USE OF NEPHELINE SYENITE IN FLOOR-TILE AND WALL-TILE BODIES*

The physical properties of wall-tile bodies and floor-tile bodies are described. The wall-tile bodies are fluxed respectively with nepheline syenite; feldspar; talc and feldspar; talc and syenite; talc, pyrophyllite, and syenite; and talc, pyrophyllite, and feldspar. Floor-tile bodies, developing at lower temperatures, may be formulated with nepheline syenite. The greater refractoriness of American clays used in these bodies, as compared to English clays, is compensated for by the increased fluxing action of nepheline syenite.     

USE OF SODA FELDSPAR IN WHITEWARE BODIES *

A comparative study is presented of a soda feldspar produced by a flotation process and of two potash feldspars when tested alone and made up in semivitreous and vitreous bodies. The investigation was divided into two parts, (1) a laboratory study and (2) plant trials on semivitreous dinnerware and on vitreous sanitary porcelain. From the results of the investigation, it was concluded that (1) it should be possible to substitute soda feldspar for North Carolina potash feldspar in semivitreous bodies containing not more than 12% feldspar, on an equal basis, with no significant change in properties except possibly crazing resistance; where crazing occurs, a slight modification of the regular glaze to give it a lower thermal expansion should correct the trouble; the formula of one modified glaze for this purpose is suggested; and (2) the substitution of soda feldspar for potash feldspar in sanitary porcelain and other similar vitreous whiteware bodies will doubtless require a reduction in amount in order to duplicate the vitrification and other properties of the potash-feldspar body in use; a modification of the regular glaze to fit the soda-feldspar body will probably be required; and the castability and control of casting slips should not be affected by the use of soda feldspar in place of potash feldspar.     

A comparison study of tialite ceramics doped with various oxide materials and tialite–mullite composites: microstructural,thermal and mechanical properties

Tialite (Al₂TiO₅) is a material of very low thermal expansion coefficient, high thermal shock resistance, high refractoriness and good corrosion resistance. However, its applications are very limited due to its low mechanical strength and to its thermal instability in the temperature range 750–1350 °C, which leads to the decomposition of the material to its parent oxides alumina and rutile. To overcome both problems, stabilization of the structure is tried through doping with various oxides; in the present work, a comparison study of the properties that can be achieved and of the decomposition behavior of tialite ceramics stabilized by adding MgO, talc or feldspar and of tialite–mullite composites made by the addition of kaolin is carried out. The processing conditions are also investigated for preparing porous ceramics for applications in the area of soot traps and hot gas clean-up. It was found that talc addition has an excellent stabilizing behavior, whereas tialite–mullite composites exhibit increased strength. Such composites with 10–20 wt.% mullite present the appropriate properties for the applications under consideration. Mullite presence also brings a stabilizing effect, thus in combination with talc additions it could lead to a very stable product.     

INVESTIGATION OF FELDSPAR AND ITS EFFECT IN POTTERY BODIES*

The history and purpose of the investigation are outlined and reports are made on (1) fineness determinations, chemical analyses, softening range, softening points, “true” specific gravity, thermal expansion, and petrographic analyses of the individual feldspars; (2) the results of porosity, volume shrinkage during firing, color and translucency, mechanical strength, petrographic analyses, effect of feldspar used on relative “glaze fit,” thermal expansion, and elasticity determinations on vitreous and semivitreous bodies in which feldspar is the only variable component.     

Properties of polycarbonate/acrylonitrile‐butadiene‐styrene/talc composites

The morphology, tensile, impact properties, and thermal expansion behavior of polycarbonate (PC)/acrylonitrile‐styrene‐butadiene (ABS)/talc composites with different compositions and mixing sequences were investigated. From the studies of morphology of the PC/ABS/talc composites, it was observed that some talc particles were located in both the PC and the ABS phases of the blend but most were at the interface between the PC and ABS phases for every mixing sequence. Aspect ratios of the talc particles determined by TEM image analysis reasonably matched values computed from tensile modulus using composite theory. The thermal expansion behavior, or CTE values, was not significantly influenced by the mixing sequence. The impact strength of the PC/ABS/talc composites depended significantly on the mixing sequence; a premix with PC gave the poorest toughness. The molecular weight of the PC in PC/talc composites was found to be significantly decreased. It appears that the impact strength of the PC/ABS/talc composites is seriously compromised by the degradation of the PC caused by talc. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Mode of talc addition and its effect on the properties of ceramic bodies

Raw and precalcined talc were added to feldspar to produce low temperature firing mixes. The feldspar content was kept constant, 25%, while talc was added in the range from 5 to 15% at the expense of quartz. Mixes were fired between 1150° to 1400°C. The results show that there is no significant difference in the properties obtained for the fired bodies whether talc is added raw or in a precalcined state. The addition of raw talc favoured the formation of cordierite in low-addition (5%–10%), while addition of precalcined talc favoured its formation in high-addition (15%). The mode of talc addition affected the form and shape of enstatite and cordierite grains developed.     

THERMAL AND MOISTURE EXPANSION OF KAOLINS AND BODIES FIRED TO DIFFERENT TEMPERATURES*

Thermal-expansion and moisture-expansion determinations were made on four kaolins of the Georgia, Florida, North Carolina, and English types alone and on typical semivitreous, hotel china, and electrical porcelain bodies embodying each of these kaolins after being fired at cones 6, 9, and 11. The Georgia and Florida kaolins and bodies showed surprisingly similar expansion characteristics. The general order of decreasing thermal expansion and increasing moisture expansion of the kaolins at all three firing treatments was Georgia, Florida, North Carolina, and English china. The semivitreous bodies at cones 6 and 9 showed the same order of expansion as the kaolins alone, but at cone 11 the thermal expansion of the English china clay body was the highest and the North Carolina kaolin body next in order. Moisture expansion of the bodies at cone 11 was found to be a function of the absorption, regardless of the kaolin used with no expansion obtaining at zero absorption. Mixtures of clay, flint, and feldspar, given an autoclave treatment after being fired to cones 6 and 9, showed that feldspar additions increased moisture expansion. When these mixtures were dehydrated at different temperatures, the data obtained were insufficient to confirm any theory on the nature of moisture expansion in a porous ceramic body.     

废弃石英坩埚资源化制备方石英质瓷

以废弃石英坩埚、苏州土、长石和铝矾土等为原料制备方石英质瓷。采用XRD、SEM、热膨胀仪和材料试验机等测试方法,研究了配方组成和烧成温度对方石英质瓷的物相组成、微观形貌和机械性能影响规律。结果表明：当配料配方中废弃石英坩埚40％、苏州土40％、钾长石15％和铝矾土5％,在烧成温度1300℃、保温时间30 min条件下,可以获得机械性能较佳的方石英质瓷,其弯曲强度为76．45 MPa,热稳定性△T ≥180℃,热膨胀系数为7．16×10－6℃－1（ RT～600℃）。     

采用普通陶瓷原料制备低成本多通道堇青石质陶瓷微滤膜

采用高岭土、铝矾土、滑石等普通天然原料,利用挤压成型法和浸渍提拉法制备了低成本多通道堇青石质陶瓷微滤膜。同时采用扫描电子显微镜、X射线衍射仪等对膜样品的显微结构及性能进行表征。结果表明,在1200℃下烧成,可成功制备孔隙率为28.2%的多通道堇青石质陶瓷微滤膜载体。然后通过浸渍提拉法,在固含量为25 wt%、浸渍时间为10s的工艺下,制备了厚度约为80μm的堇青石质顶膜。同时,实验制备的微滤膜还具备热膨胀系数低、结构均匀无缺陷和耐碱性能良好等优点。     

添加钾长石对镁掺杂钛酸铝陶瓷烧结及热膨胀行为和抗弯强度的影响

以镁掺杂钛酸铝固溶体粉体为原料,钾长石为烧结助剂制备了具有较高强度的低膨胀钛酸铝陶瓷.用场发射扫描电子显微镜观察了钛酸铝陶瓷断口形貌,并测量了陶瓷的烧结密度、抗弯强度和热膨胀曲线,研究了钾长石的引入量对钛酸铝陶瓷的烧结行为、微观结构、力学性能和热膨胀行为的影响.结果表明:钾长石的引入促进了镁掺杂钛酸铝陶瓷的烧结.引入8...     

铝钒土含量对低膨胀高远红外瓷质卫生陶瓷性能的影响

采用煤矸石废料、劣质原料黑滑石和铝钒土为主要原料,通过原位生长法制备了堇青石质低膨胀高远红外瓷质卫生陶瓷。利用XRD、SEM和性能测试研究铝钒土含量对堇青石卫生陶瓷性能的影响。实验结果表明:铝钒土含量对吸水率、抗折强度和膨胀系数具有较明显的影响,而对远红外辐射率并未带来不利的影响,所有样品的远红外率均保持在0.93以上。当铝钒土含量为27%,煤矸石33wt.%,黑滑石37%时,陶瓷性能达到最优:吸水率为0.04%,热膨胀系数为2.74×10-6/℃,抗折强度为87.4 MPa。这主要是由于样品的主晶相堇青石含量最高,并且烧结致密化程度高,其中气孔分布更加均匀所致。相关研究结果对环境保护和工业废物的资源化利用有着积极意义。     

FACTORS INVOLVED IN PRODUCTION OF THIN WALL TILE*

A study was made relative to the dry pressing of wall tile having a thickness of ³/₁₆ in. Three bodies, a high talc, a high pyrophyllite, and a regular body were studied. The water content was kept constant and the forming pressures were varied from 1000 to 3000 lb. per sq. in. The bodies were fired to cones 4, 6, and 8. The bisque tile were tested for thermal expansion, warpage, absorption, shrinkage, impact strength, transverse strength, and moisture expansion. The glazed tile were tested for warpage, impact resistance, and moisture expansion. The results showed that satisfactory thin wall tile could be made from all bodies, the high-pyrophyllite body indicating the greatest promise. It was found that pressing pressures had definite effects on impact strength, warpage, shrinkage, and thermal expansion.     

卫生陶瓷钙质无光釉的研究

本试验通过调整卫生陶瓷釉浆中的Si/Al，引入滑石和无光剂，成功地制备出卫生陶瓷钙质无光釉。同时本文还研究了Si/Al和滑石对无光釉无光性能的影响。     

Synthetic Ni‐talc as filler for producing polyurethane nanocomposites

New synthetic Ni‐talc was used as filler in the synthesis of polyurethane (PU) nanocomposites by in situ polymerization and to emphasize the contribution of the new material compared with natural talc. Good dispersion of Ni‐talc was supported by homogeneous green coloration observed in the polymer matrix. X‐ray diffraction (XRD) analyses indicate the intercalation of polymeric matrix into the filler layers by the increase in d₀₀₁‐spacing value of the Ni‐talc for the nanocomposites when compared to the pristine filler. The nanocomposites obtained with synthetic talc showed an improvement in the crystallization temperature and in thermal stability when compared to pure PU and the composite obtained with natural talc. The young modulus of PU/talc materials containing both Ni‐talc and natural talc were slight higher than pure PU. As shown by scanning electron microscope (SEM), Ni‐talc fillers were well dispersed into the polymeric matrix probably due to the good compatibility of both phases filler/polymer mainly achieved by the filler OH interaction with the urethane group of the polymeric chain. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41854.     

Nepheline syenite-talc low temperature vitrified bodies

Compositions in the system, talc-nepheline syenite-quartz-china clay (Kaolinite) were studied. The content of nepheline syenite was kept constant, 25%, while talc was added in the range of 5–15% at the expense of quartz. This study extended the range of fusible talc/nepheline mixes from 15 to 28%. The content of talc dissolved in the glassy phase is limited to 3–4%. Addition of talc to the compositions caused the dissolution of mullite and increased the glassy phase. The addition of nepheline syenite counteracts the effect of talc on the thermal expansion coefficient of the bodies.     

中温裂纹釉的研究

本文以钠长石、石英、硅灰石、方解石等为主要原料,采用正交实验法制备了一种中温裂纹釉,并探究了配方组成对冰裂纹釉面效果的影响。研究结果表明：坯、釉的膨胀系数差值大,是釉面开裂的重要影响因素。当坯体的膨胀系数为6.52×10-6/℃,釉的膨胀系数为7.29×10-6/℃时,可获得良好的冰裂纹釉。     

INFLUENCE OF VARIABLE AMOUNTS OF NEW YORK TALC,FLINT, AND CALCINED CLAY ON SERVICEABILITY OF GLAZÉD COOKING-WARE BODIES*

The effect of composition on the ability of glazed dishes to withstand thermal-shock treatments ordinarily received in cooking was studied. Bodies which gave best results contained approximately 10% of New York talc and also a small amount of calcined clay substituted for potters' flint. Bodies which had sufficiently high thermal expansion to throw the glaze into moderate or strong compression gave the best results. A terra sigillata finish applied to talc-free bodies was found to withstand autoclave treatment without crazing, and ware so made stood up very well in service tests.     

EFFECT OF WATER IN EXPANDING CERAMIC BODIES OF DIFFERENT COMPOSITIONS1

The effects of the composition of some ceramic bodies on their moisture expansions were investigated. With the exception of mixtures containing blast-furnace slag or magnesite, most bodies with high absorptions developed considerable expansion. Bodies with low absorptions composed of pure clay and feldspar developed practically no moisture expansion while those composed of clay, feldspar, and more than 20% silica developed considerable moisture expansion. By adding magnesite, the resistance of a ceramic body to moisture expansion was improved. Additions of whiting, iron oxide, and titanium oxide were not as beneficial as magnesite. It was found that crazing caused by moisture expansion of bodies can usually be prevented by proper manufacturing control.     

高透光细瓷的制备

实验以锂瓷石、石英、龙岩高岭土、钾长石、烧滑石为主要原料制备坯体,通过采用外加腐殖酸钠和膨润土来调节高透光细瓷坯体的成形性能;并通过单因素和正交实验考察了配方组成对高透光细瓷性能的影响。当配方（质量％）为：锂瓷石40、石英27、龙岩高岭土32、钾长石8、烧滑石1．5、膨润土2、熔块2、腐殖酸钠0．8、氧化铝2,在还原气氛1320℃烧成,制备了高透光细瓷。该细瓷透光度可达27．5。     

TALC AS A FLUX FOR HIGH TENSION INSULATOR PORCELAINS1

MgO has some possibilities as a partial or total flux in high tension insulator porcelains. To be practical for this purpose it must be introduced into the body through some cheap material which will not make a large percentage of calcine necessary. Talc seems to fulfill these requirements better than other sources of MgO more commonly used. A typical high tension insulator body of the general formula 0.21 K₂O, 1.0 Al₂O₃, 4.45 SiO₂ was used as a standard. The experimental work consisted chiefly in the partial replacement of the K₂O by MgO, the RO being varied between 0.14 and 0.30 equivalents. Talc was used as the source of MgO. The bodies were fired to temperatures ranging between cones 9 and 11 and were tested in most cases only for absorption and transverse strength. The results at cone 10½ indicate (1) a small addition of talc greatly decreases the percentage of feldspar necessary for vitrification, (2) additional small amounts of talc have much less effect than the first small addition, (3) about 0.16 equivalents of Ro are needed for vitrification at this temperature when small percentages of talc are used. This corresponds to about 15 to 22.5% of feldspar and about 2.5% to 0.75% of talc, (4) in the properly vitrified bodies the addition of the MgO at the expense of the K₂O, within the limits tested, tends to increase the transverse strength. Vitrified bodies of this general type show little improvement, if any, over regular triaxial porcelains. The writer recommends as the next logical step a trial of the effect of the replacement of feldspar entirely or almost entirely by talc and the use of higher temperatures to obtain vitrification.