Dynamic Simulation For Engineering Clients

Core Resources offers dynamic simulation as an additional service for engineering clients. Dynamic simulation of a flowsheet or critical unit operation can mean the difference between guessing at and understanding important transient behaviour. Our dynamic simulation consultation service package delivers process flow diagrams, time-series mass and energy balances, process models and a professional report detailing results and recommendations. Core uses and recommends ITHACA® dynamic chemical process simulator software.

Why dynamic simulation?

Dynamic simulation can be the key to running and maintaining an efficient and safe operational process plant. The only steady-state process is on the drawing board. Processes that experience significant non-steady state periods – repeated input step changes, shutdown-restart cycles, batch process cycles, weather impingement – are at risk of running sub-optimally and even uneconomically unless these transient periods are well understood and planned for. Dynamic simulation empowers Core’s clients with the ability to review current plant operations as they are actually experienced, simulate multiple alternative scenarios, and make data-driven changes.

Some aspects of a process design should always be tested dynamically either before or as part of detailed design. For example, Core routinely simulates pilot plants in order to check batch cycle interactions and time to steady-state. Dynamic simulation of full-scale heap leach operations can also provide insights into true heap recovery ramp-up times and provides a means of improving project economics by optimising lift schedules and planning for the impact of weather cycles. Dynamic simulation is also crucial for testing and optimising surge capacity, offline tuning of control loops, and testing of hazardous equipment start-up and shut-down procedures.

Examples of dynamic simulation

Mine water treatment

A mine with legacy environmental issues requested dynamic simulation to better understand the impacts on pit water level of rainfall, forced evaporation, natural evaporation and tailings deposition; to provide an estimate of the size of paste plant required to direct excess tailings to underground; and to provide an estimate of soluble copper loss from pit water as a result of the deposition of alkaline tailings.

Five-year simulations determined that up to six evaporators would be required to control pit water level; approximately 24% of soluble copper would be lost; and a 312 ktpa paste plant was required.

Pilot plant simulation

Dynamic simulation of the Toowong Process pilot plant was undertaken to determine time to steady-state, assess interactions of batch process equipment, and assess the impact of sampling on leach kinetics.

Simulation results indicated that: approximately 400 hours of operation were required before the process was at steady-state on any new feed-stock; the PLS tank required a minimum active volume of 20 L in order to allow for both a short- and long-term oscillation in level; and the effect of sampling was negligible.