Method for preparing manganese oxide ionic sieve precursor LixMn3-xO4 by using one-step method

Abstract

The invention discloses a method for preparing a manganese oxide ionic sieve precursor LixMn3-xO4 by using a one-step method. The method comprises the following steps: mixing a manganese salt, an oxidant and lithium-containing inorganic powder, preparing slurry through a one-step liquid-solid reaction in a sealed environment, directly drying the slurry, and further carrying out roasting annealingtreatment, thereby obtaining manganese oxide ionic sieve precursor LixMn3-xO4. The manganese oxide ionic sieve precursor LixMn3-xO4 is subjected to lithium removal modification in an acid solution, that is, lithium can be selectively adsorbed from lithium-containing solutions such as brine water and seawater. The preparation disclosed by the invention is simple in operation process, low in sintering temperature, free of wastewater or waste material generation, rich in raw material source, low in price, low in energy consumption and is an energy-saving and environment-friendly green and economic lithium ionic sieve production method.

Description

technical field [0001] The invention belongs to the field of energy-saving production of inorganic compounds, in particular to one-step preparation of manganese ion sieve precursor Li x mn 3-x o 4 Methods. Background technique [0002] Li x mn 3-x o 4 It is a general term for manganese oxide ion sieve precursors. The most studied lithium manganese oxide ion sieve precursors are LiMn 2 o 4 , Li 1.33 mn 1.67 o 4 (Li 4 mn 5 o 12 ) and Li 1.6 mn 1.6 o 4 (LiMnO 2 ). Usually, the methods for preparing the above precursors include soft chemical methods, sol-gel methods, hydrothermal methods, etc. The existing synthesis methods generally use MnOOH as a manganese source to synthesize LiMnO 2 , and the synthesis of MnOOH itself is relatively complicated, requiring high operating conditions, and MnOOH is unstable in the air, which is not conducive to industrial production; in the preparation process of the hydrothermal method, other additives such as oxidants need to ...

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Problems solved by technology

The raw material used in this document is the trivalent manganese raw material Mn 2 o 3 , instead of manganese salt, the reaction process not only has high temperature and high energy consumption, but also has a complicated preparation process and a low degree of industrialization;

[0005] Also, "CN103121724A prepares lithium ion sieve MnO 2 0.5H 2 O and its precursor Li 1.6 mn 1.6 o 4 method", using inorganic manganese salts and lithium salts as raw materials, one-step hydrothermal synthesis of intermediates and then low-temperature roasting to obtain the required precursor Li 1.6 mn 1.6 o 4 ; Then carry out acid treatment to the precursor, extract the Li in it, become H-type ion sieve, and then get the ion sieve adsorbent MnO which has sieving effect to lithium ion through washing, filtering and drying 2 0.5H 2 O; obtained by hydrothermal synthesis first, and then roasted, the preparation process is complicated and the preparation time is long

[0006] In addition, "CN106311190A preparation method of porous manganese lithium ion sieve adsorbent" uses manganese salt and lithium salt as raw materials, uses chitosan solution as dispersant, undergoes hydrothermal reaction, and roasts at low temperature to obtain lithium ion sieve precursor Li 4 mn 5 o 12 ; Then the precursor is acid-treated, the Li therein is extracted, washed with acid leaching, filtered and dried to obtain lithium ion sieve H 4 mn 5 o 12 In this patent, it takes multi-step treatment to obtain the precursor, hydrothermal and roasting, the treatment process is complicated, and the reaction time is long. The prepared adsorbent takes more than 10 hours to reach the adsorption equilibrium, and the adsorption time is long

[0007] It can be seen that the preparation methods in the prior art do not really realize the simplification of the process and the good adsorption effect. The present invention is based on the simple preparation process (one-step method) and the good preparation method of the obtained adsorbent.

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