Process for recycling waste carbide

Patent metadata

Field	Value
Publication number	US-2016208398-A1
Application number	US-201414908495-A
Country	US
Kind code	A1
Filing date	Jul 30, 2014
Priority date	Jun 17, 2014
Publication date	Jul 21, 2016
Grant date	—

Abstract

The present invention provides a process for recycling waste carbide, wherein the waste carbide is directly used as anode and electrolyzed in the molten salt, comprising the following steps: 1) the vacuum dehydrating of the molten salt electrolyte; 2) electrolyzing the waste carbide, which is used as anode, and an inert electrode, which is used as cathode in the molten salt electrolyte with the electrolysis temperature of 350˜1000° C.; 3) separating and collecting the metal powder obtained by electrolysis from molten salt medium. According to the technical solutions of the present invention, tungsten and cobalt ions can be dissolved from the anode material-waste carbide directly into the molten salt medium and deposited on the cathode plate with being driven by the electrolysis voltage, to obtain the metal powder particles. The tungsten, cobalt and other products obtained by electrolysis can be used as carbide materials, high temperature structural materials, weapons materials, photocatalytic materials, etc., and can be applied to the fields of processing production, aerospace, military industry, environment and energy, and the like. This method has a short process, has no solid/liquid/gas waste emissions, and is environment-friendly.

First claim

What is claimed is:

1 . A process for recycling waste carbide, characterized in that, the waste carbide is directly used as anode and electrolyzed in the molten salt, comprising the following steps:
1) the vacuum dehydrating of the molten salt electrolyte; wherein the composition of said molten salt electrolyte is (x)A-(y)B-(z)NaCl, wherein x is the mole percentage content of A, y is the mole percentage content of B, z is the mole percentage content of NaCl; x is in the range of 5˜70 mol %, y is in the range of 0˜60 mol %, z is in the range of 0˜50 mol %; said A is one or more of CaCl 2 , KCl and LiCl, said B is one or more of WCl 6 , WCl 4 , WCl 2 , Na 2 WO 4 , K 2 WO 4 and CaWO 4 ; 2) electrolyzing the waste carbide which is used as anode, and an inert electrode which is used as cathode, in the molten salt electrolyte with the electrolysis temperature of 350˜1000° C.; 3) separating and collecting the metal powder obtained by electrolysis from the molten salt medium.

2 . The process according to claim 1 , characterized in that, in said step 2), one of the titanium plate, stainless steel plate, carbon plate, or graphite carbon is used as the cathode.

3 . The process according to claim 1 , characterized in that, in said step 2), galvanostatic electrolysis is performed and the current density is controlled in 0.02˜1.0 A/cm 2 ; or potentiostatic electrolysis is performed and the cell voltage is controlled in 1.0˜10 V.

4 . The process according to any one of claims 1 - 3 , characterized in that, in said step 2), a protective gas is used during the electrolysis, wherein the protective gas is a mixed gas of one or more of oxygen, air, nitrogen and argon for W, W—Co powder products, and the volume content of oxygen in the mixed gas is 10-20%, and wherein the electrolysis way is potentiostatic electrolysis, and the cell voltage is controlled in 2.8˜3.2 V.

5 . The process according to any one of claims 1 - 3 , characterized in that, in said step 2), a non-oxidizing gas is used as the protective gas during the electrolysis for WC powder product, wherein the non-oxidizing gas is nitrogen or argon, and wherein galvanostatic electrolysis is performed, and the cell voltage is kept constant in 1.0˜3.0 V by controlling the current intensity during the electrolysis.

6 . The process according to any one of claims 1 - 3 , characterized in that, in said step 2), a mixed gas containing oxygen is used for W, W—Co powder products, wherein the volume ratio of oxygen in the mixed gas is 10-20%, and other gas in the mixed gas is nitrogen or argon, and wherein galvanostatic electrolysis is performed, and the cell voltage is kept constant to be 1.0˜3.0 V by controlling the current intensity during the electrolysis.

7 . The process according to any one of claims 1 - 3 , characterized in that, in said step 3), pickling, washing, filtrating and vacuum drying are used to separate the powder products from the molten salt medium.

Assignees

• Univ Beijing Technology

Inventors

• Nie Zuoren
• Xi Xiaoli

Classifications

• C25C3/34 Primary

  of metals not provided for in groups C25C3/02 - C25C3/32 · CPC title

• C25C7/005

  of cells for the electrolysis of melts (C25C7/02 - C25C7/06 take precedence) · CPC title