Date of Defense
Date of Graduation
Chemical and Paper Engineering
Imerys is a chemical production and processing company that produces and supplies mineral-based chemical solutions for industry to a wide variety of sectors. One of these products is Precipitated Calcium Carbonate (PCC), which is used in several industries including pulp and paper, pharmaceutical, food, and others. The location we are working with in Asheville, NC solely sells to the pulp and paper industry, both onsite and offsite.
A PCC slurry product being produced at 20% solids is the focus of our project. This slurry is sold offsite and shipped in trucks to its customers. The objective of our project is to increase the percentage solids of the slurry being sold offsite to 30%, with the goal of saving on freight and increasing profit margin. This will involve allowing the lower solids PCC to settle, before removing the water that has settled to the top via a pipe that has been installed in the side of the tank at a designated height. This water can then be pumped back into the process or sewered.
An analysis of the process and market was done as a preliminary step. Material and Energy balances were created for the system to determine requirements to produce a product at 30% solids. Lab testing of samples was done to investigate the properties of the slurry at 20% and 30% solids and to evaluate the settling behavior of a PCC slurry. A proposed design was then put forth to reach the target solids for offsite sales. Finally, an economic analysis of the project as a whole was done to determine the feasibility. This resulted in an IRR of 74.47 and a PBP of 1.44 months. These values were found using a 5% increase to the current price of PCC.
Our conclusions for this project were that a 30% solids PCC slurry is still a useable product for the customer and the higher viscosity should not be an issue to store or ship. We also concluded that the capital investment needed to make dewatering to higher solids is worthwhile due to the significant cost savings through decreased shipping costs and increased offsite sales as well as a 5% increase in selling price.
Edmonds, Rowan, "Precipitated Calcium Carbonate – Low Cost Means to Increase Solids" (2023). Honors Theses. 3684.
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Available for download on Friday, December 08, 2023