Titanium-series lithium ion exchanger, and preparation method of precursor thereof

Abstract

The invention discloses a titanium lithium ion exchanger and a preparation method of a precursor thereof. The preparation method comprises the following steps: 1) processing secondary-washing metatitanic acid in a sulfuric acid method titanium dioxide production process into slurry by using deionized water, adjusting the pH value to 7-12, and aging the slurry; 2) adjusting the pH value to 4-7 by using an acidic solution, aging the slurry, performing filter pressing, and water-washing the slurry to obtain a filter cake; 3) pulping the filter cake with a saturated lithium carbonate solution to prepare slurry; 4) preparing slurry with the Li2CO3 concentration of 300-600 g / L, sand-milling the slurry, and mixing the slurry in the step 4) with the slurry obtained in the step 3); 5) carrying outfilter pressing, recycling the filtrate in the step (3), calcining the filter cake in a rotary kiln, and crushing the filter cake to obtain precursor LiXTiO2+0.5X powder. The metatitanic acid has a high specific surface area, a lithium element can be rapidly migrated into a titanium source during calcination, so that a precursor can be prepared at low lithium source consumption and short calcination time, and continuous production can be realized. The product is large in batch yield, good in batch stability and high in productivity.

Description

technical field [0001] The invention relates to a titanium-based lithium ion exchanger and a method for preparing a precursor thereof, belonging to the field of inorganic nonmetals, in particular to the preparation field of a titanium-based lithium ion exchanger. Background technique [0002] Lithium and its compounds are important strategic materials for national economy and national defense construction, and are widely used in many fields such as glass, ceramics, aviation, nuclear energy and new energy. According to the annual report published by the United States Geological Survey (USGS) in January 2016, the world's proven onshore lithium resource reserves in terms of metal lithium are about 14 million tons, of which reserves in salt lake brine account for 70%. % to 80%; and the amount stored in seawater is about 260 billion tons. Therefore, in order to meet the needs of sustainable development, scholars from various countries are actively looking for new technologies fo...

AI Technical Summary

Problems solved by technology

The dry ball mill has poor mixing effect and high energy consumption. With the wear of the grinding media, a large amount of impurities will be brought in, which will affect the product performance.

The material particles after wet sand grinding are fine, and the filtration performance is poor. The water in the slurry can only be evaporated by spray drying and other methods, which requires high energy consumption, high equipment requirements, and low production capacity.

The prior art often directly adds solid lithium carbonate to the metatitanic acid solution after desulfurization, because the wettability of lithium carbonate solid powder in the viscous slurry is very poor, and the unwetted lithium carbonate powder becomes more agglomerated. Not conducive to the dispersion of lithium sources, not suitable for large-scale production equipment

At the same time, lithium carbonate has a strong alkalinity, and when ammonium salt is mixed with it, a large amount of ammonia gas will be released, which has a great impact on the working environment of workers.

[0008] The calcination process of lithium titanium oxide in the prior art usually uses a roller kiln for calcination, and the calcination batch is limited by the capacity of the box in the roller kiln, and during the calcination process, the material is not turned over, and the heat is conducted from the outside of the box to the center of the material, resulting in material The heating inside and outside is not uniform, the crystal growth environment is poor, and the precursor crystal is incomplete

[0009] The above problems make it difficult to control the quality of titanium-based lithium ion exchangers, and it is not easy to mass-produce and the cost is too high, so it is difficult to popularize and apply

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