A method of treating a wastewater is provided and can be used, for example, to treat a gas well production wastewater to form a wastewater brine. The method can involve crystallizing sodium chloride by evaporation of the wastewater brine with concurrent production of a liquor comprising calcium chloride solution. Bromine and lithium can also be recovered from the liquor in accordance with the teachings of the present invention. Various metal sulfates, such as barium sulfate and strontium sulfate, can be removed from the wastewater in the production of the wastewater brine. Sources of wastewater can include gas well production wastewater and hydrofracture flowback wastewater.

Described herein are methods of recovering lithium from dilute lithium sources. The methods include extracting lithium from an extraction feed using direct lithium extraction in an extraction stage to yield a lithium intermediate, performing one or more concentration operations, each concentration operation concentrating an input stream to yield an output feed, wherein the input stream is obtained from the lithium intermediate and/or the extraction feed is obtained from the output feed. At least one of the concentration operations includes a membrane separation operation having a plurality of reactors in series each having a semi-permeable membrane, such as a counter-flow reverse osmosis operation. Methods may also include generating a low TDS stream as a permeate from any of the one or more concentration operations, wherein the low TDS stream is recycled or used as fresh water.

The invention belongs to the field of bromine recovery from waste circuit board, and particularly relates to a method for recovering high-purity sodium bromide from bromine-containing crude salt. The invention mainly includes the steps of acidification oxidation, multi-stage extraction, and cooperative back extraction. Compared with traditional chlorine oxidation and single urea back extraction technology, the acidification oxidation process can be effectively controlled by reasonable adjustment of the added amount of hydrochloric acid and sodium chlorate, and the tail gas can be absorbed and reused to avoid secondary pollution and resource waste. At the same time, urea is used with sodium carbonate for cooperative back extraction to achieve a high back extraction rate which greatly reduces the amount of urea, and obtains high-purity sodium bromide crystals. The efficient recovery of bromine resources in bromine-containing crude salt is realised. The benefits of the invention are: high product purity, simple operation, environmental friendliness.

A process of producing polylactic acid is provided. The process comprises separating from the crude lactide composition a meso-lactide enriched composition, containing less than 80 mol % of meso-lactide based on a total content of lactide, and a meso-lactide depleted composition. The process comprises polymerizing a polymerization composition comprising meso-lactide and at least one of L-lactide and D-lactide to form a crude polylactic acid composition and devolatilizing the crude polylactic acid composition to produce a purified polylactic acid composition and a composition containing unreacted lactide. The process comprises subjecting the meso-lactide enriched composition to a first purification to produce a purified meso-lactide enriched composition, and subjecting the meso-lactide depleted composition or to a second purification to produce a purified meso-lactide depleted composition. The first and second purifications comprise at least one crystallization step. The polymerization composition contains at least a portion of the purified meso-lactide enriched composition.

A process for the production of lithium carbonate from an aqueous salt solution at least containing lithium ions, chloride ions and calcium ions; the aqueous salt solution with a lithium content of at least 0.005% by weight and a maximum 0.2% by weight is condensed in a first evaporation step at a temperature between 40 C. and 160 C. until a concentrate I with a water content of 70% by weight and >60% by weight is formed. In a second evaporation step, the concentrate I is evaporated at a temperature between 60 C. and 180 C. until a concentrate II with a water content of 60% by weight is formed. In a Li concentration step, the lithium content is raised to at least 0.14% by heating the concentrate II to a temperature of at least 60 C. and thus a lithium-rich concentrate III and a residue III are formed.

The present application provides method for operating a crystallization process model generating device. The method includes receiving selections of a solubility template, a particle size distribution template, a crystallization device template, a process time template, and a concentration factor template provided in a certain order, respectively, performing modeling of a crystallization process model by combining the selected templates, and when the crystallization process model is built, receiving an input of a condition for an injection liquid to perform a simulation for deriving a crystal suspension by inputting the injection liquid into the crystallization process model.

The present invention relates to a lithium compound manufacturing method comprising the steps of heat treatment of lithium-containing ore; roasting the heat-treated ore with sulfuric acid to prepare an acid product; mixing the acid product with leaching water to prepare a leachate; purifying the leachate; and adding a phosphorus supply material and a basic material to the purified leachate to obtain a solid lithium phosphate.

Described herein are methods of recovering lithium from dilute lithium sources. The methods include extracting lithium from an extraction feed using direct lithium extraction in an extraction stage to yield a lithium intermediate, performing one or more concentration operations, each concentration operation concentrating an input stream to yield an output feed, wherein the input stream is obtained from the lithium intermediate and/or the extraction feed is obtained from the output feed. At least one of the concentration operations includes a membrane separation operation having a plurality of reactors in series each having a semi-permeable membrane, such as a counter-flow reverse osmosis operation. Methods may also include generating a low TDS stream as a permeate from any of the one or more concentration operations, wherein the low TDS stream is recycled or used as fresh water.

The present invention relates to a method for treating salt-containing dusts which accumulate during operation of industrial plants, e.g. in waste incineration plants, or during operation of rotary kilns, e.g. in cement production plants or clinker production plants. The method comprises a step a) of forming an aqueous solution by bringing salt-containing dusts into contact with an aqueous phase; a step b) of removing heavy metals from the aqueous solution; and a step c) of separating alkali metal chlorides from the aqueous solution; and the bringing of salt-containing dusts into contact with an aqueous phase in step a) is achieved by means of a multi-stage arrangement through which the salt-containing dusts and the aqueous phase pass in opposite directions.

The present technology relates to processes useful for making crystalline S)-1,1-bis(4-fluorophenyl)propan-2-yl (3-acetoxy-4-methoxypicolinoyl)-L-alaninate (Compound I). Processes disclosed herein describe more stable, storage compatible preparations of Compound I. Also disclosed are preparations of Compound I which have fewer (trace) impurities.