A plant for the extraction of Bromine from sea water was built on the North Quay at Hayle in Cornwall in 1939-1940. The plant was a joint venture between ICI and Associated Ethyl.
The extraction of bromine from sea water was essentially a three stage process, the release of bromine, the capture and concentration and finally, the recovery and purification stage. In the first phase the sea water
was moderately acidified to ph 3.5 and chlorinated to a 10% excess to convert the sodium bromide into bromine and sodium chloride. The second phase collects and concentrates the bromine from 64 parts per
million to a 10% solution, alkaline or acidic, depending on the process.
Over the 32 year life of the plant two processes were operated. From 1940 to 1954 the alkali process collected the liberated bromine in an alkaline solution as sodium bromate. The recovery process used sulphuric acid to liberate the bromine from the alkaline solution.
The design capacity was initially 2500 tons of bromine per year using the “alkali process” and requiring, on average, 30 tons of sulphuric acid, 4.5 tons of chlorine and 11 tons of soda ash per day.
This process was used until 1954 when the plant was converted to the more economic “acid process” with sulphuric acid manufactured on site but requiring 16 tons of chlorine per day for a capacity of 5000tons of bromine per year.
From 1956 the acid process collected the bromine in an acidic solution as 10% Hydrobromic Acid. Chlorine was injected into the solution to convert the HBr to bromine and hydrochloric acid. The significant difference between the two processes is that the alkali process had a far greater sulphur/sulphuric acid demand that the acid process, where 50% of the acid required to acidify the sea water was generated in-situ.
The Hayle works sea water inlet was warmed by the adjacent power station while the processed sea water was discharged at an outfall into the “CopperHouse” pool. This had the disadvantage of partial dilution of the inlet sea water.
Initially large amounts of sulphuric acid were brought to Hayle using a fleet of 20 rail tankers. However in 1949 a Simon- Carves “contact process” sulphuric acid plant was built on site. This also required the construction of a 1200 tons capacity sulphur store on the North Quay.
The first sulphur consignment received in July 1949 was high purity, bright yellow sulphur but this was soon replaced by dark sulphur containing a high ash and tar content. The situation continued until 1954.
During the period of rationing storage became a particular problem. Consignments were 500-600 tons in size but the vagaries of transport and availability meant that there were many occasions when sulphur
had to be stored outside the north wall of the store or on the acid plant yard. Operating losses increased and impurities were a continuing problem.
Off-loading sulphur was always an issue, especially from vessels alongside the Quay. It was a most unpopular operation with Dockers, employees and local people. A handling system was purchased and installed on the western side of the store, comprising hopper, crusher, elevator and conveyor belt. It was always troublesome and required a considerable amount of engineering and maintenance effort before it was finally removed. Subsequently sulphur was loaded into tipper Lorries parked alongside vessels and offloaded directly into the store.
The ethylene for the process was produced from alcohol supplied by Distillers company.
Chlorine for the process was delivered by rail and were usually berthed on the spur line from the old Wharves branch to the Hayle railway line. Close to the present day Clifton Terrace. The Chlorine was initially supplied from the ICI facility in Runcorn , Cheshire but from 1958 the main Octel site at Ellesmere Port was able to produce sufficient Chlorine to supply Hayle.
The main product from Hayle was EDB which was moved in rail tankers to either Northwich or Ellesmere port. From the mid 1960 movement of EDB in Road tankers became more common. Bromine sales were in glass bottles , 4 per wooden case each case holding 33lbs of bromine. In the late 1960s on site bulk storage for around 20 tons of bromine was developed to allow for sales 7.5 or 15 ton demountable road / rail tankers.
In 1973 the need for significant capital expenditure to replace ageing equipment resulted in the decision to close down the site. By 1974 the site was cleared.
I would like to thank Arthur Fairhurst the former Works Manager at Octel Hayle for information on this page.