Showing papers on "Sodium silicate published in 1985"

Hot Corrosion of Sintered α‐Sic at 1000°C

Abstract: The hot corrosion of sintered alpha-SiC by thin films of Na2SO4 and Na2CO3 was studied at 1000 C in controlled gas atmospheres. Under all conditions, corrosion led to 10 to 20 times the amount of SiO2 formed in pure oxidation after a 48-h exposure. In addition, small amounts of sodium silicate formed. Melts of Na2SO4/SO3 caused uniform pitting of the SiC substrate; Na2CO3/CO2 melts caused localized pitting and grain-boundary attack. In all cases, the protective SiO2 layer dissolved to form silicate, leading to corrosion. In the sulfate case, free carbon in the SiC promotes this process. In all cases the presence of liquid films is responsible for rapid transport rates and the subsequent rapid reaction.

Process for the preparation of crystalline sodium silicates

Abstract: A process for the preparation of crystalline sodium silicates with a molar ratio SiO 2 /Na 2 O of 1.9:1 to 3.5:1 from amorphous sodium silicate is described. To water-containing amorphous sodium silicate with a molar ratio SiO 2 /Na 2 O of 1.7:1 to 3.75:1 and a water content of 5 to 95% by weight is added 0.01 to 30 parts by weight of the crystalline sodium silicate to be prepared (per 100 parts by weight of Na 2 O+SiO 2 in the water-containing amorphous sodium silicate). The reaction mixture is dehydrated by heating. The dehydrated reaction mixture is kept at a temperature of at least 450° C., but below the melting point, until the sodium silicate has crystallized.

Treatment of carbonaceous materials

Abstract: Hydrocarbon liquids are recovered from carbonaceous materials such as tar sands utilizing a separation reagent formed in situ by reacting polar resin components of tar sands with an inorganic base such as sodium silicate in sonicated aqueous solution in absence of an organic solvent to form a surfactant. Under the influence of sonication a microemulsion of polar-external micelles forms. The polar groups can associate with anions, especially polyanions such as silicate and act in a membrane mimetic manner to form vesicles. Cavities can form in the surfactant resin molecule that complex with guest cations such as titanium or other metals from the tar sand. When tar sands are added to the sonicated separation reagent, the surfactant penetrates the bitumen. Metal ions complex with the polar groups and aid in removing the bitument from the sand particles. The polarorganic asphaltene materials are carried into the aqueous phase by the anion and stabilized within the micelle structure. The lighter, non-polar hydrocarbon oil fraction separate from the emulsion and rise to the top and are recovered by skimming. The heavier asphaltenes and preasphaltenes complex with the polyvalent metals to form charcoal-like agglomerates which settle to the bottom of the treatment tank. The separation reagent forms during the reaction and can reach a concentration capable of dissolving bitumen. The separation reagent can be recovered and used in other processes after removal and recovery of the clay. The separation reagent must be substantially diluted after being recycled and reused to reduce solvation properties.

Crystalline magnesia-silica composites and process for producing same

Abstract: Novel aromatic alkylation catalysts are manufactured by an extended hydrothermal treatment of the precipitation product of a magnesium salt with sodium silicate in the presence of tetrapropylammonium bromide or related compound.

Zeolite containing heavy duty non-phosphate detergent composition

Abstract: A phosphorus-free heavy duty synthetic organic detergent composition of improved cleaning power which includes certain proportions of sodium linear higher alkylbenzene sulfonate, molecular sieve zeolite, preferably type 4A molecular sieve zeolite, percompound oxidizing agent which is either an alkali metal perborate tetrahydrate, an alkali metal percarbonate, an alkali metal carbonate peroxide or a mixture thereof, and sodium silicate of Na 2 O:SiO 2 ratio in the range of 1:1 to 1:3.2. Preferably, the product also includes higher fatty alcohol polyethoxylate detergent. The invented product demonstrates good soil removal properties when compared with similar products containing a pentasodium tripolyphosphate builder salt. Methods of laundering fabrics with the invented compositions are also described.

Method of making seed solution useful in zeolite catalyst manufacture

Abstract: The useful storage life of a clear solution of seeds used to initiate the crystallization of zeolite in porous microspheres of calcined clay is increased by adding sodium silicate solution to a matured seed solution.

High-resolution solid-state silicon-29 nuclear magnetic resonance spectroscopic studies of synthetic sodium silicate hydrates

Abstract: Etablissement d'un modele simple decrivant la structure des differents silicates de sodium hydrates

Hydrophilic film-forming agent for aluminum

Abstract: PURPOSE:To form hydrophilic films having superior characteristics on the surfaces of Al parts by treating the parts with an aqueous soln. contg. an alkali silicate, an inorg. hardening agent and a water-soluble org. high-molecular compound. CONSTITUTION:When hydrophilic films are formed on a heat exchanger made of Al or an Al alloy and fins fitted to the exchanger, the wettability with water is improved to prevent the formation of drops of water on the heat exchanger and the fins and to smoothen the circulation of a fluid. In order to form the hydrophilic films, a composition consisting of 1pt.wt. of an alkali silicate such as sodium silicate or potassium silicate, 0.1-5pts. inorg. hardening agent such as aluminum phosphate or magnesium phosphate, and 0.01-5pts. water-soluble org. high-molecular compound such as anionic addition polymer having carboxylic acid or carboxylate groups is dissolved in water as a hydrophilic film forming agent, and the Al parts are immersed in the resulting aqueous soln. Hydrophilic films having extremely superior performance are formed on the surfaces of the parts by 0.5-3g/m .

Fluid cracking catalyst and method of making same from waste catalyst manufacture fines

Abstract: An improved process for ion-exchanging sodium ions in particles containing sodium form zeolite crystals and sodium silicate. The process involves an initial ion-exchange at pH about 4.5 to 5.0 with an ammonium salt followed by exchange with an ammonium salt at about pH 2.0 to 3.5. Cracking catalysts having improved cracking activity are produced.

Process for preparing ZSM-5, large pore mordenite and ZSM-35

Abstract: A process for preparing porous crystalline alumino-silicates consisting of bringing into contact, in an aqueous environment, sodium silicate with an aluminum derivative at a molar SiO2 /Al2 O3 ratio greater than or equal to 8, in the presence of one or more alkaline hydroxides at a molar Me+ /SiO2 ratio greater than 0.6, where Me+ represents the alkaline metal or metals, and in the presence of a mineralizing agent, operating at a temperature of between 20° and 100° C., and controlling the molar OH- /SiO2 ratio of the resultant mixture at a value of 0.01 and 0.8, the resultant mixture being crystallized at said molar OH- /SiO2 ratio in a closed environment for a period of between some hours and 40 days at a temperature of between 100° and 200° C.

Method of preparing crystalline sodium silicates

Abstract: Beschrieben wird ein Verfahren zur Herstellung von kristallinen Natriumsilikaten mit einem Molverhaltnis SiO 2 /Na 2 O von 1,9:1 bis 3,5:1 aus amorphem Natriumsilikat. Disclosed is a process for the preparation of crystalline sodium silicates having a molar ratio SiO 2 / Na 2 O of 1.9: 1 to 3.5: 1 from amorphous sodium silicate. Wasserhaltiges amorphes Natriumsilikat mit einem Molverhaltnis SiO 2 /Na 2 O von 1,7:1 bis 3,75:. Hydrous amorphous sodium silicate having a molar ratio SiO 2 / Na 2 O of 1.7: 1 to 3.75 :. und einem Wassergehalt von 5 bis 95 Gew.-% wird vernetzt mit 0,01 bis 30 Gew.-Teilen des herzustellenden kristallinen Natriumsilikats (pro 100 Gew.-Teile Na 2 O+SiO 2 im wasserhaltigen amorphen Natriumsilikat). and a water content of 5 to 95 wt .-% is cross-linked with from 0.01 to 30 parts by weight of the crystalline sodium silicate to be prepared (per 100 parts by weight Na 2 O + SiO 2 in the water-containing amorphous sodium silicate). Die Reaktionsmischung wird durch Erhitzen entwassert. The reaction mixture is dehydrated by heating. Man halt die entwasserte Reaktionsmischung so lange bei einerTemperatur, die mindestens 450°C betragt, jedoch unter dem Schmelzpunkt liegt, bis das Natriumsilikat kristallisiert ist. Keeping the dehydrated reaction mixture as long as at a temperature that is at least 450 ° C but below the melting point, until the sodium silicate has crystallized.

Silica of high purity and production thereof

Abstract: PURPOSE: To produce low-radioactive silica of high purity, by precipitating silica from sodium silicate with a mineral acid containing a chelating agent and hydrogen peroxide in a specific concentration and washing the resultant precipitates with a mineral acid containing a chelating agent and hydrogen peroxide. CONSTITUTION: An aqueous solution containing sodium silciate (about 20wt% expressed in terms of SiO 2 ) is reacted with a mineral acid, e.g. hydrochloric acid or nitric acid, to form silica. In the above-mentioned method, the silica precipitates are formed in an acidic region at ≥1N acid concentration, in which a chelating agent and hydrochloric acid are present. A dicarboxylic acid, polycarboxylic acid, hydroxycarboxylic acid, aminopolycarboxylic acid or a salt thereof is used as the chelating agent, and the amounts of the chelating agent and hydrogen peroxide are respectively 0.1W5wt% based on SiO 2 . The resultant silica is then separated, recovered and washed with a 0.5W3N mineral acid containing a chelating agent and hydrogen peroxide to produce the aimed silica of high purity containing impurities as follows; ≤1ppm all the metallic elements and ≤1ppb U and Th respectively. COPYRIGHT: (C)1987,JPO&Japio

A process for preparing polymer particles

Abstract: Substantially spherical solid particles of a substantially uniform particle size are prepared by dispersing a solution of a polymerizable substance in a first liquid by means of a suitable emulsifier to form droplets of the polymerizable substance of a substantially uniform particle size, which are thereafter poured into a second liquid with which the first liquid is immiscible and which contains a sufficient amount of a reactant to polymerize the polymerizable substance. After the polymerization the substantially embodiment, an aqueous solution of an alkaline metal silicate, especially sodium silicate, is dispersed in a coparaffinate by means of a suitable emulsifier, and the emulsion is poured into an aqueous solution of the polymerization reactant to form gelled, substantially spherical hydrated silica particles.

Hydrothermal production of clear sodium silicate solutions

Abstract: A process for the hydrothermal production of clear sodium silicate solutions by reacting sand and aqueous NaOH solution wherein an excess of 5 to 10% by weight of sand is used and the reaction is conducted in a rotating pressure vessel until 90 to 95% complete, after which it is transferred and completes in a blow-off vessel.

Solubilities of carbon dioxide in sodium silicate melts

Abstract: Carbonate solubilities in Na2O-SiO2 melts were measured over the composition range XNa2O/ (XNa2O + XSiO2) = 0.5 to 1.0 and the temperature range 1100 to 1300 ‡C. The solubility increased with increasing XNa2O and decreased with increasing temperature. Carbonate capacities calculated from the experimental results compared favorably with values for sulfide and phosphate capacities obtained from the literature. In addition, an excellent correlation was obtained between carbonate capacity and the activity of sodium oxide. The carbonate capacity, which is an easier parameter to obtain, is a good measure of the basicity of sodium silicate melts. It would appear that carbonate capacity could be an excellent basicity index for iron and steelmaking slags as well as for fluxes used in other high temperature technologies.

Adsorption of sodium metasilicate on calcium minerals

Abstract: The adsorption characteristics of sodium silicate on scheelite, calcite, and fluorite minerals were investigated. Adsorption equilibrium took about 60 minutes. Adsorption data show that the Maximum amounts of adsorption of sodium silicate occurs at about pH 9.8. The adsorptivity was in the order of calcite > fluorite > scheelite. The amount of adsorption of sodium silicate increased with the increase in temperature of sodium silicate solutions. The amount of adsorption of sodium silicate decreases in the low concentration range of ferrous sulfate, while in the high concentration range of ferrous sulfate, the adsorption of sodium silicate increases.

In vivo corrosion of sodium silicate glasses

Abstract: Square-shaped implants of various sodium silicate glasses were weighed and implanted intraperitoneally in rat for periods ranging from 8 to about 60 days. The implants were then removed and their aspect was compared to their aspect before exposure to physiological environment. The corrosion products were studied by x-ray diffraction and electron microprobe analysis. Weight changes were also measured to calculate a biodegradation rate. The glass 66 SO (66.6 SiO2-33.3 Na2O) was strongly corroded, as early as after the first week. The nonsoluble degradation products formed a cocoon encapsulating the now smaller specimen. The analysis of the cocoon showed that it was made of a silica-rich layer containing also calcium and phosphorus. In this layer the ratio Ca/P could correspond to that of an apatite. The biodegradation rate reached 71 x 10(-4) g . cm-2 . day-1. The glass 75 SO (75 SiO2-25 Na2O) was not so quickly corroded: Cracks appeared at the surface and progressively reached the center of the implants. There was no removable shell but a white deposit, adherent to the surface. This deposit contained silica and also calcium and phosphorus at the periphery. The biodegradation rate was only 2.6 x 10(-4) g . cm-2 . day-1.

Crystalline silicic acid, its salts, and processes for their preparation

Abstract: Crystalline sodium silicates having a sheet structure and an ion exchange capacity of 83-130 mmol of Na + /mol of SiO 2 are prepared by a method in which an aqueous reaction mixture which contains sodium silicate, has a molar ratio SiO 2 /Na 2 O of 3.9:1 to 15:1 and a molar ratio H 2 O/(Na 2 O+SiO 2 ) of 3:1 to 80:1 and contains 0.01 to 30% by weight, relative to the amount of SiO 2 in the reaction mixture employed, of seed crystals of the desired crystalline sodium silicate is prepared, the mixture is heated to temperatures of 160° to 250° C., the reaction is carried out at least until, in the X-ray diffraction pattern of a sample filtered off under suction and dried at 120° C., the ratio of the intensity of the reflection at the interplanar spacing d 1 =(20±2)·10 -8 cm to the intensity of any reflection present at the interplanar spacing d 2 =(15.5±1.5)·10 -8 cm is at least 3:1, and the reaction is terminated before the intensity of the reflection at the interplanar spacing d 3 =(3.34±0.04)·10 -8 cm reaches or exceeds the intensity of the reflection at the interplanar spacing d 4 =(3.44±0.04)·10 -8 cm. A crystalline silicic acid having a sheet structure and the overall composition H 2 Si x O 2x+1 , wherein 15

High silica/alumina ratio faujasite type NaY

Abstract: A sodium Y type faujasite having a high silica/alumina ratio is obtained by lowering the active soda content below the conventionally employed levels. This is done by adding an acid and/or an aluminum salt solution such as an aluminum sulfate solution to the sodium silicate in the zeolite synthesis slurry. Alternatively, the desired alumina and silica starting materials can be supplied in part by using an aluminum salt gelled mother liquor such as an alum gelled mother liquor. This permits the use of less reactants which are high in soda such as sodium silicate and sodium aluminate which in turn reduces the amount of soda present. The addition of these soda removers or the use of low soda reactants permits the production of NaY having a silica/alumina ratio of 5.0 and higher. These Y zeolites have a high degree of crystallinity as measured by an NMR sharpness index defined herein and they have an absence of occluded silica. The final product can be ion exchanged to a low level of Na2 O with rare earth or other metal cations or ammonium ions, to make a more thermally and steam stable zeolitic promoter for catalysts for treating petroleum fractions than can be made from conventional sodium Y.

Building material and manufacture thereof

Abstract: A building material is produced by forming a moldable aqueous composition including intermixed portland cement, gypsum, sodium hydroxide, sodium silicate, water, particles of a metal or metals selected from the group consisting of aluminum and zinc, and preferably also sodium thiosulfate, shaping the composition to a desired configuration, and then drying it to a hardened porous condition.

Magnetic powder for synthetic resin magnet

Abstract: PURPOSE: To obtain the high oxidation-resisting powder having no deterioration in magnetic characteristics even in the high temperature environment of 150°C or above by a method wherein a film of silicic anhydride or silicate is provided on the surface of the magnetic powder, to be used for synthetic resin magnets, containing a rare-earth element, and a coupling agent or resin is coated on the surface of said powder. CONSTITUTION: The SmCO 5 obtained by performing a reduction diffusing method is put in an ethyl alcohol solution, and after it has been pulverized and formed into the average grain diameter of 10μm, it is dried up in a vacuum drying machine. Then, 30ml of sodium silicate solution of 165g/l in composition is added to 45g of the obtained SmCO 5 powder, they are fully agitated, and after they have been dehydrated and filtered, they are dried up again, and a sodium silicate film of 100W300Å in thickness is adhered to the surface of the grains. Subsequently, they are maintained at room temperature, 5vol% of resin is mixed, magnets are obtained by performing a compression-molding, and after a surface treatment has been performed using γ-aminopropyltriethoxysilane, a heat treatment is performed at 150W200°C. COPYRIGHT: (C)1987,JPO&Japio

Arc welding method of cr-mo steel for high temperature service

Abstract: PURPOSE:To obtain a high C-low Ti-V weld metal having excellent low-temp. toughness by using a high-basicity low hydrogen type welding rod which consists principally of CaCO3 metallic fluoride such as CaF2 or the like and contains TiO2 at the lower rate than in the prior art. CONSTITUTION:The component for the coating material of a coated arc welding rod is composed of the essential components consisting, by weight %, of 45-60 CaCO3, 10-25 metallic fluoride, 2-7 SiO2, 1.5-5 Si and 1-4 Mg and the components limited to =2 kinds among sodium silicate, potassium silicate and lithium silicate to manufacture a coated arc welding rod. Arc welding is executed by using such rod.

Treatment of magnesium or magnesium alloy

Abstract: PURPOSE:To impart sufficient corrosion resistance without generating public nuisance, by successively treating magnesium or a magnesium alloy with an aqueous solution containing a metal ion and a phosphate radical, an aqueous solution of alkali metal silicate and silicone. CONSTITUTION:Magnesium or a magnesium alloy is immersed in an aqueous solution containing a metal ion and a phosphaste radical such as an aqueous Ca (H2PO4) solution while the treated one is subsequently immersed in an aqueous solution containing alkali metal silicate such as sodium silicate and sufficiently washed with water and dried. In the next step, a diluted solution of an org. solvent souting containing a paint grade silicone resin is applied to the surface film obtained by the above mentioned treatments by an immersion or spraying method and, after drying, silicone treatment is applied. A strong film is formed to magnesium or its alloy by the above mentioned surface treating method and excellent corrosion resistance can be imparted and there is no possibility for generating public nuisance.

Development and effectiveness of a soluble manganese silicate compound in controlling manganese deficiency in plants

Abstract: A study was made of soluble manganese silicates prepared by adding a solution of manganese sulfate to different concentrations of sodium silicate in alkaline medium. The solubility of manganese increased with increasing amounts of sodium silicate and reached its maximum at a molar Na2SiO3/MnSO4 ratio between 10 and 15. At molar Na2SiO3/MnSO4 ratios of 5 and more a red-brown coloured manganese silicate is formed, which is stable in the pH range of 4 to 12. Gel chromatographic analysis indicated that this compound contains 1 molecule Mn per 15 molecules SiO2. At a molar Na2SiO3/MnSO4 ratio of 15 the yield of soluble manganese could be raised to 98.5% of the theoretical amount by preventing the rapid oxidation of the Mn2+-ions in the alkaline solution. A pot experiment with oats was conducted to evaluate the effectiveness of the red-brown manganese silicate in controlling manganese deficiency. The effect of the Mn-carrier on Mn-content and yield of grain and on the colour scores was compared with that of Mn-EDTA, Mn-DTPA and MnSO4·4H2O. The manganese silicate was found to be a more effective manganese source than Mn-EDTA, Mn-DTPA or MnSO4·4H2O.