Refined salt has the minerals stripped away.

^Refined salt, which is most widely used presently, is mainly sodium chloride. Food grade salt accounts for only a small part of salt production in industrialised countries (3% in Europe[20]) although worldwide, food uses account for 17.5% of salt production.[21] The majority is sold for industrial use. Salt has great commercial value because it is a necessary ingredient in the manufacturing of many things. A few common examples include: the production of pulp and paper, setting dyes in textiles and fabrics, and the making of soaps and detergents.

The manufacture and use of salt is one of the oldest chemical industries.[22] Salt can be obtained by evaporation of sea water, usually in shallow basins warmed by sunlight;[23] salt so obtained was formerly called bay salt, and is now often called sea salt or solar salt. Rock salt deposits are formed by the evaporation of ancient salt lakes,[24] and may be mined conventionally or through the injection of water. Injected water dissolves the salt, and the brine solution can be pumped to the surface where the salt is collected.

After the raw salt is obtained, it is refined to purify it and improve its storage and handling characteristics. Purification usually involves recrystallization. In recrystallization, a brine solution is treated with chemicals that precipitate most impurities (largely magnesium and calcium salts).[25] Multiple stages of evaporation are then used to collect pure sodium chloride crystals, which are kiln-dried.

Since the 1950s it has been common practice in the United Kingdom to add a trace amount of sodium ferrocyanide to the brine; this acts as an anticaking agent by promoting irregular crystals.[26] The safety of sodium ferrocyanide as a food additive was confirmed in the United Kingdom in 1993.[27] Some anti-caking agents used are tricalcium phosphate, calcium or magnesium carbonates, fatty acid salts (acid salts), magnesium oxide, silicon dioxide, calcium silicate, sodium aluminosilicate, and calcium aluminosilicate. Both the European Union and the United States Food and Drug Administration (FDA) permited the use of aluminum in the latter two compounds.[28] The refined salt is then ready for packing and distribution.^

Medical science is always behind in everything. Only now are they beginning to recognize that purifying the hell out of everything is not always beneficial. How long did it take them to realize that eggs were really OK to eat after they panicked over the cholesterol present in the egg. Of course, the egg also had lecithin in it which is what the body needs to properly metabolize the cholesterol. Benefits of lecithin.

^One way lecithin aids in preventing or reversing certain diseases and conditions is that since it is predominately comprised of fat itself, it adheres to our cell and nerve linings, forming a sheath, and prevents cholesterol and other fats from sticking. By doing this, in the case of patients with high cholesterol, it decreases the body’s ability to absorb cholesterol across the intestinal wall, thus lowering total cholesterol, including LDL’s (low-density lipoprotein cholesterol). With the reduction of blood cholesterol, research has also shown to reverse atherosclerosis, which is the hardening of the arteries. Though there are pharmaceutical products on the market that control and aid in the control of these diseases, lecithin, is capable of doing this in a much more natural way and at a much cheaper price.
^
Of course, it's a wonder they haven't removed the lecithin from eggs yet. If it were found that the removal would make eggs last one day longer, they would!