Interaction of titanium-containing metals with magnesia refractory concretes using water glass

Refractories and Industrial Ceramics - In contact with titanium-containing metals alloyed with aluminum under conditions of high temperatures (1730–1750°C) and high vacuum...     

Sea water desalination using glass hollow fibre membranes

Hollow fibre membranes suitable for the two-stage desalination of sea water have been prepared from phase-separable Na₂O-SiO₂-B₂O₃ glasses. The hollow fibres had outside diameters in the range 20 to 200 microns and corresponding wall thicknesses of 5 to 40 microns. The production of fibres from two glasses by means of phase separation, leaching and sintering is described. Using a 3.5% NaCl solution at 120 bars, product fluxes of about 1.0 m³/m²/day at 88% rejection were obtained with fibres of one glass, and fibres of the other glass withstood hydraulic compressive pressures over 200 bars. There was no evidence of compaction or hydrolytic degradation.     

Aluminosilicate concretes bonded with water glass

Summary A composition was developed for aluminosilicate concrete with a water-glass bond with a density of 1.25–1.30 g/cm³ and with a setting accelerator-Portland cement.By reducing the density of the glass and eliminating the addition of sodium silicofluoride, the RUL is increased by 300° C compared with ordinary concrete used at present. The concrete possesses a high strength over the entire temperature range, a high abrasion resistance and excellent spalling resistance.The technical properties of the fireclay concrete suggest that this material can be used at up to 1300° C, and the aluminous at up to 1450° C in place of piece aluminosilicate goods.To solve the problem of the reliable and mass use of the recommended concretes in heat exchangers and in other parts of rotary cement furnaces it is necessary to carry out extra tests with the concretes on a bigger scale.     

Preparation of glass-ceramics with low density and high strength using blast furnace slag,glass fiber and water glass

To reduce the production costs of glass-ceramics and broaden the application field of solid waste in steel industry, low-density and high-strength glass-ceramics were produced by using blast furnace slag as the basic material, choosing glass fiber and water glass as the strengthening agents. The effects of glass fiber and water glass on the phase composition, microstructure, apparent density, water absorption and compressive strength of glass–ceramics were investigated. The results show that the rod structure of glass fiber can be retained in the sintered samples and high content of diopside and augite significantly improve the compressive strength of glass-ceramics. Tiny spherical crystalline phases can be obtained for the glass-ceramics soaked in the moderate concentration of water glass. The BGW-2 samples fabricated with 70% blast furnace slag, 30% glass fiber and 4% water glass, exhibit excellent comprehensive properties. The bulk density, water absorption and compressive strength of BGW-2 are 1.76 g/cm³, 2.26% and 68 MPa, respectively. Consequently, using blast furnace slag to prepare glass-ceramics can be another applicable way to utilize blast furnace slag efficiently.     

Treating water for solid impurities using helical filter elements with dynamic perlite membranes

The work represents results of studying the process of creating dynamic perlite membranes on Krapukhin’s Filter Elements (KFEs). It has been shown that KFEs with pore sizes of 25–55 ?m are the most suitable for creating a perlite precoat layer. Test results of the installation based on four KFEs in advanced treatment of water for solid impurities at Mosvodokanal wastewater treatment facilities are represented. It has been shown that the application of KFEs with a dynamic perlite membrane allows one to treat water from solid impurities with an efficiency of over 98%.     

Spouting characteristics of small glass particles with water

Experimental data are reported for the minimum spouting velocity, bed pressure drop, maximum spoutable height and spout diameter which show that spouting of small particles with water represents a new spouting regime. The transition from large to small particle spouting occurs when the voidage at the inlet to the spout goes from unity to less than unity.     

Sol-Gel synthesis of an optical silica glass doped with rare-earth elements

An optical quality silica glass doped with Er³⁺, Yb³⁺ and Lu³⁺ ions is synthesized by the sol-gel method. Virtually unavoidable clusterization of rare-earth elements that occurs upon introduction of lanthanide salts into a sol-gel system and leads to concentration quenching of luminescence of the glass is eliminated through the use of rare-earth phosphate complexes that are chemically bound to the SiO₂ network. This makes it possible to obtain a nearly molecular distribution of rare-earth elements in the glass matrix.     

Supercritical water and particle nucleation: Implications for water chemistry control in a GEN IV supercritical water cooled nuclear reactor

One of the potential undesired processes in the heat transport system of the GEN IV Supercritical Water Cooled Reactor (SCWR) concept may be the formation of nanosize particles from ions present in the feed water or released in the coolant by corrosion products. Large-scale molecular dynamics simulations are being employed to investigate the nucleation and growth of salt nanoparticles in water over wide range of supercritical states. The particle nucleation rate in supercritical water appears to be on the order of 10²⁸ cm⁻³ s⁻¹, with critical nuclei having an amorphous structure. A molecular mechanism for possible hydrolysis reaction at supercritical conditions is examined.     

工业水玻璃制备SiO2/NR复合材料的研究

将超微细SiO2的制备工艺与天然橡胶（NR）的制备工艺相结合，以工业水玻璃为原料，采用溶胶-凝胶法制备SiO2溶胶和凝胶，再以天然鲜胶乳共沉-共凝制备SiO2／NR复合材料。实验结果表明：共沉-共凝法制备的SiO2／NR复合材料的综合力学性能明显优于机械共混法制备的复合材料；当SiO2质量分数为10％时，硫化胶的拉伸强度和撕裂强度分别比机械共混法制备的硫化胶提高了51％和49％，比纯NR硫化胶提高了88％和62％。复合材料拉伸断面电子扫描显微镜（SEM）观察表明，采用溶胶-凝胶法制备的超微细SiO2在NR硫化胶中的分散性较好，界面结合紧密，体现了超微细SiO2对NR具有较强的补强效果。     

Synthesis and application of a silica nanocomposite filler using water glass and a resole‐type phenol resin

Composite plastics in which silica was dispersed homogeneously were prepared from a resole‐type phenol resin and a silica‐sol using water glass. The silica (10–50 nm) was dispersed into resin particles of 2–20 μm in size. The powder that was obtained (nanocomposite filler) and a curing reagent were then mixed, and the resulting mixture was processed by using heat and pressure to yield plastics containing nanocomposite fillers. The coefficients of friction factor of the resulting plastics composites decreased by half and the amount of wear that they suffered decreased to just one tenth of that of the unfilled material, while their wear‐resistance was greatly improved. The new plastics displayed good sliding properties, while also maintaining good fluidity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009