Search results for " Pickling"
showing 6 items of 6 documents
Utilization of waste sodium sulfate from battery chemical production in neutral electrolytic pickling
2021
Several industrial activities produce metal sulfates, which are controlled by strict limitations for wastewater concentrations of sulfate. One emerging area where these activities occur is the production of lithium-ion battery chemicals in which sodium sulfates are formed because of cathode precursor co-precipitation. Several solutions for sulfate removal exist, but one option is to reuse the sulfate side stream in other processes to increase circular economy and atom efficiency. In this paper, the reuse of sodium sulfate solution in a steel industry pickling solution is considered. Neutral electrolytic pickling experiments were carried out to compare the pickling behavior of the electrolyt…
Economic Benefits of Waste Pickling Solution Valorization
2022
An integrated hybrid membrane process, composed of a diffusion dialysis (DD), a membrane distillation (MD) and a reactive precipitation unit (CSTR), is proposed as a promising solution for the valorization and onsite recycling of pickling waste streams. An economic analysis was performed aiming to demonstrate the feasibility of the developed process with a NPV of about EUR 40,000 and a DPBP of 4 years. The investment and operating costs, as well as the avoided costs and the benefits for the company operating the plant, were analyzed with an extensive cost tracking exercise and through face-to-face contact with manufacturers and sector leaders. A mathematical model was implemented using the …
Recovery of zinc from spent pickling solutions by liquid–liquid extraction using TBP
2019
In this paper, recovery of zinc from real spent pickling solutions by liquid–liquid extraction with tributyl phosphate (TBP) was studied. In particular, the effects of some parameters were investigated, such as the volume ratio between the organic phase and real spent pickling liquor (O/A) (1:2, 1:1, 2:1, 4:1), the stirring time (5–20–30 min) and the TBP concentration (10%–55%–100%), in order to determine the conditions leading to higher zinc extraction efficiency, as well as selectivity in relationships to other metals such as iron. After zinc extraction, TBP was successfully regenerated. Among several tested solutions, water allows zinc recovery higher than 90%, especially at 10% diluted …
Metals Recovery from Waste Pickling Solutions by Reactive Precipitation
2021
Pickling is one of the most important steps in steel manufacturing industry. During the process, an acid reacts with the surface oxides causing metal ions accumulation in the pickling solution. Disposal of the waste acid represents a critical issue for the hot-dip galvanizing industry in terms of environmental damage and high costs. Recovering of the main products by using an integrated process, with the perspective of a circular approach, could minimize the wastewater production, leading to reinvigorate this industrial sector economy. In this context, recovery of the metal ions mainly present in the pickling solution, such as Fe and Zn, becomes a critical issue. In this work, the reactive …
Experimental investigation on the efficiency of zinc(II) recovery from waste streams by TBP liquid-liquid extraction
2016
In many industrial processes the presence of zinc in the wastewater may represent an obstacle to its high efficient regeneration. This is the case of the treatment of spent pickling solutions aiming the recovery of hydrochloric acid via pyrohydrolysis techniques. Hydrochloric spent pickling solutions from steel processing contain relevant amount of metals such as iron (Fe) and zinc (Zn) that may significantly affect recovery of hydrochloric acid (HCl) through pyrohydrolysis. In fact, although Fe may be recovered as ferric oxide (Fe2O3) and does not have a substantial effect on pyrohydrolysis process, zinc chloride (ZnCl2) evaporating can occlude nozzles and stick to the pyrohydrolysis react…
Recovering of zinc(II) from spent pickling solutions by liquid-liquid extraction
2015
Hydrochloric acid can be successfully recovered from spent pickling liquors with high efficiencies via pyrohydrolysis techniques. In the pickling solution feed, other metallic ions are typically present besides iron (mainly Fe2+) such as zinc(II). In order to avoid undesirable effects, zinc(II) has to be removed, because zinc chloride evaporates and sticks to the reactor walls, as well as it contaminates iron oxides product1. Moreover, zinc recovery is economically affordable because it allows the marketing of some products such as ZnCl2 and ZnSO4. In the present work, liquid-liquid extraction process has been selected to recover zinc(II) from pickling liquors, using suitable extractant age…