Rare earth potassium sulfates

Potassium pentachloronitrido-osmate(VI), 6 206 Potassium permanganate, solution of, standardization of, for determination of average atomic weight of rare earth elements in oxalates, 2 60, 61 Potassium pyrosulfite, 2 166 and its f-hydrate, 2 165, 167 Potassium rare earth sulfates, 2 47 Potassium selenocyanate, 2 186 Potassium sulfites, KHSO , in solution, 2 167... 

In the year 1886 Lecoq de Boisbaudran separated pure holmia into two earths, which he called holmia and dysprosta. He accomplished this by fractional precipitation, first with ammonium hydroxide and then with a saturated solution of potassium sulfate, and found that the constituents of impure holmium solutions precipitate in the following order terbium, dysprosium, holmium, and erbium (3, 37, 48). Lecoq de Boisbaudran never had an abundant supply of raw materials for his remarkable researches on the rare earths, and he once confided to Professor Urbain that most of his fractionations had been carried out on the marble slab of his fireplace (56). 

Scandium is usually present in rare earth minerals in small amounts (the rare mineral thortveitite containing 37 per cent SC2O3 is an exception). It collects in the soluble end of the bro-mate fractionations, but it is easily separated from the other soluble salts by the fact that it is the least basic of the whole group. Consequently, fractional precipitation or fusion of the nitrates concentrates the scandium rapidly. Scandium may also be precipitated from boiling acid solution by sodium silicofluoride its double ammonium tartrate and double potassium sulfate are also difficultly soluble. 

Potassium Sulfate Rare Earth Oxides Rock Salt... 

Water s great versahlity stems, in part, from a tendency TO form aqueous SOLUHONS by DISSOLVING A LARGE VARIETY OF SOLIDS AND OTHER LIQUIDS THE FACT THAT IT EXISTS AT NORMAL AIR TEMPERATURE AS A LIQUID IS DUE TO THE UNIQUE PROPERTY OF ITS MOLECULES. Even though water covers 70 percent of Earth s surface, IT IS RARE TO FIND PURE WATER IN NATURE. SeAWATER AND FRESHWATER SOURCES ALIKE CONTAIN DISSOLVED MINERALS AND CONTAMINANTS SUCH AS FERHLIZERS AND INDUSTRIAL POLLUTANTS. AS FOR THE WATER THAT COMES FROM THE TAP, IT GENERALLY CONTAINS FLUORIDES (ADDED TO REDUCE TOOTH DECAY) IN ADDIHON TO MINERALS (PRINCIPALLY CHLORIDES, SULFATES, BICARBONATES OF SODIUM, POTASSIUM, CALCIUM, AND MAGNESIUM), AND POSSIBLY ADDIHONAL CHLORINE (TO KILL BACTERIA) AND LEAD (IF THE PIPES CARRYING IT ARE MORE THAN 80 YEARS OLD). 

Rubidium is not too rare in the earth crust, being more abundant than lead. As stone melts crystallized when the earth s crust was formed, rubidium followed potassium in all minerals, as the ionic radii of these two elements are very similar. Consequently there are no typical rubidium minerals. This has been discussed in Chapter 4, Geochemistry. LepidoHte, a hthium-rich mica, is an exception. In that mineral, rubidium can substitute for lithium to such a great extent that as much as 2.5% may be present. One such source is the pegmatite at Bemic Lake, Manitoba in Canada. From mines there, a rubidium-containing lepidolite fraction is obtained and separated as a by-product However, this is not a very profitable business. The demand for rubidium in the whole world is only about 2 tonnes per year and this quantity is obtained in a few hours at Bemic Lake [13.1]. This lepidolite is worked in chemical plants in the US. From the mixed alkali carbonates, rubidium is isolated as sulfate or chloride by advanced separation processes. 

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