Stassfurt salts

Discovery of Stassfurt salt deposits opened the way for bromine production (for photography and... 

Bromine was formerly obtained from the mother liquid remaining after the separation of sodium chloride from sea-water, a certain proportion of bromine was also extracted from the lixivium of the ash of seaweed, but the proportion in seaweed is small—about one-tenth that of the iodine. The manufacture of bromine from the brine springs of America was commenced at Freeport in 1846 by D. D. Alter and the manufacture from the saline waters about Stassfurt1 was commenced in Germany in 1865. The discovery that bromine could be profitably extracted from the Stassfurt salts reduced the price of that element from about 38s. 0d. to Is. 3d. per lb. 

Formerly all the iodine was made from the ash of seaweed, and potash was a remunerative appendix to the iodine industry but just as the Stassfurt salts killed those industries which extracted potash from other sources, so did the separation of iodine from the caliche mother-liquors threaten the industrial extraction of iodine from seaweed with extinction. Iodine in a very crude form was exported from Chili in 1874—e.g. a sample was reported with iodine 52-5 per cent. iodine chloride, 3-3 sodium iodate, 13 potassium and sodium nitrate and sulphate, 15 9 magnesium chloride, 0 4 insoluble matter, 1 5 water, 25-2 per cent. About that time much of the iodine was imported as cuprous iodide. This rendered necessary the purification of the Chilian product but now the iodine is purified in Chili before it is exported. The capacity of the Chilian nitre works for the extraction of iodine is greater than the world s demand. It is said that the existing Chilian factories could produce about 5100 tons of iodine per annum whereas the... 

The composition of the Stassfurt salt beds.—The deposits about Stassfurt may very roughly be grouped in a series of strata indicated in Fig. I.13 Starting from a basal layer of anhydrite and gypsum there are ... 

Uses Of the Stassfurt salts.—The magnesium compounds in the Stassfurt salts are used for the preparation of magnesium and of its salts. The potash salts are an essential constituent of many fertilizers used in agriculture, etc. 22 and potassium chloride is the starting-point for the manufacture of the many different kinds of potassium salts used in commerce—carbonate, hydroxide, nitrate, chlorate, chromate, alum, ferrocyanide, cyanide, iodide, bromide, etc. Chlorine and bromine are extracted by electrolysis and other processes from the mother liquids obtained in the purification of the potash salts. Boric acid and borax are prepared from boracite. Caesium and rubidium are recovered from the crude carnallite and sylvite. 

Wood ashes.—The ash of wood, not coal, contains about 30 per cent, of potassium carbonate. Prior to the exploitation of the Stassfurt salts about the middle of the nineteenth century, the chief source of potash was wood ashes, and the process is still used in certain localities where wood-fuel is employed and where much waste wood is available—e.g. in some parts of Canada, United States, Russia, Spain, etc. The ash of trees, hedge-cuttings, sawdust, etc., can be made to yield potash.5 In the Caucasus, the sunflower is grown on waste land for the sake of its seed. The stalks, leaves, etc., are a by-product and are burnt the ash is used as a source of potash. Nearly 7000 tons per annum of crude potash from this source were exported from Novorossik in Russia. The residues in the manufacture of olive oil and almond shells are also stated by G. l Abate to be exceptionally rich in potash salts F. W. F. Day claims that the roots of the water hyacinth (eiehornia crassipes) have... 

Sylvine or sylvite occurs in the Stassfurt salt deposits, and it is associated with halite or rock-salt in volcanic salts in the salt-mines of Hallem (Salzburg), Kalusz (Galicia), Mayo (Punjab), Asnapuquio (Lima, Peru), and many other places. 

Occurrence.—Rubidium is widely distributed in nature, being found in small quantities in association with the other alkali-metals. It constitutes about 1 per cent, of lepidolite, and is present in the Stassfurt salt deposits, in the soil, in many natural waters, and in the ashes of numerous plants. 

Occurrence.—The principal mineral containing caesium is pollucite, a double silicate with aluminium having the approximate composition Cs4AI4H2Si9027, found in Maine and in Elba.1 It accompanies the other alkali-metals, being found in traces in the Stassfurt salt deposits and in many mineral springs. 

Bromine was discovered in 1826 by Balard, who extracted it from saline mother-liquors. It has since been obtained also from the ash of algae, but nowadays is obtained almost exclusively from the Stassfurt salt deposits and from saline mother-liquors. 

The bromine industry has grown considerably in recent years with the utilisation of that in the mother-liquors from the Stassfurt salts in Germany and of that in saline mother-liquors in America. 

Bromide therapy introduced by Lacock as a sedative and anticonvulsant for treatment of epilepsy Discovery of Stassfurt salt deposits opened the way for bromine production (for photography and medicine) as a by-product of potash... 

---