A process for the work-up of salt-containing process water which contains an alkali metal chloride as salt in a concentration of at least 4% by weight and organic or inorganic and organic impurities from chemical production processes and reuse of the salt by a combination of prepurification and concentration, crystallization and purification of the salt and optionally subsequently use of the salt in an electrolysis for producing basic chemicals are described.

A method and system for rapidly preparing lithium carbonate or concentrated brine using high-temperature steam. The method comprises the steps of: feeding brine into a reactor, heating the brine with high-temperature steam above 200° C. while simultaneously discharging steam produced in the reactor, cooling and condensing the discharged steam in a condenser and collecting the condensate, and stopping the high-temperature steam after the brine is concentrated to a predetermined concentration or after a sufficient amount of lithium carbonate is collected. The system comprises: a reactor provided with a brine inlet, a steam outlet connected to a condenser, a product outlet, and a plurality of steam pipes. The method concerns the direct heating of brine using high-temperature steam, which is effective and efficient, and also produces fresh water. The heating is uniform and rapid, and does not require jackets, heat exchange tubes, mixers and vacuum pumps, vastly simplifying the system.

A method and system for rapidly preparing lithium carbonate or concentrated brine using high-temperature steam. The method comprises the steps of: feeding brine into a reactor, heating the brine with high-temperature steam above 200° C. while simultaneously discharging steam produced in the reactor, cooling and condensing the discharged steam in a condenser and collecting the condensate, and stopping the high-temperature steam after the brine is concentrated to a predetermined concentration or after a sufficient amount of lithium carbonate is collected. The system comprises: a reactor provided with a brine inlet, a steam outlet connected to a condenser, a product outlet, and a plurality of steam pipes. The method concerns the direct heating of brine using high-temperature steam, which is effective and efficient, and also produces fresh water. The heating is uniform and rapid, and does not require jackets, heat exchange tubes, mixers and vacuum pumps, vastly simplifying the system.

Salt production can include preparing hydrohalite particles by crystallization from saturated brine, adding the hydrohalite particles to a salt brine, thereby forming a hydrohalite-salt brine mixture, agitating the hydrohalite-salt brine mixture until the hydrohalite particles have decomposed into NaCl crystals, and filtering out the NaCl crystals from the salt brine. In some instances, an initial temperature of the salt brine prior to adding the hydrohalite particles is at least 0° C. In some instances, a ratio of salt brine to hydrohalite particles, by weight, is from 0.4 to 29.

Salt production can include preparing hydrohalite particles by crystallization from saturated brine, adding the hydrohalite particles to a salt brine, thereby forming a hydrohalite-salt brine mixture, agitating the hydrohalite-salt brine mixture until the hydrohalite particles have decomposed into NaCl crystals, and filtering out the NaCl crystals from the salt brine. In some instances, an initial temperature of the salt brine prior to adding the hydrohalite particles is at least 0° C. In some instances, a ratio of salt brine to hydrohalite particles, by weight, is from 0.4 to 29.

A system and method for producing minerals from divalent ion-containing brine stream includes rejecting sulfate from a divalent-ion rich reject stream in a first nanofiltration seawater reverse osmosis (NF-SWRO) unit, producing solid calcium sulfate dihydrate and a magnesium-rich brine stream in a first concentration unit, concentrating the magnesium-rich brine stream to a saturation point of sodium chloride in a second concentration unit, producing solid sodium chloride and a supernatant product stream in a first crystallizing unit, produce a concentrated magnesium-rich bittern stream from the supernatant product stream in a third concentration unit, and at least one of producing hydrated magnesium chloride from the concentrated magnesium-rich bittern stream in a second crystallizing unit and producing anhydrous magnesium chloride by prilling the concentrated magnesium-rich bitterns stream under a hydrogen chloride atmosphere in a dry air process unit.

A water evaporation system includes an evaporation module configured to evaporate water from a brine; a support module attached to the evaporation module and configured to support the evaporation module above the brine; and an inlet configured to add a crystal growth inhibitor to the brine.

A water evaporation system includes an evaporation module configured to evaporate water from a brine; a support module attached to the evaporation module and configured to support the evaporation module above the brine; and an inlet configured to add a crystal growth inhibitor to the brine.

A method for preparing potassium chloride from carnallite includes: carrying out high-temperature water solution mining treatment on carnallite with fresh water to obtain potassium-rich saturated brine; mixing the potassium-rich saturated brine, a sylvine saturated solution, and bittern for mixing brine, evaporation and decomposition to obtain artificial sylvine; and carrying out low-temperature selective dissolution treatment on the artificial sylvine with fresh water to prepare potassium chloride. The carnallite is mined by using hot water, which reduces the content of sodium chloride in the potassium-rich saturated brine; artificial sylvine is only subjected to low-temperature selective dissolution once, which avoids unnecessary energy consumption and impurity accumulation unnecessary for multifold cycles of thermal dissolution-cold crystallization treatment of sylvine while guaranteeing the high yield and high quality of potassium chloride. The method is suitable for different grades of carnallite, has extremely strong adaptability and loose technical conditions, and is conducive to promotion and implementation.

A method for preparing potassium chloride from carnallite includes: carrying out high-temperature water solution mining treatment on carnallite with fresh water to obtain potassium-rich saturated brine; mixing the potassium-rich saturated brine, a sylvine saturated solution, and bittern for mixing brine, evaporation and decomposition to obtain artificial sylvine; and carrying out low-temperature selective dissolution treatment on the artificial sylvine with fresh water to prepare potassium chloride. The carnallite is mined by using hot water, which reduces the content of sodium chloride in the potassium-rich saturated brine; artificial sylvine is only subjected to low-temperature selective dissolution once, which avoids unnecessary energy consumption and impurity accumulation unnecessary for multifold cycles of thermal dissolution-cold crystallization treatment of sylvine while guaranteeing the high yield and high quality of potassium chloride. The method is suitable for different grades of carnallite, has extremely strong adaptability and loose technical conditions, and is conducive to promotion and implementation.