Neutralization is a complex process. Neutralization whether it is fed in in a continuous process or the neutralization of tanks in a batch process doesn’t always go as planned.
At a powder coater:
Our customer was frustrated. They could never adjust the automatic feed system that was supposed to prevent them from discharging water that was too acidic from going too alkaline with too high of a pH. They were getting continual discharge violations.
At a shelving manufacturer:
We were neutralizing the washer after an acidic clean-out and we were approaching the pH we needed for discharge. A few more gallons of neutralizer and we overshot our discharge point and a brown precipitate formed and deposited all over the washer.
Chemicals to neutralize acidic materials are often needed in industrial applications. Acid pickling baths, phosphating solutions, and clean-out materials often need to be neutralized before use, transport or disposal. Oftentimes it is difficult to reach the desired alkalinity/acidity pH level.
There is a better way.
Most neutralizing materials are built on hydroxides. A solution of sodium hydroxide has a very high pH and no buffering action so it is easy to overshoot a setpoint.
The best neutralizers are buffered. Buffering is the property of a chemical to resist a change in pH. If a chemical is well buffered it will not increase or decrease pH very quickly when it is neutralized. Some chemicals will change pH very slowly when neutralized and then change very quickly when you are near the set point.
The solution is to use a milder and buffered neutralizing material so that the neutralizer provides the buffering to change to pH slowly and with more control. It is much easier to reach a desired setpoint using a well buffered neutralizer. It prevents “see-sawing” back and forth over the desired pH
Excessive sludge is often caused when a neutralizing product does not mix in effectively of when the pH raises very quickly and the solution is “shocked” and precipitates metals.
In addition, safer less alkaline neutralizing options are available. Some are very low hazard materials. These can be handled with less danger.
We have developed several products for neutralization of acidic materials.
NEUTRALIZER UP-1 – A strong, unbuffered hydroxide-based neutralizer good when a large pH change is required and economy is an issue. Good for pickling tanks of sulfuric or hydrochloric based acids.
NEUTRALIZER UP-2 – A less alkaline neutralizer that gives you more control over the neutralization process. Good for use with acid cleaning tanks.
NEUTRALIZER UP-3 – A low cost carbonate-based neutralizer. Excellent for continuous feed to neutralize acidic solution being discharged to the drain. For example, rinse over flows or high-pressure iron phosphates or acidic cleaners.
NEUTRALIZER UP-4 – A highly concentrated carbonate-based neutralizer. Excellent for continuous feed to neutralize acid solutions being discharged to a drain. For example, rinse over flows or high-pressure iron phosphates or acidic cleaners.
NEUTRALIZER UP-5 – A safe low hazard bicarbonate-based neutralizer. Cannot raise a solution over a pH of 8.5. Used in specialty conditions like continuous unregulated feeds of low acid discharge. Can be useful in some over rinse discharges.
It is also a cost-effective idea to use an unbuffered neutralizer to do the bulk of your pH neutralization and use a buffered neutralizer when you near your endpoint.
Custom Designed Chemicals can custom make the chemicals you need. It is often effective to use an unbuffered neutralizer to change the pH from extremely low values and use a milder neutralizer to change the pH as it nears it desired point. We have also found that a custom blended neutralizer utilizing buffered and unbuffered components is effective in many conditions.
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