PROPORTIONING THE GRAIN SIZE IN CLAY REFRACTORIES1

A brief review is given of previous work pertaining to proportioning of the particle sizes. Experimental work presented has to do with the proportioning of three sizes of flint clay. To the proportioned particle sizes there were added different amounts of plastic or bond clay. There are given the effects of proportioning upon density, porosity, and change during firing. Clays from two producing districts were used, and although the experimental work on these was comprehensive, similar work should be continued in plant-scale operations. The summary presents the benefits which may be expected from proportioning particle sizes of fireclay mixes used in refractories.     

THE DETERMINATION OF IRON IN GLASS SAND1

Data are presented in tabular form showing the determination of iron in the Bureau of Standards Sample of Glass Sand, No. 81. The electrometric titration method, the H₂S reduction method, and the gravimetric method are described in detail.     

吉安高岭土的除铁增白

分析了影响吉安高岭土煅烧白度的几个因素。简要介绍了高岭土矿中铁存在的几种形式,并阐述了利用物理和化学方法对高岭士除铁增白。     

氧化钴中钴快速测定

针对氧化钴中钴的测定,采用二甲酚橙为指示剂,ＥＤＴＡ为滴定剂测钴时,加入孔雀绿作衬托剂,可明显地改善滴定终点,使滴定终点灵敏,准确;建立了一种测定氧化钴中钴含量的简便、快速的分析方法,实际样品分析表明,其结果令人满意。     

METALLURGICAL REQUIREMENTS OF REFRACTORIES IN COPPER SMELTING AND REFINING1

The requirements of refractories in the copper industry may be classed as follows:

• 1 Resistance to temperatures
• 2 Resistance to chemical action
• 3 Ability to withstand sudden temperature changes
• 4 Minimum absorption of slag and metal
• 5 Absence of manufacturing defects.

     

DETERMINATION OF IRON IN GLASS SAND*

The 0-phenanthroline method for the colorimetric determination of iron has been adapted to the analysis of glass sand. The sample taken for analysis was decomposed by treatment with HF and H₂SO₄, followed by fusions of any insoluble material with Na₂CO₃ and finally with K₂S₂O₇. An aliquot was then adjusted to the proper pH by a simple procedure, the iron reduced by hydroxylamine hydrochloride, the 0-phenanthroline complex formed, and the transmittancy of the solution measured spectrophotometrically. The method is simple and rapid, and compares favorably in precision and accuracy with other available methods.     

氧化铁电极的半导体性能和光电化学 Ⅴ.烧结掺锌氧化铁电极的光电响应

Somorjai等曾报道在不同电势下,测得掺MgO氧化铁光电极具有n,p两种类型的光响应。最近本实验室首次报道了在同一电势下,热形成的掺MgO-Fe_2O_3光电极具有n,p型双重光响应共存现象,由于其在电催化等中可能的应用价值引起了较广泛的兴趣。本文对掺入ZnO的Fe_2O_3粉末压片高温烧结法制备的电极的光响应进行了进一步     

氧化铁析晶过程及烧成制度的探讨

通过理论分析与动态观察等试验方法研究了铁结晶釉中氧化铁的析晶过程，确定了“阶梯式”升温的烧成工艺制度，为铁系结晶釉的生产提供了一定的理论基础。     

铁离子掺杂对TiO_2的晶粒生长及晶化过程的影响

采用溶胶-乳化-凝胶法制备纯TiO2和Fe-TiO2复合体,通过热重-差热分析,X射线衍射和扫描电子显微镜对其热处理过程进行表征,通过晶粒生长动力和热分解反应分析,探讨了铁离子掺杂对TiO2晶粒生长和晶型转变的影响。结果表明:铁离子的掺杂使得TiO2在低温条件下的晶化过程加快,晶粒生长速度增大,晶型转变温度升高。其原因是纯TiO2和Fe-TiO2的晶粒生长表观活化能依次为25.179kJ/mol和27.431kJ/mol;热分解活化能分别为13.743kJ/mol和9.024kJ/mol。Fe对TiO2晶粒生长的阻遏作用和热分解活性增大。     

镧铁共掺杂二氧化钛纳米线阵列的可见光催化性能

采用溶胶-电泳沉积技术,在多孔氧化铝模板中合成了二氧化钛(TiO2)纳米线阵列结构.研究了La3 /Fe3 共掺杂对TiO2纳米线可见光催化性能的影响,并分别与La3 ,Fe3 单掺杂TiO2纳米线可见光催化性能进行了比较.结果表明:与La3 ,Fe3 单掺杂TiO2纳米线相比,La3 /Fe3 共掺杂TiO2纳米线具有更高的可见光催化活性,光照4 h对甲基橙的降解率就达到了90%以上,大幅度提高了Ti02的可见光催化活性,这是因为2种不同体系离子的协同作用,不仅有效抑制了光生电子和空穴的复合,而且明显降低了TiO2的禁带宽度,由3.24降低到2.38.研究还表明:TiO2纳米线阵列极大的比表面积以及表面特有的性质和结构是掺杂改性TiO2纳米线具有较高可见光催化活性的重要因素.     

氧化锡氧化铌共掺杂二氧化钛氧气响应特性的稳定性

研究了氧化锡(SnO2)、氧化铌(Nbb2O3)共掺杂二氧化钛(TiO2)作为厚膜用氧传感器材料的响应特性.X射线衍射分析表明:适量掺杂使厚膜晶粒保持金红石结构,晶胞参数有所增大.扫描电子显微镜显示:厚膜在1 280℃左右长时间(11 h)保温,晶粒仍保持适度尺寸.X射线光电子能谱分析表明;较低的Nb掺杂浓度导致晶粒表面产生高浓度金属缺位(Vm),低温端(300 ℃)的氢气响应时间变短;高温端(600 ℃)的氧气响应时间急剧增大.Nb掺杂浓度较高时,低温端(300 ℃)氢气响应时间变长;高温端(600 ℃)氧气响应时间变短,但仍保持着响应特性的稳定性.结果表明:用摩尔分数x(Sn)=2.31%,x(Nb)=0.48%的组分,既能在同一结构下适度增加晶胞参数,又能相应提高掺杂浓度,可获得工作温度范围(300～600 ℃)内灵敏度和响应速度长期稳定的厚膜材料.     

EFFECT OF COMPOSITION AND TEMPERATURE ON SOLUBILITY OF IRON OXIDE IN GROUND-COAT ENAMEL GLASS*

The solubility of iron oxide in ground-coat enamel glasses at various temperatures was studied by adding varying amounts of ferric oxide to the milled enamel and giving the mixture a heat-treatment to acquire uniformity without devitrification at the desired temperature. The iron oxide solubility was obtained by finding the breaking point in the curve for iron oxide versus index of refraction. The frit solubilities were obtained at 1400°, 1600°, 1800°, and 2000°F. with variations in Na₂O, B₂O₃, A1₂O₃, CaF₂, CaO, F₂, SiO₂, COO, NiO, MnO₂, BaO, and MoO₃. Data are given on a number of commercial frits.     

氟锆酸铵中ZrO_2的快速测定

研究了在ＨＮＯ３介质中ＥＤＴＡ快速测定氟锆酸铵中ＺｒＯ２的方法。对于高纯样品采用返滴定法测定,对于含有杂质的样品采用直接滴定法。上述方法所测结果与重量法结果相近,方法简单、快速。     

THE SOLUBILITY OF QUARTZ AND CLAY IN FELDSPAR1

The literature on the subject is completely reviewed. The method used involved the addition of increasing amounts of kaolin to fixed amounts of feldspar and the addition of increasing amounts of quartz to fixed amounts of feldspar. All compositions were examined microscopically and the presence of undissolved kaolin was shown by the appearance of mullite needles, while the presence of undissolved quartz was shown by the presence of cristobalite. Soda feldspar is a better solvent for both quartz and clay than potash feldspar. The solution of quartz in soda feldspar starts at about 1350°C and increases with the temperature until at 1425°C. 32 parts of quartz per 100 of feldspar are dissolved. The solution of quartz in high potash feldspar does not start until 1400°C and only 4 parts are soluble at 1425°C to every 100 parts of feldspar. The solution of clay in soda feldspar starts at 1225°C and increases with the temperature until at 1425°C thirty-six parts are soluble. The solution of clay in high potash feldspar starts at 1250°C and at 1425°C the solubility is 20.5 parts per 100 of feldspar. The solution of quartz in porcelain bodies starts at the same temperature as it does in the pure feldspar which the body contains. The amount of solution per unit of feldspar is much greater. The general trend of one of the boundary lines in the ternary system K₂O-A1₂O₃-SiO₂ has been found.     

透明氧化铁黄颜料的制备和表面改性

介绍了透明氧化铁黄颜料的性质、用途、制备方法以及改性处理。通过在反应过程中和/或反应结束后加入各种助剂处理,可得到透明度高、分散性好、色相纯、耐热性能优良的透明铁黄。     

火焰原子吸收光度法连续测定陶瓷颜料中的铬钴锰铁镍

研究了空气—乙炔火焰原子吸收光度法连续测定陶瓷颜料中的铬、钴、锰、铁、镍、氢氧化钾高温处理样品，方法简单、快速、准确，干扰元素少，方法标准偏差小于2．1％，回收率98—103％，相对标准偏差小于6．‰。