Show volatilization OF ZINC ORES behavior of zinc ores treated by the volatilization process depends largely on the arrangement of the mineral in the ore also on oil the atmosphere that is maintained in the furnace during treatment experiments made by metallurgists of the interior department at the salt lake city experiment station of the bureau of mines have indicated that in a strictly oxidizing atmosphere little zinc is iced especially in the zinc carbonate ores of the good springs nev districts the tests of the yellow pine mining companas Comp anys ores and of other ores from the goodsprings Good springs district were made on zinc concentrates in which tile the zinc content ranged from 30 to 40 per cent the silver and lead ife i fe content varying from 4 to 8 ounces and from 4 to 8 per cent respectively the quality of silver and lead volatilized ranged from about 50 to 80 per cent whereas the total amount of zinc volatilized generally averaged less than 1 per cent analysis of the fume precipitated in volatilization tests on these ores indicated high essays in silver and lead and 3 to 6 per cent in the zinc assay the behavior of zinc is very erratic the conditions under which it is volatilized probably de depending largely on the sulphur content in the ore the presence of sulphur causes a complicated series of chemical reactions during the usual treatment consequently a variable quantity of the zinc is driven off with other volatile materials when crude ores high in sulphur content have been treated most experiments indicated nearly complete volatilization of the zinc but when the ore was given a preliminary roast to reduce the sulphur content the amount of zinc varied considerably the presence of zinc in carbonate ores containing silver lead and zinc indicates that by volatilization a clean cut separation can be made between the lead and zinc on the other hand in treating complex sulphide ores much of the zinc was volatilized in nearly every experiment and was subsequently precipitated in the cottrell as chloride with the other metal chlorides details of these experiments are given in bulletin the chloride volatilization process of ore treatment which may be obtained from the department of the interior bureau of mines washington D C |