IODIZED SALT

Chemical Makeup:

Production:

Additives:

Refined salt is 99.5% NaCl and is dry and white with a uniform grainsize (0.3- m m) and depending on the application it is solid with or without additives such as:

1. Anti-Caking agents: prevents adjacent grains from cementing together to form a solid mass (Potassium or Sodium ferrocyanide are added)

2. Free Flowing agents: provides crystals with a mechanical coating which acts as a lubricant and absorbs any water vapour within the package after sealing (Manganseium carbonate, Calcium silicate, Sodium silco-aluminate and Tricalcium phosphate are used)

3. Iodizing agents: controls disorders due to iodine deficiency (Potassium iodide or Iodate at a level of 30-170 ppm)

Iodized salt is simply table salt with small amounts of iodine added.

Salt when dissolved in water:

NaCl(s) --> Na+(aq) + Cl-(aq)

The chemical formula for table salt is NaCl or sodium chloride. Iodine is added to iodized salt as one of the following compounds: potassium iodate (IO3K), potassium iodide (KI), sodium iodate (NaIO3), or sodium iodide (NaI).

• Modern salt plants routinely spray potassium iodide or potassium iodate onto the salt while it moves along a conveyor belt before it is packaged. In lower-tech operations, iodine is sometimes added as a dry ingredient and physically mixed with the salt.

• Generally, iodized salt contains 0.002% to 0.004% iodine, supplied either as potassium iodide or potassium iodate.

• Iodine is added as potassium iodide in table salt at slightly higher levels - 0.006% to 0.01% potassium iodide, equivalent to 0.0046% to 0.0077% iodine.

• Animal feeds are fortified with iodine in the form of potassium iodate, the form most commonly used globally to iodize food salt outside the U.S. because of its greater stability. U.S. salt producers add sodium carbonate or sodium bicarbonate when they iodize salt to increase alkalinity, and sodium thiosulfate or dextrose to stabilize potassium iodide. Without a stabilizer, potassium iodide is oxidized to iodine and lost by volatilization from the product.

• Use of adequately iodised salt has increased by 20% in the rural households as against the last country-wide survey conducted under the National Family Health Survey (2005-2006).

• The Iodised Salt Coverage Study 2010 suggests that use of iodised salt in rural India has jumped to 47.3 per cent from 27 per cent.

• Due to awareness campaigns the annual production of iodised salt had increased to 57-lakh (a unit used in South Asia) tonnes from 48-lakh tonnes after the use of iodised salt for consumption was made mandatory in 2005.

IODIZED SALT

Production Processes:

The main objective is to make sure that the salt contains the prescribed amount of iodine and other minerals at the time of consumption.

Processes and Stages of Refining Salt:

• salt feeding
• salt washing + milling
• centrifuging
• dosing of additives + coating
• salt drying
• sizing and conditioning
• storing
• packaging

2 basic processes for refining salt:

• mechanical iodised salt refinery
• vacuum iodised salt refinery

Mechanical Iodized Salt Refinery:

Crude Salt is fed into the feeding hopper of suitable capacity and it is then transferred to a belt conveyor. This belt conveyor will be fitted with a magnet to remove rubbish metal and will also be provided with a belt weigher with totaliser. Crude salt is pre-washed in special washing system. This is then fed to the feed in hopper of the wet mill for grinding. Wet mill is used to grind the salt with the help of saturated brine solution. This mixture is then passed to the slurry tank that is fitted with a low speed agitator. This slurry is then pumped through centrifuges, high pressure pump, centrifugal pumps, axial flow pumps, gear pump to the wash tank by a slurry pump, wherein dirt is removed from the slurry. The overflow from the wash tank is collected in a clarifier wherein brine is clarified and re-circulated in the plant. This is then pumped to the hydro cyclone by a slurry pump for thickening of the slurry.

Centrifuge / Iodisation Section

The overflow is then passed to the wash tank for further processing and the thick slurry is then passed through a Pusher Type centrifuge which separates salt crystals from the slurry and the liquid portion is collected in a filtrate tank. This liquid portion is then pumped to the thickener for further processing. Wet dosing is done in the centrifuge.

Drying & Finished Product Handling Section

The salt crystals from the centrifuge are dried in a Fluid-Bed Dryer. The crystals forms a layer on the perforated sheet present in the drying chamber of the fluid bed dryer and is dried by means of hot air from a thermic fluid air heating/Indirect air heating system. The fines are removed from the exhaust stream in the cyclone separator and is collected separately. Dry salt is from the outlet of the fluid-bed dryer and is passed to the rotary sifter through a bucket elevator. The oversized salt is separated in the sifter and the over sized salt crystals is passed to the pin mill for further grinding and salt is passed to the feed in hopper of the blender wherein free flowing agent is added. This free flowing salt is then sent to the packing room by a belt conveyor

Iodisation & Drying

This slurry is fed to a centrifuge, and from the centrifuge salt cakes with 4-5% moisture comes out. The salt with 4-5% moisture is fed to a fluid bed dryer through a crew conveyor where the iodisation is completed.

The salt packaging is done from the silo by a FFS machine in 1 kg. Packs or it can be packed in 50 kg bags as per requirement.

Vacuum Iodized Salt Refinery:

The process involves dissolving of salt in water and making a saturated solution of salt. The saturated brine is pumped out to a brine clarifier, where the insolubles settles at the bottom of the clarifier and clear brine solution is taken to a brine tank. In the brine tank required chemicals are added to precipitate out magnesium and calcium salts present along with the salt. The brine is then filtered and taken to the final brine tank.

From this tank saturated brine is fed to the continuous evaporation plant where crystalisation takes place and slurry is pumped out to a concentrate tank.

This salt slurry is then pumped to a hydro-cyclone battery to get a slurry concentration up to 50-60%.

This slurry is fed to a centrifuge, and from the centrifuge salt cakes with 4-5% moisture comes out.

The salt with 4-5% moisture is fed to a fluid bed dryer through a crew conveyor where the iodisation is completed.

In the Vibro Fluid Bed Dryer the salt is fluidized by hot and atmospheric air for drying and cooling the salt.

The salt is then taken through a bucket elevator to a sieving machine. The oversize particles are collected and sent for re-dissolving in the final brine tank.

To the cystallined salt is then added the free flowing agent in a screw mixer and finally sent to a storage silo.

The salt packaging is done from the silo by a FFS machine in 1 kg. Packs or it can be packed in 50 kg bags as per requirement.

Quick Salt Facts:

• The levels and types of impurities, moisture content and pH of salt produced for human consumption vary widely.

• Salt is produced from sea water, rock salt deposits and lake sediments, by solar evaporation of brines and dry or solution mining of rock salt deposits.

• Refining processes range from simple washing methods to large-scale mechanized vacuum evaporation systems which require trained operators and rigorous quality assurance.

Salt In Our Diet:

• 90% of the sodium we eat comes in the form of salt.

• 77% of a person’s salt intake comes from restaurant or processed food; only 6% is added at the table and only 5% during

cooking.

• Many foods that contribute a significant amount of sodium in the diet do not taste particularly salty, such as breads and cheeses. Some of these foods are deceptively high in salt; others are lower in salt content but frequently consumed.

Note: it can be spelled iodized or iodised

Rank Country/Region 2006 salt production (tonnes) % of world production

The Environment:

World 210,000,000 100 %

1 United States 46,500,000 22.14 %

2 China 37,101,000 17.67 %

3 India 15,000,000 7.14 %

4 Canada 14,125,000 6.73 %

5 Australia 11,211,000 5.34 %

6 Mexico 8,180,000 3.9 %

7 France 7,000,000 3.33 %

8 Brazil 6,500,000 3.1 %

9 Chile 6,000,000 2.86 %

10 United Kingdom 5,800,000 2.76 %

11 Netherlands 5,000,000 2.38 %

12 Italy 3,600,000 1.71 %

13 Spain 3,200,000 1.52 %

14 Russia 2,800,000 1.33 %

15 Iran 2,618,000 1.25 %

16 Romania 2,450,000 1.17 %

17 Egypt 2,400,000 1.14 %

18 Ukraine 2,300,000 1.1 %

19 Turkey 2,250,000 1.07 %

20 Bulgaria 1,800,000 0.86 %

21 Poland 1,600,000 0.76 %

22 Pakistan 1,320,000 0.63 %

23 Vietnam 1,300,000 0.62 %

24 Japan 1,251,000 0.6 %

25 Argentina 1,200,000 0.57 %

26 Thailand 1,000,000 0.48 %

27 Bahamas 900,000 0.43 %

28 Israel 800,000 0.38 %

29 South Korea 800,000 0.38 %

30 Germany 746,000 0.36 %

31 Namibia 700,000 0.33 %

32 Indonesia 680,000 0.32 %

33 Denmark 610,000 0.29 %

34 Tunisia 608,000 0.29 %

35 Philippines 600,000 0.29 %

36 Portugal 600,000 0.29 %

37 Colombia 540,000 0.26 %

38 Netherlands Antilles 500,000 0.24 %

39 North Korea 500,000 0.24 %

40 Jordan 410,000 0.2 %

41 Austria 401,000 0.19 %

42 Bangladesh 350,000 0.17 %

43 Venezuela 350,000 0.17 %

44 South Africa 336,000 0.16 %

45 Belarus 300,000 0.14 %

46 Switzerland 300,000 0.14 %

47 Ghana 250,000 0.12 %

48 Peru 249,000 0.12 %

49 Morocco 240,000 0.11 %

50 Turkmenistan 215,000 0.1 %

51 Botswana 208,000 0.1 %

52 Martinique 200,000 0.1 %

53 Saudi Arabia 200,000 0.1 %

54 Cuba 185,000 0.09 %

55 Algeria 183,000 0.09 %

56 Greece 150,000 0.07 %

57 Syria 146,000 0.07 %

58 Senegal 130,000 0.06 %

59 Slovenia 125,000 0.06 %

60 Yemen 120,000 0.06 %

61 Kuwait 100,000 0.05 %

62 Slovakia 100,000 0.05 %

Things have changed since the 1920′s with the manufacturing of toxic chemicals and more cost effective ways of harvesting salt. Most of the salt harvested then was natural salt from the sea or from natural salt deposits and contained the beneficial trace mineral iodine.

Table Salt or “Iodized Salt” is not a healthy naturally occurring rock, crystal or sea salt. It is a manufactured type of sodium called sodium chloride with added iodide.

Iodine in salt is available at grocery stores, restaurants and in practically all processed foods, have synthetic chemicals added to them. These chemicals may include manufactured forms of iodide, sodium solo-co-aluminate, fluoride sodium bicarbonate, toxic amounts of potassium iodide, anti-caking agents and aluminium derivatives. Table salt has also been bleached. Unfortunately, most table salt is not only unhealthy, but is toxic to the body and should never be considered as a source of healthy iodine.

Salt found in nature is not usually white it is pink in color

such as Himalayan Crystal salt which is harvested in pristine

mountains and naturally dried in the sun.

Of course, salt today is still derived from natural sources, and things like “anti-caking” agents have been added for decades, because, without them, salt would solidify and not pour properly due to moisture. Salt in nature can be any number of colors, as a result of impurities. Sodium Chloride is and always was the primary component of salts used in foods. It’s the primary component of both sea and rock salts.

Why Do We Need Iodized Salt?

• Humans require trace amounts of iodine, for proper development and growth.

• It exists in most soils, and is taken up by plants which are in turn ingested by humans and animals.

• Most of the body's iodine storage places are in the thyroid gland, which requires the mineral for synthesis of the hormones it secretes.

An iodine deficiency leads to an enlarged thyroid gland (goiter), slowed metabolism, and weight gain, as well as other symptoms of hyperthyroidism such as fatigue and intolerance of cold, as well as neurological, gastrointestinal, and skin abnormalities. Iodine deficiency in pregnant or nursing mothers can result in thyroid problems during fetal and child development, and is the most common cause of preventable brain damage in the world.

• Iodine was first added to salt in the United States in 1924 in order to eliminate goiter.

• Goiter, due to iodine deficiency, is still common in parts of central Asia and central Africa - areas where iodine-rich foods are not available.

• We can get iodine naturally by eating saltwater fish and seafood, kelp and other sea vegetables as well as vegetables grown in soils that contain iodine. Dairy products also provide iodine if the animals graze on plants growing in iodine-rich soils.

• We need 150 mcg or more (pregnant women need to make sure they're getting adequate iodine for the health of their babies). Daily intakes of up to 1,100 mcg daily for adults and children over four are considered safe.

• There is unrefined (gray) and refined (white) sea salt, which is often preferred to commercial salts that often have additives, such as aluminum compounds to prevent caking. Sea salt contains trace amounts of iodine.