I’m facing technical issues related to the purification of secondary brine for ion-exchange membrane caustic soda production, with an annual output of 20,000 tons. I hope everyone can help; thank you.
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This post was last edited by sunjl1981 on 2013-1-7 00:26. I need to work on a graduation project, but I don’t know how to write. Knowing the formula for calculating the output of caustic soda, how is the amount of raw salt determined? And then what formula is used to determine the amount of saline that needs to be processed per hour? Also, can other ions besides calcium and magnesium ions, such as mercury ions, nickel ions, and iodide ions, be removed during the purification of brine by adding sodium hydroxide or sodium carbonate? Are there any other refined products? There are quite a few questions; if you know any of them, please think about them for me. Thank you all. This post was last edited by limingshuguang on 2009-4-18 19:09 ] # hcbbs
Dowell clarified that it is also necessary to remove sulfate ions from the barrel, add a flocculant, and add hydrochloric acid during the neutralization of the saltwater after filtration. Membrane filtration requires ferric chloride, sodium hypochlorite, and sodium sulfite. That seems to be all
This issue is too complex; it’s recommended that the original poster first study the relevant content on the forum before posting to discuss it with others. For reference: 1. Discussion on impurities in saline, metal ions ； 2. Discussion on anions in saline solution ； 3. Discussion on organic compounds ； 4. Preparation and discussion of the secondary saline solution.
The calculation for ion-exchange membrane caustic soda is based on the following formula: NaCl + 2H2O = NaOH + 1/2H2 + 1/2Cl2. The relevant values are as follows: 58.5, 36, 40, 1, 35.5; n1, n2, 1000, n3, n4. The amount of raw salt required is n1 = 1462.5 kg, n2 = 900 kg. The amount of hydrogen produced is n3 = 25 kg, while the amount of chlorine produced is n4 = 887.5 kg. These are merely theoretical values; there are also complex side reactions during the electrolysis process.
To calculate the volume of brine processed: For each ton of caustic soda produced, 262 kg of water is carried away by chlorine, and 1000/40*4*18 = 1800 kg of water enters the cathode along with sodium ions. The volume of brine entering the system is n5, with a concentration of 310 g/l and a specific gravity of 1.15. The volume of brine exiting the system is n6, with a concentration of 200 g/l and a specific gravity of 1.10. The amount of raw salt required is 1462.5 kg. Thus, n5*310 = 1462.5 + n6*200.
For salt balance: n5*1150 – n5*310 = 262 + 1800 + n6*1100 – n6*200.
For water balance: It needs to be calculated separately. Generally, 9 cubic meters of refined brine are required per ton of caustic soda produced. Refined treatment is used to remove calcium, magnesium, and strontium; other effects are less significant. Excessive iron levels can cause poisoning of the resin
To calculate the volume of brine processed: For each ton of caustic soda produced, 262 kg of water is carried away by chlorine, and 1000/40*4*18 = 1800 kg of water enters the cathode along with sodium ions. The volume of brine entering the system is n5, with a concentration of 310 g/l and a specific gravity of 1.15. The volume of brine exiting the system is n6, with a concentration of 200 g/l and a specific gravity of 1.10. The amount of raw salt required is 1462.5 kg. Thus, n5*310 = 1462.5 + n6*200.
For salt balance: n5*1150 – n5*310 = 262 + 1800 + n6*1100 – n6*200.
For water balance: It needs to be calculated separately. Generally, 9 cubic meters of refined brine are required per ton of caustic soda produced. Refined treatment is used to remove calcium, magnesium, and strontium; other effects are less significant. Excessive iron levels can cause poisoning of the resin
Sorry, I forgot to include the 900 kg of water that was removed through electrolytic decomposition