Provided are an extraction agent and extraction method that selectively extract and, at a low cost, recover gallium from an acidic solution containing gallium and zinc. The gallium extraction agent comprises an amide derivative represented by general formula (I). In the formula, R.sup.1 and R.sup.2 each indicate the same or different alkyl group, R.sup.3 indicates a hydrogen atom or an alkyl group, and R.sup.4 indicates a hydrogen atom or any given group, other than an amino group, bonded to the α-carbon as an amino acid. The general formula preferably has a glycine unit, a histidine unit, a lysine unit, an aspartic acid unit, or an N-methylglycine unit. By extracting gallium from an acidic solution containing gallium and zinc by means of solvent extraction using the extraction agent, it is possible to selectively extract gallium.

Provided are an extraction agent and extraction method that selectively extract and, at a low cost, recover gallium from an acidic solution containing gallium and zinc. The gallium extraction agent comprises an amide derivative represented by general formula (I). In the formula, R.sup.1 and R.sup.2 each indicate the same or different alkyl group, R.sup.3 indicates a hydrogen atom or an alkyl group, and R.sup.4 indicates a hydrogen atom or any given group, other than an amino group, bonded to the α-carbon as an amino acid. The general formula preferably has a glycine unit, a histidine unit, a lysine unit, an aspartic acid unit, or an N-methylglycine unit. By extracting gallium from an acidic solution containing gallium and zinc by means of solvent extraction using the extraction agent, it is possible to selectively extract gallium.

Provided are a removal liquid for removing an oxide of a Group III-V element, an oxidation prevention liquid for preventing the oxidation of an oxide of a Group III-V element or a treatment liquid for treating an oxide of a Group III-V element, each liquid including an acid and a mercapto compound; and a method using each of the same liquids. Further provided are a treatment liquid for treating a semiconductor substrate, including an acid and a mercapto compound, and a method for producing a semiconductor substrate product using the same.

Provided are a removal liquid for removing an oxide of a Group III-V element, an oxidation prevention liquid for preventing the oxidation of an oxide of a Group III-V element or a treatment liquid for treating an oxide of a Group III-V element, each liquid including an acid and a mercapto compound; and a method using each of the same liquids. Further provided are a treatment liquid for treating a semiconductor substrate, including an acid and a mercapto compound, and a method for producing a semiconductor substrate product using the same.

Provided is a method for recycling indium from a panel on which an electrode layer made of indium tin oxide (ITO) is formed, comprising: S1 —removing each of pattern layers on the panel to obtain particles formed by the pattern layers; S2 —adding an acid solution to the particles so as to dissolve the substances which can be dissolved in the acid solution, and then filtering to give a solution containing indium ion; S3 —adding an alkaline solution to the solution obtained in step S2, so that metal ions other than indium ion can form precipitates with hydroxyl ion; S4 —filtering off the precipitates formed in step S3; and S5 —evaporating the solution obtained in step S4 to obtain crystals of indium salt. The method improves the reusing rate of the defective panels, is helpful to environment protection, and saves resources.

Provided is a method for recycling indium from a panel on which an electrode layer made of indium tin oxide (ITO) is formed, comprising: S1 —removing each of pattern layers on the panel to obtain particles formed by the pattern layers; S2 —adding an acid solution to the particles so as to dissolve the substances which can be dissolved in the acid solution, and then filtering to give a solution containing indium ion; S3 —adding an alkaline solution to the solution obtained in step S2, so that metal ions other than indium ion can form precipitates with hydroxyl ion; S4 —filtering off the precipitates formed in step S3; and S5 —evaporating the solution obtained in step S4 to obtain crystals of indium salt. The method improves the reusing rate of the defective panels, is helpful to environment protection, and saves resources.

This application discloses the method for separating element or isotopes such as protactinium and gallium and isotopes thereof from a corresponding mixture which method comprises contacting the mixture with a carbon-based separation material, wherein the carbon-based separation material selectively associates with the element or isotope thereof.

This application discloses the method for separating element or isotopes such as protactinium and gallium and isotopes thereof from a corresponding mixture which method comprises contacting the mixture with a carbon-based separation material, wherein the carbon-based separation material selectively associates with the element or isotope thereof.

The gallate solution is obtained from an alkaline gallium-containing solution. Gallium is sorbed from a recycled solution on a divinylbenzene polymer-based ionite, gallium is desorbed with a solution of sulfuric acid to obtain a gallium-containing eluate, followed by concentration of gallium by converting it to a solid phase by neutralisation of the eluate with a caustic solution with precipitation of a gallium hydroxide precipitate at a given temperature. Thickening and filtration of the precipitate are carried out with its further dissolution in a caustic solution until a given concentration of gallium in the solution is obtained. The method allows to increase the concentration of gallium by converting it to the solid phase when neutralising acidic eluates with an alkaline solution, which simplifies the concentration process and reduces the number of technological operations and, as a result, reduces the cost of gallium production.

Disclosed are applications of a carboxylic compound serving as an extracting agent and a metal ion extraction method. The carboxylic compound is provided with the structure as represented by formula I. The extracting agent as represented by formula I is characterized by a secondary atom at position α of the carboxyl group, in distinction from a primary carbon carboxylic acid at position α and a tertiary carbon carboxylic acid at position α, the presence of a secondary carbon carboxylic acid provides a proper steric hindrance, provides improved selectivity with respect to ions, and provides a high separation coefficient, low stripping acidity, and high load rate when used for the extraction and separation of metal ions; moreover, the carboxylic compound of formula I has great stability and low aqueous solubility, allows an extraction process to be stable, reduces environmental pollution, reduces costs, and provides significant application prospects.