Production conditions and applications of super-heavy soda ash
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This post was last edited by mkp369 on January 6, 2014, at 21:25. There are light-weight soda ash, heavy-weight soda ash, and extra-heavy-weight soda ash. The bulk density of light-weight soda ash is 0.45–0.7 g/cm³; that of heavy-weight soda ash is 0.8–1.2 g/cm³. For extra-heavy-weight soda ash (heavy ash, Na₂CO₃), its bulk density ranges from 1.2 to 1.6 g/ml. The production conditions and applications of light soda ash and heavy soda ash are well-known to most people. I would like to ask the experts here: 1. The production control conditions for ultra-heavy soda ash. We know that heavy lime is produced by the liquid-phase hydration method by forming monohydrate alkali crystals and then separating and drying them. Therefore, under liquid-phase conditions, to obtain sodium carbonate crystals, the temperature must be maintained above 106 degrees Celsius; how can this process be implemented in an engineering context, and how can separation and drying in subsequent steps be carried out effectively? 2. Or is super-heavy pure soda produced using other processes? 3. Light soda ash, due to its low density and fine particles, is easy to dissolve in water; its water solubility is much higher than that of heavy soda ash. It is primarily used in industries such as detergents, food additives, chemical products, and paper manufacturing, where dissolution in water is necessary for its use. Heavy soda ash is further divided into heavy ash and low-salt heavy soda ash. It has advantages such as high density, moderate particle size, low dust generation, resistance to scarring, and reduced costs associated with packaging and transportation. Its use in the steelmaking industry and glass production can extend the lifespan of reaction furnaces. Low-salt heavy soda ash features large crystal particles and low chloride content, and is mainly used in the production of high-quality glass, lenses, and cathode ray tube envelopes. What I want to ask is: since super-heavy soda ash is a category of soda ash, it must have special uses – where is it mainly used? At present, which soda ash manufacturers, both domestic and international, are producing such products?
Is there any production of super-heavy soda ash in China? I’ve never heard of it.
This post was last edited by mkp369 on January 6, 2014, at 21:31. Physical properties: Appearance: a white, granular anhydrous substance; readily soluble in water. When exposed to air at room temperature, it absorbs CO2 and water, releasing heat in the process; it gradually transforms into NaHCO3 and forms lumps. Molecular formula: Na2CO3. Specifications: Total alkali content (expressed as Na2CO3) ≥99.2%; Chlorides (expressed as NaCl) ≤0.25–0.4%; Iron (expressed as Fe2O3) ≤0.004%; Water-insoluble substances ≤0.04%; Loss on ignition ≤0.5%. Bulk density (KG/M3): 900–1000. Use: One of the important basic chemical raw materials. It is widely used in fields such as chemicals, metallurgy, national defense, textiles, printing and dyeing, food, glass, enamel, pharmaceuticals, and papermaking. Production method: (1) Ammonia-alkali process (Solvay process): Using raw salt and limestone as raw materials, light soda ash is produced through chemical synthesis, while heavy soda ash is produced via the solid-phase hydration method. (2) Trona method: Using trona as a raw material, heavy soda ash is produced through evaporation or carbonization methods. It has many uses; generally, its alkalinity is utilized. It can be used to manufacture glass, such as flat glass, bottle glass, optical glass, and high-end utensils ； Soap can also be made by utilizing the reaction between fatty acids and soda ash ； It is used in the softening of hard water, the refining of petroleum and oils, the removal of sulfur and phosphorus in the metallurgical industry, mineral processing, as well as in the production of metals such as copper, lead, nickel, tin, uranium, and aluminum. It is also employed in the chemical industry for the manufacture of sodium salts, metal carbonates, bleaching agents, fillers, detergents, catalysts, and dyes. In the ceramic industry, soda ash is used to produce refractory materials and glazes. It is an important heavy-duty chemical raw material. Production methods include the Solvay process①, the Hou’s alkali production method②, and the processing of natural soda, with the raw materials varying depending on the processing method used. The main raw materials include crude salt (including sea salt, pond salt, mineral salt, and underground brine), soda ash, limestone, ammonia, etc. The main soda ash manufacturers in China include the Dalian Chemical Industry Company’s soda ash plant, Tianjin Soda Ash Plant, Qingdao Soda Ash Plant, Zigong Honghe Chemical Complex, and Hubei Chemical Factory.
I really haven’t heard of any company in China that produces ultra-heavy soda ash!
Are you doing science popularization? Isn’t this information a bit too old? :D
What I want to ask about is the production of super-heavy soda ash, not the production of light ash and heavy ash. That is, before the separation of the mother liquor from the crystals, these crystals are not hemi-base crystals or monohydrate base crystals, but rather anhydrous base crystals. (I think it must be such a crystal structure in order to produce products with a high bulk density.) ) Thank you to everyone up there for participating.
The idea that, before the separation of the mother liquor from the crystals, those crystals are not monohydrate alkali nor hemihydrate alkali but rather anhydrous alkali is completely unfounded. In the current process of producing heavy soda ash using monohydrate alkali, when conditions such as temperature and pressure are not properly controlled, anhydrous alkali crystals can form. During the solid-liquid separation process, these crystals tend to stick to the separation equipment and the downstream conduits. When placed in the air, they absorb moisture from it immediately, and as the temperature drops, they turn into hard lumps; this represents abnormal production conditions. This is a problem that currently baffles many manufacturers.
Anhydrous alkali crystals can form when conditions such as temperature and pressure are not properly controlled. This is exactly the control condition I was looking for! If these abnormal process conditions are transformed into normal, long-term control parameters, then the crystals grown under such conditions, even if they have water on their surface, will not completely convert into monohydrate alkali inside their crystal structure during separation, right? I think the key to the problem is to allow the crystals to grow under these conditions, rather than separating them as soon as fine crystals are formed.
The production process of monohydrate soda involves producing the crystals of monohydrate soda, followed by solid-liquid separation, and then obtaining soda ash through calcination. Under normal temperature and pressure conditions, the crystal formed is monohydrate alkali; accidental factors can lead to the formation of anhydrous alkali crystals, which affects production. I don’t think what you’re saying – namely, producing super-heavy soda ash by generating anhydrous alkali crystals – is feasible; after all, there are too many difficulties associated with using anhydrous alkali crystals in production, and these difficulties are not easy to overcome. Anhydrous alkali crystals cause severe scarring on the evaporation chamber and the heating compartment; during subsequent centrifugation, they stick to the rotating blades, and when they adhere to the alkali discharge pipes, these pipes get blocked. Once they enter the calcination furnace, they stick to the heating tubes, leading to serious scarring of those tubes. This series of problems is difficult to resolve and makes it hard to achieve the desired outcome.
The formation of anhydrous alkali crystals is abnormal, and it is very difficult to turn this abnormal condition back into a normal one. It’s just like how it’s difficult for a normal person to become insane, and it’s equally hard for an insane person to return to a normal state.