scholarly journals Experimental Study on Optimization of Phosphogypsum Suspension Decomposition Conditions under Double Catalysis

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1120
Author(s):  
Pinjing Xu ◽  
Hui Li ◽  
Yanxin Chen
Keyword(s):  
Thermal Decomposition ◽  
Decomposition Rate ◽  
Building Materials ◽  
Phosphate Fertilizer ◽  
Decomposition Reaction ◽  
Carbon Powder ◽  
Desulfurization Rate ◽  
Factors Affecting ◽  
Laboratory Conditions ◽  
Powder Content

Phosphogypsum (PG) is not only a solid waste discharged from the phosphate fertilizer industry, but also a valuable resource. After high-temperature heat treatment, it can be decomposed into SO2 and CaO; the former can be used to produce sulfuric acid, and the latter can be used as building materials. In this paper, the catalytic thermal decomposition conditions of phosphogypsum were optimized, and the effects of the reaction temperature, reaction atmosphere, reaction time and carbon powder content on the decomposition of phosphogypsum were studied. The research shows that the synergistic effect of carbon powder and CO reducing atmosphere can effectively reduce the decomposition temperature of phosphogypsum. According to the results of the orthogonal test under simulated suspended laboratory conditions, the factors affecting the decomposition rate of phosphogypsum are temperature, time, atmosphere and carbon powder content in turn, and the factors affecting the desulfurization rate are time, temperature, atmosphere and carbon powder content in turn. Under laboratory conditions, the highest decomposition rate and desulfurization rate of phosphogypsum are 97.73% and 97.2%, and the corresponding reaction conditions are as follows: calcination temperature is 1180 °C, calcination time is 15 min, carbon powder content is 4%, and CO concentration is 6%. The results of thermal analysis of phosphogypsum at different temperature rising rates show that the higher the temperature rising rate, the higher the initial temperature of decomposition reaction and the temperature of maximum thermal decomposition rate, but the increase in the temperature rising rate will not reduce the decomposition rate of phosphogypsum.

Reactivity of the first transition row metallocenes in thermal decomposition reaction

1979 ◽  
Vol 175 (1) ◽  
pp. 63-72 ◽  
Author(s):  
L.M. Dyagileva ◽  
V.P. Mar'in ◽  
E.I. Tsyganova ◽  
G.A. Razuvaev
Keyword(s):  
Thermal Decomposition ◽  
Decomposition Reaction

A large-scale test set-up for measuring VOC emissions from wood products under laboratory conditions in simulated real rooms

Holzforschung ◽  
2015 ◽  
Vol 69 (4) ◽  
pp. 457-462 ◽  
Author(s):  
Eva Höllbacher ◽  
Cornelia Rieder-Gradinger ◽  
Daniel Strateva ◽  
Ewald Srebotnik
Keyword(s):  
Large Scale ◽  
Building Materials ◽  
Wood Products ◽  
Test Set ◽  
Voc Emissions ◽  
Laboratory Conditions ◽  
Volatile Organic ◽  
Scale Test ◽  
Set Up ◽  
Realistic Data

Abstract A large-scale test set-up was designed to evaluate the volatile organic compound (VOC) emissions of building materials in a real room situation but under laboratory conditions. Two model rooms (ModR) with a volume of 30 m3 each were constructed of the wood-based building materials X-lam and OSB, respectively. Temperature and relative humidity (RH) inside the ModR were kept in a range of 21°C–25°C and 45%–55% RH. VOCs were collected at 13 different times over a period of 23 weeks, and the total VOC (TVOC) concentration was calculated from GC/MS data. Results were quantified as toluene equivalents (TE). In the X-lam-ModR, the TVOC concentration decreased by 64% over the whole measurement period from 115 to 41 μg m-3 TE. Terpenes were the most abundant substance group and accounted, on average, for 80% of the TVOC concentration. In the OSB-ModR, the TVOC concentration decreased by 72% from 443 to 124 μg m-3 TE. Aldehydes showed the highest concentrations, accounting, on average, for 52% of the TVOC, while 38% were terpenes. The results show that this type of test provides realistic data for the praxis.

Influence of Cadmium Oxide on Thermal Hazard of AP-CMDB Propellants

2015 ◽  
Vol 1095 ◽  
pp. 419-422 ◽  
Author(s):  
Hao Nan Jia ◽  
Gui E Lu ◽  
Zhen Tao An ◽  
Jin Yong Jiang ◽  
Qiang Ge ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Decomposition ◽  
Decomposition Rate ◽  
Initial Temperature ◽  
Cadmium Oxide ◽  
Thermal Hazard ◽  
Test Results ◽  
Thermal Safety ◽  
Scanning Calorimetry ◽  
Two Stages

The influence of cadmium oxide on the thermal decomposition behaviors of AP-CMDB propellants was studied by differential scanning calorimetry (DSC) and accelerating rate calorimetry (ARC). The test results show that the decomposition process of AP-CMDB can be divided into two stages. Cadmium oxide can increase the initial temperature, slow down the decomposition rate and improve the thermal safety of AP-CMDB.

Some local factors affecting iridic lipid infiltration in hypercholesteremic rabbits

1959 ◽  
Vol 197 (4) ◽  
pp. 842-846 ◽  
Author(s):  
Meyer Friedman ◽  
Sanford O. Byers
Keyword(s):  
Cottonseed Oil ◽  
Aortic Tissue ◽  
Factors Affecting ◽  
Experimental Animals ◽  
Local Factors ◽  
Laboratory Conditions ◽  
Intermittent Exposure ◽  
Intense Light

The influence of various factors affecting the deposition of lipid and cholesterol in the iris of rabbits fed cholesterol and cottonseed oil was studied. It was observéd that this deposition could be increased by the intraocular implantation of either normal aortic tissue or polyethylene discs. In an additional study, it was found that intermittent exposure of the eyes of cholesterol-fed rabbits to intense light also provoked an earlier and more intense iris deposition of lipid and cholesterol than was observed in the eyes of similarly fed rabbits kept either in absolute darkness or under ordinary laboratory conditions. It was postulated that the factor responsible for the greater iridic deposition observed in all these experimental animals was the iridic vasodilatation effected by these experimental measures.

scholarly journals Improvement in Carbonization Efficiency of Cellulosic Fibres Using Silylated Acetylene and Alkoxysilanes

Fibers ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 84
Author(s):  
Maria Mironova ◽  
Igor Makarov ◽  
Lyudmila Golova ◽  
Markel Vinogradov ◽  
Georgy Shandryuk ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Thermal Behavior ◽  
Comparative Studies ◽  
Decomposition Reaction ◽  
Activation Energies ◽  
Composite Fibers ◽  
Carbon Yield ◽  
Pyrolysis Reaction ◽  
Cellulosic Fibres

Comparative studies of the structure and thermal behavior of cellulose and composite precursors with additives of silyl-substituted acetylene and alkoxysilanes were carried out. It is shown that the introduction of silicon-containing additives into the cellulose matrix influenced the thermal behavior of the composite fibers and the carbon yield after carbonization. Comparison of the activation energies of the thermal decomposition reaction renders it possible to determine the type of additive and its concentration, which reduces the energy necessary for pyrolysis. It is shown that the C/O ratio in the additive and the presence of the Si–C bond affected the activation energy and the temperature of the beginning and the end of the pyrolysis reaction.

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