Soda Ash also known as sodium carbonate is one of the most important and widely used chemicals in industry and has many applications. The main use of soda ash is in the glass industry. This material turns into glass after cooling when heated to high temperatures and combined with sand.
Soda ash is produced on an industrial scale through the Solvay process using limestone (calcium carbonate), ammonia and salt (sodium chloride). One of its most important applications is the use of this material in the glass industry. The purity of it is usually reported based on the amount of sodium oxide (Na2O), so that each kilogram contains 0.585 kg of sodium oxide.
It is a white or colorless solid. It is also a relatively strong base and has many uses. It is available in both crystal and powder form.
The Egyptians first discovered the natural form of soda ash 5,000 years ago and used its natural form. Soda ash in the form of alkaline salts was extracted from the bottoms of dried up lakes in Egypt and used in the preparation of mummies, soaps, and for the initial manufacture of glass.
In 1791, a French chemist named Nicolas Lebans used coal to produce. He first boiled sodium chloride and converted it to sodium sulfate. Sodium sulfate was then heated with limestone and crushed coal to finally be converted. Until the late 1880s, this method was used to produce soda ash.
It is the most widely used chemical. The high use of this material and its high impact in various industrial fields, has caused it to find many fans and be used by countless industrialists.
One of the chemical reactions of soda ash is its reaction with carbonic acid (carbon dioxide and water), which leads to the production of sodium bicarbonate (sodium hydrogen carbonate).
Soda ash looks like a solid, white powder that has no odor and absorbs moisture, which is widely used in the detergent and disinfectant industry to protect against a variety of fungi and viruses.
It has been extracted in the past from plant ash grown in sodium rich soils. This is why it is so called soda ash. Today, it is is synthesized industrially from the reaction of hydrated lime (calcium carbonate) with sodium chloride salt during the Solvay process or the ammonia soda process. The enthalpy of aqueous solution of 10% by weight. As mentioned, it is one of the most important applications of soda ash in the glass industry. In this way, by heating this material at very high temperatures and then combining it with sand and then cooling it, glass is obtained.
There are generally two methods for producing which are:
1- Chemical synthesis
2- Extraction from natural sources
In 1861, a Belgian chemist named Ernest Solvay introduced a method for the synthesis of soda ash in which sodium chloride and limestone (calcium carbonate) were used as raw materials and ammonia was used as a catalyst.
In this method, first sodium chloride salt is dissolved in water to obtain a salt saturation solution, then the reaction is done by passing the salt saturation solution through two consecutive towers, in the first tower ammonia bubbles from the bottom of the tower upwards. Comes and is absorbed and dissolved by brine solution. In the second tower, by injecting carbon dioxide gas, the bubbles of this gas pass through a solution of ammonia salt water and sodium bicarbonate (sodium hydrogen carbonate or baking soda) is obtained.
The carbon dioxide required for this step is obtained from the thermal decomposition of limestone (calcium carbonate). By heating limestone, in addition to carbon dioxide, calcium oxide is also obtained, which will be used in ammonia recycling.
The product of this process is sodium bicarbonate and ammonium chloride solution, which is passed through a filter, its sodium bicarbonate is separated and transferred to the next stage of soda ash production.
Sodium bicarbonate from the first stage process is converted to soda ash by thermal method (calcination) and loss of water and carbon dioxide. It should be noted that the carbon dioxide obtained at this stage is returned to the first stage for reuse.
In the side part of this process, ammonium chloride is reacted with calcium oxide from the limestone thermal decomposition process (calcium carbonate), and the ammonia is reduced and returned to the first stage of the reaction. Also a byproduct of this process is calcium chloride, which can be sold.
(It should be noted that depending on the soil conditions of agriculture in different countries, instead of recycling ammonia, the product of ammonium chloride can be sold directly as a chemical fertilizer.)
The raw materials required for the production of soda ash by this method is: limestone (calcium carbonate), sodium chloride salt and ammonia
Limestone (CaCO3) used in the soda ash production process must be at least 84% pure. However, due to the quality of the mine, the purity of limestone is different, so its consumption in the process of producing soda ash is different. Consumption of it according to the quality of limestone (84% to 98%) is estimated at about 1090-1820 kg per ton of product produced.
The salt used in this process, depending on its quality, is about 1500-1830 kg per ton of product produced.
In this method, mineral compounds such as Terona and Nephline, which contain soda ash and sodium bicarbonate, are exploited. This method is used in countries such as the United States and Turkey, which have large reserves of Trona.
This type of stone is prepared and used in glass industry, chemical industry, water purification, soap production and paper making. Heavy soda ash is mostly used in solid form.
This type contains 0.5% sodium chloride and is used as a pH regulator in the chemical industry.
The main difference between heavy and light soda ash is in the density and type of use, otherwise they are not different. Particle size is also different in these two types.
Soda ash is used in many industries and has many applications. Here are some of the most important uses:
Glass industry: reduces energy consumption and lowers the temperature of glass formation.
Production of chemicals: Used in the production of chemicals such as sodium silicate, sodium aluminate and sodium triple phosphate and..
Paper making and paper production: regulates acidity and eliminates the color of waste paper.
Production of soap, toothpaste and detergents: raises the pH and acts as a foaming agent.
Removes water hardness: By removing calcium and magnesium in water, it eliminates water hardness.
Petrochemical industry: Used as a neutralizer.
Refining crude oil and petroleum products: Used as a neutralizer in petroleum processes.
Textile industry: Used as an antacid in silk processing.
Chemistry laboratories: It is used in titration reactions.
Food industry: regulates pH and is used as a preservative.
Brick-making and brick-making workshops: It is used in the production of dough as a moisturizer and reduces water consumption.
Dyeing: Strengthens the bond between dye and fibers.
Urban water reservoirs: neutralizes the acidic effect of chlorine and increases pH.
Home use: It acts as a water softener for washing clothes.
Refining vegetable oils: Separates free fatty acids.
Taxidermy: Used to remove meat from bones.
Desulfurization: Eliminates the sulfur in the smoke coming out of the chimneys.
Pools: Used to regulate the pH of water and eliminate the problems that pool water creates for the skin.
Soda ash has no negative impact on the environment. it affects the pH of the environment. If the concentration of this substance is less than 100 mg / l and is diluted, it does not affect the environment and does not change the pH.
Soda ash affects the body and in contact with the skin. Although these effects are minor and not very dangerous, it is best to be aware of these effects:
This chemical is not harmful if swallowed unless it is very large.
Inhaling it irritates the nose and throat.
If it comes in contact with the skin, it will cause itching and irritation of the skin.
When in contact with the eyes, it also causes irritation and redness in the eyes.
Fine particles of this substance may enter the nose, throat and eyes, so it is better to observe safety issues.