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Aries Helps Recycled Paper Mill Control Scale And Deposits

A recycled board mill took substantial downtime in its wastewater treatment plant to clean DAF recycle pumps due to scale and deposits. The mill has Dissolved Air Floatation (DAF) clarifiers in its wastewater treatment plant. The DAF clarifiers utilize clarified water to produce water with fine air bubbles to float solids. The clarified water is pumped through recycle pumps that would lose performance over time due to deposits. Substantial downtime was required to periodically clean the pumps.

Aries Chemical was asked to provide a solution to reduce the recycle pumps’ downtime. Aries surveyed the paper mill’s existing raw water treatment system and performed deposit and water analysis to understand what was causing the deposit. The deposit analysis showed that the primary component of the scale / deposit was calcium carbonate.

The scale / deposit was 65 % calcium carbonate while the clarified wastewater being recycled had a calcium hardness of 2,330 mg/l as CaCO³ at a 4,090 micromhos conductivity. Calcium carbonate scale is a common problem in water that contain high levels of hardness. The calcium carbonate source was most likely from the recycled paper that the mill used as a raw fiber source. Calcium carbonate is an additive that is used in a variety of paper mills.

Based upon the laboratory analysis Aries developed a blended scale and deposit inhibitor for this application: Aries 2958. Aries 2958 is designed to inhibit calcium carbonate scale formation in high hardness water. Aries 2958 is being fed into the clarified water ahead of the recycle pumps to minimize and control scale and deposits. The Aries 2958 program has been very successful reducing the down time to clean the recycle pump from every 4 weeks to more than 8 weeks.

For further information on Aries’s solutions for the paper and pulp industry, particularly when it comes to controlling scale and deposits, contact your Aries Chemical Representative or the Beaver Falls office at (315) 346-1489. Also view a printable version of this Aries Helps Recycled Paper Mill Control Scale And Deposits case study.