Calcium Carbonate Grinding Project for Paper Coating (6 TPH, 350 Mesh)​

The project also exemplifies industry collaboration: the smelter shares real-time flux performance data with the grinding plant, allowing for adjustments to particle size or composition—ensuring continuous improvement in smelting efficiency.​
 

This fluorite grinding project underscores the critical role of mineral processing in metallurgy, where high-quality flux can significantly improve metal recovery and reduce energy consumption, supporting sustainable industrial practices.​

 

Calcium carbonate (CaCO₃) is widely used in the paper industry as a coating pigment—improving paper’s whiteness, smoothness, and printability. This article explores a calcium carbonate grinding project in Quebec, Canada—a region with abundant high-purity limestone (the raw material for calcium carbonate)—producing 350-mesh calcium carbonate powder at 6 TPH for a North American paper mill. The project focuses on achieving ultra-high whiteness and narrow particle size distribution, critical for high-quality coated paper (e.g., magazine paper, catalogs).​

Project Background and Paper Industry Requirements​
 

Coated paper requires a smooth, white surface to ensure sharp printing and vibrant colors. Calcium carbonate is the preferred coating pigment (over clay) because: (1) It has higher whiteness (90-95% vs. 80-85% for clay); (2) It is cheaper (30% lower cost than clay); (3) It improves paper’s opacity (reducing ink usage). The paper mill specified 350-mesh (42 μm) fineness with a narrow particle size distribution (d10 ≥35 μm, d50 40-44 μm, d90 ≤50 μm) because: (1) Uniform particles create a smooth coating (coarser particles cause roughness, finer particles increase viscosity);

(2) It ensures good coverage (hiding power) with minimal pigment dosage (15-20 g/m²). The 6 TPH capacity matches the mill’s daily coating demand (144 tons per day, enough for 7.2 million square meters of coated paper).​