This invention relates to a method for the preparation of lithium carbonate from lithium chloride containing brines. The method can include a silica removal step, capturing lithium chloride, recovering lithium chloride, supplying lithium chloride to an electrochemical cell and producing lithium hydroxide, contacting the lithium hydroxide with carbon dioxide to produce lithium carbonate.

This invention relates to a method for the preparation of lithium carbonate from lithium chloride containing brines. The method can include a silica removal step, capturing lithium chloride, recovering lithium chloride, supplying lithium chloride to an electrochemical cell and producing lithium hydroxide, contacting the lithium hydroxide with carbon dioxide to produce lithium carbonate.

The present disclosure relates to a method for producing, high-purity lithium hydroxide from a lithium-containing waste liquid of a spent lithium secondary battery.

The present disclosure relates to a method for producing, high-purity lithium hydroxide from a lithium-containing waste liquid of a spent lithium secondary battery.

In a recovery method for a lithium precursor according to embodiments of the present invention, a cathode active material mixture including a lithium composite oxide is prepared. The cathode active material mixture is reacted with a carbon-based solid material in an atmosphere of an inert gas to form a preliminary precursor mixture containing lithium oxide. A washing treatment of the preliminary precursor mixture is performed to separate a lithium precursor. The lithium precursor can be recovered with high yield and high efficiency.

A capacitive deionization process is provided. The capacitive deionization process includes a charging step of applying power to a capacitive deionization apparatus in a charging state and supplying charge water containing target dissolved ions to be precipitated to the capacitive deionization apparatus for a predetermined period of time, a discharging step of applying power to the capacitive deionization apparatus in a discharging state and supplying discharge water in which the target dissolved ions are in a saturated state to the capacitive deionization apparatus for a predetermined period of time, and a crystal recovery step of recovering a crystal of the target dissolved ions precipitated in the capacitive deionization apparatus and/or the discharge water.

A capacitive deionization process is provided. The capacitive deionization process includes a charging step of applying power to a capacitive deionization apparatus in a charging state and supplying charge water containing target dissolved ions to be precipitated to the capacitive deionization apparatus for a predetermined period of time, a discharging step of applying power to the capacitive deionization apparatus in a discharging state and supplying discharge water in which the target dissolved ions are in a saturated state to the capacitive deionization apparatus for a predetermined period of time, and a crystal recovery step of recovering a crystal of the target dissolved ions precipitated in the capacitive deionization apparatus and/or the discharge water.

Lithium recovery processes are described using concentration and conversion techniques. A vaporizer or membrane can be used to concentrate lithium and precipitate impurities. A conversion process can be used to replace anions in lithium bearing streams by adding a second anion and precipitating lithium in a salt with the second anion. Rotary separation can be used to separate the precipitated lithium salt.

Lithium recovery processes are described using concentration and conversion techniques. A vaporizer or membrane can be used to concentrate lithium and precipitate impurities. A conversion process can be used to replace anions in lithium bearing streams by adding a second anion and precipitating lithium in a salt with the second anion. Rotary separation can be used to separate the precipitated lithium salt.

A method of heat-treating a waste cathode material to recover lithium carbonate from the waste cathode material, and a lithium carbonate recovery method using the waste cathode material heat treatment method are provided. The method of heat-treating the waste cathode material includes heating an interior of a heat treatment furnace by burning a hydrocarbon fluid in the heat treatment furnace and producing lithium carbonate (Li.sub.2CO.sub.3) and residual metal oxide by reacting a waste cathode material in the heat treatment furnace with CO.sub.2 generated during burning of the hydrocarbon fluid.