THE MANUFACTURE AND PHYSICAL PROPERTIES OF DRY PRESS BRICK

The process of manufacture of dry press brick is described and physical differences between dry press and stiff mud brick are enumerated. The advantages of the dry press process are summed up as follows: (1) they are uniform in size and shape; (2) they have small spalling loss; (3) they have good fusion resistance; (4) their heat conductivity is less than brick made by other processes; and (5) they have a low rate of manufacturing costs.     

REFRACTORIES FOR OIL-GAS MANUFACTURE1

The present investigations of refractories by the oil-gas industry on the Pacific Coast were stimulated by sporadic independent tests in the past whereby it was observed that different qualities of fire brick not only had varying lengths of service but also had an apparent influence on the amount and quality of gas made and on the efficiency of gas manufacture. The essential differences in generator design, including that of brick-work construction, in the two-shell type of generator as compared with the single-shell generator are such that longer refractories life is obtained in the former type. The operations in the manufacture of oil gas for the two-generator types are briefly discussed, showing that the refractories are subjected to alternating oxidizing and reducing conditions. Other causes contributing to ultimate refractories failures are carbon deposition in the brick, abrasion of hot gases and the impinging of long flames on the brick, heavy checker-brick loads on arches, faulty construction of arches, and erratic working conditions. In addition, super-saturated steam, heavy hydrocarbons, and salts and sulphur in the oil, are contributing causes to checker-brick disintegration, especially in the generator zones where the oil and steam are introduced. It is hoped that specifications for refractories may be drawn up from the results of practical service tests now being conducted. The heat-transfer and heat-absorption properties of various refractories, such as conductivity, specific heat, density, diffusivity, heat capacity, and time required for the refractories to reach near-heat saturation, are discussed, particular attention being given to their possible application as oil-gas generator checker brick. The need for more complete and accurate data on the fundamental constants necessary in heat-transfer calculations is pointed out. Researches on refractories with thermal properties superior to fire brick are now being conducted in generators in an endeavor to increase gas capacity and operating efficiency along the lines indicated by theoretical considerations.     

熔融法制氮磷钾肥的试验研究

以尿素、磷铵、氯化钾为原料,进行了配料熔融、原料粒度及原料加入顺序试验,探索其熔融条件对物料熔融的影响及变化规律,研究了配料比与熔融温度的关系,获得尿素磷铵氯化钾的熔融温度图,可作为选择配料与熔融温度的重要依据。     

PHASE-EQUILIBRIUM DATA IN THE MANUFACTURE OF REFRACTORIES*

It has been possible, with certain types of refractories, to apply phase-rule data to the manufacturing processes. The fields in which these data are useful include silica, magnesite, chrome, dolomite, forsterite, and, to a limited extent, alumina-silica refractories. Phase-rule data frequently are inadequate, and in other cases their use is dependent on certain empirical generalizations. Refractories usually contain five or more oxides which are present in amounts that cannot be ignored. The application of three-component phase-rule data is possible because of independent research conclusions which have shown that there is almost no solubility of certain components in the liquid phase in some systems or that one or more components are present almost entirely in solid solution. In predicting which of several types of refractories is likely to succeed best in a given service, the information available is usually insufficient to permit a strict application of phase-rule data. Slagging action, in a large measure, depends on slag viscosity, and viscosity data are usually not available.     

一步合成法硬脂酸盐的投产和应用

介绍了合成树脂使用的稳定剂、润滑剂—硬脂酸盐的一步合成法生产过程;对一步合成法和复分解法进行了比较;还列举了一步合成法生产的硬脂酸盐的应用情况。     

METHOD FOR THE ANALYSIS OF ALUMINOUS SILICATE REFRACTORIES1

A method is given in which the solution of difficultly fusible refractory material is obtained by subjecting the finely pulverized material to two fusions, the first in sodium carbonate, followed by one in potassium bisulphate. The melts are dissolved in water and after adding sulphuric acid are evaporated to dense fumes. Care is taken to remove any calcium sulphate that may be formed. The final residue is treated with hydrofluoric and sulphuric acids. The alumina is determined according to the method described by Blum as given by Hillebrand especial care being used in heating the final precipitate to constant weight. A temperature of about 1150°C is necessary. Two precipitations are required in the determination of lime. The excess of ammonium salts are removed prior to the precipitation of the magnesia, by adding an excess of nitric acid, evaporating to dryness and heating, which expels the ammonium chloride according to the reaction NH₄Cl + HNO₃= HCI + 2H₂O + N₂O.     

行星球靡干法制备煤超细粉研究

通过大量的实验,对行星球磨干法制备煤煤超粉进行了研究,并讨论了对影响粉煤出料粒径的主要工艺,确定最佳粉碎条件,并在数理分析与计算基础上总结出粉煤粒径与球煤比、粉碎时间、进料粒度的线性关系,为超细粉制备技术及粒径预报提供了一定的理论依据。     

行星磨干法制备硅酸锆超细粉研究

本文对干法制备硅酸锆超细粉进行了研究。通过大量的实验,对影响粉碎效率的主要因素进行了讨论,确定粉碎效率的最佳条件,为提高硅酸锆超细粉制备提供了依据。     

采用加压-真空两段热缩聚法制备中间相沥青炭纤维的原料

以深度裂解石油渣油为原料，采用两段热缩聚法可制得软化点为268℃，可编性良好的中间相沥青。本文详细考察了温度，时间对中间相沥青软化点，可编性，中间相沥青形态及碳化收率的影响，并初步探讨了两段热缩聚反应的机理。研究结果表明反应温度，时间对中间相沥青的结构和性能影响较大，选择适宜石油渣油，采用加压－真空两段热缩聚法，调整反应条件，可制得可纺性良好的中间相沥青。     

OIL FIRING OF REFRACTORIES1

Notes on the construction and condition of kilns used for refractories, comments on the results obtained when firing with fuel oil, and data on the equipment and operation of the kilns, are discussed in this paper.     

环保型刚玉高光干粉涂料生产与应用

介绍了以802干粉黏胶剂为主要原料生产干粉涂料的原材料、配方、生产方法、性能及应用。     

THE THERMAL EXPANSION OF REFRACTORIES1

The thermal expansion or contraction of a number of typical refractories has been measured up to 1700°C in a neutral or slightly oxidizing atmosphere. In nearly every case the expansion curve has been carried to a higher temperature than given by previous data. In a few cases the expansion curve has been obtained for materials that have not been studied in this way before. It is believed that the expansion curve of a brick, if carried to the softening point, gives valuable information as to the performance of that brick in service.     

EXAMINATION OF POLISHED SPECIMENS OF REFRACTORIES BY REFLECTED LIGHT*

A discussion is presented of the preparation of the sample specimen and the polishing, etching, and identification of phases when the technique is applied to basic and silica refractories. This method shows the relationship of high-iron slag to tridymite and cristobalite in the silica brick and it aids in the explanation of the bursting of chrome-magnesite brick by iron oxide.     

THE ELECTRICAL RESISTIVITY OF REFRACTORIES1

The electrical resistivities of flint fire clay, kaolin, magnesite, sillimanite, silica, diaspore, Maryland, Italian and Indian talcs were determined at temperatures up to 1500°C. Tests were made in an atmosphere of nitrogen, by the Wheatstone bridge method, using 45-volt 1000 cycle alternating current. With the exception of magnesite, the rate of decrease of resistivity decreases with an increase in temperature. The investigation indicates that the resistivity of a complex ceramic body, especially if it is open and porous, is not constant for a given temperature above the temperature at which its most fusible mixture melts. Resistivity is affected by the amount of impurities present, decreasing with an increase of impurities. As was shown in the tests of Italian talc, the resistivity is not only dependent upon the amount of impurities, but also upon their distribution. Within the limits of the voltage used, the resistivity is independent of the potential applied.