Rotary kilns, operation basics

Chapter 2 Basic Description of Rotary Kiln Operation... 

The direct American process is basically a metallurgical operation. Ziac oxide ores are reduced usiag coal (qv) ia a rotary kiln at temperatures of 1000—1200°C to 2iac metal. At these temperatures the produced 2iac metal evaporates and is oxidi2ed with air to ZnO ia the upper part of the kiln. 

The carbonate (dolomite) is converted to the oxide (doloma) and sintered to the required density in either a rotary kiln or a shaft kiln operating at 1850°C or greater. There are basically two different production routes ... 

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