Recovery of Nickel and Iron From a Waste Stream and Evaluation of Electrochemical Methods for Cleaner Production
There are two aspects to this project which is being carried out by Envirotech Limited at the GE Superabrasives Ireland industrial diamond manufacturing site: Nickel and iron recovery from a waste stream; Evaluation of electrochemical methods for cleaner production and Nickel and Iron Recovery from a Waste Stream An acidic waste stream containing nickel and iron is currently produced at a volume of 25 m3 per week. The stream contains 10% iron and 4% nickel. The current treatment involves pH correction to precipitate both as a sludge. The sludge is then dried and sent to France for recovery. The project aims to develop a process to separate the iron and nickel in such a manner as to yield a nickel precipitate and an iron solution. The nickel would be recovered as a high value material and reused in the nickel plating industry. The remaining iron solution would be pure enough to be reused in the wastewater treatment industry. The main environmental benefit would be in reducing and hopefully eliminating what is currently a waste which needs to be transported to France for further treatment or alternative landfilled as a sludge. It is envisaged that there would be more long term economic benefit also by providing an economical method of recycling the two metals by processing them into a form valuable to specific markets. The value of these materials is likely to remain steady in reusable forms whereas the costs of disposal are likely to increase. Evaluation of Electrochemical Methods for Cleaner Production Industrial diamond manufacture involves separation of the diamond from catalyst matrix. Replacing 80% of the chemicals used in one step of this process would significantly reduce both effluent concentration and quantities of nitrates produced. It is proposed to use electrochemical technology to achieve the dissolution of metal components in the step known as YC or yield checking. If successful it is envisaged that this process would be transferred to the plant-scale process. Although still very much at a research stage it is hoped that this element of the project would result in a significant reduction in the amount of chemicals used. Estimates are nitric acid usage reduction by 155 tonne / yr lime usage reduction by 75 tonne / yr.
If you want to read more about this project, you can do so at erc.epa.ie.
Environmental Protection Agency 2001-CP-40
Keywords: Metal; Industry; Waste Recovery; Treatment