混联法生产氧化铝的熟料烧结问题探讨

采用贵州低品位铝土矿和溶出拜耳赤泥、碱、石灰配制的混合料烧结,在A/S=2.84±、[N]/[A]+[F]=0.97±、[C]/[S]=2.11±、t℃=1275±时,可以获得较好的效果。氧化铝标准溶出率η(?)标=94.64%,氧化铝工业溶出率=92.68%。     

真空碳热还原酸浸含钛高炉渣制备TiC分析

含钛高炉渣中含有20%~30%的TiO_2,是一种附加值较高的二次资源,但在综合利用过程中存在氧化物还原难度大,硅钛难分离,二次污染严重等问题。基于热力学理论基础,采用真空碳热还原联合酸浸工艺处理含钛高炉渣制备TiC。结果表明:真空有助于钛氧化物彻底还原,可实现渣中硅钛彻底分离,减少酸耗量,降低二次污染。真空碳热还原联合酸浸工艺处理含钛高炉渣(TiO_2含量23%左右)制备TiC的最佳条件为:炉渣粒度200目,还原温度1 673K,渣碳质量比100∶38。     

Reductive leaching of low-grade manganese ore with pre-processed cornstalk

Cornstalk is usually directly used as a reductant in reductive leaching manganese. However, low utilization of cornstalk makes low manganese dissolution ratio. In the research, pretreatment for cornstalk was proposed to improve manganese dissolution ratio. Cornstalk was preprocessed by a heated sulfuric acid solution (1.2 M of sulfuric acid concentration) for 10 min at 80°C. Thereafter, both the pretreated solu-tion and the residue were used as a reductant for manganese leaching. This method not only exhibited superior activity for hydrolyzing corn-stalk but also enhanced manganese dissolution. These effects were attributed to an increase in the amount of reductive sugars resulting from lignin hydrolysis. Through acid pretreatment for cornstalk, the manganese dissolution ratio was improved from 50.14%to 83.46%. The pre-sent work demonstrates for the first time the effective acid pretreatment of cornstalk to provide a cost-effective reductant for manganese leaching.     

交流电机导电紫铜环焊接缺陷研究

对交流电机导电紫铜环焊接接头的焊趾、焊根的金相组织进行分析,结果表明其内部不存在裂纹、未焊透等缺陷.然后分别对熔合区金相组织进行分析、再对焊缝金属进行微观组织分析时发现裂纹,经研究确定该裂纹均为液化裂纹.     

钢渣滤料对磷的吸附动力学和热力学

以钢渣为主要原料,添加少量粘土和造孔剂制备钢渣滤料。通过批次吸附实验,研究了钢渣滤料对废水中磷的吸附特性。结果表明,不同温度条件下钢渣滤料对磷的吸附过程均符合准二级反应动力学方程,反应的活化能〉40kJ／mol。等温吸附过程符合Langmuir方程,在20℃、30℃和40℃时的最大吸附量分别为1．166、1．826和2．422mg／g。热力学参数△G^0、△H^0和△S^0表明,该过程是自发、吸热、熵增型反应,且磷的吸附以化学吸附为主。     

常压下硫酸体系中钴冰铜的浸出

对云南某镍矿镍转炉渣经碳还原、黄铁矿硫化所得的钴冰铜进行工艺矿物学及其在常压条件下硫酸浸出的研究。考察温度、硫酸起始浓度、浸出时间及液固比等因素对钴、镍浸出率的影响，以及在两段逆流浸出流程中镍、钴的浸出率。实验结果表明：硫酸浓度以及浸出温度对钴、镍浸出率影响较大，当硫酸初始浓度为6mol／L，浸出温度为100℃，浸出时间为6h，液固比为5时，钴冰铜中钴、镍的浸出率分别达到95．37％和96．73％；在两段逆流浸出实验中，钴、镍的浸出率分别达到99．62％和99．58％，渣中铜的品位达到34．42％，回收率达到96．42％。     

微生物催化还原浸出深海锰结核中有价金属

在常温、酸性、厌氧环境下,按一定的比例添加微生物培养基和供电子体,采用J13菌连续高密度培养、矿浆预浸、微生物固定和强化传质的手段,提高微生物浸出结核中有价金属的速率,浸出时间为3 d,可直接浸出结核中的铜、钴、镍和锰.浸出率:钴95.2%,镍97.5%,锰95.8%,铜81.2%;按此方法进行了陆地软锰矿和硬锰矿的浸出试验,浸出时间9 d,锰矿中的锰浸出率较高.根据以上试验结果提出了微生物催化两矿偶合还原浸出氧化锰矿中有价金属的方法,并初步探索了浸出机理.     

Flexible micro-supercapacitors fabricated from MnO2 nanosheet/graphene composites with black phosphorus additive

Supercapacitors are widely used for powering flexible/wearable electronics owing to their excellent charge storage capabilities. In this study, MnO₂ nanosheets were grown on the surface of graphene using a simple water bath method to prepare graphene/MnO₂ composites for fabricating supercapacitors. In addition, two-dimensional black phosphorus was introduced as an additive into the electronic ink based on the as-prepared graphene/MnO₂ composites. The characterization and electrochemical analyses results showed that adding black phosphorus considerably improved the capacitive performance of the material, yielding a high specific capacitance of 241.5 ?F ?g^-1 at 0.1 ?A ?g^-1 and an impressive rate capability improvement from 52.5% to 80.3%. Then the micro-supercapacitor having an area-specific capacitance of 20.15 ?mF ?cm^-2 at a scanning rate of 2 ?mV ?s^-1 was utilized to demonstrate the practical applicability of this material. To further evaluate the practical applicability of this micro-supercapacitor, the micro-supercapacitor was integrated with a flexible thin-film pressure sensor on paper and cloth through screen printing.     

富硅钒尾矿热活化及改性制备绿色环保“一体化”地聚合物

本研究的目的是通过热活化和改性的方式,将富硅钒尾矿制备成地聚合物前驱体。在热活化阶段,钒尾矿和氢氧化钠均匀混合后在高温下煅烧。掺入偏高岭土来调节热活化后钒尾矿的硅铝比例,并得到地聚合物前驱体。结合TG-DSC,SEM,XRD以及活化钒尾矿浸出试验结果发现,在热活化过程中,钒尾矿首先被氢氧化钠腐蚀,然后在颗粒表面形成硅酸钠。热活化后的钒尾矿在加水后,钒尾矿颗粒表面的硅酸钠层溶解,释放出硅组分并形成碱性的溶液环境。偏高岭土能够在碱性环境中溶解释放出铝组分,并与先前释放的硅组分发生地质聚合反应。残余未反应的颗粒通过地质聚合过程中产生的凝胶连接,从而紧密的粘结在一起,随后养护硬化成具有优异机械性能的地聚合物产品。本研究能够提高了地聚合物技术在大规模工业现场应用的可行性,能够促进钒尾矿及其他富硅的固体废物的综合利用。     

酸梅饮料提取工艺研究

对酶梅饮料生产的提取工艺进行研究。发现其浸出过程符合三维平板扩散模型,得出８０℃／６ｈｒ每１０ｍｉｎ搅拌一次的浸取工艺条件。