How to distinguish heavy calcium from light calcium
1. Density of light and heavy calcium carbonate:
The density of light calcium carbonate is 2.4ー2.6 G / cm 3, that of heavy calcium carbonate is 2.6ー2.9 G / cm 3.
2. Light Calcium Carbonate vs. heavy calcium carbonate:
Light Calcium carbonate, also known as precipitated calcium carbonate, or light calcium for short, is formed by burning sections of limestone and other raw materials to produce lime and carbon dioxide, and then adding water to digest lime to produce lime milk (the main ingredient calcium dihydroxide) The calcium carbonate is precipitated by adding carbon dioxide lime milk, and is prepared by dehydration, drying and comminution. Or by sodium carbonate and calcium chloride Metathesis calcium carbonate precipitation, dehydration, drying and prepared.
The heavy calcium carbonate is called the heavy calcium. It is made by directly crushing natural calcite, limestone, chalk, Shell and so on.
It can be seen that light calcium is made by chemical methods, heavy calcium is mainly through mechanical crushing, grinding and separation methods. The true densities of light calcium and heavy calcium are 2.4ー2.6 G / cm 3 and 2.6ー2.9 G / cm 3 respectively They are classified industrially by sedimentation volume, which is the volume in which calcium carbonate per unit mass naturally settles and accumulates in Anhydrous Ethanol. In general, the sedimentation volume of light calcium is above 2.5 ml / G, while that of heavy calcium carbonate is 1.2 ~ 1.9 ml / g. The average diameter of the light calcium particles is 2-3 m, the average diameter is 1-3 m. However, due to the surface treatment, after the formation of light calcium, dehydration and drying, many particles tend to agglomerate together to form a grape-like globules Therefore, the quality requirement of light calcium in GB is only judged from 125 m and 45 m sieve residues, which does not reflect the true particle size and distribution directly.
3. Light calcium carbonate versus heavy calcium carbonate as a plastic filler:
As for the differences in their performance (without surface treatment) , if used as a filler in plastic processing, the plastic surface with light calcium is generally smoother, and the density will be lower; The flowability of the plastics is better, and the properties of the decalcified plastics with smaller particle size are also better.