Steetley Magnesite used to produce magnesia for use in refractory products for the steel industry. Steetley Magnesite pioneered a new method of extracting magnesia from dolomitic lime using sea water. As the site at Steetley on the Hartlepool Headland increased in size, so did the output. At its peak, Steetley was producing 250,000 tonnes a year. After the tough 1980's and the decline of British Steel, the company was struggling but managed to carry on despite a few name changes until 2005 when production stopped for good.