车底式炉在石墨电极二次焙烧中的应用北大核心

在传统的石墨电极生产过程中,一般一次焙烧采用的设备为带盖式环式焙烧炉,再次焙烧采用隧道窑。随着国际技术交流的不断增加,一种既能用于一次焙烧又能用于再次焙烧的设备在国内炭素行业越来越多地被使用,根据其结构形式,将其称为车底式焙烧炉。本文主要就车底式炉在石墨电极二次焙烧中的应用作扼要论述。     

焙烧品质量缺陷问题的探讨

长期以来,对焙烧半成品的质量评价仅限于几种比较简单的理化性能检测,而对焙烧半成品内在质量的好坏,一直没有引起足够的重视,也缺乏必要的检测手段。但从近期我厂生产的几批UHP电极的质量情况看,有一定数量的成品存在内部组织不良或电极端头部分出现空洞等问题,影响电极的整体质量。最近的几次跟踪试验表明,焙烧工序存在一定的问题。因此,有必要对这些问题进行认真的探讨,并寻找解决问题的办法,以不断提高我厂产品的质量。     

车底式炉在石墨电极二次焙烧中的应用

在传统的石墨电极生产过程中,一般一次焙烧采用的设备为带盖式环式焙烧炉,再次焙烧采用隧道窑。随着国际技术交流的不断增加,一种既能用于一次焙烧又能用于再次焙烧的设备在国内炭素行业越来越多地被使用,根据其结构形式,将其称为车底式焙烧炉。本文主要就车底式炉在石墨电极二次焙烧中的应用作扼要论述。1车底式炉1.1概述车底式炉是多个单体设备联合使用的,每一台     

优化生阳极生产工艺改进焙烧阳极质量

预焙阳极生产是一个连续的、稳定的过程[l].焙烧阳极质量取决于生阳极质量和焙烧参数[2].目前,某铝厂焙烧炉状况良好,在生阳极焙烧过程中,主要参数包括最终焙烧温度、保温时间和加热曲线,因此,本次研究不再把焙烧温度视为可能影响焙烧阳极质量的可变因素.稳定、较高的生阳极表观密度和均质结构是提高焙烧阳极质量的关键,影响因素包括:煅后石油焦质量、生阳极配方(细粉指数、含量和沥青含量)和生阳极工艺参数[3].因此,我们把提高焙烧阳极质量的重点放在对上述因素的优化.     

进一步提高石墨电极机械加工质量的几点建议

对近年来在石墨电极机械加工中出现的电极孔锥螺纹长度、端部螺纹打半扣长度、螺纹加工梳刀、电极锥螺纹齿形测量,组合机床的维修,锥螺纹联接旋合度的设定等问题,提出几点参考性建议。     

填充料粒度对石墨电极焙烧效果的影响研究

通过对填充料粒度的影响所造成的石墨电极理化参数的变化进行统计归纳,认为通过合理调节填充料粒度配比,能够有效改善石墨电极焙烧品的理化参数,提高焙烧品尤其是接头产品的合格率。     

改善水泥使用性能的生产实践

夏季商品混凝土搅拌站客户反映,使用P·O42.5水泥生产的混凝土塌损大、凝结时间偏短,影响运输较远距离工地混凝土的泵送和施工。经分析认为主要原因是出厂水泥温度偏高和凝结时间偏短。根据工厂实际情况,经试验和试生产,找到既有效又增加成本不多的方法,实施生产,效果良好。     

The gas permeability of extruded graphite

The gas permeability of extruded graphite is extremely sensitive to the direction in which gas flow is measured. The technique of permeability measurement has been used to study the variation of pore structure of an extruded graphite and the data showed that a distinct directional pore pattern is present in this material. The factors which affect the pore structure of extruded graphites are discussed.     

Ways of improving the quality of fine-grained isotropic graphite in large objects

The main stages are considered in the development of equipment and technology for preparing large objects of hydrostatic compaction made of fine-grained isotropic graphite. The main organizations and workers whose efforts in Russia were the first to prepare this new form of carbon material are indicated. Some technical solutions are provided that make it possible to overcome difficulties in preparing high quality material of this class, and structural layouts for a hydrostat and its individual assemblies are presented. __________ Translated from Novye Ogneupory, No. 2, pp. 26–30, February 2008.     

我厂提高熟料强度的生产实践

我厂拥有一条2 500 t/d新型干法熟料生产线,与同行业先进水平相比熟料强度偏低,造成水泥料耗高、生产成本上升、质量风险高等一系列问题。分析原因,采取了优化配料,严控生料细度,提高入窑煤粉质量,优化篦冷机冷却风机等措施。结果表明：熟料强度得到提高且更加稳定,在保证水泥强度不降低前提下,各品种水泥中熟料掺量明显下降。同时水泥磨台时产量小幅度提升,水泥粉磨电耗明显下降。同时,水泥磨产量提高2.79 t/h,水泥粉磨电耗降低1.64 kWh/t。每年可降低水泥生产成本350万元以上,经济效益客观。     

Rate effect on lithium-ion graphite electrode performance

The electrochemical performance of lithium-ion graphite electrodes with particle diameter in the range of 6–44 µm was evaluated at different discharge (intercalation)/charge (deintercalation) rates (C to C/60). The electrode capacity depends on both the average particle size and rate. With a simple rate programme, the electrode performance is dependent on the cycling rate. The capacity of small graphite particles (6 µm) at C/2 rate was 80% of that achieved at C/24 rate (372 mAh g^–1). The capacity of large graphite particles (44 µm) obtained at fast rates (C/2) was only 25% of that obtained under near-equilibrium conditions (C/24). The electrode capacity, however, is nearly independent of the charge rate when the electrode is fully intercalated using a modified rate programme containing a constant-voltage hold at 0.005 V (vs Li⁺/Li) for several hours. The electrochemical behaviour is related to the physicochemical properties of the graphite particles.     

提高预焙阳极质量的一些措施

从焙烧工艺和焙烧炉燃烧设备两个方面介绍了中铝青海分公司炭素厂二期焙烧车间投产初期提高预焙阳极质量的一些措施,对焙烧车间提高预焙阳极质量有一定借鉴意义.     

Electrooxidation of methanol on NiMn alloy modified graphite electrode

Nickel and nickel-manganese alloy modified graphite electrodes (G/Ni and G/NiMn) prepared by galvanostatic deposition were examined for their redox process and electrocatalytic activities towards the oxidation of methanol in alkaline solutions. The methods of cyclic voltammetery (CV), chronoamperometry (CA) and impedance spectroscopy (EIS) were employed. In CV studies, in the presence of methanol NiMn alloy modified electrode shows a significantly higher response for methanol oxidation. The peak current of the oxidation of nickel hydroxide increase is followed by a decrease in the corresponding cathodic current in presence of methanol. The anodic peak currents show linear dependency upon the square root of scan rate. This behavior is the characteristic of a diffusion controlled process. Under the CA regime the reaction followed a Cottrellian behavior and the diffusion coefficient of methanol was found to be 4 × 10⁻⁶ cm² s⁻¹. A mechanism based on the electro-chemical generation of Ni³⁺ active sites and their subsequent consumptions by methanol have been discussed and the corresponding rate law under the control of charge transfer has been developed and kinetic parameters have been derived. The charge transfer resistance accessible both theoretically and through the EIS have been used as criteria for derivation of the rate constant.     

徐州铁矿集团选厂扩产提质技术改造生产实践

0 引言 徐州铁矿集团选矿厂为上世纪70年代建成的老选厂,工艺流程依据原老矿体的矿石性质而设计.随着原有矿体的资源枯竭,新矿体的开发,原选厂的工艺流程已不适应新矿体的矿石选别,为此对选厂流程进行了改造.