Provided is a water-insoluble crosslinked structure with an excellent metal-adsorbing effect. The crosslinked structure is formed by crosslinking a first linear polymer and a second linear polymer. The first linear polymer has a plurality of pendant groups represented by Formula (a). The second linear polymer has a plurality of pendant groups represented by Formula (a). Some of the plurality of pendant groups in the first linear polymer and some of the plurality of pendant groups in the second linear polymer are bonded to each other via a crosslinker. In the formula, ring Z represents a heterocycle containing a nitrogen atom as a heteroatom, R.sup.1 represents a single bond or an alkylene group having from 1 to 10 carbons, and Q.sup.+ represents a counter cation.

##STR00001##

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.

An apparatus for purifying sodium metal including: a top flange, a transparent slice, a hollow flange, a vacuum distillation kettle, gaskets, and bolts. With this apparatus, solid sodium is liquefied by heating. The volatile impurities contained in the liquid sodium metal evaporate out of the vacuum pump. After heating the liquid sodium to a high temperature, circulating cooling water is added to the condenser tube by radiation-auxiliary distillation. High-purity argon is then added to remove volatile impurities, and thermal radiation is performed to accelerate the evaporation rate at the surface of the liquid sodium. Consequently, gaseous sodium rapidly condenses on the condenser tube and becomes solid sodium.

An apparatus for purifying sodium metal including: a top flange, a transparent slice, a hollow flange, a vacuum distillation kettle, gaskets, and bolts. With this apparatus, solid sodium is liquefied by heating. The volatile impurities contained in the liquid sodium metal evaporate out of the vacuum pump. After heating the liquid sodium to a high temperature, circulating cooling water is added to the condenser tube by radiation-auxiliary distillation. High-purity argon is then added to remove volatile impurities, and thermal radiation is performed to accelerate the evaporation rate at the surface of the liquid sodium. Consequently, gaseous sodium rapidly condenses on the condenser tube and becomes solid sodium.

A process for recovering alkali from power boiler ash is provided. The power boiler ash is first contacted with Na.sub.2CO.sub.3 to produce a mixture containing settling and non-settling solid particles. A fraction of the settling particles is then separated from the mixture to produce a first clarified alkaline solution. The first clarified alkaline solution contains species such as NaOH and KOH depending upon the power boiler ash characteristics. The non-settling solid particles may optionally be further separated from the first clarified alkaline solution to obtain a second clarified alkaline solution. This process is also applicable for the extraction of alkali from other oxide/hydroxide containing materials.

A process for recovering alkali from power boiler ash is provided. The power boiler ash is first contacted with Na.sub.2CO.sub.3 to produce a mixture containing settling and non-settling solid particles. A fraction of the settling particles is then separated from the mixture to produce a first clarified alkaline solution. The first clarified alkaline solution contains species such as NaOH and KOH depending upon the power boiler ash characteristics. The non-settling solid particles may optionally be further separated from the first clarified alkaline solution to obtain a second clarified alkaline solution. This process is also applicable for the extraction of alkali from other oxide/hydroxide containing materials.

The disclosure relates to metal-organic cages which are a class of supramolecular structures comprising organic linkers and transition metal nodes. In an aspect an aluminum-based metal-organic cage (AI-pdc-AA) is disclosed. The cage formation was achieved via solvothermal self-assembly of an aluminum cluster and pyridine-dicarboxylic linker in the presence of acetic acid as a capping agent. The obtained supramolecular structure was characterized by single-crystal X-ray diffraction (SCXRD), thermbgravimetric analysis, and NMR spectroscopies. Based on the single crystal structure and computational analysis, the cage has a 3.7 A diameter electrophilic cavity suitable for the binding of cations, such as cesium (ionic radius 1.81 A). The host-guest interactions were probed with 1 H and 133Cs NM spectroscopies in DMSO, where at low concentrations Cs+ binds to AI-pdc-AA in a 1:1 ratio.

The present disclosure relates to the field of the preparation of high purity sodium and the safe treatment of sodium calcium slag, and discloses a method and apparatus for sodium slag recovery by using gravity separationcontrollable combustionalkaline liquor leaching process for the preparation of high purity sodium and safe treatment of sodium calcium slag. The method comprises the following steps: (1) subjecting a liquid sodium slag to a gravity stratification to obtain pure metallic sodium and high calcium content sodium slag; (2) roasting the high calcium content sodium slag to obtain a roasting slag; and (3) leaching the roasting slag by using an alkaline liquor to obtain the sodium hydroxide solution and calcium hydroxide. The method and apparatus provided by the present disclosure have advantages including high efficiency separation of sodium and calcium, saving separation time, safe and controllable production process, and continuous production process, thereby providing a safe and efficient method for the preparation of high purity sodium and safe treatment of new sodium calcium slag generated by the method, allowing continuous production of high purity sodium and safe recycle of new sodium calcium slag.

The present disclosure relates to the field of the preparation of high purity sodium and the safe treatment of sodium calcium slag, and discloses a method and apparatus for sodium slag recovery by using gravity separationcontrollable combustionalkaline liquor leaching process for the preparation of high purity sodium and safe treatment of sodium calcium slag. The method comprises the following steps: (1) subjecting a liquid sodium slag to a gravity stratification to obtain pure metallic sodium and high calcium content sodium slag; (2) roasting the high calcium content sodium slag to obtain a roasting slag; and (3) leaching the roasting slag by using an alkaline liquor to obtain the sodium hydroxide solution and calcium hydroxide. The method and apparatus provided by the present disclosure have advantages including high efficiency separation of sodium and calcium, saving separation time, safe and controllable production process, and continuous production process, thereby providing a safe and efficient method for the preparation of high purity sodium and safe treatment of new sodium calcium slag generated by the method, allowing continuous production of high purity sodium and safe recycle of new sodium calcium slag.