Results of the test work that was conducted on the Gas Treatment Center installed at the Rio Tinto AP60 Technology Center located in Canada on the GTC which was originally supplied with standard filter bags except for one filtration module equipped with extended surface filter bags. Back in 2017, the original bags were approaching the end of their useful life and the test work was launched to acquire a deep understanding about control of process parameters to optimize the GTC performances if ESB filters would be installed in all filtration modules.