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
DOI: 10.1016/j.cej.2022.138594 Corpus ID: 251523098; Usage of biowashing to remove impurities and heavy metals in raw phosphogypsum and calcined phosphogypsum for cement paste preparation
This study contributes to sustainable construction practices by exploring the use of phosphogypsum, a commonly discarded byproduct, in the production of recycled aggregates. Addressing both environmental and economic aspects of sustainability, we investigate the feasibility of employing phosphogypsum as a primary raw material, in …
"The generation of acidic leachates from phosphogypsum (PGL) stacks is a global problem due to their high pollutant concentrations (As, Cr, Cd, Cu, Ni, Zn, F-, PO 4 3-, SO 4 2-, 210 Po and 238,234 U). The cleaning treatment of the PGL by neutralization with alkaline reagents is a proper option for removal of pollutants by (co)-precipitation.
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 …
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 …
In this research, thus, a pre-treatment method, water-washing, was proposed to remove impurities from PG. The pre-treatment of adding water and separating supernatant and precipitate by …
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).
Further, as can be seen in Fig. 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 4000 to 5000 mg/L to about 1300 mg/L. Overall, the water washing of PG could well remove the impurities, leading to lower concentrations of …
Phosphogypsum, as a byproduct of wet-process phosphoric acid reaction, has caused many environmental pollution problems. To improve the property and purity of phosphogypsum in the wet-process phosphoric acid process, a liquid–solid–liquid three-phase acid hydrolysis synergistic extraction reaction system was established by adding …
1. Introduction. Phosphogypsum (PG) is a bulk industrial solid waste of wet-process phosphoric acid production. Every ton of phosphoric acid production generates as many as 4–6 tons of PG, including more than 90% of CaSO 4 ·2H 2 O, a small amount of phosphorus, fluorine, organic matter, oxides, heavy metals, radioactive substances …
Minerals 2019, 9, 175 4 of 20 2. Materials and Methods 2.1. Raw Materials and Water-Washing Pre-Treatment OPC 42.5R (similar to ASTM C150 Type I cement [35]) and OPG with moisture content of
The contact angle between the superhydrophobic phosphogypsum coating (SPG coating) and water was 156°, and the coating reached a superhydrophobic state with good self-cleaning ability. Even when sandpaper was used to polish the coating, the water contact angle of the coating was still greater than 150°, indicating that the coating had …
The calcination treatment for recycling phosphogypsum (PG) is very promising, which can transform PG into a binder material and remove harmful impurities. To effectively recycle and reutilize PG, the influence of calcination temperatures on the properties of calcined and hydrated PG with and without pretreatment should be …
Among common pretreatments, washing can remove harmful impurities, including soluble phosphorus, soluble fluorides, organic matter, and residual acid, which can significantly improve the properties of PG [8]. ... Phosphogypsum (PG) has not been used effectively as cementitious material due mainly to the adverse effects of the soluble …
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 …
The washed phosphogypsum (PGW) was obtained by washing the PGF; this was placed in a large sieve and washed several times until the wash water obtained a neutral pH (between 6.7 and 7). The PGW was left to dry in the open air for 7 days. ... Based on our results, phosphogypsum can be considered to be a source of gypsum …
These impurities can restrict the reuse of phosphogypsum as a secondary primary resource. Consequently, large quantities of produced PG are stored in surface stockpiles that occupy extensive land areas and may pose a significant risk of ecological contamination to the surroundings. ... The salts or a²cids not removed during washing of …
The current trends focus on purifying PG by different methods: (1) water washing, which could remove dissolved phosphorus and fluorine, but wastewater treatment as a byproduct is a major concern, and the solution is not effective for eutectic phosphorus removal 4; (2) floatation method can remove the organic matter but the …
Therefore, the water-washing pre-treatment can effectively remove some of the soluble compounds in PG, whereas other impurities that are insoluble will likely be difficult to remove.
Phosphogypsum is the radioactive waste from phosphate ore processing that can contain carcinogens and toxic metals. Learn why conservation groups are petitioning the EPA to …
Phosphogypsum circular economy considerations: A critical review from more than 65 storage sites worldwide ... The treatment methods vary and may include washing, filtration, calcination, neutralization, leaching, and purification, among others, to remove impurities and further reduce the radioactivity levels. The specific process used …
Abstract Red mud and phosphogypsum are staple solid wastes, with considerably large annual emissions. Improving their comprehensive utilization is the key to addressing the large accretion of both red mud and phosphogypsum. They have great utilization potential and can be collectively modified to expand the utilization field and …
(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 ...
Phosphogypsum (PG) is a massive industrial solid waste. ... and using citric acid solution pretreatment to convert phosphorus and fluorine in PG into citrate that can be removed by water washing ...
Phosphogypsum is a solid waste byproduct from processing phosphate ore to make phosphoric acid that is later used in fertilizer. Phosphogypsum contains radium, which decays to form radon gas. Both radium and radon are radioactive and can cause cancer. The Clean Air Act regulations require that phosphogypsum be managed in …
Phosphogypsum (PG) waste is a by-product generated from wet-process phosphoric acid (H 3 PO 4) manufacturing during phosphate rock decomposition.Worldwide, the annual production of PG ranges between 100 and 300 million tons, with only a few quantities utilized in several application domains (about 15%), the …
Phosphogypsum is the most significant industrial solid waste in the world. Phosphogypsum has a complex composition and its traditional storage methods occupy large areas of land and also damage the environment. Currently, phosphogypsum is mainly used for the direct preparation of construction materials and chemical auxiliary …
Among common pretreatments, washing can remove harmful impurities, including soluble phosphorus, soluble fluorides, organic matter, and residual acid, which …
PDF | Recycling phosphogypsum (PG) for cemented paste backfill (CPB) has been widely used at phosphate mines in China. ... Therefore, the water-washing pre-treatment can effectively remove some of ...
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 ...
PG-3 needed fewer washing times to remove the imp urities. e 5% di erence in removal e ciency between two adjacent washes is de ned as the stab ilization of PG in this study . As seen in Fig. 5 b ...
As can be seen from the above, phosphogypsum has a good solidification effect on the washed MSWI fly ash, and the use of washed MSWI fly ash as an auxiliary material for phosphogypsum is safe ...
DOI: 10.1016/j.jece.2023.111485 Corpus ID: 265318021; Evolution of the waste generated along the cleaning process of phosphogypsum leachates @article{PrezMoreno2023EvolutionOT, title={Evolution of the waste generated along the cleaning process of phosphogypsum leachates}, author={S.M. P{'e}rez Moreno and …
Figure 11 a–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 …
Phosphogypsum can be chemically treated and become more suitable for the use of cementitious systems at a large scale in a more economical way. ... simple water washing or wet sieving, but all impurities are not removed ... The use of heat treatment can remove all impurities by subjecting the phosphogypsum to a temperature between 130 …
Physical methods are categorized as water washing, flotation, screening, etc. [20, 21]. The soluble impurities in phosphogypsum can be effectively removed . 95% of phosphorus can be removed after taking the removal rate of soluble phosphorus as the target and determining the optimum process .