煤矸石-粉煤灰基发泡陶瓷的制备与性能研究

以北方某地区煤矸石、粉煤灰作为主要原料,以膨润土、废小苏打作为辅料,碳化硅微粉作为发泡剂,采用粉料堆积法制备了发泡陶瓷板材。对煤矸石、粉煤灰、发泡剂的加入量以及烧成制度进行了研究。结果表明:煤矸石、粉煤灰的加入量分别控制在35%和40%,膨润土5%,废小苏打2%,石英石18%,烧成温度1180℃保温30min可以制得性能优异的发泡陶瓷,其体积密度503 kg/m~3,抗压强度8.35 MPa,孔隙率65.3%,表观孔径0.5～1 mm。     

粉煤灰制备高强发泡陶瓷的研究

实验利用山西某地区产量较多的粉煤灰及其陶瓷厂产量较大的抛光渣作为主要原料,辅以钾钠砂、滑石来助融,加入膨润土增加料浆黏度,以碳化硅微粉作为发泡剂,在固定的耐火匣钵采用粉料堆积法制备高强发泡陶瓷。本研究在前期大量且品种各异废料制备发泡陶瓷的基础上,主要针对性的对粉煤灰、发泡剂的加入量。结果表明:粉煤灰加入量控制在50%,抛光渣15%,钾钠砂27%,膨润土5%,滑石3%,碳化硅微粉0.3%,烧成制度1180℃保温50min,制得性能优异的高强发泡陶瓷,体积密度为433kg/m3,抗压强度7.65MPa,孔隙率71.5%,表观孔径0.5mm-1mm。     

高硅铁尾矿制备轻质闭孔泡沫陶瓷研究

以辽宁抚顺铁尾矿为主要原料,黏土、高岭土、钾长石和钠长石作为辅助原料,SiC为发泡剂制备保温泡沫陶瓷。实验采用控制变量法和外加法,研究铁尾矿、助熔剂、发泡剂等原料配方和烧成温度对泡沫陶瓷体积密度、吸水率和抗压强度的影响。研究结果表明,在掺量分别为铁尾矿55%、高岭土18%、黏土18%、钠长石1.8%、钾长石7.2%时,外加剂碳化硅0.4%,烧成温度为1160℃时,获得了以闭口气孔为主的泡沫陶瓷试样。该陶瓷样品的孔径分布均匀,体积密度为0.600 g/cm3,吸水率为3.95%,抗压强度为7.65 MPa。     

MnO2对钼尾矿基发泡陶瓷升温速率影响的研究

随着发泡陶瓷社会需求的增多,采用固体废弃物烧制发泡陶瓷成为了研究热点.但关于如何缩短烧成周期,提高生产效率的研究寥寥无几.研究采用商洛钼尾矿为主要原料烧制发泡陶瓷,加入氧化剂MnO2,弥补发泡剂由于氧气不足而引起的发泡不均.在相同升温速率下,加入MnO2可使发泡陶瓷的平均孔径明显增大.在满足使用要求的条件下,将高温段的升温速率从3℃/min提高到5℃/min,缩短烧成周期约45 min,提高发泡陶瓷生产效率.     

建筑和石材尾料制备轻质发泡陶瓷板及其性能研究

建筑和石材尾料均属于硅铝质工业固体废弃物，若处置不当会污染环境。因此，本文开展了以建筑渣土、花岗岩石粉以及建筑陶瓷废料作为主材、绿硅（SiC）微粉作为发泡剂制备建筑用轻质发泡陶瓷板的研究，通过体积密度、抗压强度、抗折强度、导热系数和物相组成等方面的对比分析，寻找最优配方体系以及与之匹配的烧成制度。研究结果表明，建筑渣土、花岗岩石粉和建筑陶瓷废料重量占比分别为30%、45%和25%、绿硅加入量为0.19%、锰矿粉加入量为0.2%、烧成温度为1196℃/1180℃、烧成周期为15.75 h的条件下，能够制备出符合GB/T23451-2009标准要求的轻质条板。     

双氧水发泡法制备泡沫陶瓷外墙保温板

本文以粉煤灰和铜尾矿为主要原料,掺加膨润土和赤泥,以长石为助熔剂,双氧水为发泡剂,聚乙烯醇为稳泡剂,采用浆料发泡烧结法制备泡沫陶瓷外墙保温板.确定了适宜的原料组成为粉煤灰40％％铜尾矿38％％长石10％％膨润土10％％赤泥2％％双氧水的加入量为5％％所制备的泡沫陶瓷的性能为:吸水率0.90％％体积密度1.10g/cm3、显气孔率为0.70％％抗压强度为8MPa、导热系数为0.15 W/m·k.     

利用黄金尾矿制备发泡陶瓷的研究

中国黄金尾矿资源量大,作为二次资源在建筑材料领域的综合利用有着重要的经济价值和环境意义。以黄金尾矿为主要原料,SiC为发泡剂,通过高温制备发泡陶瓷,用激光共聚焦显微镜、XRD等手段,研究了烧结温度、黄金尾矿掺入量、原料粒度对材料的容重、真气孔率和孔径等性能的影响。研究表明:随着烧结温度的升高,发泡陶瓷材料的真气孔率和孔径增大,容重减小;材料的真气孔率和容重随着黄金尾矿掺入量的增大分别降低和提高,随着原料粒度的减小分别提高和降低,气孔孔径随着黄金尾矿掺量的增大和原料粒度的减小均呈下降趋势。优化后,在烧成温度1 050 ℃,黄金尾矿掺入量50%(质量分数),黄金尾矿平均粒度D(50)=5.6 μm,SiC平均粒度D(50)=3.0 μm的条件下可制备出性能良好的发泡陶瓷。     

低温快烧发泡陶瓷保温板的性能研究

本文通过调节发泡陶瓷保温板的烧成温度和烧成时间,分析两者对发泡陶瓷保温板的主要性能指标(干密度、吸水率、导热系数、抗压强度)的影响,综合各项性能的最优组合以及生产节能的目标,最终确定最佳烧成温度为1160℃、烧成时间50 min。     

不同掺量细铁尾矿砂对钢渣基蒸压加气混凝土性能的影响

为了提高铁尾矿的资源利用率，本文研究了细铁尾矿替代部分钢渣作为原料制备蒸压加气混凝土的可行性。本文通过改变细铁尾矿的掺量，研究不同配合比下细铁尾矿对蒸压加气混凝土的pH值、流动度、发泡性能、抗压强度和干密度的影响。采用X射线衍射、傅里叶变换红外光谱、热分析法、扫描电子显微镜分析以及孔隙结构分析，探究蒸压加气混凝土的矿物组成、微观形貌和孔结构。结果表明，加入细铁尾矿可以降低料浆的pH值，增加料浆的流动度，抑制料浆的发泡过程，同时细化了孔径结构，提高了样品的抗压强度。细铁尾矿的加入提高蒸压加气混凝土的性能，抗压强度的增加主要是托贝莫来石和硬石膏协同作用所致。     

高效隔热保温陶瓷材料的研制

以建筑抛光砖原料为基础料,添加少量的矿化剂和氧化镁,经干压成型后于1220℃-1300℃烧成下制备了具有防水、保温功能的闭孔高温发泡陶瓷.运用XRD、显微镜测试手段对发泡陶瓷的孔径分布、显微结构、物相组成进行了表征,探讨了原料配方、烧成制度对制品的主要性能,如:导热系数、吸水率、密度和强度的影响.结果表明,发泡陶瓷的气孔率高达66.72%(闭孔气孔率为66.39%,开孔气孔率为0.33%);体积密度为0.7987g/cm3,吸水率为0.41%;抗压强度为10.89MPa;导热系数为0.198W/(m·K);主晶相为石英和莫来石;且孔径和气孔率随着烧成温度升高而增大,气孔率越高,发泡陶瓷的抗压强度和导热系数越小.     

Utilization of gold tailings for the construction of foamed ceramics used in external insulation buildings

The utilization of gold tailings and bentonite as raw materials for prepared foamed ceramic was studied. The effects of boric acid and titanium dioxide content on the properties and microstructures of foamed ceramic were studied from the aspects of bulk density, compressive strength, bending strength, phase composition, and micromorphology. These results show that the synergistic effect of boric acid and titanium dioxide leads to the crystallization of quartz, which enhanced the compressive strength and bending strength and decreased the thermal conductivity of foamed ceramics, while the bulk density increases gradually with the addition of titanium dioxide. Taking into account all of these properties, the optimal results are as follows: bending strength of 1.111 MPa, compressive strength of 1.165 MPa, bulk density of 0.258 g/cm³, the porosity of 81.89%, the thermal conductivity of 0.088 (W/(m⋅K)). This study indicated that gold tailings are a promising candidate for the preparation of foamed ceramics used as external insulation building materials.     

Effect of Ca and Mg on the properties of foamed ceramics prepared with multisolid waste

With vanadium tailings and lead-zinc tailings as the main raw materials, gold tailings, waste glass powder, other fluxes and SiC foaming agents are added to prepare foamed ceramics. The effects of Ca and Mg in the fluxes of calcite, talc, and dolomite on the appearance, pore size, porosity, bulk density, and compressive strength of the samples were investigated and the mechanisms of the effects were analyzed. The XRD results showed that the sample consisted primarily of quartz, albite, augite, and a small amount of corundum. Calcite favors the formation of the augite phase, talc favors the formation of the albite phase, and dolomite combines the advantages of both. The formation of albite reduces the viscosity of the melt, and the formation of augite greatly enhances the strength of foamed ceramics. It has been shown that by adding 8% dolomite, a foaming ceramic with a bulk density of .561 g/cm³, a porosity of 62.77% and a compressive strength of 10.823 MPa can be prepared, resulting in a low-cost, lightweight and high strength foamed ceramic partition.     

The preparation of mullite foamed ceramics reinforced by in-situ SiC whiskers and their reinforcement mechanism

A SiC whisker-bonded mullite foamed ceramic was prepared by using white clay, industrial alumina and silicon powder as raw materials without solid carbon sources. The XRD, SEM, EDS, and Factsage® software were used to investigate the effect of sintering temperature on the phase composition, microstructure, compressive strength, and Young's modulus of foamed ceramics. Additionally, the synthesis reaction of in-situ SiC whiskers and the effect of their formation on the properties of ceramics were studied. The results showed that the in-situ SiC whiskers with dendrite shapes were formed after firing above 1300 °C at the expense of Si/SiO vapors as well as CO vapor, though there were no solid carbon sources in raw materials, which provided a new idea for the synthesis of SiC whiskers. The formation of SiC whiskers was helpful for improving the compressive strength and Young's modulus of mullite foamed ceramics remarkably. Furthermore, the reinforcement mechanism has been investigated systematically.     

尾矿制备气泡混合轻质土的力学与抗冻性能研究

以尾矿制备气泡混合轻质土,研究了湿密度和尾矿质量掺量对轻质土力学和抗冻性能的影响,并研究了尾矿对轻质土气孔结构的影响。结果表明,气泡混合轻质土的抗压强度与湿密度成正相关,与尾矿掺量成负相关。当尾矿掺量达到45%(质量分数,下同)时,湿密度为700 kg/m³和800 kg/m³的轻质土抗压强度分别为0.97 MPa和1.40 MPa,相比未掺尾矿的轻质土强度分别下降约69%和66%。尾矿制备气泡混合轻质土具有良好的抗冻性,30次冻融循环中,湿密度为700 kg/m³尾矿掺量为0%~45%的轻质土抗压强度损失率均在15%以内,且抗压强度均大于0.80 MPa,提高湿密度等级可以进一步改善轻质土的抗冻性。尾矿的掺入会导致轻质土孔隙率和平均孔径增大,孔圆度降低,相比于未掺尾矿的轻质土,当尾矿掺量达到30%时,孔隙率增大3.58%、平均孔径增大16.7%、圆度值增加7.4%。     

碱激发-碳养护对铜尾矿固化砖的作用机理研究

以细粒级铜尾矿作为主要原材料,水玻璃为激发剂,辅以少量水泥和粉煤灰,通过碱激发反应、压制成型及碳养护制备铜尾矿固化砖。采用X射线衍射、热重-差示扫描量热法、压汞法和扫描电子显微镜-能谱仪等对试样的物相组成、碳化产物、孔隙分布和微观产物形貌进行分析,探讨碱激发-碳养护对铜尾矿固化砖性能提升的影响规律。结果表明,水玻璃可以激发铜尾矿的部分胶凝活性,生成更多絮凝状C-S-H凝胶,改善铜尾矿固化砖的微观孔结构进而提升其抗压强度。碳养护的时机选择至关重要,固化砖成型后立即进行碳养护,碳化反应会与碱激发反应竞争OH^-,生成文石型和方解石型CaCO₃,导致C-S-H凝胶的生成量减少,孔隙率增大,抗压强度降低。固化砖密封养护84 h后再碳养护84 h,其7 d抗压强度可提高20.9%,碳化产物CaCO₃填充内部孔隙,有害孔和多害孔数量大幅减少,无害孔数量增加,整体结构密实程度提高,从而解决铜尾矿固化砖表面泛霜的问题。     

利用黄金尾矿制备陶瓷清水砖的研究

为了实现黄金尾矿高效资源化利用,以黄金尾矿为主要原料,采用无压烧结制备了陶瓷清水砖样品,研究了黄金尾矿添加量对样品相组成、显微结构及性能的影响。结果表明,当烧成温度为1 100 ℃,黄金尾矿添加量为70%(质量分数)时,样品性能最优,其抗折强度达73.42 MPa,吸水率为0.10%,气孔率为0.25%,体积密度为2.46 g/cm³,烧成收缩为8.64%,达到GB/T 4100—2015《陶瓷砖》中瓷质砖的要求。样品的相组成为钙长石、石英、白榴子石和赤铁矿。清水砖坯釉结合性好,釉面光滑,色泽均匀。     

Some technological laws and properties for highly porous ceramic concretes

Conclusions Using ceramic concrete made from zirconia as an example we formulated conditions and established the main technological laws for obtaining highly porous ceramic concretes.We analyzed the composition and microstructure of the ceramic concrete from the point of view of the existence in the system of noncompensated shrinkage. It is shown that for ceramic concrete with a high bond shrinkage during drying and heat treatment, with the purpose of reducing the shrinkage stresses in the system, it is necessary to use multifraction (coarse, medium, and fine) fillers.We show the effectiveness of using, as one of the filler components, removable poreforming additive, based on foamed polystyrol.The optimum region of the grain-size distribution of the components was established; this comes within the true specific volumes in the structure of the shaped ceramic concrete and amounts to 20–30% bond, 20–25% fine (0.1–0.4 mm) and 25–40% coarse (5–10 mm) filler made from waste zirconia foamed ceramics, and 20–25% foamed polystrol (0.63–1.6 mm).We studied certain properties of the resulting materials with a porosity of 60–75% and a compressive strength of 5–20 MPa.Compared with other highly porous materials, for example, foamed ceramics, the highly porous ceramic concretes have technological advantages (much lower water capacity of the shaping system, reduced shrinkage in drying and firing) and also improved operating characteristics, for instance, thermal conductivity, thermal-shock resistance and volume constancy.Translated from Ogneupory, No. 2, pp. 20–25, February, 1984.     

New consolidation process inspired from making steamed bread to prepare Si3N4 foams by protein foaming method

A new consolidation process had been developed for preparing Si₃N₄ ceramic foams by using protein foaming method, which was inspired from the preparation of steamed bread. The main advantage of this consolidation process was no crack development during foamed slurry consolidation process. By using this new consolidation, Si₃N₄ ceramic foams with open porosities of 79.6–87.3% and compressive strength of 2.5–22 MPa were prepared. Protein addition and solid content on mechanical properties and pore structures of the as-prepared ceramic foams were investigated. Results indicated that the open porosity decreases with protein addition and solid content while compressive strength increased with solid content. With the increase of solid content, pores of the ceramic foams became regular in shape and uniform in size while both size and number of windows on the walls decreased.     

粉煤灰发泡陶瓷的制备及性能研究

面对日益匮乏的陶瓷原料,利用固体废弃物来制备发泡陶瓷已是当今趋势。以粉煤灰为主要原料,研究铬渣掺量、碎玻璃掺量和粉磨工艺对粉煤灰发泡陶瓷的影响。结果表明,掺入适量的铬渣可改善粉煤灰发泡陶瓷的性能,小掺量的碎玻璃对粉煤灰发泡陶瓷的性能影响较小。当原料配比为m(粉煤灰)∶m(铬渣)∶m(长石)∶m(碎玻璃)=60∶10∶20∶10时,采用湿法粉磨3 h,可以制得平均孔径为0.64 mm,体积密度为368.54 kg/m³,抗压强度为8.11 MPa的发泡陶瓷。     

利用珍珠岩工业尾矿低温快烧制备轻质陶瓷砖的研究

本文以珍珠岩工业尾矿为主要原料,加入适量炼铝赤泥、发泡剂和减水剂,采用低温快烧工艺可制备既有装饰效果,又有隔热保温功能的轻质陶瓷砖产品。实验结果表明:珍珠岩尾矿适合用于低温快速烧成的主体材料;赤泥中CaO、Na2O、Fe2O3含量较高,可以显著降低烧成温度。