Limestone Main Ingredients Calcium carbonate (CaCO3). Lime and limestone are a lot of raw materials for building materials, industrial. Limestone can be processed directly into stone and fired into lime. Lime CaO absorb moisture or add water to become slaked lime, slaked lime is the main component of Ca (OH) 2, can be called calcium hydroxide, hydrated lime by the deployment of lime slurry, lime paste, used as a coating material and brick adhesive The
Calcium carbonate is a compound of the formula CaCO3. CAS No. 471-34-1. It is a common substance on earth that can be found in rocks. Animal back shell and snail shell of the main ingredients. It exists in the nature of calcite and aragonite minerals. Calcite is a triangular crystal, hexagonal crystal, pure calcite colorless and transparent, usually white, containing 56% CaO, 44% CO2, the density of 2.715g / cm3, Mohs hardness of 3, the nature of more brittle. Artifacts are orthodox lines, diamond-shaped crystals, gray or white, the density of 2.94g / cm3, Mohs hardness of 3.5-4, dense nature. The physical size of limestone in the calcite is the size of the crystal is very important. The dense limestone exhibits a low porosity of the fine-grained crystal structure with high strength. The density of limestone is about 2.65 ~ 2.80g / cm3, dolomite limestone is 2.70-2.90g / cm3 and dolomite is 2.85-2.95g / cm3. The bulk density depends on the porosity.
Limestone thermal expansion: The data show that the average coefficient of thermal expansion of microcrystalline limestone is (4.5 to 5.0) * 10 ^ (-6) / ° C and the coarse crystal is increased to 10.1 * 10 in the range of 800 ° C or less ^ (- 6) / ° C. The limestone heating experiment is very important in the production of lime. At 800 ° C below the decomposition point of the limestone, the limestone crystals develop in the crystal, and cracks are formed in the highly crystallized limestone, and those crystals are made into a powder by heating, which is well developed for crystallization and contains many Dense calcite limestone powder is more serious.
Limestone, the main component of calcium carbonate, the most important chemical properties is the higher temperature decomposition into calcium oxide and carbon dioxide, in addition to the following chemical properties.
l) Chemical resistance
In addition to acid, many erosive substances can not erode or only slow down the limestone.
2) acid resistance traits
Limestone reacts with all strong acids to produce calcium salts and emit carbon dioxide. The rate of reaction depends on the impurities contained in the limestone and their crystal off size. The higher the impurity content, the larger the crystal, the smaller the reaction rate. The reaction rate of dolomite is slower than that of limestone. Dolomite, limestone Determination of the method: 10% hydrochloric acid drops in the dolomite with a small amount of bubbles, dripping on the limestone is violent to produce odorless bubbles, the resulting gas can make clear lime water becomes turbid.
3) resistance to various gas traits
Chlorine and hydrogen chloride in the dry state and room temperature and CaCO3, the reaction is very slow, until 600 ℃ after the start to accelerate the formation of CaCl2; sulfur dioxide at room temperature, whether it is gaseous or liquid on CaCO3 have no significant effect; and nitrogen dioxide NO2) reacts with CaCO3 at 15 ° C to produce Ca (NO3) 2, NO and CO2.
Engaged in mining workers often appear on the upper respiratory tract inflammation, bronchitis, may be associated with emphysema. X-ray showed lymph node calcification, enhanced lung texture. Work workers suffering from pneumoconiosis mainly with the goods contained in the impurities related to silica.
Isolated from contaminated areas, restricted access. It is recommended that emergency personnel wear dust masks (full cover) and wear general work clothes. To avoid dust, carefully swept away, placed in the bag transferred to a safe place. If a lot of leakage, covered with plastic cloth, canvas. Collected or transported to waste disposal sites.