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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 …
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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 ...
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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 ...
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A simple and reproducible microbiological simulation procedure in combination with a chemical procedure was used to test concrete for its potential resistance towards biogenic sulfuric acid.Concerning fundamental aspects of the corrosion reaction, it was shown that particularly the penetration of H 2 S inside the concrete …
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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 …
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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
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Sustainability of gypsum products as a construction material. N. Lushnikova, L. Dvorkin, in Sustainability of Construction Materials (Second Edition), 2016 25.2.2 Gypsum …
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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. …
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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 ...
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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 …
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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 …
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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.
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A life cycle assessment also showed that the co-production of calcium sulfoaluminate cement and sulfuric acid using the decomposition of industrial by …
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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 …
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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 …
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In laboratory, the cement prepared using clinkers: ground calcined clay: low grades of limestone: gypsum in proportion as 50:30:15:5. This cement contains 53-grade OPC, which meets IS 12269–2013 [17].An X-ray fluorescence test was used to find out the material oxide constituents shown in Table 1.The specific gravity of prepared cement …
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1. Introduction. Microbial-induced concrete corrosion (MICC) is a major peril to underground structures, precipitating material degradation and curtailing the lifespan …
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Effect of Temperature and Acidity of Sulfuric Acid on Concrete Properties ... As the gypsum material is 65 eroded, the concrete loses its binder and begins to spall, exposing new surfaces. ... Sulphuric acid baths 4 143 …
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Of the precipitates, calcium sulfate – crystallizing mainly in the form of gypsum, calcium sulfate dihydrate (CaSO 4 ·2H 2 O) – is one of the most common representatives, which is present (or may form) in a large variety of natural and industrial processes, such as acidic wastewater treatment, phosphonic acid production, wet flue …
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@article{Wu2020CopreparationOC, title={Co-preparation of calcium sulfoaluminate cement and sulfuric acid through mass utilization of industrial by …
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Current established technology for making sulfuric acid (H 2 SO 4) and cement clinker by-product from phosphogypsum (such as the OSW process developed by Chemie Linz, Austria) is not economic when compared with sulfur burning.It has only been applied in a few locations (Austria, China, and South Africa) where special circumstances prevail.
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Composed mainly of calcium sulfate dihydrate, gypsum is a naturally occurring mineral used in cement, drywall, plaster and other building materials. Scientists have now devised a method of ...
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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.
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To study this possibility, it is vital to determine whether IBP gypsum can be effectively decomposed to form clinker minerals in a normal manner and whether the SO …
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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 Sulphuric …
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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 …
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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 …
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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.
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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 ...
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Pointing out that industrial routes such as preparing sulphuric acid co-production cement, calcium ferrite and conversion of ammonium to sulphuric acid by industrial gypsum are feasible, which ...
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