正交试验法筛选煤气化灰渣制备泡沫陶瓷工艺条件

通过L_9(3~4)正交实验设计方法,探讨了发泡剂添加量、烧结温度、升温速率和烧结时间4个因素对泡沫陶瓷材料性能的影响,利用方差分析对制备泡沫陶瓷工艺进行优选。结果表明:利用粉煤气化灰渣制备泡沫陶瓷材料的最佳工艺条件为:烧结温度为1200℃,升温速率为4℃/min,保温时间为30 min,发泡剂的添加量为3%,此时泡沫陶瓷材料的体积密度为0.77 g/cm~3,抗压强度为3.4 MPa。极差结果分析表明,烧结温度、升温速率和发泡剂的添加量是影响材料性能的主要因素。     

利用废岩棉制备高性能泡沫玻璃陶瓷的实验研究

以工业垃圾废岩棉和废玻璃为原料，以CaCO₃为发泡剂制备出高强度泡沫玻璃陶瓷。研究了废岩棉和废玻璃的添加量及烧结温度对泡沫玻璃陶瓷材料性能的影响。结果表明：随着废岩棉添加量的增加和烧结温度的提高，熔体黏度会降低，不利于气泡结构的稳定；在废岩棉添加量为40%、750℃烧结温度下得到的样品容重为0.54 g/cm³、孔隙率为62.5%、抗压强度为4.76 MPa；样品主晶相为亚硅酸钙和石英晶相，加入TiO₂作为晶核剂后主晶相改变为榍石；TiO₂掺量为10%时，在750℃烧结20 min更经济，所得样品容重为0.82 g/cm³、孔隙率为50%、抗压强度为7.76 MPa。     

泡沫注凝法制备孔结构可调的氧化锆多孔陶瓷

以8%(摩尔分数)Y_2O_3稳定的ZrO_2为原料,采用泡沫注凝法制备了氧化锆多孔陶瓷,研究了烧结温度、固相含量及发泡剂浓度对制备材料的组分、结构与性能的影响规律。结果表明:1 450～1 600℃烧结的样品均由立方氧化锆组成;烧结温度对气孔率、体积密度及热导率影响较小,而对抗压强度及晶粒尺寸影响较大;固相含量在15%～30%(体积分数)范围内对材料的结构与性能均有明显的影响;发泡剂浓度在0.3～8.0 g/L范围内对材料的性能影响明显,而在8～16 g/L时影响不大。通过在一定的范围内调控烧结温度、固相含量和发泡剂浓度,所得样品的总气孔率、体积密度、抗压强度和室温真空热导率的变化范围分别为67.6%～78.8%、1.25～1.91 g/cm~3、6.3～21.7 MPa和0.14～0.39 W/(m?K)。在固相含量为30%、发泡剂浓度为2.0 g/L、烧结温度为1 550℃条件下制备样品总气孔率、抗压强度和热导率分别为78%、12.0 MPa和0.17 W/(m?K)。     

钼尾矿化学发泡法制备多孔陶瓷

为了资源化利用被废弃的钼尾矿,以陕南钼尾矿粉、石英粉、铝酸钙水泥为主要原料,双氧水为发泡剂,采用化学发泡-烧结法制备多孔陶瓷,主要研究了发泡剂添加量(外加,质量分数分别为1%、2%、3%、4%和5%)和烧结温度(分别为1 000、1 100℃)对多孔陶瓷显气孔率、体积密度、常温耐压强度和物相组成的影响。结果表明:1)随着双氧水添加量的增加,多孔陶瓷的显气孔率增大,体积密度和常温耐压强度减小。2)随着烧结温度的升高,多孔陶瓷的常温耐压强度明显增大。3)双氧水添加量为2%(w)、1 100℃煅烧制备的多孔陶瓷,其体积密度为0. 79 g·cm~(-3),显气孔率为69. 6%,耐压强度为0. 49 MPa;气孔大小一致,分布均匀,孔径300μm左右;主晶相为石英,次晶相为铝酸钙和氧化铝,并含少量钙长石。     

粉煤灰制备泡沫陶瓷工艺参数优化

以粉煤灰为原料,钾长石、硼砂、白云石为助熔剂,外掺适量碳酸钙、炭黑、碳化硅为发泡剂,用粉末烧结法制备泡沫陶瓷.针对碳酸钙、炭黑、碳化硅掺量以及发泡温度四个因素设计安排正交实验,对烧结样品的表观密度、孔隙率、抗压强度进行测定,采用极差分析法对实验数据进行处理分析.实验结果表明,碳酸钙掺加量为6％,炭黑掺加量为2％,碳化硅掺加量为3％,发泡温度为1080℃时,制品的综合性能最佳:表观密度为599.8 kg/m3,孔隙率为77.19％,抗压强度为2.23 MPa.     

低品位钾长石制备多孔保温隔热陶瓷研究

以低品位钾长石为主要原料,碳化硅为发泡剂,通过高温发泡法制备多孔保温隔热陶瓷.分别采用X-射线衍射(XRD)和超景深显微成像对保温隔热陶瓷的晶相组成和结构形貌进行表征,研究了烧结温度与保温时间对多孔保温隔热陶瓷孔结构、导热系数、抗压强度、体积密度和吸水率等性能的影响.结果表明,烧结温度为1250℃、保温时间为30 min时制备的多孔陶瓷材料性能最优,样品的导热系数为0.072 W/(m·K),抗压强度为3.429 MPa,吸水率为13.5％,体积密度为0.542 g/cm3.     

用Bayer法赤泥制备的多孔陶瓷滤料的结构与性能

实验以Bayer法赤泥为主要原料制备多孔陶瓷滤料,研究了赤泥添加量、烧成温度等对样品的烧成温度范围、显气孔率、压碎强度、耐酸耐碱性和显微结构等的影响.理化性能和显微结构测试表明:赤泥添加量和烧成温度是影响样品结构和性能的土要因素.赤泥添加质量达60%时,样品烧成温度为1 100℃,样品的显气孔率为31.78%,吸水率为15.34%,体积密度为2.07kg/m3,压碎强度为26.74MPa,耐酸性为93.54%,耐碱性为99.27%.样品的晶相组成为γ-Fe2O3、α-鳞石英、钠长石及斜辉石等,是一种气孔率高且强度高的优质滤料.     

用烧结法赤泥制备多孔陶瓷滤球的研究

本文以烧结法赤泥为主要原料制备了多孔陶瓷滤球,研究了赤泥添加量、烧成温度等对样品的烧成温度范围、显气孔率、压碎强度、耐酸耐碱性、显微结构等的影响。理化性能和显微结构测试表明,赤泥添加量和烧成温度是影响样品结构和性能的主要因素,二者对样品各项性能均产生交互式影响。赤泥添加量为50wt%、烧成温度1120℃时,样品的显气孔率为37.29%,吸水率为19.61%,体积密度为1.90kg/m3,压碎强度为24.54MPa,耐酸性为84.01%,耐碱性为98.98%,气孔分布均匀,呈三维连通状,可以满足用作污水处理过滤介质的要求。     

硼砂对粉煤灰多孔玻璃结构及性能的影响

选用粉煤灰和碎玻璃为基础原料,以碳酸钙为发泡剂,采用粉末烧结法制备多孔玻璃.采用SEM对试样微观形貌进行表征,并对成品表观密度、抗压强度、孔隙率等性能进行测定,研究添加剂硼砂对多孔玻璃孔径及其分布、孔隙率和性能的影响.实验结果表明,硼砂的添加起到了明显的助熔作用,并稳定了多孔玻璃孔径分布,且硼砂添加量为3.5%时效果较好,孔径分布均匀,孔隙率为48%左右.     

石棉尾渣和粉煤灰制备堇青石多孔陶瓷及其理化性能

低成本制备堇青石多孔陶瓷一直是专家学者们研究的热点,本文以石棉尾渣、粉煤灰、高岭土为原料,在不添加发泡剂的情况下,采用直接烧结法成功制备了堇青石多孔陶瓷,系统研究了堇青石多孔陶瓷的物相演化、显微结构及理化性能。结果表明:烧结温度的升高和配方中高岭土含量的增加有助于样品中堇青石的合成,高岭土的添加可以有效降低样品发泡的温度和提高样品的孔隙率;当烧结温度为1 240 ℃,焙烧后的石棉尾渣、焙烧后的粉煤灰和高岭土质量比为5∶5∶3时,制备的堇青石多孔陶瓷的体积密度仅为0.6 g/cm³,孔隙率高达76.94%;当烧结温度为1 220 ℃,焙烧后的石棉尾渣、焙烧后的粉煤灰和高岭土质量比为5∶5∶5时,制备的堇青石多孔陶瓷吸水率达到最大值34.57%;此外,制备的堇青石多孔陶瓷还表现出良好的耐碱性能。     

以粉煤灰和赤泥为原料烧结陶瓷工艺与性能研究

本文研究了在1050 ℃至1200 ℃之间温度对以粉煤灰赤泥为原料烧结陶瓷的物相和烧结性能的影响.结果表明:实验用粉煤灰原料的主要矿相组成为石英(SiO_2)和莫来石(3Al_2O_3·2SiO_2),赤泥原料的主要矿相组成有钙铝黄长石(Ca_2Al_2SiO_7)、石英(SiO_2)、钙铁榴石(Ca_3Fe_2+3(SiO_4)_3)和钙钛榴石(Ca_3TiFeSi_3O_(12));以粉煤灰赤泥为原料的5组不同配比试样在1200 ℃时试样气孔率相对降低,体积密度和抗压强度相对程度增大;其中5#试样在经1200 ℃烧结后的气孔率为1.67%,体积密度为2.10 g·cm~(-3),抗压强度为123.23 MPa,达到较好的烧结致密状态,试样主要物相是钙钠长石和莫来石.试样内莫来石的形成及玻璃液相的增加促进烧结并在1200 ℃达到致密烧结状态.     

Waste-bearing foamed ceramic from granite scrap and red mud

Using granite scrap and red mud as raw materials, SiC as foaming agent, powder sintering method was used to prepare closed-pore foamed ceramic. The effects of the ratio of red mud and granite scrap, foaming agent content, sintering temperature and holding time on the crystalline phase, pore structure, and performance of foamed ceramic were systematically studied. The results showed that, when the content of red mud was 10 wt%, together with 1.0 wt% SiC addition, the heating rate was 5°C/min, the foamed ceramic sintered at 1130°C for 30 min exhibited optimal properties, including bulk density of 483.11 kg/m³, porosity of 77.27%, compressive strength of 1.62 MPa and water absorption of .49%. Based on these properties, it possessed broad potential application prospects in the fields of sound and thermal insulation, lightweight construction materials. In this study, the utilization ratio of industrial solid waste was 100%, realized the comprehensive utilization of granite scrap and red mud, and provided a new idea to realize their low-cost utilization by preparing foamed ceramic with associated economic and environmental benefits.     

Novel glass ceramic foams materials based on red mud

Glass ceramic foams were prepared using red mud and fly ash with added CaCO₃ as foaming agents. The aim of the present work was to investigate the possibility of adding red mud, an alkaline leaching waste, in the raw material for the preparation of glass ceramic foams. The results of mineralogical analyses as well as the microscopic examination showed that the use of the red mud affect the mineralogical characteristics and structures of the as produced foams. The influence of amount of red mud on the bulk density and compressive strength of samples was further evaluated. The experimental results showed that relatively low bulk density foams (0.33–0.41 g/cm³) could be obtained by using low sintering temperature (760–840 °C) when the red mud/fly ash ratio does not exceed 40:60. The reduction of sintering temperature or, above all, the reduction of the holding time, was found to limit the coalescence and significantly improve the compressive strength of the foams (0.33–2.74 MPa).     

Preparation and characterization of porous anorthite ceramics from red mud and fly ash

The porous anorthite ceramics with high porosity, good mechanical strength and low heat conductivity were prepared using red mud and fly ash as raw materials via the pore forming method. The effects of sintering temperature and fly ash on phase evolution, densification, compressive strength, thermal conductivity and microstructure of the ceramic materials were investigated. The results showed that the compressive strength of the porous ceramics had an obvious improvement with the increase in fly ash, and the densification and heat conductivity decreased firstly and then increased. In particular, specimen S2 containing 30 wt% red mud and 40 wt% fly ash sintered at 1150°C had the better performances. It had the water absorption of 18.18%, open porosity of 38.52%, bulk density of 1.29 g/cm³, compressive strength of 42.46 MPa, and heat conductivity of 1.24 W/m·K. X-ray diffraction analysis indicated that mullite, anorthite, α-quartz, and diopside ferrian were the dominant phases in the specimens. Scanning electron microscopy micrographs illustrated that plenty of open pores with strip shape and closed pores with axiolitic shape existed in the specimens. Furthermore, the existence of mullite could prevent crack propagation to enhance the energy of inter-granular fracture. It endowed the porous anorthite ceramics with high porosity, good compressive strength, and low heat conductivity.     

油井土、废玻璃基多孔陶瓷的制备及结构表征

利用油井土、废玻璃作为主要原料,同时以碳酸钙作为造孔剂,通过控制烧结过程,最终制备多孔陶瓷材料,并利用XRD、SEM等对样品进行结构表征。本研究的目的是为了研究油井土、废玻璃、碳酸钙的比例以及烧结温度对孔隙率、机械强度、体积密度、吸水率、微观结构和结晶程度的影响。结果表明样品A3呈现大孔均匀的微观结构,是通过添加35wt％油井土、40wt％废玻璃、20wt％碳酸钙、5wt％硅酸钠在较低的烧结温度下来获得,其孔隙率、抗压强度、抗弯强度、体积密度和吸水率的值分别为52．38％、4．43 MPa、12．59 MPa、1．07 g／cm3和29．56％。并观察到其机械强度、吸水率和微观结构（孔径及孔径分布）有良好的相关性。     

Performance study of foam ceramics prepared by direct foaming method using red mud and K-feldspar washed waste

In this study, foam ceramics were prepared via a direct foaming method at high temperatures (1080–1120 °C), using red mud (RM) and K-feldspar washed waste (KFW) as the raw materials and SiC as the foaming agent, respectively. The chemical compositions and crystalline phases of the raw materials as well as the structural and mechanical properties of the foam ceramics were investigated. By adjusting the formulation and sintering process parameters, the porous structure of the foam ceramics could be effectively modulated. In addition to some residual crystalline phases in the raw materials, new phases, including rutile (TiO₂) and anorthite (CaAl₂Si₂O₈), were generated in foam ceramics. The compressive strength of the foam ceramics decreased with an increase in the KFW/RM ratio and sintering temperature, which was mainly related to the low density of the foam ceramics and the poor support of the pore walls to the structure. Among all the foam ceramics investigated, the foam ceramic with the KFW/RM ratio of 1:1, SiC content of 1 wt%, sintering temperature of 1100 °C and sintering time of 60 min showed the best overall performance with a bulk density, an apparent porosity, an average pore size and a compressive strength of 0.77 g/cm³, 61.89%, 0.52 mm, and 3.64 MPa, respectively. Its excellent porous structure and mechanical properties rendered it suitable for application as insulation materials or decorative materials for building partition walls.     

Effect of calcium carbonate on the preparation of glass ceramic foams from water-quenched titanium-bearing blast furnace slag and waste glass

ABSTRACT

Glass ceramic foams were fabricated with powder sintering technology at a low temperature (900°C), using water-quenched titanium-bearing blast furnace slag (WTS) and waste glass as the primary raw materials. Additionally, calcium carbonate, sodium borate and sodium phosphate were chosen as sintering aids to form excellent performance products. The effects of calcium carbonate additions on foaming process, crystal content, morphology and properties of the prepared samples were systematically researched. The research indicates that increasing the calcium carbonate content made the foaming process harder and the pore size got more uniform. Consequently, the compressive strength and bulk density increased, while the porosity and water absorption decreased. The homogenous porous structures and optimal comprehensive properties were achieved with 5–7?wt-% CaCO₃ addition, including a bulk density of 0.79–0.82?g?cm^–3, porosity of 73.13–75.28%, water absorption of 3.29–3.75% and compressive strength of 13.13–13.85?MPa.     

镍渣基泡沫玻璃的制备及其性能研究

以镍渣和废玻璃作为主要原料,使用Na2CO3为发泡剂,采用模具装填法来烧制泡沫玻璃.研究了镍渣的掺量、发泡剂掺量、发泡温度和发泡时间对泡沫玻璃的气孔结构和相关力学性能的影响.研究表明:镍渣掺量减少,Na2CO3掺量增加和发泡温度的升高,均会降低泡沫玻璃的体积密度,提高样品的平均气孔直径;镍渣掺量对泡沫玻璃的组成成分和晶体种类没有明显的影响;以20%镍渣和80%玻璃粉为主料,5%~7%Na2CO3为发泡剂,在发泡温度870 ℃下保温60 min,可以制备出气孔率为85.14%,体积密度为0.3715 g/cm3,抗折强度为2.062 MPa,平均气孔直径在3.13 mm的镍渣基泡沫玻璃.     

Recycling of lime mud and fly ash for fabrication of anorthite ceramic at low sintering temperature

Lime mud is a kind of waste generated during causticization reaction of an alkali recycling process in paper industry. Lime mud and fly ash were reused as raw materials to fabricate anorthite ceramics through solid state reactions. Both sintering temperature and lime mud content influenced the crystalline phases in the prepared ceramics. Anorthite was the major phase in all samples (samples L36, L40, L50 and L60) and it was prominent in sample L36 (containing 36 wt% lime mud). The results also showed that anorthite ceramic can be synthesized at low sintering temperature (1100 °C). Gehlenite and wollastonite were formed in the samples possessing higher calcium (above 40 wt% lime mud) or at lower sintering temperatures. Bulk density, water absorption and compressive strength were measured. These ceramics were of light weight and had high water absorption. Recycling of lime mud and fly ash as raw materials of anorthite ceramic is a feasible approach to solve the solid wastes.     

反应析晶烧结法制备硅灰石玻璃陶瓷

本文提出了一种直接利用废玻璃制备硅灰石玻璃陶瓷的新工艺:反应析晶烧结法。将高岭土和碳酸钙为主要原料合成的析晶促进剂加入到废玻璃粉末中烧结,通过两者间的反应析出硅灰石。研究了析晶促进剂含量和烧结温度对硅灰石玻璃陶瓷的组织、烧结和性能的影响,结果表明:随着析晶促进剂含量的增加,玻璃陶瓷的体密度和开孔隙率增加,强度先增后降。提高烧结温度促进反应析晶,并导致玻璃陶瓷的体密度、开孔隙率和强度降低。析晶促进剂含量为15%,烧结温度为850℃时,制得的硅灰石玻璃陶瓷的力学性能最佳。