HSC Simulation of Hydrometallurgical Processes Petteri Halli Taina Kalliomäki CHEM-E6810 Chemical precipitation  

Chemical precipitation Precipitating can be used recovering metals from liquids like waste waters as sulphides, hydroxides or carbonates Metal sulphides are more stabile Hydroxides can dissolve into the solution after precipitating, less stabile Carbonates dissolve in liquid solutions better selectivity In this simulation Cu is precipitated from leached and filtered electronic scrap solution as copper carbonate using CaCO3 and other metals metal as sulphides using H2S(g) 31.12.2018

Objective Separate impurities and Cu from the leached and filtered electronic scrap before EW Precipitate Cu as carbonate and dissolve it into H2SO4 for EW process Precipitation of impurities using H2S (g) Chemical precipitation is a part of solution purification of leached and filtered electronic scrap 31.12.2018

HSC-SIM Chemical precipitation

Input process parameters Reactor 1: Cu precipitation Feed H2O 2.95 t/h Cu+2 0.60 t/h Zn+2 0.01 t/h Fe+2 0.13 t/h Ni+2 0.05 t/h Ca+2 needs to be controlled! CO3-2 needs to be controlled! CaCO3 needs to be controlled! Reactor 2: CuCO3 dissolution H2SO4 needs to be controlled! H2O needs to be controlled! CuCO3 Reactor 3: Precipitating other metals H2S (g) needs to be controlled! Impurities 31.12.2018

Draw units and streams 31.12.2018

Select unit models Save the process and save backup 31.12.2018

Create variable list 31.12.2018

Add reactions 31.12.2018

Specify distributions 31.12.2018

Controls Some feeds has to be controlled Adjusting the concentrations of the feeds Avoid using insufficient amounts of reagents Avoid using excess amounts of reagents and waste the chemicals 31.12.2018

Create controls Controlled inputs and outputs Reactor 1 Reactor 2 Input: CaCO3 and H2SO4 Reactor 2 Input: H2SO4 and H2O Output: H2SO4 and Cu Targets: 100-150 g/L H2SO4 and 20-30 g/L Cu Reactor 3 Input: H2S 31.12.2018

Create controls Reactor 1 Reactor 2 Reactor 3 Custom sheet 31.12.2018

Run the process model Run the process model If everything in Log viewer is green there is no errors 31.12.2018