This invention relates generally to a process for selective adsorption and recovery of lithium from natural and synthetic brines, and more particular to a process for recovering lithium from a natural or synthetic brine solution by passing the brine solution through a lithium selective adsorbent in a continuous countercurrent adsorption and desorption circuit.

A process (10) for the treatment of a lithium containing material (12), the process comprising the steps of: (i) Preparing a process solution from the lithium containing material (12); (ii) Passing the process solution from step (i) to a series of impurity removal steps, one of which is an HCl sparging step 58, thereby providing a substantially purified lithium chloride solution; and (iii) Passing the purified lithium chloride solution of step (ii) to an electrolysis step (70) thereby producing a lithium hydroxide solution.

An additional step in which the lithium hydroxide solution produced in step (iii) is carbonated by passing compressed carbon dioxide (88) through the solution, thereby producing a lithium carbonate precipitate, is also disclosed.

A process (10) for the treatment of a lithium containing material (12), the process comprising the steps of: (i) Preparing a process solution from the lithium containing material (12); (ii) Passing the process solution from step (i) to a series of impurity removal steps, one of which is an HCl sparging step 58, thereby providing a substantially purified lithium chloride solution; and (iii) Passing the purified lithium chloride solution of step (ii) to an electrolysis step (70) thereby producing a lithium hydroxide solution.

An additional step in which the lithium hydroxide solution produced in step (iii) is carbonated by passing compressed carbon dioxide (88) through the solution, thereby producing a lithium carbonate precipitate, is also disclosed.

The secondary amide contained in the extraction system consists of a single compound or a mixture of two or more compounds, wherein R.sub.1 is selected from a C2˜C12 alkyl, or a C3˜C12 cycloalkyl containing a single-ring structure, R.sub.2 is selected from a C1˜C11 alkyl, or a C3˜C11 cycloalkyl containing a single-ring structure; the total number of carbon atoms in the molecule is 12˜18. With a volume ratio of an organic phase and a brine phase being 1˜10:1, at a brine density of 1.25˜1.38 g/cm.sup.3 and at a temperature of 0˜50° C., a single-stage or multi-stage countercurrent extraction and a stripping are conducted to obtain a water phase with a low magnesium-lithium ratio, which is subjected to concentration, impurity removal and preparation to get lithium chloride, lithium carbonate and lithium hydroxide respectively. Water is used for stripping, greatly reducing the consumption of acid and base, and the separation process is shortened.

The secondary amide contained in the extraction system consists of a single compound or a mixture of two or more compounds, wherein R.sub.1 is selected from a C2˜C12 alkyl, or a C3˜C12 cycloalkyl containing a single-ring structure, R.sub.2 is selected from a C1˜C11 alkyl, or a C3˜C11 cycloalkyl containing a single-ring structure; the total number of carbon atoms in the molecule is 12˜18. With a volume ratio of an organic phase and a brine phase being 1˜10:1, at a brine density of 1.25˜1.38 g/cm.sup.3 and at a temperature of 0˜50° C., a single-stage or multi-stage countercurrent extraction and a stripping are conducted to obtain a water phase with a low magnesium-lithium ratio, which is subjected to concentration, impurity removal and preparation to get lithium chloride, lithium carbonate and lithium hydroxide respectively. Water is used for stripping, greatly reducing the consumption of acid and base, and the separation process is shortened.

The extraction system contains secondary amides and alkyl alcohols which are separately used as the extractants for extracting lithium and boron and consist of a single compound or a mixture of two or more compounds, and the total number of carbon atoms in their molecules are 12˜18 and 8˜20 respectively; the extraction system has a freezing point less than 0° C. With a volume ratio of an organic phase and a brine phase being 1˜10:1, at a brine density of 1.25˜1.38 g/cm.sup.3, at a brine pH value of 0˜7 and at a temperature of 0˜50° C., a single-stage or multi-stage countercurrent extraction and a stripping are conducted to obtain a water phase with a low magnesium-lithium ratio, which is subjected to concentration, impurity removal and preparation to get lithium chloride, lithium carbonate, lithium hydroxide and boric acid respectively. Water is used for stripping, greatly reducing the consumption of acid and base.

The extraction system contains secondary amides and alkyl alcohols which are separately used as the extractants for extracting lithium and boron and consist of a single compound or a mixture of two or more compounds, and the total number of carbon atoms in their molecules are 12˜18 and 8˜20 respectively; the extraction system has a freezing point less than 0° C. With a volume ratio of an organic phase and a brine phase being 1˜10:1, at a brine density of 1.25˜1.38 g/cm.sup.3, at a brine pH value of 0˜7 and at a temperature of 0˜50° C., a single-stage or multi-stage countercurrent extraction and a stripping are conducted to obtain a water phase with a low magnesium-lithium ratio, which is subjected to concentration, impurity removal and preparation to get lithium chloride, lithium carbonate, lithium hydroxide and boric acid respectively. Water is used for stripping, greatly reducing the consumption of acid and base.

Systems and methods using solar evaporation to preconcentrate lithium containing brines to at or near lithium saturation, followed by a separation processes to separate lithium from impurities. A separated impurity stream is recycled to a point in the evaporation sequence where conditions are favorable for their precipitation and removal or disposed in a separate evaporation pond or reinjected underground, while a lower impurity stream is transferred to one or more of the removal location, to a subsequent pond in the sequence, or to a lithium plant or concentration facility. Further concentration of lithium by evaporation can then take place because impurities are removed thus eliminating lithium losses due to co-precipitation and achieving significantly higher concentrations of lithium.

The present invention relates to a method for producing a lithium halide compound, capable of industrially advantageously producing a lithium halide compound having a low water content, particularly lithium bromide and lithium iodide, at a high reaction efficiency without accompanying a step of directly removing water, and the method including mixing lithium sulfide, a halogen molecule of at least one of bromine and iodine, and a first solvent; and removing the first solvent, wherein the first solvent is a solvent that dissolves a lithium halide containing the same halogen element as the halogen molecule.

The present invention relates to a method for producing a lithium halide compound, capable of industrially advantageously producing a lithium halide compound having a low water content, particularly lithium bromide and lithium iodide, at a high reaction efficiency without accompanying a step of directly removing water, and the method including mixing lithium sulfide, a halogen molecule of at least one of bromine and iodine, and a first solvent; and removing the first solvent, wherein the first solvent is a solvent that dissolves a lithium halide containing the same halogen element as the halogen molecule.