TY - GEN
T1 - Optimization of iron and chromium recovery from mixed-acid pickling liquors
AU - Dufour, Javier
AU - Gálvez, José L.
AU - Negro, Carlos
AU - Löpez-Mateos, Federico
PY - 2005
Y1 - 2005
N2 - Spent pickling liquor is a very corrosive waste from stainless steel treatment. It is mainly composed of iron (30 - 40 g/l), chromium (8-10 g/l), nickel (3-6 g/l) and hydrofluoric (40 - 60 g/l) and nitric (100-120 g/l) acids. Only 5% of chromium and iron content B in the metallic ion form (Fe3+ or Cr3+), while the 95% of these metals are forming several complexes like MeFn(3-n)+. This situation implies complicated treatment processes without metals recovery or high operating and maintenance costs. A modified precipitation process has been developed where iron and chromium precipitate as alkaline fluorides while nickel remains in solution and could be recovered as hydroxide in a further stage. The collected fluorides are then hydrolysed to obtain the corresponding rretal hydroxides and a soluble fluoride salt. This paper summarizes the optimisation of modified precipitation by means of an experimental design where operating variables of the process have been considered.
AB - Spent pickling liquor is a very corrosive waste from stainless steel treatment. It is mainly composed of iron (30 - 40 g/l), chromium (8-10 g/l), nickel (3-6 g/l) and hydrofluoric (40 - 60 g/l) and nitric (100-120 g/l) acids. Only 5% of chromium and iron content B in the metallic ion form (Fe3+ or Cr3+), while the 95% of these metals are forming several complexes like MeFn(3-n)+. This situation implies complicated treatment processes without metals recovery or high operating and maintenance costs. A modified precipitation process has been developed where iron and chromium precipitate as alkaline fluorides while nickel remains in solution and could be recovered as hydroxide in a further stage. The collected fluorides are then hydrolysed to obtain the corresponding rretal hydroxides and a soluble fluoride salt. This paper summarizes the optimisation of modified precipitation by means of an experimental design where operating variables of the process have been considered.
UR - https://www.scopus.com/pages/publications/32044452450
M3 - Conference contribution
AN - SCOPUS:32044452450
SN - 8495520044
T3 - REWAS'04 - Global Symposium on Recycling, Waste Treatment and Clean Technology
SP - 361
EP - 370
BT - REWAS'04 - Global Symposium on Recycling, Waste Treatment and Clean Technology - Proceedings
A2 - Gaballah, I.
A2 - Mishra, B.
A2 - Solozabal, R.
A2 - Tanaka, M.
T2 - REWAS'04 - Global Symposium on Recycling, Waste Treatment and Clean Technology
Y2 - 26 September 2004 through 29 September 2004
ER -
