Investigation of the energy-size reduction and mineral liberation of raw coal in the Hardgrove mill

Raw coal was ground in a Hardgrove mill, and mineral liberation from coal was investigated by float-sink test and electron probe microanalyzer (EPMA). Based on EPMA, associated conditions of mineral were determined. Analyses of energy-size reduction show that energy efficiency decreases with time. For +0.074 mm progenies, yields of particles in ?1.5 g.cm^?3 decrease with the increase of size and time, and products in +1.8 g.cm^?3 show the opposite trend. EPMA of 0.25–0.125 mm, 1.5–1.8 g.cm^?3 products ground for 10 min indicates that only part of minerals are liberated. For ?0.074 mm products, the yield of particles in ?1.5 g.cm^?3 decreases by 23.36% in last several minutes, but ash content of +1.8 g.cm^?3 also decreases by 13.18%. Since breakage of raw coal in last 9 min does not reduce particle size obviously, and liberation degree cannot be improved dramatically, closed grinding of 10 min in Hardgrove mill is proper to balance the size reduction and mineral liberation.     

Enhancement of photoelectrochemical activity of Fe2O3 nanowires decorated with carbon quantum dots

Owing to its up-conversion photoluminescence, photo-induced electron transfer property, and excellent conductivity, carbon quantum dots (CQDs) have been established as effective sensitizers in combination with Fe₂O₃ nanowires for enhancing the catalytic activity of photoelectrochemical water oxidation. In comparison to pristine Fe₂O₃ nanowires, Fe₂O₃ nanowires decorated with CQDs demonstrate 27 orders of magnitude increase in photocurrent density at 0.23 V vs. Ag/AgCl. The mechanism of enhanced photoelectrochemical activity of CQDs/Fe₂O₃ composite was also investigated. Thereby, it is confirmed that the enhanced optical absorption, accelerated interfacial charge carrier transfer and effective separation of photogenerated electron-hole pairs induced by CQDs decoration account for the enhancement of CQDs/Fe₂O₃ nanowire arrays in photoelectrochemical application.     

煤矿井下风水管路压力在线监测系统的研究与应用

为提高井下管路供风、供水的安全性、可靠性，以工业环网作为网络通信平台，通过分站采集数据上传至地面，实现对煤矿井下供风、供水管道的远程实时监控及远程控制，及时发现管网故障，提高维护效率、降低损失，保障供风、供水质量，达到科学预警、降低成本、提高效率的目的。     

Solomon某金矿浸出工艺探索研究

本文对Solomon某金矿进行可行性工艺探索性研究,结果表明,混合原矿,矿石粒度为20 mm,柱浸浸出60 d,渣液合计浸出率为73.19%;浮选金精矿,超细磨粒度为P80=13 μm,金浸出率为68.90%,焙烧预氧化-细磨-氰化,可使金的浸出率提高到91.50%;加压预氧化-氰化后金的浸出率可以达到97.02%。     

废石回收原矿选铜药剂工业优化试验研究

某选矿厂为实现铜资源的高效综合利用,从废石中大量回收原矿,导致原矿性质发生了较大改变,原矿综合铜品位降至0.5%左右。为保证选别质量,确保选厂生产顺利进行,对选厂混合原矿的性质进行了调查,调查结果显示,该选厂混合原矿的铜矿物含量较高,铜综合品位在大于0.5%,且大部分已单体解离。根据该混合原矿的性质,分别进行了选铜捕收剂优化试验,选铜抑锌优化试验,选铜抑砷优化试验,试验结果表明,对该混合原矿进行上述优化试验后,铜精矿中铜的品位可达23.66%,铜回收率可达91.52%,符合选厂要求,实现了铜资源的高效回收。     

Fabrication and Characterization of Highly Oriented Composite Nanofibers with Excellent Mechanical Strength and Thermal Stability

Here, highly‐oriented poly(m‐phenylene isophthalamide)/polyacrylonitrile multi‐walled carbon nanotube (PMIA/PAN‐MWCNT) composite nanofiber membranes with excellent mechanical strength and thermal stability are successfully produced using electrospinning. It is demonstrated that the cooperation of multi‐walled carbon nanotubes (MWCNT) and high‐speed rotating collection is beneficial to the acquisition of highly oriented fibers and effectively improves the mechanical strength of the membrane along the orientation direction. Specifically, the tensile stress of poly(m‐phenylene isophthalamide)/polyacrylonitrile (PMIA/PAN) membrane is enhanced significantly from 10.6 to 20.7 MPa, benefiting from the highly oriented alignment of the fibers as well as the reinforcing effect of MWCNTs on the fibers. Furthermore, the stressing process of single fiber and fiber aggregates is carefully simulated, and the influence of MWCNTs on the mechanical properties of PMIA/PAN‐MWCNT membranes is analyzed comprehensively, providing a meaningful auxiliary means for the study of mechanical properties. In addition, the composite nanofiber membrane has the advantages of both PMIA and PAN, possessing high temperature resistance, flame‐retardancy, and chemical stability, for an ideal high‐temperature material. In short, the as‐prepared PMIA/PAN‐MWCNT composite membrane with excellent comprehensive property emerges a promising application in many fields, especially in high‐tech.     

MSCT多期增强扫描在肾脏透明细胞癌中的诊断价值

目的探讨多排螺旋CT(MSCT)多期增强扫描在肾脏透明细胞癌诊断中的规律性,提高对该肿瘤诊断水平。方法回顾性分析2016年1月~2018年6月14例均经手术切除病理证实为肾脏透明细胞癌患者的CT影像资料,所有病例均行MSCT平扫及多期动态增强扫描。结果14例肾脏透明细胞癌形态大多数呈圆形或者类圆形,瘤体最大径范围1.7cm^11.3cm,平均(4.8±1.4)cm,13例CT平扫时肿瘤密度不均匀,呈等低密度,1例呈等密度;12例出现坏死囊变,钙化1例,伴肾盂、肾盏侵犯2例;动态增强扫描可见12例包膜完整,1例均匀性强化,13例不均匀性强化;引入对比剂后皮质期,出现10例病灶强化幅度大于肾皮质,而仅4例低于肾皮质,三期平均CT值分别为110±30Hu,90±15Hu及75±14Hu,其中在实质期出现13例肿瘤强化幅度小于肾实质,仅1例大于肾实质。结论引入对比剂动态增强扫描后,肾脏透明细胞癌在皮质期明显不均匀强化,实质期强化幅度下降显著,呈现出典型的“快进快出”血流动力学强化方式,且肿瘤容易出现坏死、囊变为其特点。     

锂电池回收再生石墨增强水泥性能研究

废弃锂离子电池的负极活性材料主要为石墨,现阶段对于废弃锂离子电池中的石墨主要采用填埋等方法进行处理,造成了资源的浪费和环境的污染。现有的研究表明,废弃锂离子电池中的石墨经高温热解及酸浸处理后可以得到纯净的再生石墨,采用再生石墨增强水泥基复合材料的力学性能和电学性能。结果表明：再生石墨的引入可以增强材料的抗压性能和抗折性能,最大增幅分别达到了57.3%和84.4%。此外,再生石墨的加入有效降低了材料的电阻率,减少了极化时间,当再生石墨的掺加量为3%时,养护28 d后材料的电阻率仅为249 Ω·cm。该复合材料还具有典型的压敏特性。所制备的复合材料有望用于混凝土材料结构的实时动态监测。此外,对于废弃锂离子电池的全组分回收利用及功能水泥材料的研发具有重要意义。     

Effect of chlorination and fluorination of benzothiadiazole on the performance of polymer solar cells

In order to explore the effects of chlorine and fluorine on photophysical properties and the differences, in this work, we synthesized five new polymers, P1 – P5 , in which benzo[1,2-b:4,5-b]dithiophene as the electron donating and benzothiadiazole as electron withdrawing. Analysis of these five polymers showed that the introduction of Cl and F atoms can deeper the highest occupied molecular orbital of these polymers and enhance the absorption of light by the species, thereby improving V_oc and J_sc. Chlorination has a stronger ability to reduce energy levels and broaden the absorption spectrum compared to fluorination. Among them, P2 showed an efficiency of 4.08% with J_sc of 11.28 mA/cm², V_oc of 0.79 V, and fill factor (FF) of 0.45. Since chlorination is easier than fluorination in terms of synthesis, it is advantageous for practical applications. Therefore, we think that chlorination should not be ignored when designing high efficiency photovoltaic materials, especially when their fluorinated counterparts have proven to have good properties.     

循环流化床脱硫灰用于水泥生产的研究

褐煤作燃料热电厂产生的循环流化床脱硫灰应用于我公司2 500 t/d新型干法窑生产线水泥生产，由于褐煤中全硫含量偏高且波动大，由此致使脱硫过程中脱硫剂比例变化波动也大，将熟料、矿渣、脱硫灰分别用小磨粉磨后进行试验，在试验基础上，除了对该脱硫灰超细粉磨外，同时必须要解决脱硫灰的均化和f-CaO消解问题，通过技术改造使系统设备、工艺更加适合采用脱硫灰复掺技术。