长治煤与生物质混合灰熔融特性研究

采用灰熔点测定仪、X射线荧光仪、X射线衍射仪和FactSage软件相结合对生物质（花生壳、稻壳）与高灰熔点长治煤混合灰的熔融特性及其熔融机制进行了研究。结果表明,两种生物质灰都可以降低长治煤的灰熔融温度,花生壳灰助熔效果优于稻壳灰,这主要与它们的化学组成和赋存形态有关。低熔点长石类矿物（钙长石、钠长石）和白榴石的生成是花生壳与长治煤混合灰熔融温度降低的主要原因;长石类矿物的生成及其与SiO₂结合生成的低温共熔物引起稻壳与长治煤混合灰熔融温度降低。热力学计算表明,在碱性氧化物Na₂O、CaO、K₂O存在时,SiO₂和Al₂O₃优先与其反应生成低熔点硅铝酸盐,一定程度上抑制了高熔点莫来石矿物的生成,从而起到助熔作用。混合灰的熔融过程可以分为含钾矿物熔融和含钙矿物熔融两个阶段,两类矿物熔融顺序：含钾矿物先于含钙矿物。     

水溶性聚合物和两亲聚合物22.丙烯酸/乙酸乙烯酯共聚物对硫酸钙沉淀形态的影响

水溶液中丙烯酸/乙酸乙烯酯无规共聚物的存在不仅降低了Na₂SO₄和CaCl₂生成CaSO₄的沉淀量和结晶速度,而且可显着减小CaSO₄粒子的大小,改变其形状和晶形,降低结晶的完善程度.     

准东煤灰渣烧结熔融过程中钠基化合物作用机理研究

将Na₂CO₃添加剂按折算为Na₂O以20%的比例掺入煤灰中制成混合灰样,对混合灰样在不同温度下烧结.对不同温度下的烧结灰进行EDS元素分析和XRD物相分析,探究钠基化合物在准东煤灰烧结过程中的转变机理.并以EDS分析结果为基础用Fact sage 5.2计算软件中的Equilib模块进行化学热力学平衡反应计算.结果表明,随着烧结温度的升高,硫会发生富集,而钠主要和硫反应生成Na₂SO₄.同时会有NaCl的产生,NaCl会与含钾化合物反应置换出KCl.NaCl、KCl和Na₂SO₄与其他物质产生低温共熔物.     

BeSO4-Al2(SO4)3-Na2SO4三元熔盐体系相图的研究

热分析法研究了BeSO₄-Al₂(SO₄)3-Na₂SO₄三元熔盐体系的状态图。体系中存在三元转熔(包晶)点P,温度490℃,组成为BeSO₄18.8Wt%,Al₂(SO₄)₃15.0%,Na₂SO₄66.2%;三元低共熔(共晶)点E₁,温度为476℃,组成为BeSO₄20.0%,Al₂(SO₄)₃11.2,%,Na₂SO₄68.8%。另一低共熔点E₂温度为595℃,组成未能确定。体系中无三元化合物生成。     

Mg2+和Na+对高熔点煤灰熔融性的影响

以山西阳泉固庄高熔点煤灰为研究对象,通过向煤灰中添加不同量的MgO与Na₂CO₃,研究了Mg²⁺与Na⁺在高温下对煤灰熔融性的影响。研究结果表明,煤灰熔融温度随氧化镁的添加(5%~25%)单调下降;而随氧化钠添加(5%~25%)出现先降后升现象,在氧化钠添加量为15% 时,灰熔点达到最低。XRD分析表明,阳泉固庄煤灰熔融温度高(大于1 750℃)的原因是高温条件下耐熔矿物莫来石、方英石的存在。添加外加剂后,高温时外加剂与硅酸盐矿物反应,生成了更多的低共熔矿物霞石、堇青石等。同时,Mg²⁺和Na⁺的加入会使得非桥氧数量增多,高温煤灰低聚物增多,降低了煤灰的熔融温度。通过三元相图以及SEM分析,高温条件下煤灰中部分元素的富集以及团聚现象是导致Mg²⁺和Na⁺对煤灰熔融温度影响不同的原因。     

高温下煤中矿物质对气化反应的影响

利用XRD对1100℃~1500℃高温下矿物质在弱还原气氛中的变化进行考察,并利用RIR对矿物质进行半定量分析,发现随着温度的升高莫来石含量增大,而SiO₂含量下降,符合SiO₂-Al₂O₃二元相图的变化。高温下部分无定形矿物质发生熔融,主要为硅铝酸盐。在煤焦二氧化碳气化过程中,熔融的硅铝酸盐与煤焦表面接触阻碍气化反应进行。利用FT-IR测定了硅铝酸盐结构的变化,说明高温下矿物质对气化反应的影响与硅铝酸盐的聚合程度存在一定的关系。     

准东煤掺烧高岭土对固钠率及灰熔融特性影响研究

选择常见的黏土矿物高岭土作为准东煤添加剂掺烧,研究了不同掺混比例、不同燃烧温度下添加剂的固钠率和煤灰熔融特性的变化,结合XRD谱图和三元相图研究了灰中矿物在高温下的演变过程。结果表明,固钠率随高岭土掺混比例增加逐渐增大,在0~2%时增长较快,2%~5%增长较慢,随燃烧温度升高略微下降;掺混后煤灰熔点随掺混比例先缓慢减小,再快速减小,后快速增加,在3%时达到1 200 ℃左右;XRD和三元相图分析结果表明,煤灰熔融特性变化是由于灰中硅钙石、钙黄长石和钙长石矿物比例的变化引起,发生低温共熔现象是导致掺混比例为3%和4%时煤灰熔点最低的主要原因;当掺混比例为2%时,固钠率在60%以上且灰熔点在1 300 ℃左右,利于固态排渣,当掺混比例为3.0%~4.0%时,灰熔点在1 200 ℃左右,利于液体排渣。     

生物质混煤燃烧过程中钾的迁移转化规律

通过将稻秆和褐煤混燃，研究了燃烧温度以及生物质掺混比例对于混燃过程中K的释放、灰样中K的赋存形式以及矿物质变化的影响。研究表明，燃烧温度对于混合燃料中K的释放影响显著。在600-750℃时，随着温度升高，水溶性K和醋酸铵溶性K大量释放到气相，使得K的释放速率较快；而当温度在750-850℃时，水溶性K和醋酸铵溶性K开始大量地转化为其他形式的K而被固定在灰样中，使得K的释放速率变得缓慢；当温度高于850℃时，随着温度升高，盐酸溶性K的分解导致K释放速率重新增大。通过XRD分析发现，灰样中水溶性K主要以KCl的形式存在，K₂SO₄的生成同时受到原料中K的含量和S/Cl比值两个因素的共同影响，原料中K的含量越高，且S/Cl比值越大，越会促进K₂SO₄的生成。同时也发现生物质和煤混燃时存在协同作用，煤中Al、Si等元素会和生物质中的K反应生成碱性硅铝酸盐，从而导致更多K留在灰烬中。     

添加助熔剂后朱集西煤灰熔融特性规律研究

以高灰熔点朱集西洗煤为对象,研究了助熔剂CaCO₃、Fe₂O₃、CaCO₃/Fe₂O₃复合助熔剂以及CaMg(CO₃)₂对其煤灰熔融特性的影响。结果表明,各助熔剂均可降低煤灰熔融温度,但助熔效果与助熔剂种类和添加量有关,采用CaCO₃/Fe₂O₃复合助熔剂以及CaMg(CO₃)₂在添加量较小时,助熔效果明显;利用FactSage热力学软件,分析了添加助熔剂对煤灰中矿物高温熔融行为的影响,为进一步掌握助熔剂的助熔机理提供理论帮助。     

长治煤与生物质混合灰熔融特性研究

采用灰熔点测定仪、X射线荧光仪、X射线衍射仪和Fact Sage软件相结合对生物质(花生壳、稻壳)与高灰熔点长治煤混合灰的熔融特性及其熔融机制进行了研究。结果表明,两种生物质灰都可以降低长治煤的灰熔融温度,花生壳灰助熔效果优于稻壳灰,这主要与它们的化学组成和赋存形态有关。低熔点长石类矿物(钙长石、钠长石)和白榴石的生成是花生壳与长治煤混合灰熔融温度降低的主要原因;长石类矿物的生成及其与SiO_2结合生成的低温共熔物引起稻壳与长治煤混合灰熔融温度降低。热力学计算表明,在碱性氧化物Na_2O、CaO、K_2O存在时,SiO_2和Al_2O_3优先与其反应生成低熔点硅铝酸盐,一定程度上抑制了高熔点莫来石矿物的生成,从而起到助熔作用。混合灰的熔融过程可以分为含钾矿物熔融和含钙矿物熔融两个阶段,两类矿物熔融顺序:含钾矿物先于含钙矿物。     

Influence of common ions during ultrafiltration of mixtures: Part I. Common anions mixtures

A lot of experiments were investigated to show the behaviour of an ultrafiltration membrane during the filtration of pure salt solutions. What happens when the filtered solution contains several ions?

In this paper, results are given concerning the filtration of mixtures of two salts solutions, salts with a common anion: NaCl + CaCl₂ and Na₂SO₄ + CaSO₄.

The surface charge of the membrane is characterized by streaming potential measurements and rejection rates by means of chromatography. These results confirm the adsorption of divalent ions on the surface and a good selectivity for divalent cations.     

The effect of CTAB on Na2SO4 nucleation in mixed Na2SO4/CTAB aerosols by FTIR-ATR technology

FTIR-ATR technology is used to study the efflorescence kinetic of Na_2SO_4 and mixed Na_2SO_4/CTAB aerosols.As the RH decreased linearly,the v_3-SO_4~2 band shifts from 1094 cm~1 to 1132 cm~1,suggesting the phase transition of Na_2SO_4 from solution to crystal phase(Ⅲ).For pure Na_2SO_4 aerosols,the ERH is 75.1%RH,whereas the efflorescence point of mixed Na_2SO_4/CTAB aerosols(74.2%) is lower.By further analysis of IR differential spectra,the ratio of Na_2SO_4 crystals in mixed aerosols is only 62.7%and the heterogeneous nucleation rate of Na_2SO_4 in Na_2SO_4/CTAB mixed aerosols is lower than that in pure Na_2SO_4 aerosols.They showed that CTAB assembled into reversed micelle and part Na_2SO_4 droplets are in the core to form core-shell structure,and CTAB shell prevents core Na_2SO_4 solutions from crystallizing.However,the counter ion Br for CTAB reversed micelle can interact with Na~+ ions,which decreases the crystallization rate of free Na_2SO_4 droplets and ERH is delayed.     

Li2SO4-MgSO4及LiNO3-Mg(NO3)2熔盐体系的研究

用目测变温法和差热分析法研究了Li₂SO₄-MgSO₄、LiNO₃-Mg(NO₃)₂熔盐体系。在前一体系中有固液异组成化合物Li₂SO₄·2MgSO₄生成,它在832°熔化分解。化合物与Li₂SO₄间形成低共熔点,温度为647℃,组成含MgSO₄23.6Wt%。Li₂SO₄多晶转变点575℃,在加入MgSO₄后形成类低共熔点,温度552℃,组成含MgSO₄4.2%。LiNO₃-Mg(NO₃)₂为一简单低共熔体系,共晶点含Mg(NO₃)₂47.3%,温度200℃。     

Mechanism of Lithium and Cobalt Recovery from Spent Lithium-ion Batteries by Sulfation Roasting Process

Different from the traditional pyrometallurgical recovery process of Li and Co from spent lithium-ion batteries, a new recovery method for Li and Co was established by converting LiCoO₂ into water-soluble metal sulfates by roasting a mixture of LiCoO₂ and NaHSO₄·H₂O. The evolution law of the mixture with increased roasting temperature was investigated by thermogravimetry-differential scanning calorimetry(TG-DSC), in situ X-ray diffraction(XRD), XRD, and X-ray photoelectron spectroscopy(XPS). The results show that the phase transition of LiCoO₂ mixed with NaHSO₄·H₂O with increased temperature proceeded as follows:LiCoO₂, NaHSO₄·H₂O→LiCoO₂, NaHSO₄→Li_1-xCoO₂, LiNaSO₄, Na₂S₂O₇, Na₂SO₄→Li_1-xCoO₂, Co₃O₄, LiNaSO₄, Na₂SO₄→Co₃O₄, LiNaSO₄. The reaction mechanism of this roasting process may be as follows:LiCoO₂+NaHSO₄·H₂O→1/2Li₂SO₄+ 1/2Na₂SO₄+1/3Co₃O₄+1/12O₂+3/2H₂O, Li₂SO₄+Na₂SO₄=2LiNaSO₄.     

苦参碱和槐定碱在多刺激响应性水凝胶薄膜电极上的可调控电化学行为及其逻辑门构建

采用苦参碱(Matrine, MT)和槐定碱(Sophoridine, SR)作为电活性药物分子探针, 考察了聚(N-异丙基)丙烯酰胺(PNIPAM)水凝胶薄膜的刺激响应特性; 并通过循环伏安(CV)法和扫描电子显微镜(SEM)研究了PNIPAM在不同外界刺激条件(如温度、 盐浓度和甲醇)下结构的改变. 在25 ℃时, 药物分子MT和SR在玻碳电极上产生较大的氧化峰电流, 随着温度升高至40 ℃, 药物分子探针的氧化峰电流逐渐减小. 考察了不同Na₂SO₄浓度和不同比例甲醇对PNIPAM水凝胶薄膜的影响, 发现MT和SR的氧化峰电流随着Na₂SO₄浓度(00.45 mol/L)和甲醇比例(040%)的升高而减小. 结果表明, MT和SR可作为分子探针研究PNIPAM水凝胶薄膜对环境的三重刺激响应性开关行为, 并可进一步构筑3-输入/2-输出的逻辑门系统.     

燃烧与催化气化灰中铝溶出行为的研究

实验对比了燃烧灰与负载Na_2CO_3催化气化灰中Al的溶出行为,考察了Na_2CO_3负载量(0-15%,质量分数)和温度(600-1 000℃)对催化气化灰中主要矿物组成与Al溶出行为的影响。同时,采用XRD分析了燃烧灰、催化气化灰以及酸浸残渣的主要组成。结果表明,燃烧灰的主要组成为莫来石,而催化气化灰的主要组成为硅铝酸钠((Na_2O)_(0.33)NaAlSiO_4)。6 mol/L硫酸、60℃和30 min浸取条件下,燃烧灰的浸出率只有40%,而Na_2CO_3负载量为10%的催化气化灰的浸出率达到88%。催化气化灰更易于回收灰中的Al。     

Solid-liquid Phase Equilibria in the Process of Producing Lithium Hydroxide from Lithium Sulfate

The solid-liquid phase equilibria in the process of producing lithium hydroxide from lithium sulfate at 283.15, 298.15 and 323.15 K were studied via the isothermal solubility equilibrium method, and the solid species, phase diagrams, solution densities and pH were determined. The results show that four solid species of Na₂SO₄·10H₂O, Na₂SO₄·2.5H₂O, Na₂SO₄ and LiOH·H₂O occurred in the system, among them, Na₂SO₄·2.5H₂O was a new solid species not reported in the open literature, which was determined via chemical analysis, Karl Fischer water titration, X-ray diffraction(XRD), thermogravimetic analysis(TG) and differential scanning calorimetry(DSC) testing. Based on the SLE data, one systemic process to produce LiOH·H₂O from Li₂SO₄·H₂O was proposed including two crystallization steps at lower and higher temperatures.     

Modelling of calcium sulphate solubility in concentrated multi-component sulphate solutions

The chemistry of several calcium sulphate systems was successfully modelled in multi-component acid-containing sulphate solutions using the mixed solvent electrolyte (MSE) model for calculating the mean activity coefficients of the electrolyte species. The modelling involved the fitting of binary mean activity, heat capacity and solubility data, as well as ternary solubility data. The developed model was shown to accurately predict the solubility of calcium sulphate from 25 to 95 °C in simulated zinc sulphate processing solutions containing MgSO₄, MnSO₄, Fe₂(SO₄)₃, Na₂SO₄, (NH₄)₂SO₄ and H₂SO₄. The addition of H₂SO₄ results in a significant increase in the calcium sulphate solubility compared to that in water. By increasing the acid concentration, gypsum, which is a metastable phase above 40 °C, dehydrates to anhydrite, and the conversion results in a decrease in the solubility of calcium sulphate. In ZnSO₄–H₂SO₄ solutions, it was found that increasing MgSO₄, Na₂SO₄, Fe₂(SO₄)₃ and (NH₄)₂SO₄ concentrations do not have a pronounced effect on the solubility of calcium sulphate. From a practical perspective, the model is valuable tool for assessing calcium sulphate solubilities over abroad temperature range and for dilute to concentrated multi-component solutions.     

CaO加入条件下煤与CaSO_4氧载体化学链燃烧的反应性能研究

以小型流化床为反应器、水蒸气为气化介质,在CaSO4氧载体中加入CaO颗粒进行煤气化—氧载体还原反应实验。实验结果表明,添加CaO改善了煤气化—CaSO4还原反应性能,提高了煤气化—CaSO4还原反应速率和CO2生成速率。但CaO添加剂的催化作用随反应温度的提高而减弱。900℃是较适宜的反应温度,此温度下加入适量CaO(CaO/CaSO4物质的量比1.18),气态硫化物释放得到显著抑制,SO2和H2S降幅分别为63.19%和27.37%;同时,还能控制CO2被吸收固化成CaCO3的比例低于2%。