Precious Metals Recovery LLC RCRA Permit Application Dry Hills ...

Above the retort tray/drum transfer station in the event this feature is implemented in
the future (Note: it is expected that drums can be retorted directly to minimize
material transfer, but a provision has been made in the layout and sizing of the
hygiene exhaust system for the transfer station).
Above the Mercury Flask Transfer Station.
The design volume of the filter press hoods is to continuously provide a minimum of three air
changes per hour for the process area. The retort dome hood will be operational intermittently,
only when the operations take place (e.g., when retort domes are open for loading and
unloading).
All exhaust flow is generated by the ventilation fan, which also creates negative pressure in the
other plant spaces of the proposed TSF. There are two ventilation fans (one operating and one
stand-by) to provide continuous ventilation and redundancy.
During shift hours, hygiene gas will pass through a dust collector to remove any dust prior to
entering a HEPA filter for further polishing and a carbon filter for mercury removal. Dust from
the dust collector is transferred to a drum via a rotary valve (see Figure 1.2-7 below). The
captured dust is treated in the retort to recover mercury (see Appendix 1-C Process Flow
Diagrams).
PMR RCRA Permit Application, Dry Hills Facility Page 29
JBR Environmental Consultants, Inc. | HATCH March 2013