Sulphate Resisting Cement Manufacturing
Sulphate resisting cement (SRC cement) is a type of hydraulic binding material with resistance to sulfate ion. It is manufactured by fine grinding of Portland cement clinker, an appropriate amount of gypsum, and blast furnace slag. Compared with other Portland cement, it features high sulfate resistance, strong frost resistance, and low hydration heat.
Sulphate resisting cement has low tricalcium aluminate and tetracalcium aluminoferrite content and high tricalcium silicate content. This structure reduces the formation of sulfate salt thus improves the performance of concrete stones for sulfate attack and enhance their durability in most aggressive environments. It is suitable for seaport engineering, water conservancy engineering, and underground construction, which are easily affected by sulfate corrosion, freeze-thaw and, dry-wet alternation.
Properties of Sulphate Resisting Cement
Sulphate resisting Portland cement can be divided into moderate sulphate resisting cement and high sulphate resisting cement. Their strength grades are 32.5, 42.5, and 52.5.
Moderate sulphate resisting cement (code P-MSR) can resist the corrosion of sulfate ions with a medium concentration. The content of tricalcium silicate does not exceed 55.0%, and the tricalcium aluminate is no more than 5.0%.
High sulphate resisting cement (code P-HSR) can resist the corrosion of sulfate ions with a high concentration. The content of tricalcium silicate and tricalcium aluminate is less than 50% and 3%, respectively.
|Compressive strength||Ignition loss||Free lime content||Magnesium oxide content||Undissolved substance content||Specific surface area||Initial setting time||Final setting time|
|10Mpa at 3 days, 16Mpa at 7 days, and 33Mpa at 28 days||≤3%||≤1.0%||≤5%||≤1.5%||≥280m2/kg||≥45min||≤10h|
Sulphate Resisting Cement Uses
Concrete prepared from sulfate resistant cement has a strong resistance to pure sulfate whose concentration of sulphate ion is less than 2500mg/L. It is ideal for concrete engineering in contact with acidic soil, groundwater, seawater, etc. The use of SRC cement is recommended for the following applications:
Sulphate Resisting Cement Features
AGICO offers sulphate resisting cement plants from 50-10000 TPD. Please feel free to contact us!
Sulphate Resisting Cement Manufacturing Process
Raw materials needed in the production of sulfate resistant cement are basically the same as ordinary Portland cement, mainly including calcareous materials, clayey materials, and ferriferous corrective materials. However, their mineral composition is very different from the ordinary Portland cement.
- The hydration product of C3A is the component that most susceptible to corrosion in cement. As the corrosion resistance of C4AF is stronger than C3A, it partially replaces C3A in sulfate resistant cement to improve the non-corrodibility.
- CH produced in the hydration process of C3S is another factor leading to corrosion. Therefore, appropriately reducing the content of C3S and correspondingly increasing C2S which has better performance is also an effective measure to improve the corrosion resistance of sulfate resistant cement.
The manufacturing process of sulphate resisting cement is almost the same as ordinary Portland cement. It can be divided into:
Raw Material Preparation
Limestone, clay, and other raw materials should be first crushed into raw mill feed size by cement crushers. After that, they are stored in a pre-homogenization storage yard and then be mixed in proportion and fed to cement raw mill for subsequent fine grinding. The fine ground raw meal will be stored in storage bins waiting for calcination.
In the calcination process, cement raw meals will first enter the preheater and precalciner to complete the preheating and partial carbonate decomposition. Then they are sent into the cement kiln for formal calcination until the clinker is formed. After that, the hot clinker will be cooled to a normal temperature in a cement cooler placed behind the kiln.
Cement clinker is usually mixed with gypsum and other admixtures for a specific property before sent into the cement mill. In a cement mill, they are finely ground until reach the fineness required for cement products. After grinding, cement powder is stored in cement silos and then packed in bags by cement packing machines.