Crab Shells help to Recycle Circuit Boards

A Printed Circuit Board (PCB) manufacturer has joined a project to develop a use for waste products from the seafood industry in the recycling metals from the effluent generated in PCB and related manufacturing processes.

The Sustainable Treatment of Waste Using Recycled Chitosans (STOWURC) project has been set up under the auspices of the Technology Strategy Board – a Department for Business, Innovation and Skills (BIS) backed agency set up to drive innovation.

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

How it works

The company said that a key initial aspect of the two year project will be to change the crab shells into useable materials and this will involve their mechanical and chemical conversion into a granular form 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 was said to be the use 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.

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

Ultimately, the project partners said that they are aiming to develop ‘regenerable’ chitosan-based materials and to define accompanying processes for a range of metals.

In addition to their own desire to develop and exploit the new technology, the STOWURC project partners said that they have also identified international interest in using chitosan-based materials from PCB manufacturers, and there that there are also potentially much larger applications in other sectors, including surface engineering and metal finishing.

The project consortium represents the whole requisite supply chain, from a supplier of crab shells to 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.

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