METHOD FOR CREATING A LITHIUM ADSORBENT

Abstract

The present invention relates to a method for creating a lithium adsorbent.

Claims

1. Method for creating the lithium adsorbent H.sub.1.6Mn.sub.1.6O.sub.4 comprising the following steps: a. Calcining an intermediate product LiMnO.sub.2 in air to obtain the precursor Li.sub.1.6Mn.sub.1.6O.sub.4; b. Eluting the precursor Li.sub.1.6Mn.sub.1.6O.sub.4 using acetic acid (CH.sub.3COOH), sodium peroxodisulfate (Na.sub.2S.sub.2O.sub.8)) and/or ammonium peroxodisulfate ((NH.sub.4).sub.2S.sub.2O.sub.8) or a mixture of the above-mentioned eluents/a solution which contains the above-mentioned eluents and c. then separating, washing with distilled water and drying to obtain the lithium adsorbent H.sub.1.6Mn.sub.1.6O.sub.4.

2. Method according to claim 1, characterized in that the intermediate product LiMnO.sub.2 is produced by means of hydrothermal synthesis in an autoclave from a precursor, dimanganese trioxide (M.sub.2nO.sub.3) and LiOH.

3. Method according to claim 2, characterized in that the hydrothermal synthesis occurs in the autoclave under pressure in a pressure range of 10 bar and 200 bar.

4. Method according to claim 2, characterized in that the precursor, dimanganese trioxide (M.sub.2nO.sub.3), is produced from manganese dioxide (MnO.sub.2) through calcination.

5. Method according to claim 2, characterized in that the calcination of the intermediate product, LiMnO.sub.2, (step a) in claim 1) occurs at a temperature of 350° C. to 1000° C., preferably at 400° C., and/or that the calcination lasts for 3 hours to 5 hours, preferably 4 hours.

6. Method according to claim 2, characterized in that the intermediate product, LiMnO.sub.2, is produced from a precursor, dimanganese trioxide (M.sub.2nO.sub.3) and LiOH, at an elevated pressure and/or a temperature of about 100 to 200° C., preferably at 120° C., and/or that the hydrothermal synthesis lasts about 24 hours.

7. Method according to claim 4, characterized in that the calcination of the precursor, dimanganese trioxide (M.sub.2nO.sub.3) takes place at a temperature of about 650° C., and/or lasts six hours.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Further advantages and advantageous embodiments of the invention can be seen in the following drawing and its description. All the characteristics disclosed in the FIGURE, its description and the patent claims are fundamental to the invention, both individually as well as in any combination with each other.

[0027] The single FIG. 1 shows the method according to the invention for creating an adsorbent in the form of a block diagram. The method begins with the starting product, manganese dioxide MnO.sub.2 In the first step (block 101), this starting product is calcined, preferably at a temperature of about 650° C. and over a duration of about six hours. The calcination results in the production of a precursor, dimanganese trioxide Mn.sub.2O.sub.3.

DETAILED DESCRIPTION

[0028] This precursor is placed in an autoclave together with lithium precursors (preferred) LiOH (block 103). Lithium manganese dioxide LiMnO.sub.2 is produced in it through hydrothermal synthesis. A temperature of about 120° C. and a duration of 24 hours have proved to be suitable process parameters. It is also beneficial if the hydrothermal synthesis occurs at pressures of 10 bar or higher.

[0029] In a further step (block 105), this lithium manganese dioxide is calcined, preferably at a temperature of 400° C. and for a duration of four hours. This results in the precursor Li.sub.1.6Mn.sub.1.6O.sub.4 of the adsorbent.

[0030] In a subsequent step (block 107), this precursor is washed with acetic acid, sodium peroxodisulfate and/or ammonium peroxodisulfate.

[0031] It is also possible to use these acids in diluted form rather than in pure form. The mixture of the eluent or a solution

[0032] that contains the abovementioned eluents could also be used. The following mixing ratios have proved to be suitable:

[0033] If acetic acid is used, the proportion of acetic acid in the solution is between 0.1% and 100%.

[0034] If sodium peroxodisulfate is used, this proportion is preferably between 0.05% and 65%; if ammonium peroxodisulfate is used, this proportion is between 0.05% and 65%.

[0035] The liquid is then filtered to separate the adsorbent which has the form of a granular sub stance.

[0036] This adsorbent is then washed with distilled water and dried. This results in the desired adsorbent H.sub.1.6Mn.sub.1.6O.sub.4 which can be used in an adsorption column to increase the concentration or to obtain lithium ions.