Impurity removal from brines pre/post direct lithium extraction

A method of reducing impurities in a brine stream, comprising:

• exposing a brine stream comprising one or more impurities to a first precipitation reagent to produce a first precipitate comprising a first amount of a first type of impurity of the one or more impurities and a first intermediate brine stream comprising a residual amount of the first type of impurity of the one or more impurities;
• filtering a second amount of the first type of impurity of the one or more impurities from the first intermediate brine stream or a derivative thereof in a first membrane separation unit to produce a second intermediate brine stream;
• exposing the second intermediate brine stream or a derivative thereof to a second precipitation reagent to produce a second precipitate comprising a first amount of a second type of impurity of the one or more impurities and a third intermediate brine stream comprising a residual amount of the second type of impurity of the one or more impurities;
• and
• filtering a second amount of the second type of impurity of the one or more impurities from the third intermediate brine stream or a derivative thereof in a second membrane separation unit to produce a purified brine stream, wherein the one or more impurities comprise one or more multivalent metal cations, silica, boron, or a combination thereof.

A method of reducing impurities in a brine stream, comprising:

• exposing a brine stream comprising one or more impurities to a first precipitation reagent to produce a first precipitate comprising a first amount of a first type of impurity of the one or more impurities and a first intermediate brine stream comprising a residual amount of the first type of impurity of the one or more impurities;
• exposing the first intermediate brine stream or a derivative thereof to a second precipitation reagent to produce a second precipitate comprising a first amount of a second type of impurity of the one or more impurities and a second intermediate brine stream comprising a residual amount of both the first type of impurity and the second type of impurity;
• and
• filtering a second amount of the first type of impurity and a second amount of the second type of impurity from the second intermediate brine stream or a derivative thereof in one or more membrane separation units to produce a purified brine stream, wherein the one or more impurities comprise one or more multivalent metal cations, silica, boron, or a combination thereof.