Method for the extraction of lithium

A method for the extraction of lithium from a lithium bearing material containing alpha spodumene, the method comprising:

• converting at least a portion of the alpha spodumene present in the lithium bearing material to beta spodumene;
• subjecting the lithium bearing material to a leaching process at an elevated pressure in the presence of potassium carbonate to produce a leaching slurry containing lithium carbonate;
• performing a carbonation process on the leaching slurry to convert at least a portion of the lithium carbonate to lithium bicarbonate;
• performing a solid-liquid separation process on the leaching slurry to separate a leach residue from the leaching solution;
• precipitating lithium carbonate from the leaching solution;
• and
• separating precipitated lithium carbonate from the leaching solution.

A method for the extraction of lithium from a lithium bearing material containing alpha spodumene, the method comprising:

• converting at least a portion of the alpha spodumene present in the lithium bearing material to beta spodumene;
• subjecting the lithium bearing material to a first leaching process at an elevated pressure in the presence of potassium carbonate to precipitate lithium carbonate;
• subjecting the lithium carbonate to a second leaching process in the presence of hydroxide ions to produce a leaching solution containing an aqueous solution of lithium hydroxide;
• separating a solid leach residue from the leaching solution to produce a concentrated lithium hydroxide solution;
• and
• producing a solid lithium hydroxide product from the concentrated lithium hydroxide solution.

A method for the extraction of lithium from a lithium bearing material containing alpha spodumene, the method comprising:

• converting at least a portion of the alpha spodumene present in the lithium bearing material to beta spodumene;
• subjecting the lithium bearing material to a leaching process at an elevated temperature in the presence of potassium carbonate to produce a leaching slurry containing lithium carbonate;
• performing a carbon dioxide leaching process on the leaching slurry to produce a bicarbonate leaching slurry in which at least a portion of the lithium carbonate is converted to lithium bicarbonate;
• performing a solid-liquid separation process on the bicarbonate leaching slurry to separate a leach residue from a leaching solution;
• precipitating lithium carbonate from the leaching solution;
• and
• separating precipitated lithium carbonate from the leaching solution.

A method for the extraction of lithium from a lithium bearing material containing alpha spodumene, the method comprising:

• converting at least a portion of the alpha spodumene present in the lithium bearing material to beta spodumene;
• subjecting the lithium bearing material to a first leaching process at an elevated pressure in the presence of potassium carbonate to produce a leaching slurry containing lithium carbonate;
• performing a carbon dioxide leaching process on the leaching slurry to produce a bicarbonate leaching slurry in which at least a portion of the lithium carbonate is converted to lithium bicarbonate;
• performing a solid-liquid separation process on the bicarbonate leaching slurry to separate a leach residue from a leaching solution;
• precipitating lithium carbonate from the separated leaching solution;
• and
• separating precipitated lithium carbonate from the leaching solution.

A method for the extraction of lithium from a lithium bearing material comprising spodumene, the method comprising:

• converting at least a portion of the alpha spodumene present in the lithium bearing material to beta spodumene;
• subjecting the lithium bearing material to a quenching process to generate a slurry of lithium bearing material;
• subjecting the slurry to a size reduction process to generate relatively fine particles;
• and
• subjecting the relatively fine particles to a leaching process at a pressure of greater than 2500 kPa and a temperature of greater than 250° C. but less than 300° C. in the presence of potassium carbonate to produce a leaching slurry containing lithium carbonate.