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Refractoriness of chrome minerals imposes challenges during chrome ore pelletization process. This study is conducted to find suitable additives to improve chrome ore pelletization and pellet properties. Two types of additives (carbonaceous heating additives and binding fluxes) have been explored to improve pellet induration in pre-heating and elevated temperature zone of a shaft furnace. Ten different types of carbonaceous heating additives (rice husk powder, coke fines, anthracite coal, Indian coal, South African coal, Indonesian coal, graphite powder, carbon soot, pet coke, charcoal) were tested and found that rice husk powder and carbon soot are the most effective additives to improve pellet properties in the shaft furnace pre-heating zone. Rice husk dosing improves pellet strength by 31% (31.76 to 41.90 kgf) in the pre-heating zone which helps pellets to maintain their shape and size, this in terms improve the pellet bed permeability and gas flow during sintering. Seven diverse types of binding fluxes (Dolomite, Magnesium-chromite fines, Magnesium-carbon fines, MgCl2, Na3AlF6, MgO powder, and DRI-additive) were studied in the lab. Cryolite dosing between 0.25% to 2% in pellet mix improved pellet compressive strength by 190% (63 to184 kgf) and reduced pellet swelling by 30%. A pellet mix which contained 95% ore fines, 2% bentonite, 2% rice husk powder, 1% cryolite and 14% moisture has been identified as an optimized pellet mix for producing pellets with 197 kgf/pellet compressive strength. The pellets produced using optimized pellet mix also showed superior metallurgical properties during smelting reduction. It can improve the overall plant productivity economically. [ABSTRACT FROM AUTHOR]

Alkyne annulation represents a versatile and powerful strategy for the assembly of structurally complex compounds. Recent advances successfully enabled electrocatalytic alkyne annulations, significantly expanding the potential applications of this promising technique towards sustainable synthesis. The metallaelectro-catalyzed C–H activation/annulation stands out as a highly efficient approach that leverages electricity, combining the benefits of electrosynthesis with the power of transition-metal catalyzed C–H activation. Particularly attractive is the pairing of the electro-oxidative C–H activation with the valuable hydrogen evolution reaction (HER), thereby addressing the growing demand for green energy solutions. Herein, we provide an overview of the evolution of electrochemical C–H annulations with alkynes for the construction of heterocycles, with a topical focus on the underlying mechanism manifolds. [ABSTRACT FROM AUTHOR]

Plant growth promoting rhizobacteria (PGPR) play a key role in sustainable agricultural practices leading to increased crop productivity. Moreover, PGPR with ability to diminish abiotic stresses like salinity and hydrocarbon contamination in soil, can be developed into potent biofertilizers with maximum ecological benefits. Sundarbans mangrove region in West Bengal, a natural reservoir of diverse microbiota is an important source of PGPR adapted to high salinity and other abiotic stresses like hydrocarbon contamination due to oil spillage and water transport systems, rendering the soil unsuitable for farming. In the present study, a potent PGPR has been isolated from rhizospheric soil of Matla riverbed in mangrove areas of Sundarbans, with simultaneous nitrogen fixing, phosphate solubilizing and plant hormone like indole acetic acid (IAA) producing properties as well as high salt tolerance and hydrocarbon bioremediation abilities. The strain has been identified as Pseudomonas aeruginosa JCM 5962 (NCBI Accession number MK544832.1) on the basis of 16S rRNA analysis. The isolated Pseudomonas aeruginosa strain showed atmospheric nitrogen fixation (3612 ± 2 mg N/ Kg of soil), highest phosphate solubilization index of 3.0 ± 0.06 and 37.14 µg/mL of IAA production. This potent strain also showed salt tolerance upto 7% in culture broth and an uptake of 18.72% of salt. Highest hydrocarbon degradation was shown by this strain in presence of diesel as the sole carbon source. The isolated Pseudomonas aeruginosa strain showed overall improvement in growth of Abelmoschus esculentus (Okra) plants in pot experiments in different conditions like absence of any abiotic stress, presence of 5% salt stress and presence of 1% diesel contaminant. These results indicate that Pseudomonas aeruginosa JCM 5962 can be developed as a potent biofertilizer to be used in agricultural lands of Sundarbans mangrove regions and other areas which are plagued by high salinity and increasing hydrocarbons, particularly petroleum contamination. [ABSTRACT FROM AUTHOR]