Method for analysis of green liquor with green liquor sludge

Purpose

With the green liquor sludge that settles or is filtered out during the sludge separation, many metal compounds disappear from the recycling process, which otherwise cause a lot of problems in the lime cycle. The green liquor must be sufficiently clean and free of green liquor sludge for the subsequent causticization.

When analyzing metals in green liquor with green liquor sludge, it is important to know how the customer wants the samples analyzed. What we need to know before analysis is whether the sample should be analyzed on a shaken sample (with green liquor sludge) or whether it is the metals in the green liquor (sedimented sample) that are of interest. When analyzing green liquor, the sample is peroxide treated and analyzed using standard addition technology with ICP-OES.

The sludge is separated from the green liquor and then the fractions are treated separately. The treated fractions are then pooled and analyzed by ICP-OES. The result shows the constituent metals and their contents.

It is important to keep track of not least aluminum and magnesium in the lye cycle. Therefore, the sludge separation must work and not let sludge through with the green liquor. With our analyzes of green liquor and sludge, it is easy to keep track of the process-disrupting metals and solve problems that arise later in the process but which have their cause in the separation of green liquor sludge.

With an increasing degree of closure in the pulp process, the levels of process-disrupting metals increase and thus the risk of problems. For example, increments can form in pipes and heat exchangers that reduce their efficiency and filters can also be adversely affected.

Method

ICP-OES

Deliveries

Report