CAS number：6834-92-0
molecular formula：Na2O3Si
molecular weight：122.06
EINECS number：215-687-4

English synonyms

SILICA STANDARD;SODIUM SESQUISILICATE;SODIUM SILICATE, META;SODIUM-M-SILICATE;SODIUM METASILICATE;SODIUM METASILICATE N-HYDRATE;WATER GLASS;DISODIUM TRIOXOSILICATE

Related categories

Silane Reagents; Catalysis and Inorganic Chemistry; General Reagents; Silicon; Silicates; Oxides; Organic Chemical Raw Materials; Chemical Products - Organic Chemicals; Inorganics; InorganicSalts; SyntheticReagChemicalbookents; ;Inorganic chemical raw materials;Sodium metasilicate;Inorganic salts;Inorganic acids;Additives;Chemical materials;Other;Chemical raw materials;Inorganic chemical products;Silicates

Introduction

Sodium metasilicate is a salt of silicic acid, which is an inorganic salt product with the molecular formula Na2SiO3 nH2O. It is a non-toxic, odorless and pollution-free white powder or crystalline particle. Alkaline, it is easy to absorb moisture and deliquescence when placed in the air. It has the functions of descaling, emulsifying, dispersing, wetting, permeability and buffering ability to PH value. One of the key points in the development of chemical products. Sodium metasilicate is a low-molecular-weight crystal obtained by the thermal reaction of ordinary foaming alkali and caustic soda water. The commodities include anhydrous, pentahydrate and nonahydrate, of which nonahydrate is only available in my country. It is an emergency product with low technical content that was developed in a hurry in the 1980s because of the urgent need for sodium metasilicate. Its melting point is only 42 °C, and when it is 30~40 °C, it will release crystal water, which brings great benefits to use. Inconvenient, it is easy to become liquid or paste during storage, and it is being phased out gradually. However, due to the habits of some users and the fact that some fields are not very concerned about crystal water, there is still a certain market for sodium metasilicate nonahydrate.

Among inorganic electrolytes, sodium metasilicate has the highest active alkalinity and PH buffer index, has strong wetting, emulsifying and saponifying grease, has excellent performance in removing, dispersing and suspending dirt, and can prevent dirt It can neutralize acidic dirt, emulsify fat and oil, has deflocculation effect on inorganic substances, and has anti-corrosion effect on metals. It can be used instead of sodium tripolyphosphate. Synthesize high-efficiency detergents and metal cleaning agents to reduce environmental pollution caused by sodium tripolyphosphate. The application of sodium metasilicate in detergent Chemicalbook has a history of more than 40 years abroad, and the application technology is relatively mature; it has been used in detergents and other industries for more than 20 years in China, and it is a mature chemical product. , but also has a mature and broad market. Sodium metasilicate is widely used in detergents, ceramics, electroplating, textiles, printing and dyeing, papermaking, cement, concrete, refractory materials, grease and leather processing and other industrial fields. At present, the industries with a large amount of application are: ceramics, industrial cleaning, detergents, concrete, printing and dyeing, papermaking, cement, oil extraction, and others.

White square crystals. Soluble in water and dilute lye, insoluble in alcohol and acid. The aqueous solution is alkaline.

Sodium metasilicate is widely used in various washing industries. In the washing industry, such as ultra-concentrated laundry powder, laundry liquid, laundry cream, dry cleaning agent, fiber bleach, fabric bleach, etc., it is also widely used in metal surface cleaning agents, beer bottles, floating product solvent cleaning agents, and full-dissolving agents. Afterwards, it can be used as metal rust inhibitor, scale cleaning agent, electrical device cleaning agent, and can be used as detergent in the food industry; it can also be used as mud consistency regulator and mud decoagulant in crude oil and natural drilling control and mining projects; in the construction industry It is used as a coagulant in the preparation of acid-resistant mortar, acid-resistant commercial concrete and cement; in the paper industry, it can be used as a binder, chemicalbook ink agent, and paper surface treatment agent; in the textile industry as a printing and dyeing auxiliaries, fabrics Pre-treatment agent; can also be used as a filler for soap, a preservative for detergents, eggs, as well as molecular sieves for vegetation, silicic acid and fireproofing materials. Sodium metasilicate has lubricity and can be used for the production of ceramic green mud; it has strong alkalinity, strong decontamination ability, large buffer capacity, and can neutralize acidic dirt. Emulsifies fat and oil, has deflocculation effect on inorganic substances, and has anti-corrosion effect on metals, so it is one of the main components in ultra-concentrated laundry detergents, and is also used in dishwashing detergents, food industry detergents, and metal detergents. And waste paper deinking, etc.

●  Mix sodium carbonate (or sodium hydroxide) and silica sand in a molar ratio of Na2O/SiO2=1:3, melt in a platinum crucible, and dissolve it in water to obtain an aqueous solution of sodium silicate. A calculated amount of sodium hydroxide was added to the solution, and Chemicalbook made the molar ratio of Na2O/SiO2 in the solution 1:1. The prepared solution composed of Na2O/SiO2 is heated to several tens of degrees, concentrated, cooled to 30°C to obtain nonahydrate, and heated to obtain anhydrous.

●   Dry method includes soda ash method, sodium sulfate (glauber's salt) method and trona method. Soda ash method: Mix soda ash and silica sand evenly in a certain proportion, and carry out melting reaction at 1400-150 Chemicalbook0 ℃. The molten material is quenched and cooled by water to form glass frit, which is put into the dissolving tank while hot, and then heated by steam. After sedimentation and concentration , making water glass.Sodium sulfate method: firstly mix sodium sulfate (glauber's salt) and pulverized coal uniformly, then add silica sand, and after mixing uniformly, quickly add it to the furnace for reaction. water glass.Trona method: mix trona, silica sand and pulverized coal in a certain proportion, then add caustic soda slag for adjustment, preheat the mixture on the top of the furnace for 2 to 4 hours, and then put Chemicalbook into the furnace for reaction, and generate after 3 to 5 hours. The molten material is quenched and cooled by the discharge water, and the glass frit formed by cooling is dissolved, precipitated and concentrated to obtain water glass.

●  The liquid caustic soda and silica sand are mixed into the autoclave in the appropriate proportion by wet method, and heated by direct steam. After the pressure in the reaction kettle rises to 0.7～0.Chemicalbook 8MPa, the direct steam is stopped, and the jacket steam is used for heat preservation. , maintain this pressure, react for several hours, filter and concentrate the reactant to obtain water glass.

●  Add the sodium hydroxide solution to the silica sand according to the theoretical amount, heat and stir until dissolved, and keep the reaction for several hours:After the reaction was completed, it was filtered. After the filtrate is concentrated, crystallize by cooling at about 30°C, and the separated crystals are washed with ethanol and dried.

●  Add 13% to 14% sodium hydroxide solution to water glass containing 30.8% of silicon dioxide and 14.34% of sodium oxide, and filter after stirring to make the filtrate completely transparent. Then, add a small amount of nonahydrate to the filtrate. Seed crystals of sodium silicate, let stand. After the crystals are suction filtered, washed with ethanol and dried.

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