Hydrogen Reduction of Ferric Ions for Use in Copper Electrowinning

PDF Version Also Available for Download.

Description

The conventional copper electrowinning process uses the water hydrolysis reaction as the anodic source of electrons. However this reaction generates acid mist and requires large quantities of energy. In order to improve energy efficiency and avoid acid mist, an alternative anodic reaction of ferrous ion oxidation has been proposed. This reaction does not involve evolution of acid mist and can be carried out at a lower cell voltage than the conventional process. However, because ferrous ions are converted to ferric ions at the anode in this process, there is a need for reduction of ferric ions to ferrous ions to ... continued below

Creation Information

Noah, Karl S.; Bruhn, Debby F.; Wey, John E. & Cherry, Robert S. January 1, 2005.

Context

This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. It has been viewed 21 times . More information about this report can be viewed below.

Who

People and organizations associated with either the creation of this report or its content.

Sponsor

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this report. Follow the links below to find similar items on the Digital Library.

Description

The conventional copper electrowinning process uses the water hydrolysis reaction as the anodic source of electrons. However this reaction generates acid mist and requires large quantities of energy. In order to improve energy efficiency and avoid acid mist, an alternative anodic reaction of ferrous ion oxidation has been proposed. This reaction does not involve evolution of acid mist and can be carried out at a lower cell voltage than the conventional process. However, because ferrous ions are converted to ferric ions at the anode in this process, there is a need for reduction of ferric ions to ferrous ions to continue this process. The most promising method for this reduction is the use of hydrogen gas since the resulting byproduct acid can be used elsewhere in the process and, unlike other reductants, hydrogen does not introduce other species that need subsequent removal. Because the hydrogen reduction technology has undergone only preliminary lab scale testing, additional research is needed to evaluate its commercial potential. Two issues for this research are the potentially low mass transfer rate of hydrogen into the electrolyte stream because of its low solubility in water, and whether other gaseous reductants less expensive than hydrogen, such as natural gas or syngas, might work. In this study various reductants were investigated to carry out the reduction of ferric ions to ferrous ions using a simulated electrolyte solution recycled through a trickle bed reactor packed with catalyst. The gases tested as reductants were hydrogen, methane, carbon monoxide, and a 50/50 mixture of H2 and CO. Nitrogen was also tested as an inert control. These gases were tested because they are constituents in either natural gas or syngas. The catalysts tested were palladium and platinum. Two gas flow rates and five electrolyte flow rates were tested. Pure hydrogen was an effective reductant of ferric ion. The rates were similar with both palladium and platinum. The ferric iron reduction increased with both the flow rate of gas as well as the liquid flow rate (up to ~0.1 g/L/min). Pure carbon monoxide also reduced the ferric ion, but at a rate about one tenth that of pure hydrogen at similar conditions. The syngas mixture of equimolar hydrogen and carbon monoxide reacted at a rate intermediate between each gas as a pure stream (up to ~ 0.06 g/L/min). This gas mixture shows that some form of unpurified reformer gas could be used to reduce the ferric ion in the electrolyte solution. Nitrogen was inert causing very little to no reduction of ferric ion.

Language

Item Type

Identifier

Unique identifying numbers for this report in the Digital Library or other systems.

  • Report No.: INEEL/EXT-05-02602
  • Grant Number: DE-AC07-99ID-13727
  • DOI: 10.2172/911606 | External Link
  • Office of Scientific & Technical Information Report Number: 911606
  • Archival Resource Key: ark:/67531/metadc887877

Collections

This report is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this report?

When

Dates and time periods associated with this report.

Creation Date

  • January 1, 2005

Added to The UNT Digital Library

  • Sept. 22, 2016, 2:13 a.m.

Description Last Updated

  • Oct. 19, 2016, 2:02 p.m.

Usage Statistics

When was this report last used?

Yesterday: 0
Past 30 days: 3
Total Uses: 21

Interact With This Report

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

Noah, Karl S.; Bruhn, Debby F.; Wey, John E. & Cherry, Robert S. Hydrogen Reduction of Ferric Ions for Use in Copper Electrowinning, report, January 1, 2005; [Idaho Falls, Idaho]. (digital.library.unt.edu/ark:/67531/metadc887877/: accessed October 22, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.