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The purpose of this paper is to study the process of coprecipitation of polyhydroxocomplexes of nickel and aluminum from solutions of nickel (Ni) (II) sulfate and aluminum (Al) (III) sulfate with caustic soda and to study the conversion process to nickel aluminate and to check its properties.

For the thermodynamic analysis of the precipitation process, the software package MEDUSA was used. The dependences of the electrical conductivity, pH and residual concentrations as functions of the OH/Me ratio were obtained. Using X-ray phase analysis, spectroscopic analysis and derivatographic analysis, the properties of the products obtained were studied. The effects of OH/Me ratio and molar ratio cation of reagents on the physicochemical properties of the products were analyzed.

The paper deals with the results of theoretical and experimental research on the synthesis pigments of blue and green colors based on Ni-Al spinel. The influence of the molar ratio cation content on optical and color characterise of pigments were studied.

The original complex method of studying the processes of co-precipitation of cations in the form of hydroxides is proposed. pH precipitation of aluminum hydroxide and nickel are different. It is interesting to study their co-precipitation. The resulting single-phase product is a precursor of nickel aluminate over a wide range of cation ratios. The dependences of the electrical conductivity, pH and residual concentrations as functions of the OH/Me ratio were obtained.

The purpose of this paper is to conduct the directed synthesis of blue-colour aluminate spinel pigments based on spent aluminium–cobalt–molybdenum (ACM) catalyst and to study peculiar features of mineral formation processes and changes in their colour indices depending on composition and firing temperature.

Aluminate spinel ceramic pigments with specified colour indices were synthesised by directed formation of their mineral composition and identification of the most rational technological parameters of production. Mineral composition of synthesised pigments was evaluated by X-ray phase analysis. The colour indices of pigments and pigment-containing glaze coatings were studied on the comparator colour. The chemical resistance of pigments was determined by loss of their weight loss after boiling in 1 N hydrochloric acid solution and 1 N sodium hydroxide solution.

Peculiar features of formation of the mineral composition of aluminate spinel pigments based on the ACM catalyst were studied. The expediency of using magnesium and zinc oxides in their composition has been proved. It is found that for the formation of stable pigments of intense blue colour, a concentration of cobalt (II) oxide in the amount of 0.5 mol is sufficient, which is 23.1 Wt.%. The colour of such pigments is determined by the ratios of cobalt, magnesium and zinc aluminates, which form a spinel solid solution.

The use of developed aluminate spinel pigments provides obtaining of high-quality glass coatings of blue colour, in particular, for ceramics.

Aluminium oxide in the spent ACM catalyst is predominantly in the active form (of amorphous aluminium hydroxide and y-Al₂O₃). This is a prerequisite for the use of this waste material as a complete substitute for chemically pure Al₂O₃ in the technology of aluminate spinel pigments and reduction of their firing temperature. Besides, spent ACM catalyst already contains 5 Wt.% of expensive cobalt (II) oxide in the form of stable colour-bearing phase CoAl₂O₄.

This paper aims to introduce a novel approach to the fabrication of photoluminescent materials by coating rare earth aluminate luminescent materials on metallic substrates and a readily manufacturable light source with robust structure in the form of photoluminescent sphere (APS).

The clean and dried stainless steel sphere was sprayed with UH 2593, a white undercoat, the luminescent coating and the weather resistance coating in chronological order.

After adhered onto the stainless steel sphere, the peaks corresponding to the N-H stretching vibrations were changed. The intensity of free N-H stretching at 3,536 cm⁻¹ dramatically decreased and the peak of hydrogen-bonded N-H stretching of PU moved to lower wavenumbers. The red shift of the infrared bands of functional groups was attributed to the strengthened hydrogen bonding. The hydrogen bonding interactions between the stainless steel substrates and the polyurethane coating endowed the APS with excellent adhesive property and also promoted the evenly distribution of the photoluminescent particles in the polymer coating matrix.

This approach can be applicable in the fabrication of the photoluminescent materials. The APS can be used as signs and guiding post in remote areas without sufficient electricity supply and in the seas and rivers with complicated hydrological conditions.

This approach has provided a method to produce tough and durable luminescent signs for remote areas and dangerous seas and explained the functional mechanism of the combined application of metallic materials and non-metallic materials.

ZIRCONIUM Corrosion in hot water and steam. Metallic zirconium and its alloys have assumed much importance as construction and protection material in nuclear reactors cooled with water or heavy water. Among the properties favouring this application are low neutron absorption, favourable mechanical characteristics, and a high corrosion resistance to water and steam. This corrosion resistance can be further improved by using suitable zirconium alloys. Even so, there are still certain undesirable corrosion phenomena which cause trouble. These have been made the subject of further research, e.g. in the metal laboratory of the Metallgesellschaft A.G., Frankfurt‐am‐Main. In this connection, a distinction must be made between two phenomena which occur simultaneously but are, as far as it's known at present, basically independent of each other, viz. oxidation and hydrogen absorption. But the extent to which the hydrogen freed in the course of the oxidation process can be absorbed by the zirconium and thereby cause brittleness depends not only on the external conditions but also on the type and quantity of the alloying components. During oxidation, the slow formation of a thin, bluish oxide film is liable to be followed by a more rapid ‘breakaway’ corrosion process in which a white oxide is formed that will soon peel off. There is, as yet, no satisfactory theory which would appear to provide a full explanation of all the phenomena encountered. The author discusses the research methods, the corrosion phenomena as such, the influence of certain alloying constituents on these phenomena and the various attempts at interpreting them.—(H. W. Schleicher, Metalloberfläche, 1961, 15 (8), 234–240.)

The purpose of this paper is to study the patterns of formation of anti-corrosion properties, the development of compositions for pigments by using the method of co-precipitation and subsequent heat treatment.

To obtain co-precipitated hydroxides, aqueous solutions of salts were used. The conditions of synthesis varied according to the following parameters: the nature of the starting salts of metals; and the ratio of metal cations. The anticorrosive activity of the pigments was evaluated by the potentiodynamic method, by comparing the anodic and cathodic polarization curves, and calculated potentials and corrosion currents on the basis of regions of Tafel on curves. Polarization curves were obtained by using Potentiostat/Galvanostat/ZRA Gamry, which connected to the PC, and by using the program Gamry Framework. The measurement results were processed by using the method of simplex-lattice planning. X-ray diffractograms of pigments were recorded on a DRON – 2.0 diffractometer (monochromatic copper radiation with a nickel filter).

The paper deals with the results of research the dependence of colour characteristics and anticorrosion properties of synthesized compositions on their nature and composition. The presence of aluminium cations leads to the formation of solid solutions of ferrum and aluminium oxyhydroxides.

The main technological properties of pigments are determined by the anionic and cationic composition. Colour characteristics are determined by the cation-chromophore. The anti-corrosive properties of non-calcined pigments are determined to a greater extent by the presence of the formed hydroxyl ions and the composition of the compounds. The greatest protective effect is observed when using double compounds of metals, the dissociation constants of which differ significantly. The protective effect is mainly determined by the slowdown of the anode process. Anions containing aluminium atoms accelerate the corrosion processes.

Cement industry for both developed and developing countries is important from the economic point of view. It is playing a vital role in economic development of a developing country like Pakistan. However, these industries are posing threat to the environment, human health and plant species. The purpose of this paper is to identify the most critical factors of cement industry that have a negative impact on the environment, human health and plant species in the context of Pakistan.

The factors are categorized into air pollution, noise pollution, soil pollution, human health and plant species. These factors are categorized on the basis of previous literature and environmental safety reports. Air pollution is caused by iron and sulphur while noise pollution is mainly caused by crusher room and rotatory kiln end. The soil is being polluted by zinc and lead while human health and plant species are being damaged by sulphur dioxide and nitrogen dioxide. For the analysis purpose, a multi-criteria decision-making (MCDM) technique, i.e., decision-making trial and evaluation laboratory (DEMATEL) is used.

The result shows that the major cause of air pollution is “sulphur” while “crusher room and rotatory kiln end” are responsible for noise pollution. On the other hand, “mercury” is responsible for causing soil pollution while human health and plant species are influenced by the toxic effect of “nitrogen dioxide.”

The results obtained are specific to cement manufacturing industry of Pakistan and cannot be generalized for any other manufacturing sector.

The proposed methodology shows the most critical factors toward which concertation should be given for mitigating their impact. This study will help the government and the cement industry to focus on all those elements that are the most responsible for causing different types of pollution.

No such work is reported in previous research that proposes a framework using DEMATEL technique for analysis of critical factors of cement industries that have a dangerous impact on the environment and human health, especially in a developing country, like Pakistan.

Generally, of all the properties, corrosion resistance can be a prime consideration in determining whether a given alloy or metal is adequate for a proposed use. With the increasing ability to fabricate many alloys and metals into fibre material of extremely small diameter, a better knowledge of their chemical properties as related to their unique size becomes more essential since many of the potential applications involve exposure to corrosive environments. This article reviews the corrosion resistance of Brunsmet MF‐A1 stainless steel fibres produced by the Brunswick Corp., Chicago, Illinois.

GERMANY. Oxidation of refractory carbide alloys (hard metals). The effect of additions of tungsten, chromium and tantalum‐niobium on the oxidation rate and structure of the oxide layers was studied on samples of titanium carbide/cobalt bonded, and annealed at 800 to 1,100°C. for 75 hr. If these contain sufficient tungsten carbide to dissolve completely in titanium dioxide (rutile), the tungsten trioxide formed in oxidation, the rate of this latter decreases strongly owing to reduced ion diffusion. If, owing to the higher tungsten carbide content, the proportion of WO3 in the oxide layer becomes so high that the solubility limit for WO3 in TiO2 is exceeded, then CoTiO2, Co2TiO4 and C0WO4 occur in the oxide layer in addition to CoO and TiO2. This decreases oxidation velocity still more.

Corrosion cracking A metal fails due to corrosion fatigue if it cracks while being subjected to repeated or alternating tensile stresses in a corrosive environment. If the corrosive environment is removed, the metal will not fail through fatigue, even after a very high number of cycles, providing the tensile stress is below the fatigue limit.

Uranium‐nickel metal alloy. A binary alloy having the formula U6Ni is claimed to have corrosion resistance superior to U metal. The eutectic containing 37 atm.% Ni melts at 730° and is useful in the formation of more complex U alloys, where corrosion resistance is essential such as in the construction of atm. reactors. —U.S. Pat. 2,692,823, Marion E. Cieslicki and Benny J. Nelson.