全攀枝花钛精矿冶炼钛渣熔盐氯化技术应用分析

针对以全攀枝花钛精矿冶炼的钛渣中Ti O2含量低、钙镁含量高的特点,分析了其熔盐氯化工艺关键控制点,并分别以Ti O2品位为74%、78%的钛渣为原料,研究了熔盐氯化工艺生产过程控制,分析比较了不同钛渣原料对产品粗四氯化钛质量的影响及粗四氯化钛生产成本的影响。结果表明:以全攀枝花钛精矿冶炼的Ti O2含量为74%、78%的高钙镁钛渣为熔盐氯化原料时,氯化熔盐中Ti O2、C含量宜控制在3%左右,循环泥浆中固体杂质含量宜控制在200 g/L左右。与采用Ti O2含量为78%钛渣相比,采用Ti O2含量为74%钛渣生产时氯化熔盐温度和收尘室进口气体控制温度降低30~50℃,石油焦、氯化钠单耗和废盐、收尘渣量增加,粗四氯化钛产品中固体杂质和VOCl3、Si Cl4、Fe Cl3含量较低。采用Ti O2含量为74%的钛渣为原料熔盐氯化生产粗Ti Cl4比采用Ti O2含量为78%的钛渣成本降低5%~10%。     

熔盐氯化法制备粗TiCl_4过程热平衡控制研究

对TiO_2品位为74%的高钙镁钛渣物相组成及氯化行为、熔盐氯化生产粗四氯化钛过程的熔盐温度控制进行了分析。结果表明,在粗四氯化钛单炉产量为100t/d的条件下,通过合理调节返炉矿浆量,可将钛渣氯化过程的熔盐温度与混合炉气温度分别稳定控制在740～770℃与350～501℃,并产出平均固相含量4.06～4.1g/L的合格粗TiCl_4产品。     

攀枝花74%品位钛渣熔盐氯化研究

开展了攀枝花74%品位钛渣熔盐氯化制备四氯化钛的试验研究,考察了74%品位钛渣作为氯化原料时,氯化炉温度控制、熔盐成分控制和产品质量情况,并对不同品位钛渣熔盐氯化时技术经济指标进行了对比分析。研究表明:使用攀枝花74%品位钛渣熔盐氯化生产高品质海绵钛用四氯化钛工艺可行,与采用78%钛渣熔盐氯化相比,每吨粗四氯化钛可节约成本98.3元。     

熔盐氯化炉氯化反应最高理论温度及其引热措施的探讨

高钙镁钛渣熔盐氯化生产四氯化钛的问题之一是氯化反应放出较多的热量,如果这些热量不及时从氯化炉中引出,就会影响熔盐氯化生产的正常进行,也会影响四氯化钛的气相收尘和冷凝回收以及液体四氯化钛中泥浆的沉积等。     

钛渣中FeO对熔盐氯化过程的影响

研究了不同FeO含量钛渣的化学及物相组成以及FeO含量对熔盐氯化过程放热量、收尘渣量及成分、熔盐成分和产品质量的影响。结果显示:钛渣中主要物相是黑钛石、金红石和硅酸盐玻璃体。随着FeO含量增大,钛渣熔盐氯化放热量、收尘渣比例、熔盐中的FeCl_3和FeCl_2含量、产品中FeCl_3含量和固含量均有所增大。高FeO含量用于熔盐氯化制备四氯化钛工艺可行,但对氯化过程熔盐成分和收尘渣成分影响较大,应通过调整物料配比、排盐制度和矿浆喷淋制度等予以解决。     

干馏煤替代石油焦用于TiCl4生产的应用研究

采用干馏煤与石油焦的煤焦混合物为还原剂,在熔盐氯化法生产TiCl4过程中进行工业化生产试验,考察了采用干馏煤的影响及生产工艺参数的变化。结果表明：随着煤焦混合物中干馏煤比例的增加,钛渣和氯化钠单耗变化无明显的差异,氯化炉熔盐温度、炉顶烟气温度等都在控制范围内,验证了干馏煤在熔盐氯化中应用的可行性,降低了TiCl4生产成本。同时,生产过程中为避免熔盐温度控制偏高,当干馏煤与石油焦配比大于5︰5时,熔盐温度可按730~780 ℃控制;采用100%干馏煤时,熔盐温度可按720~760 ℃控制,为增强熔盐流动性,氯化钠的配比可适度增加。     

熔盐氯化炉稳态温度场有限元分析

分析了锦州钛业有限公司1#熔盐氯化炉的传热特征,利用ANSYS有限元分析软件建立了熔盐氯化炉稳态温度场有限元模型.计算结果显示熔盐氯化炉炉壳温度在30～50℃,熔盐最高温度747℃,这与现场实测数据相近;熔盐氯化炉的热流密度和温度梯度说明炉墙传热对稳态温度场的影响较小,而喷淋四氯化钛泥浆是影响氯化炉稳态温度场的最大因素,并依此提出了解决熔盐温度过高的措施.     

四氯化钛生产工艺研究

首先综述了近年来四氯化钛的生产工艺,并围绕氯化的准备阶段一配料部分进行了详细汇总。对氯化部分,原料高钛渣品位和杂质元素含量高低,决定了国内外不同生产厂家使用不同的氯化工艺：熔盐氯化和沸腾氯化。对这两种氯化的特点进行了总结。在精制部分,通过四种不同除钒方式的对比,阐述了每种方法的优缺点,指出今后精制除钒向矿物油和铝粉除钒的方向发展。     

沸腾氯化工艺在生产中的应用

介绍了以石油焦，高钛渣，氯气等作原料，采用沸腾氯化工艺生产粗四氯化钛的情况及改造革新后的成果。     

高钛渣加碳氯化反应热力学在熔盐氯化中的应用

通过对高钛渣各组分氧化物加碳氯化反应的热力学计算与分析,发现循环氯气中的氧气与石油焦的燃烧反应是影响熔盐氯化炉温度的主要因素,而炉温的稳定控制是提高熔盐氯化炉运行效率的关键;在900~1 500 K时,高钛渣加碳氯化热力学趋势表明:所有氧化物在氯化过程中全部转变为氯化物,但实际反应中Al2O3、尤其是SiO2仅有很小一部分被氯化,同时确定了此温度区间各组分氧化物加碳氯化难易顺序;热力学条件对TiO2和SiO2氯化率的影响近于一致,所以从热力学角度不能进一步有效降低SiO2的氯化率而减少TiCl4中Si含量。     

"Psychotherapy" Versus "Treatment".

Presents a comment on "Psychological treatments" (see record 2004-21168-001) by D. H. Barlow. Barlow proposed that we distinguish between the terms "treatment" and "psychotherapy." The author believes that not only is the distinction unnecessary, but that its implications could have negative consequences for the field of clinical psychology. It is the proposed distinguishing feature that treatments are "specifically tailored to the pathological process that is causing the impairment and distress" that is most problematic. Clinical psychology does not need a distinction that further exacerbates the split between researchers and practitioners. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Versatic10萃取分离微生物浸出液中钙镁和低含量镍钴

以Versatic10为萃取剂从含镍、钴、钙、镁离子的合成硫酸盐溶液中萃取分离镍、钴离子。在25℃、振荡强度200r/min、振荡时间4 min的条件下,Versatic10萃取镍、钴离子的最佳条件为:初始pH2.5、相比O/A=1/3、皂化率60%。用去离子水(pH=6.50)对负载有机相按相比O/A=1/1洗涤2次,钙、镁离子的共萃率均可降至0.5%以下。用2mol/L硫酸按相比O/A=1/1反萃时,镍、钴的反萃率均在99%以上。     

Crystallization of Co<Subscript>100-<Emphasis Type="Italic">x</Emphasis></Subscript>Pt<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>B<Subscript>10</Subscript>Si<Subscript>12</Subscript> amorphous metallic alloys

Alloys of Co_78-x Pt _x B₁₀Si₁₂ were produced using the melt-spin process in order to study the crystallization behavior and ensuing magnetic properties of the Co-Pt amorphous alloys as a function of the Pt content. We showed that when x>15, well below its stoichiometric composition, CoPt intermetallic compound crystallized in the amorphous alloy. Below this composition, the main crystallization product was Co with Pt dissolved in its lattice. The nucleation of CoPt greatly altered the crystallized microstructures and magnetic properties of the Co-Pt amorphous alloys during annealing. In spite of the nucleation of CoPt with its high magnetic anisotropy, the highest coercivity was obtained when x was 15, free of the CoPt grains. It was also concluded that the Pt addition, in general, triggered crystallization to occur at a progressively lower temperature.     

Re-determination of the crystal structure of Ca₂Y₈Si₆O₂₆ and study on the luminescent properties of Ca₂Y₈Si₆O₂₆:Tb³⁺

The crystal structure of silicate oxyapatite Ca2Y8Si6O26 was indexed as hexagonal,space group P63/m,a=0.93515 nm,c=0.67872 nm,α=β=90°,γ=120°,V=0.5138692 nm3.Three strong peaks located at 32.079o,32.595o,and 50.104o with d=2.7903,2.74649,1.8194 was in accordance with,(112),and(213) planes.The optimum concentration of Tb3+ in Ca2Y8Si6O26 to yield highest photoluminescence intensity was 10 mol.% of Y3+.The corresponding excitation spectrum consisted of an intense broad band from 220 to 260 nm.The photoluminescence measurements showed that the green emission originated from 5D4-7F5 was predominant in the measured range with strong doublet lines at 543 and 549 nm.     

Corrosion Behavior of Fe<Subscript>41</Subscript>Co<Subscript>7</Subscript>Cr<Subscript>15</Subscript>Mo<Subscript>14</Subscript>C<Subscript>15</Subscript>B<Subscript>6</Subscript>Y<Subscript>2</Subscript> Bulk Metallic Glass in Sulfuric Acid Solutions

An Fe₄₁Co₇Cr₁₅Mo₁₄C₁₅B₆Y₂ bulk metallic glass with a diameter of 5 mm was prepared with the copper-mold-casting method. The corrosion resistance of this amorphous steel in sulfuric-acid solutions was determined by electrochemical measurements. The passive film formed on the surface of the alloy after immersion in the 0.5-mol/l H₂SO₄ solution for 1 week was analyzed by X-ray photoelectron spectroscopy (XPS). Electrochemical measurements show that the corrosion resistance of the amorphous steel in the 1 mol/l-H₂SO₄ solution is superior to a stainless steel (SUS 321), and is almost the same as Ti6Al4V, which shows that the amorphous steel has an excellent corrosion resistance in sulfuric-acid solutions. As the concentration of the sulfuric-acid solutions increases from 0.5 mol/l to 4 mol/l, the corrosion resistance of the amorphous steel decreases. The XPS result reveals that a bilayer structure of protective film formed on the surface of the amorphous steel in a H₂SO₄ solution. The compositions of the inner part of the film are MoO₂, Cr₂O₃, CoO, and FeO, and those of the outer film are MoO₃, Cr(OH)₃, Co(OH)₂, and Fe(OH)₃.     

Magnetic properties and magnetocaloric effects of manganite (La_0.8Ho_0.2)_2/3Ca_1/3MnO₃ and (La_0.5Ho_0.5)_2/3Ca_1/3MnO₃

We reported the magnetic properties and magnetocaloric effects(MCE) of(La0.8Ho0.2)2/3Ca1/3MnO3 and(La0.5Ho0.5)2/3Ca1/3MnO3 nanoparticles by sol-gel technique.With this method,we were able to obtain the samples with particle diameters ranging from 50 to 200 nm.In the(La1-xHox)2/3Ca1/3MnO3 compound,an external magnetic field induced a magnetic transition from an paramagnetic phase to a ferromagnetic phase above Ts=105-135 K,leading to magnetocaloric effects.The maximum value of ΔSM was 1.19 J/(kg·K) at 100 K and 2.03 J/(kg·K) at 152 K for a magnetic field change of 5 T.Because both samples had large relative cooling power(RCP) and wide δTFWHM,the study on systems with the(La1-xHox)2/3Ca1/3MnO3-related magnetic transitions may open an important field in searching good magnetic materials.     

A review of rare-earth oxide films as high k dielectrics in MOS devices——Commemorating the 100th anniversary of the birth of Academician Guangxian Xu

Recently,rare-earth oxide films have attracted more and more attention as gate dielectrics in metaloxide-semiconductor(MOS)devices,showing the advantages of high dielectric constant(k value),large band gap(Eg)and outstanding physical and chemical stability in contact with silicon substrates.This paper reviews the recent development of rare earth oxide-based gate dielectric films.Aiming at the problem that k value of rare earth oxides(REOs)is generally inversely proportio nal to the band gap value,one of the biggest technical obstacles of high k films,we reviewed three strategies reported in recent papers,namely doping modification,nitriding treatment and multilayer composite,which can provide some insights for long-term development of MOS devices in integrated circuit(IC).     

Effect of Ce<Subscript>2</Subscript>O<Subscript>3</Subscript> on Structure,Viscosity, and Crystalline Phase of CaO-Al<Subscript>2</Subscript>O<Subscript>3</Subscript>-Li<Subscript>2</Subscript>O-Ce<Subscript>2</Subscript>O<Subscript>3</Subscript> Slags

Aiming at devising new mold flux for Ce-bearing stainless steel, a fundamental investigation on the effect of Ce₂O₃ on properties of the CaO-Al₂O₃-Li₂O-Ce₂O₃ slag was provided by the present work. The results show that adding Ce₂O₃ could decrease the viscosity of the slag due to its effects on decreasing the polymerization of the slag. The crystalline process was restrained by increasing the content of Ce₂O₃, and the crystalline phases also can be influenced by the slag structure. The crystalline phases were transferred from LiAlO₂ and CaO to LiAlO₂ and CaCeAlO₄ with the addition of Ce₂O₃ to the slag, which could be well confirmed by the structure of the unit cell of the crystals.