Wyniki wyszukiwania - BazTech

1

Substitution mechanism of rare earths at fluorapatite characteristic sites : experimental and computational calculations

Xie Jun

Physicochemical Problems of Mineral Processing

|

2023

|

Vol. 59, iss. 2

art. no. 163418

EN

Rare earths (REs) containing phosphate rock is a potential REs resource. The unclear occurrence mechanism of REs in phosphorite limits its further development and utilization. Fluorapatite (FAP) is the main REs-bearing target mineral in phosphorite, the microscopic mechanism of REs entering FAP still needs to be further studied from the electronic scale. In this paper, the doping mechanism of REs in FAP was studied by experiment combined with GGA+U calculation. The XRD, SEM, and FT-IR characterization results of hydrothermal synthesis products showed that REs (La, Ce, Nd, and Y) entered FAP crystal, and one of every 20 Ca atoms was replaced by a REs atom. The GGA+U calculation indicated that La-O/F, Ce-O/F, Nd-O/F, and Y-O/F were ionic bonds in general, and the bonding strength of La-O/F, Ce-O/F, Nd-O/F, and Y-O/F increased gradually with atomic number. The substitution difference of La, Ce, Nd, and Y was mainly caused by the gain and loss of electrons in f and d orbitals. The substitution mechanism of REs at the characteristic sites of Fap was studied, which provided a theoretical reference for the selective recovery of REs from phosphorus blocks.

2

Processing of phosphorites with extraction of phosphorus, obtaining calcium carbide and ferroalloy

Shevko Victor M., Uteyeva Raisa A., Badikova Alexandra D., Tleuova Saltanat T.

Physicochemical Problems of Mineral Processing

|

2023

|

Vol. 59, iss. 6

art. no. 174463

EN

The article considers the results of studying the thermodynamic computer modeling of the interaction of phosphorite (Karatau basin, Kazakhstan) with carbon and coke performed using the HSC-10 software package and electric smelting of the phosphorite with coke and steel shavings in an arc furnace. The modeling allowed us to determine the equilibrium extraction degrees of phosphorus into gas (Р2, Р4), silicon into ferroalloy in the form of iron silicides (FeSi2, FeSi, Fe3Si, Fe5Si3, Si) and calcium into CaС2. At temperatures above 1500 °C, regardless of the amount of iron, the extraction degree of phosphorus into gas is more 99%. The resulting ferroalloy contains 21.2-23.8% of Si, 1.6-2.8% of Al; the calcium carbide has a capacity of 288-325 dm3/kg. The extraction degree of silicon into the alloy was 89.8%, calcium in CaC2 – 72.5%, phosphorus into gas – 99.4%. The ferroalloy, formed at the electric smelting of the Chulaktau phosphorite together with coke and steel shavings and containing 24.9-29.8% of Si, is FS25 grade ferrosilicon, and the formed calcium carbide has a capacity of 278-290 dm3/kg and belongs to the third and second grades. The developed technology makes it possible to increase the degree of phosphorites’ comprehensive use two times (up to 87.5%).

3

Flotation separation of quartz from phosphorite using an imidazole ionic liquid collector and its adsorption mechanism

Zhao Yuanyuan, Xu Wei, Mei Guangjun, Yu Mingming, Yang Siyuan, He Zhan

Physicochemical Problems of Mineral Processing

|

2022

|

Vol. 58, iss. 1

159--168

EN

In this study, an imidazole ionic liquid (dodecyl-tri-methylimidazolium chloride) was employed as a collector to separate quartz from phosphorite. The micro-flotation experiments of a single mineral found that it had selective collecting ability for quartz than phosphorite. Mixed mineral flotation experiments confirmed that efficient separation results could be obtained using the imidazole ionic liquid as the collector. A concentrate with a 31.44% grade of phosphorite could be obtained with a 0.285 kg/Mg collector dosage at neutral pH, which was much better than the traditional collector dodecylamine. The adsorption mechanism of the imidazole ionic liquid on the surface of phosphorite and quartz was investigated by contact angle and zeta potential measurements, Fourier transform infrared and X-ray photoelectron spectroscopy analyses. These results showed that the adsorption of imidazole ionic liquid at the quartz surface was stronger than that of phosphorite, and the collector adsorbability difference between quartz and phosphorite resulted in the efficient flotation separation. Consequently, the dodecyl-tri-methylimidazolium chloride salt is an effective collector for reverse flotation of quartz from phosphorite.

4

Dolnokredowe fosforyty z NE obrzeżenia Gór Świętokrzyskichjako potencjalne źródło REE : badania wstępne

Zglinicki Karol, Szamałek Krzysztof, Salwa Sylwester, Górska Irena

Przegląd Geologiczny

|

2020

|

Vol. 68, nr 7

566--576

EN

The PGI-NRI conducts geological research on the documentation of occurrence of REE deposits in Poland. The deposit potential may be related to the formation of Lower Cretaceous phosphorites from the NE margin of the Holy Cross Mountains. Two phosphorite deposits were exploited in this region in the past: Chałupki (1936-1959) and Annopol (1952-1970). From the Chałupki old mine dump, 34 samples of fine-grained sand were collected. The pseudonodules were extracted from this sand. The sand from the dump is composed of quartz, francolite (carbonate-rich fluorapatite) Ca5(PO4,CO3)3F, illite and a small amount of feldspar, calcite and heavy minerals. The heavy fraction is composed of zircon, monazite and rutile. Sand has a low content of REE ranging from 47.56 to 185.26ppm. The phosphorite pseudonodules underwent a detailed mineralogical and chemical analysis. They are composed of francolite, quartz, illite, glauconite, feldspar and minor heavy minerals: zircon and monazite. For the first time, the whole spectrum of REE was analysed in pseudonodules. The I.REE content in the nodules ranges from 177.37 to 354.18ppm. This level of REE indicates a serious need for further exploration and research of phosphorite pseudonodules within the whole Lower Cretaceous phosphorite series and moreover, also in the Eocene phosphorite formation in the Lublin region.

5

Wpływ związków fosforu zawartych w osadach ściekowych na wzrost rzepaku

Pyrak M., Worwąg M.

Inżynieria i Ochrona Środowiska

|

2018

|

T. 21, nr 1

67--78

EN

Phosphorus is an element frequent in natural environment. It is necessary for the proper functioning of plants. Throughout the world are used phosphate fertilizers to improve soil quality in crop fields to create the best conditions for plant breeding. This fertilizers are produced from phosphate rock, whose high rate of exploitation may lead to depletion of natural phosphorus deposits over the next several decades. Therefore, there is an increasing interest in the effective use of waste containing large amounts of phosphorus compounds, which include sewage sludge. The main goal was to analyze the effect of the addition of phosphorus compounds contained in sewage sludge and mineral fertilizer on the growth and biomass of rapeseed Brassica napus L. ssp. napus. The essence of research was a 4-week, sterile culture of in vitro rapeseed on media prepared from soil extracts with the addition of mineral fertilizer and sewage sludge from “WARTA” wastewater treatment. At the end of breeding, a plant analysis was carried out in terms of the amount of seeds sprouted, length, weight and percentage of water content in above-ground parts and rapeseed roots. The obtained results indicate that sewage sludge, both in comparison to the control sample as well as the sample with mineral fertilizer, had a positive effect on the germination rate and overall plant growth. Compared sample with control sample, the aboveground parts in sample with addition of sewage sludge were longer on average 2.7 cm, they had a larger mass on average 0.1 g and it was better hydrated about 0.9%. Roots also were longer on average 9.4 cm and have larger mass on average 0.03 g.

PL

Fosfor jest pierwiastkiem biogennym niezbędnym do prawidłowego wzrostu roślin. Na całym świecie stosuje się nawozy fosforowe w celu polepszenia jakości gleby na polach uprawnych, aby stworzyć jak najlepsze warunki do hodowli roślin. Nawozy są wytwarzane z fosforytów, których wysokie tempo eksploatacji może doprowadzić do wyczerpania naturalnych złóż fosforu w ciągu najbliższych kilkudziesięciu lat. Dlatego wzrasta zainteresowanie w dziedzinie efektywnego wykorzystania odpadów o dużej zawartości związków fosforu, do których należą m.in. osady ściekowe. Celem pracy jest analiza wpływu dodatku związków fosforu zawartych w osadach ściekowych i nawozie mineralnym na wzrost i biomasę rzepaku Brassica napus L. ssp. napus. Istotę badań stanowi 4-tygodniowa, sterylna hodowla in vitro rzepaku na pożywkach sporządzonych z wyciągów glebowych z dodatkiem nawozu mineralnego oraz osadów ściekowych pochodzących z Oczyszczalni Ścieków „WARTA”. Po zakończeniu hodowli analizę roślin przeprowadzono pod względem liczby wykiełkowanych nasion, długości, masy oraz procentowej zawartości wody w częściach nadziemnych i korzeniach rzepaku. Z uzyskanych wyników wywnioskowano, że osady ściekowe, zarówno w porównaniu z próbą kontrolną, jak i z próbą z nawozem mineralnym, mają pozytywny wpływ na szybkość kiełkowania i ogólny rozwój roślin. W porównaniu z próbą kontrolną części nadziemne roślin są dłuższe o średnio 2,7 cm, posiadają większą o średnio 0,1 g masę oraz są lepiej uwodnione o ok. 0,9%. Korzenie również są dłuższe o średnio 9,4 cm oraz charakteryzują się zwiększoną masą o około 0,03 g.

6

Badania reaktywności fosforytów

Łuczkowska D., Kużdżał E., Cichy B.

Przemysł Chemiczny

|

2016

|

T. 95, nr 8

1538--1541

PL

Surowce fosforowe oceniono pod kątem właściwości morfologicznych, takich jak rozkład ziarnowy, współczynnik kształtu i powierzchnia właściwa BET. Wyznaczona reaktywność tych surowców w procesie wytwarzania ekstrakcyjnego kwasu fosforowego metodą dwuwodzianową jest wprost proporcjonalna do powierzchni właściwej cząstek poddawanych rozkładowi kwasem siarkowym, pomimo znacznych różnic w składzie chemicznym i rozkładzie ziarnowym.

EN

Seven phosphorites of Polish or Uzbekian origin were tested for morphol. properties (grain size distribution, shape factor, sp. surface), and studied for reactivity in the dihydrate variant of the wet process for H₃PO₄ manufg. where the phosphorite grains were decompd. with H₂SO₄. The relationship between their reactivity and sp. surface was directly proportional, despite the significant disparity in chem. compn. and in grain size distribution.

7

Improvement of the solubility of rock phosphate by co-composting it with organic components

Korzeniowska J., Stanisławska-Glubiak E., Hoffmann J., Górecka H., Jóźwiak W., Wiśniewska G.

Polish Journal of Chemical Technology

|

2013

|

Vol. 15, nr 4

10-14

EN

One possible way to improve the solubility of phosphate rock is by co-composting it with organic substances. Four variants of composts were made in a biomass composting bioreactor. Ground phosphate rock (GPR) and shredded barley straw, pine sawdust as well as beet pulp pellets were used as compost components. The four composts were different from one another in the type and amount of organic components. The composts were granulated in a pelleting press. Changes in the solubility of phosphorus were assessed via chemical analyses and P-recovery efficiency calculated from the data achieved in a pot experiment. Solubility of ground phosphate rock was increased resulting from co-composting with organic substances, which meant that bioavailability of phosphorus increased. All the tested composts were characterized by a higher ratio of ammonium citrate soluble phosphorus to total phosphorus than non-composted GPR. Co-composting GPR with all the tested organic components yielded better effects than composting it with straw alone. The four composts were characterized by a slow release of P, which justifies our expectation that they will produce residual effects in the years following their application.

8

Wpływ związków fluoru emitowanych przez zakłady fosforowe na zawartość fluoru w warzywach

Nowak W., Wróbel S.

Chemia i Inżynieria Ekologiczna

|

2002

|

Vol. 9, nr 10

1267--1274

PL

Zakłady chemiczne przetwarzające fosforyty emitują do środowiska związki fluoru zwiększające zawartość fluoru w glebie i roślinach. Toksyczność fluoru w środowisku jest kilkadziesiąt razy większa w porównaniu do ditlenku siarki. Podwyższona zawartość fluoru w spożywanych przez człowieka produktach roślinnych powoduje pobieranie tego składnika w nadmiernych ilościach, co odbija się niekorzystnie na zdrowiu. W latach 1995-2000 przeprowadzono badania zawartości fluoru w warzywach korzeniowych i liściowych, pobranych z ogrodów przydomowych miejscowości położonych w bezpośrednim sąsiedztwie Zakładów Chemicznych „Wizów” S.A. Zawartość fluoru oznaczano, stosując elektrodę jonoselektywną, po mineralizacji próbek na sucho w środowisku alkalicznym. Badaniami objęto głównie następujące gatunki warzyw: pietruszkę, marchew, burak ćwikłowy, kapustę, seler, sałatę i por. Stwierdzono, że zawartość fluoru w warzywach liściastych była z reguły 2-3 razy większa w porównaniu do zawartości w warzywach korzeniowych (marchew, pietruszka, burak ćwikłowy). Największą zawartością wyróżniały się liście sałaty i buraka ćwikłowego, w których koncentracja fluoru była niekiedy bliska 100 mg w 1 kg suchej masy. Ograniczenie emisji fluoru przez Zakłady wpływało wyraźnie na zmniejszenie jego zawartości w badanych warzywach, Przy czym zmiany te były znacznie większe w korzeniach niż w liściach. Duży wpływ na zawartość fluoru wywierał czas ekspozycji roślin na emisję fluoru. Świadczy to o pobieraniu tego składnika przez rośliny głównie z powietrza (formy gazowe i pyły zawierające fluor). Fluor w glebie natomiast przy odczynie zbliżonym do obojętnego nie jest pobierany przez rośliny, ponieważ znajduje się w formie niedostępnej.

EN

Processing phosphorites chemical works, emit fluorine compounds into environment thus increase fluorine concentration in soil and plants. Fluorine toxicity in the environment is a few dozen times higher to compare with that of sulphur dioxide. Increased fluorine content in plant products consumed by people causing excessive accumulation of the element in the human body posing a potential health hazard. In the years 1995-2000 a study on fluorine content in greens and root vegetables collected from the home gardens located in the neighborhood of Chemical Works „Wizów” Company Ltd, Bolesławiec was carried out. Determination of the fluorine content was made by means of ion-selective electrode after samples dry mineralization in alkaline medium. The following species of vegetables were analyzed: parsley, carrot, reed beet, cabbage, celery, lettuce and leek. It was stated that F concentration in vegetable tops were usually 2-3 times higher than in root vegetables (carrot, parsley, red beet). The highest fluorine concentration was found in the lettuce and red beet leaves (up to 100 mg F ּ kg-1 of dry matter). A decided influence of fluorine emission decreasing by Chemical Works on the element concentration in vegetables was noted. The changes observed were larger in roots than in plant tops. Emission exposure time exerted the significant influence on F concentration level in the plants. This indicates that fluorine was absorbed mainly from the atmosphere (gases and dusts containing F). Under near neutral soil reaction conditions fluorine is immobilized and unavailable to plant.