Wenford Dries
The Wenford Dries were built in the early part of the 20th century (probably post-1907) by the Stannon China Clay Company, to serve the china clay pit at Stannon on Bodmin Moor some 7.2km to the north east. The choice of the site was heavily influenced by the presence of an existing railway line leading from Wenfordbridge which was originally constructed to carry granite from the nearby De Lank quarries. In 1919 the Stannon China Clay Company was acquired by English China Clays Ltd.– at this time the largest china clay producer in Cornwall. Apart from a brief perdiod during WW2, Wenford dries was operational until 2002.
The liquid china clay slurry was carried in a pipeline from the Stannon china clay pit to the Wenford Dries, which is one of the best preserved "pan-kilns" in Cornwall. It is also one of the longest (listed) buidlings in the UK. Pan-kilns consist of 4 major areas, namely sand and mica-drags, settling pits, settling tanks and the “dry” building (or simply the “the dry”). The “dry” building is a long, narrow building with half granite, half brick chimney stacks at one end and a coal-fired furnace at the other end. Internally, the dry consists of 2 terraces. The upper terrace is called the “pan” and was used for drying the china clay, while the lower terrace was called the “linhay” and was used to store the dried china clay before removal by rail or road. Thus, there is often a railway track just below the linhay. The settling tanks, the "dry" with the pan and the linhay and the railway line can still be seen at the Wenford Dries.
Similarly to the Roman hypocaust, the pan was constructed in such a way that hot air was flowing under the floor. The pan’s heating systems consisted of horizontal flues that ran between a coal-fired furnace and the chimneys, which provided the up-draught to draw the hot air under the pan floor. The flues itself were covered by tiles, thus allowing for the wet clay to be spread out, which made it easier to dry.
Chimney stacks with settling tank in front.
Coal fired furnaces.
After the china clay slurry arrived at the pan-kilns it passed through sand and mica drags. The sand drag are made up of concrete channels used to settle out the finer quartz sand from the slurry. Every two hours the drain plugs were removed and the sand drags scraped clean. The slurry now containing only very fine china clay particles, fine sand and flakes of mica enters a series of wooden channels called mica drags. Flowing slowly the slurry drops the mica on to the floor of the channels while the fine clay flows on into the settling tanks. In the settling tanks, the slurry was allowed to settle over a period of days while the water was progressively run off until the clay slurry consisted about 30% to 40% of solids.
The underfloor heating system. The linhay is to the right.
The underfloor heating system.
Once the slurry had the right consistency, a plug was pulled and the slurry passed into the upper terrace of the dry-building or the pan. Here the slurry was spread out on the heated floor and allowed to dry for several days. Once the china clay was dry it was shovelled into the linhay, where it was waiting for removal either by land or rail.
The linhay
The linhay with the remains of the railway track.
Nowadays most of the building is just an empty shell which provides a nice playground for grafitti artists.
Goonbarrow Refinery
The Goonbarrow Refinery is part of the Goonbarrow Pit, the name of which (as far as I can tell) first appeared in the 1841 census. According to the census 7 people were employed at the pit, most of them members of the family than ran the pit. However, it should be noted that between 1830 and 1906 a large number of small china clay works, such as the North Goonbarrow clay works, the Imperial Goonbarrow clay works, the Old Beam clay works (1830-1874), the Bugle Clay Works, and the Rock Hill clay works, operated in the area. The modern Goonbarrow pit was born out out several acquisitions by the English China Clay Company Ltd, which purchased the assets of the Old Beam Mine in 1919, the North Goonbarrow and the Imperial clay works in 1927 and the Rock Hill and Bugle China Clay Companies in 1934. It is interesting to note that some of these mines, i.e. the Old Beam mine and the Rock Hill works operated both as a tin mine and a china clay mine at some stage or the other. In 1999 ECC was acquired by the French company Imetal who subsequently changed their name to Imerys, which now own the Goonbarrow Pit and Refinery. The Goonbarrow Refinery mainly produced performance minerals (such as additives for cement or additives for water-based adhesives) and china clay for the paper industry. A restructuring by Imerys Ltd. in 2007 led to the closure of the Goonbarrow Refinery, which is now in the process of being demolished.
A hydrocyclone which is often used to separate the china clay from impurities. A hydrocyclone ( also simply called cyclone) is a device which allows you to separate or sort particles in a liquid suspension based on the ratio of their centrifugal force to their fluid resistance. This ratio is high for dense and coarse particles (e.g. sand) and low for light and fine particles (e.g. china clay).
Settling Tank at Goonbarrow Refinery
I visited both these sites with @TerminalDecline (all social distancing rules were maintained) who was several amazing reports on the china clay industry on here.
Thanks for looking!
The Wenford Dries were built in the early part of the 20th century (probably post-1907) by the Stannon China Clay Company, to serve the china clay pit at Stannon on Bodmin Moor some 7.2km to the north east. The choice of the site was heavily influenced by the presence of an existing railway line leading from Wenfordbridge which was originally constructed to carry granite from the nearby De Lank quarries. In 1919 the Stannon China Clay Company was acquired by English China Clays Ltd.– at this time the largest china clay producer in Cornwall. Apart from a brief perdiod during WW2, Wenford dries was operational until 2002.
The liquid china clay slurry was carried in a pipeline from the Stannon china clay pit to the Wenford Dries, which is one of the best preserved "pan-kilns" in Cornwall. It is also one of the longest (listed) buidlings in the UK. Pan-kilns consist of 4 major areas, namely sand and mica-drags, settling pits, settling tanks and the “dry” building (or simply the “the dry”). The “dry” building is a long, narrow building with half granite, half brick chimney stacks at one end and a coal-fired furnace at the other end. Internally, the dry consists of 2 terraces. The upper terrace is called the “pan” and was used for drying the china clay, while the lower terrace was called the “linhay” and was used to store the dried china clay before removal by rail or road. Thus, there is often a railway track just below the linhay. The settling tanks, the "dry" with the pan and the linhay and the railway line can still be seen at the Wenford Dries.
Similarly to the Roman hypocaust, the pan was constructed in such a way that hot air was flowing under the floor. The pan’s heating systems consisted of horizontal flues that ran between a coal-fired furnace and the chimneys, which provided the up-draught to draw the hot air under the pan floor. The flues itself were covered by tiles, thus allowing for the wet clay to be spread out, which made it easier to dry.
Chimney stacks with settling tank in front.
Coal fired furnaces.
After the china clay slurry arrived at the pan-kilns it passed through sand and mica drags. The sand drag are made up of concrete channels used to settle out the finer quartz sand from the slurry. Every two hours the drain plugs were removed and the sand drags scraped clean. The slurry now containing only very fine china clay particles, fine sand and flakes of mica enters a series of wooden channels called mica drags. Flowing slowly the slurry drops the mica on to the floor of the channels while the fine clay flows on into the settling tanks. In the settling tanks, the slurry was allowed to settle over a period of days while the water was progressively run off until the clay slurry consisted about 30% to 40% of solids.
The underfloor heating system. The linhay is to the right.
The underfloor heating system.
Once the slurry had the right consistency, a plug was pulled and the slurry passed into the upper terrace of the dry-building or the pan. Here the slurry was spread out on the heated floor and allowed to dry for several days. Once the china clay was dry it was shovelled into the linhay, where it was waiting for removal either by land or rail.
The linhay
The linhay with the remains of the railway track.
Nowadays most of the building is just an empty shell which provides a nice playground for grafitti artists.
Goonbarrow Refinery
The Goonbarrow Refinery is part of the Goonbarrow Pit, the name of which (as far as I can tell) first appeared in the 1841 census. According to the census 7 people were employed at the pit, most of them members of the family than ran the pit. However, it should be noted that between 1830 and 1906 a large number of small china clay works, such as the North Goonbarrow clay works, the Imperial Goonbarrow clay works, the Old Beam clay works (1830-1874), the Bugle Clay Works, and the Rock Hill clay works, operated in the area. The modern Goonbarrow pit was born out out several acquisitions by the English China Clay Company Ltd, which purchased the assets of the Old Beam Mine in 1919, the North Goonbarrow and the Imperial clay works in 1927 and the Rock Hill and Bugle China Clay Companies in 1934. It is interesting to note that some of these mines, i.e. the Old Beam mine and the Rock Hill works operated both as a tin mine and a china clay mine at some stage or the other. In 1999 ECC was acquired by the French company Imetal who subsequently changed their name to Imerys, which now own the Goonbarrow Pit and Refinery. The Goonbarrow Refinery mainly produced performance minerals (such as additives for cement or additives for water-based adhesives) and china clay for the paper industry. A restructuring by Imerys Ltd. in 2007 led to the closure of the Goonbarrow Refinery, which is now in the process of being demolished.
A hydrocyclone which is often used to separate the china clay from impurities. A hydrocyclone ( also simply called cyclone) is a device which allows you to separate or sort particles in a liquid suspension based on the ratio of their centrifugal force to their fluid resistance. This ratio is high for dense and coarse particles (e.g. sand) and low for light and fine particles (e.g. china clay).
Settling Tank at Goonbarrow Refinery
I visited both these sites with @TerminalDecline (all social distancing rules were maintained) who was several amazing reports on the china clay industry on here.
Thanks for looking!
