ALL ABOUT LIME
Lime (Cal) is the word with which we designate the range of presentations of calcium oxide from calcareous or dolomitic rocks subjected to calcination or hydration and which abound on the earth's surface.
Etymologically, the word cal comes from Latin `calx´ and consists of a white to gray material in its purest basic state CaO or CaMgO when it contains magnesium, or CaOH2 when it is hydrated and it can be transformed by carbonation in CaCO3 calcium carbonate.
Lime has been used in different stages of human evolution, especially in construction, highlighting its qualities of flexibility and resistance over the years.
In addition, less energy is used on its manufacturing than it is to obtain the cement, and lasts longer in time, mainly due to its optimal behavior with water as it does not retain moisture or bring salts to the surface where it is applied. It also has the peculiarity of not requiring additives for curing which makes it a more cost-effective alternative to other adherent mixtures.
However, lime obtained from limestone goes through several chemical processes and from those varieties are obtained which have numerous applications in the production of other materials present in almost all our daily activities.
Applications of quicklime (From Wikipedia)
Steel industry: Used as flux and scorching.
Metallurgy: Used in flotation processes; in the smelting of copper, lead and zinc; in the production of magnesium (you can use two types of manufacturing processes: electrolytic process or thermal reduction process in the latter quicklime is used); In the production of aluminum; And as a scorer of the silica avoiding the formation of aluminum and silica compounds.
Chemistry: Used in the production of soap, in the manufacture of rubber and calcium carbide in the oil industry, the paper industry and cosmetics.
Food: It is used in the sugar industry (particularly in the production of sugar beet ); in oyster farming; in fish farming; in the beer industry, the dairy industry; in the manufacturing of glues and gelatins, in the treatment of wheat and corn; in the wine industry and the conservation of food in food containers "self - heating" in nixtamalization corn dough for corn to make tortillas and all derivatives thereof.
Glass: Its use provides brighter and better color glass. Fusion is faster, which saves money during the glass manufacturing process.
Tannery: It is one of their older applications. Lime milk baths allow removal of hairs and swelling of the skin before tanning.
Infrastructure: In stabilization of soils : to dry wet soils, thaw the frozen and improve the properties of clay soils.
Building: In the manufacturing of prefabricated lime: cell aerated concrete or sand-lime bricks and compressed earth blocks.
Drinking water treatment (purification) is employed to soften, purify, remove turbidity, neutralize acidity and remove silica and other impurities in order to improve water quality people consume.
Wastewater treatment and sludge: it is widely used, in conventional chemical treatment of industrial wastewater basically inorganic character. It is also widely used in the treatment or sludge lines in urban wastewater treatment plants or in organic industrial waters.
Remineralization of desalinated water: The addition of lime allows a desalinated water conditioning which can range from an adjustment of pH and reduced aggression to the remineralization of water by calcium intake. Lime is essential for the final treatment of water from the desalination of sea water since it provides one of the basic nutritional compounds -calcium- and is necessary for the maintenance of the lime-carbon balance, in order to avoid incrustations Or corrosion.
Gas cleaning: Lime, depending on the process, it is the most profitable and natural desulfurizer that removes sulfur dioxide and other acid gases (HCl, HF and NOx) from industrial smoke from incineration of municipal solid waste, thermal plants and The industry in general.
Lime is also used to eliminate persistent organic pollutants (POPs) such as dioxins and furans, and heavy metals from municipal and industrial incinerators.
Waste: The lime addition as a member of various chemical treatments, as an agent to prevent odors and pollution of water by leaching uses.
Treatment of contaminated soils: The techniques used in the treatment of contaminated soils are grouped as follows:
Stabilization - solidification
In the treatment or physical-chemical method (which constitutes a process of transformation of the residue by the addition of a series of chemical compounds to reach the desired objective), the lime is used in the techniques of neutralization, precipitation and dechlorination. With respect to the stabilization / solidification technique (whose main objective is to reduce the mobility and solubility of contaminants present in the soil, reducing its toxicity and eliminating its leaching), there is a variant called "Solidification with lime and pozzolanic materials".
Uses in agriculture are:
Amendment: Lime is used as an amendment to improve the characteristics of agricultural soils: acidity, porosity and soil biological activity.
Fertilizer: Provides calcium is a nutrient for plants.
Compost: Used in the production of compost from agricultural, agro - industrial and urban waste.
Phytosanitary treatments: mixed in the fluids that carry copper to treatment plants to protect those against attacks by fungi such as mildew of the vine, scab or mottling of pear and apple, peach leaf curl, etc.
Biocide: Can be used as a biocide whose purpose is to destroy, deter, render harmless, prevent the action or exercise control otherwise, on any harmful organism by chemical or biological means.
Animal feed: Lime is used as a reagent for its high reaction rate on the production of calcium soaps for the manufacturing of additives and animal feed derived.
In addition, lime is used in acid soils (raising its pH and providing calcium as a nutrient), modifying the composition of the prairies, allowing the development of leguminous species that have better digestibility for cattle and higher protein content. This operation in acid soils will allow a floristic composition needed for a series of species to appear, among them the alfalfa, recognized by the majority of the farmers like the queen of the fodder.
It is a basic product of natural origin that presents two enormous advantages:
Versatility, considering its numerous applications, being, in some of them, essential.