高能球磨机搅拌桨尺寸对SiO_2颗粒细化的影响

采用卧式高能球磨机制备纳-微SiO_2粉末,首先利用离散单元法模拟了球磨设备搅拌桨尺寸改变时,研磨仓体内钢球与物料的相互碰撞情况,以及搅拌桨尺寸对SiO_2颗粒细化的影响,然后根据模拟结果开展了相应的实际试验。结果表明,试验验证结果与模拟仿真结果一致,球磨机搅拌桨叶片尺寸对SiO_2的颗粒细化具有重要影响;在球磨机转速为1 000～1 100 r/min、钢球直径3 mm、球料比15∶1的条件下,叶片规格尺寸为长度115 mm、宽度8 mm时,使用卧式高能搅拌磨机球磨90 min即可得到最终粒径在300～500 nm的纳-微SiO_2粉末。     

ZnFe2O4的制备及其酸溶特性研究*

本文对分析纯的ZnO和Fe₂O₃超声波分散25min后烘干,高能球磨预处理5h,采用恒温焙烧法制备非纳米ZnFe₂O₄,对铁酸锌产品进行粒度分析、XRD分析及SEM分析,研究焙烧温度对产品的粒度特征、结晶状况、微观形貌的影响。所制铁酸锌产品经机械活化后进行微波焙烧处理,并对其进行孔径和比表面积分析。利用插值法和响应曲面法对微波处理后产品的硫酸浸出实验数据进行分析,研究始酸浓度、浸出温度对铁酸锌酸溶特性的单因素影响及交互作用影响。     

不同含量SiO2 对球团质量的影响

通过邯钢现有生产所用的四种矿粉,配矿得到不同SiO₂含量的球团矿,运用一系列的实验方案和检测手段找出邯钢球团矿最优的抗压强度和冶金性能下的SiO₂含量,并探究了不同SiO₂含量对邯钢球团矿的抗压强度和冶金性能的规律。试验结果表明：SiO₂含量在3%时所生产的球团矿抗压强度最强,随着SiO₂含量的增加球团矿的抗压强度下降,但试验所得到的球团矿均在2000N以上;SiO₂含量在3%时,还原度最高,达到了83%,随着SiO₂含量的增加球团矿的还原度下降;SiO₂含量在3%时,低温还原分化率最大,随着SiO₂含量的增加球团矿的低温还原分化率趋于下降,但下降幅度不是太大;SiO₂含量在3%时,软化温度最高,熔滴温度区间最窄,熔滴性最好,随着SiO₂含量的增加球团矿的软化温度下降,熔滴温度区间变宽,熔滴性能变差。     

韦世强1,2蒋超超2张亮玖2谭海翔1,2周慧荣2李宽2

采用真空熔炼法制备出La_1.6Y_0.4Mg₁₆Ni稀土合金,通过采用反应球磨法球磨合金10 h,采用SEM、粒度分析跟XRD测试来分析球磨前后合金颗粒的形貌跟粒径,对比球磨10h前后合金粉电化学性能及动力学性能的差异。结果表明,球磨10h后合金粉末粒径集中分布在45微米附近,且粒径分布集中,颗粒大致呈球形,形成了非晶相。球磨合金制备的材料放电循环稳定性高,高倍放电性能好,电化学性能得到改善。     

热喷涂用NiCrCoAlY-MoSi2纳米复合粉体制备与表征

以MoSi2粉和NiCrCoAlY粉为原料,氩气做保护气,采用高能球磨技术成功制备了NiCrCoAlY-MoSi2纳米金属陶瓷复合粉体。利用X射线衍射仪(XRD)、激光粒度分析仪、扫描电子显微镜(SEM)、振实密度仪和松装密度仪等对粉体的微观组织、晶粒尺寸和性能进行了表征和分析。结果表明:NiCrCoAlY-MoSi2粉体高能球磨30 h,纳米级强化相MoSi2均匀弥散分布在粘结相NiCrCoAlY上,平均晶粒尺寸为25 nm。该粉体由大量椭圆形颗粒和少量细小团聚颗粒组成,流动性能明显改善,可稍加过筛后直接用于热喷涂。     

基于镁合金微弧氧化技术制备浅绿色陶瓷膜

在硅酸盐体系下,研究AZ91D镁合金微弧氧化着色盐种类及用量对陶瓷膜颜色、微观结构及组成的影响。制备的彩色陶瓷膜通过X-衍射、TEM和SEM分析表明陶瓷膜由Mg₂SiO₄、MgCr₂O₄和MgO尖晶石相组成;表面由许多颗粒组成,颗粒上有孔洞;膜由里向外由致密层、过渡层和疏松层组成。研究表明陶瓷膜颜色与主盐的浓度无关,K₂Cr₂O₇、KMnO₄为着色盐均可着色,以K₂Cr₂O₇为着色盐制备的陶瓷膜为浅绿色。     

三维Co2Mn3Ox纳米薄膜的制备及电化学储能特性

泡沫镍的良好导电性及多孔的三维骨架结构有助于电子传输和电解液接触。以泡沫镍为模板,采用水热合成法制备三维Co₂Mn₃O_x纳米薄膜,并对其作为超级电容器电极材料的电化学储能特性进行了实验研究。结果表明：在泡沫镍表面可控合成了超薄的三维Co₂Mn₃O_x纳米薄膜,该薄膜由超小的纳米颗粒组成,并具有一定的多孔结构;合成的三维Co₂Mn₃O_x纳米薄膜作为超级电容器电极材料表现出了优异的储能特性,如在电流密度为5 A?g^-1下具有1092.5 F?g^-1的比电容,恒流充放电循环1000次后电容保留率高达89.1%。此外,以Co₂Mn₃O_x纳米薄膜为正极材料,活性碳为负极材料,组装的非对称超级电容器表现出高的能量密度、高的功率密度以及良好的循环稳定性。该研究丰富了自支撑、无粘结剂、高储能特性的赝电容超级电容器电极材料种类,为电化学储能薄膜材料的设计提供了思路。     

天然膨润土对Cr(VI)的吸附动力学及等温线研究

研究所用膨润土的主要成分为SiO₂和Al₂O₃,属于钙基膨润土,BET表面积为47.98 m₂/g。在恒温及恒定pH条件下,用动态吸附法研究了膨润土对Cr(VI)的吸附特性,结果表明其较好符合Lagergren二级吸附速率方程。利用Langmuir等温线方程和Freundlich等温线方程对动态吸附过程进行拟合,发现其吸附等温反应与Langmuir等温线更适合,属于表面单分子吸附。     

柔性Ni网基底上电沉积制备ZnO纳米结构及其光电性能的研究

通过电化学沉积技术,以ZnCl₂与O₂为原料,在柔性金属Ni网基底上制备得到ZnO纳米棒阵列,后采用Zn (CH₃COO)₂胶体铺膜处理,再次电沉积得到ZnO分级有序纳米结构。并利用SEM、XRD、TEM等技术对合成样品的形貌、物相、结构进行表征,研究了不同制备条件对ZnO纳米薄膜形貌及光电性能的影响。结果表明：初级结构ZnO纳米棒经铺膜退火处理后,表面可形成均匀的纳米粒子晶种层,为次级结构的生长提供活性位点。再次电沉积后,生成的分级有序ZnO纳米结构具有更大的比表面积,大幅度提高染料的吸附量,相比于初级纳米结构其光电转换效率提高54%左右(由0.52%增大至0.80%)。     

高温煅烧氢氧化铝生产中α-Al2O3定量转变的影响因素探究

为探究煅烧过程不同因素对α-Al₂O₃定量转变的影响规律及其机理,并确定制备特定α-Al₂O₃含量的最佳制备条件,将4N级氢氧化铝在不同温度、升温速率以及保温时间下进行煅烧。对煅烧后的样品进行定性定量分析,采用响应曲面分析法建立优化模型,并通过实验进行验证。研究结果表明：煅烧温度与保温时间是影响氧化铝相变过程α-Al₂O₃定量转变的主要因素,随着煅烧温度与保温时间的增长α-Al₂O₃的含量也在增加。以煅烧温度、升温速率、保温时间为影响因素,α-Al₂O₃含量值为响应变量建立模型,分别设定α-Al₂O₃含量取值为0.75、0.85和0.95进行验证,所建立模型预测结果与实验结果相差小于8%,证明所建模型有效。     

Direct mechanochemical conversion of celestite to SrCO3

The celestite concentrate obtained from Barite Mining Company (Sivas-Turkey) was converted to strontium carbonate using sodium carbonate in a planetary ball mill operated both in dry and wet modes. After wet planetary milling of celestite concentrate and sodium carbonate mixture, solid strontium carbonate and soluble Na₂SO₄ were obtained. The conversion reaction were followed by dissolution and sulphate analyses after high-energy milling operations. The 10, 20 and 40 min of wet milling experiments were performed in a planetary mill and the results showed that over 90% of dissolution and conversion of initial celestite to strontium carbonate was achievable by high-energy milling.     

球磨工艺对FeSiAl合金的制备和电磁性能的影响

以Fe,Si,Al为原料,采用高能球磨技术制备了FeSiAl合金粉末,研究了不同球料质量比,球磨时间对粉末的相结构,形貌和微波电磁性能的影响。结果表明： FeSiAl完成合金化的球料质量比为40:1,球磨时间为100h。随着球磨时间的增加,粉体的磁导率增加,而介电常数得到了降低,因而阻抗匹配更加优异。FeSiAl合金体积分数为35%的吸波材料,在厚度2mm时,在8.5GHz处,具有较低的反射率(-18.3dB)。     

Formation of TIB2 from rutile by room temperature ball milling

A mixture of rutile, boron oxide and magnesium has been ball milled together with the intention of inducing a reaction to form titanium diboride. The resultant powders were examined by differential thermal analysis, isothermal annealing and X-ray diffraction to determine the effect of milling on the formation of TiB₂. Complete reaction was found to occur in the mill between 10 and 15 h forming TiB₂ and MgO with no residual Mg. The unwanted phase, MgO, was readily removed by leaching in acid leaving a fine powder composed of aggregates of TiB₂. The feasibility of using this relatively simple, low technology route to value add for minerals is also discussed.     

云锡锡铜共生矿二、三段磨矿中钢球尺寸的选择

用工业试验验证了实验室钢球尺寸优化的结果,表明云锡公司选矿厂磨矿采用的Ф80mm钢球偏大,精确化的钢球尺寸应为15-30mm.钢球尺寸精确化后能提高细磨效率,改善产品特性,二、三段磨机技术效率提高均在15个百分点以上;钢球消耗大幅度下降,二、三段钢球单耗分别下降31．94％及28．87％;回收率及精矿品位均提高3个百分点左右。工业试验表明,钢球尺寸精确化对锡铜共生矿细磨是行之有效的。     

The influence of attrition milling on carbon dioxide sequestration on magnesium–iron silicate

Present work evaluates the structural changes in olivine (Mg,Fe)₂SiO₄ (deposit Åheim, Norway) generated by mechanical treatment as well as its adsorption properties for carbon dioxide. The high-energy attrition milling was applied for mechanical activation. Identification of the mechanically-induced changes in the mineral was carried out applying various techniques: scanning electron microscopy, Mössbauer spectroscopy, specific surface measurements, carbon dioxide adsorption and Fourier-transformed infrared spectroscopy. The observed changes in the physico-chemical properties illustrate the possibility of the applied activation to modify the surface and/or bulk properties of olivine. Sensitivity for atmospheric CO₂ sequestration as well as sequestration of CO₂ by chemisorption can be derived from the obtained results.     

球磨立磨矿渣粉的粉体特征分析

用激光粒度分析仪对球磨和立磨制成的矿渣粉粉体特征进行分析,结果表明:两种粉磨方式的矿渣粉颗粒分布都符合RRSB分布,n值可以很精确地反映粉体分布的宽窄程度,球磨矿渣粉粒度分布比立磨宽;与Fu ller曲线相比,矿渣粉的细颗粒和粗颗粒含量偏少,中间颗粒含量偏多。立磨与球磨相比,立磨矿粉细颗粒和粗颗粒部分距离Fu ller曲线都较远;粒度表征参数中,比表面积和中位径都可以很好表征两种矿渣粉的总体粗细程度。     

The effects of LiOH and NaOH on the carbonation of SrSO4 by dry high-energy milling

In this work, the effects of alkaline hydroxides (NaOH and LiOH) on the direct mechanochemical carbonation using dry high-energy milling of celestine (SrSO₄) under CO₂ atmosphere was investigated with X-ray diffraction (XRD), infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and carbon analyses. It was observed that SrSO₄ was not directly carbonated by dry high-energy milling under CO₂ atmosphere without LiOH or NaOH additives. Direct mechanochemical SrCO₃ formation was observed during milling of the SrSO₄ and NaOH mixture under CO₂ atmosphere, and it was shown that a minimum 50% of the initial SrSO₄ was mechanochemically carbonated in the presence of NaOH and CO₂ gas. LiOH does not stimulate the direct carbonation. However, it was observed that washing of the milled mixture with water resulted in strontium carbonate (SrCO₃) formation because of the enhanced dissolution of Li₂CO₃ and SrSO₄, promoted by the activation effect of high-energy milling. Depending on the alkaline hydroxide used during the milling, strontium carbonates with different space group settings were formed, which have different (split or single) main carbonate absorption bands.     

用机械合金化制备镍基固溶体细微粉末的工艺研究

用机械合金化方法制备了镍基固溶体粉末, 探讨了机械合金化球磨工艺对镍基混合粉末粒度的影响, 在以酒精为过程控制剂, 转速为180 r/min, 球磨时间为20 h, 球料比为40∶1 时, 可获得粒度约为3 μm 的镍基合金粉末。     

纳米CeO2/Zn金属基复合材料的制备

介绍了采用高能球磨法制备出纳米CeO2/Zn、纳米CeO2/A l复合粉末,用粉末冶金真空热压烧结制备出纳米CeO2/Zn、纳米CeO2/A l复合材料块的工艺方法。     

Preparation of iron oxide nanoparticles by mechanical milling

Hematite powder (Fe₂O₃) was ground in a planetary mill and the milling time and mill rotational speed were varied at three levels. The ground products were then characterized, to investigate size reduction and the mechanochemical effect, by X-ray diffraction (XRD) line broadening, specific surface area (SSA) and particle size and morphology analysis. The line broadening technique was used to determine the degree of crystallinity, crystallite size and lattice strain. The milled hematite particles revealed particle sizes in the nanometer range with a specific surface area of 14.96 m²/g. All milled samples exhibited the mechanochemical effect, where the degree of crystallinity ranged from 9.37 to 49.8%. The minimum crystallite size obtained was 17.1 nm with a degree of crystallinity of 9.37% when hematite was ground at 600 rpm for 10 h.