Platey™ PCC Process

Platey™ PCC Process

The HouDa Paper case study and CPL’s proprietary Platey PCC™ process: high-value sub-micron rhombohedral and platy PCC from pulp mill lime and green liquor.

Case Study - HouDa Paper Co., Ltd Hezhou, Guangxi

HouDa Paper was built in the 1990’s with a PCC processing plant. The original design included the PCC plant because the plan was to never install a lime kiln due the large supply of lime from the surrounding marble mountains (Calcite).

Calcite mountains in the background of HouDa Paper Co. in the foreground (Guangxi, China)
Calcite mountains in the background of HouDa Paper Co. in the foreground (Guangxi, China)
Bagging operation at HouDa PCC plant (left), PCC process tankage (right)Bagging operation at HouDa PCC plant (left), PCC process tankage (right)
Bagging operation at HouDa PCC plant (left), PCC process tankage (right)

The PCC plant was not successful since the PCC morphology created was large scalenohedral (not sub-micron) morphology.

Low value large spindle shaped PCC morphology from typical pulp mill lime mud
Low value large spindle shaped PCC morphology from typical pulp mill lime mud

CPL Platey PCC™ Process

CPL has invented a proprietary process to create high-value sub-micron rhombohedral (e.g. surface treatment) and platy (e.g. internal opacity enhancer and brightener) for the paper industry. This process can be easily adapted to existing open loop pulp mills. The lime mud is therefore, commercial grade sub-micron PCC. In addition, platy PCC morphology can be used in many other industries.

SEM Shows evidence of high-grade PCC

CPL used actual lime and green liquor from an undisclosed pulp mill in China to create rhombohedral and platy morphology PCC. The SEM photographs below are actual samples from the modified recausticization process used in pulp mills.

Evidence of rhombohedral morphology from actual pulp mill lime and green liquor
Evidence of rhombohedral morphology from actual pulp mill lime and green liquor
Evidence of platy morphology from actual pulp mill lime and green liquor
Evidence of platy morphology from actual pulp mill lime and green liquor