Find out some useful and interesting lime facts. Lime is an important material that is used in many different industries. Lime has been used for thousands of years.
Lime is made by burning off the carbon dioxide from limestone, natural chalk or sea shells by heating. Blowing air between 1100° and 1200° drives off CO2 (carbon dioxide). This results in a material called quicklime (CaO).
Quicklime absorbs 40 percent of its weight in water. Quickline (CaO) absorbs water to become Ca(OH)2.
Types of Lime
Quicklime is produce by heating limestone, natural chalk or seashells. Dolomite, which is another type of sedimentary rock, is also used to make quicklime.
Hydrated lime is made from quicklime. To make hydrated lime suppliers crush quicklime then add water. Hydrated lime is more expensive than quicklime because extra work is required to produce this type of lime.
Lime kiln dust, also known as LKD is a waste product captured during the production of quicklime. Filter bags are used in rotary kilns to collect the dust produced during quicklime production. These filter bags stop air pollution. The dust that is collected is known as lime kiln dust. Millions of tons of LKD is produced each year. People are finding new uses for LKD. The cost of lime kiln dust is close to half the cost of quicklime.
Uses of Lime
Lime is used to make mortar to bond bricks and blocks. When lime is mixed with sand and water, it makes mortar. Although lime was used to make mortar from Roman times and perhaps earlier, from about 1900 mortar was changed to a Portland cement mix. Recently, lime mortars have again become popular because of its durability.
Lime is used to make plaster, which is used inside and outside of buildings for walls, ceilings, stucco and more.
Hydraulic lime, which is made from limestone and clay is used for mortar and plaster on the exterior or buildings and for bonding water and sewer pipes.
Non-hydraulic lime is typically used indoors.
Lime has a high melting point of over 2500°C. This makes lime a useful product in the construction industry because high temperatures and fire do not damage lime.
When lime is heated and mixed with silica sand (SiO2) and sodium carbonate (Na2 CO3) it makes a mixture that hardens into glass.
Lime is the main ingredient in Portland Cement. Portland cement is the material that bonds concrete together.
One of the uses of lime is to help neutral water or liquid. Lime is used in water and sewage treatment to help neutralize liquids with a low pH. Lime is also used to clean up or neutralize acidic waste water from mine runoff or acid spills. Treatments made with lime are used in swimming pools to help keep the water neutral.
Lime has a pH in the range of 12 to 13. With a pH this high lime is considered a base. A pH of 7 is considered neutral.
More ways people use Lime
Lime is used in the highway construction industry. Geotechnical engineers use lime to stabilize soft soils under pavement. A mixture of 4 to 6 percent lime is mixed into the soft soils and then compacted After a curing period, the soft soils stiffen allowing construction of the asphalt or concrete roadway pavements. Lime kiln dust (LKD) is also used to stabilize soft soils.
Without lime the way steel is made would change. Lime is used as a flux to remove contaminants such as phosphorus and sulfur from molten iron ore. The contaminants are attracted to the lime. The lime then floats to the top because it is lighter than metal and the lime and contaminants are removed.
Farmers use lime to balance the pH in soil to improve soil growing conditions. Lime has a high pH. Certain crops or water conditions cause soil to have a low pH (acidic). Farmers spread and disc the lime into the soil to improve the soil from growing the next year.