Wykorzystanie drobnouziarnionych odpadów ze wzbogacania węgla w Rejonie Ostrava-Karwina (OKD)

W artykule przedstawiono kierunki wykorzystania drobnouziarnionych odpadów ze wzbogacania węgli zdeponowanych w Rejonie Ostrava-Karwina w Republice Czeskiej. Odpady to w większości odpady poflotacyjne, zdeponowane w stawach osadowych. Pokazano możliwości wykorzystania odpadów w energetyce, produkcji materiałów budowlanych oraz do rekultywacji. Przedstawiono wyniki badania możliwości produkcji paliwa na bazie odpadów powęglowych z dodatkiem odpadowego PET. Badania technologii produkcji paliwa z odpadów przeprowadzono dla różnych receptur obejmujących następujące składniki: • mieszanina węgla kamiennego z węglem brunatnym o zawartości siarki Sd = 1%, i wartości ciepła spalania Qid = 17.60 MJ/kg, • odpadowy PET, • plastyfikator, woda, odpady z produkcji mąki. Uzyskano paliwa alternatywne w formie peletów o wartości opałowej od 13.66 MJ/kg do 18.55 MJ/kg

Reflotation of Coal Slurries from OKD company, Mine Lazy

The goal of the work is a verification of selective flotation on the black coal slurries sampled from slurry ponds of Mine Lazy, OKD company. Reflotation was realized with 6 collectors: Flotakol NX, Flotalex Ekofol 440, Montanol, MP 125 and AF 2. The technology of main flotation was applied. The variance analysis was used for the selectivity evaluation of particular collectors, whereby both the yield and flotation concentrate quality were tested. The goal of the flotation experiments was to achieve the flotation concentrate quality under 10% of ash. From the results follows that by using basic flotation it is possible (with the slurry samples) to reach the marketable coal concentrates with the ash content under 10% by Flotalex collector application

Nanocrystalline Cellulose/Polyvinylpyrrolidone Fibrous Composites Prepared by Electrospinning and Thermal Crosslinking

Nanocellulose/polyvinylpyrrolidone (nCel/PVP) fibrous composite materials containing rod-like nanocrystalline cellulose particles with the lengths varying in the range from 100 to 2000 nm were prepared by using DC electrospinning. The particle size had a strong effect on the precursor viscosity, process efficiency, and resulting fiber diameter. The thermal crosslinking of nCel/PVP composite nanofibers with up to 1.0 :  8.0 nCel/PVP weight ratio resulted in fibrous membranes with textural, air transport, and mass swelling properties varying significantly with the size of cellulose particles. The presence of nCel particles increased the oxidation resistance of PVP during the crosslinking and affected the morphological changes of nCel/PVP fibrous membranes in aqueous solutions. Particles with the smallest size improved the strength of the membrane but decreased its mass swelling capacity, whereas the larger particles led to a more porous and flexible, but mechanically weaker, membrane structure with a higher swelling ability. Thus, by using the nCel particles of different size and shape, the properties of nCel/PVP composite fibrous membranes can be tailored to a specific application

Nanocrystalline Cellulose/Polyvinylpyrrolidone Fibrous Composites Prepared by Electrospinning and Thermal Crosslinking

Nanocellulose/polyvinylpyrrolidone (nCel/PVP) fibrous composite materials containing rod-like nanocrystalline cellulose particles with the lengths varying in the range from 100 to 2000 nm were prepared by using DC electrospinning. The particle size had a strong effect on the precursor viscosity, process efficiency, and resulting fiber diameter. The thermal crosslinking of nCel/PVP composite nanofibers with up to 1.0 : 8.0 nCel/PVP weight ratio resulted in fibrous membranes with textural, air transport, and mass swelling properties varying significantly with the size of cellulose particles. The presence of nCel particles increased the oxidation resistance of PVP during the crosslinking and affected the morphological changes of nCel/PVP fibrous membranes in aqueous solutions. Particles with the smallest size improved the strength of the membrane but decreased its mass swelling capacity, whereas the larger particles led to a more porous and flexible, but mechanically weaker, membrane structure with a higher swelling ability. Thus, by using the nCel particles of different size and shape, the properties of nCel/PVP composite fibrous membranes can be tailored to a specific application

Convergent morphology in alpinieae (Zingiberaceae): Recircumscribing amomum as a monophyletic genus

The tropical ginger genus Amomum (Zingiberaceae) has always posed challenges for classification based on morphological characters. Previous molecular phylogenetic studies showed Amomum to be paraphyletic but limited sampling and absence of the data of the type Amomum subulatum made it impossible to resolve the paraphyly and make nomenclatural changes. Here, Amomum is further investigated in a multi-marker phylogenetic framework using matK and nrITS including multiple accessions of the type, the genus Elettaria and additional accessions of Amomum, Alpinia, Elettariopsis, Geocharis, Geostachys and Hornstedtia. Amomum is shown to consist of nine clades and Alpinia of six. The genera Elettaria, Elettariopsis, Plagiostachys, and species in Hornstedtia are nested within these clades. Morphological studies of species previously subsumed in Amomum support recognition of new genera that correspond to well-delimited clades in the phylogenetic framework presented here. Recircumscription of the paraphyletic genus Amomum facilitates identification and creates nomenclatural stability. Three genera, Conamomum, Meistera and Wurfbainia, are resurrected, and three new genera Epiamomum, Lanxangia and Sundamomum are described, together with a key to the genera and a nomenclatural synopsis placing 384 specific names (incl. all synonyms) into the new generic framework. Of these 129 represent new combinations and 3 are replacement names. Types of Geocharis and Geostachys are designated. Further studies and specific sampling will be needed to resolve other branches of Alpinioideae containing other polyphyletic genera. © International Association for Plant Taxonomy (IAPT) 2018, all rights reserved

Convergent morphology in alpinieae (Zingiberaceae): Recircumscribing amomum as a monophyletic genus

The tropical ginger genus Amomum (Zingiberaceae) has always posed challenges for classification based on morphological characters. Previous molecular phylogenetic studies showed Amomum to be paraphyletic but limited sampling and absence of the data of the type Amomum subulatum made it impossible to resolve the paraphyly and make nomenclatural changes. Here, Amomum is further investigated in a multi-marker phylogenetic framework using matK and nrITS including multiple accessions of the type, the genus Elettaria and additional accessions of Amomum, Alpinia, Elettariopsis, Geocharis, Geostachys and Hornstedtia. Amomum is shown to consist of nine clades and Alpinia of six. The genera Elettaria, Elettariopsis, Plagiostachys, and species in Hornstedtia are nested within these clades. Morphological studies of species previously subsumed in Amomum support recognition of new genera that correspond to well-delimited clades in the phylogenetic framework presented here. Recircumscription of the paraphyletic genus Amomum facilitates identification and creates nomenclatural stability. Three genera, Conamomum, Meistera and Wurfbainia, are resurrected, and three new genera Epiamomum, Lanxangia and Sundamomum are described, together with a key to the genera and a nomenclatural synopsis placing 384 specific names (incl. all synonyms) into the new generic framework. Of these 129 represent new combinations and 3 are replacement names. Types of Geocharis and Geostachys are designated. Further studies and specific sampling will be needed to resolve other branches of Alpinioideae containing other polyphyletic genera. © International Association for Plant Taxonomy (IAPT) 2018, all rights reserved