The Pioneer
Reethah Desai
The story of the zinc smelting process.
Transcript
I first worked in Bristol in 1975. I was about to go on an ocean mining project and I had to visit the team at Imperial Smelting Processes. I rode on Brunel’s Great Railway to Temple Meads.
At Avonmouth I met Dr Woods, one of the founders of the zinc smelter. I noticed one particular thing that this distinguished Fellow of the Royal Society said: “The only metal that can be won from the ocean is magnesium.”
Away for three years, unsuccessfully trying to recover other metals I often though of these words. On return, I read up his zinc process. It was my introduction to the fascinating science of extractive metallurgy.
Pre-war methods of extracting zinc were highly inefficient. A continuous blast furnace would have much better prospects, but how to recover zinc from furnace gas which was a horrific mixture of solid particles and poisonous gasses. I marvelled at the solution: quench it with a shower of molten lead. What a leap of inventive thinking that was. Cool the lead, and zinc would form a top layer and could be poured off. The Imperial Smelting Furnace was born.
Others tackled the thermodynamics and the invention of practical solutions. The first commercial plant was built at Avonmouth in 1964 and the process was sold to twelve countries around the world.
In 1983 my company moved to Bristol. Reading had helped me stay in touch, and on the process team, I helped the basic design of the last smelter, constructed in India.
Many different ways of improving the Avonmouth plant were studied. At the end, I was involved myself. Dramatic advances were offered, but were not pursued.
The fickle finger of fate was pointed; they saw no future in the smelter and shut it down. Today it is razed to the ground and only a brown field remains.
“The pioneer is the man with the arrow in his back”, they said.
