Abstract Evolved gas analyses of model inorganic compounds and apatites are described. The measurements are performed on the system – a `thermochromatograph' (ThGC) – with a low-volume, thermal furnace, interfaced to a capillary gaschromatograph (GC) via a computer-controlled, pneumatic sampleinlet device in the 70–600°C region. The `information content' performance of this inherently simpler system is
[EN] PROCESS FOR RECOVERING PHOSPHORIC ACID FROM SOLID PHOSPHORUS SOURCES<br/>[FR] PROCÉDÉ DE RÉCUPÉRATION D'ACIDE PHOSPHORIQUE PROVENANT DE SOURCES DE PHOSPHORE SOLIDES
申请人:UNIV AMSTERDAM
公开号:WO2020169708A1
公开(公告)日:2020-08-27
The invention pertains to a process for preparing phosphoric acid from a solid phosphorus-containing material, comprising the steps of: - reacting a solid phosphorus-containing material with strong acid in an amount of 1.0-15 mole acid, calculated as protons, per mole of phosphorus (calculated as P) in the solid phosphorus-containing material in a monophasic reaction medium comprising an organic solvent, to form a solution of phosphoric acid in organic solvent and remaining solid material, - separating the solution of phosphoric acid in organic solvent from the remaining solid material. It has been found that phosphoric acid can be recovered from a solid phosphorus-containing material in high purity and efficiency via a solid-state rearrangement/elution process. The process according to the invention does not require the use of the large amounts of water required by the conventional dissolution/extraction processes known in the art. The solution of phosphoric acid in organic solvent can be used as a starting material for further processes.
Phase changes on heating ammonium magnesium phosphate hydrates
作者:B.E.I. Abdelrazig、J.H. Sharp
DOI:10.1016/0040-6031(88)87336-2
日期:1988.7
paths, dependent on the combination of phases present and the experimental variables, especially the atmosphere. By heating samples to various temperatures, quenching to room temperature and examining the reaction products by X-ray diffraction, the phases formed after various heat treatments have been identified. The most important reaction sequence on heating in the presence of excess MgO is
Hydration/dehydration characteristics of struvite and dittmarite pertaining to magnesium ammonium phosphate cement systems
作者:A. K. Sarkar
DOI:10.1007/bf01130204
日期:——
Struvite, an important reaction product in magnesiumammoniumphosphate cement systems, was synthesized in the laboratory. The elevated-temperature dehydration and then roomtemperature hydration characteristics of the dehydrated products were studied by thermogravimetric analyses and X-ray diffraction techniques. From isothermal experiments, struvite is found to be thermally unstable in air at temperatures
鸟粪石是磷酸铵镁水泥体系中的重要反应产物,是在实验室中合成的。通过热重分析和X射线衍射技术研究了脱水产物的高温脱水和室温水合特性。从等温实验中,发现鸟粪石在空气中温度高于 50 ‡C 时是热不稳定的。根据热处理的时间和温度,鸟粪石可以失去部分或全部的氨和水分子,最终形成磷酸氢镁。这种分解的产物是 X 射线无定形的,在室温再水合后可以单独或相互组合形成鸟粪石、未知水合物或新辉石,具体取决于结构中残留的氨量。然而,当鸟粪石在过量的水中加热时,它只会失去结晶水,形成一水合物,dittmarite。Dittmarite 比鸟粪石更热稳定,并且与鸟粪石一样,分解时也会形成磷酸氢镁。在室温和过量水的存在下,dittmarite 可以缓慢转变为六水合物鸟粪石。描述了鸟粪石和白铁矿之间结构相似性的结果以及它们可能存在于固化水泥中的条件。
Chemical control of struvite scale by a green inhibitor polyaspartic acid
作者:Han Li、Sheng-Hui Yu、Qi-Zhi Yao、Gen-Tao Zhou、Sheng-Quan Fu
DOI:10.1039/c5ra17149k
日期:——
Many efforts have been made to develop effective chemical inhibitors for struvite scale, which causes a range of operational problems in the wastewater treatment industry. Herein, the inhibitory capacity of polyaspartic acid (PASP) on the spontaneous precipitation of struvite at pH 9 was investigated. Struvite precipitates were characterized using X-ray diffraction (XRD), field emission scanning electron