板坯连铸机粘结漏钢的原因分析及解决措施

为了减少大板坯连铸机粘结及粘结漏钢的发生,对结晶器保护渣的消耗量、保护渣液渣层厚度及粘结的受力机理进行了研究和分析,认为保护渣消耗量低及保护渣液渣层厚度不够时容易产生粘结和粘结漏钢。通过采集现场的参数进行理论计算并与实际生产值进行对比,结果表明,保护渣的消耗量控制在0.4～0.6 kg/m2、保护渣液渣层厚度控制在10mm以上后,未发生粘结漏钢事故,且粘结发生次数降低了60%。     

攀枝花钛渣组合式流化床氯化制备TiCl4的研究

以攀枝花高钙、镁钛渣为原料,采用组合式流化床反应器进行氯化制备TiCl4的研究,试验结果表明:组合式流化床反应器具有较强的抗粘结能力,其设备单位面积的TiCl4产能达到38～76 t/(m2.d),为普通沸腾氯化反应器的1～3倍.     

渣焦反应对焦炭性状的影响

本文主要研究了渣—焦反应对焦炭性状的影响。结果表明随渣—焦反应的进行,钛渣将程度不同地粘结在焦炭上,但并不影响焦炭的比表面积,这是钛渣的重要特性之一。无论炉渣含钛与否,渣—焦反应对焦炭的抗压强度、显微强度、反应性等均无明显影响。     

提钒尾渣煤基回转窑法钙化还原脱钠研究

针对提钒尾渣中钠含量高,导致难以返回烧结-高炉流程进行回收利用的问题,提出基于煤基回转窑还原的提钒尾渣钙化还原脱钠技术路线,并在?1 m×10 m回转窑中试线进行半工业试验,主要研究了高温段还原温度、白灰配比、入窑吨球焦粉配比、高温还原时间对提钒尾渣脱钠的影响规律,同时对脱钠后球团性能和回转窑结窑情况进行分析。结果表明,在高温段温度为1 100～1 160℃,高温段时间为1.8～2 h,入窑吨球焦粉配比为800～1 000 kg,白灰配比为32.5%～41%的条件下,提钒尾渣脱钠率可达到80%以上,吨球焦粉实际消耗量为359 kg。窑内结块物主要由提钒尾渣球团粉末和焦粉灰分粉末组成,结块物呈疏松多孔状,由细颗粒相互粘结构成,窑转动过程会自动掉落,无明显结窑现象。     

91 MW循环流化床锅炉冷渣器优化改造探讨

针对91 MW循环流化床热水锅炉在运行过程中,因结构、安装等原因导致冷渣器在冷渣过程中发生构件磨损、细渣自流、排渣不稳定、联锁保护系统反应滞后等问题,通过现有技术措施对冷渣器系统进行优化改造,保证了冷渣器的可靠性,提高了机组的运行效率。     

硫铁矿烧渣直接还原回收有价金属

研究了采用回转短窑对硫铁矿烧渣进行焙烧以回收有价金属的方法,考察了不同的工艺条件对硫铁矿烧渣焙烧的影响。研究结果表明:在还原温度在1 250℃下、还原时间为60min下,硫铁矿烧渣得到充分的还原。金、银、铜、铅、锌的挥发率中试分别达到93.26%,82.20%,82.55%,88.53%和83.48%,此时球团的硬度可以达到2 100N。     

镁还原渣应用于循环流化床锅炉脱硫的试验

为能够有效降低发电厂煤炭脱硫的实际成本、降低脱硫过程中对环境所造成的污染。本文将会对镁渣应用于循环流化床锅炉脱硫性能及其前后的变化情况进行相关试验研究。通过研究结果发现,在实验室条件下,镁渣应用与脱硫试验后,在实际脱硫过程中,O_2、SO_2、以及镁渣量都将会对镁渣的脱硫反应性能造成影响,并且随着气体浓度与镁渣量的提升,该反应性能也将会随之上升。     

自然碱度铁矾渣含碳球团回收铁研究

铁矾渣是湿法炼锌过程中沉铁工艺产生的固态废渣,含有一定量的Fe和其它有价金属元素。为了回收铁矾渣中的Fe,开发了铁矾渣含碳球团转底炉直接还原-熔分工艺。通过自然碱度铁矾渣配加煤粉的方式进行直接还原,研究了不同工艺参数对铁矾渣中Fe回收的影响,并进行转底炉中试试验,取得良好效果。最佳工艺条件:还原温度1 100℃,还原时间30 min,wC/wO=1.2,此条件下铁矾渣含碳球团金属化率达到90.6%。中试试验金属化率为75%,铁的综合回收率达到85%。     

石煤钒矿循环流化床燃烧脱碳试验

对某石煤钒矿循环流化床燃烧脱碳进行了研究。经油枪点火后先用烟煤燃烧循环至床温850~880℃,然后进行了全石煤工况的燃烧试验,对石煤进行全面的燃烧参数监视和记录,对烟气、底渣、烟尘进行采样和分析。结果表明,循环流化床燃烧脱碳运行工况稳定、循环回路通畅,燃烧效率74.16%,底渣和烟尘中的含碳量都控制在3%左右,燃烧脱碳基本不会造成钒的损失。     

金属化球团的高温粘结机理及控制

对攀钢资源综合利用中试线试验生产中出现的高温金属化球团粘结问题进行分析,认为其粘结机理为低熔点的硅酸盐相粘结和钛赤铁矿的晶间固结,而金属化球团再氧化是这2种粘结的诱因。开展了不同防氧化方式对球团金属化率的影响试验,选用氮气保护方法进行了现场验证。结果表明:氮封方法可以有效防止高温金属化球团粘结,确保了金属化球团生产试验过程的顺利进行。     

沸腾焙烧高铜锌精矿的工艺研究及生产实践

为了进一步提高沸腾焙烧炉对高铜锌精矿的适应能力,在生产中尽量保证其他操作条件不变的基础上调整入炉料铜含量,剖析高铜锌精矿对沸腾焙烧的不良影响。依据铜在沸腾焙烧过程中的反应机理,结合生产实际,通过采取优化配料方式及操作方法精细化等工艺措施,逐步提高沸腾焙烧锌精矿铜含量,取得了较好的效果,为企业创造了良好效益。     

Reduction of iron ore fines by coal fines in a packed bed and fluidized bed apparatus—A comparative study

Reduction of iron ore fines by coal fines in packed and fluidized beds has been studied. The investigation includes study of the kinetic aspects of reduction, carbon and sulfur content of the direct reduced iron (DRI) produced, and metallography of the products. For both processes, the kinetic data fit the first-order reaction model. Reduction in a fluidized bed is much faster than in a packed bed system. In both cases, DRI contains a substantial amount of free carbon at the initial stages of reduction. At the later stages of reduction, the carbon present in the DRI is mainly in the combined state. For identical temperatures and particle sizes, reaction in fluidized bed is much faster compared to that in a packed bed. At any particular degree of reduction, sulfur content in DRI samples produced by fluidized bed reduction is always more than that of DRI samples produced by packed bed reduction. Scanning electron microscopy (SEM) micrographs reveal that metallic whiskers formed during reduction in packed beds only. These whiskers become more prominent at higher temperatures and longer times.     

氢气还原1～3mm铁矿粉的动力学研究

在自制的kg级高温流化床中研究了氢气还原1～3 mm矿粉的动力学试验。随着时间的增加,气体利用率下降,表明还原前期反应速度快,后期反应慢;温度越高,气体利用率越高,但随着还原时间的增加,差距在逐步缩小;对于750℃,前20 min的气体利用率为9%,金属化率达到84%,说明氢气还原矿粉反应是非常迅速的。随着气速的增加,金属化率在增加,并且几乎成线性关系,因此使用氢气作为还原剂,可以允许更高的气速,从而提高设备的生产效率。随着料高的增加,金属化率不断下降,然而气体利用率却在不断升高。使用氢气作为还原剂,可以将还原温度降低到700～750℃,避免流化床过程中的粘结难题;试验中氢气还原1～3 mm铁矿粉时的表观活化能为58.4kJ/mol。     

Comprehensive Utilization of Complex Titania Ore

 To fully utilize Panzhihua titanium resources, a new process was proposed. In the process, Panzhihua ilmenite concentrate was first reduced in a rotary hearth furnace (RHF) to produce a titanium rich material and iron. The titanium rich material was then used in a new chlorination process to produce TiCl4. The comparison of different groups of experimental results or calculation results showed that the utilization ratio of material was improved by using the titanium rich material after pretreatment other than low level titanic ilmenite directly and the combined fluidized beds (FTF) were more likely to reduce bed height and reaction time than the single fluidized beds (Single F or Single T) under the condition of the same chlorination conversion ratio. Finally, the influence of reduction temperature and the anti agglomeration capacity of the combined fluidized bed was analyzed.     

Treatment of Landfill Leachate by a Combined Anaerobic Fluidized Bed and Zeolite Column System

The use of a combined anaerobic fluidized bed and zeolite fixed bed system in sanitary landfill leachate treatment was investigated. Anaerobic treatability studies were successfully performed in the anaerobic fluidized bed reactor. The chemical oxygen demand (COD) removal was attained up to 90% with increasing organic loading rates as high as 18?g?COD/L?day after 80?days of operation. Good biogas production yield (Ygas) of 0.53?L biogas per gram removed COD with methane (CH4) content of 75% was obtained. The attached biomass concentration increased along the column height from bottom to top, and its mean value was found 6,065?mg/L after 100?days of operation. The anaerobically treated landfill leachate was further treated by a zeolite fixed bed reactor. While excellent ammonia removal (>90%) was obtained with the untreated zeolite, the regenerated zeolites showed higher performance. Consequently, this combined anaerobic and adsorption system is an effective tool to remove high COD and high ammonia in landfill leachate.     

微型流化床内CO还原铁矿粉动力学试验

 采用微型流化床-过程质谱反应分析仪进行了铁矿粉的CO还原动力学研究。结果表明：微型流化床可抑制外扩散作用,利用等温方法算出的铁矿粉还原反应的活化能为2628kJ/mol,指前因子003946s-1,证明该铁矿粉还原符合气体内扩散控制机制模型,并且采用等温动力学方法可实现反应速率常数与模型函数的分离,极大地简化了计算过程,增加了动力学参数的准确性,为铁矿粉还原动力学的研究提供了一种简单可靠的测试方法。     

流化床反应器制备太阳能级颗粒多晶硅技术研究

采用流化床反应技术,以H2还原SiHCl3的方法制备太阳能级多晶硅。在直径50 mm的流化床反应器中,加入多晶硅颗粒作为初始晶种,通入SiHCl3和H2气体使颗粒处于流态化状态;高温下,反应生成的多晶硅在晶种表面沉积令颗粒逐渐长大而获得颗粒多晶硅。实验考察了流化床反应状态下的硅还原率和硅沉积速率及其影响因素,分别在950～1100℃,H2/SiHCl3摩尔配比为15,20,30及晶种粒径为350,550μm的条件范围内进行实验。当加入晶种粒径为550μm时,在1100℃条件下,H2/SiHCl3摩尔配比从15%增加到30%,硅还原率从14.2%提高到21.6%;当H2/SiHCl3摩尔配比为20时,温度从950℃提高到1100℃,硅还原率从14.9%提高到19.4%。在1100℃,H2/Si-HCl3摩尔配比为30的条件下,当加入晶种粒径为350μm时,测得硅还原率为25.7%,硅沉积速率为21.3 g.h-1;而晶种粒径为550μm时,硅还原率为22.9%,硅沉积速率为18.0 g.h-1。实验结果表明:提高H2/SiHCl3摩尔配比、提高温度和减少晶种粒径均可显著提高硅还原率和沉积速率,适宜的工艺条件为1050～1100℃,H2/SiHCl3(摩尔比)20～30;晶种颗粒粒径和流化床气流速度是流化床反应过程主要的动力学因素。在西门子法中应用流化床技术将能显著提高硅的还原率和沉积速率,是制备太阳能级多晶硅的可行技术。     

钛精矿颗粒在内构件流化床内停留时间特性的研究

在气固并流向上的有内构件流化床装置上,采用攀枝花钛精矿,研究了表观气速、加料速率、颗粒粒径以及挡板间距等不同因素对攀枝花钛精矿颗粒在床内停留时间特性及压降的影响.试验结果表明:流化床中增设水平内部构件可消除节涌,破碎气泡,强化气固接触,抑制颗粒返混,可形成均匀稳定的流化状态,非常有利于气、固接触反应.     

Decreased gas consumption of a fluidized bed furnace

The feasibility of utilizing a closed circulatory system to generate gases for a fluidized bed furnace was investigated with the primary concentrations of both economizing on the raw materials used for producing furnace atmospheres and decreasing the air pollution caused by exhaust gases. Air humidified with water vapor was first introduced into a charcoal furnace for causing a reaction with hot charcoal to form a carburizing atmosphere. This atmosphere was then introduced into a fluidized bed furnace to carburize steels. The exhaust gases from the fluidized bed furnace were recycled by repassing them through the hot charcoal layer in the charcoal furnace with a gas pump. The charcoal furnace and the fluidized bed furnace formed a closed circulatory system during the carburization of steels. Experiments were performed with various parameters of this system, including content of water vapor in the humid air, temperature of the charcoal, rate of recirculation of the atmosphere,etc. The effect of each parameter on the carburizing behavior in the fluidized bed furnace was investigated on the basis of the rate of carburization and the carbon potential of the atmosphere. The feasibility of applying this system to a fluidized bed furnace was assessed from the aspects of the fluidization of A1₂O₃ powder, the result of carburizing steel, and the rate of consumption of charcoal. The closed system employed in generating atmosphere was demonstrated by the experimental results to have enabled the fluidized bed furnace to operate normally and to have significantly decreased both the consumption rate of charcoal and the environmental pollution.     

Kinetics of Iron Chlorination of Roasted Illmenite Ore,Fe2TiO5 in a Fluidized-Bed Reactor

The preferential chlorination reaction of iron constituents in roasted ilmenite ore was studied in an experimental fluidized bed reactor. The influence of the roasting temperature on the selectivity of chlorination reactions was also examined. It was found that preferential iron chlorination is dependent on roasted product morphology. Effects of chemical and process variables in the fluidized bed reactor, such as chlorination temperature, chlorine gas partial pressure, gas-solid contact time and the quantity of coke added, were investigated in order to study the kinetics of the preferential chlorination reaction. A modified bubble assemblage model was applied to analyze behavior of gases and solids in the reactor. The chlorination reaction rate constant was found to be a function of temperature and coke quantity present.