等离子体还原四氯化硅生产三氯氢硅试验

进行了用直流放电等离子体法还原四氯化硅生产三氯氢硅的试验,反应器的功率达到30 kW,三氯氢硅单程收率超过了60%,每生产1 kg三氯氢硅耗电4.55 kW.h。通过计算得到了氢气解离度、电离度与温度的关系,归纳出氢气的比定压热容随温度变化的函数,根据试验结果确定了氢气和四氯化硅的最佳进料配比。     

四氯化硅制备三氯氢硅技术研究进展

阐述了多晶硅行业的生产背景和现状,概述了由四氯化硅和二氯二氢硅反歧化反应制备三氯氢硅的反歧化方法和四氯化硅氢化制备三氯氢硅的氢化方法,氢化方法主要包括热氢化法、低温催化氢化法、冷氢化法、氯氢化法、等离子体氢化法等,重点归纳了新型氢化技术低温催化氢化法,并介绍了反歧化方法和多种氢化方法在多晶硅生产过程中的应用,通过对各种方法综合性的分类与讨论,指出了现存方法的优缺点,并对各种方法的应用前景进行了展望。     

四氯化硅制备三氯氢硅新工艺研究

四氯化硅是光伏产业的副产物,对环境产生严重污染。以四氯化硅合理化利用作为研究对象,分析了四氯化硅制备三氯氢硅主要工艺方法的优缺点,找出最佳的工艺方法。对直流放电等离子法还原四氯化硅工艺进行实验研究,找出最佳的工艺条件获得最大的收率。     

光化法去除四氯化硅中三氯氢硅的实验研究

以市售粗四氯化硅为原料,对光化法去除四氯化硅中常见的三氯氢硅杂质进行了研究。分析了以波长为330~380 nm的紫外线为光源,进行三氯氢硅的光化反应过程中,影响光化效果的主要因素及其相互之间的关系。研究表明:光化时间随着原料量的增加而增加;光化时间随着光照强度的减少而增加;氯气与三氯氢硅物质的量比至少大于22∶1;氯气与三氯氢硅物质的量比存在临界值,小于此值时光化时间随氯气与三氯氢硅物质的量比的增大而减少,大于此值时光化时间反而有所增加,光照强度越大此值越小。     

Kinetics of the reduction of nickel oxide by hydrogen

The reaction model for the reduction of NiO pellets by hydrogen has been postulated to consist of two simultaneous reactions, first, a reaction between NiO and hydrogen gas adsorbed on NiO, and second, a reaction at the boundary between the two solid phases NiO and Ni with hydrogen adsorbed on nickel. The first reaction rate varies with the 0·43 exponent of hydrogen pressure indicating a surface reaction with adsorbed hydrogen where surface coverage increases with pressure. The second reaction rate is nearly independent of pressure indicating that the surface of nicle is nearly completely covered with adsorbed hydrogen at atmospheric pressure and above. Reaction rates have been established as a function of temperature and pressure. At temperatures below 300°C the resistance offered to internal diffusion was negligible for pellets 4·3 mm in diameter but became significant at higher temperatures.     

Kinetics of hydrogen reduction of nickel sulfide

The hydrogen reduction of powdered nickel sulfide (Ni₃S₂) at atmospheric pressure in the temperature range 475 to 630 °C has been experimentally investigated. The true intrinsic kinetics of this reaction were obtained, under conditions such that the topochemical shrinking core model in the chemical control regime could be applied. In the temperature range 475 to 530 °C, the rate constant could be expressed by the following equation: Above 530°C, whisker formation of nickel metal was observed. It was also shown that the thermal history of the powder had an important bearing on the results obtained ? in general, preheating led to lower reduction rates.     

Kinetics of hydrogen reduction of cobalt sulfide

The hydrogen reduction of cobalt sulfide (Co₉S₈) at atmospheric pressure in the temperature range 600–800°C has been experimentally investigated. When sulfide pellets were used, the rate constants were overestimated. The true intrinsic kinetics of this reaction were obtained from another set of experiments using sulfide powder, under conditions such that the topochemical shrinking core model in the chemical control regime could be applied. In the temperature range 600–737°C, the rate constant for the powder reaction could be expressed as: k = 15,600 exp (–27,800/RT) Above 780°C, cobalt metal whiskers were formed, and this led to swelling and cracking of pellets.     

铬酸钠氢还原反应动力学

引言 铬为重要战略资源,铬及其化合物在国民经济中有不可替代的广泛应用.Cr2O3为铬盐工业主要产品之一,广泛有于、颜料、磨料、治金原料、耐火材料、有机合成催化剂、热喷涂材料等领域.     

Kinetics of hydrogen reduction of cobalt sulfide

The hydrogen reduction of cobalt sulfide (Co₉S₈) at atmospheric pressure in the temperature range 600–800°C has been experimentally investigated. When sulfide pellets were used, the rate constants were overestimated. The true intrinsic kinetics of this reaction were obtained from another set of experiments using sulfide powder, under conditions such that the topochemical shrinking core model in the chemical control regime could be applied. In the temperature range 600–737°C, the rate constant for the powder reaction could be expressed as: Above 780°C, cobalt metal whiskers were formed, and this led to swelling and cracking of pellets.     

Kinetics of reduction of solid copper sulphate by hydrogen and carbon monoxide

Cupric sulphate is reduced to metallic copper by H₂ at 225° to 400° with formation of Cu₂SO₄ as an intermediate product. Under the present experimental conditions, the reduction followered the equation k = 1 — (1 — R)^1/3, where R is the fraction reacted at time t and k is the velocity constant. The activation energy of the overall process in this temperature range lies between 15 and 17 Kcal/mole. Reduction by CO takes place at 400° to 650°C with formation of Cu₂SO₄ and Cu₂O and the activation energy in this temperature range lies between 24 and 29 Kcal/mole. Reduction in both cases is exothermic.     

硅粉质量对合成法生产三氯氢硅的影响

分析了硅粉质量对三氯氢硅合成的影响,包括:硅粉粒径对三氯氢硅收率和转化率的影响,硅粉含水量和杂质铝含量对系统运行稳定性的影响,以及杂质含量对合成三氯氢硅产品质量的影响。     

四氯化硅和四氟化硅的研究比较

SiCl4主要是作为改良西门子法生产多晶硅的副产物得到,SiF4主要是作为磷肥工业的副产物氟硅酸分解得到,但是二者纯度都不能满足生产多晶硅的要求,需进行分离纯化得到高纯物质。本文针对SiCl4和SiF4的物化性质、合成工艺、精制方法、应用前景等方面做了探讨和比较,指出SiF4比SiCl4更具应用前景。     

硅和四氯化硅耦合加氢反应体系的热力学分析

基于Gibbs自由能最小原理,对硅和四氯化硅（SiCl₄,STC）耦合加氢反应体系进行了热力学分析。通过化学平衡产物组成分布的分析,确定了反应体系主要产物为三氯硅烷（HSiCl₃,TCS）、二氯硅烷（H₂SiCl₂,DCS）、盐酸（HCl）,并构造了3个相应的独立反应,讨论了对应的反应热（ΔrHθm）、自由能（ΔrGθm）和平衡常数（Kθp）与温度的关系。计算所采用的温度为673~923 K,压力为101.325 ~2 026.5 kPa,原料H₂与SiCl₄物质的量比为1~5。结果表明,生成TCS和DCS的反应为体系随着温度升高,四氯化硅平衡转化率及三氯硅烷产率降低;高压和适中的原料配比（H₂与SiCl₄物质的量比）有利于四氯化硅转化率及三氯硅烷产率的提高。     

氯化亚铜催化四氯化硅和硅耦合加氢的机理研究

以氯化亚铜为催化剂、使用固定床反应器,对四氯化硅和硅耦合加氢反应进行反应历程中固体催化物种活性变化的机理研究。利用程序升温策略使Cu3Si在反应前完全生成,开启反应后观察到包含诱导期、稳定期、失活期的反应活性曲线,对诱导期的成因进行了讨论,认为Cu3Si在反应气氛下的氯化是形成活性中心的必要条件。使用惰性气体吹扫降温法制备了不同反应阶段的颗粒样品。利用SEM-EDS、XRD、XRF等研究了反应历程中表面形貌、晶型及体相组成的演化规律,提出了反应失活模型,认为颗粒表面形貌组成的变化导致扩散速率下降是失活的原因。     

四氯化硅的合成与精制

重点介绍了四氯化硅的制备及精制工艺。四氯化硅的工业制备方法主要有硅铁氯化法、废触体氯化法、硅氢氯化法、二氧化硅氯化法等,并分别介绍了各方法的特点。其精制方法主要有吸附法、反应法、精馏法以及这些方法的组合。通过采用2级精馏方法可得到光纤级高纯四氯化硅,同时介绍了高纯四氯化硅的充装和质量标准。此外,还简要介绍了四氯化硅的应用、经济概况及展望。     

氯化氢含水对生产三氯氢硅的影响

介绍了氯化氢含水对生产三氯氢硅的影响,并论述了减少氯化氢中水含量的一些措施。     

Kinetics of hydrogen reduction of sodium sulfate mixed with sodium titanate

The hydrogen reduction kinetics of solid sodium sulfate mixed with sodium titanate are studied in a thermogravimetric system. The conversion-time curves of the hydrogen reduction are sigmoidal in shape and are well described by the nucleation and growth model up to about 60% conversion. The reduction rate of this mixture is much faster than that of pure sodium sulfate. In the deceleratory conversion period, the reduction is controlled by gas diffusion through a product layer. Activation energies of 302 and 179 kJ/mol are obtained, respectively, for the nucleation and growth, and diffusion limited period. The influence of hydrogen concentration, steam concentration, sodium sulfate fraction, and sodium sulfide addition is also studied. A reaction mechanism is proposed for the hydrogen reduction in the solid state.     

向三氯氢硅合成工序输送氯化氢工艺的改进

介绍昊华宇航化工有限责任公司向三氯氢硅合成工序输送氯化氢过程中存在的问题,提出了改进措施.     

四氯化硅的制备工艺综述

对SiCl_4的传统工业生产方法(如工业硅氯化法、硅铁氯化法等)和新发展的制备方法(如硅藻土氯化法、工农业副产物制备SiCl_4)进行了分析比较研究,展望了SiCl_4制备工艺及应用的发展方向,指出利用硅藻土以及多晶硅副产物制备SiCl_4的途径前景广阔,而SiCl_4分离提纯技术是解决副产SiCl_4出路的关键。     

四氯化硅的制备工艺综述

对SiCl_4的传统工业生产方法(如工业硅氯化法、硅铁氯化法等)和新发展的制备方法(如硅藻土氯化法、工农业副产物制备SiCl_4)进行了分析比较研究,展望了SiCl_4制备工艺及应用的发展方向,指出利用硅藻土以及多晶硅副产物制备SiCl_4的途径前景广阔,而SiCl_4分离提纯技术是解决副产SiCl_4出路的关键。