ABSTRACT

A new process concept for removal of potassium, chlorine and sulphur, and simultaneous recovery of sodium was developed. The concept comprises simplified stripping of hydrogen sulphide from green liquor (GLSS), purging of sulphur in elemental form by a liquid redox process, and crystallization of ESP dust together with stripped green liquor. The process allows for simultaneous removal of the mentioned elements with smaller losses of sodium than in earlier ESP dust based processes. The balances of the elements can be controlled independently of each other. The process has been tested in a pilot plant.

Keywords: chlorine, electrostatic precipitator dust, potassium, removal, sulphur.

*Authors references:

1. Valmet Corporation – Finland

Valmet Celulose, Papel e Energia Ltda. – CEP 83704-530, Araucária, PR, Brasil

2. Oy Sirra Ab – Bondarbyvägen 177, 02420 Kyrkslätt, Finland

Corresponding author: Välimäki E.J. - E-mail: erkki.valimaki@valmet.com