中钛型含钛高炉渣制微晶玻璃及其性能研究

以中钛型含钛高炉渣为主原料制备微晶玻璃,利用渣中的TiO_2作晶核剂。采用差示扫描量热法(DSC)、X射线衍射(XRD)和扫描电子显微镜(SEM)等分析技术研究了含钛高炉渣用量的变化对基础玻璃晶化、微晶玻璃性能的影响。结果表明,渣中适量的TiO_2对玻璃晶化有较好的促进作用。渣用量较低时制得的微晶玻璃的主晶相为硅灰石,但当渣用量超过70%时,主晶相发生变化,变为钙铝黄长石等长石类矿相。中钛型含钛高炉渣用量为63%左右时,制得的微晶玻璃晶相含量合适,性能最好。此时采用的热处理制度为:核化温度720℃,保温1h,晶化温度945℃,保温2h,制得的微晶玻璃抗弯强度为121.68 MPa,显微硬度为7.81GPa。     

钛渣晶核剂对赤泥粉煤灰微晶玻璃性能的影响?

采用烧结法以钛渣代替二氧化钛为晶核剂制备了高掺量的赤泥粉煤灰微晶玻璃,主要考查钛渣掺量对微晶玻璃产品的理化性能、物相组成及微观结构的影响.结果表明,主晶相均为钙铝黄长石,次晶相为钙铁透辉石和钙长石;结晶程度随钛渣含量而增加,微晶玻璃颜色逐渐变深,但钛渣含量过高,晶体会发生凝结现象;当钛渣掺量为6．6％时,固废总掺量达到了95．3％,抗压强度、抗折强度、显微硬度、耐酸性、耐碱性分别为89．43和53．13 MPa、6．62 GPa、0．041％、0．15％,产品性能达到建筑用微晶玻璃JC/T872-2000的质量标准.     

晶化温度对硅渣微晶玻璃形成机理和性能的影响

本文以硅渣为主要原料,利用熔融法制备了高强度微晶玻璃。采用差热分析(DTA)、X射线衍射(XRD)和扫描电镜(SEM)研究了不同晶化温度对硅渣微晶玻璃的晶相演变、显微结构、形成机理和样品性能的影响规律。研究结果表明:在最佳晶化温度870℃时,主晶相为铁板钛矿(Fe2TiO5)和透辉石(CaMgSi2O6)复合晶相,微观结构致密,晶粒呈球状,抗折强度为270MPa,维氏显微硬度为989.72MPa,耐化学腐蚀性能较好。     

多孔磷渣微晶玻璃的烧结及其力学性能

采用三步热处理方法及不同的烧结温度,加入造孔剂聚乙烯醇,将磷渣废玻璃基础玻璃粉末烧结成多孔磷渣微晶玻璃.针对多孔磷渣微晶玻璃的烧结密度、体积收缩卒、抗折强度和抗压强度进行试验分析,结果表明,有机物挥发温度为400℃并保温1h,核化温度为790℃并保温2h,晶化温度为1100～1200℃时,微晶玻璃的力学性能最佳.     

烧结温度对提钛渣微晶玻璃析晶及显微结构的影响

以攀枝花提钛渣为原料,通过直接烧结法制备了以钙镁黄长石、透辉石及钙钛矿为晶相的多相微晶玻璃。采用多种分析手段,研究了烧结温度(1170～1190℃)对微晶玻璃的析晶、显微结构及性能的影响。结果表明:随着烧结温度的升高,钙镁黄长石含量先减少后增加,透辉石含量先不变后减少;微晶玻璃中晶粒聚集程度增加,晶界延长,液相填充晶粒间的空隙并与晶粒相互咬合,显微结构致密;烧结温度能够影响微晶玻璃中液相的分布与含量;1185℃时微晶玻璃的线收缩率和体积密度达到最大,分别是14.41%和2.50g/cm~3,吸水率为1.45%;过高的烧结温度(1190℃)会降低致密程度。     

熔制保温时间对CAMS系矿渣微晶玻璃结构与性能的影响

以白云鄂博二次选后尾矿、高炉渣和粉煤灰为主要原料,采用熔融法制得CaO-Al_2O_3-MgO-SiO_2(CAMS)系微晶玻璃,利用DSC、XRD、SEM、EDS、Raman、红外光谱及理化性能测试手段,研究了熔制过程中不同保温时间对微晶玻璃结构与性能的影响。结果表明:随着熔制保温时间的延长,矿渣玻璃熔液中氟的挥发及对氧化铝坩埚的侵蚀导致基础玻璃中氟含量降低而Al2O3含量升高,基础玻璃析晶温度呈先上升后下降的趋势,微晶玻璃主晶相为透辉石,晶粒出现先细化后粗化的趋势,第二相萤石相随着保温时间的延长逐渐消失,最终导致微晶玻璃结构及理化性能发生改变。当玻璃熔制保温时间为5h时,制备的微晶玻璃综合性能最优,其密度、抗折强度、显微硬度及耐酸碱性分别为3.09g/cm3、201 MPa、7 021 MPa、97.78%和98.83%。     

ZrO2对低温烧结 BaO-Al2O3-SiO2系微晶玻璃析晶和晶型转变的影响

用烧结法制备了化学计量比和高Ba含量的两组BaO-Al2O3-SiO2(BAS)系微晶玻璃,采用差示扫描量热法(DSC)和X射线衍射分析(XRD)等手段研究了ZrO2对BAS系微晶玻璃中六方钡长石析晶和六方钡长石向单斜钡长石晶型转变的影响.研究表明,两组BAS系玻璃的烧结温度低于850℃,晶化温度低于900℃.六方钡长石的析出为整体析晶.不加形核剂晶型转变为整体析晶;添加ZrO2晶型转变为表面析晶.提高Ba含量或添加ZrO2促进六方钡长石的析出和晶粒细化.化学计量比的BAS系微晶玻璃中添加ZrO2明显促进晶型转变.高Ba含量的BAS系微晶玻璃中添加ZrO2表现为抑制晶型转变,850℃保温100h不发生转变.     

晶核剂对Li2 O-Al2 O3-SiO2系统微晶玻璃结构和性能的影响

通过传统熔体冷却法制得了以P2O5和TiO2为晶核剂的Li2O-Al2O3-SiO2系统基础玻璃,并经过热处理制得了微晶玻璃.利用红外光谱分析、X射线衍射分析和扫描电子显微镜等对晶化试样的物相和显微结构进行了研究,着重探索了不同晶核剂对玻璃析晶、微晶玻璃结构、微晶玻璃力学和热学性能的影响.结果表明:TiO2更有利于玻璃析晶,但以P2O5为晶核剂的微晶玻璃具有更好的力学和热学性能.     

自然冷却黄磷炉渣与脱硫石膏协同制备微晶玻璃

以自然冷却黄磷炉渣和脱硫石膏为基础原料,通过添加一定量的SiO2和Al2O3,熔融法制备了黄磷炉渣微晶玻璃.通过差热分析(DTA)、X射线衍射仪(XRD)和扫描电子显微镜(SEM)等方法分析了不同比例的黄磷炉渣与脱硫石膏对微晶玻璃晶化行为的影响.研究结果显示:在所添加黄磷炉渣与脱硫石膏的比例范围内,基础玻璃的核化温度和晶化温度随脱硫石膏加入量的增加逐渐下降,析晶活化能E先减小后增加;黄磷炉渣微晶玻璃的主晶相硅灰石(CaSiO3)并未因脱硫石膏添加量的增多而改变,但对硅灰石晶相的生成产生了先促进后抑制的效果.     

含钛高炉渣催化剂的光催化活性

以攀钢含钛高炉废渣为原料,在不同温度下煅烧合成了钙钛矿型硫酸掺杂的含钛高炉渣催化剂(sulfuric acid-modified titanium-bearing blast furnace slag,STBBFS),研究了混晶结构和硫掺杂对含钛高炉渣光催化活性的影响,结果表明,含钛高炉渣催化剂具有钙钛矿/锐钛矿混晶结构,粉体的颗粒形状不规则,煅烧后粒径变大;在紫外区域具有很强的光吸收能力,STBBFS催化剂的光催化活性由Cr(Ⅵ)的还原率评价.煅烧温度为400℃时,STBBFS催化剂的表面存在含量较高的SO2-4和较高的CaTiO3/TiO2晶相比,具有较高的光催化活性,用500 W中压汞灯照射10 h,可将浓度为20 mg·L-1的六价铬废水完全降解.     

Crystallization kinetics of magnetic glass–ceramics prepared by the processing of waste materials

The objective of the present investigation was to study the feasibility of conversion of an intimate mixture of blast furnace slag and blast furnace flue dust generated by a single industrial company into magnetic glass–ceramic product. Blast furnace slag (BFS) and blast furnace flue dust (BFD) are generated at a rate of 300,000 and 30,000 tons/year, respectively, from iron and steel factory. The crystallization mechanisms of a composition containing BFS and BFD in a 50/50 proportion were investigated by differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The crystallization temperature was found to vary from 900 to 1100 °C and two phases appeared in the crystallized samples: pyroxene Ca(Mg, Fe, Al)(Si, Al)₂O₆ and magnetite/maghemite. Heating rate and particle sizes effects on crystal growth of powdered samples were studied by DTA. The apparent activation energy of crystal growth using the particle size 180–315 μm was determined to be 355 and 329 kJ/mol for the first and second peak, respectively. The presence of sharp and broad crystallization peaks indicate simultaneous surface and internal crystallization mechanism. Good wear resistance and chemical durability particularly in alkaline environment, combine with good hardness and magnetic properties make this glass–ceramic material potentially useful for various industrial applications.     

热处理温度对熔融分相法制备纳米TiO2影响的研究

用熔融分相法制备TiO2光催化材料的原理基于通过调节分相结构控制析晶尺寸。本文重点研究在制备过程中热处理条件对玻璃分相与TiO2析晶及光催化效果的影响。试样的组成选在Na2O-B2O3-SiO2-TiO2体系的分相区域,1300℃熔融,在不同的温度下进行热处理,经酸处理后得到负载于富硅多孔玻璃的纳米TiO2光催化材料。结果表明为使分相尺寸与TiO2析晶速度相匹配,获得最佳的光催化效率,对不同组成的试样热处理条件以575～600℃／12h为宜。     

Investigation on the effect of MgO content on the crystallization behavior of synthetic BF slag

The crystallization of molten blast furnace (BF) slag can increase its viscosity and reduce its liquidity; it can also affect the quality of slag fibers following their manufacture. The crystallization behavior of BF slag is influenced by its chemical composition. In this study, four synthetic BF slags with various MgO contents, ranging from 6 to 12%, were investigated. FactSage simulations were performed to predict the types of crystallized phases as well as their mass fractions that are developed within the synthetic BF slags during the cooling process. To verify the validity of FactSage simulation, X-ray diffraction and scanning electron microscope–backscattered electron imaging, where the equipment was coupled to an energy-dispersive spectrometer, were performed to explore the mineralogical compositions and morphologies of the synthetic BF slags. Experiments using the hot thermocouple technique were performed to identify the initial crystallization temperatures of the synthetic BF slags. The results indicate that the observed phases of the synthetic BF slags were primarily composed of akermanite (2CaO?·?MgO?·?2SiO₂) and gehlenite (2CaO?·?Al₂O₃?·?SiO₂), which could form a solid solution, melilite, and control the initial crystallization temperature. The initial crystallization temperature increased as the MgO content of the slag increased. A low initial crystallization temperature was achieved in the cases of the synthetic BF slag samples with MgO contents of 6–8%; these slags were considered suitable for the manufacture of slag fiber.     

应用低钛高炉渣的半钢炼钢:脱磷热力学与工业试验

基于低钛高炉渣资源化综合利用和提高转炉半钢炼钢脱磷效果的考虑,对低钛高炉渣进行喷吹CO_2法脱硫处理后,配入25%~30%的氧化铁皮制备成半钢化渣球用于半钢炼钢。采用建立半钢渣系的脱磷热力学模型和工业试验的方法,对此半钢化渣球冶炼半钢的脱磷能力和冶金效果进行研究。研究结果表明:随着炉渣中TiO_2和Al_2O_3含量的升高,炉渣的脱磷能力降低,特别是当炉渣碱度和温度较低时,脱磷能力降低更快;在两种氧化物含量相同的情况下,TiO_2比Al_2O_3的负面影响更大;随炉渣碱度的增加,炉渣的磷分配比和磷容量均呈先升高后持平的趋势;随渣中w(FeO)的增加,炉渣的磷分配比和磷容量均先升高后降低;随w(MgO)的降低,炉渣的磷分配比和磷容量逐渐降低。采用半钢化渣球冶炼半钢,渣中w(TiO_2+Al_2O_3)和w(FeO)升高,炉渣碱度和w(MgO)降低,控制炉渣碱度在4.0左右,炉渣不仅具有较高的磷分配比和磷容量,并且可以弱化(TiO_2+Al_2O_3)对脱磷能力的影响,确定其加入比例为总渣量的15.0%~20.0%。留渣+化渣球法冶炼半钢的前期平均脱磷率增至58.59%,为原冶炼工艺的1.57倍,吨钢石灰消耗和终点钢水[O]含量分别下降3.48kg/t和112×10-6。     

热处理对Mg-Al-Si-Ti-B系微晶玻璃析晶及介电性能的影响

采用差热分析仪(DSC), X射线衍射仪(XRD)及扫描电子显微镜(SEM)等测试手段, 研究了不同烧结制度下19MgO-23Al₂O₃-53SiO₂-4TiO₂-2.5B₂O₃(wt%, M-A-S-T-B)系微晶玻璃样品的析晶过程、相成分与含量及微观形貌, 并分析了核化与晶化时间对材料微波介电性能的影响关系。结果表明, 根据玻璃受控析晶机制, 当热处理制度为850℃/2 h+950℃/2 h时, 斜顽辉石(MgSiO₃)相得以较好的析出, 且伴随有α-堇青石(Mg₂Al₄Si₅O₁₈)、镁铝硅酸盐(xMgO-yAl₂O₃-zSiO₂)和方石英(α-SiO₂)相的析出。随着核化时间的延长, M-A-S-T-B体系各晶相种类及析出量变化不明显; 而随着晶化时间的延长(20 h), 材料的晶化程度提高, 品质因数(Q×f)得以提升, 颗粒状晶粒析出趋于显著; 但当晶化时间进一步延长至30 h时, 样品致密度降低, 介电损耗略有增大。在热处理制度为850℃/2 h+950℃/20 h下, 样品获得的微波介电性能较优: ε_r=3.85、τ_f ≈-5.37×10^-6/℃和Q×f ≈12740 GHz(f₀=13.973 GHz)。     

Vitrification of copper flotation waste

The vitrification of an hazardous iron-rich waste (W), arising from slag flotation of copper production, was studied. Two glasses, containing 30wt% W were melted for 30min at 1400 degrees C. The first batch, labeled WSZ, was obtained by mixing W, blast furnace slag (S) and zeolite tuff (Z), whereas the second, labeled WG, was prepared by mixing W, glass cullet (G), sand and limestone. The glass frits showed high chemical durability, measured by the TCLP test. The crystallization of the glasses was evaluated by DTA. The crystal phases formed were identified by XRD resulting to be pyroxene and wollastonite solid solutions, magnetite and hematite. The morphology of the glass-ceramics was observed by optical and scanning electron microscopy. WSZ composition showed a high rate of bulk crystallization and resulted to be suitable for producing glass-ceramics by a short crystallization heat-treatment. WG composition showed a low crystallization rate and good sinterability; glass-ceramics were obtained by sinter-crystallization of the glass frit.     

基于有限元法模拟微晶玻璃的微晶化加热过程

以CaO-Al_2O_3-SiO_2系基础玻璃为研究对象,基于ANSYS有限元分析对基础玻璃微晶化过程进行了数值模拟,得到了基础玻璃内部中心点和端点温度场随时间的变化曲线方程。结果显示,在从室温加热到核化温度阶段(25~780℃)和从核化温度加热到晶化温度阶段(780~1 080℃),基础玻璃内部的中心点温度和端点温度值随时间变化与指数方程拟合度较高。为防止在加热过程中温度场中有较大的温度梯度分布和热应力的产生,在25~780℃阶段的升温速率应控制在2~4℃/min;在780~1 080℃阶段的升温速率应控制在0~2℃/min。通过差热分析和X射线衍射等分析手段对以3℃/min的升温速率升至核化温度(780℃)后又以1℃/min的升温速率升至晶化温度(1 080℃)后制得的CaO-Al_2O_3-SiO_2系微晶玻璃进行了实验验证,得到了主晶相为硅灰石(CaSiO_3)和含铁硅灰石类固溶体((Ca,Fe)SiO_3)且性能优异的微晶玻璃。     

Ultra low and negative expansion glass-ceramic materials produced from pyrophyllite and blast furnace slag

Ultra low and negative expansion glass-ceramic materials have been obtained from pyrophyllite and blast furnace slag. The batch composition was modified with the addition of lithium carbonate, hydrated alumina, boric acid and nucleating agent (titania). The batch was melted at 1400°C followed by casting in the form of bars and annealed at 510°C for 4 h. The annealed specimens were subjected to heat treatment at predetermined temperatures selected from DTA study of the parent glass. Thermal expansion measurement and X-ray diffraction analysis revealed that the specimen nucleated at 545°C for 4 h and crystallized at 720°C for 2 h which resulted in negative coefficient of thermal expansion [(-) 9 to (-) 2 x 10^-7/°C] over the temperature range (30-600°C) due to the formation ofβ bd-eucryptite while other heating schedule showed the formation of spodumene and lithium aluminium silicates. The samples showed excellent flexural strength value and varied in the range 120–200 MPa depending upon the phases present.     

TiO2纳米管阵列薄膜的水热晶化

首先在KF和乙二醇的混合溶液中利用阳极氧化技术在钛基底表面制得了一层排列整齐、形貌均一的TiO₂纳米管阵列薄膜,然后将制得的薄膜进行水热处理,通过扫描电子显微镜、X射线衍射仪等表征手段研究了水热处理温度和时间对TiO₂纳米管阵列薄膜表面形貌、结晶度以及管状结构的影响。结果表明:水热处理即使在较短的时间内（如3 h）也可在较低温度下（如210℃）使TiO₂纳米管阵列薄膜由无定形转变为锐钛矿型结构;提高水热处理温度或延长水热处理时间均可提高薄膜的结晶度,但同时纳米管管壁结晶度增加会使管内径变小甚至堵塞,从而破坏管状结构。     

高温固相法制备钒掺杂含钛高炉渣光催化抗菌材料

采用高温固相法,掺杂不同质量分数的V2O5,在800℃煅烧2h合成了钒掺杂的含钛高炉渣催化剂(vanadium oxide modified titanium bearing blast furnace slag,VTBBFS)。用X射线衍射、扫描电子显微镜和紫外-可见漫反射光谱仪对钒掺杂的含钛高炉渣催化剂进行了表征,确定其具有钙钛矿结构;粉体的颗粒形态均为不规则块状,800℃煅烧后出现了团聚现象;在紫外区域具有强光吸收能力,并发生红移。以白色念珠菌为实验菌种考察钒掺杂的含钛高炉渣催化剂抗真菌能力。结果表明,V2O5掺杂量为10%时,催化剂具有较强的抗白色念珠菌能力,在普通光照下杀菌率可达到100%。