Solvent recovery from solvent-fine coal slurries by filtration and steam stripping

Dewatering of fine coal is a significant industrial challenge with economic and environmental implications. Due to the lack of suitable dewatering technologies, fine coal particles are often discarded to waste impoundments, leading to substantial loss of valuable natural resources while creating environmental problems. The hydrophobic-hydrophilic separation (HHS) process is a unique solution to this problem. In this process, a recyclable solvent is used to simultaneously remove inorganic impurities (ash) and water from a run-of-mine fine coal slurry. A small amount of recyclable oil (or solvent) is added to a fine coal slurry so that the solvent can spontaneously displace the water from the surface of coal particles. The spent solvent is subsequently recovered and recycled in a closed loop. Here, we report the results obtained using two different solvents, i.e., pentane and hexane, to de-ash and dewater ultrafine coal and recover the spent solvent by filtration, followed by steam stripping. Most of the spent solvent can be recovered during the filtration step at 20 psig N₂ and at a 60 s filtration time. The residual solvent left in the cake was then recovered using steam under different conditions. The results showed that the residual solvent concentration could be reduced to <1,400 ppm after 10 s of steam stripping at 150°C and 15 psig

Down-Regulation of MicroRNA-214 Contributed to the Enhanced Mitochondrial Transcription Factor A and Inhibited Proliferation of Colorectal Cancer Cells

Background/Aims: Colon cancer, also known as colorectal cancer (CRC), is one of the most common malignant tumors globally. Although significant advances have been made for developing novel therapeutics, the mechanisms of progression of colorectal cancer are still poorly understood. Methods: In this study, we identified down-regulation of microRNA-214 (miR-214) as the contributing factor for CRC. Mitochondrial transcription factor A (TFAM) and miR-214 expression in tumor samples from colorectal cancer patients and cancer cell lines were examined by reverse transcription and real-Time PCR (qPCR) or Western Blotting. Results: Our data demonstrated that miR-214 was significantly down-regulated in the tissue samples from CRC patients as well as CRC derived cell lines. TFAM overexpression was also observed in CRC patients and identified as a target for miR-214. Knockdown of TFAM by miR-214 mimics significantly inhibited the proliferation of CRC cell lines. Also, down-regulation of TFAM inhibited nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) nuclear translocation and the expression of NF-κB depended genes. Conclusion: In conclusion, our data suggested that down-regulation of MiR-214 contributed to the enhanced TFAM expression and decreased proliferation of CRC cells

A capillary flow model for filtration

© 2017 Elsevier Ltd A filtration model has been developed by considering the two- and three-phase flows through a filter cake during the cake formation and drying cycle times, respectively. Assuming that the cake consists of well-defined capillaries of identical radius, it is possible to predict filtration kinetics from first principles using the Navier-Stokes equation and capillary pressures. The model parameters have been determined by fitting experimental data to the model using capillary radius and slip length as adjustable parameters. It has been found that use of hydrophobizing reagents greatly improves filtration kinetics and reduces cake moistures, which may be attributed to increases in capillary radius and possibly in slip lengths. Use of a polymeric flocculant also increases filtration kinetics but can cause an increase in cake moisture due to the entrapment of moisture within floc structures

Nanoscale Investigation into Dynamics of Thin Liquid Films during Bouncing and Attachment of Rising Air Bubbles on Hydrophilic and Hydrophobic Surfaces

Investigations on bouncing and attachment of free-rising air bubbles on hydrophobic surfaces have been limited to side-view, high-speed photography of the bubble-plate attachment process. In this work, an investigation of the dynamics as well as stability of thin liquid films (TLFs) between free-rising air bubbles and quartz surfaces was performed using a newly developed multiple-wavelength synchronized reflection interferometry microscopy (SRIM) technique. The effect of surface hydrophobicity on both the stability and critical rupture thickness of TLFs was investigated. Results showed that the TLF ruptured at a critical rupture thickness of 100-1000 nm or beyond during bubble\u27s impact on hydrophobic quartz surfaces. The critical rupture thicknesses varied depending on the surface hydrophobicity as well as surface asperity. A higher surface hydrophobicity, in general, contributed to a higher critical rupture thickness. In addition, the effect of -octanol on the stability of the TLFs was investigated. Results showed that film stability increased with increasing the concentration of -octanol, which was accompanied by a significant decrease in the critical rupture thickness. The present result illustrates, for the first time, the dynamics of TLFs on hydrophobic surfaces under a dynamic condition compared with previous studies under a quasi-equilibrium condition. The information revealed from the present work has a significant implication to many industrial applications, including froth flotation and other biological and semiconductor applications

Improved Separation between Recycled Anode and Cathode Materials from Li-Ion Batteries Using Coarse Flake Particle Flotation

Separation between two recycled electrode active materials from spent Li-ion batteries by a conventional froth flotation method has been challenging due to similarity in their surface hydrophobicity. In this study, a new coarse flake particle flotation technology has been developed to separate the electrode active materials from Li-ion batteries. The new process separates the recycled electrode flake particles effectively at a size range of 212-850 μm by taking advantage of a significant difference in densities between the anode flake materials and cathode flake materials. At a feed size of 212 μm or less, a fraction of recycled cathode particles is floated in the froth layers resulting in a loss of cathode materials in the sink product. At a feed size of 850 μm or above, a small fraction of anode flakes becomes non-floatable, resulting in a decrease in the grade of cathode materials in the sink product. The mechanism has been investigated by induction time measurements, bubble-flake detachment, contact angle measurements, and force analysis. The anode flakes are more hydrophobic than cathode flakes, which is consistent with the result obtained from induction time measurements. A force analysis reveals that the critical size for electrode flake particles being attached to air bubbles varies with advancing contact angle and density. Maintaining a desirable feed size is essential to achieve an optimum separation performance. In this regard, a flotation column is superior to mechanical flotation cells in minimizing size reduction during the flotation process. Lab-scale column flotation trials showed that a good separation between anode and cathode flake particles has been achieved by column flotation with 98-99% purity of cathode flake materials in the sink product at a recovery rate of 96-99%. The present study demonstrates a new process in separating two electrode flake materials from spent Li-ion batteries

Effects of protein sources for milk replacers on growth performance and serum biochemical indexes of suckling calves

This study investigated the effects of protein sources for milk replacers on growth performance and serum biochemical indexes of suckling calves. Fifty Chinese Holstein bull calves with similar BW and age were randomly allocated to 5 groups (1 control and 4 treatments) of 10 calves in each group. Five types of milk replacers were designed to have the same level of energy and protein. The protein source for milk replacers of the control group was full milk protein (MP). The protein source of milk replacers of the 4 treatment groups was composed of MP and one vegetable protein (VP) (30 and 70% of total protein). The 4 types of VP were soybean protein concentrate (SP), hydrolyzed wheat protein (WP), peanut protein concentrate (PP), and rice protein isolate (RP). Results of the experiment showed: 1) there was no significant difference on average daily gain (ADG) and feed:gain ratio (F:G) among the MP, SP and RP groups (P > 0.05), whereas the ADG and F:G of the WP and PP groups were significantly lower compared with the MP group (P  0.05). Thereby the 4 VP milk replacers had no adverse effects on body size of calves; 3) all groups showed no significant difference in the serum contents of urea nitrogen, total protein, albumin, globulin, β-hydroxybutyrate, growth hormone, insulin-like growth factor-1, and the ratio of albumin to globulin (A:G) (P > 0.05). In conclusion, SP or RP (accounts for 70% of the total protein) as calf milk replacers could substitute MP, whereas wheat gluten and PP had a significant adverse effect on growth performance in this experiment

Magnetron sputtered zinc oxide nanorods as thickness-insensitive cathode interlayer for perovskite planar-heterojunction solar cells

Suitable electrode interfacial layers are essential to the high performance of perovskite planar heterojunction solar cells. In this letter, we report magnetron sputtered zinc oxide (ZnO) film as the cathode interlayer for methylammonium lead iodide (CH3NH3PbI3) perovskite solar cell. Scanning electron microscopy and X-ray diffraction analysis demonstrate that the sputtered ZnO films consist of c-Axis aligned nanorods. The solar cells based on this ZnO cathode interlayer showed high short circuit current and power conversion efficiency. Besides, the performance of the device is insensitive to the thickness of ZnO cathode interlayer. Considering the high reliability and maturity of sputtering technique both in lab and industry, we believe that the sputtered ZnO films are promising cathode interlayers for perovskite solar cells, especially in large-scale production

GaN/surface-modified graphitic carbon nitride heterojunction : promising photocatalytic hydrogen evolution materials

The coupling of two-dimensional (2D) layered materials is an effective way to realize photocatalytic hydrogen production. Herein, using first-principles calculations, the photocatalytic properties of GaN/CNs heterojunctions formed by two different graphite-like carbon nitride materials and GaN monolayer are discussed in detail. The results show that the GaN/C2N heterojunction can promote the effective separation of photogenerated electron and hole pairs, which is attributed to its type-II band orientation and high carrier mobility. However, the low overpotential of GaN/C2N for photocatalytic hydrogen production limits the photocatalytic performance. On this basis, we adjust the CBM position of the GaN/C2N heterojunction by applying an electric field to enhance its hydrogen evolution capability. In addition, the GaN/g-C3N4 is a type-I heterojunction, which is suitable for the field of optoelectronic devices. This work broadens the field of vision for the preparation of highly efficient photocatalysts