Potash pits were kiln sites which were dug and lined with drystone walling for the production of potash prior to the Industrial Revolution. The scouring or degreasing of the natural lanolin from wool requires the application of soft soap produced using fat and an alkaline potash solution [1] that contains water-soluble potassium salts such as potassium carbonate and potassium hydroxide. [2]
The potash pit was a basic stone lined ashery in which hardwoods such as birch wood or bracken were burned to produce ashes which were then placed in a copper cauldron manufactured from strips of copper and boiled together with water and quicklime. [1] The alkaline solution produced by the ashes and added quicklime could be filtered to remove particles and once the required alkalinity was reached fats were added to produce a soft soap for the scouring or degreasing of the wool as a vital step in the production of wool for spinning into yarn.
Many potash pits were built in or near areas of suitable deciduous woodlands [1] and as such they are an important landscape features indicating both the processing of wool and the presence of a suitable hardwood woodland present at the site or nearby at the time that potash pits were in use. [3]
The often circular pits were built often into earthen banks and were lined with drystone walling. A tunnel fireplace was required to draw in the air for the burning conversion of the birch, bracken, etc. into ashes, used for heating the cauldron as well as the source of the potash. [1]
The pits are a feature found in sheep farming districts with extensive woodlands such as the Lake District in England. One example is located in the Lickle Valley, [4] Broughton in Furness. [1]
As a landscape feature, the remains of potash pits are superficially similar in appearance and location to Q-pits that were constructed to make white coal for use in smelting lead. Saw pits were constructed in areas of woodland also, however they were rectangular in shape and are easily distinguished from the aforementioned.
In chemistry, an alkali is a basic, ionic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The adjective alkaline, and less often, alkalescent, is commonly used in English as a synonym for basic, especially for bases soluble in water. This broad use of the term is likely to have come about because alkalis were the first bases known to obey the Arrhenius definition of a base, and they are still among the most common bases.
Potassium is the chemical element with the symbol K and atomic number 19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure. It was first isolated from potash, the ashes of plants, from which its name derives. In the periodic table, potassium is one of the alkali metals, all of which have a single valence electron in the outer electron shell, which is easily removed to create an ion with a positive charge. In nature, potassium occurs only in ionic salts. Elemental potassium reacts vigorously with water, generating sufficient heat to ignite hydrogen emitted in the reaction, and burning with a lilac-colored flame. It is found dissolved in seawater, and occurs in many minerals such as orthoclase, a common constituent of granites and other igneous rocks.
Potash includes various mined and manufactured salts that contain potassium in water-soluble form. The name derives from pot ash, plant ashes or wood ash soaked in water in a pot, the primary means of manufacturing potash before the Industrial Era. The word potassium is derived from potash.
Soap is a salt of a fatty acid used in a variety of cleansing and lubricating products. In a domestic setting, soaps are surfactants usually used for washing, bathing, and other types of housekeeping. In industrial settings, soaps are used as thickeners, components of some lubricants, and precursors to catalysts.
Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations Na+ and hydroxide anions OH−.
Bracken (Pteridium) is a genus of large, coarse ferns in the family Dennstaedtiaceae. Ferns (Pteridophyta) are vascular plants that have alternating generations, large plants that produce spores and small plants that produce sex cells. Brackens are noted for their large, highly divided leaves. They are found on all continents except Antarctica and in all environments except deserts, though their typical habitat is moorland. The genus probably has the widest distribution of any fern in the world.
A lye is an alkali metal hydroxide traditionally obtained by leaching wood ashes, or a strong alkali which is highly soluble in water producing caustic basic solutions. "Lye" most commonly refers to sodium hydroxide (NaOH), but historically has been used for potassium hydroxide (KOH).
Potassium hydroxide is an inorganic compound with the formula KOH, and is commonly called caustic potash.
Potassium carbonate is the inorganic compound with the formula K2CO3. It is a white salt, which is soluble in water and forms a strongly alkaline solution. It is deliquescent, often appearing as a damp or wet solid. Potassium carbonate is mainly used in the production of soap and glass.
Saponification is a process of converting esters into soaps and alcohols by the action of aqueous alkali. Soaps are salts of fatty acids, which in turn are carboxylic acids with long carbon chains. Sodium stearate is a typical soap.
Saponification value or saponification number represents the number of milligrams of potassium hydroxide (KOH) or sodium hydroxide (NaOH) required to saponify one gram of fat under the conditions specified. It is a measure of the average molecular weight of all the fatty acids present in the sample in form of triglycerides. The higher the saponification value, the lower the fatty acids average length, the lighter the mean molecular weight of triglycerides and vice versa. Practically, fats or oils with high saponification value are more suitable for soap making.
An ashery is a factory that converts hardwood ashes into lye, potash, or pearlash. Asheries were common in newly settled areas of North America during the late 18th century and much of the 19th century, when excess wood was available as settlers cleared their land for farming. Hardwood ashes contain abundant levels of potassium carbonate and potassium hydroxide, the principal components of the products being produced.
Q-pits are kiln sites which were dug for the production of white coal prior to the Industrial Revolution when white coal was largely superseded by the use of coke.
The textile bleaching is one of the steps in the textile manufacturing process. The objective of bleaching is to remove the natural color for the following steps such as dyeing or printing or to achieve full white. All raw textile materials, when they are in natural form, are known as 'greige' material. They have their natural color, odor and impurities that are not suited to clothing materials. Not only the natural impurities will remain in the greige material, but also the add-ons that were made during its cultivation, growth and manufacture in the form of pesticides, fungicides, worm killers, sizes, lubricants, etc. The removal of these natural coloring matters and add-ons during the previous state of manufacturing is called scouring and bleaching.
Forest glass is late medieval glass produced in northwestern and central Europe from approximately 1000–1700 AD using wood ash and sand as the main raw materials and made in factories known as glasshouses in forest areas. It is characterized by a variety of greenish-yellow colors, the earlier products often being of crude design and poor quality, and was used mainly for everyday vessels and increasingly for ecclesiastical stained glass windows. Its composition and manufacture contrast sharply with Roman and pre-Roman glassmaking centered on the Mediterranean and contemporaneous Byzantine and Islamic glass making to the east.
Wood ash is the powdery residue remaining after the combustion of wood, such as burning wood in a fireplace, bonfire, or an industrial power plant. It is largely composed of calcium compounds along with other non-combustible trace elements present in the wood. It has been used for many purposes throughout history.
Wet Processing Engineering is one of the major streams in Textile Engineering or Textile manufacturing which refers to the engineering of textile chemical processes and associated applied science. The other three streams in textile engineering are yarn engineering, fabric engineering, and apparel engineering. The processes of this stream are involved or carried out in an aqueous stage. Hence, it is called a wet process which usually covers pre-treatment, dyeing, printing, and finishing.
Seidlitzia rosmarinus is a perennial-green desert species of saltwort in the Amaranthaceae family. It is endemic to the lower Jordan Valley along the Dead Sea, in Israel and Jordan, and in the Syrian desert, Central Iraq and in the coastal regions of Saudi Arabia, the islands of Bahrain, Qatar, and Iran, commonly known in Arabic by the names ʾušnān and šenān and in the Neo-Aramaic languages by reflexes of ʾuḥlā. It is often used by Bedouins for cleaning as a soap substitute. In medieval Arabic literature, it is also known by the names of "green ushnan" and "launderers' potash", having been used since time immemorial to produce nabulsi soap and as an electuary in compounding theriac for use in treating scorpion stings, as well as for extracting potassium for other medicinal uses.
Scouring is a preparatory treatment of certain textile materials. Scouring removes soluble and insoluble impurities found in textiles as natural, added and adventitious impurities, for example, oils, waxes, fats, vegetable matter, as well as dirt. Removing these contaminants through scouring prepares the textiles for subsequent processes such as bleaching and dyeing. Though a general term, "scouring" is most often used for wool. In cotton, it is synonymously called "boiling out," and in silk, and "boiling off."