what is the difference between a salt shaker and a dredge

It is used to produce caustic soda and chlorine it is also used in the manufacturing processes of polyvinyl chloride, plastics, paper pulp and many other products. The greatest single use for salt (sodium chloride) is as a feedstock for the production of chemicals. Salt is processed from salt mines, and by the evaporation of seawater ( sea salt) and mineral-rich spring water in shallow pools. Salt is used in religious ceremonies and has other cultural and traditional significance. The scarcity and universal need for salt have led nations to go to war over it and use it to raise tax revenues. Salt became an important article of trade and was transported by boat across the Mediterranean Sea, along specially built salt roads, and across the Sahara on camel caravans. Salt was also prized by the ancient Hebrews, Greeks, Romans, Byzantines, Hittites, Egyptians, and Indians. Some of the earliest evidence of salt processing dates to around 6000 BC, when people living in the area of present-day Romania boiled spring water to extract salts a salt works in China dates to approximately the same period. Salting, brining, and pickling are also ancient and important methods of food preservation. Salt is one of the oldest and most ubiquitous food seasonings, and is known to uniformly improve the taste perception of food, including otherwise unpalatable food. Salt is essential for life in general, and saltiness is one of the basic human tastes. In the form of a natural crystalline mineral, salt is also known as rock salt or halite. In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). For other uses, see Salt (disambiguation). For table salt used in chemistry, see Sodium chloride. For salts in chemistry, see Salt (chemistry).

What is the difference between a salt shaker and a dredge