Monday, October 1, 2012

Ways Of Extracting Salt From Sea Water

Sea salt is used in body care products, like bath salts.


Sea salt is used as an ingredient in cooking as well as for skin care and alternative healing practices. Since many brands of sea salt are not chemically altered to wash out many of the minerals, this salt is much healthier than processed table salt. The minerals from sea salt are minerals that the human body needs. Harvesting sea salt is a long process, though the yields are usually very large. Sea salt can be harvested in several ways.


Sun Harvesting


Sun harvesting is one way to mass-harvest sea salt directly from the ocean. Shallow rectangles are dug into the ground and lined with clay or stone. Sea water is poured into these shallow rectangles or allowed to wash into them directly from the sea. The sun beats down on the shallow pools of sea water, slowly evaporating the liquid. As the liquid evaporates, salt begins to float to the surface or appear in small piles. Workers drag wide wooden hoes through the water to rake up the salt and shovel it into containers to be gently rinsed and readied for packaging.


Vertical Field


This technique is used to make temomi tenpien enmusubi, a salt native to Japan. Sea water is harvested and filtered a minimum of four times to remove impurities and prevent bacteria growth. It is then poured into a large, cedar cylindrical tower equipped on the inside with waterproof cloth to protect the cedar and many criss-crossing screens of black cloth. The seawater is continuously drawn up and poured through these screens while being subjected to heavy air flow and heat provided by fans and heaters inside the vertical field. Salt begins to dry and crystallize on the cloth filters and is harvested when the layers become thick. This technique yields as much salt as other techniques in a shorter amount of time.


Salt Pot


Use of salt pots dates back to ancient Japan. The pots were usually made of iron and very large to yield a lot of salt at one time. Villagers would harvest water from the Inland sea and let the sun evaporate much of the water until the mixture was very dense and salty. Then, they dried large pieces of seaweed on the beach sand and added them to the salt pot where they then poured the reduced sea water.


The iron salt pot was then placed over a fire and heated. The water began to evaporate and the salt stuck to the seaweed, creating a thick mixture. The ancient Japanese continued heating the mixture until all of the water was gone and the seaweed reduced to ash. Today, the thick mixture is removed to modern centrifuges where the salt is extracted from the remaining water and seaweed through gravity force.







Tags: directly from, poured into, salt minerals, salt used, then poured, thick mixture