Plant to turn contaminated soils to glass earmarked for Midlands

A 40 acre brownfield site near Sheffield is being considered as the home for the UK's first commercial vitrification plant to turn contaminated soils and other wastes into glass.

The £86 million plant is being planned by Vitrium Holdings Ltd which claims it will create at least 300 jobs in the area.

Vitrium have already held talks with local authority and development agency representatives about the plans and briefings have been sent to Tony Blair, John Prescott, and Sheffirld MPs David Blunkett and Richard Cabon.

If successful the plant could provide an excellent solution to the problem of contaminated soils and wastes. It proposes to eliminate contamination completely and produce an environmentally safe glass product to be made into building aggregate, cement and even tiles and kitchen surfaces.

Vitrium Chief Executive John Evans said: “Our process is cleaner, safer and less wasteful than treating wastes with chemicals or burying it in large concrete blocks. The key point is that the contamination is dissolved in the glass and therefore cannot leak out.”

“The waste material which will be mainly contaminated soil and industrial process waste will be brought to the plant in special containers loaded onto predominantly trains but some will arrive in canal boats and by road. At the plant the waste will be treated in a negatively pressured environment to ensure the elimination of emissions of any noise or odour,” he added.

Vitrification is the process by which a material is converted into glass. Vitrification is achieved by cooling a material from its liquid state to a solid state so that no crystals form within the solid. The material is then said to have been vitrified.

Apart from using the basic constituents of a glass, usually silica, limestone and soda ash, the glass industry has always used modifying agents to help improve some desired quality in the final product. These modifying agents are predominantly heavy metals added to the glass. Alone these modifying agents are potentially toxic materials, but dissolved into the glass and part of the glass structural matrix they are harmless and improve the quality of the glass.

Vitrium has made use of conventional glass technology to develop a method of waste treatment that will chemically bind heavy metals, and other constituents of waste, into a stable compound which can be re-used and is environmentally sound. This is due to the molten glass acting as a solvent so heavy metals dissolve into the molten glass and upon cooling become part of the chemical matrix. Also, because of the high temperatures involved in the glass making process the carbon based compounds contained within the waste are destroyed by pyrolysis and combustion. The process therefore fully destroys the waste materials that are treated.

Theoretically a wide range of materials could be treated but this proposal aims to limit itself to contaminated soils, filter dust, foundry sand, oil refinery residues, spent activated carbon and spent catalysts.

Vitrium says reaction to the proposals has been positive from local authorities and development agencies in the region, where centuries of intense industrial activity have left a legacy of millions of tonnes of contaminated soil. It is expected that much of its initial business will come from the local area, while the business can also draw on the area’s glass making heritage.

Phil Roberts, Chief Executive for Sheffield First for Investment, said: “The sheer scale of the investment, plus the new job implications, makes it a very exciting prospect.”

“The development of new environmental technologies and processes is a key aspiration for the Regional Economic Strategy. This project is particularly interesting because it turns an existing liability – contaminated land – into a productive asset.”

By David Hopkins

Action inspires action. Stay ahead of the curve with sustainability and energy newsletters from edie