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Reagents for Water Treatment
Published in Willy J. Masschelein, Unit Processes in Drinking Water Treatment, 2020
Contact of phosphoric acid with skin and eyes can cause irritation and burning. Respiration of vapors must be avoided, as it can cause damage to the upper respiratory system. The maximum allowable concentration in a working area is 1 mg/m3. On mixing with concentrated alkali, explosions can result. Rinsing and cleansing with water are recommended. Lung intoxication requires medical assistance.
Phosphatic Resources: A Valuable Wealth of Rare Earths
Published in Abhilash, Ata Akcil, Critical and Rare Earth Elements, 2019
Dhruva Kumar Singh, Vivekanand Kain
The phosphate rock after beneficiation is subjected for acidulation to obtain the phosphoric acid with mineral acids such as HCl, H2SO4, and HNO3 depending upon the requirement by fertilizer companies [24–28]. Mostly, digestion of phosphate rocks by sulfuric acid is practiced to produce phosphoric acid [9,13]. The overall and simplified reaction between calcium phosphate minerals and sulfuric acid can be written as
Nonparametric Statistics
Published in William M. Mendenhall, Terry L. Sincich, Statistics for Engineering and the Sciences, 2016
William M. Mendenhall, Terry L. Sincich
Reactivity of phosphate rock. Phosphoric acid is chemically produced by reacting phosphate rock with sulfuric acid. An important consideration in the chemical process is the length of time required for the chemical reaction to reach a specified temperature. The shorter the length of time, the higher the reactivity of the phosphate rock. An experiment was conducted to compare the reactivity of phosphate rock mined in north, central, and south Florida. Rock samples were collected from each location and placed in vacuum bottles with a 56% strength sulfuric acid solution. The time (in seconds) for the chemical reaction to reach 200°F was recorded for each sample. Do the data (shown below) provide sufficient evidence to indicate a difference in the reactivity of phosphoric rock mined at the three locations? Test using α = .05.
Rheological behaviour modelling of phosphoric acid produced from Moroccan phosphate rocks
Published in Indian Chemical Engineer, 2023
A. Boukhsib, L. Khamar, M. S. Kadiri, K. Khallaki, L. Omari
Industrial phosphoric acid (PA) is produced essentially from the wet attack of phosphate rock by a mineral acid, notably concentrated sulfuric acid (H2SO4) [1]. It is the main intermediate raw material for the manufacture of phosphate-based fertilisers and other derived products [2]. The production of phosphoric acid according to the wet process dihydrate consists on attacking the phosphate rock with sulfuric acid. The phosphoric slurry produced from this reactional mechanism is filtered in order to separate phospho-gypsum (solid phase) from phosphoric acid. A portion of this filtered acid, with a concentration of 18% P2O5, is recycled to the phosphate attack reactor, as the main reagent. The PA produced at this stage, with a phosphorus pentoxide’s concentration of 29%P2O5, is concentrated further by a vacuum flash separation in order to produce a commercial phosphoric acid at 54%P2O5. Generally, in many fertiliser processes, these two profiles of phosphoric acid, ACP 29%P2O5 and ACP 54%P2O5, are mixed with ponderation to produce PA at 42%P2O5 concentration, which is used in fertiliser production [1,3].
Effects of Cr content on the corrosion behaviour of porous Ni–Cr–Mo–Cu alloys
Published in Corrosion Engineering, Science and Technology, 2021
Xide Li, Junsheng Yang, Yangdon Hu, Haoran Zou, Chuo Zhang, Yuzuo Liu, Lieqiang Xiong, Jianping Ye
Phosphoric acid is an important inorganic chemical, which is used primarily in the pharmaceutical, food [1], fertiliser [2] and other industries. Currently, wet-process phosphoric acid technology occupies a leading position in phosphoric acid production due to its low energy consumption [3,4]. However, various strong corrosive acids and inorganic salt are involved in the manufacturing process, such as high concentration of phosphoric acid, sulphuric acid, low concentrations of hydrofluoric acid and calcium sulfate precipitation [5]. In order to obtain higher phosphoric acid concentrations, a solid–liquid separation is performed by filtration. The traditional treatment process is still heavily dependent upon settling tank and flocculation tank. The shortcomings of this process are large area, a long settling time, low settling efficiency and low product purity, which increase the production costs and affect working efficiency. Therefore, it is urgent to design innovative technology and materials for procuring refined phosphoric acid.
Residence time distribution studies using radiotracers in chemical industry—A review
Published in Chemical Engineering Communications, 2018
Meenakshi Sheoran, Avinash Chandra, Haripada Bhunia, Pramod K. Bajpai, Harish J. Pant
The phosphoric acid is used in the production of phosphate fertilizer (Table 4). The investigation of phosphoric acid production plant has been perfomed using Technetium (99mTc) as radiotracer by Abdelouahed and Reguigui (2011). The radiotracer 99mTc and 131I were used to trace the process material. Also, the safety aspects related to the radioactive material, injection protocol, detection system, and advantages of radiotracer were described in this paper. Perfect mixers in parallel and perfect mixers in recycle models were used to describe the dynamics of the process (Abdelouahed et al., 2016).