E/MJ : engineering and mining journal . esent, but no sulphuric compounds;whereas at moderate temperature, sulphurous and sul-phuric compounds may be present. Sulphur trioxideis unstable at high temperatures (at atmospheric pres-sure it is practically dissociated at 1,000 deg.), and thetemperature range in which it forms rapidly by com-bination of sulphur dioxide and oxygen is stable andnarrow (approximately 250 to 600 deg. C. under at- October 18, 1919 Engineering and Mining Journal 643 mospheric pressure). If free oxygen and sulphur orsulphur dioxide are present in igneous emanations, itwoul
E/MJ : engineering and mining journal . esent, but no sulphuric compounds;whereas at moderate temperature, sulphurous and sul-phuric compounds may be present. Sulphur trioxideis unstable at high temperatures (at atmospheric pres-sure it is practically dissociated at 1,000 deg.), and thetemperature range in which it forms rapidly by com-bination of sulphur dioxide and oxygen is stable andnarrow (approximately 250 to 600 deg. C. under at- October 18, 1919 Engineering and Mining Journal 643 mospheric pressure). If free oxygen and sulphur orsulphur dioxide are present in igneous emanations, itwould be expected that, in cooling, sulphur trioxidewould form and that at suitable tempei-ature the sul-phates would also form. Sulphuric acid can also be formed readily by the re-duction of ferric solutions and sulphur dioxide. Ifemanations contain no free oxygen, that element may,Combined with the metals or with hydrogen at high tem-perature, together with sulphur, form the oxides ofsulphur and sulphuric compounds at lower HEAD OF LITTLE COTTONWOOD CANYON ALTA RANGE That this reduction of metallic oxide and oxidation ofsulphur compounds can take place is indicated not onlyby experimental data but by the abundance of ferriccompounds in igneous rocks and mineral depositsformed at high temperature, though those ferric are not only commonly absent in veins formedat moderate temperature, but in the adjacent wallrocks have been largely reduced. In contrast to this,sulphuric compounds are only sparsely represented inigneous rocks and mineral deposits formed at high tem-perature, but are frequently abundant in depositsformed at intermediate and low temperatures, and inmany deposits are associated with abundant ferrousand manganous compounds. Such changes may be ob-served in a single deposit that has continued to formover a wide range of temperature, as that of the Cactusmine of the San Francisco district. The alunite veins at Marysvale appear
Size: 1782px × 1402px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bo, bookcentury1900, bookdecade1910, booksubjectmineralindustries
