镁热法制备高纯金属镝

对镁热法制备高纯金属镝进行了研究，结果表明：采要用高纯氯化剂氯化高纯（4N）氧化镝（Dy2O3）制取无水氯化镝（DyCl3），用镁还原无水氯化镝制得镁－镝合金，再经蒸馏制备金属镝的工艺，可以制得高纯镝，纯度可达99．99％。     

皮江法炼镁与真空碳热还原法炼镁生命周期评价比较研究

对皮江法炼镁工艺和真空碳热还原法炼镁工艺进行了生命周期评价研究。评价过程以1 t镁锭为功能单位,研究了包括原料开采、物料制备、物料耗损、能源生产、污染排放等过程的环境负荷以及能源消耗。在得出生命周期评价相关参数的基础上,对皮江法炼镁与真空碳热法炼镁在资源与能源消耗、气型污染物的排放和对环境的影响方面进行了比较,明确了上述两种不同工艺过程各自的环境负荷和能源消耗特点。通过比较,碳热法炼镁工艺较皮江法在资源节约、节能减排、环境保护及可持续发展方面有明显优势。     

提高镁热法生产海绵钛用镁还原剂质量的研究

采用SEM和EDS分析了镁热法生产海绵钛用镁还原剂中杂质的分布及成分,根据实际生产过程找到了杂质的来源,提出了杂质的控制措施。     

The Effect of Reduction Parameters on Iron Nugget Production From Composite Pellets

Composite pellets which contain a reducing agent and are produced only by cold bonding process are improved instead of traditionally hardened pellets by sintering. The new ironmaking technologies that are able to utilize these pellets have been developed from pilot plant to commercial scale. Iron nuggets which have a similar composition to pig iron can be produced by using composite pellets at high temperatures (1350–1400°C) and in a short reduction time (15–20 min) by smelting reduction process. In this study, the effect of reduction parameters and basicity of composite pellets on the reduction properties and product quality are investigated. Composite pellets containing magnetite concentrate with a reducing agent (coke) and a flux are processed at different temperature and at times by smelting reduction process. The increasing temperature and time has a positive effect on reduction and melting of the pellets. Excessive carbon prevents the metal droplets from coalescing. The iron nugget that is produced from the sample with the basicity (CaO/SiO₂) of 0.68 has the optimal physical and chemical properties. It is also determined that a decrease or increase of basicity has a negative effect on the properties of the iron nuggets.     

电热法生产铸造用共晶铝硅合金的能耗分析

介绍了电热法生产铸造用铝硅合金的工艺流程,同时对兑掺法和电热法生产铸造用铝硅合金的能耗进行了分析,结果表明：电热法生产共晶铝硅合金与兑掺法相比可节能5%以上,成本可降低700元以上。     

新型真空热还原法制镁工艺分析

通过对真空条件下A l-S i-Fe合金还原白云石煅白的热力学分析及实验研究,得到真空条件下还原反应的吉布斯自由能及反应临界温度,确定工艺可行性;所进行还原实验的结果表明:在还原温度1 443 K、还原时间2 h、真空度4 Pa、制团压力50 MPa条件下,可获得86.4%的镁收率,相比同等条件下硅热法镁还原率仅为73.9%。     

含碳球团还原熔分试验研究

以铁精粉、煤粉和石灰石为主要原料制成含碳球团,进行还原熔分试验,并对渣铁形貌和渣铁分离程度进行分析。结果表明含碳球团还原熔分试验的最优方案是:还原温度1 480℃,配煤量(按wC/wO计算)1.2,还原时间22 min,炉渣二元碱度R21.0。在最优试验方案下,得到的粒铁产品质量指标良好,渣铁分离效果最佳,渣中Fe O含量最低,铁收得率高达98.62%。     

Advanced Method for Recycling Red Mud by Carbothermal Solid-Phase Reduction Using Sodium Sulfite

Metallurgist - The paper presents the results of studying the iron grain growth mechanism during carbothermal solidphase reduction of red mud in the presence of sodium sulfate. It was shown that...     

高还原势气氛下球团矿还原行为的研究

炉顶煤气循环氧气高炉采用纯氧鼓风以及炉顶煤气循环利用工艺使得炉内煤气成分与传统高炉相比发生了改变,炉内的煤气成分主要以H2和CO为主.为了研究还原性气体H2和CO对球团矿还原行为的影响,分别用H2-N2、CO-N2、H2-CO混合气体在1173K下通过热重的方法进行试验.研究发现还原度随着混合气体中H2或CO比例的增加而增加,但是H2的还原能力明显比CO要强.在H2-CO混合气体中H2的加入有利于还原进行.用H2-CO混合气体还原得到的还原速率不能用H2-N2和CO-N2混合气体下得到的还原速率相加得到.微观结构观察发现,用H2进行还原时得到的铁结构较致密,而用CO还原时铁会破裂为许多小碎片.在用含一氧化碳的混合气体进行还原时,还原度曲线在还原后期由于碳沉积导致出现下降的趋势.还原气体中氢气的存在会加剧碳沉积现象,而氮气的存在会抑制这一现象.对还原后试样进行X射线衍射以及化学分析表明试样中的碳以碳化铁(Fe3C)和石墨形式存在.     

镁法海绵钛生产中高温烧结的分析与控制

论述了镁法海绵钛生产过程中高温烧结的形成及其影响因素,分析了减少高温烧结的控制措施。     

三氧化二铋碳热还原反应的动力学

由于铋元素密度较大,在工业硅碳热还原冶炼过程中容易沉淀,导致冶炼所得工业硅中杂质分布不均,质量下降,因此研究铋在碳热还原反应中的动力学行为,为工业硅冶炼中铋含量的控制提供理论指导具有重要意义。通过热重分析方法研究了不同碳质还原剂对铋氧化物（三氧化二铋）碳热还原的影响。结果表明,石油焦相较于石墨活性更高,石油焦作还原剂具有更好的还原性能。对不同温度下三氧化二铋还原熔炼产物进行了物相分析,其还原反应产物物相转变顺序为：Bi2O3→Bi2O2.5→Bi。通过热重分析法研究了不同升温速率下三氧化二铋碳热还原反应动力学,应用等转化率法、Kissinger法和?atava-?esták法进行动力学分析,得到三氧化二铋碳热还原反应平均表观活化能E0=142.41 kJ/mol,指前因子A0=2.96×109 s-1;反应机理属于相边界反应,对应的动力学方程微分形式为3(1—α)2/3。     

铌精矿微波碳热还原反应动力学

针对白云鄂博铌精矿利用工艺的成本高、过程复杂、能耗大的特点,引入微波场,考察温度对铌精矿还原的影响,并对其进行形貌及动力学分析。结果表明,微波场中铌精矿碳热还原反应机理属于三维扩散,动力学方程为y=1-(2/3)α-(1-α)2/3,表观活化能Ea=131.654 kJ/mol,微波加热相对于常规加热具有加快反应速率、降低反应活化能的效果。     

钛精矿碳热还原制备碳氮化钛的研究

以钛精矿和石墨为原料,在氮气气氛下通过碳热还原法制备出碳氮化钛(Ti CN)粉体。结合XRD、SEM、化学成分分析和TG-DSG综合热分析研究了配碳量及反应温度对钛精矿碳热还原进程的影响。研究结果表明,配碳量的增加影响逐级还原反应温度以及反应总失重,当配碳量达到23%时碳氮化钛产物中出现游离碳。钛精矿碳热还原过程中铁氧化物优先还原,钛氧化物经逐级还原形成Ti CN,还原顺序为Ti O2→Ti4O7→Ti3O5→Ti N→Ti(C,N,O)→Ti CN。得到的碳氮化钛粉体呈微米级不规则形状。     

Carbothermal Solid State Reduction of Stable Metal Oxides

The paper considers carbothermal solid state reduction of manganese, titanium and aluminium oxides in argon, helium and hydrogen. The difference in reduction in helium and argon was reflected by different diffusion coefficients of gaseous reactants and products, which are much higher in helium than in argon. When carbothermal reduction took place in hydrogen, it was involved in the reduction process by reducing oxides to suboxides and forming methane. Manganese and titanium oxides were reduced to carbide Mn₇C₃ and oxycarbide Ti(O_xC_1‐x) correspondingly, while products of alumina reduction included carbide Al₄C₃ and vapours of Al and Al₂O, which were re‐oxidised to Al₄O₄C outside the reactor and deposited in the lower temperature zone. Gas atmosphere had a profound effect on the extent and rate of reduction. This effect was different in reduction of different oxides. Reduction of manganese oxides was the fastest in hydrogen, and faster in helium than in argon. Reduction of titania in argon and helium proceeded with about the same rate and was much faster in hydrogen than in the inert atmospheres. The rate and extent of alumina reduction in hydrogen and helium were higher than in argon, although no significant difference was observed in alumina reduction in hydrogen and helium. This reflects differences in reduction mechanisms, which are discussed in the paper.     

碳热还原法制备LiFePO4/C锂电池正极材料的研究

以Fe2O3为铁源,NH4H2PO4为磷源,Li2CO3为锂源,蔗糖为碳添加剂,应用碳热还原一步烧结法制备了LiFePO4/C复合粉体材料,系统的研究了烧结温度、烧结时间和锂铁比对样品电化学性能的影响。研究结果表明,对电化学性能影响因素最大的是烧结温度、其次是锂铁比,最后是烧结时间。当烧结温度为700℃、锂铁比为1.00、烧结时间为12 h时样品所得的电化学性能最佳,它在0.1C,0.5C和1.0C倍率下的首次放电比容量分别为130.1,118.2和105.6 mAh.g-1,经20次循环后,不同倍率下样品的容量的保持率分别为99.8%,98.9%和97.5%。     

Carbothermal Reduction of Iron Ore Applying Microwave Energy

This paper presents the results of a study on carbothermal reduction of iron ore made under the microwave field in equipment specially developed for this purpose. The equipment allows the control of radiated and reflected microwave power, and therefore measures the microwave energy actually applied to the load in the reduction process. It also allows performing energy balances and determining the reaction rate with high levels of confidence by simultaneously measuring temperature and mass of the material upon reduction with high reproducibility. We used a microwave generator of 2.45 GHz with variable power up to 3000 W. Self‐reducing pellets under argon atmosphere, containing iron ore and petroleum coke, with 3.5 g of mass and 15 mm of diameter were declined. We obtained the kinetic curves of reduction of iron ore and of energy consumption to the process in the maximum electric field, in the maximum magnetic field and at different values of power/mass. The data allow analyzing how the microwave energy was actually consumed in the reduction of ore.     

新型竖置镁还原罐的设计

提出了外罐加内罐的竖置套罐结构。应用FLUENT软件对罐体及内部物料的传热过程进行模拟分析。结果表明,新型竖置还原罐的加热速率较传统还原罐快。经实际工程应用验证,还原罐的使用寿命延长到5个月以上,且实现了机械装出料,提高了球团料加热速率,缩短了还原周期。     

Experimental and Modeling Study on Reduction of Hematite Pellets by Hydrogen Gas

Metallurgical and Materials Transactions B - Gaseous reduction by hydrogen was performed for three types of hematite pellets, two from industry and one prepared in the laboratory. The reduction...