Zinc Recovery of Low Grade Concentrate from Vazante Mine …
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Fig. 2 Tests zinc yield
Fig. 3 Pictures of accretion formation inside the kiln during the tests
shows the evolution of accretion generation in the tests.
Regarding the quality of the slag, the tests indicated that the variation in the
percentage of LGCV in the feed affects mainly the Fe content. Therefore, as currently
the slag generated in the industrial process is applied as an iron source for cement
production and also for the production of sinter for steel mills, the percentage of
low grade concentrate in the industrial scale feed should be limited to 10%. Table 3
presents the slag quality of each test.
Conclusions and Recommendations
The low grade zinc concentrate from the Vazante mine is suitable for feeding the
Waelz kiln for the generation of zinc oxide. Zinc recovery was not reduced up to 40%
of the low concentrate in the feed blend. In addition, the accretion formation in the
furnace was reduced as the percentage of low feed concentrate increased, which is
very desirable as this phenomenon may lead to interruptions in the cleaning process.