Views: 102
Calcium carbonate is a kind of inorganic compounds, commonly known as grey stone, limestone, calcite, limestone, marble, is a kind of compounds, chemical formula optimization is CaCO ₃, show neuter, basically does not dissolve in water, soluble in acid.
It is a common material on the earth, existing in aragonite, calcite, chalk, limestone, marble, travertine and other rocks.It is also the main component of animal skeleton or shell.Calcium carbonate is an important building material and is widely used in industry.
The whiter the calcium carbonate, the higher the purity.Because CaCO3 will have a small amount of decomposition into CaO and CO2 under natural conditions, and CaO will react with water molecules in the air to form Ca(OH)2.
So, how can we improve the whiteness of calcium carbonate?
I. Light calcium carbonate
The production method of light calcium carbonate is carbonization and the raw material is high-quality limestone.The content of CaCO3 is greater than 96%.
If limestone raw material contains iron, manganese and other metals, will reduce the whiteness of light calcium carbonate.
Therefore, if you want to improve the whiteness of light calcium carbonate, can be in the process of digestion, or carbonization process, or cooked slurry to add reducing agent, complexing agent, such as sodium disulfite, DETA, triethanolamine and other agents compound, whiteness can increase 2 ~ 6%, the finished product whiteness can be increased to more than 94%.
II, Heavy calcium carbonate
First of all, we must strengthen management and improve the level of equipment.Heavy calcium carbonate production equipment a penny a goods, at the same time the timely overhaul and maintenance of equipment is also important.
Secondly, the choice of raw ore to fine selection.Can analyze whether the iron in the ore exceeds the standard, general requirements Fe2O3≤0.1%, more than 0.2%, the product will be yellow or even red resulting in a decrease in whiteness, then need to go through a chemical preparation iron removal treatment, such as iron pollution caused by equipment, can also be the same treatment, if not iron exceeds the standard can not use this method, otherwise will reduce the whiteness.
III. Yhe compreheTsive analysis of calcite and product calcium carbonate chemical composition.
If other impurities in the ore exceed the standard, will also cause the whiteness is not high.At this time through multistage slag removal treatment as much as possible to increase the whiteness, generally limited improvement, the best ore.If the color mineral itself is high, bleaching techniques should be used to improve the whiteness of calcium carbonate products.
According to the pigment ion contained in calcite and product calcium carbonate, some methods are needed to bleach heavy calcium carbonate.Heavy calcium carbonate bleaching will generally be chemical agents in the crushing process, crushing and bleaching.Through the above method, can improve the whiteness of heavy calcium carbonate.
