How To Recharge DI Resin

How to Recharge DI resin by David Sanders: Before starting, I would like to mention that some information available on the web would have you believe that a full body hazmat suit is needed to safely use the two chemicals necessary to recharge de-ionizing resin (DI). If common sense is used, you'll be safe. Most homes have had these chemicals to some extent in the cupboards below the sink. Acids like muriatic or hydrochloride are used to remove scale from showers and toilets. Lye has been used to clear drains and cut grease for years. Your grandparent may have used lye soap also. The muriatic acid is stronger than packaged bathroom cleaners. I did get small amounts on my skin and it felt like a mosquito bite. When I realized that it was not, I washed my hands and all was good. Some chlorine gas comes out of the bottle and when it is mixed, so don't sniff the bottle. I mention this because those without common sense should not attempt this project.

A little more than a year ago I was poking around on the web, I found a few companies that regenerated DI resin. I began to look for a way to do it myself. I ran across an article on reefs.org that explained what I was looking for. Although their finished result was the same as what we do, their canister had a drain. The drain allows the resin to be regenerated in the canisters. Most canisters on the market do not have this drain, so another solution was needed.

First gather up the products needed. The chemicals can be found at Lowe's and the tools at Wal-Mart. The lye is found at Lowe's in the pluming section. It is used for clearing drains and made by a company called Roebic, and is 100% sodium hydroxide (caustic soda), listed as lye on the back of the bottle. The muriatic acid is found in the paint department. The mixing bottles must hold 16 oz. of fluid. I now use an old lye bottle; it is sturdy and holds up to the heat. The two containers used to separate the resins came from Wal-Mart and hold 64 oz. each. I also needed a large colander, window sheer as a filter, a stir stick, 5 oz. measuring cup (large shot glass), two 32 oz. tumblers, and two 5 gallon buckets. When I first did this process I used a turkey baster and coffee filters. The turkey baster was used to separate the resin, and the coffee filters where used to filter the resin. I will show both processes. Obviously, you need a decent amount of used DI resin. During the recharging process, a little bit of resin will be lost, so it is best to have a few cartridges of resin saved up. Read the full process with pictures here.

Use these instructions at your own risk.   The chemicals used in this procedure are very dangerous and must be used with a great deal of caution.  It is recommended that you wear protective gloves and goggles when performing the following procedure.

• 12 ounce can of Red Devil Pure Lye (good for 2-3 recharges) ~$2
• One gallon Muriatic acid (good for about 20 recharges) ~$3
• Turkey baster
• Plastic container, 1/2 gallon or so... a deep bowl will work
• Plastic bottle - needs to be fairly tough.  Use one that holds atleast  12 fluid ounces, marked measurements are a bonus
• Measuring cup, 24 fluid ounce or larger
• Glass or plastic stirring rod
• About 5 gallons DI water (tap water will suffice) for rinsing resins
• 5 gallon bucket
• Activated filter carbon
• Rubber gloves/goggles, just in case

How to Clean DI Resin: Deionized resin, or DI resin, is an essential component in the deionization process. The resin is able to bind to and filter out mineral salts, including sodium and copper, thus cleaning water. The filtration process is used anywhere people require high-purity water, including laboratories and fish aquariums. With use, the DI resin will eventually become exhausted and dirty. However, you can recharge and clean your DI resin with chemical baths.

• Pour 11 oz. of reverse-osmosis deionized water into a 16 oz. glass bottle. Add 3 oz. of lye. Make sure to pour the water in the bottle first, before the lye, to avoid unwanted splashing of the chemical. Seal the bottle with its lid.
• Place the glass bottle holding the solution into a bucket of ice-cold water. Gently shake the glass bottle and its solution to ensure that the lye doesn't settle on the bottom. Mixing lye and water creates heat, so this step will ensure it's cool enough to work with. Leave the bottle in the ice water for 15 minutes.
• Put the dirty DI resin you wish to clean in a 64 oz. glass container. Pour the cooled lye solution into this container.
• Stir the resin and the lye solution together using a plastic or wooden stick. The lye should be evenly dispersed among the resin. Let the mixture sit for five minutes. The DI resins will separate, with the cleaned and charged resins floating to the top. The completely exhausted and dirty resin, which can no longer be used in this state, will sink to the bottom.
• Collect the cleaned and charged resin from the surface of the solution using a turkey baster.
• Put the cleaned resin into a coffee filter. Run RO/DI water over the resin to completely remove the lye solution. It is now ready for use. Store it in a secure glass container and put it aside.
• Separate the exhausted resin from the lye solution using a turkey baster. Place it in a coffee filter and thoroughly wash off any lye solution. Place the cleaned resin in a 64 oz. glass bottle.
• Mix 6 oz. of muriatic acid with 6 ounce of RO/DI water in a 16 oz. glass bottle.
• Pour the acid solution into the 64 oz. bottle holding the exhausted resin. Mix it with a stirring stick. Let the solution sit for one hour. The color of the DI resin should change to purple, meaning that it's recharged and clean.
• Collect the newly-cleaned DI resin from the bottle. Wash the resin with RO/DI water in a coffee filter to ensure you remove all of the acid solution. This resin is now clean and ready for use. Store it in a secure container until you're ready to use it.