The original lime production process is the limestone and fuel (wood) layered laying, firing a week. Modern machinery, semi mechanized shaft kiln and rotary kiln, boiling furnace and other equipment for production. The calcining time is shortened correspondingly, and the production of lime in rotary kiln is only 2 to 4 hours, and the production efficiency can be increased by more than 5 times. The utility model has the advantages of a cross flow type, a double slope type, a rotary kiln for burning oil and a short rotary kiln with a preheater, etc., and the utility model has the advantages of obvious energy saving effect, and the fuel is also expanded into coal, coke, heavy oil, liquefied gas, etc..
Calcium carbonate as the main component of natural rocks, such as limestone, chalk, dolomite limestone, can be used to produce lime.The main component of the natural calcium carbonate rock, calcined at appropriate temperature, the removal of the decomposition of carbon dioxide, the resulting calcium oxide (CaC) as the main component of the product that is lime, also known as quicklime.In the actual production, in order to speed up the decomposition, calcination temperature often increased to 1000 ~ 1100 C. Due to the large size of limestone raw material or the uneven distribution of temperature in the kiln, lime and lime are often contained in lime. The calcium carbonate in the lime is not completely decomposed, and the adhesive force is not used. The burnt lime structure is dense, the surface is often covered with a layer of molten material, and the curing is slow. Because the production of raw materials often contain magnesium carbonate (MgCO3), because this lime also contains minor components of Magnesium Oxide (MgO), according to the number of Magnesium Oxide content, lime into calcium lime (MgO = 5%) and magnesia lime (MgO>5%).Quicklime is white or gray block, in order to facilitate the use of bulk lime often need to be processed into quicklime powder, lime powder or lime cream. Lime powder is composed of massive pulverized quicklime obtained by fine powder, the main ingredient is CaO; lime powder is lump lime with water curing powder obtained, also called slaked lime, its main component is Ca (OH) 2; lime paste is lump lime with more water (about 3 - 4 times the volume of lime) obtained by curing paste. Also called lime slurry. Its main component is Ca (OH) 2.
The effective component of lime is the effective calcium oxide and Magnesium Oxide. The effective calcium oxide content in lime and Magnesium Oxide can be determined directly, can also be through the total content of calcium oxide and carbon dioxide with Magnesium Oxide's reflection, lime and undigested residue content requirements; lime powder with fineness requirements; lime powder and the volume stability, fineness and free water content requirements.The national building materials industry will be divided into three grades: building quicklime, building quicklime powder and building slaked lime powder. But in the transportation sector, JTJ 034 - 2000 "highway pavement base construction technical specification" is still in accordance with the original national standard (GB1594 - 79) will be divided into quicklime and slaked lime.
