Powell Duffryn’s coke ovens and by-product recovery plant at Bargoed were a fine example of colliery enterprise. The company used some innovative methods to fully utilise the by-products of the raised coal. This included washing small coal, coking in re-generative by-products ovens, the manufacture of sulphuric acid and sulphate of ammonia and tar distillation. There was also a benzol plant and an ammonia plant. Some of the coal by-products produced were presotim (a wood preservative), presomet (a black bituminous paint for metals) and syntharar and synthacold (tar products for road services).
There are many files of correspondence (1917-1951) of Joseph West who was manager of Bargoed Laboratory, then later kept on by the National Coal Board as Carbonisation Officer for No 5 (South Wales) Area. The files include analysis of coal and its by-products, details of coke production and shipments, correspondence specific to certain chemical processes, the ammonia plant, and gasholders and purification. The collection also includes goods outwards books (1925-1951) and would make an excellent resource for historians interested in the ancillary activities of the coal mining industry.