Tin use in float glass production totalled some 3,900 tonnes in China and 7,100 tonnes worldwide in 2016, according to estimates by Hou Yinglan from the Zhangzhou Kibing Glass company, who presented at ITRI’s Asia Tin Week in Kunming.
Tin is used in the production of float glass in a liquid “tin bath” to provide a flat surface over which molten glass can float and solidify. Hou Yinglan estimates that there were 359 float glass production lines in China in 2017, of which 129 are currently inactive. With each 600tpd float glass line requiring approximately 200 tonnes of tin, the total inventory of tin present in Chinese float glass plants is estimated to total some 71,800 tonnes.
Hou believes tin demand for construction of new lines weakened from 5,200 tonnes globally in 2014 to some 3,900 tonnes in 2016. This is due to a decline in new capacity being brought online annually, primarily as a result of overcapacity in China. However, due to the overall increase in global glass production capacity from 81.3 to 85.1 million tonnes of glass per year over the same period, Hou estimates that tin consumption as a result of losses during the production process has increased from an estimated 3,100 tonnes to 3,200 tonnes. Hou’s presentation also outlined the use of tin in chemical glass coatings, although this amounted to just 300 tonnes of annual refined tin use inside China.
ITRI View: Float glass production represents the sixth largest use for refined tin globally. Despite the recent trends outlined, the tin used annually is marginally higher than a decade ago, increasing from an ITRI estimate of 6,700 tonnes in 2006 to Hou’s estimate of 7,100 tonnes in 2016. The ongoing expansion of glass production capacity will be required simply to maintain current levels of tin demand. As such we do not believe any significant growth in tin use in this application to be likely.