新型杂化涂层的合成及其耐碱性

采用PDMS-SiO2-TiO2体系,合成了适用于浸涂工艺的稳定涂液。以红外光谱分析了不同热处理温度下涂层的结构,研究了聚合物的含量和工艺条件对涂层耐碱性能的影响。结果表明：溶胶液可以在较长时间内保持稳定;当PDMS／（Ti＋Si）质量比为1：3、拉膜速度为60mm／min、热处理温度为250℃、溶胶溶液浓度为0．6mol／L时,涂层能抵抗60℃ 1mol／L NaOH侵蚀1天和在80℃饱和Ca（OH）2液中至少6天的加速侵蚀,显示出较好的耐碱性。     

工业生产SiC的副产品石墨废料的提纯

本文报道了"碱融-酸浸"法对工业生产SiC的副产品石墨废料的提纯研究,通过研究焙烧温度、焙烧时间、酸浸浓度、酸浸时间等因素对提纯效果的影响,确定了该类石墨提纯工艺的最佳条件:实验中NaOH与石墨质量比为2∶1,焙烧温度为650℃,焙烧时间为60min;室温下酸浸过程的HCl浓度为10%,酸浸时间为180min,此条件下提纯后的石墨其固定碳含量提升到98%以上。     

检验W9Mo3Cr4V圆钢裂纹的酸洗工艺

用电化学理论阐述了检验高速圆钢裂纹酸洗工艺的原理，分析了影响酸洗效果的因素，并对酸洗工艺参数进行了改进，优选出的酸洗工艺：用1：4盐酸溶液，酸浸温度95℃，酸浸时间15min。     

冶金法制备高纯硅过程中石油焦粉的净化研究

为给高纯硅的制备提供一种高纯原料,详细研究了石油焦粉的酸浸除杂、超声酸浸除杂、真空高温除杂,考察了石油焦粉粒度、盐酸浓度、酸浸时间、酸浸温度、酸浸液固比和搅拌对除杂效果的影响.得到的最佳工艺条件为:石焦粉颗粒控制在150μm以下,盐酸质量分数5%,反应时间6 h,水浴温度70℃,浸出液固比10∶1,搅拌速度40 r/min.在此工艺条件下,石油焦粉中金属元素杂质的去除率可高达94.69%,非金属元素杂质的去除率达39.95%.实验同时探讨了超声场作用下酸洗时间对杂质去除效果的影响,以及在真空高温焙烧条件下杂质的去除效果,最终金属元素杂质和非金属元素杂质的去除率分别达到了99.55%和99.23%.     

高灰分碳粉的碱酸法提纯

对某电解铝企业废旧阴极材料进行浮选-酸洗-磨碎处理后获得含灰分高达27.3%的碳粉,然后采用加NaOH焙烧活化-水洗-盐酸酸浸-水洗工艺对该碳粉进行除灰提纯研究。考察了氢氧化钠加入量、焙烧温度、焙烧时间、盐酸酸浸温度对碳粉灰分脱除的影响。结果表明:当设定氢氧化钠/碳粉为0.4,在1000℃焙烧1h,然后采用浓度为1mol/L的盐酸在60℃酸浸1h,可使碳粉中的灰分由27.3%降低到4.04%,碳含量由68.4%提高至94.6%,处理后的碳粉可重返阴极配料利用。     

苏州土制备纳米白炭黑的影响因素研究

以苏州土为原料制备纳米白炭黑粉体。研究并讨论了煅烧温度、酸浸条件、PH、反应时间、凝胶煅烧等因素对苏州土分解，纳米白炭黑粉体制备的影响，采用XRD，TG—DSC，SEM，TEM等方法进行了表征，结果表明苏州土在700℃左右煅烧2h后用20wt％IICl溶液在100℃酸溶2h，控制Al／HCl摩尔此为1：7时可以使二氧化硅获得率达到97％;碱溶除杂后的硅酸钠溶液加入分散剂后，在70℃～90℃时控制pH=5～7反应0．5h获得的溶胶在400℃煅烧2h获得平均粒径35nm的球形纳米白炭黑粉体。     

油页岩制油残渣制备氧化铝及其铝浸出率的研究

以抚顺东露天油页岩制油残渣为原料,用酸提法制备氧化铝,采用单因素考察法确定了抚顺东露天油页岩残渣提取氧化铝的酸溶反应最佳工艺条件为:煅烧温度850℃,煅烧时间1h,所需原料粒度0.074mm,盐酸浓度为12%,液固比为5∶1,酸溶反应温度100℃,反应时间1.5h,各项工艺指标在最佳工艺条件下,Al2O3浸出率为81.75%;采用均相化学沉淀法由酸溶反应得到的氯化铝滤液制备氧化铝的最佳工艺条件为:反应温度55℃,偏铝酸钠浓度0.4mol/L,乙酸乙酯与铝离子物质的量之比为1.7∶1,反应时间1.5h,表面活性剂的用量为总体系质量的0.3%。采用激光粒度分布仪、X射线衍射仪、X射线荧光光谱仪对所制得的产物氧化铝进行了表征和分析研究。     

黄铜表面硅烷膜制备工艺的正交试验优选及膜层的耐蚀性能

为提高黄铜制品的耐蚀性能,在黄铜表面制备硅烷膜,运用正交试验法优选了形成γ-巯丙基三甲氧基硅烷(γ-MPS)膜的工艺条件,通过对比各水解条件下成膜试样在3.5%NaCl溶液中的塔菲曲线获得了最佳浸涂工艺条件,运用阳极极化曲线、交流阻抗法和扫描电镜表征了制备的硅烷膜对黄铜基底的防护性能。结果表明:成膜最佳工艺条件为γ-MPS∶去离子水∶乙醇(体积比)=4.0∶46.5∶2.5,水解溶液p H=6.0、水解时间4.5 h、水解温度40℃、浸涂时间80 min、浸涂温度40℃、固化时间30 min、固化温度80℃;该条件下制备的黄铜表面硅烷膜在3.5%NaCl溶液中具有良好的耐蚀性能。     

聚吡咯／木单板导电复合材料的制备与表征

以FeCl3为氧化剂和掺杂剂，采用化学氧化原位吸附聚合法制备了聚吡咯／木单板复合材料。探讨了制备条件对表面电阻率和吸聚率的影响，以及获得的较优的制备条件。利用红外光谱（FT-IR）、X射线衍射（XRD）和扫描电镜（SEM）表征了材料的组成、结构和形貌。结果表明，制备条件为：单板室温吸附吡咯单体的时间30min，FeCl3浓度0．75mol／L，聚合反应时间30min，反应温度25℃。复合材料的表面电阻率可这15．53Ω／cm^2。复合材料中木单板表面吸附聚合了无定形的掺杂态的聚吡咯，聚吡咯排列紧密，有少量孔隙，无明显的方向性，且与木材表面有一定的相互作用。     

N_2/O_2分步热处理法制备高比表面积稻壳基白炭黑的研究

以稻壳为原料,在传统热解法的基础上,创新性的提出了N_2预热解、O_2煅烧的分步热处理方法制得高比表面积的白炭黑。获得了N_2/O_2分步热处理法制备稻壳基白炭黑的最佳工艺条件:盐酸浓度8%(wt,质量分数,下同)、酸浸温度120℃、料液比1∶10(稻壳g∶盐酸体积mL)、预热解温度300℃,产品的纯度可达99.2%。结果表明:最佳工艺条件下制得的白炭黑产品比表面积高达352.61m~2/g,明显高于传统热处理法。     

制备条件对ATO包覆氧化硅导电粉电性能的影响

采用非均匀成核法制备了ATO包覆氧化硅导电粉体。正交实验的结果表明,各因素对ATO包覆纤维效果的影响从大到小依次是包覆悬过程中氧化硅的用量、包覆层溶液离子浓度、反应过程的pH值、包覆时反应温度及包覆离子溶液加入速度。通过正交实验所确定ATO包覆氧化硅粉体的合理工艺参数:包覆悬过程中氧化硅的用量保持在0.4g/mL、包覆过程的pH值控制为2.0、包覆层离子浓度为0.6mol/L、包覆离子溶液加入速度为0.5mL/min、反应温度为50℃。通过正交实验所确定的合成参数所得的复合导电粉体的电阻率只有108.1Ω.cm。     

常压回流条件下拉锰矿的合成及其影响因素

MnSO₄与NaClO溶液常压回流反应制备纳米尺寸的拉锰矿, 采用X射线衍射、扫描电镜和比表面仪等表征产物的晶体结构、微观形貌和比表面积等物理化学性质, 探讨了反应温度、时间和盐酸添加量等对产物晶体结构、微观形貌和收率的影响. 结果表明, 60℃回流反应12 h产物为纳米颗粒, 并出现团聚现象, 温度升高, 颗粒粒径增大; 反应体系中添加盐酸, 颗粒粒径变小, 团聚体减少; 在100℃反应体系中添加盐酸, 首先形成粒状纳米拉锰矿, 在酸性环境中经溶解再沉淀反应转化为针状, 添加盐酸其针状形态的均一性增强, 且团聚结块趋势减弱. 低温加酸有利于形成高比表面积的拉锰矿, 可达66.32 m²/g. 产物收率随温度升高和盐酸添加量增大表现出先增加后减少的趋势, 最佳收率为97.5%.     

Synthesis of boron nitride from ferroboron Part 2 – Leaching

Abstract

Fully nitrided ferroboron powder is leached in simple mineral acids (including hydrochloric acid and sulphuric acid) in order to separate iron/iron nitrides from boron nitride. Weight loss is used to indicate the extent of leaching. Leaching begins with violent chemical reaction and this is followed by a slower, parabolic-like kinetics lasting from 24 to 48 h. In 1 M to 5 M hydrochloric acid leaching can be effectively carried out within 24 h. Amorphous boron nitride produced in mixed NH₃–N₂ at low temperature (400°C) leaches more readily than partially hexagonal boron nitride produced at higher temperatures in pure N₂. The possibility of recycling the leaching acid is also demonstrated using an electrochemical cell.     

304Cu抗菌不锈钢盐酸基酸洗工艺的研究

为了明确盐酸基酸洗液对含Cu抗菌不锈钢表面氧化层的酸洗行为,采用正交试验法研究以盐酸为基础,Fe~(3+)、H_2O_2和HNO_3为氧化剂的304Cu抗菌不锈钢酸洗工艺.并运用扫描电镜、透射电镜及电化学等手段分析经最佳配方酸洗后试样的表面形貌、成分及酸洗机理.结果表明:最佳酸洗工艺配方为HCl(36%~38%)120 ml/L、H_2O_2(30%)80 ml/L、FeCl_3·6H_2O 20g/L、HNO_310 ml/L,酸洗温度30℃,酸洗时间15 min.经该配方酸洗后材料表面平整度和光亮度较好,具有抗菌性能的点状ε-Cu相在基体上弥散分布.材料经酸洗去除氧化层后,仍具有足够含量的抗菌元素Cu存在.酸洗脱除氧化层过程由电荷传递过程控制,该酸洗液对不锈钢具有孔蚀诱导性,酸洗时间不宜过长.     

Processing of Ceramic Based Nanocomposite Using α-Al2O3 Powder and FeCl2 Solution as Starting Materials

Alumina-iron nanocomposite powders were prepared by a two-step process. In the first step, α-Al2O3-FeCl2 powder mixture was formed by mixing α-Al2O3 powders with FeCl2 solution followed by drying. In the second step, the FeCl2 in the dry power mixture was selectively reduced to iron particles. A reduction temperature of 750℃ for 15 min in dry H2 was chosen based on the thermodynamic calculations. The concentration of iron in FeCl2 solution was calculated to be 20 vol. pct in the final composite. Two techniques were used to produce composite bulk materials. The Al2O3 nanocomposite powders were divided to two batches. The first batch of the produced mixture was hot pressed at 1400℃ and 27 MPa for 30 min in a graphite die. To study the effect of oxygen on the Al2O3/Fe interface bonding and mechanical properties of the composite,the second batch was heat treated in air at 700℃ for 20 min to partially oxidize the iron particles before hot pressing. Characterization of the composites was undertaken by conventional density measurements, X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron probe micro analysis (EPMA). The suggested processing route (mixing, reduction and hot pressing)produces ceramic-metal nanocomposite much tougher than the pure Al2O3. The fracture strength of the produced Al2O3/Fe nanocomposite is nearly twice that of the pure Al2O3. The presence of spinel phase,FeAl2O4, as thick layer around the Fe particles in the Al2O3 matrix has a detrimental effect on interfacial bonding between Fe and Al2O3 and the fracture properties of the composite.     

微波辅助固相法合成锂离子电池正极复合材料Li2FeSiO4/C

以Na2SiO3.9H2O和FeCl2.4H2O为原料,采用低热固相反应获得了分散均匀的β-FeOOH/SiO2前驱体;再以Li2CO3为锂源、聚乙烯醇和超导电炭黑为复合碳源,通过微波辅助固相法合成了Li2FeSiO4/C材料.通过X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和恒电流充放电测试等方法对材料的结构、微观形貌及电化学性能进行表征.650℃下微波处理12 min可获得结晶好、晶粒细小均匀的Li2FeSiO4/C材料;在选用的微波合成体系下,超导碳和聚乙烯醇热分解的无定形碳不仅利于合成反应的顺利进行,而且提高了Li2FeSiO4的整体导电性能.制备的复合正极材料在60℃下0.05C倍率首次放电容量为129.6 mAh/g,0.5C倍率下为107.5 mAh/g,0.5C下15次循环后保持为104.8 mAh/g,具有较好的放电比容量和良好的循环稳定性能.结果表明,微波辅助固相合成工艺是制备Li2FeSiO4/C复合材料的一种很有前景的方法.     

铅锌矿尾料中氧化锌的提取和纯化

利用酸法提取铅锌矿尾料中氧化锌,研究表明,在搅拌转速一定,温度为80℃、硝酸的浓度为3mol/L、液固质量比为5∶1时,铅锌矿尾料中氧化锌的产率能达到62.7%。产品中氧化锌的相对纯度可达99.5%。碱法提取氧化锌,氢氧化钠的浓度为9mol/L时,氧化锌的产率为27.6%。对于浸出液的回收利用则是用浸出液和硝酸配比,再对铅锌矿尾料进行浸出,从而使废液循环利用。     

Hydrometallurgical recovery of zinc and lead from electric arc furnace dust using mononitrilotriacetate anion and hexahydrated ferric chloride

The purpose of this work was to study the feasibility at laboratory-scale of a new hydrometallurgical process for treating electric arc furnace dusts (EAFD). The proposed process is intended to extract zinc and lead from EAFD without destroying the iron oxides matrix. So, this material can be recycled by the steel industry. Independently of the origin of the samples, major mineralogical forms present in these wastes are Fe3O4, ZnO, ZnFe2O4 and PbOHCl. The proposed process consists of a hydrometallurgical treatment of wastes based on selective leaching of zinc and lead. Initially, a leaching is carried out utilizing a chelating agent, nitrilotriacetate anion (NTA3-), as the protonated form HNTA2-. Treatment of five EAFD samples for an hour at room temperature with a molar solution of reagent results in total leaching of the ZnO. In all cases the solubilized iron does not exceed 3 wt.%. The recovery of zinc and lead is performed by precipitation of metallic sulfides with a solution of Na2S4 sodium tetrasulfide 2M. These metallic sulfides can be used as metallurgical raw materials and the chelating reagent can be reused in the process after pH adjustment. The results of the normalized leaching test AFNOR X31-210 conducted on the leaching residues, shows that all the samples meet acceptance thresholds for hazardous wastes landfill. However, the residues contain a considerable amount of zinc as ZnFe2O4. The extraction of the zinc element requires the destruction of the ferrite structure. In this process, ZnFe2O4 is treated by FeCl3.6H2O. The reaction consists in a particle O2-/Cl- exchange allowing the recovery of zinc as ZnCl2 and iron as hematite Fe2O3. The separation of these products is accomplished by simple aqueous leaching. All of the zinc is extracted in a 8h treatment at 150 degrees C with a molar ratio FeCl3.6H2O/ZnFe2O4 equal to 10. Ultimate solid residues, which have been concentrated in iron, can be oriented towards the steel industry.     

Accelerated Corrosion of Pure Fe Induced by Gaseous ZnCl_2 at High Tempreratures

ZnCl_2 is one of the dominant aggressive species in waste incinerators or other advanced combustion power generationsystems. In this study, the influence of minor amount of gaseous ZnCl_2 on the corrosion behavior of pure iron wasexamined fat 600～800℃ in a pure oxygen environment. The corrtesion rate usually increased markedly with increasingtemperatures at a fixed ZnCl_2 content or with increased ZnCl_2 contents at a constant temperature.The corrosionproducts were composed of a thin outer layer of ZnFe_2O_4 spinel and an inner zone with a much thicker layer of