1. Different source
Calcium carbonate light is chemically synthesized , also known as precipitated calcium carbonate. It is produced by calcining limestone raw materials to produce lime and carbon dioxide, generating calcium carbonate precipitates, which are dehydrated, dried, and crushed, or by the double decomposition reaction of sodium carbonate and calcium chloride. Heavy calcium carbonate is produced by directly crushing natural calcite, marble, shells, etc. using mechanical methods.
2. Different densities
The most obvious difference between heavy calcium and light calcium lies in the different stacking densities of the products. Heavy calcium products have a higher stacking density, generally ranging from 0.8 to 1.3 g/cm3; The stacking density of light calcium products is relatively small, mostly ranging from 0.5 to 0.7g/cm3;
3. Different whiteness
Due to the relatively high amount of impurities in calcium carbonate heavy products, the whiteness of the products is generally lower than that of light calcium carbonate. Light calcium carbonate products, due to their chemical synthesis, remove many impurities and have high purity, resulting in a higher whiteness.
4 Different flavors
Calcium carbonate light generally has a higher whiteness and purity due to the removal of many impurities after limestone calcination. However, some domestically produced light calcium may have a residual lime flavor due to incomplete calcium oxide reaction. If used in the food industry, such as filling biscuits, it may have a choking taste, while heavy calcium does not.
5 particles with different shapes
When viewed under a high-power microscope, heavy calcium products usually have irregular particle shapes such as cubes, prisms, and rectangles due to the use of mechanical crushing and grading. The microstructure of calcium carbonate varies for different processing methods of heavy calcium.
The particles of ordinary light calcium are relatively regular and usually form a spindle shape when fully dispersed, as shown in Figure 2. For light calcium carbonate, the particle shape of the synthesized product can be artificially controlled.
6 different crystal forms
For calcium carbonate heavy from different regions, it has a fixed crystal shape, and crushing and refining will not change the crystal shape. Generally, calcite heavy calcium is hexagonal crystal form, while marble heavy calcium is cubic crystal form. For light, in the specific carbonization preparation process, three crystal forms appear simultaneously in different proportions. To obtain a single and pure crystal form, the molding process needs to be controlled.
7 Different prices
The processing of heavy calcium carbonate is mainly achieved through mechanical crushing and grinding methods; The production of lightweight calcium carbonate is achieved through chemical reaction precipitation, which is much more complex in process and requires stricter requirements than the former. Therefore, heavy calcium carbonate with the same particle size is cheaper than light.
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