Modern Chemicals
In contrast to its later dominance, the chemical industry made a rather tentative appearance on Teesside, encouraged by the area’s transport network. Its establishment can possibly be attributed to Robert Wilson of Yarm who founded the Egglescliffe Chemical Company at Urlay Nook, adjacent to the Stockton and Darlington Railway in 1833. The firm specialized in the synthesis of sulphuric acid, which they employed in the production of fertilizer. Continuing to serve the agricultural trade, the Egglescliffe Chemical Company expanded in 1865 to include linseed oil and cake mills.
Processes connected with the iron trade produced noxious gases that happen to contain useful chemicals and Bell Bros led the way in their recovery by extracting coal tar from their coke emissions. In 1868, Sadler and Co. established works at Cargo Fleet for the distillation of this tar, becoming the first to extract and market benzene.
Much of the chemical industry relied upon huge deposits of evaporites (sediments formed by the evaporation of saline water). These were laid down during the Permian Period about 250 million years ago around the margins of the Zechstein Sea, which then stretched from Yorkshire eastwards across much of northern Europe. Subsequently, the deposits were deeply buried under thousands of metres of sediments including the Jurassic rocks that form the present land surface. The evaporites include halite (rock or common salt, sodium chloride), potash (sylvite, potassium chloride) and anhydrite (calcium sulphate), all three of which have been utilised.
Salt
An unexpected offshoot of the iron trade came as the result of profiteering on the part of the Darlington water company whose prices rose steadily in the early 1860’s. Bolckow, Vaughn and Co. made a borehole at their Vulcan Street works in an attempt to secure a free water supply of their own but rather than water it revealed the presence of a bed of salt 100ft thick (30m) at a depth of 1,300 feet (396m). They tried to sink a shaft to the deposit but constant flooding meant it was eventually abandoned. A decade passed before Bell Bros., at their Port Clarence works, located the same bed at a depth of 1100 ft (335m) and again flooding meant they had to abandon the task. In 1882 the introduction of the hydraulic method of salt extraction from Alsace in France, meant they could now extract the salt. Fresh water was pumped down boreholes and the resulting brine extracted. It was then evaporated to collect the salt. Bell Bros. were the first to respond, quickly followed by Bolckow, Vaughan and Co, Pease and Partners and the Cleveland Salt Company. By the mid 1890s production amounted to 300 000 tons per annum, the majority of which was shipped to Tyneside for the alkali industry. An interesting development came in 1890 when Mr. Weddell began selling salt in a packet form, one of the first to do so. This was the beginning of Cerebos, which later became virtually a brand name for salt. In 1906 he began a factory at Greatham, which subsequently added BISTO, a new gravy powder to their list of products. Eventually the industry extended along both sides of the river. Extraction ceased in 1971 but it had resulted in the formation of huge underground cavities. Some of these are used for storage of gases, and lately applications have been made to utilise others for the storage of hazardous waste.
The principal uses of sodium carbonate are in the manufacture of glass and the production of chemicals. It is also used in processing wood pulp to make paper, in making soaps and detergents, in refining aluminium and in water softening.
Anhydrite (anhydrous calcium sulphate) formed in the same way was mined at Hartlepool and Billingham and was used for the production of ammonium sulphate, which is used as an artificial fertiliser and in the production of explosives.
Potash
The deposits are mined today at Boulby near Staithes. There are two 1150m deep shafts put down to develop a seam of potash about 7.5m in thickness and with an average grade of 35% potassium chloride. Production commenced in 1973 and is currently about 1 million tonnes per year of potash for use in the chemical and agricultural industries. In addition, large amounts of rock salt co-product are mined and mainly used for gritting roads.