Crab shells tapped for metals recovery

Invotec Group, a maker of printed circuit boards (PCB) based in the U.K., has announced its participation in the Sustainable Treatment of Waste Using Recycled Chitosans (STOWURC) project, set up under the auspices of the U.K.’s Technology Strategy Board.

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Still in early stages, the two-year-long project is designed to develop the use of waste products from the seafood industry to recover metals such as copper from the effluent generated in PCB and related manufacturing processes. The U.K. seafood industry generates large volumes of shellfish waste, including shells from crabs and other crustaceans. The shells can be expensive to dispose of but are also a source of chitosans, materials known to have the capacity to absorb metals.

Initially the project will focus on mechanically and chemically processing the shells into a granular form with optimized absorption capabilities. The materials will then be evaluated over a range of operating conditions to determine how well they can absorb copper. Once saturated with copper, the material will be desorbed into a solution from which the metal can be recovered via electroplating.

According to an Invotec press release, the project partners hope to develop reusable, regenerable chitosan-based materials and to define processes for a range of metals.

The project consortium represents the supply chain and includes a supplier of crab shells and an end user PCB fabricator. Specifically the partners are Kynance Cornish Crab, Chestech, Env-Aqua Solutions, C-Tech Innovation, Invotec, the Surface Engineering Association and the Institute of Circuit Technology. The ICT is the dissemination partner for the U.K. PCB industry and it will deliver details of the project and progress to its members via presentations and through the Institute’s journal.

The STOWURC project partners have also identified international interest in using chitosan-based materials from PCB manufacturers for other applications, including surface engineering and metal finishing.

Says Tim Tatton, Group Managing Director of Invotec, “We have a strong commitment to meeting our environmental responsibilities, so we were delighted to have the opportunity to participate in a project which promises to offer not only environmental but also commercial benefits.”