The use of phosphoric acid waste product for calcium sulfide production

IOP Conf. Ser.: Earth Environ. Sci.

Yakovenko

et al. 2022

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The paper considers the process of processing phosphogypsum into an inorganic luminescent material. The synthesized materials were characterized using X-ray phase analysis and scanning electron microscopy. It has been shown that phosphogypsum reduced with sucrose exhibits the ability of luminescence under the action of ultraviolet radiation, glowing with yellow-orange light. A process for the recovery of phosphogypsum has been proposed. The results obtained open up the possibility of processing large-tonnage waste into demanded cheap materials.

Section: Resultsmentioning

confidence: 99%

Study of the process of processing phosphogypsum to obtain an inorganic luminescent material

IOP Conf. Ser.: Earth Environ. Sci.

Yakovenko

et al. 2022

Self Cite

“…Calcium sulfide, which is the basis of the phosphor, can be obtained by reducing calcium sulfate with a carbon-containing reagent [20]. The work [21] provides information on the reduction of phosphogypsum by a number of organic compounds (waste of olive oil production, citric acid, sucrose).…”

Section: Resultsmentioning

confidence: 99%

Development of technology for processing solid waste from the production of orthophosphoric acid into an inorganic composite material

IOP Conf. Ser.: Earth Environ. Sci.

Sidash

et al. 2022

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The article considers the processes of processing solid waste from the production of phosphoric acid - phosphogypsum - into composite inorganic materials. It is shown that heat treatment at a temperature of 1073 K leads to the formation of inactive calcium sulfate. Carrying out the heat treatment process under similar conditions in the presence of an organic reducing agent is accompanied by the formation of a composite material with a luminescent ability. A simple method for the disposal of large-tonnage production waste with the production of a demanded product is proposed.

“…Сульфид кальция служит матрицей для получения неорганических люминофоров [8][9][10]. В современном мире материалы с люминесцентными свойствами являются объектом интенсивного изучения ввиду широкого круга возможностей их использования [11][12][13].…”

Section: Introductionunclassified

Technology for processing phosphogypsum into a fluorescent dye based on calcium sulfide

2022

Fine Chem. Technol.

Objectives. There is considerable economic demand for products obtained by processing phosphogypsum. In particular, calcium sulfide-based materials having luminescent properties are the object of intensive study due to the wide range of possibilities for their use. The alloying of the structure of calcium sulfide with cations of rare earth elements leads to the appearance of a glow having various colors. However, the high cost of such phosphorescent materials is due to the high chemical purity of the reagents required for their synthesis. The development of efficient methods for obtaining calcium sulfide-based luminescent materials from phosphogypsum is part of an integrated approach to solving the problem of synthesizing economically demanded materials from production waste.Methods. The synthesized materials were studied using X-ray phase analysis and scanning electron microscopy. Photos of the samples were taken under illumination with an incandescent lamp or a fluorescent ultraviolet lamp.Results. According to X-ray phase analysis, phosphogypsum is mainly comprised of calcium sulfate dihydrate and calcium sulfate hemihydrate. Heat treatment of a phosphogypsum sample at a temperature of 1073 K is accompanied by the formation of anhydrous calcium sulfate. In the presence of a reducing agent, a composite material is formed containing a phase of anhydrous calcium sulfate and calcium sulfide. Due to the calcium sulfide content, phosphogypsum has luminescent properties when heat-treated in the presence of various reducing agents, including activated carbon, wood charcoal, vegetable oil, citric acid, starch, and sucrose.Conclusions. Optimal technological conditions for obtaining a composite material exhibiting luminescent properties are revealed. The successful synthesis of phosphor from without nonpretreated phosphogypsum is demonstrated. Optimal technological conditions for obtaining a composite material exhibiting luminescent properties are as follows: heat treatment temperature is 1073–1173 K; isothermal holding time is 60 min; reducing agent quantity is 37–50% (mol). The study results are widely applicable to processing wastes obtained from large-scale chemical production involving the production of a highly demanded inorganic product.