水泥厂球(管)磨机增效技术的开发与应用

球(管)磨机增效的途径有二:一是从粉磨机理出发,利用磨机本体相关零部件的不同功能对磨机结构进行科学的设计与改造;二是对粉磨系统进行优化。包括对入磨物料的科学处理,采用适宜的工艺流程及辅机设备等。     

The influence of humidity on dry separation of granular particles based on geometrical characteristics

The influence of atmospheric humidity on dry separation of particles was experimentally investigated, making use of the difference in particle motion on an inclined wall, due to different geometrical characteristics. Using a tilted rotating cylinder with blades, glass beads with size and shape distributions were separated according to their geometrical characteristics under various levels of humidity. Fractional recovery of particles is discussed in relation to shape and size of particle and humidity. An angle of repose of the particles was also measured in order to determine the influence of adhesion force, which is closely related to humidity.Glass beads were separated predominantly based on their shape characteristics. Fractional recovery of particles changes strongly around a relative humidity of 60-70%, at which point the angle of repose also changes markedly. The influence of interaction between particles, which becomes significant for smaller particles, was found to reduce the fractional recovery and diminish the influence of humidity.     

Polypyrrole composite membrane with high permeability prepared by interfacial polymerization

Novel polypyrrole (PPy)/polydimethylsiloxane (PDMS) composite membrane was prepared by interfacial polymerization to make a very effective gas separation membrane. We found that Polymerized PPy films as thin as ～200 nm could be chemically synthesized as freestanding membranes by using the interfacial polymerization technique. Additionally, we show that difference morphology of PPys films was obtained by controlling polymerization rate and more dense films were formed at low polymerization rate. Wide X-ray diffraction study showed the d spacing value of the PPy film decreased from 4.89 å to 3.67 å by the rate of polymerization decreases. According to d spacing value decrease, selectivity of a PPy composite membrane was increased dramatically and permeability was reduced gradually. This high selectivity was derived from d spacing closed to the kinetic diameter of nitrogen. These results indicated that the permeability is controlled by the diffusion coefficient, reflecting the packed structure of the PPy film. The highest selectivity value of composite membrane that was prepared by interfacial polymerization was O₂/N₂=17.2 and permeability for O₂ was 40.2 barrer.     

Novel method for separation and screening of lubricant-degrading microorganisms and bacterial biodegradation☆

With the rapid increase of lubricant consumption,oil contamination becomes more serious.Biotreatment is an important method to remove oil contamination with some advantages.In this study,acclimatized oilcontaminated soil and used lubricating oil were sampled to isolate lubricant-degrading strains by several methods.51 isolates were obtained and 24-well plates were employed to assess bacterial potential in highthroughput screening.The method was noted for the prominence of oil–water two-phase system with saving chemicals,shortening cycles and lessening workloads.In order to decrease inaccuracy,subculture and resting cells were inoculated into mineral salt medium with 200 μl oil in well plates for the cultivation at 37 °C for 5and 7 days,and the biodegradation potential was characterized by the changes of oil film and cell density.With appropriate evaluation by shaking flask tests,5 isolates were retained for their potentials with the maximum biodegradation from 1500 to 2200 mg · L~(-1)and identified as Acidovorax citrulli,Pseudomonas balearica,Acinetobacter johnsonii(two isolates with different biodegradation potentials)and Acidovorax avenae using 16 S r RNA sequencing analysis.Also,lipase activity was determined using indicator titration and p-nitrophenyl palmitate(p-NPP)methods.The results indicated that only p-NPP was successful to test lipase activity with the range of 1.93–6.29 U · ml~(-1).Although these five strains could degrade 1000 mg · L~(-1)lubricating oil in158–168 h,there existed distinct difference in enzyme activity,which demonstrates that lipase activity could not be used as the criterion to evaluate microbial biodegradation potential for petroleum hydrocarbons.     

Electrodeposited iodide ions imprinted polypyrrole@bismuth oxyiodide film for an electrochemically switched renewable extractor towards iodide ions

Effective extraction and regeneration of radioactive iodide is one of urgent concerns for the safe utilization of nuclear energy. As a novel environmentally benign ion separation technique, electrochemically switched ion extraction(ESIE) process can be applied for effective capture and recovery of iodide ions(I^-). Herein, a novel kelp seaweed-like core/shell I^-imprinted polypyrrole@bismuth oxyiodide(PPy/I^-@BiOI) composite film is successfully prepared for the sel...     

Recent advances in nanofiltration,reverse osmosis membranes and their applications in biomedical separation field

In the face of human society’s great requirements for health industry, and the much stricter safety and quality standards in the biomedical industry, the demand for advanced membrane separation technologies continues to rapidly grow in the world. Nanofiltration(NF) and reverse osmosis(RO) as the highefficient, low energy consumption, and environmental friendly membrane separation techniques, show great promise in the application of biomedical separation field. The chemical compositions, microstr...     

Fabrication of nickel oxide functionalized zeolite USY composite as a promising adsorbent for CO2 capture

Adsorption process is considered to be the most promising alternative for the CO₂ capture to the traditional energy-intensive amine absorption process, and the development of feasible and efficient CO₂ adsorbents is still a challenge. In this work, the NiO@USY (ultrastable Y) composites with different NiO loadings were prepared for the CO₂ adsorption using Ni(NO₃)₂ as the precursor. The composites were characterized by X-ray photoelectron spectroscopy, X-ray diffraction, nitrogen adsorption–desorption test, scanning electron microscopy analysis, and thermogravimetric analysis, and were evaluated for the CO₂ adsorption capacity, CO₂/N₂ adsorption selectivity and CO₂ cycle adsorption capacity. The characterization results show that after the activation at 423 K, the Ni(NO₃)₂ species were well dispersed into the surface of zeolite USY, and after the further activation at 823 K, Ni(NO₃)₂ could be converted into highly dispersed NiO. The adsorption results show that the presence of the active component NiO plays an important role in improving the CO₂ adsorption performance, and the NiO@USY composite with a NiO loading of 1.5 mmol·g^-1 USY support displays a high adsorption capacity and adsorption selectivity for CO₂, and shows a good cycle stability. In addition, the Clausius–Clapeyron equation was used to evaluate the isosteric heat of adsorption of CO₂ on the NiO(1.5)@USY composite, and the heat of adsorption was 17.39–38.34 kJ·mol^-1.     

Designed synthesis of porous carbons for the separation of light hydrocarbons

The separation of light hydrocarbon mixtures (C₁-C₃) generated from petrochemical industry is vital and challenging process for obtaining valuable pure chemical feedstocks. In comparison to the energy intensive conventional separation technologies (cryogenic distillation, absorption and hydrogenation), the adsorptive separation is considered as a low energy cost and high efficiency process. Porous carbons have been demonstrated as excellent adsorbents for the separation of light hydrocarbons, owing to their designable structure and tailorable properties. This review summarizes the recent advances of using porous carbons as adsorbents for the separation of light hydrocarbons, including methane/nitrogen, methane/alkane, methane/carbon dioxide, ethylene/ethane and propylene/propane. We discuss the separation mechanisms and highlight the material features including pore structure, surface chemistry and target molecular properties that determine the separation performance. Furthermore, the challenges and development direction associated with carbonaceous adsorbents for light hydrocarbon separation are discussed, meanwhile the guidelines for the design of porous carbons are proposed.     

Two-dimensional graphitic carbon nitride for membrane separation

Recent years, membrane separation technology has attracted significant research attention because of the efficient and environmentally friendly operation. The selection of suitable materials to improve the membrane selectivity, permeability and other properties has become a topic of vital research relevance. Two-dimensional (2D) materials, a novel family of multifunctional materials, are widely used in membrane separation due to their unique structure and properties. In this respect, as a novel 2D material, graphitic carbon nitride (g-C₃N₄) have found specific attention in membrane separation. This study reviews the application of carbon nitride in gas separation membranes, pervaporation membranes, nanofiltration membranes, reverse osmosis membranes, ion exchange membranes and catalytic membranes, along with describing the separation mechanisms.     

Design and optimization of an integrated process for the purification of propylene oxide and the separation of propylene glycol by-product

It is difficult to separate the methanol and hydrocarbons in the propylene oxide (PO) purification process due to their forming azeotrope. As for this, a novel PO separation process, in that the deionized water is employed as extractant and 1,2-propylene glycol (MPG) that is formed from the PO hydrolysis reaction is recovered, is presented in this work. The salient feature of this process is that both the non-catalyzed reactions of PO hydrolysis to form MPG and dipropylene glycol (DPG) are simultaneously considered and MPG by-product with high purity is obtained in virtue of the deionized water as reflux liquid and side take-off in MPG column. In addition, the ionic liquid (IL) extractant is screened through the conductor-like screening model for segment activity coefficient (COSMO-SAC) and the comparisons of separation efficiency between the IL and normal octane (nC₈) extractant for the separation of PO and 2-methylpentane are made. With the non-random two-liquid (NRTL) thermodynamic model, the simulation and optimization design for the full flow sheet are performed and the effects of the key operation parameters such as solvent ratio, theoretical stages, feeding stage etc. on separation efficiency are detailedly discussed. The results show that the mass purity and the mass yield of PO can be up to 99.99% and 99.0%, and the condenser duty, reboiler duty and PO loss in the process with IL extractant can be decreased by 69.66%, 30.21% and 78.86% compared to ones with nC₈. The total annual cost (TAC) calculation also suggests that the TAC would be significantly reduced if using IL in replace of nC₈ for the investigated process. The presented results would provide a useful guide for improving the quality of PO product and the economic efficiency of industrial plant.