ION EXCHANGE RESIN

Pretreatment, Regeneration and Packing of ion exchange resin

Pretreatment, Regeneration and Packing of ion exchange resin.

I. Pretreatment and regeneration of new ion exchange for two beds demineralization systems.

1. Fill the specific ion exchange resin into the specific column to the designed height.

2. Backwash: backwash the resin, Be sure the expansion rate to reach 80% and keep it for ~ 20minutes.

3. Rinse: adjust the flow rate to 20-25m/hr. Rinse the ion exchange resin for about 30 min till the effluent clear.

4. Regeneration: regenerate the ion exchange resin as usual, only use 1.5-2.0 times of the normal amount of acid or soda when regenerating the resin at the first time.

II. Pretreatment and regeneration of MB ion exchange resin.

1. Pretreatment of MB ion exchange resin

a. Fill the ion exchange resin into the column according to the designed height (the height should be decided by the regenerated forms of the ion exchange resin).

b. Let HCl (3-3.5%) flow through the resin from the bottom inlet at the flow rate of 3-5m/h, and discharge the HCL from the top, Stop entering more HCL into the column once acid is detected from the top effluent, keep the ion exchange resin marinated in the acid for about 2 hours, and then rinse the ion exchange resin from bottom to top with pure water till neutral PH is reached.

c. Let HCl (3-3.5%) flow through the resin from the top inlet at the flow rate of 3-5m/h, and discharge the soda from the bottom, Stop entering more NaOH into the column once soda is detected from the bottom effluent, keep the ion exchange resin marinated in the soda for about 2 hours, and then rinse the ion exchange resin from bottom to top with pure water till neutral PH is reached.

2. Regeneration of MB ion exchange resin

Before beginning the following operation, make sure that the cation and anion MB resin are separated well and the heights of the resins are correct.

a. Tryout: enter pure water from the upper inlet and the bottom inlet at the same time, and discharge the water from the middle outlet. Adjust the flow rates to be almost the same, and both of them are in the range of 3-5m/h, keep the water running and enter into the next step.

b. Enter acid and soda: open the valve of the measuring tank of liquid NaOH and let it mix with the pure water entering the upper inlet. Adjust the valve to confine the concentration of the NaOH solution entering the upper inlet in 3-4%. The total NaOH used should be 200g/mol capacity for the anion resin. After finishing entering the soda, close the soda valve. Then open the valve of the measuring tank of the acid and let the acid mix with the pure water entering the bottom inlet. Adjust the valve to control the concentration of the acid solution entering the bottom inlet in 3-4%, too. The quantity of acid for the cation resin is about 150g/mol capacity, After finishing the acid, close the acid valve.

c. Replacement: keep entering pure water from the upper and the bottom inlet at the same flow rate until the conductivity of the discharged water from the middle outlet is less than 20µs/cm. Close the middle outlet.

d. Mix the MB anion and cation resins: Drain the water from the column until the water level is about 10cm higher than the surface of the anion resin. Pump compressed air into the column from the bottom. Make sure that the pressure of the pressed air can keep at 0.35-0.4mpa for at least 3 minutes. Observe the mix effect. Usually, after bubbling the air into the column, the mix can be down in 2 min.

e. Rinse: Rinse the mixed ion exchange resin from top to bottom until the effluent meets the requirements( usually, conductivity requirement). It takes about 30 minutes in general. Then the MB system is ready to serve.

III. Packing.

Domestic: 25kg, 25L PE bags or 1000L big bag, or as client’s request.

Export: 25L PE bags or 1000L big bag, or as client’s request.