Kelp is a name given to _____ ?

Following is a process of extraction of iodine.Sea weeds contain about 0.5 percent iodine in the form of iodides.Sea weeds, particularly of laminaria variety, are collected, dried and burnt in shallow pits so as to avoid any loss of iodine. The ash known as kelp contains about 0.4-1.3% iodine as iodates in addition to chlorides and sulphates.