Around 1.5 million tonnes of container glass were recycled in the UK in the past twelve months to June 2008, 200,000 tonnes more than a year earlier. However, although there was an increase in the amount of cullet going into remelt applications – including domestic container manufacture, glass wool and export – the majority of the increase was absorbed by the aggregates market. Moreover, the amount of cullet used by the UK container manufacturing industry remains substantially below the peak reached in 2006. In 2007, and for the first time, less than half of the container glass recovered for recycling was used in domestic container remelt. Glass industry sources indicate that this reflects a shortage of high quality colour-separated cullet, which they attribute to increases in both mixed-colour and co-mingled glass collections.
The combination of increasing production and falling cullet use has led to a fall in the recycled content of UK-produced glass containers, from 36 per cent in 2005 to around 30 per cent in 2007 (Graph 2). The most significant decline has been in green furnaces, which are currently operating with a cullet content of less than 70 per cent, compared with around 85 per cent in 2005. This is significantly lower than the technical limit, which suggests that the so-called ‘green glass mountain’ may have disappeared, a stark contrast to the story of recent years.
In addition, it is estimated that around 80,000 tonnes of flat glass was used in domestic container glass furnaces in 2007. Industry contacts have indicated that they are using more flat cullet, in part owing to shortages of clear container cullet, although there are technical limitations due to differing glass chemistries. Exports of cullet for overseas container manufacture rose by over 40,000 tonnes in the year to June 2008. Although this increase – against a background of declining UK usage – seems surprising, it reflects two key factors
