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Send EmailSodium Carbonate, soda ash, Sodium carbonate anhydrous, 497-19-8 , 7542-12-3
CAS: 497-19-8; 7542-12-3
Molecular Formula: CH2O3.2Na
Names and Identifiers
| Name | Sodium carbonate |
| Synonyms | ASH ODA ASH soda ash Soda (VAN) calcined soda SODA ASH LIGHT Sodium carbonate disodium carbonate Sodium carbonate,dense Sodium carbonate solution Carbonic acid, sodium salt Sodium carbonate anhydrous Anhydrous Sodium carbonate carbonic acid, sodium salt ANHYDROUS SODIUM CARBONATE Carbonic acid disodium salt SODA ASH (LIGHT AND DENSE ) Sodium carbonate,high-purity Sodium carbonate-12C, 13C-depleted |
| CAS | 497-19-8 7542-12-3 |
| EINECS | 231-867-5 |
| InChI | InChI=1/CH2O3.2Na/c2-1(3)4;;/h(H2,2,3,4);;/q;2*+1/p-2 |
| InChIKey | CDBYLPFSWZWCQE-UHFFFAOYSA-L |
Physico-chemical Properties
| Molecular Formula | CH2O3.2Na |
| Molar Mass | 105.99 |
| Density | 2.53 |
| Melting Point | 851 °C (lit.) |
| Boling Point | 1600°C |
| Water Solubility | 22 g/100 mL (20 ºC) |
| Solubility | H2O: 1M at20°C, clear, colorless |
| Appearance | White powder or granule |
| Specific Gravity | 2.532 |
| Color | White |
| Maximum wavelength(λmax) | ['λ: 260 nm Amax: 0.01', , 'λ: 280 nm Amax: 0.01'] |
| Merck | 14,8596 |
| BRN | 4154566 |
| pKa | (1) 6.37, (2) 10.25 (carbonic (at 25℃) |
| PH | 10.52(1 mM solution);10.97(10 mM solution);11.26(100 mM solution); |
| Storage Condition | 15-25°C |
| Stability | Stable. Incompatible with powdered alkaline earth metals, aluminium, organic nitro compounds, fluorine, alkali metals, nonmetallic oxides, concentrated sulfuric acid, oxides of phosphorus. |
| Sensitive | Hygroscopic |
| Refractive Index | 1.535 |
| MDL | MFCD00003494 |
| Physical and Chemical Properties |
properties a pure product of anhydrous sodium carbonate is a white powder or fine particles. |
| Use | Basic chemical raw materials, widely used in medicine, paper, metallurgy, glass, textile, dye and other industries, used as food industry fermentation agent |
497-19-8 - Risk and Safety
| Risk Codes | R32 - Contact with acids liberates very toxic gas R36 - Irritating to the eyes R51/53 - Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment. R36/37/38 - Irritating to eyes, respiratory system and skin. R41 - Risk of serious damage to eyes R37/38 - Irritating to respiratory system and skin. |
| Safety Description | S36/37 - Wear suitable protective clothing and gloves. S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S22 - Do not breathe dust. S36 - Wear suitable protective clothing. S39 - Wear eye / face protection. |
| WGK Germany | 2 |
| RTECS | XN6476000 |
| FLUKA BRAND F CODES | 3 |
| TSCA | Yes |
| HS Code | 28362000 |
| Toxicity | LD50 orally in Rabbit: 4090 mg/kg |
497-19-8 - Upstream Downstream Industry
Nature
white powder. Melting point 851 deg C; d 2. 53. Sodium carbonate is very susceptible to hygroscopic deliquescence in air. Carbon dioxide begins to decompose at 400 °c. Room temperature can be dissolved in 3.5 parts of water, 2.2 parts of 35 ° C water, soluble in glycerol, insoluble in ethanol. Its aqueous solution is strongly alkaline, ph 11.6.
Preparation Method
The sodium carbonate decahydrate was placed in a silver dish in an autoclave, and the sodium bicarbonate was obtained by saturated Suction filtration with carbon dioxide. After washing with ice water, the sodium carbonate was heated and decomposed to constant weight, and pure anhydrous sodium carbonate was obtained.
Standard
This product is obtained by ammonia alkali method also known as Solvay method. The content of Na2C03F should be less than 99.0% based on the dry product.
Trait
Authoritative Data Verified Data
- This product is white or off-white crystalline powder with hygroscopicity.
- This product is soluble in water and almost insoluble in ethanol.
Introduction
No smell. It has an alkali taste. It's hygroscopic. The exposed air gradually absorbs 1mol/L water (about 15%). Carbon dioxide is lost at 400 ℃. Decompose and effervescent in case of acid. Soluble in water (3.5 parts at room temperature and 2.2 parts at 35 ℃) and glycerol, insoluble in alcohol. The aqueous solution is strongly alkaline, pH11.6. Median lethal dose (30 days) (mice, abdominal cavity) 116.6 mg/kg. It's irritating.
Use
In the quantitative analysis, aluminum, sulfur, copper, lead and zinc were determined as the reference substance of acid solution. Examination of urine and whole blood glucose, analysis of silica in cement flux, metal metallographic analysis.
Differential diagnosis
This product is the identification of sodium salt and carbonate reaction (General 0301).
Safety
It was packed with a plastic woven bag of inner village polyethylene plastic bag, each with a net weight of 40kg. Should be stored in a cool, dry warehouse, transport is strictly prohibited hook, to prevent bag break package, not with the acid, ammonium salt storage and mixed transport. To avoid moisture, heat, transport should be protected from rain and sun exposure.
Exam
clarity and color of solution
take 2.0g of this product, Add 10ml of water to dissolve, and check according to law (General rule 0901 and general rule 0902), the solution should be clear and colorless; If it is turbid, with No. 1 turbidity standard solution (General rule 0902) comparison, not more concentrated; If the color, with the yellow No. 1 Standard Colorimetric liquid (General Principles 0901 The first method), not deeper.
chloride
take this product 0 .4G, inspection according to law (General rule 0801), and standard gasification sodium solution 5 .0 m l made of the control liquid comparison, not more concentrated (0.0125%),
sulfate
take this product l.O g, checked according to law (General rule 0802), with standard potassium sulfate solution 2. Compared with the control solution made of 5 m l, it should not be more concentrated (0. 025%)o
ammonium salt
take l.O g of this product, add 10ml of sodium hydroxide test solution, heat, the steam occurs in the wet red litmus test paper shall not turn blue. Argon sodium carbonate take 0 .4g of this product, add 20ml of water to dissolve, add 20ml of gasified barium test solution, and filter. 10M l of continued filtrate was added with 0 .1M l of human phenolphthalein indicator solution, and the solution should not turn red; The remaining continued filtrate was boiled for 2 minutes, and the solution should still be clear.
loss on drying
take this product and dry it at 105 * C for 4 hours, and the weight loss shall not be over 0831 (general rule).
Iron Salt
take this product l.O g, add appropriate amount of water to dissolve, add dilute hydrochloric acid to make it slightly acidic, boil to remove carbon dioxide gas, cool, dilute with water to make 2 5 m l, and check according to law (General rule 0807), with standard iron solution 5. Compared with the control solution made of 0M l, it should not be deeper (0.005%).
Heavy metals
The test sample solution under the arsenic salt inspection item shall be inspected according to law (General rule 0821, Law 1), and shall comply with the regulations (50 parts per million).
arsenic salt
take 2.0g of this product, add 5M l hydrochloric acid and 25ml water, boil to remove carbon dioxide gas, cool, 5m o l/L sodium hydroxide solution was added dropwise until the solution was neutral and diluted with water to 50 m l. After shaking, 10ml was collected and checked according to law (General rule OS22 method 1), the provisions (0.0005%) shall be met.
Content determination
take about 1.5g of this product, precision weighing, add water 50tnl to dissolve, add 10 drops of Methyl red-bromocresol green mixed indicator solution, and use hydrochloric acid titration solution (1.0 mol/L) titration until the solution changed from green to purple, boiled for 2 minutes, cooled to room temperature, continued titration until the solution changed from green to dark purple, and the titration results were corrected with a blank test. Each lm l of hydrochloric acid titration solution (1.0 mol/L) corresponds to 53.0 mg of Na2C03.
Category
pharmaceutical excipients, p H value regulator, etc.
Storage
sealed storage.
Reference Information
| overview | the chemical formula of sodium carbonate is Na2CO3, commonly known as soda ash, soda, alkali ash and washing alkali. under normal circumstances, it is white powder and is a strong electrolyte. The density is 2.532g/cm3, the melting point is 851°C, it is easily soluble in water and has the generality of salt. It is a weak acid salt, slightly soluble in absolute ethanol, insoluble in propanol, and hydrolysis occurs after dissolving in water The reaction makes the solution alkaline and has a certain degree of corrosiveness. It can neutralize with acid to generate corresponding salts and release carbon dioxide. It can be decomposed at high temperature to produce sodium oxide and carbon dioxide. Long-term exposure to the air can absorb moisture and carbon dioxide in the air, generate sodium bicarbonate, and form hard lumps. The hygroscopicity is very strong, it is easy to form hard lumps, and it does not decompose at high temperatures. Sodium carbonate and water generate Na2CO3 · 10H2O,Na2CO3 · 7H2O,Na2CO3 · H2O, of which Na2CO3 · 10H2O is the most stable, and the heat of dissolution in water is very small. It is mostly used in the photographic industry, and its trade name is carbon oxygen. Na2CO3 · 10H2O is also called crystalline alkali, which is easy to weather in dry air. In the past, crystalline alkali was often used for household washing and washing of wool, so it is also called "washing alkali". In the past, Chinese folk used to use "block alkali" that can wash clothes and produce noodles, which was made by stirring soda ash with an increased amount of water (plus some baking soda (NaHCO3), its water content is above 50%. Sodium carbonate is endothermic when dissolved in water, and it is easy to weather in the air. Na2CO3 · 7H2O is unstable and can only be precipitated from sodium carbonate saturated solution in the range of 32.5~36 ℃. Sodium carbonate is a weak acid and strong alkali salt (soda ash is salt, not alkali, but the solution is strongly alkaline). Na2CO3 produced by chemical methods is purer than trona, so people call it "soda ash". |
| solubility in water | maximum dissolved grams per 100g of water at different temperatures (℃): 7.0g/0 ℃;12.2g/10 ℃;21.8g/20 ℃;29.4g/25 ℃;39.7g/30 ℃;48.8g/40 ℃;47.3g/50 ℃;46.4g/60 ℃;46.2g/70 ℃;45.8g/80 ℃;45.7g/90 ℃;45.5g/100 ℃; |
| and identification of sodium bicarbonate | the two substances are heated in two test tubes, and the other end of the test tube is filled with clear lime water. if it is observed that the clear lime water becomes turbid, then the substance in this test tube is sodium bicarbonate, while the substance in the test tube where the clear lime water becomes turbid is sodium carbonate. Principle: 2NaHCO3 = Na2CO3 H2O CO2 ↑ (condition is heating),Na2CO3 heating does not decompose. |
| toxicity | ADI (daily allowable intake) is not restricted (FAO/WHO1985 year). LD50 (median lethal dose) is about 6 g/kg (oral in mice). Soda ash dust has irritating effect on skin, respiratory tract and eyes. Long-term contact with soda ash solution may cause eczema, dermatitis, etc. Its concentrated solution can cause burns, necrosis, and even corneal turbidity. The maximum allowable concentration of soda ash dust in the air is 2mg/m3. Operators should wear work clothes, door covers, gloves, boots and other labor protection supplies to protect respirators and skin. |
| use | in production and life, sodium carbonate is used to make pastry, sodium hydroxide, etc., or as a formula for various detergents. It is used as a softener for water purification. In industrial soda ash, it is mainly light industry, building materials, and chemical industries, accounting for about 2/3; followed by metallurgy, textiles, petroleum, national defense, medicine and other industries. The glass industry is the largest consumer of soda ash, consuming 0.2 tons of soda ash per ton of glass. The chemical industry is used in the production of water glass, sodium dichromate, sodium nitrate, sodium fluoride, baking soda, borax, trisodium phosphate, etc. Metallurgical industry is used as smelting flux, flotation agent for beneficiation, steelmaking and antimony smelting as desulfurizer. The printing and dyeing industry is used as a water softener. The leather industry is used for degreasing, neutralizing chrome tanning and improving the alkalinity of chrome tanning liquid. It is also used to produce synthetic detergent additives sodium tripolyphosphate and other sodium phosphate salts. Edible soda ash is used to produce monosodium glutamate, pasta, etc. One of the basic chemical raw materials, it has a wide range of uses. It is an important raw material for glass, soap, detergent, textile, tanning, spices, dyes, medicines, etc. Used as an analytical reagent, also used in pharmaceutical industry and photographic plate making widely used in glass products, chemicals, papermaking, metallurgy, medicine, textile and food industries color TV special reagent used in food industry, as neutralizer, leavening agent, such as manufacturing amino acids, soy sauce and flour food such as steamed bread, bread, etc. It can also be mixed into alkaline water and added to pasta to increase elasticity and ductility. As a detergent for wool rinsing, bath salt and medicine, alkali in tanning. Most of them are used in industry, and a small part is for civilian use. In industrial soda ash, it is mainly light industry, building materials, and chemical industries, accounting for about 2/3: followed by metallurgy, textiles, petroleum, national defense, medicine and other industries. The glass industry is a large consumer sector of soda ash, consuming soda ash O.2t per ton of glass. The chemical industry is used in the production of water glass, sodium dichromate, sodium nitrate, sodium fluoride, baking soda, borax, trisodium phosphate, etc. Metallurgical industry is used as smelting flux, flotation agent for beneficiation, steelmaking and antimony smelting as desulfurizer. The printing and dyeing industry is used as a water softener. The leather industry is used for degreasing, neutralizing chrome tanning and improving the alkalinity of chrome tanning liquid. It is also used to produce synthetic detergent additives sodium tripolyphosphate and other sodium phosphate salts. As a buffer, neutralizer and dough improver, it can be used for pastries and noodles, and it can be used in an appropriate amount according to production needs. Mainly used for float glass, picture tube glass shell, optical glass, etc. It can also be used in other sectors such as chemical industry and metallurgy. The use of heavy soda ash can reduce the soaring of alkali dust, reduce the consumption of raw materials, improve working conditions, improve product quality, reduce the erosion of alkali powder on refractory materials, and extend the service life of the kiln. Basic chemical raw materials are widely used in medicine, papermaking, metallurgy, glass, textile, dye and other industries. Basic chemical raw materials, widely used in medicine, papermaking, metallurgy, glass, textile, dye and other industries, used as food industry starter used as analytical reagents, dehydrating agents, battery additives, etc. |
| Industrial preparation method | Made from ammonia, carbon dioxide and saturated salt water as raw materials, it is called the combined alkali method, which is improved by Chinese chemist Hou Debang on the basis of ammonia alkali method. The method won a gold medal at the World Expo. In North America, due to the existence of a large number of natural sodium carbonate deposits, artificial processing and refining with natural alkali is the main means to produce sodium carbonate. Sodium carbonate is an important raw material in chemistry and industry. In 2003, China's sodium carbonate production surpassed that of the United States and ranked first in the world. Before the invention of the combined alkali method, the ammonia-alkali method (also known as the Solvay alkali method) was the most widely used. It was invented by Belgian Ernest Solvay in 1862. The reaction is carried out in three steps: 1.NH3 CO2 H2O → NH4HCO32.NH4HCO3 NaCl → NaHCO3 NH4Cl3.2NaHCO3 → Na2CO3 CO2 H2O The CO2 generated by the reaction can be recycled and reused, and NH4Cl can react with quicklime to produce NH3, which can be used again as raw materials: 2NH4Cl CaO → 2NH3 CaCl2 H2O ammonia-alkali method enables continuous production, improved salt utilization rate, and pure product quality, so it is called "soda ash", but the biggest advantage is the low cost. In 1867, the products manufactured by Solvay's factory won a bronze medal at the Paris World Exposition. This method was officially named Solvay. At this time, the price of soda ash dropped greatly. The news reached the United Kingdom, and the British Hutchinson Company, which is engaged in the law of Lubran, obtained the right to monopolize Solvay for two years. In 1873, the Hutchison Company was reorganized into the Bu Neimen Company and established a large-scale production plant for soda ash. Later, France, Germany, and the United States successively established factories. These countries initiated the organization of the Solvay Guild, and the design drawings were only disclosed to member states, and they were absolutely kept secret. Where there are improvements or new discoveries, member states ventilate each other and meet not to apply for patents to prevent leakage. In addition to technology, there are also restrictions on business. They adopt the method of regional sales. For example, the Chinese market is monopolized by the British Bu Neimen Company. Because of such a tight organization, anyone who cannot be franchised by the Solvay Association has no way to ask for details of ammonia-alkali production. Until the beginning of the 20th century, many countries who wanted to explore the mysteries of Solvay, all failed. It was not until the end of the relevant patent that this production method came to light. The difference between Hou's and Soxhlet's methods: the main reaction is the attitude towards ammonium chloride. Soxhlet is added with quicklime to make ammonia escape, while Hou is added with salt to crystallize ammonium chloride. |
| Production method | At present, the methods for producing heavy soda ash from light soda ash in industry include solid-phase water method, liquid-phase hydration method and extrusion method. There are evaporation method and carbonation method using trona as raw material. The latter two methods have been mentioned in the industrial sodium carbonate part, so only three methods using pure alkali as raw material are described. The solid-phase water method hydrates high-temperature light soda ash with 50~70 ℃ hot water at 90~97 ℃ to generate sodium carbonate monohydrate, calcines at 130~150 ℃, and then sieves to produce heavy soda ash finished products. Its Na2CO3 + H2O → Na2CO3 · H2ONa2CO3 · H2O[△] → Na2CO3 + H2O liquid phase water method high temperature light soda ash is dissolved with water and circulating mother liquor at about 100 ℃, saturated solution is prepared and hydrated, then pumped to crystallizer. The temperature is cooled to 80~90 ℃ to form a suspension of sodium carbonate monohydrate, which is thick and separated to produce a finished heavy soda ash. The reaction formula is the same as the solid phase water method. The high-temperature soda ash (150~160 ℃) from the alkali bin is extruded into hard flakes with a thickness of about 2 mm under a pressure of 5000~7000kg/cm2 by extrusion method, and then crushed and sieved to obtain heavy soda ash products with suitable particle size. Large grains return to break. The small grains are re-squeezed and recycled separately. 1. The ammonia-alkali raw salt (salt) is dissolved in water, and an appropriate amount of lime milk is added to remove magnesium, and CO2 is introduced to remove calcium. The purified salt water is introduced into ammonia gas for ammonia absorption, and CO2 is introduced into the ammonia absorption mother liquor for carbonization, sodium bicarbonate is precipitated, and sodium carbonate is obtained by filtration and calcination. Add lime milk to the mother liquor and evaporate ammonia for ammonia absorption. NaCl + NH3 + CO2 + H2O → NaHCO3 + NH4Cl2NaHCO3 → Na2CO3 + CO2 + H2O ↑ 2 combined alkali method will ammonia gas through the mother liquor of human salting-out crystallization for ammonia absorption, ammonia absorption mother liquor and carbon through human CO2 for carbonization, sodium bicarbonate crystallization is precipitated, and soda ash is obtained by filtration and calcination. The mother liquor absorbs ammonia and precipitates ammonium chloride crystals. After filtration, salt is added to further precipitate ammonium chloride crystals. After filtration, the mother liquor re-sucks ammonia and circulates continuously. The reaction formula is the same as the ammonia-alkali method. There are ammonia-alkali method, combined alkali method, trona processing, etc. The main reactions of ammonia-alkali method are as follows: NaCl + NH3 + CO2 + H2O → NaHCO3 + NH4Cl2NaHCO3 → Na2CO3 + CO2 + H2O. The process flow is briefly described as follows: the raw salt is dissolved in water, and refined salt water (or secondary salt water, the same below) is made after calcium and magnesium are removed. The secondary brine absorbs ammonia to prepare ammonia brine with NaCl concentration above 89 titer and FNH3 to Na + concentration ratio of 1.13~1.18. The oxygen brine is cooled to 35~38 ℃ and then sent to the carbonization section, and reacts with the compressed carbon dioxide from the lime kiln and calciner to form a sodium bicarbonate suspension, which flows to the filtration section, and the sodium oxycarbonate (heavy Alkali) crystals are separated from the suspension, sent to the upper calcination section, calcined and decomposed at about 160 ℃ to produce soda ash products. The filtered mother liquor is mixed with the lime milk from the lime section to make a blending liquid, and the ammonia in it is heated by steam in a distillation tower for the salt water to absorb ammonia and recycle. The production process of the combined alkali production method is divided into the alkali production process (also known as the I process) and the ammonium production process (also known as the II process), the co-production of soda ash and ammonium chloride, and the mother liquor constitutes a closed cycle in the two processes. The main reaction is the same as the ammonia-alkali method. The process flow is briefly described as follows: the raw salt (sodium chloride) is washed with saturated brine to remove calcium and magnesium impurities, and then crushed, washed, thick and separated to obtain washing salt with specified purity (containing NaCl ≥ 98%) and particle size (10~20 mesh) and sent to salting-out crystallizer. The mother liquor II overflowed from the salting-out crystallizer absorbs ammonia in the ammonia absorber to make ammonia mother liquor II, and after clarification, it is sent to the carbonization tower to absorb carbon dioxide (carbonization) to make a sodium bicarbonate suspension. The sodium bicarbonate suspension is filtered to obtain solid sodium bicarbonate, and then calcined to obtain soda ash products. The mother liquor (mother liquor I) after filtering the heavy alkali is made into ammonia mother liquor I through ammonia absorption, heat exchange with the mother liquor II through a heat exchanger, and send it to a cold precipitation crystallizer after cooling, and pass through an external cooler and A cold body (brine) or a refrigerant (liquid ammonia) directly exchanges heat, and some ammonium chloride is precipitated by cooling at 5~10 ℃. Cold precipitation crystallizer overflow (half mother liquor II) flow into the salt-out crystallizer, add washing salt and then precipitate part of ammonium chloride. The ammonium chloride suspension taken out from the cold and salting crystallizer is thick and separated to obtain wet ammonium chloride, which is sent to a dry ammonium furnace for drying and is an ammonium chloride product. Salting-out crystallizer overflow liquid (mother liquor II) and ammonia mother liquor L heat exchange after ammonia absorption ammonia mother liquor II, and then sent to the carbonization tower to make alkali. In such a continuous cycle, two products, soda ash and ammonium chloride, are continuously produced. Trona processing method double half alkali process This method is a method of producing soda ash with double half alkali as raw material. Some trona processing plants in the United States use. The ore is crushed to about 20 mesh (O.8mm), sent to the dissolution tank, dissolved with circulating mother liquor to make a saturated solution, entered the clarification barrel for clarification, and the bottom flow is sent to the thickener, and water is added to wash and recover the alkali in the mud. The overflow liquid of the clarification barrel is filtered and sent to a three-effect evaporator for evaporation, and the crystal slurry taken out of the third-effect evaporator is pumped into a thickener, and then centrifugally dehydrated to obtain a sodium hemicarbonate filter cake, soda ash is prepared by calcination. Carbon monohydrate process This method is also a method of producing soda ash with half alkali as raw material. Its product quality is better than half alkali process, which is adopted by most trona processing plants in the United States. The ore is crushed to about 6mm, sent to a calciner, calcined at about 150 ℃, most of the ore is coarse soda ash, entered into a dissolution tank, dissolved under the condition of slightly lower than 100 ℃, clarified and sent to a three-effect evaporator, The concentrated suspended lye is separated to obtain sodium carbonate monohydrate, and sent to a dryer to dry to obtain heavy soda ash. Carbonation method This method is the production method of trona halide as raw material, and the processing of trona in China's Dabusu and other places is used. The alkali halogen dissolved in trona or dissolved in water is clarified and preheated by carbon dioxide for carbonation, and then filtered and calcined to obtain soda ash products. In the mid-1980s, the ammonia carbonization method was successfully developed. The refined alkali halogen first absorbs nitrogen and then carbonizes, and then the process is the same as before. Compared with the direct carbonization method, the utilization rate of sodium can be increased from 25% to 65% ~ 70%. The natural alkali halogen evaporation method uses the dissolved natural alkali ore or the natural alkali excavated from the alkali lake to obtain the alkali halogen, which is refined, separated, preheated, evaporated, separated, and calcined to obtain the warbler soda ash. sodium carbonate synthesis method dissolves crude sodium carbonate and sodium bicarbonate through steam, settles and removes impurities, clears the liquid, reacts with carbon dioxide to a certain concentration, and then distilled, cooled, and crystallized to obtain sodium hemicarbonate. its Na2CO3 + NaHCO3 + 2H2O → Na2CO3 · NaHCO3 · 2H2O trona method uses trona as raw material to dissolve through steam to clarify impurities, and the clear liquid contains sodium carbonate, sodium bicarbonate, sodium sulfate and other components, part of Na2CO3 is carbonated into NaHCO3 by kiln gas carbonization, and the corresponding compound is formed by evaporation at 60 ℃, and the finished product of sodium sesquicarbonate is separated. The mother liquor can be precipitated by evaporation. Its 3Na2CO3 + 5H2O + CO2 → 2(Na2CO3 · NaHC03 · 2H2O) At present, edible soda ash is directly manufactured by ammonia-alkali method or combined alkali method in China. In the production of light soda ash, the refining process of removing arsenic and removing heavy metal impurities should be added. For other procedures, see Industrial Sodium Carbonate. |
| category | toxic substances |
| toxicity classification | poisoning |
| acute toxicity | oral administration-rat LD50 4090 mg/kg; Oral administration-mouse LD50: 6600 mg/kg |
| stimulation data | skin-rabbit 500 mg/24 hours mild; Eye-rabbit 100 mg/24 hours moderate |
| explosive hazard characteristics | corrosive |
| flammability hazard characteristics | non-combustible; toxic sodium oxide smoke is produced at the fire site; |
| storage and transportation characteristics | warehouse low temperature, ventilation, drying |
| fire extinguishing agent | water, carbon dioxide, dry powder, sand |
