scholarly journals Investigation of the possibilities of phosphogypsum application for building partitioning Walls - elements of a prefabricated house

2002 ◽  
pp. 71-92 ◽  
Author(s):  
Milos Rajkovic ◽  
Dragan Toskovic
Keyword(s):  
Heavy Metal ◽  
Phosphoric Acid ◽  
Sulphuric Acid ◽  
Building Materials ◽  
Economic Effect ◽  
Waste Product ◽  
Substantial Saving ◽  
Wet Process ◽  
Crystal Composition ◽  
Partition Walls

Phosphogypsum is a waste product in the manufacture of phosphoric acid from phosphorite and sulphuric acid by so-called "wet process" and represents a refuse that is as such simply thrown away. Phosphogypsum which is produced by "dihydrating procedure" contains not only various impurties but also radionuclides, which limits its construction use. Performed testings point to the complexity of phosphogypsum structure and composition while the electron microscope's pictures showed its different crystal composition compared to the natural gypsum. The calcined and refined phosphogypsum can be used for partition walls manufacture. To avoid the danger of the possible presence of radionuclides it is better to use the mixture of natural gypsum and phosphogypsum for this purpose. Substantial saving of materials and economic effect can be achieved in this way. The analyse performed in this work have shown significant presence of radionuclides in phosphogypsum. Gammaspectrometric measurements of radioactivity have determined substantial radioactivity of phosphogypsum. Using the maximum tolerated level values that are legally accepted, as well as equations to calculate indexes of tolerated radionuclide presence, an index of 2.23 has been determined for interiors and 1.13 for exteriors, i.e. 0.64 in case of roads. On the basis of the maximum tolerated level of radioactive building materials contamination (< 1), forbiden is the use of phosphogypsum in interiors, allowed (? 1) in exteriors and roads. The tests of heavy metal components in phosphogypsum have proved their presence in the amounts potentially producing consequences if present in closed spaces. That is conditioned by the phosphogypsum quantity, as well as by the area of space partitioned.

scholarly journals Natural Building Materials for Interior Fitting and Refurbishment—What about Indoor Emissions?

Materials ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 234
Author(s):  
Matthias Richter ◽  
Wolfgang Horn ◽  
Elevtheria Juritsch ◽  
Andrea Klinge ◽  
Leon Radeljic ◽  
...  
Keyword(s):  
Building Materials ◽  
Negative Impact ◽  
Well Being ◽  
Testing Time ◽  
Evaluation Scheme ◽  
Partition Walls ◽  
Health Related ◽  
Internal Partition ◽  
Multiple Materials ◽  
Natural Building

Indoor air quality can be adversely affected by emissions from building materials, consequently having a negative impact on human health and well-being. In this study, more than 30 natural building materials (earth dry boards and plasters, bio-based insulation materials, and boards made of wood, flax, reed, straw, etc.) used for interior works were investigated as to their emissions of (semi-)volatile organic compounds ((S)VOC), formaldehyde, and radon. The study focused on the emissions from complete wall build-ups as they can be used for internal partition walls and the internal insulation of external walls. Test chambers were designed, allowing the compounds to release only from the surface of the material facing indoors under testing parameters that were chosen to simulate model room conditions. The emission test results were evaluated using the AgBB evaluation scheme, a procedure for the health-related evaluation of construction products and currently applied for the approval of specific groups of building materials in Germany. Seventeen out of 19 sample build-ups tested in this study would have passed this scheme since they generally proved to be low-emitting and although the combined emissions of multiple materials were tested, 50% of the measurements could be terminated before half of the total testing time.

Flame Photometric Determination of Calcium in Wet-Process Phosphoric Acid

1954 ◽  
Vol 26 (6) ◽  
pp. 1060-1061 ◽  
Author(s):  
J. A. Brabson ◽  
W. D. Wilhide
Keyword(s):  
Phosphoric Acid ◽  
Photometric Determination ◽  
Wet Process

A review of waste-containing building materials: Characterization of the heavy metal

2021 ◽  
Vol 309 ◽  
pp. 125107
Author(s):  
Zongxian Huang ◽  
Kuisheng Liu ◽  
Jinsong Duan ◽  
Qiang Wang
Keyword(s):  
Heavy Metal ◽  
Building Materials ◽  
Materials Characterization

scholarly journals Extraction of Nitric Acid from Wet-process Phosphoric Acid

2013 ◽  
Vol 20 (0) ◽  
pp. 183-195 ◽  
Author(s):  
Xuhong JIA ◽  
Jun LI ◽  
Yang JIN ◽  
Jianhong LUO ◽  
Baoming WANG ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Phosphoric Acid ◽  
Wet Process

Water–Phosphorus Nexus for Wet-Process Phosphoric Acid Production

2018 ◽  
Vol 57 (20) ◽  
pp. 6968-6979
Author(s):  
Hang Ma ◽  
Xiao Feng ◽  
Chun Deng
Keyword(s):  
Phosphoric Acid ◽  
Acid Production ◽  
Wet Process

Performance Study of Nonionic Filter Aid on Wet-Process Phosphoric Acid

2013 ◽  
Vol 781-784 ◽  
pp. 560-566
Author(s):  
Jie Xu ◽  
De Jun Fei ◽  
Jian Xun Wu ◽  
Ya Gu Dang
Keyword(s):  
Phosphoric Acid ◽  
Vacuum Filter ◽  
Performance Study ◽  
Application Performance ◽  
Wet Process ◽  
Surface Contact Angle ◽  
Void Area ◽  
Cake Porosity ◽  
Ionic Copolymer ◽  
Filter Aid

A non-ionic copolymer PAMA which has two functions of flocculation and surface activity was synthesized in aqueous solution. The copolymer was also characterized by means of infrared spectroscopic and unclear magnetic. The application performance of PAMA were studied, and the results show that the filtration rate of the phosphoric acid can be increased by about 3.8 times,the water content of the filter cake can be reduced by about 9.8%. Meanwhile, PAMA may increase the cake porosity by 25.82%,increase the mean void area about 7 times ,increase the surface contact angle of phophogypsum by 9.8°and decrease the surface tension by 7.4 mN·m-1 according to the SEM photos and hydrophobic experiment. All this confirms that PAMA is useful for vacuum filter system of wet process phosphoric acid.

scholarly journals Sorption Extraction of Rare Earth Metals from Wet-Process Phosphoric Acid

2021 ◽  
Vol 83 (1) ◽  
pp. 140-152
Author(s):  
Baltabekova Zhazira ◽  
Kenzhaliyev Bagdaulet ◽  
Lokhova Nina ◽  
Kassymzhanov Kaisar
Keyword(s):  
Rare Earth ◽  
Phosphoric Acid ◽  
Treatment Process ◽  
Cation Exchanger ◽  
Rare Earth Metals ◽  
Ion Exchangers ◽  
Technological Parameters ◽  
Complex Composition ◽  
Impurity Composition ◽  
Wet Process

When apatites and phosphorites are processed, up to 30% of rare earth metals are converted into wet-process phosphoric acid. Wet-process phosphoric acid from the phosphorite treatment process differs from apatite one by impurity composition, i.e. the iron content is by 3.5 times, and calcium is by 5.0 times more. The complex composition of the wet-process phosphoric acid from the phosphorite treatment process requires additional researches to select optimal ion exchangers and technological parameters of sorption. Various aspects of sorption have been studied to select the optimal ion exchangers and technological parameters, and technological modes for desorption of rare earth metals from a cation exchanger to obtain a concentrate of rare earth metals have been completed. The method enables to extract rare earth metals without changing the composition of commercial wet-process phosphoric acid directly in the production process of the enterprises engaged in the phosphorite treatment process.

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