Method for refining beryllium by molten salt electrolysis

Abstract

The present disclosure relates to a method for refining beryllium by molten salt electrolysis, the method comprises: firstly, constructing an electrochemical system, wherein an anode chamber contains an anode molten salt electrolyte, a crude beryllium anode is inserted in the anode molten salt electrolyte, a cathode chamber contains a cathode molten salt electrolyte, a cathode is inserted in the cathode molten salt electrolyte, the anode molten salt electrolyte and the cathode molten salt electrolyte are not in contact with each other but are connected with each other via a liquid alloy at the bottom of the inside of an electrolysis cell; and applying a current for electrolysis to obtain refined solid beryllium at the cathode.

1 . A method for refining beryllium by molten salt electrolysis, comprising the following steps:
 (1) Constructing an electrochemical system: the electrolytic cell is divided into an anode chamber and a cathode chamber, wherein the anode chamber contains an anode molten salt electrolyte, a crude beryllium anode is inserted in the anode molten salt electrolyte, the cathode chamber contains a cathode molten salt electrolyte, a cathode is inserted in the cathode molten salt electrolyte, a liquid alloy is at the bottom of the inside of the electrolytic cell: the anode molten salt electrolyte and the cathode molten salt electrolyte are not in contact with each other but are connected via the liquid alloy at the bottom of the inside of the electrolytic cell;   (2) Applying a current for electrolysis, the beryllium metal in the anode is oxidized to beryllium ions, the beryllium ions from the anode are moved into the anode molten salt electrolyte, the beryllium ions in the anode molten salt electrolyte are reduced to beryllium metal at the interface between the anode molten salt electrolyte and the liquid alloy, the beryllium metal at the interface between the anode molten salt electrolyte and the liquid alloy is dissolved into the liquid alloy, meanwhile the beryllium metal in the liquid alloy is oxidized to beryllium ions at the interface between the liquid alloy and the cathode molten salt electrolyte, the beryllium ions at the interface between the liquid alloy and the cathode molten salt electrolyte are moved into the cathode molten salt electrolyte, the beryllium ions in the cathode molten salt electrolyte are reduced to beryllium metal on the cathode surface.   
     
     
         2 . A method for refining beryllium by molten salt electrolysis according to  claim 1 , the cathode is a nickel, tungsten or molybdenum cathode. 
     
     
         3 . A method for refining beryllium by molten salt electrolysis according to  claim 1 , the liquid alloy is an alloy comprised of beryllium and one or several of copper, silver, gold, manganese. 
     
     
         4 . A method for refining beryllium by molten salt electrolysis according to  claim 3 , the liquid alloy is an alloy comprised of beryllium and copper in an atomic ratio of 28:72. 
     
     
         5 . A method for refining beryllium by molten salt electrolysis according to  claim 3 , the liquid alloy is an alloy comprised of beryllium and gold in an atomic ratio of 21:79. 
     
     
         6 . A method for refining beryllium by molten salt electrolysis according to  claim 1 , the anode molten salt electrolyte is a halide molten salt containing beryllium ions, preferably the anode molten salt electrolyte is a mixture of beryllium fluoride and one or several of lithium fluoride, sodium fluoride, potassium fluoride, magnesium fluoride, and calcium fluoride. 
     
     
         7 . A method for refining beryllium by molten salt electrolysis according to  claim 1 , the cathode molten salt electrolyte is a halide molten salt containing beryllium ions, preferably the cathode molten salt electrolyte is a mixture of beryllium fluoride and one or several of lithium fluoride, sodium fluoride, potassium fluoride, magnesium fluoride, and calcium fluoride. 
     
     
         8 . A method for refining beryllium by molten salt electrolysis according to  claim 1 , under the condition of applying a current, the density of both the anode molten salt electrolyte and the cathode molten salt electrolyte is lower than the density of the liquid alloy. 
     
     
         9 . A method for refining beryllium by molten salt electrolysis according to  claim 1 , the purity of the crude beryllium in the crude beryllium anode is not lower than 90%. 
     
     
         10 . A method for refining beryllium by molten salt electrolysis according to  claim 1 , the anode current density is between 0.1 A/cm 2  and 1.5 A/cm 2 , the electrolysis temperature is between 600° C. and 1100° C.