A process (10) for the production of lithium hydroxide, the process comprising the steps of: (i) Causticising lithium chloride (12) with sodium hydroxide (16) to produce a lithium hydroxide product; (ii) Collecting the solids resulting from the causticisation of step (i) and filtering (22) same; (iii) The filtered solids from step (ii) are passed to a heating step (32) in which anhydrous lithium hydroxide is produced; (iv) Filtering (34) the anhydrous lithium hydroxide product of step (iii); and (v) Quenching the anhydrous lithium hydroxide of step (iv) with water to produce lithium hydroxide monohydrate crystals.

A harmless treatment and regeneration device and method thereof of waste liquid discharge from failed hardener solution during hardening of water glass mold shell via ammonium chloride solution are provided. The device includes a waste liquid storage tank, a filtering mechanism, a regeneration mechanism, and a regeneration liquid storage tank. A fluid outlet end of the waste liquid storage tank is in fluid communication with a fluid inlet end of the filtering mechanism, a fluid outlet end of the filtering mechanism is in fluid communication with a fluid inlet end of the regeneration mechanism, and a fluid outlet end of the regeneration mechanism is in fluid communication with a fluid inlet end of the regeneration liquid storage tank.

A harmless treatment and regeneration device and method thereof of waste liquid discharge from failed hardener solution during hardening of water glass mold shell via ammonium chloride solution are provided. The device includes a waste liquid storage tank, a filtering mechanism, a regeneration mechanism, and a regeneration liquid storage tank. A fluid outlet end of the waste liquid storage tank is in fluid communication with a fluid inlet end of the filtering mechanism, a fluid outlet end of the filtering mechanism is in fluid communication with a fluid inlet end of the regeneration mechanism, and a fluid outlet end of the regeneration mechanism is in fluid communication with a fluid inlet end of the regeneration liquid storage tank.

A process for manufacturing an aqueous sodium chloride solution and the use of such solution for the manufacturing of crude sodium bicarbonate from SOLVAY ammonia process or for the manufacturing of soda ash, comprising the steps of: a) dispersing a first solid material comprising sodium chloride, sodium carbonate, and sodium sulfate, and a second solid material comprising calcium chloride in an aqueous liquid to produce an aqueous medium; b) subjecting the aqueous medium to clarification to produce a clarified aqueous medium; and c) recovering the clarified aqueous medium as aqueous sodium chloride solution; wherein a weight L/S ratio between the weight of the aqueous liquid used to produce the aqueous medium and the total weight of the first solid material and the second solid material is in the range of from 0.7 to 3.5.

A process for manufacturing an aqueous sodium chloride solution and the use of such solution for the manufacturing of crude sodium bicarbonate from SOLVAY ammonia process or for the manufacturing of soda ash, comprising the steps of: a) dispersing a first solid material comprising sodium chloride, sodium carbonate, and sodium sulfate, and a second solid material comprising calcium chloride in an aqueous liquid to produce an aqueous medium; b) subjecting the aqueous medium to clarification to produce a clarified aqueous medium; and c) recovering the clarified aqueous medium as aqueous sodium chloride solution; wherein a weight L/S ratio between the weight of the aqueous liquid used to produce the aqueous medium and the total weight of the first solid material and the second solid material is in the range of from 0.7 to 3.5.

The disclosed technology includes a method for producing ultrafine alumina from salt slag waste generated in aluminum recycling useful in the manufacture of durable ceramic products; a system for recovering alumina from salt slag waste; a method and systems for recovering salts, aluminum and alumina from salt slag waste; and a method and systems of capturing ammonia in a process recovering salts, aluminum and alumina from salt slag waste. The methods and systems provided crush the dry particles of the salt slag waste, scrub the slag with water, and with steam and by means of a vented alumina press, dewater the scrubbed slag particles. In some methods and systems of the disclosed technology, the particles of the pressed alumina cake are further reduced. In some methods and systems, the salt in the salt effluent is crystalized. In some methods and systems of the disclosed technology, the ammonia is contained and captured.

The disclosed technology includes a method for producing ultrafine alumina from salt slag waste generated in aluminum recycling useful in the manufacture of durable ceramic products; a system for recovering alumina from salt slag waste; a method and systems for recovering salts, aluminum and alumina from salt slag waste; and a method and systems of capturing ammonia in a process recovering salts, aluminum and alumina from salt slag waste. The methods and systems provided crush the dry particles of the salt slag waste, scrub the slag with water, and with steam and by means of a vented alumina press, dewater the scrubbed slag particles. In some methods and systems of the disclosed technology, the particles of the pressed alumina cake are further reduced. In some methods and systems, the salt in the salt effluent is crystalized. In some methods and systems of the disclosed technology, the ammonia is contained and captured.

Although U.S. Pat. No. 8,182,784 teaches the recovery of potassium chloride from schoenite end liquor (SEL) using dipicrylamine as extractant, and consequently simplifies the recovery of sulphate of potash (SOP) from kainite mixed salt employing the scheme disclosed in U.S. Pat. No. 7,041,268, the hazards associated with this extractant have thwarted practical utilization of the invention. Many other extractants for potash recovery have been disclosed in the prior art but none has been found suitable so far for practical exploitation. It is disclosed herein that the bitartrate ion, and particularly L-bitartrate, precipitates out potassium bitartrate very efficiently from SEL with ca. 90% utilization of the extractant. In contrast, recovery of potassium bi-tartrate from sea bittern directly is relatively much lower. It is further disclosed that this precipitate can be treated with magnesium hydroxide and magnesium chloride to throw out magnesium tartrate with ca. 90% recovery while yielding a nearly saturated solution of potassium chloride which can be utilized for the reaction with schoenite to obtain SOP. It is further demonstrated that the magnesium tartrate can be treated with an appropriate amount of aqueous HCl and added into a subsequent batch of SEL to throw out potassium bitartrate once again which demonstrates the recyclability of the extractant. The overall loss of tartrate over a cycle was ca. 20% but the dissolved tartrate remaining in the K-depleted SEL and KCl solutions can be precipitated out as calcium tartrate from which tartaric acid can be recovered by known methods, curtailing thereby the loss of tartaric acid per kg of KCl to <5 g. It is also demonstrated that through a similar approach, seaweed sap containing ca. 4% KCl can be concentrated to 20-22% KCl, with excellent utilization efficiency of tartaric acid, and this solution can similarly be utilized for SOP preparation. Potassium salts bearing other anions such as sulphate, nitrate, phosphate and carbonate can also be prepared from the isolated potassium bitartrate.

Although U.S. Pat. No. 8,182,784 teaches the recovery of potassium chloride from schoenite end liquor (SEL) using dipicrylamine as extractant, and consequently simplifies the recovery of sulphate of potash (SOP) from kainite mixed salt employing the scheme disclosed in U.S. Pat. No. 7,041,268, the hazards associated with this extractant have thwarted practical utilization of the invention. Many other extractants for potash recovery have been disclosed in the prior art but none has been found suitable so far for practical exploitation. It is disclosed herein that the bitartrate ion, and particularly L-bitartrate, precipitates out potassium bitartrate very efficiently from SEL with ca. 90% utilization of the extractant. In contrast, recovery of potassium bi-tartrate from sea bittern directly is relatively much lower. It is further disclosed that this precipitate can be treated with magnesium hydroxide and magnesium chloride to throw out magnesium tartrate with ca. 90% recovery while yielding a nearly saturated solution of potassium chloride which can be utilized for the reaction with schoenite to obtain SOP. It is further demonstrated that the magnesium tartrate can be treated with an appropriate amount of aqueous HCl and added into a subsequent batch of SEL to throw out potassium bitartrate once again which demonstrates the recyclability of the extractant. The overall loss of tartrate over a cycle was ca. 20% but the dissolved tartrate remaining in the K-depleted SEL and KCl solutions can be precipitated out as calcium tartrate from which tartaric acid can be recovered by known methods, curtailing thereby the loss of tartaric acid per kg of KCl to <5 g. It is also demonstrated that through a similar approach, seaweed sap containing ca. 4% KCl can be concentrated to 20-22% KCl, with excellent utilization efficiency of tartaric acid, and this solution can similarly be utilized for SOP preparation. Potassium salts bearing other anions such as sulphate, nitrate, phosphate and carbonate can also be prepared from the isolated potassium bitartrate.

A multi-pond system and method is disclosed for separating sodium carbonate from sodium chloride in process purge streams from soda ash production or similar facilities. The system comprises a first pond, exposed to atmospheric environment, for receiving the process purge stream and allowing deposition of sodium carbonate in accord with phase chemistry as water is evaporated and temperatures change thereby creating a liquor with increased sodium chloride concentration. A second pond for receiving the first pond liquor, exposed to the atmospheric environment, and allowing deposition of sodium chloride in accord with phase chemistry as water evaporates and temperatures change thereby creating a second pond liquor with increased sodium carbonate concentration. Alternatively transferring at least a portion of the second pond liquor back to the first pond or into an optional third pond.