Lithium resource utilization field

Lithium resource utilization field

The lithium content in my country's bauxite is relatively high, ranging from 0.016 to 0.03% in terms of lithium oxide. About 80% of the lithium enters the sodium aluminate solution and 20% enters the red mud. In the subsequent aluminum electrolysis process, lithium will be enriched in the electrolyte and adsorbed by the cathode, carbon slag, etc., resulting in excessive lithium content in the electrolyte, affecting the stability and production efficiency of the electrolytic cell. The separation of lithium in the sodium aluminate solution through technical measures can reduce electrolyte emissions, maintain the normal operation of electrolytic aluminum production, and utilize lithium resources in bauxite.

First, this preparation process is suitable for lithium enrichment carriers in sodium aluminate environments, and then the process conditions are controlled to enrich and precipitate lithium in the sodium aluminate solution produced by the Bayer process or sintering process, thereby separating the lithium in the solution. Then a specific dissociation process is used to dissociate lithium from the enrichment carrier to obtain a lithium solution. The enrichment carrier is recovered in the dissociation process and returned to the enrichment process for recycling, and there is no consumption during the operation process. The obtained lithium solution is purified and precipitated to obtain Li2CO3, and then industrial Li2CO3 is used as a precursor to control the process conditions to obtain Li2CO3 for batteries. By adjusting the process route, lithium phosphate, lithium fluoride and lithium hydroxide for batteries can also be obtained.

Hot sodium hydroxide (85-90 degrees) is added to bauxite to react and form sodium aluminate. After the sodium aluminate is saturated, it enters the crystallization kettle. The crystallization kettle is cooled in stages to produce crystals. The crystals are separated by solid and liquid through a leaf filter, and the liquid flows back to the front. The crystals are the product aluminum hydroxide. Aluminum hydroxide is calcined to produce alumina, or it is electrolyzed to produce metallic aluminum;

During this reaction process, the purity of alumina is not high and it will contain lithium, and the electrolytic cell will have a large amount of waste slag containing lithium;

The entire process is optimized by adding a set of adsorption devices before the saturated sodium aluminate enters the crystallization kettle to adsorb and treat lithium impurities to ensure that the purity of the aluminum product produced later is excellent;

Activated aluminum hydroxide is used as the adsorbent; aluminum hydroxide can be produced by adding sodium aluminate to carbon dioxide;

The adsorbent is adjusted by acid leaching PH 2; after acid addition, solid-liquid separation is carried out, and the liquid is filtered on the membrane. Concentration and extraction can produce lithium ions with a concentration of about 10%, and hot sodium carbonate is added to produce lithium carbonate.