Studying the Process Parameters of Gas-Cleaning Plants to Improve the Environmental Performance of Aluminum Smelters.

The optimal process parameters of a gas-cleaning plant used to achieve and exceed its design efficiency are presented. The optimization conditions for the process parameters are determined. A situation schematic of static pressure (vacuum) measured at the design process parameters of the gas-cleaning system in the circuit of gas flues and process units is presented. One of the main causes of unstable operation of "dry" gas-cleaning systems is the lack of data on optimal process parameters. Such situations include changes in the properties of supplied alumina, gas-distribution balance, emergency shutdowns of one or more cleaning modules, etc. The results of study and testing of optimal gas cleaning parameters at one of the Russian aluminum plants under various operating conditions of gas-cleaning systems to ensure stable environmental performance of aluminum production are discussed. The case of emergency shutdown of two or more gas-cleaning modules is additionally examined. The test results show that when two or more modules fail or are shut down, the cleaning efficiency is not achieved when removing gaseous fluorine. Therefore, in such situations, it is necessary to increase the amount of fed alumina to 7.5 t/h and to increase the recycle rate to 3. [ABSTRACT FROM AUTHOR]