Pumping Black Liquor - What is it and how Eddy Pump can help?

The purpose of this article is to provide an understanding of the process of creating black liquor. Learn what it is, how it's made, and how the EDDY Pump can excel production.
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Every day, kraft paper mills turn wood into wood pulp. This wood pulp can go on to be used to create paper products of all kinds. While this process goes unnoticed by many, for those working in the industry, the kraft process is a complex and integral part of the work that is done.

Much of what takes place during this process requires an in-depth knowledge of how to process materials and ensure the right equipment and tools are on hand to keep the mill operating smoothly, safely, and efficiently.

One such step in the kraft process that requires careful attention is in the pumping and transfer of black liquor and black liquor soap. And it all begins with understanding what these byproducts are and the unique pumping challenges they present.

This Article Includes

  • What is Black Liquor Soap?
  • The EDDY Pump – Ideally Suited for Black Liquor Soap Applications
What is Black Liquor and Black Liquor Soap

What is Black Liquor and Black Liquor Soap?

During the kraft process, the raw wood is converted into wood pulp. This is the stuff that will later be turned into paper products. In the process of making wood pulp, a byproduct is created called black liquor. According to data, approximately 7 tonnes of black liquor is produced every time a single tonne of pulp is created.

These numbers make it easy to see how much black liquor needs to be pumped during the daily operation of a kraft paper mill. Once upon a time, this black liquor was simply dumped into bodies of water. Today, however, black liquor is actually used as an energy source for mills.

From black liquor, another byproduct is derived — black liquor soap. This soap is skimmed from the black liquor as the black liquor settles. The resulting black liquor soap is a slurry that is abrasive, corrosive, and varies greatly in viscosity. This is the target material we can help you pump.

Also, see our article on Paper and Pulp pumping: https://eddypump.com/applications/paper-pulp-pump-applications/

What is Black Liquor and Black Liquor Soap

What is Black Liquor Soap Used For?

Black liquor itself is converted into an energy source, but black liquor soap goes on to be used to create tall oil. This tall oil is then used in the production of coatings, paints, varnishes, lubricants, soaps, and more.

What is Black Liquor and Black Liquor Soap

Common Difficulties When Pumping Black Liquor Soap

Black liquor soap must be transferred during the recovery process, as well as transferred during the production of tall oil.

Throughout the process of transferring black liquor soap, there are a few challenges that make the average pump incapable of handling the product.

  1.   The viscosity of black liquor soap is not constant. Temperature changes and other variables can cause the viscosity to shift drastically. This lack of consistent viscosity plays a big role in the selection of a pump for the transfer of the black liquor soap. Most pumps cannot handle this variance, leading to constant adjustments.
  2.   Due to the strain put on the pump, high levels of maintenance are usually required — a costly and time-consuming solution.
  3.   Black liquor soap is highly abrasive, which can degrade the average pump. In order to transfer this abrasive material, a highly durable pump capable of dealing with abrasives is necessary.
What is Black Liquor and Black Liquor Soap

The EDDY Pump – Ideally Suited for Pump Black Liquor Soap Applications

When transferring black liquor soap, it is important to choose a pump that is suited for this application. The EDDY Slurry Pump is considered one of the premier high-viscosity pumps and is designed to handle abrasive materials, such as black liquor soap.

Over three decades of expertise has gone into the design of this pump, with a focus on pumping even the most difficult of materials.

Part of the design of the EDDY Slurry Pump is a non-clogging pathway that has been enlarged, paired with a recessed rotor for moving large amounts of black liquor soap through the pump without issue. The unique design of the recessed rotor and the method by which the pump displaces fluid creates an Eddy Current. This current of fluid results in a vortex, extending down the inlet of the pump. The end result is that the pump’s suction is strong enough to pull even solid particles upwards.

This ability to pump concentrated solids is a notable feature of the EDDY Slurry Pump. This makes it a great fit for black liquor soap applications as the pump is capable of moving viscous materials with as much as 30-70% solids by volume.

Other benefits of the pump are that it requires low maintenance, has no critical tolerances, and allows for minimal downtime. This 100% American-made pump is the perfect addition for kraft paper mills.

For more information about using the EDDY Pump for black liquor soap applications, go to https://eddypump.com/ or contact our team.


The EDDY Pump Corporation

The EDDY Pump Corporation is a leading provider of unique slurry and dredge pumps, and manufactures products that provide superior value versus other pump types.  The pump is not a centrifugal, vortex, or positive displacement pump, but rather a pump harnessing the fluid dynamics of an eddy current. This enables the EDDY pump to outperform conventional pumps in applications that involve high viscosity, large weight of solids and particulates, high specific gravity, corrosive and abrasive material, work well in applications that are susceptible to clogging, and do it in an environmentally friendly manner. 

EDDY Pump Product Categories

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  • Dredging Equipment
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    • Cable Deployed Dredge
    • Hydraulic Power Units (HPU)

If you are pumping slurry, brines, high solids, extremely viscous material, paste, high abrasives (sand & gravel), and material filled with solids, then you found the best-suited pump for the job.  Go to:  https://eddypump.com/  or Call Us!

Mining, Fly Ash, Coal Ash, Oil, Fracking, Gas, Wastewater, Pulp and Paper, Chemical, Energy, Water Municipalities, Irrigation, and Dredging Companies.  For Access to Complete Product Line Go to: https://eddypump.com/products/ 

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