Publications by authors named "Kaixi Jiang"

In this study, combination of wave absorption materials with different loss mechanisms are added into iron ore tailings-blast furnace slag (IOT-BFS) based geopolymers. The employed materials are hollow glass microsphere (HGM), carbon nanotubes (CNT) and carbonyl iron powder (CIP). Microstructures of the geopolymers are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and concrete porous structure analyzer.

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Article Synopsis
  • The study focuses on creating iron ore tailings-blast furnace slag (IOT-BFS)-based geopolymers with adjustable setting times and high compressive strength for civil engineering applications.
  • Key factors influencing the setting time include the content of iron ore tailings, alkali content, liquid-solid ratio, and the modulus of alkaline activators, which were thoroughly analyzed.
  • Results show that adjusting the modulus of the alkaline activator significantly affects the setting time, allowing control from around 3 minutes to 108 minutes, enabling tailored geopolymers for diverse construction needs.
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Nitrogen-cycling processes in the deep sea remain understudied. This study investigates the distribution of nitrogen-cycling microbial communities in the deep-sea surface sediments of the western South China Sea, using metagenomic sequencing and real-time fluorescent quantitative PCR techniques to analyze their composition and abundance, and the effects of 11 environmental parameters, including NH-N, NO-N, NO-N, PO-P, total nitrogen (TN), total organic carbon (TOC), C/N ratio, pH, electrical conductivity (EC), SO, and Cl. The phylum- and species-level microbial community compositions show that five sites can be grouped as a major cluster, with sites S1 and S9 forming a sub-cluster, and sites S13, S19, and S26 forming the other; whereas sites S3 and S5 constitute a separate cluster.

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In the minerals processing industry, the surface chemistry of mineral particles and its real-time detection can significantly enhance process performance, and ultimately leading to automotive and intelligent control. The adsorption of collector molecule onto bulk mineral specimens could be investigated with the help of shell-isolated nanoparticle enhanced Raman spectroscopy (SHINERS). However, this method is unsuitable for the online detection of particles fluid consisted of micro-sized chalcocite that encountered in industrial production processes.

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Adding organics in the process of geopolymer synthesis can combine the functional groups of organics with the three-dimensional structure of geopolymer, thus changing the properties of geopolymer such as compressive strength, flexural strength, and acid resistance. In this work, excellent mechanical properties and acid resistance of metakaolin-blast furnance slag (Mk-BFS)-based geopolymer were synthesized by the incorporation of chitosan. The formation of sodium-alumino-silicate-hydrate (N-A-S-H) gel and calium-alumino-silicate-hydrate (C-A-S-H) gel in geopolymerization were characterized by Si nuclear magnetic resonance (NMR).

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A significant amount of coal fly ash is generated and this type of waste material causes severe environmental hazards. Metal (Al and Fe) extraction from coal fly ash is beneficial to the resource utilization of waste coal fly ash. However, the coexistence of Al and Fe in coal fly ash means that the separation of Al and Fe is required, which is a key and difficult step to prepare high value-added products from coal fly ash.

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Fly ash is one of the largest solid waste and causes serious environment problems. Extraction of Al(OH) from fly ash is beneficial to environment and economy. We developed a clean electrolysis method to generate hydroxyl groups in situ to extract Al(OH) from fly ash leachate without adding chemicals or using expensive membranes, avoiding the introduction of new impurities, secondary pollutants generation, and membrane limitations.

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Methyltrimethyltridecylchromans (MTTCs) are structurally similar to tocopherols, which were identified in large numbers of source rocks and crude oils (Pleistocene to Early Cambrian). The occurrence of MTTCs was widely used as a proxy indicator of paleosalinity in the field of organic geochemistry. However, their origin and geological formation pathway still remain greatly debated.

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