An accelerated sulfuric acid spraying test in a custom-made spraying ... the formation of gypsum (i.e., the main corrosion product of concrete) during the performed tests, by X-ray Diffraction ...
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 …
be related to weight gain of sulfuric acid-exposed cement concrete in early exposure periods, which has been reported in many other studies. Chang et al. suggested that such weight gain could be attributed to many factors, including continuous cement hydration, formation of gypsum due to acid attack, and increase in absorbed water of specimens [20]
1. Introduction. Concrete durability refers to the resistance of concrete against the action of aggressive environmental media which threaten the normal service of concrete components [].The actions of these aggressive environmental media are usually summarized as acid attack [], sulphate attack [], and chloride-induced corrosion [].In the …
A method and apparatus for recovering calcium sulfate di-hydrate (gypsum) from a precipitation reaction between cement kiln dust and commercial, spent or waste grade sulfuric acid solution. The gypsum recovered from this process acts as a necessary functional additive for use in the production of hydraulic Portland cement. The invention …
The experimental raw material was fly ash from Shuozhou Second Power Plant of China, and the composition of fly ash was analyzed by XRF spectral qualitative analysis combined with chemical total analysis, the result was shown in table 1.The main chemical composition in fly ash were SiO 2, Al 2 O 3, Fe 2 O 3 and CaO. The physical …
Gypsum (CaSO4. 2H2O) is produced by increasingly more industrial processes, for instance, when calcium carbonate or lime is used to neutralize sulfuric acid containing effluents or when apatite (Ca3(PO4)2. CaF2. CaCO3), the raw material used in phosphoric acid manufacture, is attacked by sulfuric acid.
which is made of sulfuric acid modified steel slag, β-hemihydrate gypsum and calcium aluminate cement. With this, the hydration rate of anhydrite-Ⅱ phosphogypsum is clearly increased and setting time shortened. The performance of self leveling mortar prepared is as per JC/T 1023-2021, with softening coefficient of 0.8. 1. …
DOI: 10.1016/j.jclepro.2020.121801 Corpus ID: 219064874; Co-preparation of calcium sulfoaluminate cement and sulfuric acid through mass utilization of industrial by-product gypsum
The idea was to use Iowa natural gypsum to produce sulphuric acid and lime, two of the most widely used industrial chemicals, and thereby create a chemical …
To study the sulfuric acid corrosion resistance of geopolymer concrete (GPC) with different binding materials and concentrations of sodium hydroxide solution (NaOH), metakaolin, high-calcium fly ...
In this method, the concrete prims are immersed in sulfuric acid solution at a constant pH of 2. During the first weeks, a high precipitation of gypsum occurs on the …
In the process as originally designed, a dry ground rawmix was made comprising anhydrite (or gypsum), shale and/or ash, sand and coke. ... "Production of Cement and …
A new production technique for manufacturing cement and sulphuric acid by using phosphogypsum is to combine the calcination process of nodulized phosphogypsum in hollow kiln with the advantages of vertical cylinder preheating kiln and off-kiln decomposition kiln and to increase the nodulizing system and nodule dryer. The said new technique …
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 ...
II. GENERAL FEATURES OF SULFURIC ACID ATTACK Sulfuric acid [H2 (SO4)] attack on concrete may be characterized by a chemical reaction between the acidic media and cement hydration products and, if soluble, the aggregate particles, results in excessive formation of gypsum (Fig. 2.1). The nature of attack of sulfuric acid on concrete is …
Biogenic sulfuric acid corrosion is often a problem in sewer environment: it can lead to a fast degradation of the concrete structures. Since the involvement of bacteria in the corrosion process was discovered, considerable microbiological research has been devoted to the understanding of the corrosive process.
Acid etching concrete is an option but not a requirement for epoxying a concrete surface. If you plan to epoxy your garage floor, for example, it does need to be thoroughly cleaned and free of contaminants, and the pores need to be opened. Acid etching is just one way to do this, but it's not the only way.
The corrosion of alkaline concrete materials exposed to a sulfuric acid environment is becoming more and more prevalent, and its damage assessment is becoming more and more imperative. This study aims to describe the corroded surfaces of concrete with different strength grades (C30, C50, C80) in sulfuric acid environments …
Industrial by-product gypsum is a waste by-product containing mostly calcium sulfate. Problems related to its storage and utilization have become a bottleneck restricting the development of various industries. The authors investigated the feasibility of co-producing calcium sulfoaluminate cement and sulfuric acid through the mass utilization of …
The cement prepared from limestone and pozzolana showed greater resistance to sulfuric acid attack when immersed in a 3% H 2 SO 4 solution compare to OPC [11]. Compared to concrete with inert aggregates, marble concrete displayed less degradation when subjected to sulfuric acid immersion test and impact resonance tests …
A life cycle assessment also showed that the co-production of calcium sulfoaluminate cement and sulfuric acid using the decomposition of industrial by …
An accelerated sulfuric acid spraying test in a custom-made spraying chamber used to examine the consumption of magnesium hydroxide coating, which was applied on poly (methyl methacrylate) plates, instead …
In this case, sulfuric acid attack test method using the autotitrator helped and the gypsum blended CSA cement experienced more damage than CSA cement. In spite of having marginally higher strength of gypsum-blended CSA cement, its acid resistance was found to be poorer. 5. Conclusions. Main conclusions of the study are summarized …
@article{Wu2020CopreparationOC, title={Co-preparation of calcium sulfoaluminate cement and sulfuric acid through mass utilization of industrial by …
Adjustments made to the sulfuric acid solution could have . ... formation of gypsum, and compressive strength, as well as the relationship among the formation of ettringite, pore structure, and ...
The cement clinker made from limestone carries from 0.10 percent to 2 percent S03 according to the fuel and raw materials used in making. ... Process for directly producing sulfur xide and sulfuric acid using gypsum as raw material US8623319B2 (en) * : : Xiaolin Yin ...
The degree of concrete deterioration is increased by alternate wet-dry cycles of exposure to sulfuric acid. The rate of concrete deterioration along the penetration depth of sulfuric acid could be ...
A sulfuric acid attack causes hardened cement to be eroded due to internal expansion pressure generated by gypsum formation in pores through the reaction between Ca(OH)2 and sulfuric acid.
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 ...
C04B7/04 — Portland cement using raw materials containing gypsum, ... Method for preparing sulfuric acid by reducing and decomposing gypsum with pyrite CN111118280A (en) * : : ... Public …
Gypsum, the most important raw material of plaster's industry, is a rather interesting example from this point of view as world's known resources are estimated at 2.34 billion tons, which roughly ...
The sulfuric acid resistance of the composite cementitious system of ordinary Portland cement (OPC)/calcium sulfoaluminate (CSA) cement is presented in this paper. Specimens were exposed to sulfuric acid solution for 70 days, and deterioration was evaluated in terms of visual appearance, mass change, and compressive strength …
In addition, when the concrete made using ordinary Portland cement (OPC) is exposed to a sulfuric acid environment, the dissolution of CH occurs followed by the formation of gypsum (CaSO 4 ·2H 2 O). This process introduces further damage due to sulfate attack, i.e., expansion due to ettringite formation and subsequent cracking, as …
The biogenic sulfuric acid corrosion simulation device is schematically shown in Fig. 1, which has been modified based on the one reported in literature [18].H 2 S is produced in part 1 while part 2 conducts the biogenic sulfuric acid corrosion. H 2 S was produced by Na 2 S (0.086 M) and HCl (0.042 M). Volumetric flow of Na 2 S and HCl …
1. Introduction. Microbial-induced concrete corrosion (MICC) is a major peril to underground structures, precipitating material degradation and curtailing the lifespan …
Geopolymer binder is expected to be an optimum alternative to Portland cement due to its excellent engineering properties of high strength, acid corrosion resistance, low permeability, good chemical resistance, and excellent fire resistance. To study the sulfuric acid corrosion resistance of geopolymer concrete (GPC) with …
Recycled concrete aggregate (RA) is composed of original aggregate and attached mortar, both of which are essential in determining the durability and mechanical characteristics of recycled concrete. In this investigation, the sulfuric acid resistance of geopolymer concrete (GPC) was assessed using various RA types, incorporating …
Background Gypsum is a valuable resource for farmers, supplying essential calcium and sulfur for plant growth. It serves as a crucial soil amendment, particularly in reclaiming alkali and sodic soils. While …
The reaction between the cement particles on the concrete surface produces AFt, gypsum, ... 10%, 20%, 30%, 40%, and 50%) and SF (5%) on the durability of concrete against sulfuric acid attack and the control of drying shrinkage. 2. Materials and Methods 2.1. Materials. In this research, the concrete specimens were made using …