Ganister

(Based on the replies from members of the CIHS to an emailed enquiry, with the addition of background information found through an internet search)

A sandstone with a high silica content which is used in the iron and steel industry. It was used for lining Bessemer converters, and to make silica firebricks or acid refractories. It is a heavy rock, and varies in colour from light to dark grey and pink.

Properties and Composition
Rock type: Quartzose sandstone (orthoquartzite) with a splintery fracture.
Silica content: Roughly 90% to 96% pure silica, bonded with secondary silica cement.
Location: Found globally as “seatearth” layers directly under carboniferous coal beds.

 Uses in Industry
Refractory bricks: Crushed and ground into dust to manufacture heat-proof silica bricks.
Furnace linings: Used extensively in the steel and iron manufacturing industries to line high-temperature industrial furnaces.

In Cumbria
The 1914 List of Mines under the Coal Mines Act lists these mines in Cumberland that produced ganister:

Branthwaite Quarry, Brayton Domain No.4 and No.5, Buckhill (Great Broughton), Gillhead (Flimby, Oatlands (Distington), River Drift (Camerton), Seaton and Seaton Moor, St.Helens No.3 (Flimby), and Wood Drift (Camerton). The full title of the owners of the Gillhead mine was The Gillhead Coal, Firebrick and Ganister Co Ltd.

By 1930 this has reduced to Gillhead, River Drift and Wood Drift.

Bricks
The making of refractory bricks from Ganister was similar to making bricks from other materials. Once mined it was crushed before being ground in a circular wet pan with the addition of water to produce a thick clay which was placed into moulds to dry before being baked in a kiln. In the 1930s orders for Backbarrow Ironworks went to Harrington and Distington

Linings
(At Workington). “I was intrigued to see the query about Ganister, it brought back some hazy distant memories of the time I was employed in the Bessemer shop at Workington in my teens. At the time I only knew that it was a material used to secure the refractory in the Bessemer converters and probably in other vessels like ladles, rather like mortar is used in brickwork. From memory (and it was along time ago) it was like a light cream coloured paste with small chips of lighter material suspended in the mix.”

“A former bricklayer called it “Ganny” and they used it to line the ladles, describing how they would use a small trowel to smooth the lining. If they applied it too thickly it slid down the saddle and would have to be reapplied. When finished, the ladles were inverted over a gas flame to dry them out slowly and thoroughly before use.”

(At Backbarrow). “The casting pot was used a few times but eventually had to be rebuilt and it was lined with soft red sand and patted firm and coated with a carbon like slurry which dried out very firm and that withstood the molten metal coming in. Well they couldn’t have molten metal going into metal. The casting ladles were lined just the same – about 2 or 3 inches thick -that was a much bigger job. There was always a spare ladle to replace one when required. That was a job done on overtime by someone who was skilled enough to do it. Aye they were big. I mean the guys that were lining them had to have a ladder to get up in and out again.”

(Page created 09/08/26)