Lime Kiln Dust; a Dust That Is Screened Out During the Manufacturing of Quicklime

Lime kiln dust (LKD) is a byproduct created when manufacturing Quicklime and is generally disposed into landfills. It is produced when a fine, natural coarse particles of Calcium carbonate (or Limestone) are exposed to high temperature, resulting in the burning of the material and releasing the product. The chemical composition of quicklime and inert material make lime kiln dust an ideal for modifying and drying certain types of soils. Furthermore, lime kiln dust can be used as a binder to stabilize demolition and construction materials.

It is sold in the form of a dry powder that contains a significant percentage of lime along with a substantial amount of inert material. A lime kiln is used to produce quicklime through the calcination of limestone (calcium carbonate), whereas lime kiln dust is a byproduct created when manufacturing Quicklime. There is an increasing demand for LKD in the agricultural sector. Lime kiln dust help enhance soil properties, reduce plasticity, and increase durability and strength. Soils treated with lime kiln dust shows high strength gains.

Thus, there is an increasing demand for LKD in the agricultural sector, as a soil stabilization agent. It also helps in reducing soil moisture and increases the optimum moisture content of the soil. LKD has the unique chemical properties of lime and limestone, along with other inert materials, which make lime kiln dust highly suitable for agricultural use. This in turn also increases the demand for lime kiln dust in the construction industry, especially during the rainy season or in places where the land is not suitable for construction.

Two types of lime kiln dusts, such as soft-burnt and hard-burnt, can be developed as alternative cementitious binders using alkali-activated binder technology. According to Federal Highway Administration, a division of the United States Department of Transportation, around 2 to 4 million tons of LKD are generated in the United States. There are a number of established uses for LKD, but nationally supply has always exceeded demand by a wide margin.