A method for recovering lithium from low-content extraction tailwater and recycling extraction tailwater is provided. The disclosure is characterized that recovery of lithium from lithium-containing extraction tailwater is achieved by adding calcium to remove fluorine, carrying out evaporative crystallization and precipitating lithium salts. Recycle of extraction tailwater is achieved by adopting the following steps: in the lithium-containing extraction tailwater, adding calcium to remove fluorine, carrying out evaporative crystallization, recovering condensate water, precipitating a lithium salt and recycling mother liquor. According to the disclosure, lithium is recovered from low-content extraction tailwater via enrichment and sodium sulfate and distilled water therein are incidentally recovered, so that zero release of battery waste treatment wastewater is achieved.

A method for recovering lithium from low-content extraction tailwater and recycling extraction tailwater is provided. The disclosure is characterized that recovery of lithium from lithium-containing extraction tailwater is achieved by adding calcium to remove fluorine, carrying out evaporative crystallization and precipitating lithium salts. Recycle of extraction tailwater is achieved by adopting the following steps: in the lithium-containing extraction tailwater, adding calcium to remove fluorine, carrying out evaporative crystallization, recovering condensate water, precipitating a lithium salt and recycling mother liquor. According to the disclosure, lithium is recovered from low-content extraction tailwater via enrichment and sodium sulfate and distilled water therein are incidentally recovered, so that zero release of battery waste treatment wastewater is achieved.

Systems and methods for producing potassium sulfate. Such a method involves providing an industrial waste material that includes at least one metal sulfate or a metal product that has been reacted with sulfuric acid to produce metal sulfates, and then reacting the metal sulfate with potassium carbonate to produce a byproduct that contains potassium sulfate.

Systems and methods for producing potassium sulfate. Such a method involves providing an industrial waste material that includes at least one metal sulfate or a metal product that has been reacted with sulfuric acid to produce metal sulfates, and then reacting the metal sulfate with potassium carbonate to produce a byproduct that contains potassium sulfate.

Provided herein is a process for producing one or more products from a lignocellulosic feedstock. The process comprises treating the lignocellulosic feedstock by contacting the feedstock at least sulfur dioxide, sulfurous acid, or a combination thereof to produce a pretreated feedstock comprising one or more sulfonic acids. A process stream comprising one or more sulfonic acids is subsequently treated in a wet oxidation step to produce a stream comprising at least soluble oxidized phenolic compounds. The soluble oxidized phenolic compounds are then fed to an anaerobic digestion to produce methane. Optionally, hydrogen sulfide is produced during the anaerobic digestion. The hydrogen sulfide may then be converted to an acid selected from sulfur dioxide, sulfurous acid or a combination thereof in one or more steps. The acid may then be re-used in treatment as desired.

Provided herein is a process for producing one or more products from a lignocellulosic feedstock. The process comprises treating the lignocellulosic feedstock by contacting the feedstock at least sulfur dioxide, sulfurous acid, or a combination thereof to produce a pretreated feedstock comprising one or more sulfonic acids. A process stream comprising one or more sulfonic acids is subsequently treated in a wet oxidation step to produce a stream comprising at least soluble oxidized phenolic compounds. The soluble oxidized phenolic compounds are then fed to an anaerobic digestion to produce methane. Optionally, hydrogen sulfide is produced during the anaerobic digestion. The hydrogen sulfide may then be converted to an acid selected from sulfur dioxide, sulfurous acid or a combination thereof in one or more steps. The acid may then be re-used in treatment as desired.

The invention relates to a process for dehumidifying a moist gas mixture. The invention further relates to an apparatus for dehumidifying a moist gas mixture and to the use of said apparatus in the process according to the invention.

The invention relates to a method for producing sulphate of potash granulates, wherein 0.1 to 7.5 wt % of a sodium salt selected from among sodium chloride, sodium sulphate, sodium sulphate hydrates, sodium hydroxide and mixtures thereof are added to the sulphate of potash during the granulation process, the percentage by weight being in relation to the sulphate of potash used. In addition, 0.1 to 2.5 wt % of water are added prior to or during the granulation process. The invention also relates to the granulates obtained by said method as well as the use of sodium salts and glaserite and mixtures thereof for improving the mechanical properties of sulfate of potash granulates. The sulphate of potash granulates produced by the method of the invention have significantly greater bursting strength and significantly greater abrasion resistance than granulates known from the prior art.

A process for producing one or more products from a lignocellulosic feedstock comprising treating the lignocellulosic feedstock to produce sugar in one or more stages comprising addition of acid, base or a combination thereof and introduction of heat. The addition of the acid, base, or a combination thereof produces a salt. The sugar is fermented to produce a fermentation product and the fermentation product is recovered. A stream comprising the salt is treated by wet oxidation with the introduction of heat. A stream comprising salt resulting from the wet oxidation is provided for use as a salt product or a process chemical for introduction within the process. Heat from the wet oxidation may be supplied to any stage of the process in which heat is introduced.

A process for producing one or more products from a lignocellulosic feedstock comprising treating the lignocellulosic feedstock to produce sugar in one or more stages comprising addition of acid, base or a combination thereof and introduction of heat. The addition of the acid, base, or a combination thereof produces a salt. The sugar is fermented to produce a fermentation product and the fermentation product is recovered. A stream comprising the salt is treated by wet oxidation with the introduction of heat. A stream comprising salt resulting from the wet oxidation is provided for use as a salt product or a process chemical for introduction within the process. Heat from the wet oxidation may be supplied to any stage of the process in which heat is introduced.