Integrated Production Line of Calcium Hydroxide from Limestone to Putty Powder

The calcium hydroxide production line facilitates the transition from limestone to putty powder. With the increasing demand for putty powder and heightened requirements for product quality and environmental protection, the shortcomings of traditional production models have become more

pronounced: high costs and significant pressure in energy conservation and emissions reduction. The Cronus calcium hydroxide production line rigorously controls key processes such as calcination, digestion, drying, and modification, laying a solid foundation for producing stable and high-quality putty powder.

Digestion: A countercurrent digestion system is employed with a lime-to-water ratio of 10:7. The digestion time is extended to 25 minutes, resulting in finer calcium hydroxide particles with a median particle size (D50) ≤15μm, thereby enhancing the performance of the putty powder. A 200-mesh vibrating screen is used to eliminate undigested particles and other impurities, ensuring the purity of calcium hydroxide.

Drying: The drying process utilizes low-temperature drying techniques with temperatures controlled below 120°C to prevent carbonation of calcium hydroxide.

Modification: An addition of 0.5% stearic acid is implemented for surface coating modification, imparting hydrophobic properties to calcium hydroxide which extends the shelf life of putty powder while improving its application performance.

Common Issues in Calcium Hydroxide Production Line Poor grindability

This issue primarily arises from overly coarse particle sizes of calcium hydroxide as well as an excessive proportion of hydrated lime in formulations. To optimize product performance, measures can be taken to enhance the fineness level of calcium hydroxide up to 600 mesh for achieving finer particles that improve smoothness and grindability. Additionally, appropriately reducing hydrated lime’s proportion in formulations down to 8% will mitigate its negative impact on product grindability. Through these improvements, we anticipate significantly enhanced grinding performance that meets market demands.

Yellowing products: It is inevitable that raw limestone contains certain amounts of iron-containing impurities which may undergo oxidation during subsequent processing stages affecting color and quality. To effectively address this issue, we have incorporated a crucial step—magnetic separation—to remove iron impurities during production processes. This allows us precise removal of ferrous contaminants from limestone while strictly controlling iron oxide (Fe₂O₃) content below 0.05%, thus ensuring that produced materials like putty powder do not exhibit yellowing phenomena.

Conclusion

The Cronus calcium hydroxide production line addresses issues related to high energy consumption and poor uniformity associated with traditional manufacturing through countercurrent digestion, low-temperature drying, surface modification along with stringent impurity control measures. As a result，the comprehensive cost associated with putty powder has decreased by approximately 25%, enabling autonomous control over raw material sourcing while gaining advantages in cost management，environmental sustainability，and product quality