Chromium Concentrate Recovery From Solid Tannery Waste in a Thermal Process

Area of Science:

• Environmental Science
• Chemical Engineering
• Materials Science

Background:

• Leather processing generates substantial solid waste containing chromium (Cr).
• Current waste management practices pose environmental challenges.
• Solid tannery waste requires effective treatment and valorization strategies.

Purpose of the Study:

• To review solid tannery waste treatment technologies.
• To evaluate the efficacy of waste incineration in a tunnel incinerator.
• To assess the potential for chromium recovery and reuse from tannery waste.

Main Methods:

• Review of existing solid tannery waste treatment technologies.
• Experimental incineration of three types of solid tannery waste (trimmings, shavings, buffing dust) in a tunnel incinerator.
• Chemical and physical analyses of the resulting ash (elemental analysis, ICP-OES, XRD).

Main Results:

• Incineration is applicable to all tested types of solid tannery waste.
• The process allows for heat recovery and concentration of chromium in residues.
• Residual ash contained up to 53.1% (w/w) Cr as Cr(III) oxide with minimal organic content.

Conclusions:

• Incineration is a viable technology for treating solid tannery waste.
• The process enables the recovery of chromium, potentially as a Cr ore substitute.
• This approach offers a sustainable solution for managing tannery byproducts and recovering valuable resources.