Pyrochemical processing of tungsten- and cobalt-containing raw materials

Zarubitskii, O. G.; Orel, V. P.; Dmitruk, B. F.

doi:10.1007/s11167-005-0150-1

Cited by 5 publications

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“…Unfortunately, in recent decades the popularity of the flax plantations has decreased, not only in Poland, but all over the world [30]. This tendency could be explained by several reasons:…”

Section: Introductionmentioning

confidence: 99%

Manipulating cinnamyl alcohol dehydrogenase (CAD) expression in flax affects fibre composition and properties

et al. 2014

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BackgroundIn recent decades cultivation of flax and its application have dramatically decreased. One of the reasons for this is unpredictable quality and properties of flax fibre, because they depend on environmental factors, retting duration and growing conditions. These factors have contribution to the fibre composition, which consists of cellulose, hemicelluloses, lignin and pectin. By far, it is largely established that in flax, lignin reduces an accessibility of enzymes either to pectin, hemicelluloses or cellulose (during retting or in biofuel synthesis and paper production).Therefore, in this study we evaluated composition and properties of flax fibre from plants with silenced CAD (cinnamyl alcohol dehydrogenase) gene, which is key in the lignin biosynthesis. There is evidence that CAD is a useful tool to improve lignin digestibility and/or to lower the lignin levels in plants.ResultsTwo studied lines responded differentially to the introduced modification due to the efficiency of the CAD silencing. Phylogenetic analysis revealed that flax CAD belongs to the “bona-fide” CAD family. CAD down-regulation had an effect in the reduced lignin amount in the flax fibre cell wall and as FT-IR results suggests, disturbed lignin composition and structure. Moreover introduced modification activated a compensatory mechanism which was manifested in the accumulation of cellulose and/or pectin. These changes had putative correlation with observed improved fiber’s tensile strength. Moreover, CAD down-regulation did not disturb at all or has only slight effect on flax plants’ development in vivo, however, the resistance against flax major pathogen Fusarium oxysporum decreased slightly. The modification positively affected fibre possessing; it resulted in more uniform retting.ConclusionThe major finding of our paper is that the modification targeted directly to block lignin synthesis caused not only reduced lignin level in fibre, but also affected amount and organization of cellulose and pectin. However, to conclude that all observed changes are trustworthy and correlated exclusively to CAD repression, further analysis of the modified plants genome is necessary. Secondly, this is one of the first studies on the crop from the low-lignin plants from the field trail which demonstrates that such plants could be successfully cultivated in a field.

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Section: Introductionmentioning

confidence: 99%

Manipulating cinnamyl alcohol dehydrogenase (CAD) expression in flax affects fibre composition and properties

et al. 2014

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“…At the same time niobium transfers into solution, tungsten does not dissolve. Electrolysis is carried out at a potential of 0.3...0.45 V relative to the silver chloride reference electrode [17,18]. Before electrolysis, the raw material is being ground.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical Processing of Tungsten-Cobalt Pseudoalloys, Receiving Tungsten Powder for Modification of Aramid Tissue

Tulskiy

Lyashok

Gomozov

et al. 2022

SSP

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Electrochemical research is focused on the tungsten extraction during acid electrochemical treatment of WC-Co pseudoalloy in chloride solutions. The target resulted products of the treatment are: tungsten oxide (VI), tungsten powder with a given particle size distribution (2…3 μm). Based on the analysis of kinetics, the mechanism of dissolution of the WC-Co pseudoalloy in a solution of 2.5 mol∙dm-3 HCl and with the addition of HF was proposed. It was found that a well-soluble higher tungsten chloride is formed on the surface of the pseudoalloy, which is eventually hydrolyzed in aqueous solution to form tungsten oxides. The dispersion control levers were investigated and the technological parameters of obtaining tungsten metal powder from low-temperature ionic alloys (NaCl-KCl-CsBr-NaF) were determined, which make it possible to obtain tungsten metal powder of a given particle size distribution. It is stated that the use of tungsten powder (W or WO3) for the modification of aramid fiber can significantly increase the heat resistance of aramid fabric and reduce its wear

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“…Developed technologies of processing of waste hard metals are mainly based on chemical techniques. However, due to environmental restriction, some of the developed technologies are not functionally in many Western countries [9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

“…Chemical, physico-chemical, electrochemical and mechanical methods are used for recycling and valorization of components from secondary raw material based on tungsten [2,6,[12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

Integrated procedure for recycling and valorization of useful components from secondary raw materials based on hard metals

et al. 2017

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Wide application of hard metals requires increased consumption of their constituents. Their high cost and scarcity impose the need for finding new, both ecologically and economically justified ways for their production. In presented research, on the basis of previous research, a review of an integrated technological procedure of recycling and valorization of useful components from hard metals secondary raw materials is given.Integrated procedure for processing of hard metal's waste enables the preparation of a wide range of powders with required properties, a high efficiency and reducing the duration of individual stages of procedures for their processing. Therefore, besides conservation of natural resources there are also significant economic and energetic benefits. The developed technological procedure is in service of sustainable development.

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Pyrochemical processing of tungsten- and cobalt-containing raw materials

Cited by 5 publications

References 0 publications

Manipulating cinnamyl alcohol dehydrogenase (CAD) expression in flax affects fibre composition and properties

Manipulating cinnamyl alcohol dehydrogenase (CAD) expression in flax affects fibre composition and properties

Electrochemical Processing of Tungsten-Cobalt Pseudoalloys, Receiving Tungsten Powder for Modification of Aramid Tissue

Integrated procedure for recycling and valorization of useful components from secondary raw materials based on hard metals

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