Keeping Your Cool

:: Wednesday, February 16, 2022 :: Posted By Emmanuel Laval

Imagine a dark and stormy summer night. It’s hot, and the local hospital is sitting at the center of a fierce storm. All at once, a lightning strike cuts off power to the building. Without cooling, patients and staff suffer and the hospital risks the loss of critical supplies and medications—even lives.

Fortunately, the hospital’s emergency plan includes redundant systems. Immediately, a backup generator kicks in. Although it hasn’t been used in months, the engine revs to life instantly—kept cool by its internal closed-loop cooling system.

The facilities managers behind these systems know that regular maintenance is critical to ensuring that smooth, automatic switchover. A backup generator isn’t much of a backup if it overheats and seizes. Heat exchange devices and systems using aqueous solutions often suffer from metal corrosion, sludge build up, and the gradual reduction of heat transfer capabilities.

Borates can help address those issues—extending the life of water-cooling systems and maintaining the integrity of their metal parts.

How do borates in water treatment benefit closed-loop cooling systems?

Borates aren’t typically the first additive that comes to mind when discussing water treatment chemicals. However, adding borates can help with corrosion inhibition, buffering, and water softening.

In addition to the cooling systems in generators and other engine types, many organizations rely on industrial closed-loop cooling systems to keep their central heating systems, cooling towers, and circulating water devices operating, including:

  • Wastewater treatment plants
  • Manufacturers
  • Hospitals
  • Industrial facilities
  • Nuclear and fossil-fuel based power plants
  • Food and beverage processing plants

Borates support water treatment systems

Borates protect closed-loop systems in three ways: Corrosion inhibition, buffering, and cleaning.


Aqueous solutions can cause corrosion on metals or alloys found in water treatment systems. Corrosion is an electrochemical event in which a destructive interaction occurs between a metallic surface and non-metallic environment. When this happens, the effectiveness of systems that transfer heat decreases significantly.

Borates are used for anodic passivation promoting the growth of a ferric oxide film on the metal’s surface. This film acts as a protective layer against oxygen that can cause metal to corrode.

Buffer and neutralizer of acidic materials

Borates excel at pH control and act as alkaline buffers—making them powerful cleaning agents.

And, since borates help maintain a consistent pH level, water in your system stays within a noncorrosive range. If the pH level of your water drops, bacteria can grow more easily—which can also reduce the ability of your system to transfer heat.

Acidic chemicals found in water treatment solutions can also damage metal surfaces. However, when borates are added to the solution, they work in conjunction with other inhibitors and reduce the amount of damage low pH chemicals can cause.

Cleaning (surfactant)

It’s widely known that borates are adept in metal-cleaning applications.

Borates have water-softening capabilities, which reduce deposits of insoluble minerals like calcium and magnesium. Over time, these can leave unwanted deposits in your system.

Use of borates in water treatment is expanding

Ever since the Electric Power Research Institute reported on the corrosion inhibiting effects of Optibor® boric acid in 1987, its use and methods of application have expanded.

For instance, nuclear power plants are using boric acid to control corrosion in steam generators and in auxiliary closed-loop cooling systems, mainly because it will not produce significant amounts of secondary radiation.

Curious about how you might benefit from borates in water treatment or need help choosing the correct borate products? Contact our technical experts.




U.S. Borax, part of Rio Tinto, is a global leader in the supply and science of borates—naturally-occurring minerals containing boron and other elements. We are 1,000 people serving 650 customers with more than 1,800 delivery locations globally. We supply around 30% of the world’s need for refined borates from our world-class mine in Boron, California, about 100 miles northeast of Los Angeles.  Learn more about Rio Tinto.

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