For this, the sulfuric acid gypsum process was used to process the Algerian phosphogypsum, and it was shown that a significant amount of sulfur can be recovered from the process. Experiments carried out in this research have enabled us to recover the sulfur in the form of SO 2 using appropriate additives such as silica, alumina, clay, and ...

The sulfuric acid reacts first with the calcium hydroxide (CH) to precipitate gypsum (CaSO 4 2H 2 O) on and below the concrete surface, which can induce tensile …

Fig. 1 shows the arsenic extraction from gypsum in the NSF system and in bulk sulfuric acid solution (SS) at different initial volume fractions sulfuric acid (φ(H 2 SO 4) ini), temperature and time.The arsenic content in the initial solid was 22.6 mg/g, which is the typical concentration of arsenic in the actual solid waste. With increasing the φ(H 2 SO …

PG is used to produce cement, brick, block, and gypsum board in India. However, the United States and other developed countries basically adopt stockpiling …

Phosphogypsum (PG), a waste product of the phosphate fertilizer industry, is a source of environmental pollution. PG can be calcined to form the hemihydrate gypsum (β-CaSO 4 •0.5H 2 O, HPG), making it a potential substitute to natural gypsum. However, PG contains large amounts of soluble phosphorus(P) impurities, which pose a serious …

The gypsum used at Leverkusen was in fact synthetic, phenol being purified as the calcium salt, and released by addition of sulfuric acid. The new process allowed the sulfuric acid to be regenerated. Other less-probable kinds of syngyp have also been proposed for the process, the inevitable presence of impurities being a major objection.

The present study investigates the potential of carbonation-cured belite-rich cement (BRC) to resist magnesium sulfate (MgSO 4) and sulfuric acid (H 2 SO 4) environments. BRC mortar was submerged in 5% and 10% MgSO 4 and H 2 SO 4 solutions. The gains of the compressive strength and mass under MgSO 4 environment …

The environmental impact of the co-preparation process of CSA cement and sulfuric acid using IBP gypsum decomposition was evaluated using a life cycle assessment (LCA) procedure specified in the ISO 14040 series (Simapro 9.0). The entire life cycle of the CSA cement and sulfuric acid co-production, from the cradle to the …

3 Citations. Metrics. Abstract. Phosphogypsum (PG) is a solid waste product generated during wet-process phosphoric acid production. Various impurities …

Characteristics: Rock gypsum is composed mainly of the single mineral, gypsum. Gypsum is very soft (softer than a fingernail and so can be scratched by a fingernail). It's color is typically clear or white, but can take on color from impurities, such as pink or yellow. It will not effervesce (fizz) in dilute HCl acid.

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Therefore, acids can easily deteriorate concrete in various ways. Notably, sulfuric acid (H 2 SO 4) is one of the most harmful acids to act on concrete materials due to its combined effect of acid and sulphate attack [52]. It reacts with the calcium hydroxide (CH) of the hydrated cement paste, and produces gypsum.

Cement and concrete products can be subjected to attack by various inorganic and organic acids including sulfuric, nitric, hydrochloric, phosphoric, acetic, lactic, and so on. However, sulfuric acid can be considered as the most common cause of deterioration of these products, since attack by which occurs in many various and popular ways.

The deleterious mechanism of acid attack is the dissolution of calcium hydroxide (a hydration product of cement paste) and the formation of gypsum (Ca 2 SO 4 .2H 2 O) and ettringite (Ca 6 Al 2 (SO ...

INTRODUCTION. Gypsum (CaSO4 . 2H2O) is produced by increasingly more industrial processes, for instance, when calcium carbonate or lime is used to neutralize sulfuric …

In this study, the feasibility of co-preparing CSA cement and sulfuric acid using the decomposition of IBP gypsum is investigated. This technology will allow …

Request information. Sep 10 2012. Applied Rigaku Technologies (Japan) recently announced a new empirical method for the analysis of sulphur in gypsum. Gypsum is a …

The reductive decomposition of PG to produce sulfuric acid is a good way to utilize this material. ... Using phosphor-gypsum (PG) to produce sulfuric acid is one of the most effective ways of ...

The natural gypsum is mainly used as a cement manufacturing retarder [1–3], while secondary gypsum (industrial by-product gypsum) is ... phate ore is …

Acidic solutions are the most destructive to concrete. Sulfuric acid attacks in two ways. first, the H 2 SO 4 reacts with hydration products such as C–H and C-S-H to form gypsum, and further in the second stage, ettringite (C6AS3H22 form due to reaction of tri-calcium aluminate hydrated (C 3 A) with gypsum [20].

These images clearly showed the formation of cracks in the cement incubated with the sulfuroxidizing bacteria. Such cracks are typical of cement pastes corroded by sulfuric acid, which reacts with calcium hydroxide and calcium aluminate in the cement to form gypsum .

Call +1 800 752 8878. Current established technology for making sulfuric acid (H 2 SO 4) and cement clinker by-product from phosphogypsum (such as the OSW process …

Section snippets Modelling of the chemical reactions of biogenic acid attack of cement mortar. Considering Portland cementitious materials, portlandite (CH) and calcium silicate hydrates (C–S–H) are the solid phases able to react with sulfuric acid to form gypsum (C S ¯ H2). These global reactions can be understood by combining three …

Abstract. This study presents an investigation into the durability of geopolymer concrete prepared using blended ash of pulverized fuel ash (PFA) and palm oil fuel ash (POFA) along with alkaline activators when exposed to 2% solution of sulfuric acid for up to 18 months. Ordinary Portland Cement (OPC) concrete was also …

PDF | The research addresses the issue of utilization of neutralized spent sulfuric acid pickling liquor, deposited in 1.62 ha lagoons, derived from... | Find, read and cite all the research you ...

The compressive strength loss of the cement mortars exposed to sulfuric acid for 70 days is shown in Fig. 6. As expected, the mortar specimens attacked by sulfuric acid showed different degrees of damage deterioration, and the higher the acid solution concentration, the greater the mortar damage. Download : Download high-res image …

An inner cement-lined 8–15 cm pipe is used to transport the melted sulfur to the surface. Compressed air is passed through the 2.5 cm tube in the center to airlift the sulfur. ... In spite of its wide usage, sulfuric acid rarely is contained in the final product. Sulfuric acid ends up as gypsum in phosphate fertilizer manufacture, for example ...

plant for gypsum from line and sulfuric acid ..., Posts Related to sulphuric acid cement gypsum. directories sulfuric acid plants pakistan. ... gypsum and sulfuric acid in the manufacture of white cement ... Go to Product Center. sulfuric acid used for mining gypsum - Quartz Crusher, How I can produce white cement and sulfuric acid from …

Used sulfuric acid can be recovered from the residuum resulting from the process of the purification of coal-oils with sulfuric acid by treating the residuum with water heated or caused to boil by ...