采用物料氧化镁还原率、XRD、SEM等手段与方法研究真空条件下煅白碳热还原温度、物料配比、碳热还原保温时间等对碳热还原煅白制取金属镁工艺的影响。结果表明:在30~100 Pa时,碳热还原温度高于1 623K后,氧化镁的还原率明显增加,有利于碳热还原反应的进行。随着焦煤还原剂与氧化镁摩尔比的增大以及碳热还原时间的延长,碳热还原反应反应速率加大,还原率提高,当碳热还原温度为1 623 K、还原时间为4 h、配碳比为1.6时,氧化镁还原率超过99%。因此,选择适当的焦煤还原剂与氧化镁摩尔比值以及碳热还原时间,在温度高于1 623 K条件下,将有利于碳热还原法炼镁过程的顺利进行与氧化镁还原率的提高。

The temperature of calcined dolomite carbothermic reduction, molar ratio and carbothermic reaction time by calcined dolomite carbothermic reduction in vacuum were investigated by MgO reduction rate, XRD and SEM. The results show that the reduction rate of MgO clearly increases when temperature is higher than 1 623 K at 30?100 Pa, which is beneficial to MgO carbothermic reaction. The carbothermal reduction reaction rate increases with the increase of the molar ratio of coking coal reductant and magnesium oxide and carbon thermal reduction time at the carbon thermal reduction temperature of 1 623 K, the reduction time of 4 h and carbon ratio of 1.6, the magnesium oxide reduction rate is over 99%. Therefore, selecting the appropriate molar ratio of coking coal reductant and magnesium oxide and carbon thermal reduction time is beneficial to carbothermal reduction process for magnesium smelting going smoothly and magnesium oxide reduction rate increasing at the temperature higher than 1 623

本文旨在研究不同温度下氢气对褐铁矿还原度和还原速率的影响,并以此为基础分析动力学相关问题.通过热重分析深入了解褐铁矿失水状况.使用粒度为8~12 mm褐铁矿焙烧后,分别在750~950℃五个不同温度下使用4 L·min-1 H2进行还原,并分析还原率和还原速率随时间的变化关系.研究发现：随着反应进行,试样还原率逐渐增大,五条还原率曲线在t>28 min后与还原温度排序一致.通过动力学研究计算得反应表观活化能E=15.323 kJ·mol-1,从而确定扩散为还原反应的限制环节.

This article presents experimental studies on the effects of H2 on the reduction degree and rate of limonite at different temperatures and kinetic analysis during the hydrogen reduction. The water loss of limonite was investigated by thermal gravimetric analysis. Limonite of 8 to 12 mm in granularity was reduced with 4 L·min-1 H2 at five temperatures of 750 to 950℃. As the reduction reaction proceeded, the reduction degree increased, and the sequence of 5 reduction degree curves was consistent with that of reaction temperature when t>28 min. The apparent activation energy was kinetically calculated to be 15. 323 kJ·mol-1 , so diffusion is the re-strictive step of the reduction reaction.

通过对三种不同机理的锡渣还原试剂还原出来焊料的还原率、上锡性、润湿性、组成成分及熔点的测试与分析,探索锡渣还原试剂的使用对焊锡品质的影响。结果表明:三种还原率均超出80%;还原剂可增强焊料的上锡性;还原剂对焊料的润湿性有影响;还原前后焊锡的成分变化不明显,不影响焊锡的熔点。通过对比试验,评估锡渣还原试剂在焊料焊接生产中的适用性,并给出未来锡渣还原剂仍需改进的方向。

The effects of solder quality using three reductants of solder splash ware explored by test analysis of solders reduction rate, solderability, wettability, composition and melting point. The results indicated that the reduction rates of three reductants exceeded 80%. Solders reductant could improve solderability, but the effect was a little more than raw solder bar. Solder wettability was effected by reductants. Solder compositional variations ware unconspicuous before and after reduction, and solder melting points ware constant. Solder reductant applicability is estimated in the production process and the orientation of solder reductant improvements in the future are given by contrast tests.

以纯磷酸钙、氧化钙、二氧化硅、氧化铝和氧化镁为原料配矿，固体石墨为还原剂，进行磷矿还原反应。熔渣中五氧化二磷含量用磷钼酸喹啉质量法分析，考查了不同反应时间、不同温度、不同酸度对还原率的影响．结果表明：反应温度越高、反应时间越长，还原率越高；配矿中酸度 mk ＝1．15时的还原率较 mk＝0．85、0．75高，而 mk＝0．75时的还原率增幅最大．对固体碳还原磷酸盐的反应进行了动力学拟合，得到静置条件下固体碳还原配矿中磷酸盐的表观反应速率常数的表达式，证实了在高温反应条件下，磷矿还原反应为扩散控制过程．

The phosphate reduction reaction was carried out with ore slag and solid graphite as reactant. The prepared slag is a mixture of pure calcium phosphate, calcium oxide, silica, magnesia and alumina. The reaction time, temperature and slag acidity were changed during the reactions. The reduction rate was obtained by analyzing phosphorous pentoxide content in slag with Quinoline phosphomolybdate gravimetric method. The results show that the reduction rate increases simultaneously with the increase of reaction temperature and the reaction time;w hen the acidity mk is 1. 15, the reduction rate is higher than that as mk is 0. 85 and 0. 75 ;the highest increase in the reduction percentage is obtained w hen mk is 0. 75. T he kinetic experiments of the reduction process w ere carried out in static conditions, and the apparent reaction rate equation was obtained, which confirms that the rate control step in reduction process of phosphate with solid carbon at a high temperature is the d

采用纯的氧化铁进行直接还原的实验研究，利用H2作为还原气体在高温管式炉中进行焙烧还原.结果表明，随着反应时间的增加，氧化铁块还原率相应的增大.反应温度的不同，氧化铁块还原速率及电导率也相应的不同.600~900℃下经过一定时间的氢还原，还原产物的还原速率随温度的增加而增加，均可达到95%以上.通过交流阻抗法对还原产物的电导率的测试，得到了还原产物的电导率随时间和还原度的变化曲线.随着温度及时间的不同，电导率也相应变化，电导率的不同，可间接反映还原过程中产生了导电性不同的物质.

Direct reduction experiments of pure iron oxide has been investigated using hydrogen as reducing gas in high temperature tube furnace. The results show that with adding reaction time , iron oxide reductive ratio increases accordingly. The reduction ratio of iron oxide and conductivity of reductive product are different accordingly with different reduction temperatures. After hydrogen reduction at the temperature from 600 ℃ to 900 ℃, reduction ratio of reduction product, reaching above 95 %, increases with the increasing of temperature. The curve of reduction product conductivity changing with time and reduction degree is obtained by testing reduction product’s conductivity adopting ac impedance method. The conductivity of product varies accordingly to the different reduction temperature and time. The variation of conductivity indirectly reflects that products with different conductivity have been produced.