Case Study: Bolts Beat Welds In Erection Time And Labor

A precipitated calcium carbonate producer switches from welded to bolted tanks.

Specialty Minerals, a subsidiary of Minerals Technology, is headquartered in Bethlehem, Pa. It produces precipitated calcium carbonate (PCC) at 42 satellite operations worldwide. PCC, a synthetic form of calcium carbonate, gives paper brightness as well as opacity and can replace wood pulp or more expensive mineral fillers. Specialty Minerals uses bolted silos for raw lime storage and bolted tanks for PCC storage.

In the mid-1980s, the mineral producer found the best way to supply PCC to the paper industry was to set up satellite plants adjacent to the paper mills. This proximity gives mills ready access to precise, consistent amounts of PCC and reduces costs for both parties.

A satellite plant has a symbiotic relationship with the mill it serves. Typically the plant receives water and electricity from the mill and pipes wastewater back to the mill for treatment. The plant also gets a raw material, carbon dioxide, from the mill.