Abstract

A method for concentrating metal chlorides in and separating same from an iron(III) chloride-containing hydrochloric acid solution is described, wherein iron is precipitated from the solution as iron oxide, preferably haematite and filtered off in a filtration device, and the now further concentrated non-hydrolysable metal chlorides are removed from at least a part of the hydrochloric acid filtrate.

IPC Classes  ?

• C01G 49/06 - Ferric oxide [Fe2O3]
• C23G 1/36 - Regeneration of waste pickling liquors
• C01G 53/09 - ChloridesOxychlorides
• C01B 9/02 - Chlorides
• C22B 3/10 - Hydrochloric acid
• C22B 3/44 - Treatment or purification of solutions, e.g. obtained by leaching by chemical processes

Abstract

The invention relates to a method and device for producing an iron(III) chloride solution having an iron(III) chloride concentration of 30 wt% to 55 wt%, preferably 35 wt% - 50 wt%, by oxidizing a starting solution of hydrochloric acid containing iron and having an iron(II) chloride concentration of 10 wt% - 30 wt%, preferably 15 wt% - 25 wt%, comprising at least one oxidation step and two concentration steps, in which concentration steps water is evaporated from the solution of hydrochloric acid containing iron by supplying thermal energy, wherein the concentration steps are performed at different pressures, wherein the condensation energy of the resulting vapor is fed from the concentration step performed at higher pressure to the evaporator of the concentration step performed at lower pressure.

IPC Classes  ?

• C01G 49/10 - Halides