Provided are a battery-level Ni—Co—Mn mixed solution and a preparation method for a battery-level Mn solution, the steps thereof comprising: acid dissolution (S1), alkalization to remove impurities (S2), synchronous precipitation of calcium, magnesium, and lithium (S3), deep ageing to remove impurities (S4), synergistic extraction (S5), and refining extraction (S6). The steps of deep ageing to remove impurities (S4) and synergistic extraction (S5) comprise: performing deep ageing on a filtrate obtained from the step of synchronous precipitation of calcium, magnesium, and lithium (S3), and after performing filtration to remove impurities, obtaining an aged filtrate; using P204 to extract the aged filtrate and obtain a loaded organic phase, and subjecting the loaded organic phase to staged back-extraction to obtain the battery-level Ni—Co—Mn mixed solution and a Mn-containing solution. By means of the cooperation between the multiple process steps of synchronous precipitation of calcium, magnesium, and lithium (S3), deep ageing to remove impurities (S4), and synergistic extraction (S5), the impurity content of the obtained battery-level Ni—Co—Mn mixed solution is significantly lowered, and the battery-level Ni—Co—Mn mixed solution can be directly used to prepare a lithium battery ternary precursor material. At the same time, the battery-level Mn solution can also be obtained, which is favorable for large-scale applications of the process and increasing economic benefits.

Provided are a battery-level Ni—Co—Mn mixed solution and a preparation method for a battery-level Mn solution, the steps thereof comprising: acid dissolution (S1), alkalization to remove impurities (S2), synchronous precipitation of calcium, magnesium, and lithium (S3), deep ageing to remove impurities (S4), synergistic extraction (S5), and refining extraction (S6).

The steps of deep ageing to remove impurities (S4) and synergistic extraction (S5) comprise: performing deep ageing on a filtrate obtained from the step of synchronous precipitation of calcium, magnesium, and lithium (S3), and after performing filtration to remove impurities, obtaining an aged filtrate; using P204 to extract the aged filtrate and obtain a loaded organic phase, and subjecting the loaded organic phase to staged back-extraction to obtain the battery-level Ni—Co—Mn mixed solution and a Mn-containing solution. By means of the cooperation between the multiple process steps of synchronous precipitation of calcium, magnesium, and lithium (S3), deep ageing to remove impurities (S4), and synergistic extraction (S5), the impurity content of the obtained battery-level Ni—Co—Mn mixed solution is significantly lowered, and the battery-level Ni—Co—Mn mixed solution can be directly used to prepare a lithium battery ternary precursor material. At the same time, the battery-level Mn solution can also be obtained, which is favorable for large-scale applications of the process and increasing economic benefits.

A method for producing lithium hydroxide that allows reducing a load of removing divalent or more ions with an ion-exchange resin is provided. The method for producing lithium hydroxide includes steps (1) to (3) below. (1) a neutralization step: a step of adding an alkali to a first lithium chloride containing liquid to obtain a post-neutralization liquid, (2) an ion-exchange step: a step of bringing the post-neutralization liquid into contact with an ion-exchange resin to obtain a second lithium chloride containing liquid, and (3) a conversion step: a step of electrodialyzing the second lithium chloride containing liquid to obtain a lithium hydroxide containing liquid. Since this producing method allows roughly removing divalent or more ions in the neutralization step, a load of metal removal with the ion-exchange resin is reducible.

A method for producing a mixed metal solution containing manganese ions and at least one of cobalt ions and nickel ions, the method including: an Al removal step of subjecting an acidic solution containing at least manganese ions and aluminum ions, and at least one of cobalt ions and nickel ions, to removal of the aluminum ions by extracting the aluminum ions into a solvent while leaving at least a part of the manganese ions in the acidic solution in an aqueous phase, the acidic solution being obtained by subjecting battery powder of lithium ion batteries to a leaching step; and a metal extraction step of bringing an extracted residual liquid obtained in the Al removal step to an equilibrium pH of 6.5 to 7.5 using a solvent containing a carboxylic acid-based extracting agent, extracting at least one of the manganese ions and at least one of the cobalt ions and the nickel ions into the solvent, and then back-extracting the manganese ions and at least one of the cobalt ions and nickel ions.

Provided is a method for producing a lithium-containing solution that allows increasing a content rate of lithium in a solution after an eluting step, and suppressing an amount of an eluted solution used in a process after the eluting step, thus suppressing production cost of lithium.

A method for producing a lithium-containing solution includes an adsorption step of bringing a lithium adsorbent obtained from lithium manganese oxide in contact with a low lithium-containing solution to obtain post-adsorption lithium manganese oxide, an eluting step of bringing the post-adsorption lithium manganese oxide in contact with an acid-containing solution to obtain an eluted solution, and a manganese oxidation step of oxidating manganese to obtain a lithium-containing solution with a suppressed manganese concentration. The adsorption step, the eluting step, and the manganese oxidation step are performed in this order, and the acid-containing solution includes the eluted solution with acid added. The method allows the usage amount of the acid in the eluting step to be suppressed, the content rate of lithium in the eluted solution after the eluting step to be increased, and thus the production cost of the lithium-containing solution to be suppressed.

The invention relates to sulfonated aminomethylated chelate resins, to a method for producing same, to the use thereof for obtaining and purifying metals, in particular rare earth metals, from aqueous solutions and organic liquids, and for producing highly pure silicon.

A method for processing positive electrode active material waste of lithium ion secondary batteries, the waste containing cobalt, nickel, manganese and lithium, the method including: a carbon mixing step of mixing the positive electrode active material waste in the form of powder with carbon to obtain a mixture having a ratio of a mass of carbon to a total mass of the positive electrode active material waste and the carbon of from 10% to 30%; a roasting step of roasting the mixture at a temperature of from 600° C. to 800° C. to obtain roasted powder; a dissolution step including a first dissolution process of dissolving lithium in the roasted powder in water or a lithium-containing solution, and a second dissolution process of dissolving the lithium in a residue obtained in the first dissolution process in water; and an acid leaching step of leaching a residue obtained in the lithium dissolution step with an acid.

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 (Na.sub.2CO.sub.3) is further added to maintain a constant pH; and (b) scrubbing the manganese from the DSX solvent, extracted in step (a).

Provided is a method for producing a lithium-containing solution that prevents the dissolution of the whole lithium manganese oxide while maintaining the efficiency of an elution step. The method for producing a lithium-containing solution comprises performing an adsorption step of contacting a lithium adsorbent obtained from lithium manganese oxide with a low lithium-containing liquid for adsorption to give post-adsorption lithium manganese oxide, an elution step of contacting the post-adsorption lithium manganese oxide with an acid solution to give a lithium-containing solution with residual manganese, and a manganese oxidation step of oxidating manganese to give a lithium-containing solution with a suppressed manganese concentration, performed in this order. The acid solution is a 0.5 mol/L or more and 4.0 mol/L or less hydrochloric acid solution. According to the production method, in the elution step, the dissolution of the whole lithium manganese oxide can be suppressed while maintaining the efficiency of exchange reaction between cations including Li.sup.+ and H.sup.+. Thus, the repeated use of the lithium adsorbent becomes possible.

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.