The main treatment methods of waste denitration catalyst currently are landfill, burning and recycling, the first two methods have huge potential dangers on the environment. In addition, due to full implementation of emission reduction, the waste catalyst generated increasingly; the treatment ways of landfill and incineration will not only occupy a lot of land, but also bring a secondary pollution to the environment. The way of recycling includes used as boiler slag recycling vulcanizing agent and raw materials recovery, thus to apply for the production of new catalyst, the raw materials of steel plants; wherein, heavy metal with toxic and its relatively components must be separated. The way of basic recycling titanium, vanadium and tungsten from tungsten trioxide waste plate denitration catalyst is as follows:

 

1. Carry out the pretreatment by purging the catalyst with dry compressed air for 1h;

2. Peel off the paste of waste catalyst from the stencil and place it in a ball milling for 10 hours to obtain the recycling materials;

3. Recycling titanium dioxide: the certain concentration of sodium carbonate solution and recycling catalyst material are reacted to obtain sodium titanate solution containing other metal elements;

4. Add sulfuric acid and stir for 5 hours, then obtain the titanium dioxide after filtered, washed with water, dried and calcined;

5. Add HCl into the resulting filtrate of sodium titanate centrifuged to adjust the pH to 8.0~9.0, then add quantitative magnesium chloride, dissolve by stirring to get a white precipitate, and then get magnesium silicate by separating and drying the precipitate;

6. Add ammonium chloride into the filtrate after magnesium precipitated; stir to dissolve to obtain a vanadate precipitate, then calcined to obtain the vanadium pentoxide;

7. Add HCl of 5%~10% by volume ratio into the filtrate after vanadium precipitated to adjust pH to 4.5~5.0, then add calcium chloride solution, filtered and washed to obtain calcium tungstate.

 

The adding of Na, Cl elements in the recovery process of basic hydrometallurgical does not bring out the secondary pollution harmful pollutants, and the recovered titanium dioxide is of high purity which can be directly used for coating or catalyst producing.