Open pan salt making
||The examples and perspective in this article may not represent a worldwide view of the subject. (December 2010)|
In Europe virtually all domestic salt is obtained by solution mining of underground salt formations although some is still obtained by the solar evaporation of sea water. Salt is extracted from the Brine using vacuum pans, where brine is heated in a partial vacuum in order to lower the boiling point. In the past salt has been extracted by heating the brine in pans operating at normal atmospheric pressure, known as open pans.
History of open pan salt extraction
The earliest examples of pans used in the solution mining of salt date back to prehistoric times and the pans were made of ceramics known as briquetage. Later examples were small (3 ft square) pans made from lead using wood as a fuel. After the Middle Ages the pans started to be made from iron, firstly in pans 7 ft (2.1 m) by 8 ft (2.4 m). Gradually the pans increased in size until 'common' salt pans 20 ft (6.1 m) wide and 30 ft long were the norm. The change from lead to iron coincided with a change from wood to coal for the purpose of heating the brine. Brine would be pumped into the pans, and concentrated by the heat of the fire burning underneath. As crystals of salt formed these would be raked out and more brine added.
Occupations in an open pan salt works
- Lumpman: A lumpman would work on pans that made fine salt crystals, which were known as 'fine pans' or 'lump pans'. The quality of the salt depended on the state of the fires which crystallised the salt by forcing off the water. Therefore each pan had its own individual furnace and chimney, which the lumpman was responsible for controlling. Wooden moulds were filled with salt crystals from the pans to produce a hard block (lump) of fine salt. Lumpmen were paid piecework, and would start at 3 or 4 in the morning, and could expect to work 12-16 hour days.
- Waller: A waller would be under the charge of the lumpman, and was responsible for the initial draining of the salt. Salt was drained by being raked to the side of the pans, and then transferred using skimmers onto the hurdle boards (walkways) around the pans. A waller is an ancient name for a saltmaker. He would have been hired on a daily basis.
- Fireman: In addition to the fine pans there were other 'common pans', used to make coarser salt. Because the production of common salt required slower burning fires, it was possible for a single fireman to have charge of several common pans, which could be up to 80 feet (24 m) long.
- Pan-smith: This was originally the name given to the man who made the salt-making pans.
- Grainer process
- Seawater Greenhouse
- Alberger process
- Salt in Cheshire
- History of salt in Middlewich
- Lion Salt Works
- Salt Museum, Northwich
- Saline Luisenhall