Preparation and Properties of Porous Mullite Refractory Aggregates Prepared Using Coal Gangue as Starting Material

2015 ◽  
Vol 64 (3) ◽  
pp. 94-99
Author(s):  
Jingjing Liu ◽  
Y. Li ◽  
B. Duan ◽  
S. Li ◽  
Y. Li ◽  
...  
2013 ◽  
Vol 815 ◽  
pp. 886-892
Author(s):  
Feng Duan ◽  
Ai Qiong Ma ◽  
Guo Qing Xiao ◽  
Xiao Hui Zhang ◽  
Ren Hong Yu

nfluencing factors of target products such as X phase, β-SiAlON phase and O-SiAlON phase of Inner Mongolia coal gangue carbothermal reduction and nitridation were researched by calculating the loss rate on ignition of specimens, and by means of XRD and SEM. During the carbothermal reduction and nitridation reaction of coal gangue, the loss rate on ignition of specimens rises with carbon reducer increasing, and keeping time has a little influence on the loss rate on ignition of specimens. If β-SiAlON is target phase, the yield from corundum is much higher than that from special grade bauxite. Corundum or bauxite is used as starting material, the yield of X phase is low and the highest yield is only 12.88%. For the carbothermal reduction and nitridation reaction of coal gangue, the appropriate addition of reducer carbon is 10%-16%, and temperature influence is larger. The reaction temperature over 1420°C and keeping time of 6h are beneficial to the formation of X phase, β-SiAlON and O-SiAlON.


2017 ◽  
Vol 53 (2) ◽  
pp. 287-291 ◽  
Author(s):  
Zhang Wang ◽  
Peizhong Feng ◽  
Peng Geng ◽  
Cheng Xu ◽  
Farid Akhtar

Author(s):  
I.A. Petukhova ◽  
V.K. Riabchun ◽  
V.A. Muzapharova ◽  
O.I. Padalka ◽  
T.A. Sheliakina ◽  
...  

The goal of our research was to form a collection of groats barley, to search, to select and to evaluate starting material of spring barley for a set of valuable economic traits, technological properties and culinary qualities of barley groats. Results and Discussion. Basing on to the results of assessments, we identified selected 55 spring barley accessions, which were characterized by 17 traits and 75 expression levels. The collection includes accessions from 11 countries; the largest number of accessions (59) are from Ukraine; 39 – from Russia; 10 - from Belarus; 10 - from Germany; 6 - from France; 5 - from Kazakhstan; 4 - from Canada; 3 - from the Czech Republic; 2 – from Great Britain; 1 accesson is from Serbia; and 1 - from Austria. Accessions combining high levels of expression of different traits are the most valuable. They include the following accessions: Doridnyi, Vodohrai, Sviatomykhailivskyi, Svarozhych, Soka, Іlot (UKR). Naked accessions include: Akhilles (UKR), Mayskiy, Oskar, Golozyornyy 1, Omskiy Golozyornyy 1 (RUS), CDC Alamo, CDC Candle (CAN). These varieties can be starting material for creation of new modern high-performance spring groats barley varieties. Ten valuable accessions registered with the NCPGRU (Sovіra, Doridnyi, Soka, Vodohrai, Partner, Yukatan, Avhii, Svarozhych, Baskak, and Virtuoz) were included in the trait groats collection. Conclusions. Basing on the results of multiyear studies, we formed the trait collection of spring groats barley comprising 140 accessions from 11 countries. The collection includes 55 reference accessions that cover 17 traits (plant height, vegetation period, ear length, grain weight per ear, 1000-grain weight, grain shape, grain evenness, vitreousness, culinary qualities of barley groats, etc.) characterized by 75 levels of their expression. The collection is of considerable value for science and education. The accessions selected allow improving the efficiency of breeding to create new varieties with high technological and culinary properties as well as with a set of valuable economic characteristics.


2020 ◽  
Vol 27 ◽  
Author(s):  
Joana Santos ◽  
M. Fernanda Proença ◽  
Ana Joao Rodrigues ◽  
Patricia Patrício ◽  
H. Sofia Domingues

: Paroxetine is a potent inhibitor of serotonin reuptake and is widely prescribed for the treatment of depression and other neurological disorders. The synthesis of paroxetine and the possibility to prepare derivatives with a specific substitution pattern that may allow their use as biological probes, is an attractive topic especially for medicinal chemists engaged in neurosciences research. Considering the extensive work that was developed in the last decade on the total synthesis of paroxetine, this review summarizes the most important contributions in this field, organized according to the reagent that was used as starting material. Most of the methods allowed to prepare paroxetine in 4-9 steps with an overall yield of 9-66%. Despite the progress made in this area, there is still room for improvement, searching for new eco-friendly and sustainable synthetic alternatives.


2014 ◽  
Vol 18 (4) ◽  
pp. 446-458 ◽  
Author(s):  
Daniel Strub ◽  
Lucyna Balcerzak ◽  
Stanislaw Lochynski

2020 ◽  
Vol 17 ◽  
Author(s):  
Duc Dau Xuan

: The synthesis of the A-B bicyclic ring structure 3 of the natural product Stemocurtisine is described. The synthesis was accomplished in seven synthetic steps from commercially available L-glutamic acid. The key step involved a borono-Mannich reaction between the hemiaminal 6 and trans-β-styryl boronic acid and trans-β-styrylpotassiumtrifluoroborate to prepare the cis diene 4. Attempts to prepare the A-B-C ring compound 2 via intramolecular epoxide ring opening followed by rearangement under different basic conditions were unsuccessful. Only unreactive starting material was recovered.


Author(s):  
Jiwei Zhang ◽  
Jingjing Xu ◽  
Shuaixia Liu ◽  
Baoxiang Gu ◽  
Feng Chen ◽  
...  

Background: Coal gangue was used as a catalyst in heterogeneous Fenton process for the degradation of azo dye and phenol. The influencing factors, such as solution pH gangue concentration and hydrogen peroxide dosage were investigated, and the reaction mechanism between coal gangue and hydrogen peroxide was also discussed. Methods: Experimental results showed that coal gangue has the ability to activate hydrogen peroxide to degrade environmental pollutants in aqueous solution. Under optimal conditions, after 60 minutes of treatment, more than 90.57% of reactive red dye was removed, and the removal efficiency of Chemical Oxygen Demand (COD) up to 72.83%. Results: Both hydroxyl radical and superoxide radical anion participated in the degradation of organic pollutant but hydroxyl radical predominated. Stability tests for coal gangue were also carried out via the continuous degradation experiment and ion leakage analysis. After five times continuous degradation, dye removal rate decreased slightly and the leached Fe was still at very low level (2.24-3.02 mg L-1). The results of Scanning Electron Microscope (SEM), energy dispersive X-Ray Spectrometer (EDS) and X-Ray Powder Diffraction (XRD) indicated that coal gangue catalyst is stable after five times continuous reuse. Conclusion: The progress in this research suggested that coal gangue is a potential nature catalyst for the efficient degradation of organic pollutant in water and wastewater via the Fenton reaction.


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