Econotech manufactures for sale, a Reburned Lime Analyzer which can be used to optimize lime kiln operation. This analyzer can be used to improve lime quality and save kiln energy costs.  Many pulp mills and lime producers use this analyzer because of its ease in operator training and operation.

Econotech developed the Reburned Lime Analyzer for rapid and reliable analysis of residual carbonate (CaCO3). Since 1979, many satisfied customers have used our instrument to control their lime reburning operations, mainly kraft mills, but also lime and cement manufacturers. Users of the Econotech Reburned Lime Analyzer have quickly realized the many benefits of using the residual carbonate test as a control parameter:

• Substantial fuel savings
• Less overburning or underburning
• Improved recausticizing operation
• Improved white liquor quality
• Improved causticizing efficiency
• Better control before and after the kiln

CONTACT
Ralph Abley  <firstname>@econotech.com

OPTIMIZED LIME REBURNING

The most important criteria for efficient operation of the lime kiln are: minimum energy consumption, reburned lime with high availability and high reactivity. Determination of unreacted residual carbonate is the only effective test for controlling the degree of lime burning. If the lime availability test is used instead, without knowledge of the concentration of inerts present in the lime, this gives a false indication of the degree of burning with the consequent penalties of high energy consumption and poor lime quality.

ENERGY SAVINGS

Today's ever-increasing pressures to reduce manufacturing costs are forcing all operating units to eliminate wasteful uses of energy. Both underburning and overburning of lime are energy inefficient. Only the residual CaCO3 test provides a direct measure of the degree of burning, and a proper control of the amount of fuel fed to the lime kiln.

CaCO3 + Heat CaO + CO2

IMPROVED LIME QUALITY

Overburned and underburned lime can both negatively impact the slaking and recausticizing operations of a kraft mill. Underburned lime produces a deadload that results in increased energy consumption and reduced equipment efficiency. Overburned lime, on the other hand, has poor slaking and recausticizing properties. Experience has proven that targeting for residual carbonate between 1-2% results in good lime reactivity, near maximum lime availability and little overburning.

CaO + H2O Ca(OH)2
Na2CO3 + Ca(OH)2 2NaOH + CaCO3

RESIDUAL CARBONATE ANALYSIS

The Econotech Reburned Lime Analyzer is designed for ease of operation, simplicity and portability. The instrument measures the volume of CO2 evolved from the reaction of reburned lime with an acid. The operator determines percent CaCO3 from the volume of CO2 using a chart provided.

CaCO3 + 2HCl CaCl2 + H2O + CO2 .