钼精矿焙砂压力成型的工艺过程研究

着重研究了适合于钼精矿焙砂压力成型的原料粒度组成，提出了相应的破碎流程。此外，还就预先碾压对于成型过程的影响进行了研究，并得到了肯定的结论。采用这一工艺过程进行连续成型试验，成球系数达到８６．５％。     

Desilication from illite by thermochemical activation

Illite occurs widely in bauxite ores and results in low alumina grade of the ores. Differential thermal analysis (DTA), thermal gravimetric analysis (TGA) and X-ray diffraction analysis (XRD) show the OH groups split off from the structural framework of illite between 500 ℃ and 700 ℃. With the increase in temperature up to about 1 100 ℃, the layer structure of illite breaks up and Si in the layers is transformed into the amorphous state. Meanwhile, mullite comes out at 1 100 ℃. Quartz occurring in illite keeps unchanged in structure in the range of 500 -1 200 ℃. A desilication process from illite by thermochemical activation followed by alkali leaching is therefore developed on the basis of the behavior that amorphous silica is alkali soluble. The investigation finds that the optimum parameters for desilication are activation temperature of 1 100 - 1 150 ℃, activation time of 90 - 120 min, leaching temperature of 95 - 110 ℃, leaching time of 90 - 120 min and concentration of caustic soda (Na2Ok) 120 - 150 g/L. An overall desilication about 45% is attained under these conditions. XRD analysis confirms that the active amorphous SiO2 has been dissolved in the alkali solution and removed from the samples, while quartz and mullite have not. The investigation also shows that the formation of mullite during activation and formation of sodium hydroalu minosilicates (Na96 Al96 Si96 O384 and 0.95Na2 O · Al2 O3 · 3.25SiO2 · 4.79 H2 O) during leaching lead to the relatively low desilication of illite.     

高铁三水铝石型铝土矿的烧结特性

以Al2O3含量为26.35%,总Fe含量为31.22%,铝硅比为3.17的某高铁三水铝石型铝土矿为原料,研究了碱度、焦粉用量、混合料水分等对烧结矿质量指标的影响。结果表明:烧结矿碱度增加时,其转鼓强度和成品率下降,烧结矿自粉化程度加重;焦粉用量增加时,烧结矿转鼓强度和成品率提高;当混合料水分为9.0%、焦粉用量为8.0%、烧结矿碱度为4时,烧结矿转鼓强度为69.1%,成品率为81.2%,垂直烧结速度为30 mm/min,利用系数为1.2 t/(h.m2);烧结矿碱度为4时,样品存放2天粉化率为5%,烧结矿平均粒度由22.2 mm减小到21.9 mm,延长存放时间,烧结矿自粉化率增大,平均粒度显著减小。该烧结矿的冶金性能能基本满足高炉冶炼的要求。     

Direct reduction of carburized pre-reduced pellets by microwave heating简

A new iron-making process using carburized pre-reduced iron ore pellets and microwave heating is investigated. The pre-reduced pellets, with a porous structure, and fine particles are carburized homogeneously at 400-650 ℃ in a CO atmosphere. The carburized carbon not only acts reaction as a reduction agent, but also absorbs microwave in the reduction process. Hence, the carburized pre-reduced pellets can be rapidly reduced by microwave heating. There are three procedures involved in the process, namely, gas-based pre-reduction, low-temperatttre carburization and deep reduction by microwave heating. Carburized pre-reduced iron ore pellets show a rapid temperature rise that is twice as fast as the results for pre-reduced pellets in the laboratory. This not only improves the efficiency of the microwave heating, but also accelerates the reduction of iron oxides. The temperature of the pre-reduced pellets rises to 1050 ℃ in 45 min when the carburization rate is 2.02%, and the metallization rate and compressive strength reach 94.24% and 1725 N/pellet, respectively.     

高岭石脱水反应的非等温热重法研究

在系统分析非等温固相反应特点的基础上,建立了非等温脱水反应速率方程.采用非等温热重法、通过计算机辅助计算,对高岭石脱水反应动力学规律进行了研究.结果表明:由于高岭石晶体结构中内、外羟基脱除的顺序不同,其脱水反应机制在反应分数(α)为0.7左右时发生改变.在反应前期(0＜α＜0.7)时,脱水反应遵循二维扩散控制规律,脱水反应表观活化能为159.682 kJ/mol、表观频率因子为1.007×10 10/min.     

白云石和蛇纹石对烧结矿质量及显微结构的影响

白云石和蛇纹石对烧结矿质量及显微结构影响的研究结果表明:配加白云石提高烧结矿的MgO含量,烧结矿转鼓强度降低,而配加蛇纹石提高烧结矿的MgO含量时,转鼓强度提高.配加白云石后,烧结矿矿物组成主要为铁酸钙与骸晶状赤铁矿,骸晶状赤铁矿周围有大量以玻璃质物相存在的硅酸盐矿物,且有大量微细裂纹;烧结矿孔隙率大,气孔为大孔薄壁结构,所以烧结矿强度低.配加蛇纹石后,烧结矿矿物组成主要为磁铁矿和铁酸钙,钙铁橄榄石矿物增多变大,气孔为中孔厚壁结构,所以烧结矿的质量得以改善.     

山东某金矿金的工艺矿物学及其浸出特性

山东某金矿金的工艺矿物学及其浸出特性中南工业大学黄柱成，姜涛山东省黄金局刘成义山东乳山金矿是一个大型石英脉型金矿床。矿石中除富含有金、银外，还含有铜、硫、碲等有价元素。为了查明下部矿体矿石的性质，有效地回收矿石中的金银等有价元素，本文对该金矿深部矿体...     

从湿法炼锌渣中回收镓和锗的研究（上）——浸锌渣的还原分选

湿法炼锌浸出渣中含有大量的镓、锗，具有极高的综合同收价值。利用镓、锗所具有的亲铁特性，开发了浸锌渣还原分选富集镓、锗的新工艺。该工艺通过强化浸锌渣的还原过程，使镓、锗定向富集于金属铁中(金属铁是镓、锗的主要载体矿物相)，进而采用磁选的方法从焙烧渣中分离富集镓、锗。研究表明，在温度为1100℃、恒温还原时间为150min的条件下处理含Ga527g／t、Ge305g／t的某厂湿法炼锌浸出渣，可得到镓品位为2164g／t回收率为92．40％，锗品位为1600g／t回收率为99.03％的铁粉。     

冷固结球团直接还原采用强力混合机的研究

本文进行了冷固球团直接还原工艺采用强力混合机的研究。结果表明：采用强力混合机进行添加复合有机粘结剂的混合料制备，在工艺技术上是可行的，其生球、干球质量均可满足直接还原工艺的要求。     

热烧结矿竖式冷却过程传热特性

 与传统环冷相比，烧结竖冷拥有漏风率低、换热效率高的优势。为此利用竖冷试验装置，在某烧结厂取热风与热烧结矿研究了竖式冷却过程气固对流换热特性。研究表明，烧结矿竖式冷却过程中影响传热特性的主要因素为冷却风的流量及温度。烧结矿和冷却风对流换热系数随着烧结矿温度的升高而增大，且随着冷却风流量的增大以及冷却风温度的降低，对流换热系数也随之增大。基于白金汉定理，结合试验数据拟合得出了描述烧结矿与冷却风传热特性的准数关联式，其模拟性较好且平均相对误差为7.25%。