| OCR Text |
Show TESTS FDR POTASH ISSUED BY SURVEY I Domestic Scarcity Drives Potash From $35 to $425 Per Ton. SALTS IN DEMAND Small Amount Produced in United States in 1915 Valued at $342,000. The domestic scarcity of potash salts I in the United States has resulted in the I price advancing from $35 to as higli as 5425 per ton, according to a bulletin issued is-sued by the United States geological survey, sur-vey, entitled "Potash Salts. 1915." The bulletin was written by W. C. Phalen ; and it contains tests by which prospectors may determine the potash material in tho field. Tlie tests are by W. B. Hicks of j the survey. Tlie amount of soluble salts ! produced in the United States in 1915 was valued at $342,000, which amount in j normal times is consumed in less than a , week. The value of the salts imported during the year was more than $3765. Potash is used as a fertilizer. Potassium is generally found in nature In solution as soluble salts, or saline residues, in organic substances, in alunite and in silicate rocks and minerals. The tests given in tlie bulletin depend on the fact that when a volatile potassium compound com-pound is heated in a flame it imparts a characteristic violet color to the flame. Since sodium and calcium mask the violet vio-let color, it is identified by observing the flame through a Merwin color screen. Tests for Potassium. Mr. Hicks says in part: The equipment necessary for making mak-ing the tests consists of the following: follow-ing: An ordinary alcohol lamp, or gasoline gaso-line or blast lamp; a platinum wire about four inches long, one end of which is bent in the form of a loop; a Merwin color screen, a small beaker, hydrochloric acid and gypsum or calcium cal-cium sulphate. Waters and brines are tested by dipping dip-ping the platinum wirp in the hydrochloric hydro-chloric acid and holding it in the flame until the flame is no longer colored. By means of the clean platinum loop remove a drop of the solution to be tested, . carefully evaporate evap-orate it to drvness bv holding it over the flame; finally. Ignite and observe the color of the flame through the Merwin color screen. The best results are obtained by using a black background, back-ground, holding the color screen close up against the eyes and looking through the central section of the screen. If potassium salts are present pres-ent the flame will appear reddish to reddish violet and the intensity and duration of the color will give some idea as to the amount of potassium. In Clays and Muds. For detecting potassium in saline j residues, or soluble salts in general, as well as for detecting soluble potassium potas-sium compounds in muds, clays and ashes, dissolve a portion of the sample sam-ple In a small quantity of water, allow al-low the undissolved material to settle set-tle out, remove a drop of the clear solution bv means of the loop of platinum wire and test it in the flame, as described for waters and brines. In tests for alum and other sulphates, the clear solution should be poured off from the Insoluble residue and some hydrochloric acid added before making the test. The water used in j all such testa should be examined to see whether it contains potassium. An organic substance to be tested is first ignited or burned at as low a temperature as possible until only the ash remains. The ash is then tested for potassium according to the procedure described for soluble salts. Test for Alunite. Alunite is tested by powdering the sample and moistening it with hydrochloric hydro-chloric acid. By means of the platinum loop, transfer a portion of the moistened powder to the flame, ignite ig-nite and observe the color of the flame through the Merwin color screen. If potassium is present the flame will appear a deep reddish violet. vio-let. This is a test for potassium and not for alunite, as other potash-bearing materials, especially leucite and glauconite, will give similar results with such treatment. W. T. Schaller gives the following follow-ing simple field test for the mineral alunite: Boil the powdered sample with water or with hydrochloric acid for several minutes; after allowing the powder to settle, pour off the liquid and repeat the operation to insure the removal of all soluble sulphates. Dry the powder and heat to dull red- ! ness. Again boil in water and, after , settling, pour off some of the clear liquid. To this add a small fragment or a solution of barium chloride. If the mineral is alunite. a heavy white precipitate will form. To be sure that the water used in this test does not contain sulphate in solution it should be tested with barium chloride and if it gives a marked precipitate It cannot can-not be used. For this test all tiiat is required that was not included in the equipment for the detection of potassium is a little barium chloride, j a small crucible In which to ignite the mineral and a support for the cruel- ! ble. ! In order to detect potassium in silicate rocks and minerals, such as feldspar, granite, leucite, rhyoiite, glauconite and sericite, powder the j material finely, mix with an equal amount of pure gypsum and moisten j the mixture wl;h dilute hydrochloric I acid. By means of the loop of platinum wire transfer a portion of the mixture to the flame. Ignite and ohserve the color through the Merwin Mer-win color screen. The reddish violet color will be apparent if potassium is present. |
