Seafood waste to empower metal recovery

Invotec Group, a manufacturer of printed circuit boards (PCBs), has joined a project to develop the use of seafood industry waste to recover metals from its effluent stream.

The manufacturer, which has facilities in Telford and Tamworth, is working with the Technology Strategy Board (TSB) on the Sustainable Treatment of Waste Using Recycled Chitosans (STOWURC) project.

The two-year project is designed to develop the use of waste products from the seafood industry to recover metals from the effluent [an outflowing of water or gas from a natural body of water, or from a human-made structure]  generated in PCB and related manufacturing processes.

The UK’s seafood industry generates large volumes of shellfish waste, including the shells of crabs and other crustaceans.

According to Invotec, these shells are typically expensive to dispose of, but are also a source of materials known as chitosans which are known to have the capacity to absorb metals.

A key aspect of the project will be to change the crab shells into useable materials and this will involve their mechanical and chemical conversion into a product with optimised 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, it will be desorbed into a solution from which it can be recovered as a metal by electroplating.

The overall aim is to use the materials produced from the crab shells in a similar manner to ion exchange resins, so that once the metal has been desorbed, the chitosan materials can be reused.

Again, the influence of absorption, desorption and plating conditions will be studied in order to optimise the overall process efficiency.

Ultimately, the project partners are aiming to develop regenerable chitosan-based materials and to define accompanying processes for a range of metals. The project consortium represents the whole requisite supply chain, from a supplier of crab shells to an end-user PCB fabricator.

The partners involved in the project include: 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 UK PCB industry and it will deliver details of the project and progress to its members via presentations at its evening seminars and through articles in the Institute’s journal.

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

Invotec Group managing director Tim Tatton said: “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.”

Liz Gyekye


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