1. Done by: Li Shida (1O2)

2. Definitions Brine solution: H2O + NaCl (water + salt) Commercially (In This Case): Methods that are used to obtain NaCl is suitable for commercial uses.

3. 3 Main Methods Solar Evaporation Rock Salt mining Vacuum Evaporation

4. Solar evaporation Oldest Method First observed in sea water caught in holes and evaporate to form salt as a natural process Was manually done by our ancestors to obtain salt Commercialized now days Evaporation, Filtration and Crystallization used

5. Step 1 Step 1: Diverge large amounts of sea water into salt ponds. The ponds must be large in total area for commercial production.

6. Step 2 Step 2: Wait for natural evaporation This process might take 2 years Concentration of water causes crystallization Chemicals such as calcium carbonate will crystallize first and will be removed Sunshine and wind are key factors. The more of these, the faster the evaporation will take place.

7. Step 3 Step 3: Removal of brine solution into crystallizing ponds The saturated salt solution will be filtrated and pumped into crystallizing ponds Other impurities that are not dissolved will be drained away

8. Step 4 Step 4 : Crystallization & final cleaning All water will evaporate in the crystallization ponds, forming solid NaCl of purity more than 99.7% The NaCl will then be washed with brine solution. Since no salt can dissolve more in the brine solution, there will be no loss 99.8% purity of NaCl is finally obtained

9. Separation Methods used Filtration: Impurities that can affect the quality of NaCl production is removed Evaporation: Saves energy as compared to manual heating. Concentrates water Crystallization: To obtain almost pure dry NaCl, the final product

10. Diverge Sea water into evaporation ponds (~3.5% concentration) Removal of impurities Natural Evaporation (~99.7% concentration ) Crystallization & Final cleaning

11. Method 2: Rock Salt Mining Second oldest method Mines rock salt underground 2 types of rock salt deposit: Vein form and dome form Vein form: salt deposit spreads over a large area like veins Dome form: Salt chunked together in large amounts

12. Step 1 Step 1: Locating & Blasting After a salt deposit is located, explosives will be used to make them fall to the ground. Older methods such as mining was also used.

13. Step 2 Step 2: Crushed into manageable chunks & hauled to the surface Transportation of rock salt requires it to be smaller in size

14. Step 3 Step 3: Screening The rock salt is screened to make sure that its quality is of standard. Some minerals must be removed because it might be harmful. A brine solution might also be used to treat it. The solution might also be filtrated to leave the rock salt as the residue. 99. 8% purity of NaCl is obtained

15. Methods used & Process Filtration: Filters the unwanted minerals away. Important for quality control of the salt. Locating and Blasting Crushing and Hauling Screening

16. Vacuum Evaporation Dissolving rock salt or solar salt in water to create a brine solution, then boiling off the water to leave behind pure salt. Newest and most high-tech method Lowers atmospheric pressure to lower boiling point Can increase purity to 99.99%

17. Step 1 Step 1: Dissolving Rock salt or solar salt is dissolved to obtain a brine solution Normally done in large amounts

18. Step 2 Step 2: Boiling The brine solution will be pumped into a vacuum The boiling point lowers since there is less atmospheric pressure in a vacuum Water is boiled away to obtain 99.99% purity of NaCl

19. Interesting facts about vacuum evaporation Purifies salt to meet high standards of purity The vacuum “boiling pots” can be stacked together, with pots on top having a lower atmospheric pressure than pots below. The water vapor from the lower ones can cause the upper one to boil, saving energy and money

20. Methods used & process Evaporation: Separation of NaCl and H2O was very important and evaporation does the job well DissolvingBoiling

21. Bibliography http://www.scribd.com/doc/17490071/How-is-Salt- Produced http://www.scribd.com/doc/17490071/How-is-Salt- Produced http://www.saltinstitute.org/Production- industry/Production-technologies/Solar-salt-sea-salt http://www.saltinstitute.org/Production- industry/Production-technologies/Solar-salt-sea-salt http://www.mortonsalt.com/salt-facts/salt-production- and-processing http://www.mortonsalt.com/salt-facts/salt-production- and-processing http://www.bigsiteofamazingfacts.com/how-is-salt- made http://www.bigsiteofamazingfacts.com/how-is-salt- made http://www.madehow.com/Volume-2/Salt.html http://www.cargill.com/salt/about/howsaltismade/ind ex.jsp http://www.cargill.com/salt/about/howsaltismade/ind ex.jsp