Separation of aluminosilicates and diaspore from diasporic-bauxite by selective flocculation

The flocculation tests of four pure minerals (diaspore, kaolinite, illite, pyrophyllite) and bauxite ore were investigated by the sedimentation. The dispersion behavior of the four pure minerals shows a very good consistency with the variation of zeta potential. The concentrate with the mass ratio of Al2O3 to SiO2 (m(Al2O3)/m(SiO2)) 8.90 and the recovery of Al2O3 86.98% is obtained from bauxite ore (m(Al2O3)/m(SiO2)=5.68) in pH range of 9.5-10.0 by using sodium carbonate (5 kg/t) and sodium polyacrylate (7 g/t) as dispersant and flocculant respectively. Sodium carbonate acts as both pH modifier and favorable dispersant for aluminosilicates. The high performance of sodium polyacrylate on flocculation for diaspore is contributed to the carboxyl of sodium polyacrylate that interacts with active Al sites on diaspore by chemical absorption, and the hydrogen bond effects between hydroxyl group of macromolecule and surface Al--OH on diaspore to accelerate the sedimentation of diaspore.     

电容式非制冷红外焦平面阵列设计及优化

提出一种基于MEMS工艺弯折双材料悬臂梁结构的电容式非制冷红外焦平面成像阵列（FPA,Focal Plate Array）。并利用软件CoventorWare对器件的物理学特性进行有限元模拟分析。发现FPA的温度响应度和位移响应度与辐射能量呈线性关系;得到热时间常数、位移、温度灵敏度与铝膜与二氧化硅厚度比的关系,并得出当比率为0.5～0.6时位移响应最大,100μm×100μm和50μm×50μm两种尺寸器件的位移灵敏度峰值分别为0.061nm/pW.μm^-2和0.008nm/pW.μm^-2;随着器件尺寸的增大,其探测能力增强,瞬态响应降低;计算了吸收面与探测极板间的吸合附电压,得到100μm×100μm面板的吸附电压为3.625V～3.750V之间,50μm×50μm面板的吸附电压为10.250V～10.375V之间,以及器件尺寸与吸附电压间的关系.     

Synthesis of N, N-diethyl dodecyl amine and its flotation properties on bauxite

N, N-diethyl dodecyl amine（DEN12） was synthesized from dodecyl amine, formic acid and acetic aldehyde. The collecting property of DENI2 on diaspore, kaolinite and illite was investigated by flotation test and infrared spectrum. The results show that in the presence of 2.0× 10^-4 mol/L DEN12, the recoveries of kaolinite and illite are all higher than 78% and the recovery of diaspore is 50% in the pH range of 5.5-6.0. The mass ratio of A1203 to SiO2 in concentrate obtained from separation artificial mixture is higher than 10, suggesting that DEN12 can be used as a collector to separate the aluminosilicates from diaspore in bauxite ores at the pulp pH below 8. The measurements of the infrared spectrum approve that the action between aluminosilicates and tertiary amine collector is strong electrostatic adsorption and that of diaspore is weak electrostatic adsorption.     

ZrO＿2—20wt％Al_2O_3陶瓷复合材料显微结构的TEM研究

用透射电镜研究了（ＺｒＯ２＋ｘｍｏｌ％Ｙ２Ｏ３）－２０ｗｔ％Ａｌ２Ｏ３陶瓷复合材料的显微结构，发现在Ｙ２Ｏ３含量为２．０ｍｏｌ％～２．５ｍｏｌ％成分下，较大的（可达１μｍ）未转变颗粒仅限于嵌在Ａｌ２Ｏ３晶内的ＺｒＯ２（ｔ），当Ｙ２Ｏ３含量为３．０ｍｏｌ％时不嵌在Ａｌ２Ｏ３晶内的ＺｒＯ２（ｔ）颗粒（可达１．３μｍ）也可保持四方相结构。因此３．０ｍｏｌ％Ｙ２Ｏ３成分下四方相的急增及其最佳相交增韧效果归因于基体弹性模量的增加和适量稳定剂（Ｙ２Ｏ３）加入的共同作用结果。     

Effects of minerals in ferric bauxite on sodium carbonate decomposition and volatilization

Direct reduction is an emerging technology for ferric bauxite utilization. However, because of sodium volatilization, its sodium carbonate consumption is considerably higher than that in ordinary bauxite processing technology. TG-DSC and XRD were applied to detecting phase transformation and mass loss in direct reduction to reveal the mechanism on sodium volatilization. The results show that the most significant influence factor of ferric bauxite on sodium volatilization in direct reduction system is its iron content. Sodium volatilization is probably ascribed to the instability of amorphous substances structure. Amorphous substances are the intermediate-products of the reaction, and the volatilization rate of sodium increases with its generating rate. These amorphous substances are volatile, thus, more sodium is volatilized with its generation. A small amount of amorphous substances are generated in the reaction between Na2CO3 and Al2O3; thus, only 3.15% of sodium is volatilized. Similarly, the volatilization rate is 1.87% in the reaction between Na2CO3 and SiO2. However, the volatilization rate reaches 7.64% in the reaction between Na2CO3 and Fe2O3 because of the generation of a large amount of amorphous substances.     

SAPO-34分子筛的制备与表征

采用水热合成法制备SAPO-34分子筛,并考察了SiO2/Al2O3、H2O/Al2O3、晶化温度对SAPO-34分子筛合成的影响,进一步采用XRD、粒度分布、SEM对合成的分子筛进行表征.实验结果表明,当物料摩尔配比为n(Al2O3)∶n(P2O5)∶n(SiO2)∶n(TEA)∶n(H2O)=1∶1∶0.8∶3∶60,晶化温度为200℃,晶化时间为48 h时,合成的SAPO-34分子筛相对结晶度高,粒度分布较均匀,平均粒径为7.5μm.     

Al/Y_2W_3O_(12)复合材料的制备、热膨胀及电性能研究

采用固相法制备Al/Y_2W_3O_(12)复合材料,研究了Al与Y_2W_3O_(12)以不同质量比合成样品的特性。X射线衍射表明:样品只含有Al和Y_2W_3O_(12),不存在Al对Y的取代。SEM和EDS分析表明:小颗粒Y_2W_3O_(12)嵌入在块状Al基底中,为嵌入式复合结构。热膨胀性能和电导率测试分析表明:当Al与Y_2W_3O_(12)的质量比7∶3时,Al/Y_2W_3O_(12)样品的线膨胀系数14.76×10-6/K(RT~600℃)约为Al的一半,呈现良好的导电性,其导电率为18.2 S/m可达Al的电导率的1/2,且Al/Y_2W_3O_(12)样品几乎不表现出吸水性。研究认为,该复合材料具有低膨胀和较高导电性是由于其特有的嵌入式结构所致。     

新型无机高分子絮凝剂—聚合硅酸铝的研制及应用

聚合硅酸铝是一类性能优良的无机高分子絮凝剂。以水玻璃,硫酸铝,硫酸为原料,通过考察不同ＰＨ值条件下硅酸溶液的胶凝时间,Ａｌ＾３＋与ＳｉＯ２摩尔比等因素对ＰＳＡＡ产品应用性能的影响,确定了ＰＳＡＡ的最佳合成条件为ＰＨ３－４,Ａｌ＾３＋与ＳｉＯ２摩尔比０．８－１．２,活化时间３０－５０ｍｉｎ。     

Simple method to rapidly fabricate chain-like carbon nanotube films and its field emission properties

A simple process to fabricate chain-like carbon nanotube (COT) films by microwave plasma-enhanced chemical vapor deposition (MPCVD) was developed successfully. Prior to deposition, the Ti/Al2O3 substrates were ground with Fe-doped SiO2 powder. The nano-structure of the deposited films was analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. The field electron emission characteristics of the chain-like carbon nanotube films were measured under the vacuum of 10-5 Pa. The low turn-on field of 0.80 V/μm and the emission current density of 8.5 mA/cm2 at the electric field of 3.0 Vμ/m are obtained. Based on the above results, chain-like carbon nanotube films probably have important applications in cold cathode materials and electrode materials.     

The Mixed-Alkali Effect on The Resistance of Glass to Water

Based on the composition of float glass, the resistance of glass to water, in which a small amount of K2O (0-1.0 wt% ) was substituted for equivalent amount of Na2O, was investigated by means of glass grains testing. The components extracted from the glass and total alkalinities in extraction solution were determined by atomic absorption spectroscopy and neutralizing method, respectively. The composition of the glass was 14.4 K2O Na2O, 4.0MgO, 8.2CaO, 1.4Al2 O3, 72.0 SiO2, and the minimum extraction ratio of oxides (maximum durability) occurred at a K2 O/Na2O ratio of 0.051( by weight) due to the presence of the mixed-alkali effect. The relative extraction ratio of alkali oxides (R2O) was greater than that of alkaline earth oxides (RO) . By means of mixed-alkali effect and lowing relative contents of R2O in the glass, the resistance of float glass to water was improved and its mildew-proof ability was therefore increased.     

掺钕透明微晶玻璃的析晶动力学和显微结构

采用传统熔体冷却法制备了45Si O2-25Al2O3-15CaF2-5Na2O-10NaF-1Nd2O3体系玻璃,并通过优化热处理工艺获得了透明氟氧化物微晶玻璃。采用析晶动力学分析了45Si O2-25Al2O3-15CaF2-5Na2O-10NaF-1Nd2O3体系玻璃的析晶机制,并通过DSC、XRD和SEM等方法研究了热处理制度与玻璃析晶行为和显微结构的关系。研究表明,该体系玻璃的析晶过程主要受扩散控制,其主晶相为CaF2,析晶活化能为325.51 kJ/mol,晶粒尺寸随晶化温度升高逐渐长大,晶粒数量随保温时间延长逐渐增多。通过优化热处理制度,获得了晶粒尺寸约为40 nm,晶相含量约为30%的透明微晶玻璃。     

熔体温度处理对磷铜变质Al-20%Si组织的影响

研究熔体温度处理工艺（包括熔体混合及熔体过热处理）与磷铜变质对Al-20%Si合金中硅相形态的影响。结果表明：在本试验条件下,单纯添加磷铜变质剂的Al-20%Si合金,当添加其合金质量的0.4%时,初晶硅由未变质前的97μm减小到65μm,减小了33%;当将熔体温度处理工艺与磷变质处理相结合时,此时Al-20%Si合金中的初晶硅尺寸减小至36μm,减小了62%,且钝化现象显著,弥散分布于α-Al基体上,共晶硅也由未变质前的长针状变为短纤维状和点状。     

高反射红外辐射涂料的制备与性能

选用Al2O3、ZnO和SiO2为耐火骨料,加入4种高反射率材料,分析高反射率材料的含量对反射红外辐射涂料反射率的影响.利用正交试验设计,确定涂料最佳配方.实验结果表明：当加入空心微珠30%、TiO27%、Cr2O311%和ZrO212%时,涂料的热反射率达到92%.     

Measurement of refractive indices and thermal refractive index coefficients of Cr~(3+) Be_3Al_2Si_6O_(18) by auto-collimation method

Emerald [Cr3+︰Be3Al2Si6O18] is a negative uniaxial crystal belonging to the hex-agonal system with a space group 26(6/).hDPmccOwing to transitions of the Cr3+ ion, emerald crystal is an efficient wide band tunable laser medium among many Cr3+-doped lasing mediums[1]. Emerald has a more complex crystal structure and a weaker crystal field than alexandrite. The former has an emission cross-section approximately four times that of the latter, a melting point of 1470℃, 400癈 lower than the l…     

镍催化剂对加氢石油树脂性质的影响

分别以ＳｉＯ_２,Ａｌ_２Ｏ_３和Ａｌ_２Ｏ_３－ＳｉＯ_２复合材料为载体制备了Ｎｉ基石油树脂加氢催化剂（Ｎｉ／ＳｉＯ_２,Ｎｉ／Ａｌ_２Ｏ_３和Ｎｉ／Ａｌ_２Ｏ_３－ＳｉＯ_２）,并在微型加氢反应装置上对石油树脂进行加氢脱色活性评价。评价结果表明,Ｎｉ／ＳｉＯ_２,Ｎｉ／Ａｌ_２Ｏ_３和Ｎｉ／Ａｌ_２Ｏ_３－ＳｉＯ_２催化剂均能达到石油树脂脱色的效果,以Ｎｉ／ＳｉＯ_２为石油树脂加氢催化剂的产品软化点下降幅度最小,下降４℃,以Ｎｉ／Ａｌ_２Ｏ_３－ＳｉＯ_２为石油树脂加氢催化剂得到的加氢石油树脂软化点下降幅度较大。     

Study on optical constants inversion and infrared transmission characteristics of aerosol particles

Based on the experimental infrared spectral transmittances,an inverse model has been developed to determine the optical constants of the aerosol particles (SiO2 and Al2O3).Combined with the Mie theory and Kramers-Kronig (K-K) relations,the complex refractive indices of the SiO2 and Al2O3 particles are retrieved.The effects of the measurement errors on the inverse results are also investigated.With the optical constants inversed from the experiment,the discrete ordinate method (DOM) is used to calculate the infrared transmission characteristics of the aerosol particle cloud.Considering the multi-scattering and self-emission of the particles,the equivalent transmittance ratio (ETR) is suggested to evaluate the infrared transmission characteristics of the aerosol particles.Particular attention is given to analyze the effects of the volume fraction and diameters on infrared transmission characteristics.When the volume fraction is larger than 0.001,the particle diameter has little effect on the infrared transmission characteristics.For the uniform monodisperse particles in the detection waveband range of 3-5 μm and 8-12 μm,there exists a critical diameter where the ETR reaches the minimum value.In addition,the ETR of 3-5 μm is smaller than that of 8-12 μm with the same volume fraction and particle diameter.     

适用于谷物干燥的红外辐射陶瓷材料

以Al2O3、SiO2为主体原料,Fe2O3、CuO、Y2O3为辅助原料,经高温烧结合成了适用于谷物干燥的红外辐射陶瓷材料(莫来石及掺杂莫来石)。并测定了其在2.5~15μm波段的红外辐射率在0.845~0.933之间。利用正交实验设计,以红外辐射率为指标进行了配方的优化设计,经过分析得到最佳质量分数的配方方案:主体原料:莫来石子90%(Al2O3与SiO2的摩尔比为3∶2);辅助原料:Fe2O3为2.5%、CuO为5%、Y2O3为2.5%。     

金佛寺岩体地球化学特征及成因

金佛寺岩体是一个晚志留世侵入于北祁连造山带中的花岗质岩体,主要由黑云母二长花岗岩,黑云母 钾长花岗岩和黑云母石英二长岩组成。岩体中岩石w(SiO2)为67.09%～74.97%,w(K2O)/w(Na2O)为1.18 ～1.83,w(MgO),w(TFeO),w(CaO)和w(Al2O3)随w(SiO2)增大而减小,而w(K2O)增大。ANCK为1.06～ 1.24,均属铝过饱和,σ为1.25～2.48,属钙碱性系列。.REE为(21.36～254.9)×10-6,与w(SiO2)呈负相关 关系,多数稀土配分曲线相似:轻稀土分异明显大于重稀土。δ(Eu)为0.64～0.19,铕的亏损随w(SiO2)增大而 增大。Ni,Cr,Co,Sc,V和Sr随w(SiO2)增大而变小,Rb增大,Th和Th/U比值呈正相关,Ta与Nb/Ta呈负相 关。岩体的主量元素、稀土和微量元素的变异主要由深熔过程引起,而不是结晶分异作用引起的。主要源岩是 富长英质的,而不是富泥质的,其矿物组合可能是普通角闪石+黑云母+斜长石+钾长石+石英,与北大河岩群 很相似。     

MoP/TiO_2-SiO_2-Al_2O_3的制备及加氢脱芳性能研究

采用溶胶—凝胶法及共浸渍法制备了TiO2-SiO2-Al2O3复合载体,并用共浸渍法制备负载型MoP/TiO2-SiO2-Al2O3催化剂。XRD结果表明,TiO2的晶相衍射峰呈锐钛矿,SiO2则大多以无定型态分散于γ-Al2O3晶体表面。通过原位还原技术对催化剂进行还原处理,在连续固定床反应器上进行活性评价,结果表明,钛硅铝物质的量比对催化剂的活性有很大的影响,在温度为360℃,压力为3MPa,液时空速为1h-1,氢油体积比为500∶1的反应条件下,n（Ti）∶n（Si）∶n（Al）为1∶1∶4,Mo负载量为20%时,MoP/TiO2-SiO2-Al2O3催化剂的加氢脱芳活性最高,达到65.6%。并且TiO2-SiO2-Al2O3三元复合载体比传统的γ-Al2O3和SiO2-Al2O3二元复合载体的活性分别提高了19.6%和13.6%。     

Effectiveness of sodium silicate as gangue depressants in iron ore slimes flotation

The recovery of iron from the screw classifier overflow slimes by direct flotation was studied.The relative effectiveness of sodium silicates with different silica-to-soda mole ratios as depressants for silica and silicate bearing minerals was investigated.Silica-to-soda mole ratio and silicate dosage were found to have significant effect on the separation efficiency.The results show that an increase of Fe content in the concentrate is observed with concomitant reduction in SiO2 and Al2O3 levels when a particular type of sodium silicate at a proper dosage is used.The concentrate of 58.89wt％ Fe,4.68wt％ SiO2,and 5.28wt％ Al2O3 with the weight recovery of 38.74％ and the metal recovery of 41.13％ can be obtained from the iron ore slimes with 54.44wt％ Fe,6.72wt％ SiO2,and 6.80wt％ Al2O3,when Na2SiO3 with a silica-to-soda mole ratio of 2.19 is used as a depressant at a feed rate of 0.2 kg/t.