The performance characteristics and growth mechanism of CSW were reviewed in this paper.The preparation methods of CSW,hydrothermal synthesis and atmospheric acidification method were also introduced,especially the influence of preparation process on the growth of CSW by hydrothermal synthesis was detailed.The pretreatment method …
Flue-gas desulphurization (FGD) gypsum is a highly prevalent industrial by-product worldwide, which can be an excellent alternative to natural gypsum due to its high content of CaSO4·2H2O. The preparation of α-calcium sulfate hemihydrate is a high-value pathway for the efficient use of FGD gypsum. Here, a dynamic method, or an improved …
The present invention relates to a process for producing sodium sulphate from phosphogypsum, comprising: a step (101) of lixiviation of phosphogypsum by means of a basic solution so as to obtain a sodium sulphate solution (S) containing metal impurities, said basic solution comprising a chelating agent suitable for forming complexes with at …
Phosphogypsum (PG) is a by-product produced during the wet process of phosphoric acid (H3PO4) production from natural phosphate rocks. Approximately 4–6 tons of PG is produced per ton of phosphoric acid production, where worldwide PG generation exceeds 300 million tons annually. The vast majority of produced PG is discarded …
The present work suggests an attractive process allowing total PG conversion by potassium hydroxide KOH. This decomposition leads to potassium …
DOI: 10.1016/j.conbuildmat.2024.134888 Corpus ID: 266829335; Preparation of α-hemihydrate gypsum whiskers from phosphogypsum using atmospheric pressure nitrate solution @article{Xia2024PreparationO, title={Preparation of $alpha$-hemihydrate gypsum whiskers from phosphogypsum using atmospheric pressure …
[20−24] Table 1 Main technology of phosphogypsum preparation of β-hemihydrate gypsum [20−24] [25,26] [31] 。 ... The aim of this process is to produce potassium sulfate, a high-value ...
Phosphogypsum (PG) is an industrial by-product of the transformation of phosphate rocks. For decades, PG has been a source of environmental concern due to the massive amount produced thus far, i.e., 7 billion tons, with a current production rate of 200–280 million tons per year. Phosphate minerals contain various impurities that …
The process conditions for two-step conversion of phosphogypsum to make K2SO4 are obtained from single factor experiment: The optimal experimental condition for the first-step reaction is reaction temperature 35 ℃, reaction duration approximately more than 90 min, n( Ca SO4) /n( 2NH4HCO3) is 0. 9,where the phosphogypsum conversion η( SO2-4) is …
The process of potassium sulfate crystallization from aqueous solutions in the presence of organic modifiers containing phosphonic, phosphate, sulfonic, sulfate and carboxyl functional groups has ...
Phosphogypsum (PG), commonly known as calcium sulfate, is a waste by-product generated during the production of phosphoric acid by the wet phosphoric acid process (WPA). It is well known that every year the phosphate industries produce a large quantity of PG around the world (i.e., Currently, global production of this waste is …
The preparation technology of α-HH includes autoclave method, pressurized hydrothermal method and atmospheric hydrothermal method. The autoclave method was first used in industrial production of α-HH, but this method needs high temperature, high-pressure apparatus and high-energy consumption, it is difficult to …
Analytical grade glycerol (C 3 H 8 O 3), sodium sulfate (Na 2 SO 4) and citric acid (C 6 H 8 O 7 ·H 2 O) were purchased from Tianjin Zhiyuan Chemical Reagent Co., Ltd., China. PG was collected from a phosphate fertilizer plant in Guizhou Province, China. The X-ray diffraction (XRD) (X'Pert PRO, PANalytical Company, Netherlands) …
The process conditions for two-step conversion of phosphogypsum to make K2SO4 are obtained from single factor experiment: The optimal experimental condition for the first …
The aim of this process is to produce potassium sulfate, a high-value fertilizer, from sulfate solutions obtained after dissolving Moroccan phosphogypsum in NaOH medium.
The main mineral phase of the raw phosphogypsum was characterized by X-ray diffraction analysis. As shown in Fig. 2 b, the XRD results confirmed that the mainly composed of phosphogypsum is calcium sulfate CaSO 4 ·2H 2 O The major peaks of CaSO 4 was identified at 11.71°, 20.80°, 23.44° and 29.16°, while some minor peaks …
A sustainable approach for the production of high purity potassium fertilizer (K2SO4) is highly needed to cope with the food crisis.
In this present work, the transformation of the Moroccan phosphogypsum (PG) waste, considered a potential source of sulfate, into potassium sulfate compound could help reduce environmental impact and create a new value chain for the phosphate industry. Generally, solid–liquid equilibria are frequently applied in chemical industries. …
Phosphogypsum. Phosphogypsum is the primary waste byproduct of the wet-acid process for producing phosphoric acid. During this process sulfuric acid dissolves phosphate rock creating a solid/liquid mixture (slurry) of phosphoric acid and calcium sulfate (phosphogypsum).
BAOGUO MA, ZIHAO JIN, YING SU, et al. Utilization of hemihydrate phosphogypsum for the preparation of porous sound absorbing material[J]. Construction and Building Materials, 2020(234):1177346. Google Scholar ... Two - step process for potassium sulfate production from phosphogypsum.
A substantial stockpile of phosphogypsum (PG) not just consumes land resources, but also poses environmental contamination risks. Herein, the conversion of PG into high-value α-hemihydrate gypsum (α-HH) whisker by the atmospheric pressure salt solution method with simple process, high efficiency and low energy consumption was …
Phosphogypsum (PG), consisting of calcium sulfate dihydrate and some impurities (sulfuric acid, phosphoric acid, phosphide, fluoride, and organic matter), is a solid waste from the wet phosphoric ...
The factors affecting the conversion of potassium chloride to potassium sulfate, such as aqueous ammonia to phosphogypsum ratio, weight percent of isopropanol in the solution, weight percent excess phosphogypsum, and reaction temperature and pressure have also been investigated.The optimum reaction conditions obtained at 25°C and atmospheric ...
The aim of this process is to produce potassium sulfate, a high-value fertilizer, from sulfate solutions obtained after dissolving …
The aim of this process is to produce potassium sulfate, a high-value fertilizer, from sulfate solutions obtained after dissolving Moroccan phosphogypsum in NaOH medium.
Sustainable process for the preparation of potassium sulfate by electrodialysis and its concentration and purification by a nanofiltration process. ... The production of potassium sulfate from phosphogypsum and potassium chloride in the presence of ammonia and isopropanol has been investigated. The solubility of phosphogypsum in aqueous ...
As both CaHPO 4 ·2H 2 O and CaSO 4 ·2H 2 O belong to monoclinic crystal system and possess comparable lattice constants, HPO 4 2− can easily replace part of SO 4 2− during the production of wet-process phosphoric acid and enter the calcium sulfate lattice, thus forming eutectic phosphorus. By comparing the FTIR spectra of PG raw …
The process comprises four basic units: preparation of the ore and flotation, production of ite and its recovery, leaching of the ... In this production process, potassium sulfate is ...
To improve the process of potassium sulphate prepared from phosphogypsum (under study, no product, only method) in ammonia solution, the influence of solvent such as Methanol, Methanol-ammonia on the yield of potassium …
To improve the process of potassium sulphate prepared from phosphogypsum (under study, no product, only method) in ammonia solution, the influence of solvent such as Methanol, Methanol-ammonia on the yield of potassium oxide was studied. The result revealed that the system of ethanol and ammonia was optimal. …
The production of potassium sulfate from phosphogypsum and potassium chloride in the presence of ammonia and isopropanol has been investigated. …
