能,会对沥青混合料的加热速率产生一定影响;钢渣的掺入大大提高了沥青混合料的微波加热性能,且3种钢渣沥青混合料中粗石细钢型表现出较好的加热均匀性;COMSOL软件能够较好地模拟沥青混合料在微波加热下的温度分布;相比于全石型沥青混合料,粗石细钢型、粗钢细石型、全钢型沥青混合料的自愈合性能分别提高了1.11倍、1.14倍、1.11倍,钢渣的掺入较好地提高了沥青混合料的自愈合性能。     

炼镍转炉溅渣护炉过程中溅渣层形成机理

对炼镍转炉溅渣护炉期间镁铬残砖溅渣层的化学成分、熔化温度、粘度、物相结构及形成机理进行了研究. 结果表明,溅渣初始砖衬表面形成了以铁氧化物为主的过渡层;炉渣进一步挂结,形成由铁镁橄榄石和磁铁矿构成的粘渣层,其中MgO含量上升至11.01%,半球点温度达1424℃;溅渣后下一炉冶炼过程中,过渡层中铁氧化物通过扩散与镁铬砖作用形成以高铁尖晶石和镁铁固溶体为主的反应层,其中Fe2O3含量由1.33%增至18.43%,半球点温度升高至1598℃. 砖衬单炉损耗率降低近一半,炉龄大幅提高.     

转炉滚筒钢渣用于制品中的试验研究

介绍了转炉滚筒钢渣应用于制品的试验研究.从原材料选择、配比研究、性能检测、安全性和耐久性验证方面进行了大量的基础试验和应用试验,最终确定性价比好且符合制品要求的最佳配合比.规定了转炉滚筒钢渣游离氧化钙上限,验证了转炉滚筒钢渣集料(0 ～ 6mm)和转炉滚筒钢渣微粉可用于制品生产的可行性,掺入量达原材料总量的35％,且产品性能满足GB 28635-2012《混凝土路面砖》标准要求.     

响应面法稳定性二氧化氯制备的优化

以过氧化氢法制备二氧化氯工艺为基础,提出以过氧化氢、复合催化剂构成复合还原剂制备稳定性二氧化氯消毒剂的方法。通过分析单因素的影响,以二氧化氯产率为响应值,采用响应面试验设计方法对复合还原剂法制备稳定性二氧化氯工艺条件进行优化。结果表明:反应温度64℃、反应酸度5.3 mol/L、复合催化剂中A含量比0.66条件下,可制得二氧化氯产率为94.77%。     

转炉渣中铁资源的提取工艺研究

采用溶剂热结晶法,以转炉渣为原料,H2SO4为浸出剂,聚乙二醇为溶剂,氢氧化钠为沉淀剂,可以制备高纯Fe2O3微粉。研究确定了合理的工艺参数：pH值为5,温度为160℃。随着pH值的升高,反应时间可以由90 min缩短到30 min,Fe2O3晶体从粒状逐渐向片状晶过渡,纯度逐渐降低。当反应温度由140℃升高到170℃时,Fe2O3晶体的平均粒度由50 nm增加到800 nm,晶体的均匀性逐渐降低,晶体形态由球晶向针状晶过渡,Fe2O3晶体的纯度逐渐升高。     

磷渣粉体颗粒表面粗糙度的定量表征

采用盒维数估计其表面粗糙程度,并研究盒维数与需水量比和泌水率的关系。结果表明：分维值的大小定量表征了磷渣粉体颗粒表面的粗糙程度,分维值愈大,其表面愈粗糙,需水量比亦愈大,而泌水率愈小。     

成分改质对转炉钢渣方镁石的影响

方镁石的水化反应是制约转炉钢渣作为硅酸盐水泥材料的因素之一.依据实际转炉钢渣的成分特性,建立了以CaO-MgO-SiO2-Fe2O3-P2O5为主的实验渣,通过对此渣系的方镁石性质的深入研究,提出了成分改质法来消除渣中方镁石,研究结果如下:高碱度(C/S)转炉钢渣的镁元素主要以游离态方镁石形式存在,且固溶了少量的Fe、Mn等二价金属元素,而其它矿物中不含镁;随改质剂SiO2含量不断增加,实验渣的方镁石数量逐渐减少;当加入20％的SiO2后,即C/S值小于1.67,方镁石基本消失.而减少的方镁石会溶入C2S和C2F矿物,最终以CMS和MF形式稳定存在.研究证实成分改质处理方法可消除转炉钢渣的游离方镁石,进而利于它的资源化利用.     

水杨酸溶液萃取转炉钢渣中硅酸盐相的研究

研究了水杨酸-甲醇(SAM)溶液萃取钢渣中硅酸盐相的可行性,分析了钢渣比表面积、溶解时间和水杨酸浓度对萃取硅酸盐相量的影响,利用XRF和XRD分别测定了萃取后残渣的化学组成和矿物成分,以判别SAM溶液萃取硅酸盐相的效果.结果表明:常温下,5g比表面积为600m/kg的钢渣,经300mL SAM溶液(水杨酸浓度为0.2g/mL)萃取3h,钢渣中的硅酸盐相可完全溶解,其他矿物不溶或溶解甚微.分析指出,硅酸盐相溶解于SAM溶液的原因是由于水杨酸电离出的配体(HO-C6H4-COO-)与矿物表面阳离子(Ca2 )生成的络合物,通过键极化作用削弱Si-O键的稳定性,从而降低了硅酸盐溶解活化能.     

Twelve-Nitrogen-Atom Cyclic Structure Stabilized by 3d-Element Atoms: Quantum Chemical Modeling

Using various versions of density functional theory (DFT), DFT M06/TZVP, DFT B3PW91/TZVP, DFT OPBE/TZVP, and, partially, the MP2 method, the possibility of the existence of 3d-element (M) compounds with nitrogen having unusual M: nitrogen ratio 1:12, unknown for these elements at the present, was shown. Structural parameter data were presented. It was shown that all MN4 groupings have tetragonal-pyramidal structure. It was noted that the bond lengths formed by nitrogen atoms and an M atom were equal to each other only in the case of M = Ti, V, Cr and Co, whereas for other Ms, they were slightly different; moreover, the bond angles formed by nitrogen atoms and an M atom were equal to 90.0°, or practically did not differ from this value. Thermodynamic parameters, NBO analysis data and HOMO/LUMO images for this compound were also presented. Good agreement between the calculated data obtained using the above three quantum chemical methods was also noted.     

聚稳丁腈橡胶的结构与性能研究

研究聚稳丁腈橡胶DN3305（简称DN3305）生胶的微观结构以及胶料的性能,并与普通丁腈橡胶3305E（简称3305E）进行对比。结果表明：DN3305的分子结构与3305E差异不大,相对分子质量及其分布与3305E接近,玻璃化温度高于3305E;DN3305混炼胶的门尼粘度低于3305E混炼胶,硫化特性相近,加工性能较好;DN3305硫化胶的300%定伸应力和拉伸强度高于3305E硫化胶,在110 ℃×28 d热空气老化后DN3305硫化胶仍有一定的弹性,具有较好的耐热空气老化性能,耐油性能也较好。对于非耐低温的丁腈橡胶制品,可用聚稳丁腈橡胶替代普通丁腈橡胶以获得优异的耐高温性能。     

转炉渣微区CaO-SiO2-FeO氧化物分布特性研究

采用扫描电镜的背散射电子成像(BSE)和X射线能谱分析,对转炉双渣操作工艺下的前期渣和终渣进行物相分析和元素分布特征分析,研究表明:在炉渣微观区域内,Ca元素与Si元素相互附着存在,而Fe元素赋存在Ca元素和Si元素含量较少的区域,P元素大多出现在Ca、Si元素含量较多区域.炉渣微区内随着CaO含量增大,微区中SiO2含量呈增加趋势;炉渣微区内随着CaO含量增加,aCaO活度增加,而微区aFeO活度先增加后降低.随着FeO含量较大,SiO2摩尔分数和活度系数均有所降低,微区中SiO2含量呈逐渐降低的趋势.     

210 t顶底复吹转炉溅渣护炉模拟研究

对某厂210 t顶底复吹转炉进行了溅渣护炉水模型实验,测定了炉衬不同部位的溅渣量,考察了操作参数对溅渣效果的影响,得到最佳工艺操作参数为：顶吹流量50000 Nm3/h,枪位3680 mm,氧枪喷头倾角15°,留渣量21 t,底吹元件布置方式A1,底吹流量900 Nm3/h.     

Periclase-Carbon Refractories for Service in the Slag Zone of an Oxygen Converter

Based on data of petrographic and x-ray spectral microprobe analyses of periclase-carbon specimens sampled from the refractory lining of a decommissioned oxygen converter, a mechanism for the corrosive attack of slag on the refractory material is proposed and its kinetic parameters discussed.__________Translated from Novye Ogneupory, No. 1, pp. 29 – 31, January, 2005.Based on materials reported to the 8th Congress of Steelmakers (18 – 22 October, 2004, Nizhny Tagil, Russia).     

脱硫石膏钢渣无熟料水泥对软土固化效果的研究

利用脱硫石膏钢渣无熟料水泥固化软土,既可以充分利用工业废渣,又能减少水泥的用量,保护自然资源.通过研究在不同掺入比和不同龄期时固化土的无侧限抗压强度,分析了掺入比、龄期对固化土强度的影响.试验结果表明,脱硫石膏无熟料水泥固化早期强度较低,与水泥相比不同掺入比时随龄期的增长固化强度变化较大.当脱硫石膏钢渣无熟料水泥的掺入比较水泥的掺入比大5％时,在龄期达到28 d以后,其固化强度与水泥土的固化强度相当.     

Crystal Structure of Orthorhombic Zirconia in Partially Stabilized Zirconia

A neutron powder diffraction investigation confirms that, in tough magnesiapartially-stabilized zirconia cooled to 30 K, most of the tetragonal zirconia transforms to an orthorhombic phase. This phase is retained on heating to room temperature; the lattice parameters at 295 K are a = 0.5068, b = 0.5260, and c = 0.5077 nm. The room-temperature crystal structure (space group Pbc2₁) is determined by multiphase Rietveld refinement from the neutron diffraction pattern. This orthorhombic structure is compared with the parent tetragonal structure and with the structure of monoclinic zirconia, which it closely resembles.     

宝钢转炉钢渣用于耐磨超细薄层的研究

以不同掺比将宝钢转炉钢渣细集料替代砂料。钢渣替代比例为砂料的质量分数0、25%、50%、75%、100%,进行钢渣的耐磨超细薄层配比的设计,对不同配比的耐磨超细薄层进行性能研究,并开展铺装试验及其性能分析。     

海洋环境下矿渣混凝土的表面氯离子浓度规律

依据自然扩散法的原理,采用人工模拟海水为浸泡介质,研究了矿渣混凝土(Slag concrete,SGC)在海水环境中的氯离子扩散行为,探讨了养护龄期、暴露时间、矿渣(Slag,SG)掺量对混凝土表面氯离子浓度(Cs)的影响规律.结果表明,在海洋环境中,不论是普通混凝土(Ordinary Portland cement concrete,OPC)还是SGC,其Cs均随着养护龄期的延长而呈对数函数的下降规律,且随着暴露时间的延长而呈幂函数的增长规律,并逐渐趋于稳定.对于暴露时间为180 d的SGC,其Cs随着SG掺量的增加呈现先减后增的趋势,Cs最小的SG掺量为30％.因此,对于实际海洋环境下的混凝土结构,为了保证结构强度并考虑氯离子扩散系数的影响,应尽量延长养护的时间至365 d,同时使SG的掺量不低于30％,这样,有利于提高混凝土结构的服役寿命.