What is the main use of anhydrous sodium carbonate_Industrial additives

What is the main use of anhydrous sodium carbonate [Background and Overview]

The chemical formula of sodium carbonate is Na₂CO₃, also called soda ash, commonly known as soda. Anhydrous sodium carbonate is white powder or fine particles, which melts without decomposing when heated to 851°C. The relative density is 2.532. Easily soluble in water, it releases heat when dissolved; because it is a strong base and weak acid salt, it is highly hydrolyzed in water, and its aqueous solution is strongly alkaline. Sodium carbonate often exists in the form of hydrates, and there can be several hydrates: monohydrate Na₂CO₃·H₂O, seven The water substance Na₂CO₃·7H₂O and the decahydrate substance Na₂CO₃·10H₂O. Daily edible alkali is mainly sodium carbonate decahydrate, commonly known as washing soda or crystal soda. It exists in saline-alkali lakes in mainland my country. When the weather is cold and low, large crystals precipitate on the lake surface, called trona. Transparent crystalline sodium carbonate decahydrate easily loses crystal water and turns into powder in dry air, mainly converting into sodium carbonate monohydrate. When sodium carbonate aqueous solution interacts with highly hydrolyzable metal ions, the hydrolysis promotes each other, and the final result is the precipitation of alkali carbonates or hydroxides. It is highly hygroscopic and can form hard lumps after absorbing moisture. It can gradually absorb carbon dioxide from the humid air and become sodium bicarbonate. Sodium carbonate is one of the important products in the chemical industry and has a wide range of uses. It is an important raw material for glass, papermaking, soap, detergent, textile, tanning, petroleum, dyes, food and other industries.

It is used as a flux in the metallurgical industry, as a softener in water purification, as a degreaser on the surface of mechanical parts, and in the preparation of sodium and other compounds. As a benchmark reagent, anhydrous sodium carbonate is widely used in chemical analysis in various industries. The current method of preparing anhydrous sodium carbonate is to dissolve industrial anhydrous sodium carbonate in hot distilled water, then filter and concentrate the aqueous solution to obtain the used reference reagent anhydrous sodium carbonate. This method can only remove water-insoluble impurities in industrial anhydrous sodium carbonate, but cannot remove Mg²⁺ and Ca²⁺ contained in industrial anhydrous sodium carbonate. sup> and Fe²⁺, which will affect the detection accuracy obtained during chemical analysis, which may lead to errors in the test results; at the same time, the sodium carbonate solution should be concentrated for a long time to make it anhydrous. The clarity of the finished sodium carbonate product is not high, resulting in a low product qualification rate.

What is the main use of anhydrous sodium carbonate [Application]

Sodium carbonate is an important basic chemical raw material. Its main uses are: ①Producing various glasses. It is used as a glass regulator or flux in the glass raw material to break the Si-O bonds in the quartz sand (glass forming body) to make it fusible, reduce the viscosity, and increase the expansion coefficient. ②Chemical raw materials. For example, it reacts with quartz sand to produce sodium silicate (water glass), which is used to prepare various insoluble carbonates, used to prepare bleaches, detergents, catalysts, dyes, and as ore processing reagents. ③ In the metallurgical industry It is used to remove sulfur and phosphorus and is used as a flux. In addition, it is also used in papermaking, soap making, refractory materials and glazes, water purification, and as an alkaline flux in the laboratory. Soda ash can replace hydrogen in production. Sodium oxide to neutralize acid:

Sodium carbonate can form crystalline hydrates containing different numbers of water molecules. Sodium carbonate decahydrate is also called crystal soda or washing soda. It absorbs heat when dissolved in water. It is easily weathered in the air and loses crystal water. Mainly used as washing soda, suitable for washing textiles, and used as bleaching agent for cotton and linen. Sodium carbonate monohydrate, the most stable form of sodium carbonate, is used in the photographic industry as a developer component.

What is the main use of anhydrous sodium carbonate [Preparation]

Method 1: A method for preparing anhydrous sodium carbonate, characterized in that: the steps of the preparation method include:

1) Dissolve industrial sodium carbonate in water to make an industrial sodium carbonate aqueous solution. Use sodium hydroxide to adjust the Ph value of the industrial sodium carbonate aqueous solution to 13-14, stir and heat to 55-65°C, and react for 0.5-1.5 hours. After incubation for 1.5 to 2.5 hours, filter to remove Mg²⁺ and Ca²⁺ sodium carbonate aqueous solution;

2) Add hydrogen peroxide to the aqueous sodium carbonate solution to remove Mg²⁺ and Ca²+. After incubation for 22 to 24 hours, filter to remove Fe^{2 +}Sodium carbonate aqueous solution;

3) Pour CO₂ into the Fe²⁺ sodium carbonate aqueous solution to reach saturation, and obtain a sodium bicarbonate aqueous solution with sodium bicarbonate precipitated;

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4) Suction filter the sodium bicarbonate aqueous solution to obtain sodium bicarbonate crystals;

5) Wash the sodium bicarbonate crystals with water, dehydrate them, and dry the dehydrated sodium bicarbonate crystals to obtain the finished product of the reference reagent anhydrous sodium carbonate. Methoxyphenylboric acid

Method 2: A method for preparing high-purity anhydrous sodium carbonate, which is characterized by: the method is as follows:

1) Dissolve anhydrous sodium carbonate:

Slowly add industrial pure anhydrous sodium carbonate into a stainless steel bucket of distilled water, stir continuously and measure its relative density to be 1.16~1.18g/polycarbonate mL to obtain solution A;

2) Preparation of crystalline sodium carbonate:

Put analytically pure ethanol into a stainless steel basin, place activated carbon and a low-purity filter sieve on the basin, then slowly pour solution A into the sieve and filter, the filtrate flows into the ethanol basin, stir continuously, and cool naturally until sodium carbonate Precipitate, filter and dry to obtain sodium carbonate B;

3) Prepared�Pure anhydrous sodium carbonate:

Put the B obtained in step (2) into a polyethylene plastic bucket, add distilled water, stir and dissolve, filter the solution with a Buchner funnel, put the filtrate into a platinum evaporating dish, heat to evaporate, heat and stir at 180°C ~ 200 ℃, until crystallization occurs, spin it dry with a stainless steel centrifuge while it is hot, place the crystals in a platinum evaporation dish, heat it on a muffle furnace, turn it continuously until it loses moisture, move it to a vacuum dryer, cool and dry, and obtain high purity Anhydrous sodium carbonate.

What is the main use of anhydrous sodium carbonate [Main reference materials]

[1] Zhang Weiling. Preparation method of anhydrous sodium carbonate. CN200810151994.1, application date 2008-10-06

[2] Hu Jianhua. A method for preparing high-purity anhydrous sodium carbonate. CN201010229244.9, application date 2010-07-17

[3] Encyclopedia of Chinese Middle School Teaching·Chemistry Volume

[4] Social Dictionary of Science and Technology·Chemistry