Fireclay

Highley, D.E.

Fireclay

Highley, D.E.. 1982 Fireclay. London, UK, HMSO, 78pp. (Mineral Dossier No. 24)

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Abstract/Summary

The term 'fireclay' is used in a generic sense and is largely restricted to seatclays. Fireclays are non-marine, sedimentary clays consisting essentially of kaolinite, mica and quartz in varying proportions, together with other constituents considered to be impurities, such as ironstone nodules and carbonaceous matter. They therefore exhibit a wide range of physico-chemical properties and no single clay is suitable for every application. Fireclays were originally used for refractory purposes, but they have also important non-refractory applications, mainly in the manufacture of vitrified clay pipes and buff facing bricks, and to a lesser extent in stoneware pottery, sanitaryware and tiles. There is a declining demand for fireclay in its traditional application in the refractory industry, although the use of fireclay in the manufacture of buff facing bricks has increased in recent years. Fireclays, being mainly confined to coal-bearing strata where they commonly, but not always, underlie coal seams, are mainly of Carboniferous age. A major and increasing proportion of total output is therefore derived from open cast coal mines. There are, however, important exceptions, for example, the high quality, refractory fireclays within the Passage Group of central Scotland are not associated with economically important coals. Refractory fireclays are also produced by underground mining. In 1980, United Kingdom production of fireclay was 1.2 million tonnes, its lowest level since records of production began in 1873. There has been a significant decline in the number of mines, mainly underground, since the Second World War, reflecting the increasing production of cheaper fireclays from NCB and licensed opencast coal mines. Present production exceeds demand and large stockpiles have been built up in some areas, particularly in the Midlands. The future of the opencast coal industry has a considerable bearing on the long term availablity of fireclay, but with the recent and proposed increases in open cast coal production concern has been expressed at the loss of fireclay because of the wide imbalance in demand for the two minerals.

Item Type:

Publication - Report

Programmes:

BGS Programmes > Economic Minerals

ISBN:

0115121021

Funders/Sponsors:

Institute of Geological Sciences

Additional Keywords:

Mineral, Fireclay

NORA Subject Terms:

Earth Sciences