化学发泡法制备钙长石系轻质隔热砖坯体

本文以高岭土、鲁山土、叶腊石、石灰和矿渣粉为主要原料,采用化学发泡法制备钙长石系轻质隔热砖坯体,再经高温煅烧进而制备钙长石系轻质隔热砖.在实验室条件下研究了发泡剂用量、料浆流动性和碱性激发剂的掺量等对化学发泡法浇注工艺和干坯抗压强度的影响,并借助于XRD分析了烧结体的物相组成,借助于光学显微镜观察其孔结构.结果表明,控制发泡剂用量6％,料浆水固比0.52,减水剂掺量1.5％,碱性激发剂用量0.5％,借助于化学发泡法,可以制得干坯容重350 kg/m3左右的轻质隔热砖坯体,干坯抗压强度可达0.55 MPa.由此制得的坯体在1340℃下保温2h后可以得到容重为500 kg/m3,抗压强度达到1.25 MPa的钙长石系轻质隔热砖.XRD分析表明,烧结体以钙长石相为主晶相,并有少量刚玉相;光学显微镜观察表明,烧结体内部显示发达而均匀分布的封闭圆形孔隙,平均孔径约700μm.     

泡沫胶凝法制备轻质钙长石耐火材料的工艺研究

以煅烧矾土、煅烧高岭土、硅灰石、蛋白质发泡剂、明胶、聚乙烯醇、硅溶胶和聚合硫酸铝为原料,采用泡沫胶凝法制备了轻质钙长石材料,主要研究了蛋白质发泡剂加入量、明胶加入量、硅溶胶和聚合硫酸铝的加入时机以及硅溶胶加入量等对泡沫胶凝成型工艺的影响,并分析了烧成后轻质钙长石材料的物相组成、显微结构和性能。结果表明:1)蛋白质发泡剂-水泡沫体系中蛋白质发泡剂的体积分数为15%时,体系的发泡倍数达到最大;每100 mL蛋白质发泡剂-水泡沫体系中加入1.2 g明胶时,泡沫的沉陷率最小,稳定性最好;将聚合硫酸铝促凝剂分散到黏稠泥浆中,制成泡沫泥浆后,在高速搅拌下按1 L泡沫泥浆加入137 mL硅溶胶的比例缓缓加入硅溶胶,搅拌结束15 m in后体系发生胶凝。2)按试验确定的最佳工艺成型并于1 280℃保温0.5 h烧成后的轻质钙长石材料,以钙长石为主晶相,并有少量刚玉相;烧成后的轻质钙长石材料为多孔结构,其气孔多为封闭气孔,且分布较均匀,平均孔径约200μm;烧成后的轻质钙长石材料的性能参数已达到,有的甚至已超过德国的Jm23砖。     

煅烧制度对合成轻质微孔莫来石骨料性能的影响

各类工业窑炉和热工设备的隔热保温是节能的重要方面。使用轻质耐火材料是实现节能的有效方法。开发和应用高性能轻质不定形耐火材料对实现节能意义重大。研制具有优良隔热性能的耐火骨料对开发高性能轻质浇注料有重要作用。以工业氧化铝、硅石粉为主要原料,采用加入可燃物的方法制备莫来石轻质合成料。根据坯体料的DSC-TG和大试样热重分析设置了不同的煅烧制度,比较了两种煅烧制度：一为单调升温,然后保温;另一为在高低两个温度分段保温。研究了两种煅烧制度对合成轻质微孔莫来石骨料莫来石化率及体积密度、气孔率性能的影响。结果表明,无烟煤约在600℃烧失,坯体料自1200℃开始发生莫来石化反应,试样经1350℃×6h热处理后的孔径分布3-7μm左右,莫来石转化率60%。     

烧成温度对钙长石隔热耐火材料显微结构与性能的影响

本工作以矾土水泥与黏土为原料,采用发泡法制备了钙长石隔热耐火材料,通过XRD、SEM和导热仪等分析了烧成温度(1 110～1 310℃)对钙长石隔热耐火材料显微结构与性能的影响,并研究了该种钙长石隔热耐火材料的合成机理。结果表明：当烧成温度为1 110～1 160℃时,体系内开始生成钙长石,但原料微颗粒间的反应并不完全,生成的液相含量较少,强度较低;当烧成温度为1 210～1 260℃时,液相含量增多,钙长石的生成速度加快,强度增大,试样具有较低导热系数;当烧成温度为1 310℃时,液相含量迅速增多,线收缩率迅速增大,试样具有较大强度,但体积密度大幅增长,气孔率降低。在1 260℃时,制得了体积密度为0.53 g/cm³、气孔率为82.6%、抗折强度为1.15 MPa、耐压强度为1.99 MPa、800℃导热系数为0.101 W/(m·K)的钙长石隔热耐火材料。     

钙长石涂层预应力增强建陶瓷砖

采用方解石、石英、氧化铝原料制备钙长石涂层,通过调控涂层的组成对坯体产生压应力来提高陶瓷弯曲强度。研究了料浆黏结剂种类、涂层中的Al_2O_3含量、弹性模量、涂层与基体的截面比等因素对涂层制备及陶瓷弯曲强度的影响。结果表明:当涂层配方中Al_2O_3含量为17.5%(质量分数)、1%PVA作为黏结剂、烧结工艺为1 200℃保温0.5 h时,可获得厚度约80μm的钙长石涂层,制得的陶瓷样品硬度为630 kg/mm~2,弯曲强度从(62±3) MPa提升至(107±4) MPa,提升幅度为72.6%。     

煅烧制度对合成轻质微孔莫来石骨料性能的影响

以工业氧化铝、硅石粉为主要原料,采用加入可燃物的方法制备莫来石轻质合成料。根据坯体料的DSC-TG和大试样热重分析设置了不同的煅烧制度,比较了两种煅烧制度:一种为单调升温,然后保温;另一种为在高低两个温度分段保温。研究了两种煅烧制度对合成轻质微孔莫来石骨料莫来石化率及体积密度、气孔率性能的影响。结果表明,无烟煤约在600℃烧失,坯体料自1200℃开始发生莫来石化反应,试样经1350℃×6h热处理后的孔径分布3￣7μm左右,莫来石转化率60%。     

高强度的泡沫玻璃

轻质泡沫玻璃系煅烧均匀混和过的玻璃细粉(100份,重量比)和粘士与发泡剂(40～100份)制得。这种泡沫玻璃具有良好的加工性能和隔音、隔热、防水、耐蚀等能力;它可用作为隔热或衬里材料。 100份(重量比)的玻璃细粉、70份钾——斜发     

膨胀珍珠岩保温材料及其应用

膨胀珍珠岩是将天然珍珠岩矿石（属酸性较大的玻璃质岩石，系火山喷发岩浆急冷浓缩而成的天然硅铝质无机非金属材料），经过破碎筛选，在高温煅烧下，其体积急剧膨胀，制得的多孔、色白的颗粒状物质。由于高温下导热系数低（0．05～0．15kcal／m·h·℃），耐火度〉1250℃，容重小（40-280kg／m^3），被广泛用作轻质保温隔热材料。     

含钛高炉渣还原提取钛硅合金后尾渣制备钙长石-尖晶石轻质多孔材料研究

以含钛高炉渣提取硅钛合金后的尾渣为主要原料,采用发泡法制备了钙长石-尖晶石质轻质多孔材料.研究了尾渣的物相组成,尾渣和朔州土及石英加入量、发泡剂、促凝剂、稳定剂、煅烧温度等工艺参数对材料物相组成、气孔率、体积密度以及孔径分布等性能的影响.结果表明:提取硅钛合金后尾渣的主要物相为铝酸一钙(CA)、二铝酸一钙(CA2)、镁铝尖晶石(MA)以及少量钙铝黄长石(C2AS);多孔轻质材料的主晶相为钙长石,含有少量镁铝尖晶石;多孔轻质材料的显气孔率可以稳定控制在75％左右,体积密度控制在0.35～0.85 g/cm3之间;适宜的烧成制度为1300℃×3h.     

粉煤灰陶粒制备试验研究

粉煤灰是燃煤电厂排出的主要固体废物,粉煤灰主要用于混凝土添加剂,附加值较低.为了提高粉煤灰的利用价值,本研究利用粉煤灰制备轻质高强陶粒.在1100 ℃煅烧时,粉煤灰陶粒烧结出现新物相钙长石,在1200 ℃煅烧时,石英相溶解到烧结物相中,粉煤灰陶粒烧结出现新物相普通辉石,煅烧温度控制在1100~1200 ℃范围较适宜.煅烧温度增加到1200 ℃时,筒压强度达到6.3 MPa左右,体积密度达到1.6 g/cm3左右.当P值较低时,粉煤灰陶粒的烧成温度降低,陶粒容易烧胀,当P值超过10时,粉煤灰陶粒的烧成温度过高,粉煤灰陶粒不易发生膨胀.     

Anorthite insulating refractory

Conclusions A technology was developed for manufacturing heat-insulating refractories with an anorthite composition and an apparent density of 0.3–0.4 g/cm³ or more using kaolin, semihydrated gypsum and stabilized foam. The proposed method guarantees a reduction in the production cycle, yielding cheap insulating brick, and the possibility of mechanizing the production processes.Anorthite ultralightweight refractories in terms of their basic factors correspond to insulating products made by foreign concerns for service at 1100–1260°C.Translated from Ogneupory, No.5, pp. 36–40, May, 1970.     

Anorthite ceramic materials

Translated from Steklo i Keramika, No. 12, pp. 10–12, December, 1990.     

Low-Temperature Fabrication of Anorthite Ceramics

Fabrication of anorthite ceramics suitable for low temperature, sinterable, multilayered substrates is described. Anorthite ceramics were synthesized from relatively pure kaolin and calcites of varying particle sizes. Mixed powders were uniaxially pressed and fired between 900° and 1200°C. Firing at 1000°C yielded a dense anorthite ceramic when the finest calcite powder was used. The relative density and water absorption of the anorthite ceramic were 94% and almost zero, respectively. Mixtures containing coarser calcite had lower densities and higher water absorption.     

钙长石陶瓷生坯片的制备

采用正交实验方法讨论了固相含量、增塑剂和粘结剂含量对水基流延成形钙长石陶瓷生坯片性能的影响,制备出厚度适宜的钙长石陶瓷生坯片,其强度、结构均匀性和柔韧性均能满足使用要求。     

Crystallization of Pseudo-orthorhombic Anorthite on Basal Sapphire

Anorthite-glass films were grown on basal Al₂O₃ substrates using pulsed-laser deposition. The substrates were cleaned and annealed in air at 1400°C to produce crystallographically flat (0001) terraces. The films were deposited in an oxidizing environment. X-ray microanalysis confirmed the composition of the glass films to be close to that of anorthite (CaO·Al₂O₃·2SiO₂). Although anorthite usually has triclinic symmetry, subsequent crystallization of these films in air at 1200°C resulted in the formation of pseudo-orthorhombic CaAl₂Si₂O₈ ( o -anorthite), a known metastable form of the mineral. Microstructural characterization was performed using visible-light microscopy, scanning electron microscopy, and transmission electron microscopy. The films dewetted the substrate either before or after crystallization to form o -anorthite islands which had strong orientation relationships to the Al₂O₃ substrate. The epitaxy of the o -anorthite islands was accompanied by a small lattice mismatch parallel to the substrate plane. The formation of three orientational variants is consistent with the symmetry of the basal Al₂O₃ surface. The dislocation network observed at the o -anorthite/Al₂O₃ interface indicates that nucleation and growth of the anorthite occurs directly on the substrate surface without an intervening interfacial amorphous layer. The study of anorthite-glass films is important because they are present in liquid-phase-sintered Al₂O₃, and may be devitrified by postsintering heat treatments.     

Low-Temperature Synthesis of Hexagonal Anorthite via Hydrothermal Processing

Hexagonal anorthite (CaAl₂Si₂O₈) has been prepared by hydrothermal processing of monocalcium aluminate and quartz at temperatures as low as 200°C. The successful development of this phase is dependent upon several processing parameters, including the hydration of the calcium aluminate precursor material to the hydrogarnet phase (Ca₃Al₂O₆·6H₂O) prior to hydrothermal treatment and the use of quartz as opposed to amorphous sources of SiO₂. Quartz has partial solubility in the hydrogarnet lattice for additions up to 40 wt%. Increased SiO₂ substitution has been shown to reduce the conversion of hydrogarnet to Ca₄Al₆O₁₃·3H₂O, thereby increasing its thermal stability and improving its strength characteristics at temperatures greater than 200°C. Quartz additions greater than 43 wt% lead to the formation of CaAl₂Si₂O₈ as the sole reaction product. The moderate temperatures involved in forming this anhydrous material are an order of magnitude lower than those necessary to form this phase by melt crystallization, making it a true chemically bonded ceramic. The reaction can form a bonded matrix with strengths up to 40000 psi (280 MPa). Strengths are limited due to density changes during anorthite formation, but the matrix is thermally stable up to 1000°C.     

钙长石／玻璃复合材料的制备和性能研究

采用电子陶瓷工艺制备了一系列钙长石／玻璃复合材料,并对复合材料进行X射线分析、扫描电镜观察和性能测试。结果表明：复合材料的介电常数、热膨胀系数随钙长石含量的增加而增加,而介电损耗和抗折强度随钙长石含量的增加而减小。钙长石含量大于50wt％的复合材料中α-石英和方石英的析出增加了材料的热膨胀系数,但对材料的介电性能影响不大。所制备的复合材料具有低的介电常数（5．4～6．1）、低的介电损耗（0．11％～0．41％）、低的热膨胀系数（4．3×10^-6～6．1×10^-6／℃）和低的烧结温度（≤900℃）,有望用于电子封装领域。     

Anorthite lightweight refractories for service in carbon-containing media

Conclusions The authors have developed a procedure for making anorthite lightweight artifacts with an apparent density of 0.5 g/cm³ and a low iron oxide content, permitting their service in carbon-containing reducing media up to 1300°C.Translated from Ogneupory, No. 7, pp. 40–42, July, 1980.     

Fabrication of Lightweight Anorthite Bodies from Lithomargic Clay

Lightweight anorthite bricks were fabricated by firing lithomargic clay with varied lime content. Mfensi clay was added as a binder, while sawdust was added to control porosity. The effect of lime on firing shrinkage, bulk density, apparent porosity, water absorption, and compressive strength of the anorthite bricks was investigated. Increasing lime content decreased firing shrinkage from 12% to 2% upon addition of 40 wt% lime. The bulk density and apparent porosity ranged from 0.77 to 0.96 g/cm³ and 45 to 56%, respectively. Water absorption was between 46 and 73%, while compressive strength was between 0.2 and 1.2 MPa.     

环境友好的泡沫注凝法制备钙长石多孔陶瓷

以碳酸钙、α-氧化铝和二氧化硅为原料、明胶作为凝胶剂,采用泡沫注凝法制备了系列钙长石多孔陶瓷,研究了明胶添加量对制备材料组成、结构与性能的影响.结果表明:明胶添加量对物相组成没有影响,均获得了单相材料;但对材料性能有一定的影响,当明胶添加量由6％(质量分数)增加到12％时,总气孔率由89.7％缓慢降低到88.0％,体积...