Abstract: Provided is a method of inhibiting degradation of an extractant by an anhydrous environment avoiding and metal stripping, the method including the steps of: (a) stopping the addition of soda ash (Na2CO3) to an extracting reaction tank; (b) starting solution recirculation and stopping solvent recirculation of a settler; (c) supplying a solvent from a loaded organic tank to a scrubbing reaction tank, in which the scrubbing reaction tank, stripping reaction tank and extracting reaction tank are connected for circulation and operating stirrers of the scrubbing reaction tank, stripping reaction tank and extracting reaction tank; (d) supplying a sulfuric acid solution having a controlled concentration with a diluting solution to the stripping reaction tank; (e) transferring the solvents of the settler, the loaded organic tank and all the pipes to the scrubbing reaction tank; and (f) stopping the step (e) and initiating solvent recirculation.

Abstract: A method of inhibiting degradation of an extractant by utilizing several auxiliary means in the DSX process: includes (a) preparing adjustment of the concentration of an extractant of a DSX solvent to a certain range; (b) extracting a metal contained in a pregnant leached solution by adjusting the ratio of the extractant and the diluent in the DSX solvent to a certain range; (c) measuring the pH of the aqueous phase solution by separating mixture into the aqueous phase solution and the organic phase solvent using a settler after step of extracting; (d) controlling the pH by adding soda ash (Na2CO3) so as to maintain the pH of the aqueous phase solution to be 3 to 7; and (e) scrubbing with scrubbing solution having a zinc concentration of 2 to 20 g/L by zinc sulfate (ZnSO4) to remove the manganese from the organic phase solvent containing the extracted metal.

Abstract: Provided is a method for inhibiting extractant degradation comprising preparing step, extracting step and scrubbing step, the method including: (a) the preparing step of a DSX solvent by adjusting the extractant concentration of the DSX solvent to a specific range; (b) the extracting step of metal included in the feed solution by adjusting the ratio of the organic (solvent) and an aqueous (solution) as a feed solution; (c) the scrubbing step of adjusting the zinc concentration of the solution using zinc sulfate; and (d) stripping step.

Abstract: Provided is a method for inhibiting extractant degradation in the DSX process through the metal extraction control, the method comprising steps of: (a) adding limestone to a copper solvent extraction-raffinate to precipitate iron (Fe) and aluminum (Al) as a slurry, recovering a clarifying liquid; and (b) adding sulfuric acid to the recovered clarifying liquid to adjust the pH thereof.

Abstract: Provided is a method for inhibiting extractant degradation in the DSX process through the manganese extraction control, the method comprising: (a) stirring DSX solvent and DSX feed solution, which is a solution containing a valuable metal from which iron has been removed in an agitator, in which soda ash (Na2CO3) is further added to maintain a constant pH; and (b) scrubbing the manganese from the DSX solvent, extracted in step (a).

Abstract: Provided is a method for recovering a valuable metal sulfide, the method including: (a) adding limestone to a residual solution including a valuable metal to remove iron and aluminum; (b) adding sulfuric acid and a sulfide to the solution from which the iron and aluminum are removed to recover the valuable metal sulfide; and (c) adding air or sulfuric acid to the solution from which the valuable metal sulfide is recovered to remove sulfur.

Abstract: Provided is a method for inhibiting extractant degradation by a diluent and an extractant input manner, the method including steps of: (a) determining and analyzing the total volume of the DSX solvent when the diluent and the extractant, which are the DSX solvents, are added in the DSX process and identifying the concentration of the extractant; (b) calculating an extractant concentration according to an amount of the diluent to be added based on the analysis value of step (a), and then adding the extractant; (c) determining the ratio between the extractants through analysis after adding the extractants; (d) adding the extractant to be needed when the ratio between extractants is out of the range; and (e) adding the diluent and analyzing the ratio between the extractants.

Abstract: Provided is a method for measuring the concentration of aliphatic hydroxy oxime and neodecanoic acid using gas chromatography. The method includes the steps of: (a) removing, from a reference material containing an extractant and a diluent, the diluent using a silica column; (b) generating a calibration curve by calculating each peak area of aliphatic hydroxy oxime and neodecanoic acid, which are extractants, by peak integration of gas chromatograms; and (c) calculating the peak area of the organic solvent used in DSX process through the steps (a) and (b) and comparing the peak area with the calibration curve of the step (b) to measure the concentration of aliphatic hydroxy oxime and neodecanoic acid.

Abstract: A method of inhibiting degradation of an extractant by utilizing several auxiliary means in the DSX process: includes (a) preparing adjustment of the concentration of an extractant of a DSX solvent to a certain range; (b) extracting a metal contained in a pregnant leached solution by adjusting the ratio of the extractant and the diluent in the DSX solvent to a certain range; (c) measuring the pH of the aqueous phase solution by separating mixture into the aqueous phase solution and the organic phase solvent using a settler after step of extracting; (d) controlling the pH by adding soda ash (Na2CO3) so as to maintain the pH of the aqueous phase solution to be 3 to 7; and (e) scrubbing with scrubbing solution having a zinc concentration of 2 to 20 g/L by zinc sulfate (ZnSO4) to remove the manganese from the organic phase solvent containing the extracted metal.

Abstract: Provided is a method of inhibiting degradation of an extractant by an anhydrous environment avoiding and metal stripping, the method including the steps of: (a) stopping the addition of soda ash (Na2CO3) to an extracting reaction tank; (b) starting solution recirculation and stopping solvent recirculation of a settler; (c) supplying a solvent from a loaded organic tank to a scrubbing reaction tank, in which the scrubbing reaction tank, stripping reaction tank and extracting reaction tank are connected for circulation and operating stirrers of the scrubbing reaction tank, stripping reaction tank and extracting reaction tank; (d) supplying a sulfuric acid solution having a controlled concentration with a diluting solution to the stripping reaction tank; (e) transferring the solvents of the settler, the loaded organic tank and all the pipes to the scrubbing reaction tank; and (f) stopping the step (e) and initiating solvent recirculation.

Abstract: Provided is a method for inhibiting extractant degradation by a diluent and an extractant input manner, the method including steps of: (a) determining and analyzing the total volume of the DSX solvent when the diluent and the extractant, which are the DSX solvents, are added in the DSX process and identifying the concentration of the extractant; (b) calculating an extractant concentration according to an amount of the diluent to be added based on the analysis value of step (a), and then adding the extractant; (c) determining the ratio between the extractants through analysis after adding the extractants; (d) adding the extractant to be needed when the ratio between extractants is out of the range; and (e) adding the diluent and analyzing the ratio between the extractants.

Abstract: Provided is a method for inhibiting extractant degradation in the DSX process through the manganese extraction control, the method comprising: (a) stirring DSX solvent and DSX feed solution, which is a solution containing a valuable metal from which iron has been removed in an agitator, in which soda ash (Na2CO3) is further added to maintain a constant pH; and (b) scrubbing the manganese from the DSX solvent, extracted in step (a).

Abstract: Provided is a method for inhibiting extractant degradation in the DSX process through the metal extraction control, the method comprising steps of: (a) adding limestone to a copper solvent extraction-raffinate to precipitate iron (Fe) and aluminum (Al) as a slurry, recovering a clarifying liquid; and (b) adding sulfuric acid to the recovered clarifying liquid to adjust the pH thereof.

Abstract: Provided is a method for inhibiting extractant degradation comprising preparing step, extracting step and scrubbing step, the method including: (a) the preparing step of a DSX solvent by adjusting the extractant concentration of the DSX solvent to a specific range; (b) the extracting step of metal included in the feed solution by adjusting the ratio of the organic (solvent) and an aqueous (solution) as a feed solution; (c) the scrubbing step of adjusting the zinc concentration of the solution using zinc sulfate; and (d) stripping step.

Abstract: Provided is a method for measuring the concentration of aliphatic hydroxy oxime and neodecanoic acid using gas chromatography. The method includes the steps of: (a) removing, from a reference material containing an extractant and a diluent, the diluent using a silica column; (b) generating a calibration curve by calculating each peak area of aliphatic hydroxy oxime and neodecanoic acid, which are extractants, by peak integration of gas chromatograms; and (c) calculating the peak area of the organic solvent used in DSX process through the steps (a) and (b) and comparing the peak area with the calibration curve of the step (b) to measure the concentration of aliphatic hydroxy oxime and neodecanoic acid.

Abstract: Provided is a method for recovering a valuable metal sulfide, the method including: (a) adding limestone to a residual solution including a valuable metal to remove iron and aluminum; (b) adding sulfuric acid and a sulfide to the solution from which the iron and aluminum are removed to recover the valuable metal sulfide; and (c) adding air or sulfuric acid to the solution from which the valuable metal sulfide is recovered to remove sulfur.

Abstract: Provided is a method for measuring the concentration of bis(2,4,4-trimethylpentyl) phosphinic acid using ICP-OES, the method including the steps of: (a) decomposing and dissolving an organic solvent into an acid; (b) preparing a phosphorus reference solution and producing a calibration curve using the phosphorus reference solution; and (c) measuring the phosphorus concentration (mg/L) of the solution of step (a) using the calibration curve of step (b) and calculating the concentration (v/v %) of bis(2,4,4-trimethylpentyl) phosphinic acid in the organic solvent using the phosphorus concentration.