Numerical Modelling of Dissolving and Driving Exploitation of Potash Salt in the Qarhan Playa——A Coupled Model of Reactive Solute Transport and Chemical Equilibrium in a Multi-component Underground Brine System

Firstly, the macroscopic chemical equilibrium state of a series of chemical reactions between intercrystal brine and its media salt layer （salt deposit） in Qarhan Salt Lake was studied by using the Pitzer theory. The concept of macroscopic solubility product and its relation with accumulated ore dissolving ratio were presented, which are used in the numerical model of dissolving and driving exploitation of potassium salt in Qarhan Salt Lake. And secondly, with a model forming idea of transport model for reacting solutes in the multi-component fresh groundwater system in porous media being a reference, a two-dimensional transport model coupled with a series of chemical reactions in a multi-component brine porous system （salt deposits） was developed by using the Pitzer theory. Meanwhile, the model was applied to model potassium/magnesium transport in Qarhan Salt Lake in order to study the transfer law of solid and liquid phases in the dissolving and driving process and to design the optimal injection/abstraction strategy for dissolving and capturing maximum Potassium/ Magnesium in the mining of salt deposits in Qarhan Salt Lake.

Research on shell-side heat and mass transfer with multi-component in LNG spiral-wound heat exchanger under sloshing conditions

The spiral-wound heat exchanger(SWHE) is the primary low-temperature heat exchanger for large-scale LNG plants due to its high-pressure resistance, compact structure, and high heat exchange efficiency. This paper studied the shell-side heat and mass transfer characteristics of vapor-liquid two-phase mixed refrigerants in an SWHE by combining a multi-component model in FLUENT software with a customized multicomponent mass transfer model. Besides, the mathematical model under the sloshing condition was obtained through mathematical derivation, and the corresponding UDF code was loaded into FLUENT as the momentum source term. The results under the sloshing conditions were compared with the relevant parameters under the steady-state condition. The shell-side heat and mass transfer characteristics of the SWHE were investigated by adjusting the component ratio and other working conditions. It was found that the sloshing conditions enhance the heat transfer performance and sometimes have insignificant effects. The sloshing condition is beneficial to reduce the flow resistance. The comprehensive performance of multi-component refrigerants has been improved and the improvement is more significant under sloshing conditions, considering both the heat transfer and pressure drop.These results will provide theoretical support for the research and design of multi-component heat and mass transfer enhancement of LNG SWHE under ocean sloshing conditions.

Biomineralization of soil with crude soybean urease using different calcium salts

Calcium salt is an important contributing factor for calcium-based biomineralization.To study the effect of calcium salt on soil biomineralization using crude soybean urease,the calcium salts,including the calcium chloride (CaCl_(2)),calcium acetate ((CH_(3)COO)_(2)Ca) and calcium nitrate (Ca(NO_(3))_(2)),were used to prepare the biotreatment solution to carry out the biomineralization tests in this paper.Two series of biomineralization tests in solution and sand column,respectively,were conducted.Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were performed to determine the microscopic characteristics of the precipitated calcium carbonate (CaCO_(3)) crystals.The experimental results indicate that the biomineralization effect is the best for the CaCl2 case,followed by (CH_(3)COO)_(2)Ca,and worst for Ca(NO_(3))_(2) under the test conditions of this study (i.e.1 mol/L of calcium salt-urea).The mechanism for the effect of the calcium salt on the biomineralization of crude soybean urease mainly involves: (1) inhibition of urease activity,and (2) influence on the crystal size and morphology of CaCO_(3).Besides Ca^(2+) ,the anions in solution can inhibit the activity of crude soybean urease,and NO_(3)− has a stronger inhibitory effect on the urease activity compared with both CH_(3)COO^(−) and Cl^(−) .The co-inhibition of Ca^(2+) and NO_(3)− on the activity of urease is the key reason for the worst biomineralization of the Ca(NO_(3))_(2) case in this study.The difference in biomineralization between the CaCl_(2) and (CH_(3)COO)_(2) Ca cases is strongly correlated with the crystal morphology of the precipitated CaCO_(3).

Pervaporation performance and characterization of hydrophilic ZSM-5 zeolite membranes for high inorganic acid and inorganic salts

The hydrophilic ZSM-5 zeolite membranes are applied to separate the inorganic acid solutions and inorganic acid/inorganic salt mixtures by pervaporation,and the membrane presents good stability,dehydration,and desalination performance.Influences of inorganic acid type(H_(2)SO_(4),H_(3)PO_(4),HNO_(3),and HCl),H_(2)SO_(4)concentration(1-6 mol·L^(-1)),test temperature(60-90℃)and inorganic acid/inorganic salt type(2 mol·L^(-1)H_(2)SO_(4)and sulfate,2 mol·L^(-1)H3PO4 and phosphate)on the pervaporation performance are investigated in this work.Either for concentrating 3%(mass)H_(2)SO_(4)solution or consecutive dehydrating 20%(mass)H_(2)SO_(4)solution,the hydrophilic ZSM-5 zeolite membrane has a good dehydration performance and stability.Even though the H_(2)SO_(4)concentration and test temperature are increased to 6 M and 90℃,only H_(2)O molecules could pass through the membrane and pH value of the permeation is kept neutral.Besides,the membrane has good dehydration and desalination performance for H_(2)SO_(4)/sulfates and H_(3)PO_(4)/phosphate mixtures,and the rejection of natrium salt,molysite,and magnesium is almost 100%.

A non-nucleophilic electrolyte based on all-inorganic salts with conditioning-free characteristic for rechargeable magnesium batteries

Conditioning-free electrolytes with high reversibility of Mg plating/stripping are of vital importance for the commercialization of the superior rechargeable magnesium batteries(RMBs).In the present work,a non-nucleophilic electrolyte(denoted as MLCH)based on all-inorganic salts of MgCl_(2),LiCl and CrCl_(3) for RMBs is prepared by a straightforward one-step reaction.As a result,the MLCH electrolyte shows the noticeable performance of high ionic conductivity(3.40 mS cm^(−1)),low overpotential(∼46 mV vs Mg/Mg^(2+)),high Coulombic efficiency(∼93%),high anodic stability(SS,∼2.56 V vs Mg/Mg^(2+))and long-term(more than 500 h)cycling stability,especially the conditioning-free characteristic.The main equilibrium species in the MLCH electrolyte are confirmed to be the tetracoordinated anions of[LiCl2(THF)2]−and solvated dimers of[Mg_(2)(μ-Cl)3(THF)6]+.The addition of LiCl can assist the dissolution of MgCl_(2) and activation of the electrode/electrolyte interface,resulting in a superior Mg plating/stripping efficiency.The synergistic effect of LiCl,CrCl_(3),a small amount of HpMS and the absence of polymerization THF enable the conditioning-free characteristic of the MLCH electrolyte.Moreover,the MLCH electrolyte exhibits decent compatibility with the cathodic materials of CuS.The Mg/CuS full cell using the MLCH electrolyte presents a discharge specific capacity of 215 mAh g^(−1)at 0.1 C and the capacity can retain∼72%after 40 cycles.Notably,the MLCH electrolyte has other superiorities such as the broad sources of materials,low-cost and easy-preparation,leading to the potential prospect of commercial application.

AVAILABILITY SIMULATION OF MULTI-COMPONENT SYSTEM BASED ON OPPORTUNISTIC MAINTENANCE POLICY

A multi-component system has the long fixed maintenance time, so the opportunistic maintenance policy is adopted to put preventive replacement and corrective replacement together, so that the long fixed maintenance time can be shared by more than one component, and the system availability can be improved. Then, the generation characteristics of the random failure time are researched based on the replacement maintenance and the minima[ maintenance. Furthermore, by choosing the opportunistic replacement ages of each component as opti- mized variables, a simulation algorithm based on an opportunistic maintenance policy is designed to maximize the total availability. Finally, the simulation result shows the validity of the algorithm by an example.

Column leaching process of rare earth and aluminum from weathered crust elution-deposited rare earth ore with ammonium salts

In order to better understand the leaching process of rare earth （RE） and aluminum （Al） from the weathered crust elutiondepositedRE ore, the mass transfer of RE and Al in column leaching was investigated using the chromatographic plate theory. Theresults show that a higher initial ammonium concentration in a certain range can enhance the mass transfer process. pH of leachingagent in the range of 2 to 8 almost has no effect on the mass transfer efficiency of RE, but plays a positive role in the mass transferefficiency of Al under strong acidic condition （pH〈4）. There is an optimum flow rate that makes the highest mass transfer efficiency.The optimum leaching condition of RE is the leaching agent pH of 4？8, ammonium concentration of 0.4 mol/L and flow rate of0.5 mL/min. The mass transfer efficiencies of RE and Al both follow the order： （NH4）2SO4〈NH4Cl〈NH4NO3, implying thecomplexing ability of anion.

Purification of metallurgical grade silicon by electrorefining in molten salts

Electrochemical studies on silicon deposition were performed in molten salt electrolytes. Purification of metallurgical grade silicon by electrorefining was carried out in molten Si-chloride salts at temperatures from 973 K to 1223 K. It was found that the use of a liquid alloy anode of silicon and copper was beneficial in molten CaCl2 with NaCl, CaO and dissolved Si. ICP-AES analysis results showed efficient removal of metal impurities, such as titanium, aluminum and iron, which are present in significant quantities in the feedstock. The contents of boron and phosphorus in the silicon after electrorefining were reduced from 36×10-6 and 25×10-6 to 4.6×10-6 and 2.8 ×10-6, respectively. The energy consumption of electrorefining was estimated to be about 9.3 kW?h/kg.

Electrochemical behaviors of Mg^(2+) and B^(3+) deposition in fluoride molten salts

By using cyclic and linear sweep voltammetry,the electrochemical deposition behaviors of Mg^2＋ and B^3＋ in fluorides molten salts of KF-MgF2 and KF-KBF4 at 880℃ were investigated,respectively.The results show that the electrochemical reduction of Mg^2＋ is a one-step reaction as Mg^2＋＋2e-→Mg in KF-1%MgF2 molten salt,and the electrochemical reduction of B^3＋ is also a one-step reaction as B^3＋＋3e-→B in KF-KBF4 （1%,2% KBF4） molten salts.Both the cathodic reduction reactions of Mg^2＋ and B^3＋ are controlled by diffusion process.The diffusion coefficients of Mg^2＋ in KF-MgF2 molten salts and B^3＋ in KF-KBF4 molten salts are 6.8×10^-7 cm^2/s and 7.85×10^-7 cm^2/s,respectively.Moreover,the electrochemical synthesis of MgB2 by co-deposition of Mg and B was carried out in the KF-MgF2-KBF4 （molar ratio of 6：1：2） molten salt at 750℃.The X-ray diffraction analysis indicates that MgB2 can be deposited on graphite cathode in the KF-MgF2-KBF4 molten salt at 750℃.

Mixed salts for lithium iron phosphate-based batteries operated at wide temperature range

To achieve good performance for LiFePO4-based batteries operated at a wide temperature range,mixed salts of LiBF4 LiBOB（lithium bis（oxalato）borate） and LiTFSI（lithium bis（trifluoromethanesulfonyl）imide）-LiBOB were investigated as alternative lithium salts to LiPF6 in non-aqueous electrolytes.LiFePO4/Li half cells using LiPF6,LiBF4-LiBOB and LiTFSI-LiBOB slats as lithium salts were investigated by galvanostatic cycling,cyclic voltammetry,thermogravimetric analysis.The results show that LiBF4-LiBOB and LiTFSI-LiBOB mixed salts are much more thermally stable than LiPF6.Corrosion of Al foil in the LiTFSI-based electrolytes can be suppressed successfully by the addition of LiBOB as a co-salt.The electrochemical performance of LiBF4-LiBOB and LiTFSI-LiBOB mixed salts based cells are both better than that of LiPF6-based cell.LiTFSI-LiBOB mixed salt based electrolyte is considered to be a very promising electrolyte candidate for Li-ion batteries that will be used in wide-temperature applications.

Electrical conductivity of NaF-AlF_3-CaF_2-Al_2O_3-ZrO_2 molten salts

The electrical conductivity of NaF-AlF3-CaF2-Al2O3-ZrO2 system was studied by a tube-type cell with fixed cell constant. The results show that the electrical conductivity of NaF-AlF3-3%Al2O3-3%CaF2-ZrO2 molten salt system decreases with increase of ZrO2 content in an interval of 0-5%. The increase of 1%ZrO2 results in a corresponding electrical conductivity decrease of 0.02 S/cm, and the equivalent conductivity increases with the increase of molar ratio of NaF to AlF3. When the temperature increases by 1 °C, the electrical conductivity increases by 0.004 S/cm. At last, the regression equations of electrical conductivity relative to temperature and ZrO2 are obtained by quadratic regression analysis.

用Bunte Salts法合成苯甲醛二正丁硫醇缩醛的研究

以苯甲醛、硫代硫酸钠和溴代正丁烷为原料 ,用 Bunte Salts法合成苯甲醛二正丁硫醇缩醛。较好的反应条件是 :Bunte Salts与苯甲醛的摩尔比为 3.3∶ 1 ,催化剂浓盐酸的用量为 7.5m L,回流反应 9h。在该条件下产率达 79.5% ,并用 IR、1

Synthesis and analgesic activities studies on bispiperazinium (BPZ) salts

Selecting compound 97-9-G4 as lead compound, a series of bispiperazinittm salts 5a-h were designed, synthesized and evaluated for their analgesic activities. The results show that phenylethyl group of 97-9-G4 is a crucial pharmacophore; the intro- duction of electron-withdrawing group on benzene ring is favorable to the activity.

用Bunte Salts法合成正丁醛二正丁硫醇缩醛的研究

以正丁醛、硫代硫酸钠和溴代正丁烷为原料，用BunteSalts法合成正丁醛二正丁硫醇缩醛。较好的反应条件是：按本文实验量加入催化剂浓盐酸1．5mL，回流反应时间为9h。在该条件下反应产率达82．6％，用IR、1HNMR证实了其结构。

Interaction of Soybean Phospholipids Based Lipo-Vesicle and Surfactants of Bile Salts In Vitro

Liposomes were prepared with natural soybean phospholipids by extrusion method after rotating-film evaporating technique. Transmission electron micrography was used to detect the appearances of the prepared liposomes, and the liposome diameter was also measured. The prepared liposomes were sphere in shape with the mean diameter of 217 nm and span of 0.838. The phospholipid bilayer structure, suitable for entrapping various effector molecules, could be seen clearly under transmission electron microscopy. The bile salts of sodium cholate and sodium deoxycholate were used as the surfactants to investigate their interaction with liposomes. The turbidities for the mixture of bile salts and liposomes were evaluated by the visible spectrometry method at the wavelength of 500 nm. And the diameter changes of liposomes were also tested to examine the effect of bile salts on liposomes. At the beginning, the diameters and turbidities of liposomes increased a little as the result of mixed micelles formation during the different stages for the structure changes of surfactant-liposomes micelles. The further added bile salts decreased the diameters and turbidities of liposomes. The liposome suspension underwent several rearrangements before small mixed micelles formed. And the diameter of liposomes changed regularly. The interaction of bile salts and liposomes is important for the further study of the behaviors of liposomes in vivo. The drug loaded and release properties of liposomes can also be well reflected by the interaction of liposomes and surfactants.

Effect of salts on earthen materials deterioration after humidity cycling

Salt weathering leads to destruction of many valuable cultural heritage monuments and porous building material. The present study aims at providing more laboratory evidence for evaluating the effects of salt precipitation on the deterioration process. In view of this, the remoulded soil specimens were mixed with three kinds of salts(i.e., NaCl, Na_2SO_4 and their mixture) with different salt concentrations, and the specimens were kept in environment cabinet for undergoing different wet-dry cycles. After each cycle, the ultrasound velocity measurements were employed to monitor the deterioration process. For the specimens that have suffered three wet-dry cycles, the mechanical properties(i.e. shear strength and compression strength) were determined to evaluate the degree of deterioration. Furthermore, considering the realistic conservation environment of earthen sites, mechanical stability of these specimens against sediment-carrying wind erosion was conducted in a wind tunnel. These experiments results indicate that the overall average velocities of the specimens after the third cycle are significantly lower than those subjected to only one cycle. Ultrasound velocity, mechanical strength and wind erosion rate decrease when salt content increases. However, the internal friction angle increases firstly, and then decreases with the increase in salt content added to the specimens. Na_2SO_4 contributes most of the surface deterioration, while NaCl plays little role in the deterioration. The damage potential of the salt mixture is less obvious and largely dependent on the crystallisation location.

CeO_2 as the Oxygen Carrier for Partial Oxidation of Methane to Synthesis Gas in Molten Salts: Thermodynamic Analysis and Experimental Investigation

A new technique -- the direct partial oxidation of methane to synthesis gas using lattice oxygen in molten salts medium has been introduced. Using CeO2 as the oxygen carrier, thermodynamic data were calculated in the reaction process, and the results indicated that direct partial oxidation of methane to synthesis gas using lattice oxygen of cerium oxide is feasible in theory. In a stainless steel reactor, the effects of temperature and varying amounts of γ-Al2O3 supported CeO2 on cn4 conversion, H2 and CO selectivity, were investigated, respectively. The results show that 10% CeO2/γ-Al2O3 has the maximal reaction activity at a temperature of 865 ℃ and above, the H2/CO ratio in the gas that has been produced reaches 2 and the CH4 conversion, H2 and CO selectivity reached the following percentages： i.e. 61%, 89%, and 91% at 870 ℃, respectively. In addition, increase of reaction temperature is favorable for the partial oxidation of methane.

Capture and electro-splitting of CO_2 in molten salts

Due to the serious greenhouse gas effects caused by the increasing concentration of atmospheric CO_2,carbon capture and storage(CCS) has been an important area of research and many technologies are developed within this field. Molten salt CO_2 capture and electrochemical transformation(MSCC-ET) process is a desirable method due to a high CO_2 solubility, a wide potential window of molten salts and easily-controlled electrode reactions. Generally, electro-splitting CO_2 in molten salts begins with CO_2 absorption reactions to form CO_3^(2-), which is then followed by the carbon deposition at the cathode and O_2 evolution at the anode. As a result, CO_2 is electro-converted to O_2 and carbon with different morphologies, compositions, microstructures and functional properties. This report introduces the MSCC-ET process, summarizes the reactions occurring in the molten salts and at the electrode surfaces, as well as the morphological variations of the cathodic products. The inert anode materials, cost estimation and scale-up evaluation of the process are then discussed. It is presumed that with a comprehensive understanding of the electrode reactions during electrolysis and the functional properties of carbon materials obtained during CO_2 electro-splitting can provide a foundation for further developing this environmentally friendly process.

Application of annexation principle to the study of thermodynamic properties of ternary molten salts CaCl_2-MgC_2-NaCl

Based on the practical basis of measured activities and phase diagrams aswell as in the light of the mass action law. the model of inseparable cations and anions of moltensalts and mattes, and the annexation principle of two kinds of solutions in binary melts, thecalculating model of mass action concentrations of molten salts CaCl_2-MgCl_2-NaCl was formulated.The results of calculation not only agree with experimental values, but also obey the mass actionlaw, testifying that the model formulated can embody the structural characteristics of these ternarysalts, and that the model of inseparable cations and anions as well as the annexation principle oftwo kinds of solutions in binary melts are also applicable to these ternary salts.

Multi-component Dirac equation hierarchy and its multi-component integrable couplings system

A general scheme for generating a multi-component integrable equation hierarchy is proposed. A simple 3M- dimensional loop algebra ~X is produced. By taking advantage of ~X a new isospectral problem is established and then by making use of the Tu scheme the multi-component Dirac equation hierarchy is obtained. Finally, an expanding loop algebra ~FM of the loop algebra ~X is presented. Based on the ~FM, the multi-component integrable coupling system of the multi-component Dirac equation hierarchy is investigated. The method in this paper can be applied to other nonlinear evolution equation hierarchies.