"The present work is a continuation of the previous investigations of Gross and Warrington and Liu in which the effect of various reducing agents on the vacuum reduction of zinc sulfide was studied. The author became interested in this topic while reading the papers by these investigators in which they recommended that further work be performed in an attempt to prevent zinc sulfide from distilling over during reduction, thereby contaminating the zinc condensate. The original plan was to perform a few runs for the purpose of duplicating the results that were reported by Liu, and from this point carry on the work using reducing agents other than iron. Soon after the work had been started, it was found that the results of Liu for the reduction of zinc sulfide could not be duplicated, particularly at the lower reaction temperatures; therefore, the previously reported results were cast aside and a considerable amount of work was performed for two purposes: (1) to determine the reasons for the lack of agreement, and (2) to investigate thoroughly several of the operational variables in order that this work might be given more justification for being acceptable than the previous work by Liu. In addition to using several other reducing agents at various reaction temperatures and for specified times at temperature, experiments were made to determine the effect, if any, of the crucible shape and the degree of charge compaction on the recovery of metallic zinc.
The latter phase of the work was concerned with an attempt to improve the zinc condensates that were produced in previous iron reduction runs by redistilling a carefully selected composite charge for various times at certain temperatures. It shall be seen that certain reducing agents were very effective in reducing zinc sulfide directly to metallic zinc; however, a portion of the sulfur in the charge also distilled into the condensing region as zinc sulfide. Moreover, the majority of the condensates that were produced were extracted either as a loose powder or as thin brittle sheets. Sometimes a suitable metallic sheet was produced, but only if a high reaction temperature was used. Therefore, the purpose for redistilling the condensates as a composite charge was twofold: (1) to improve the physical characteristics of the condensates by attempting to produce zinc as strong metallic sheets, and (2) to determine the extent of evaporation of sulfur as zinc sulfide from the composite and its effect on the purity of the resulting condensate "--Introduction, pages 2-4.
Schlechten, A. W.
Materials Science and Engineering
M.S. in Metallurgical Engineering
Missouri School of Mines and Metallurgy
vi, 83 pages
© 1952 Merritt E. Langston, All rights reserved.
Thesis - Open Access
Zinc sulfide -- Metallurgy
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Langston, Merritt E., "Direct reduction of zinc sulfide under vacuum" (1952). Masters Theses. 2054.