Medium-temperature calcination and acid pressure leaching extract the Al2O3 from coal gangue: activation mechanism and kinetic analysis.

Bauxite is an important strategic resource, and it is facing with the problem of balance between high demand of bauxite ore and low resource of bauxite reserves in China. This research takes the Fuxin coal gangue as the object and extracts Al2O3 by medium-temperature calcination and acid pressure leaching process. The results show that at a calcination temperature of 650 °C, calcination time of 2 h, acid pressure leaching temperature of 160 °C and acid pressure leaching time of 6 h, the extraction ratio of Al2O3 reaches 80.19%. Furthermore, the research finding that the complete activation temperatures of kaolinite and muscovite are 650 °C and 850 °C, respectively, and the decomposition reactions of active Si, active Al, and metakaolinite occur above 800 °C, which leads to a low extraction ratio of Al2O3. The acid pressure leaching process can directly destroy the muscovite structure at a calcination temperature of 650 °C. The acid pressure leaching kinetic equations are studied by three kinetic models, and the apparent activation energies of the reactions are calculated by the Arrhenius formula. The results show that acid pressure leaching is subject to solid residue in-layer diffusion control, and the kinetic equation is "". The apparent activation energy is 13.48 kJ mol-1.

Preparation of a High-Silicon ZSM-5 Molecular Sieve Using Only Coal Gangue as the Silicon and Aluminum Sources.

The traditional preparation of ZSM-5 molecular sieves relies on chemical reagents to provide silicon and aluminum sources, which are limited as raw materials and cannot be commonly used in production practice. Using coal gangue as the raw material and using medium-temperature chlorination roasting and the pressure acid leaching process to control the silicon-aluminum ratio [n(Si/Al)] of coal gangue, a ZSM-5 molecular sieve was prepared using the alkali melting hydrothermal method. The pressure acid leaching process solved the limitation that kaolinite and mica cannot simultaneously be activated. Under optimal conditions, the n(Si/Al) of the coal gangue increased from 6.23 to 26.14 and complied with the requirements for the synthesis n(Si/Al) of a ZSM-5 molecular sieve. The effect of n(Si/Al) on the preparation of the ZSM-5 molecular sieve was studied. Finally, spherical granular ZSM-5 molecular sieve material with a microporous specific surface area of 169.6329 m2/g, an average pore diameter of 0.6285 nm, and a pore volume of 0.0988 cm3/g was prepared. Providing ideas for the high-value utilization of coal gangue, it is significant for solving the problem of coal gangue solid waste, as well as the problem of ZSM-5 molecular sieve feed stock.

Long Circulating Cancer Cell-Targeted Bionic Nanocarriers Enable Synergistic Combinatorial Therapy in Colon Cancer.

Cancer nanomedicine treatment aims to achieve highly specific targeting and localization to cancer cells. Coating of nanoparticles with cell membranes endows them with homologous cellular mimicry, enabling nanoparticles to acquire new functions and properties, including homologous targeting and long circulation in vivo, and can enhance internalization by homologous cancer cells. Herein, we fused a human-derived HCT116 colon cancer cell membrane (cM) with a red blood cell membrane (rM) to fabricate an erythrocyte-cancer cell hybrid membrane (hM). Oxaliplatin and chlorin e6 (Ce6) co-encapsulated reactive oxygen species-responsive nanoparticles (NPOC) were camouflaged by hM and obtained a hybrid biomimetic nanomedicine (denoted as hNPOC) for colon cancer therapy. hNPOC exhibited prolonged circulation time and recognized homologous targeting ability in vivo since both rM and HCT116 cM proteins were maintained on the hNPOC surface. hNPOC showed enhanced homologous cell uptake in vitro and considerable homologous self-localization in vivo, producing effective synergistic chemophotodynamic therapy efficacy under irradiation with a homologous HCT116 tumor compared to that with a heterologous tumor. Together, the biomimetic hNPOC nanoparticles showed prolonged blood circulation and preferential cancer cell-targeted function in vivo to provide a bioinspired strategy for chemophotodynamic synergistic therapy of colon cancer.

Preparation, Characterization and Performances of Powdered Polycarboxylate Superplasticizer with Bulk Polymerization.

A polycarboxylate superplasticizer (PCE) was synthesized in a non-solvent system with bulk polymerization and then was pulverized into powdered form to achieve a rapid transportation and convenient preparation. PCE synthesized by using isopentenyl polyethylene glycol (TPEG) or isobutenyl polyethylene glycol (IPEG) as a macromonomer exhibited the best fluidities and retaining properties at 80 °C and 75 °C, respectively. Besides, azobisisobutyronitrile (AIBN) was suitable as an initiator, and the fumaric acid was suitable as the third monomer. The test results of ¹H nuclear magnetic resonance (¹H NMR) confirmed the occurrences of polymerization, and the measurement results of molecular weight and distribution showed that PCE molecular weight characteristics were in accordance with their fluidity properties in cement paste. The application performances in cement showed that PCEs with the best paste fluidity retentions had the longest final setting time and the shortest setting time interval, and the PCEs with good fluidity properties can obviously delay the hydration process and lower the hydration heat. Accordingly, this is a novel, energy-saving and economical method to prepare powdered PCE in the field of concrete admixtures.