Towards a Minerals Local Plan for Derbyshire and Derby

Towards a Strategy for Brick Clay and Fireclay

Introduction

Introduction and Background

1.1     Clay, shale and mudstones are fine grained sedimentary rocks that occur extensively in the United Kingdom. Despite being widespread, only limited deposits of clay, shale and mudstones have sufficient qualities to make them economically important minerals. (When they are extracted for commercial use they are generally known by the term ‘clay and shale’)[1].

1.2     Brick clay is the term used to describe clay and shale used in the manufacture of structural clay products, notably facing and engineering bricks, pavers, clay tiles for roofing and cladding, and pipes. Brick manufacture is the largest use by tonnage of brick clay and bricks are one of the most visible components of the built environment in our villages, towns and cities. Most brick clays are red firing, producing red coloured products. Fireclays are sedimentary mudstones that underlie almost all coal seams and are particularly important for the manufacture of buff and pale-bodied facing bricks[2].

1.3     Traditionally, there has been a close association between the brick works and brick clay working site. However, since the 1960s, brick manufacturing capacity has reduced and changed in character, from numerous small brickworks to larger and fewer automated plants which require different sources of clays for blending. The close association of fireclay and coal means that supply of fireclays is highly dependent on surface coal mining operations.

 

 

Further more detailed information regarding Brick and Fireclay is available in the Brick and Fireclay Supporting Paper, January 2015

1.4     Clay and shale can also be used for engineering and environmental purposes i.e. capping and lining areas of landfill and lining water bodies for general constructional purposes (fill).  Clay and shale are also used in the production of cement.  

Further more detailed information about the use of clay and shale in cement production is dealt with in the Paper, Towards a Strategy for the Provision of Industrial Limestone, February 2015 and in the Cement Supporting Paper, February 2015  

 

1.5     Mineral Resources

          Clay, shales and mudstones occur extensively in the Plan area but, only a small proportion are suitable for brick or clay products manufacture (most are too high in carbon and sulphur). The most important economic resources, shown on the Map (Clay Resources, Quarries and Manufacturing Sites – 2014), are of Carboniferous age and are associated with the Millstone Grit and the Coal Measures, the latter being also a potential source of fireclays. The red silty mudstones of the Triassic, Mercia Mudstone Group outcrop extensively in the southern part of the County but are not of economic importance.

 

1.6     Method of Working/Processing/Transport/Restoration

          Brick clays are worked entirely by open pit methods in shallow or deep quarries. The extraction is undertaken in a ‘campaign’ where there is a concentrated short period of excavation, usually on an annual basis. The nature of extraction varies, but typically, within the Plan, area annual clay and shale extraction is small scale in terms of tonnage (around 50,000), with some sites operating for many years. More recently brick clay has been also been excavated as a by-product of large scale surface coal working involving the rapid exploitation of the clay and shale jointly with coal. A feature of brick clay working is the need to extract and store clays selectively to avoid contamination and ensure a consistent raw material.  Clay is stockpiled in the open air for several months to enable weathering which increases its ability to be moulded. Fireclay extraction is not normally commercially viable on its own and almost all production is as a co- or by-product of surface coal production. Where fireclay is recovered for sale, it must be worked carefully to ensure that there is no contamination with the associated coal.

          Most facing bricks, engineering bricks and related clay based building products are manufactured in large automated factories. Clay is transported to the plant by road and the finished product is usually delivered to the market by road. Blending different clays to achieve improved durability and to provide a range of fired colours and textures is an increasingly common feature of the brick industry.

          The nature of the brick clay market raises particular issues for clay working in terms of the length of time taken to work and restore sites. Fluctuations in the economy impact on the construction industry and the consequent demand for structural clay products, especially bricks, which impacts on the demand for clay. Periods of economic recession may lead to mothballing or closure of extraction and processing facilities, including brickworks, thus prolonging the working and restoration of clay sites. Where brick or fireclay is worked in association with surface coal mining, schemes usually require short extraction periods with quick restoration which limits stockpiling opportunities. Clay may be stocked at the brick works/clay products manufacturing site, rather than at the excavation site.

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1.7     Demand

          A recent report[3] on trends in the UK production of Minerals states that brick clay consumption has declined significantly since the 1970s from 18 million tonnes in 1974 to 4 million tonnes in 2011. The initial decline was mainly attributable to the demise of common bricks in houses as a result of alternative construction methods and smaller houses. More recently the decline can be attributed to a significant reduction in the number of new houses built, however, with increasing pressure for new homes, the declining trend in house building is likely to be reversed.  How far this translates into an increased demand for brick clay or imports of bricks, in the light of the above trends in unit size and construction methods, remains to be seen. In the past the United Kingdom has largely been self-sufficient in the manufacture and supply of bricks, but since the late 1990s there has been an increasing reliance on imports.  The above factors, together with the reduction in the scale of surface coal mining have also led to a decline in the consumption of fireclays.

1.8     Production and Reserves

          The recent economic downturn and resultant recession in the construction sector means that the demand for building products and hence brick and fireclay is low. This national picture is reflected within the Plan area. Currently there are only three sites with planning permission for brick clay working and one active surface coal mining site where incidental fireclay is being extracted. Annual production, permitted reserves and estimates of the lifespan of existing quarries are shown on the Table below. The locations of the quarries and the brickworks/clay products site they serve are shown on the Map (Clay Resources, Quarries and Manufacturing Sites - 2014). There are currently no brickworks within the Plan area and all brick clay excavated is exported to adjoining mineral planning authority areas. The fireclay extracted at Lodge House, Smalley will be used within the Plan area, to supply the nationally renowned pottery manufacturers at Denby.

 

 

          Production and permitted reserves at clay and shale quarries within the Plan area, 2014

Quarry

Production

2011

Production

2012

Production

2013

Permitted Reserves

2013

Anticipated annual production over plan period

Estimated lifespan of sites ( in years) based on estimated average production over plan period

Estimated date that permitted reserves will be worked out based on estimated average production over plan period

Expiry date of planning permission

Brick Clay

               

Mouselow

61,000

18,000

45,000

405,000

(1,650,000)*

45,000

9

2022

2042

Waingroves

81,000

66,000

69,000

3,050,000

80,000

38

2053

2042

Foxlow Tip

     

250,000 *

 

N/A

N/A

2029

Totals

142,000

8,400

109,000

4,950,000

       

Fireclay

               

Lodge House Farm

     

50,000

 

Development to be completed between 2011-2015

2015

2015

Totals

     

50,000

       

All figures in tonnes

* See explanation of reserves figures below

 

1.9     Mouselow

          A clay and shale quarry, operated by Wienerberger UK, is located at Mouselow, near Glossop; this site supplies the company’s Denton brickworks, Manchester approximately 10 miles away. The operator obtained planning permission in December 2014 to vary a time limited planning condition on the site which extends the period of working from 2019 to 2042, enabling some 1,450,000 tonnes of permitted shale reserves at the quarry, to be worked throughout the Plan period and beyond.

          More recently, January 2015, the operator has submitted evidence indicating that, after recent trialling, because of the high carbon content, a large proportion of the permitted reserves (i.e. the lower shale reserves) are not economic to use on their own without blending with the upper shale reserves. This greatly reduces the availability of suitable brick making reserves from the quarry. Based on a future annual production of 45,000 tonnes (as set out in the planning application[4]), the quarry has only sufficient reserves of upper shales to last for approximately 9 years. (This calculation takes into account the use of a small quantity of lower shales for blending purposes).

          To compensate for this loss of reserves, the operator is promoting, through the local plan process, a small extension to the area of extraction within the permitted site, (as shown on the Map: Mouselow Quarry) which will generate a further 1,400,000 tonnes of upper shale. These additional reserves of high quality brick making shale will ensure the supply of material to Denton beyond the Plan period. Planning permission will be required to enable mineral to be extracted from this area. Further details are set out in the Appendix.

1.10   Waingroves

          Permitted reserves at Waingroves (operated by Hanson UK) total some 3.05 mt. The operator estimates that production is likely to increase again in 2014 to the 2011 levels of around 80,000 tonnes. Using this figure as an indication of future annual demand, Waingroves could maintain supplies at this level for a further 38 years, well beyond the Plan period. The planning permission includes conditions requiring on- going restoration including site profiling, planting and landscaping. The site supplies the operator’s brickworks at Kirton, Nottinghamshire and at Measham and Desford, Leicestershire.

1.11   Foxlow Tip

          Permitted reserves at the Foxlow Tip site, Staveley (operated by SUON) total some 250,000[5] tonnes of stockpiled material. The planning permission contains a condition restricting the use of the clay in association with the Phoenix Brickworks at Barrow Hill, which has since been demolished. Planning permission has been granted for a waste treatment plant adjoining the former brickworks site. If the treatment plant is developed and performs as expected the operator has indicated that it could provide sufficient energy to make the development of a new brickworks a viable proposition in view of the stockpiled material and other nearby resources.

1.12   Lodge House Farm

          A small amount (up to 50,000 tonnes) of potential marketable fireclay has been extracted at Lodge House Farm, Smalley in association with surface coal mining. This clay will be used to supply the nearby pottery manufacturers at Denby. Development of the site began in 2011 and is expected to be completed by the end of 2015.

 

1.13   Other uses of clay and shale

          Clay and shale is also used for engineering and environmental purposes. These uses don’t require the specialist properties of brick clay or fireclay and therefore the extensive clay and shale deposits within the Plan area can be used to source them.

 

[1] Page 10, British Geological Survey, Commissioned Report CR/03/281N - Definition and characteristics of very fine grained sedimentary rocks: clay, mudstone, shale and slate, 2003,

[2] Page 17, Trends in UK Production of Minerals, UK Minerals Forum, January 2014

[3] Page 17, Trends in UK Production of Minerals, UK Minerals Forum, January 2014

[4] Planning Application CM1- 0214 -162 to vary conditions of planning permission R1/0310/24 to alter restoration landform and extend the end date for winning and working of minerals at Mouselow Quarry, Wienerberger Ltd, January 2014, Vol 2 Non Technical Summary

[5] Information supplied from SUON 19/9/2013