A facile approach for large-scale recovery of phosphogypsum: An insight
Phosphogypsum (PG), industrial solid waste, is generated from phosphoric acid production [1], [2]. In China, approximately 75 Mts of PG were discharged in 2019, and the stockpile is estimated to exceed 400 Mts [3]. ... Among common pretreatments, washing can remove harmful impurities, including soluble phosphorus, soluble fluorides, organic ...
The Generation Process, Impurity Removal and High-Value …
Among the methods of physical decontamination, washing is the most effective. Washing can remove most of the soluble impurities, but in terms of the environment, the sewage after washing must be treated before discharge or reuse, otherwise it will cause secondary pollution.
Efficient removal of phosphate impurities in waste phosphogypsum …
The storage of phosphogypsum could bring huge burden to the environment, while the traditional method of washing and purifying phosphogypsum produced a large amount of waste water and colossal ...
Flotation purification of waste high-silica phosphogypsum
The physical methods are based on particle size separation mainly including sieving and washing (Andrade Neto et al., 2021; Potgieter et al., 2003). The thermal method can remove organic matter from phosphogypsum and obtain hemihydrate or anhydrous gypsum using high-temperature calcination (Taher, 2007).
A facile approach for large-scale recovery of …
Among common pretreatments, washing can remove harmful impurities, including soluble phosphorus, soluble fluorides, organic matter, and residual acid, which can significantly …
High-Efficiency Purification and Morphology Regulation of …
The current impurity removal methods include: (1) water washing can remove the acidic and soluble impurities of phosphogypsum, but it is difficult to remove insoluble impurities, and the …
Recycling phosphogypsum in road construction materials …
Water washing and flotation methods are commonly used to purify PG. The water washing method can remove most impurities. However, the wastewater after washing must be treated properly to prevent secondary contamination. Flotation is not as effective as water washing, but the water can be reused, making it more environmentally friendly.
A Novel Process to Recover Gypsum from Phosphogypsum
Figure 11a–d shows further that the phosphogypsum, after grading and flotation of the gypsum concentrate, dispersed and had a smooth crystal surface, which indicates that the phosphogypsum through classification of pre-treatment using direct flotation can effectively remove impurities in the phosphogypsum concentrate, thus significantly ...
Removing clay and impurities from phosphogypsum | LZZG
The physical methods for pretreatment of phosphogypsum include water washing, flotation, ball milling, and wet screening. Among them, the water washing method is the most …
Utilisation of Water-Washing Pre-Treated …
Utilisation of Water-Washing Pre-Treated Phosphogypsum for Cemented Paste Backfill Yikai Liu 1, Qinli Zhang 1 ... water-washing, was proposed to remove impurities from PG. The pre-treatment of adding water and separating supernatant and precipitate by centrifuge is widely used as an effective and simple method of impurity removal in various ...
A flotation combined extraction process for improving …
with TBP extraction can remove impurities wrapped in PG, and the whiteness of the purified gypsum can reach more than 90%. ( Zhao, 2017) Zhao used a single extraction process of sulfuric acid combined with TBP to treat phosphogypsum containing 5.82% SiO 2. TBP and PG were then combined with 30
Influences of pretreatment methods on the mechanical …
phosphogypsum calcination temperature increases the pH. The water washing method can adequately remove phosphogypsum-soluble P 2 O 5, fluorine, organic matter and other impurities, however, the washing method will induce a huge amount of wastewater discharge, causing severe secondary pollution with adverse environmental impacts.
(PDF) In Situ Remediation of Phosphogypsum with Water-Washing …
The overall results proved that in treated phosphogypsum-based cemented paste backfill (TCPB), the altered particle size distribution can alleviate the shear-thinning characteristic.
washing can remove phosphogypsum
Reuse of Phosphogypsum Pretreated with Water Washing. WebJan 21, 2022 Further, as can be seen in Figure 11 (c), with the increase of pH value of pretreated PG, the concentration of SO 4 2-in the bleeding water of PG-1 and PG-2 groups gradually decreased from 40005000 mg/L to about 1300 mg/L. Overall, the water washing of PG could well remove the impurities, leading to …
Review of the State of Impurity Occurrences and Impurity …
Zhang et al. showed that the soluble fluorine content in phosphogypsum can be reduced from 0.250% to 0.023%, 0.02%, and 0.018%, respectively, when treated with lime neutralization, …
Experimental Study on Pretreatment of Preparing …
The principle of water washing method: the main impurity affecting the phosphogypsum can dissolve in water.The organic impurities mainly for oily substances above can float on water.Therefore, the water washing method can remove most of the phosphorus gypsum soluble impurities, including phosphorus, fluorine, most alkali metal salts and organic ...
Review of the State of Impurity Occurrences and Impurity …
A variety of co-existing impurities in phosphogypsum limit its large-scale and high-value utilization. This paper summarizes the common contents of major impurity components (silicon and ...
In Situ Remediation of Phosphogypsum with Water-Washing …
In this study, a water-washing pre-treatment was used to purify OPG, aiming to optimize the transport performance and mechanical properties of backfills. The overall results …
The Generation Process, Impurity Removal and High-Value …
As phosphogypsum constitutes a large amount of solid waste material, its purification treatment and comprehensive utilization have close connection with economic development and ecological environmental protection. ... Washing can remove most of the soluble impurities, but in terms of the environment, the sewage after washing must be treated ...
In Situ Remediation of Phosphogypsum with Water-Washing …
In this study, a water-washing pre-treatment was used to purify OPG, aiming to optimize the transport performance and mechanical properties of backfills. The overall results proved that in treated phosphogypsum-based cemented paste backfill (TCPB), the altered particle size distribution can alleviate the shear-thinning characteristic.
Influences of pretreatment methods on the mechanical and …
The water washing method can adequately remove phosphogypsum-soluble P 2 O 5, fluorine, organic matter and other impurities, however, the washing method will induce a huge amount of wastewater discharge, causing severe secondary pollution with adverse environmental impacts. The microwave method is restricted by a combustion time of around 20 ...
In-situ remediation of phosphogypsum in a cement-free …
Nevertheless, the methods of penetrating PG have different highlights and challenges, but all methods are intended to remove the impurities efficiently. Although the mechanical property is optimized, water washing is more efficaciously in removing water-soluble impurities in PG (Liu et al., 2021, 2019).
Reuse of phosphogypsum pretreated with water washing as …
Water washing could remove the majority of residual acids in PG. As the pH value of the pretreated PG reached 3.50 and 5.00, the pH value of the slurry reached around 12.8, …
Comparative analysis of colloid-mechanical …
Phosphogypsum is a kind of industrial byproduct mainly from the production process of wet-process phosphoric acid. Each ton of phosphoric acid produced will produce 5–5.5 tons of phosphogypsum [1], [2].The global phosphogypsum stockpile has exceeded 7 billion tons, the annual output is about 0.2 to 0.3 billion tons, and the utilization rate is less than 15% [3], [4].
Utilization path of bulk industrial solid waste: A review on …
Phosphogypsum occupies a lot of land and poses a serious pollution threat to the ecological environment. This paper mainly summarizes the existing pretreatment and resource utilization technology of phosphogypsum. ... 2002), and mainly focused on the following aspect, namely water washing method that can remove a large number of impurities such ...
Desilication and purification of phosphogypsum waste by …
Phosphogypsum (PG) is the main by-product of wet phosphoric acid production and has seriously polluted the environment. In this study, PG was purified by reverse flotation using a photosensitive azobenzene surfactant (PASF). ... Water washing can remove water-soluble phosphorus and fluorine, but it does not effectively improve the whiteness and ...
Production of high-quality gypsum raw materials from phosphogypsum
Water washing can remove a certain number of soluble impurities from the surfaces of PG crystals and greatly improve the workability and mechanical properties of PG-based cemented paste backfill ...
Usage of biowashing to remove impurities and heavy metals …
The storage of phosphogypsum could bring huge burden to the environment, while the traditional method of washing and purifying phosphogypsum produced a large amount of waste water and colossal ...
Mechanism of calcination modification of phosphogypsum and …
Calcination can not only remove impurities such as soluble phosphorus, soluble fluorine and organic matter in PG, and it is observed that during the heating process of PG at high temperature, the P 2 O 5 occluded in the gypsum crystals (CaHPO 4 ·2H 2 O) can convert into calcium pyrophosphate (CaP 2 O 7) which is water insoluble and harmless ...
Reuse of Phosphogypsum Pretreated with Water Washing …
(3) Water washing pre treatme nt signi can tly reduce d the impurities c ontent in the bleed in g water and the leachates of back ll. Eventually, almost of PO 4 3- -P, mor e than 99.3% of F ...