Method for preparing granulated inorganic adsorbent for radionuclides

Patent metadata

Field	Value
Publication number	US-9480965-B2
Application number	US-201414527941-A
Country	US
Kind code	B2
Filing date	Oct 30, 2014
Priority date	Sep 5, 2014
Publication date	Nov 1, 2016
Grant date	Nov 1, 2016

Abstract

Disclosed is a method for preparing a granulated inorganic adsorbent for radionuclides including slurry forming, solidification, drying and hardening, granulation, and washing steps: blending a dihydrogen phosphate, a powdered inorganic adsorbent raw material and a setting time regulator in water to form a slurry; adding sintered magnesia into the slurry, and blending the mixture to form a solidified slurry; setting the solidified slurry on a disk member, and naturally drying to hardening in a specific temperature range to form a hardened solid material; smashing the hardened solid material and performing vibration sieving by using a screen to obtain a granulated inorganic adsorbent for radionuclides containing residual reagents; washing the granulated inorganic adsorbent for radionuclides containing residual reagents with water, to remove the residual reagents to complete preparation, where the adsorption capacity of the granulated inorganic adsorbent for radionuclides thus prepared is in the range of 0.7 to 1.9 meq/g.

First claim

What is claimed is:

1. A method for preparing a granulated inorganic adsorbent for radionuclides, comprising the following steps:
a slurry forming step: blending a dihydrogen phosphate, a powdered inorganic adsorbent raw material and a setting time regulator in water to form a slurry;
a fixing step: adding sintered magnesia into the slurry, and blending the mixture to form a fixed slurry;
a drying and hardening step: setting the fixed slurry on a disk member, and naturally drying to hardening in a specific temperature range to form a hardened solid material;
a granulation step: smashing the hardened solid material and performing vibration sieving by using a screen, to obtain a granulated inorganic adsorbent for radionuclides containing residual reagents; and
a washing step: washing the granulated inorganic adsorbent for radionuclides containing residual reagents with water, to remove the residual reagents, so as to obtain a granulated inorganic adsorbent for radionuclides.

2. The method for preparing a granulated inorganic adsorbent for radionuclides of claim 1 , wherein the dihydrogen phosphate in the slurry formation step is one or a mixture of more than two selected from ammonium dihydrogen phosphate, potassium dihydrogen phosphate, sodium dihydrogen phosphate, calcium dihydrogen phosphate and magnesium dihydrogen phosphate.

3. The method for preparing a granulated inorganic adsorbent for radionuclides of claim 1 , wherein the percentage weight of the dihydrogen phosphate is in the range of 1 w/w % to 15 w/w %, preferably in the range of 2 w/w % to 15 w/w %, and more preferably in the range of 3 w/w % to 8 w/w %, based on the total weight of the fixed slurry.

4. The method for preparing a granulated inorganic adsorbent for radionuclides of claim 1 , wherein the powdered inorganic adsorbent raw material is one or a mixture of more than two selected from natural zeolite, artificial zeolite, titanium phosphate composited ammonium phosphomolybdate, zirconium phosphate composited ammonium phosphomolybdate, tin phosphate composited ammonium phosphosphomolybdate, metallic ferrocyanide, ferricyanide, heteropoly acid salt, ammonium phosphotungstate, zirconium phosphotungstate and zirconium phosphomolybdate, multivalent metallic phosphate, transition metallic oxyhydroxides and transition metallic hydroxides.

5. The method for preparing a granulated inorganic adsorbent for radionuclides of claim 1 , wherein the powdered inorganic adsorbent raw material is a metallic ferrocyanide, and the metallic ferrocyanide is one or a mixture of more than two selected from cadmium ferrocyanide, nickel ferrocyanide, copper ferrocyanide, cobalt ferrocyanide and zinc ferrocyanide.

6. The method for preparing a granulated inorganic adsorbent for radionuclides of claim 5 , further comprises:
dissolving a ferrocyanide salt hydrate in water to formulate a first solution containing the ferrocyanide salt hydrate at a concentration of 0.01 to 1 mol/L;
dissolving a soluble metal salt in water to formulate a second solution containing the soluble metal salt at a concentration of 0.01 to 1 mol/L;
mixing the first solution and the second solution and stirring the mixture to form a slurry-like third solution, and continuously stirring for at least 24 hr at a temperature in the range of 20° C. to 35° C.;
subjecting the third solution to centrifugal desorption or pressure filtration to remove residual reagents in the third solution, and then washing with tap water or deionized water, where this washing is performed at least one time or more;
drying at a temperature in the range of 60° C. to 90° C. to form a lump-like inorganic adsorbent raw material; and
smashing and powdering the lump-like inorganic adsorbent raw material, so as to complete the preparation.

7. The method for preparing a granulated inorganic adsorbent for radionuclides of claim 6 , wherein the ferrocyanide salt hydrate is potassium ferrocyanide or sodium ferrocyanide.

8. The method for preparing a granulated inorganic adsorbent for radionuclides of claim 6 , wherein the soluble metal salt is selected to be any of zinc nitrate, zinc sulfate, zinc chloride, zinc formate, zinc acetate, zinc acetylacetone, zinc diethyldithiocarbamate, zinc oleate, zinc stearate, zinc decanoate, zinc laurate, zinc myristate, cadmium nitrate, cadmium sulfate, cadmium chloride, cadmium formate, cadmium acetate, cadmium acetylacetone, cadmium diethyldithiocarbamate, cadmium oleate, cadmium stearate, cadmium decanoate, cadmium laurate, cadmium myristate, cobalt nitrate, cobalt sulfate, cobalt chloride, cobalt formate, cobalt acetate, cobalt acetylacetone, cobalt diethyldithiocarbamate, cobalt oleate, cobalt stearate, cobalt decanoate, cobalt laurate, cobalt myristate, nickel nitrate, nickel sulfate, nickel chloride, nickel formate, nickel acetate, nickel acetylacetone, nickel diethyldithiocarbamate, nickel oleate, nickel stearate, nickel decanoate, nickel laurate, nickel myristate, copper nitrate, copper sulfate, copper chloride, copper formate, copper acetate, copper acetylacetone, copper diethyldithiocarbamate, copper oleate, copper stearate, copper decanoate, copper laurate or copper myristate.

9. The method for preparing a granulated inorganic adsorbent for radionuclides of claim 1 , wherein the weight range of the powdered inorganic adsorbent raw material is from 20 w/w % to 60 w/w %, preferably from 30 w/w % to 50 w/w %, and more preferably from 40 w/w % to 45 w/w %, based on the total weight of the fixed slurry of 100 w/w %.

10. The method for preparing a granulated inorganic adsorbent for radionuclides of claim 1 , wherein the setting time regulator is boric acid or borax, or a mixture thereof.

11. The method for preparing a granulated inorganic adsorbent for radionuclides of claim 1 , wherein the weight range of the setting time regulator is from 0.01 w/w % to 0.1 w/w %, preferably from 0.02 w/w % to 0.08 w/w %, and more preferably from 0.03 w/w % to 0.06 w/w %, based on the total weight of the fixed slurry of 100 w/w %.

12. The method for preparing a granulated inorganic adsorbent for radionuclides of claim 1 , wherein the weight range of the water is from 10 w/w % to 40 w/w %, preferably from 20 w/w % to 38 w/w %, and more preferably from 25 w/w % to 35 w/w %, based on the total weight of the fixed slurry of 100 w/w %.

13. The method for preparing a granulated inorganic adsorbent for radionuclides of claim 1 , wherein the sintered magnesia is selected to be dead-burned magnesia, or light-burned magnesia, or a mixture thereof.

14. The method for preparing a granulated inorganic adsorbent for radionuclides of claim 1 , wherein the weight range of the sintered magnesia is from 10 w/w % to 40 w/w %, preferably from 14 w/w % to 30 w/w %, and more preferably from 18 w/w % to 25 w/w %, based on the total weight of the fixed slurry of 100 w/w %.

15. The method for preparing a granulated inorganic adsorbent for radionuclides of claim 1 , wherein the specific temperature range is 20° C. to 35° C.

16. The method for preparing a granulated inorganic adsorbent for radionuclides of claim 1 , wherein the surface hardness of the hardened solid material is at least 3H or more, and preferably at least 5H or more.

17. The method for preparing a granulated inorganic adsorbent for radionuclides of claim 1 , wherein the particle diameter of the granulated inorganic adsorbent for radionuclides containing residual reagents after vibration sieving is in the range of 0.2 to 3 mm, preferably in the range of 0.5 to 2.5 mm, and more preferably in the range of 1 to 2 mm.

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Assignees

• Iner Aec Executive Yuan

Inventors

• Chuang Li-Ching
• Liao Chi-Hung
• Chung Jen-Chieh
• Lin Kou-Min
• Chiang Sheng-Wei
• Chien Kuang-Li
• Hu zhe-cheng
• Tsai Wen-Chi

Classifications

• B01J20/0229

  Compounds of Fe · CPC title

• B01J20/165

  Natural alumino-silicates, e.g. zeolites · CPC title

• B01J20/0274

  characterised by the type of anion · CPC title

• B01J20/06

  comprising oxides or hydroxides of metals not provided for in group B01J20/04 · CPC title

• B01J20/3071

  Washing or leaching · CPC title