Solutions

Our solutions to assist Lithium extraction from spodumene are:

  • Solution 1. Concentration of the Li2SO4 solution
  • Solution 2. Purification of Li2CO3
  • Solution 3. Na2SO4 recovery as a byproduct during Li2CO3 production.
  • Solution 4. LiOH production by reaction of Li2CO3 with lime
  • Solution 5. LiOH production by electrodialysis
  • Solution 6. LiCl production
  • Solution 7. Water contaminated (tailings) treatment.

Solution 1. Concentration of the Li2SO4 solution

The sulfuric acid process for lithium extraction normally involves:

  • Heating process at 1100ºC in a rotary kiln (α-spodumene is converted to β-spodumene)
  • β-spodumene is grounded, mixed and roasted with H2SO4 at 250ºC.
  • At this stage, Li2SO4 (soluble in water) is generated and an insoluble ore residue
  • The excess of H2SO4 is neutralized with CaCO3. The kiln is then leached with water
  • Filtration for impurities removal
  • Lime addition to precipitate magnesium and soda ash to precipitate residual calcium
  • pH adjustment with H2SO4, and Li2SO4 solution concentration by multiple-e ffect evaporation (triple effect) [1]. A highly concentrated lithium-containing solution is required
  • Eventually, lithium can be precipitated as Li2CO3 by soda ash addition. Following crystallization, technical grade lithium carbonate is produced.

The utilisation of multiple-effect evaporation can assist the lithium concentration process before lithium carbonate precipitation

Solution 2 : Purification of Li2CO3

Technical-grade lithium carbonate is redissolved for impurities removal. By recrystallization, battery-grade lithium carbonate can be produced.

The utilization of crystallization technologies can facilitate battery-grade lithium carbonate production

Solution 3 : Na2SO4 recovery as a byproduct during lithium

Carbonate production:

  • Na2CO3 is added to a concentrated Li2SO4 solution in order to precipitatelithium carbonate
  • By evaporation and crystallization, lithium carbonate is obtained
  • A residual solution containing sodium sulfate can be eventually concentrated in acrystallizer for Na2SO4 (by-product) recovery.

The utilisation of evaporation-crystallization technology can facilitate sodium sulfate recovery (by-product).

Solution 4. LiOH production by reaction of Li2CO3 with Ca(OH)2

Li2CO3 + Ca(OH)2 --> 2LiOH + CaCO3

A monohydrate LiOH can be produced by evaporation-crystallization.

The utilisation of crystallization technologies provided by Condorchem Envitech can assist during in LiOH production from Li2CO3.

Solution 5. LiOH production by electrodialysis

During electrodialysis (ED) treatment of a Li2SO4 solution, the cathode chamber is enriched with LiOH while the anode one is enriched in H2SO4.

However, other alkali metals like sodium and potassium will also be enriched in the cathode chamber. This could be solved by implementing a crystallization process following ED.

NaOH and KOH solubility is 10 times higher than LiOH solubility. Therefore, it is feasible to precipitate most LiOH while keeping NaOH and KOH in the solution.

The utilisation of crystallization technologies provided by Condorchem Envitech can assist during in LiOH production.

Solution 6. LiCl production

Lithium chloride can be produced by treatment of lithium carbonate with HCl.

Li2CO3 + 2HCI --> 2LiCI + H2CO3

The utilisation of crystallization technologies provided by Condorchem Envitech can facilitate the LiCl production process.

Solution 7. Tailings treatment

A ZLD solution is targeted. Opportunities for water and metals recovery can be available. Reduced effluent volume.

A combination of water and solid waste treatment technologies is required.

The utilisation of membrane and evaporation-based concentration technologies provided by Condorchem Envitech can facilitate a ZLD solution.