WaterCare Treatment for Spent Process Coolants

December 30, 2014

In general industry, the process manufacturing and machining of any metal substrate (mild steel, copper, brass, and aluminum) requires coolants to protect tooling life, as well as create the proper conditions for the work in process.

The coolants eventually become “spent” and need to be replaced. In most cases today, semi-synthetic coolants are used. 

WaterCare provides the perfect solution to split waste oil from the total solution water, thereby minimizing the waste disposal and providing a method to discharge the water portion and reclaim the waste oil for recycle. 

The cost savings by treatment versus disposal of the spent coolants is significant. 

Case History Example:

An integrated machining operation currently ships 250,000 – 300,000 liters of semi synthetic spent coolant offsite for disposal due to oil and grease contamination. The disposal costs for offsite disposal are $125,000.00 – $135,000.00 USD per year. 

Our objective is to develop a wastewater treatment program to effectively split the oil from the water so that the water can be discharged via the sewer system.

Recommended WaterCare Treatment Method

Per 300,000 liters (79,260 US gallons) of spent coolant treated

  1. Starting pH was 9.6
  2. While mixing, add concentrated sulfuric acid (66 degree Baume`) to adjust the pH down to 2.  Based on laboratory testing, it will take approximately 7,500 liters of sulfuric acid to pH adjust 300,000 liters of spent coolant.
  3. Add OMEGA CP-1162 cationic polymer to achieve a concentration of 2,000 ppm. This is equal to 1,322 pounds (598 Kg) or 158 US gallons (589 liters) of neat product.
  4. Allow treated spent coolant to mix for approximately 15 minutes and turn mixer off. 
  5. Let mixture sit for 1-2 hours to allow oil layer to split and rise to the surface. Decant demulsified water layer to the sewer system. 
  6. Send oil layer to an offsite disposal facility for reclaim processing.    

This treatment method resulted in:

  • Water layer of 40% by volume. 
  • Oil layer of 60% by volume.
  • The water layer had very good clarity suitable for discharge.

Untreated Spent Coolant (left beaker)

Coolant Treated with the WaterCare Program (right beaker)

Need help with your specific application? Take the time to complete our WaterCare Survey Form and our experts will review and advise on the best approach moving forward with WaterCare as your Partner.

Posted in News By

Coventya WaterCare

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