Method for recovering waste chromium-based fluorination catalyst

Method for recovering waste chromium-based fluorination catalyst

  • CN 107,376,953 B
  • Filed: 08/03/2017
  • Issued: 04/21/2020
  • Est. Priority Date: 08/03/2017
  • Status: Active Grant
First Claim
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1. A method for recovering a waste chromium-based fluorination catalyst is characterized by comprising the following steps:

  • 1) pressure fluorination;

    introducing anhydrous hydrogen fluoride into a reaction tube filled with the waste chromium-based fluorination catalyst at a certain temperature, and controlling a certain airspeed and pressure to perform fluorination to obtain a fluorinated catalyst;

    wherein;

    the pressure fluorination temperature is 300-500 ℃

    , and the pressure fluorination time is 2-24 h;

    during the pressure fluorination, the airspeed is controlled to be 600-2000 h-1Controlling the pressure to be 0.2-0.5 Mpa;

    2) dissolving;

    grinding the fluorinated catalyst, adding an excessive hydrofluoric acid solution, heating for dissolving, filtering while the solution is hot, and collecting filtrate;

    wherein;

    the ground granularity is 20-200 meshes;

    the concentration of the hydrofluoric acid solution is 10-50%;

    the mass ratio of the fluorinated catalyst to the hydrofluoric acid solution is 1;

    1.5-8;

    the heating and dissolving temperature is 20-100 ℃

    , and the dissolving time is 2-12 h;

    3) and (3) purification;

    concentrating and crystallizing the collected filtrate, filtering, continuously concentrating and crystallizing the filtrate, repeating the steps, collecting all filter cakes, washing and drying to obtain a chromium fluoride product;

    wherein;

    the concentration temperature is 60-120 ℃

    , and the crystallization temperature is-10-20 ℃

    ;

    the washing is performed by using 10-30% hydrofluoric acid solution, and the drying temperature is 80-120 ℃

    .

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