A method of improving rheological properties of a divalent brine based downhole treatment fluid at an elevated temperature comprises adding to the divalent brine based downhole treatment fluid a rheological modifier, which comprises a carboxylic acid ester, or a phosphate ester blended with an ethoxylated glycol, or a combination comprising at least one of the foregoing in an amount effective to improve the rheological properties of the divalent brine based downhole treatment fluid at a temperature of greater than about 200° F. The divalent brine based downhole treatment fluid comprises calcium bromide, calcium chloride, zinc bromide, zinc chloride, or a combination comprising at least one of the foregoing.

A solvent extraction process for recovering bromide from a sulfate-containing aqueous stream, the process comprises an extraction step wherein said aqueous stream is mixed with an extraction medium comprising a tertiary amine extractant dissolved in one or more water-immiscible organic solvents, wherein said mixing is carried out in a strongly acidic environment, thereby forming bromide-containing extract and a raffinate with a reduced bromide level, wherein the bromide-containing extract is optionally treated to further minimize the presence of sulfate and is subsequently combined with an aqueous calcium source to form calcium bromide.

A solvent extraction process for recovering bromide from a sulfate-containing aqueous stream, the process comprises an extraction step wherein said aqueous stream is mixed with an extraction medium comprising a tertiary amine extractant dissolved in one or more water-immiscible organic solvents, wherein said mixing is carried out in a strongly acidic environment, thereby forming bromide-containing extract and a raffinate with a reduced bromide level, wherein the bromide-containing extract is optionally treated to further minimize the presence of sulfate and is subsequently combined with an aqueous calcium source to form calcium bromide.

A method of improving rheological properties of a divalent brine based downhole treatment fluid at an elevated temperature comprises adding to the divalent brine based downhole treatment fluid a rheological modifier, which comprises a carboxylic acid ester, or a phosphate ester blended with an ethoxylated glycol, or a combination comprising at least one of the foregoing in an amount effective to improve the rheological properties of the divalent brine based downhole treatment fluid at a temperature of greater than about 200° F. The divalent brine based downhole treatment fluid comprises calcium bromide, calcium chloride, zinc bromide, zinc chloride, or a combination comprising at least one of the foregoing.

A method of improving rheological properties of a divalent brine based downhole treatment fluid at an elevated temperature comprises adding to the divalent brine based downhole treatment fluid a rheological modifier, which comprises a carboxylic acid ester, or a phosphate ester blended with an ethoxylated glycol, or a combination comprising at least one of the foregoing in an amount effective to improve the rheological properties of the divalent brine based downhole treatment fluid at a temperature of greater than about 200° F. The divalent brine based downhole treatment fluid comprises calcium bromide, calcium chloride, zinc bromide, zinc chloride, or a combination comprising at least one of the foregoing.

A method of improving rheological properties of a divalent brine based downhole treatment fluid at an elevated temperature comprises adding to the divalent brine based downhole treatment fluid a rheological modifier, which comprises a carboxylic acid ester, or a phosphate ester blended with an ethoxylated glycol, or a combination comprising at least one of the foregoing in an amount effective to improve the rheological properties of the divalent brine based downhole treatment fluid at a temperature of greater than about 200 F. The divalent brine based downhole treatment fluid comprises calcium bromide, calcium chloride, zinc bromide, zinc chloride, or a combination comprising at least one of the foregoing.

A method of improving rheological properties of a divalent brine based downhole treatment fluid at an elevated temperature comprises adding to the divalent brine based downhole treatment fluid a rheological modifier, which comprises a carboxylic acid ester, or a phosphate ester blended with an ethoxylated glycol, or a combination comprising at least one of the foregoing in an amount effective to improve the rheological properties of the divalent brine based downhole treatment fluid at a temperature of greater than about 200 F. The divalent brine based downhole treatment fluid comprises calcium bromide, calcium chloride, zinc bromide, zinc chloride, or a combination comprising at least one of the foregoing.

A method of improving rheological properties of a divalent brine based downhole treatment fluid at an elevated temperature comprises adding to the divalent brine based downhole treatment fluid a rheological modifier, which comprises a carboxylic acid ester, or a phosphate ester blended with an ethoxylated glycol, or a combination comprising at least one of the foregoing in an amount effective to improve the rheological properties of the divalent brine based downhole treatment fluid at a temperature of greater than about 200 F. The divalent brine based downhole treatment fluid comprises calcium bromide, calcium chloride, zinc bromide, zinc chloride, or a combination comprising at least one of the foregoing.

Recovering bromine from solid waste containing bromine compounds, and applications thereof, such as for recovering bromine in a form suitable for reuse, or for manufacturing bromine salt (for example, calcium bromide). Bromine recovery method and system include: providing and mixing (i) solid waste containing bromine compounds and (ii) solid calcium hydroxide; heating the mixture in a chemical reducing (non-oxidizing) environment, thereby forming heated product consisting essentially of only solid calcium bromide (salt); and processing the heated product, to form bromine. Calcium bromide manufacturing method and system include: providing and mixing (i) solid waste containing bromine compounds and (ii) solid calcium hydroxide; heating the mixture in a chemical reducing (non-oxidizing) environment, thereby forming solid calcium bromide (salt). Applicable to processes of, or involving, manufacturing bromine-based flame (fire) retardant materials.

Recovering bromine from solid waste containing bromine compounds, and applications thereof, such as for recovering bromine in a form suitable for reuse, or for manufacturing bromine salt (for example, calcium bromide). Bromine recovery method and system include: providing and mixing (i) solid waste containing bromine compounds and (ii) solid calcium hydroxide; heating the mixture in a chemical reducing (non-oxidizing) environment, thereby forming heated product consisting essentially of only solid calcium bromide (salt); and processing the heated product, to form bromine. Calcium bromide manufacturing method and system include: providing and mixing (i) solid waste containing bromine compounds and (ii) solid calcium hydroxide; heating the mixture in a chemical reducing (non-oxidizing) environment, thereby forming solid calcium bromide (salt). Applicable to processes of, or involving, manufacturing bromine-based flame (fire) retardant materials.