How the lime was made and how it came
The formation of lime slaking lime slurry in lime particle formation of calcium hydroxide colloid structure, fine particles (diameter 1 m), large specific surface area (10 ~ 30 m2/g), the adsorption of a thick layer of water film on the surface, can absorb a large amount of water, and thus have a strong ability to maintain water, which is good water. It can significantly improve the workability of mortar by adding it into the cement mortar and mixing the mortar.Depending on the crystallization and drying of lime carbonation and hardening, the amount of carbon dioxide in the air of low calcium carbonate crust formation and carbonized carbon dioxide to prevent internal penetration, also prevent water evaporation outward, thus hardening slowly, the compressive strength is not high, 1:3 28 d lime mortar compressive strength is only 0.2 ~ 0.5 MPa. In a damp environment, lime moisture in evaporation, carbon dioxide cannot penetrate, hardening will cease; and the calcium hydroxide soluble in water, the hardened lime water will be dissolved away. Therefore, lime is not suitable for use in a long wet and water immersion environment.Lime in the process of hardening, to evaporate a lot of water, causing significant shrinkage of the volume, prone to dry shrinkage cracks. So, the lime is used alone, usually mixed sand, paper, hemp and other materials, to reduce shrinkage, increase tensile strength, and can save lime.The lime has strong alkalinity, and can react with the active silicon oxide or the active alumina in the glass state at room temperature to produce the product with water hardness. Therefore, lime is also an important raw material in building material industry.
Raw materials and production of limeCalcium 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.
Lime is a kind of raw material with high content of calcium carbonate, such as limestone, dolomite, chalk, shell and so on, which is calcined from 900 to 1100 DEG C.The formation of lime is a kind of rock formed by the deposition of calcium carbonate in the sea and sea. Limestone mineral composition is mainly calcite (more than 50%) and some clay, silt and other impurities. The formation and biological role of the vast majority of limestone, biological remains accumulation of limestone coral limestone, coquinoid limestone, algal limestone, limestone in general biology. A limestone formed by the chemical precipitation of calcium carbonate (CaCO3) in an aqueous solution.
