Demonstration Pilot Plant for the Production of Precipitated Calcium Carbonate (PCC) from Steelmaking Slag and Carbon Dioxide

Demonstration pilot plant for the production of precipitated calcium carbonate (PCC) from steelmaking slag and Carbon dioxide

A. SAID^1,*,, S: ELONEVA¹ and M. JÄRVINEN¹

¹Department of Energy Technology, School of Engineering,

Aalto University, Espoo, Finland

*Corresponding author: arshe.said@aalto.fi, +358-50-571888, +358-41-523 1577.

Abstract

The ongoing research on production of precipitated calcium carbonate (PCC) from steelmaking slag at Aalto University, Finland has reached a decisive stage where we are constructing the first demonstration pilot plant in Finland for mineral carbonation. We have recently developed an indirect mineral carbonation method where aqueous solution of ammonium salt is used to selectively extract calcium from steelmaking slag, followed by precipitation of PCC by bubbling CO₂ through the produced solution. The aqueous solution of ammonium salt is thus regenerated and can then be re-used. The process is operated under ambient temperature and pressure. The final product, PCC is important paper filler and coating material for which global production has increased from 10Mt in 2004 to 14Mt in 2011. The pilot plant consists of three reactors (one for calcium extraction reactor and two carbonation reactors) each with a volume of 0.2 m³, solid and liquid separation equipments, reserve tanks plus  other process units (pumps, valves etc). The objective of this paper is to present the scale-up design, results and challenges from the pilot plant.

The work is a continuation of work presented by Eloneva et al. at ACEME10 in Turku, Finland, and is a part of efforts to scale-up this concept to industrial scale.