Project Synopsis

Process engineering assistance for a sulfur dioxide wet caustic scrubber upgrade at a smelting battery within a copper refining facility.

Project Summary


Process Engineering Associates, LLC (PROCESS) was subcontracted by an engineering consulting firm to provide process engineering assistance for an acid gas (sulfur dioxide) cleaning system (wet caustic scrubber) upgrade for a smelting battery at a copper refining facility.  Specifically, PROCESS prepared a process flow diagram (PFD) for the gas cleaning system that reflected changes that had been made to the facility since the initial gas cleaning system had been installed as well as changes that reflected operation after the system upgrade was completed.  The following project tasks were executed:

  • Initial site visit to the copper mining facility for the purpose of gathering engineering and operations data on the gas cleaning system and for interviewing engineering and operations personnel relative to system operation
  • Development of a process design basis that detailed the basic operating parameters associated with current and future system operation
  • Development of computer process simulations of the system (average design case and maximum design case) using licensed commercial process simulation software
  • Preparation of a process flow diagram (PFD) depicting future system unit operations and detailed mass and energy balance information for system operation.

The primary change to the system since its original installation involved the change from soda ash to magnesium hydroxide as the neutralizing medium.  The future change to the system involved the addition of a wet electrostatic precipitator (WESP) downstream of the scrubber to collect particulate from the offgas.  The process simulations for this system were especially challenging due to the complicated nature of magnesium hydroxide neutralization chemistry, specifically with regard to the chemical equilibrium relationships between the neutralization products.

The process flow diagram information was used as the basis for the selection of the WESP and detail design of the system upgrade.

Industry Type

  • Minerals & Metals Refining

Utilized Skills

  • On-site data collection
  • Process flow diagram (PFD) preparation
  • Computer process simulation
  • Magnesium hydroxide equilibrium chemistry