Fluorogypsum (FG) is a byproduct of hydrofluoric acid production. In China, production of one ton of HF can produce four to five tons fluorogypsum. Over 400 million tons of fluorogypsum have been generated by 2010. Most of the generated fluorogypsum is transported to waste dumps stacks requiring large amounts of land …
FLUOROGYPSUM is also known as anhydrous calcium sulphate USES FLUOROGYPSUM can advantageously replace traditional cement as a binder for screed mortars. It is widely used in floor screen applications because of its numerous advantages: better fluidity for self-levelling, greater dimensional stability, high mechanical strength and outstanding ...
Due to the high cost of limestone as an oyster cultch material in the State of Louisiana, an economical, locally available material is needed to provide a binding substrate for the oysters. Fluorogypsum (CaSO4·H2O), a by-product of the hydrofluoric acid production process, is a low cost, locally available material that is currently being utilized as road …
The content of fluorogypsum is not higher than 40% and the content of fly ash must be more than that of fluorogypsum. Steam curing increases the early strength and enhances the rate of strength increase of the binder. The hydration mechanism of the binder is changed in elevated temperatures. This binder is suitable to manufacture …
The industrial waste fluorogypsum (FG), which has adverse effects on people and the environment, is composed of calcium sulfate (CaSO ... early strength agent, and water reducing agent as additives together formed the raw mate-rial of the new FG-based paste filling material. Meanwhile, FG was replaced by sulfoaluminate cement and ...
A large number of ettringite crystals and the remaining board-like gypsum crystals took each end and constituted the structural skeleton. The filamentous network-like calciumsilicate-hydrate(C-S-H) gel bonded firmly together with ettringite crystals, dehydrated gypsum crystals and granular tailings, and formed an extremely dense whole.
In order to explore the influence of the types of waste gypsum on the properties of alkali slag cement, fluorogypsum (FG) and flue-gas desulfurization (FGD) gypsum were comparatively investigated. Moreover, the action mechanisms of FG and FGD gypsum on the properties of alkali slag cement were analyzed. The results show that both the FG …
Introduction Fluorogypsum (FG), a waste of hydrofluoric acid industry, has been studied for use as building material . Water-resistant binding materials can be produced from phosphogypsum, slag, cement, fly ash and lime sludge. Impurities (fluoride) present in FG may interfere with setting and strength development of plaster/ building …
The most common gypsum by-product is FGD gypsum, formed from coal-fired power plants, though synthetic gypsum can also be generated through various acid-neutralizing processes. Additional types of synthetic gypsum include titanogypsum, phosphogypsum, fluorogypsum, and citrogypsum. Composed of calcium sulfate dehydrate, ...
The enhancement in strength with hydration period was due to the conversion of fluorogypsum into gypsum through formation of intermediate unstable salt. The reaction products were characterised using X-ray diffraction and scanning electron microscopy (SEM) techniques. SEM studies showed the appearance of prismatic and needle …
Fluorogypsum (FG) is a by-product of the production of hydrofluoric acid and mainly consists of anhydrite. Flue-gas desulfurization (FGD) gypsum is the waste produced during the flue-gas desulfurization …
In this paper, microbial induced calcite precipitation (MICP) was adopted as a modifying technology for surface property enhancement of supersulfated cement (SSC) containing phosphogypsum (PG).
Upon the addition of fluorogypsum, which provides SO 4 2-, AFt is formed as part of its hydration products (see (5), (6)). Simultaneously, with the inclusion of 10 wt% fluorogypsum and 0.2 wt% KH 2 PO 4, altering the pH value of the cement slurry leads to an increased generation amount of AFt along with a modified morphology characterized …
σΔs –work performed by the system when a new surface is formed, or energy released or absorbed ... fluorogypsum binder – sodium sulfate – water (Figure 4). The first intensive heat release ...
Fluorogypsum and KH 2 PO 4 can shorten the setting time and increase the compressive strength of calcium aluminate cement. • Fluorogypsum contributed to …
Fluorogypsum is a coproduct of the production of hydrogen flu oride (HF). In the process, fluorspar (caleium fluoride) reacts with condensing sulfuric acid (H2S04) to form HF gas and calcium sul fate. The reacted fluorspar leaves the reactor as solid calcium sul fate …
The employed fluorogypsum in this work is a kind of industrial waste residue, which is recycled from the source and used as roadbed material after solidification with sludge. ... kept stable, which suggests that ettringite formed rapidly in the early stage (one week), wouldn't continue to grow slowly in the later stage and result in expansion ...
Activation of fluorogypsum for building materials. Introduction Fluorogypsum (FG), a waste of hydrofluoric acid industry, has been studied for use as …
The mixture composition of composite binders prepared by blending the beneficiated ground fluorogypsum with granulated blast furnace slag (Fineness 400 m 2 /kg (Blaine), Portland cement and activators in different proportions followed by inter-grinding in a ball mill to a fineness of 410 m 2 /kg (Blaine) are given in Table 4.The …
The specific surface areas of sealed-cured hardened cement pastes (HCP) were evaluated during the hydration process using three types of Portland cement and with two different water-to-cement ratios.
Fluorogypsum, fly ash, Portland cement, and alum were blended. The mixture was ground in a ball mill to a fineness similar to that of Portland cement. ... A dense structure was formed in both pastes. When the percentage of alum added was high, some ettringite clusters formed (Fig. 7). It could produce local stress that is harm to the …
This article presents results of a research on changes in energy parameters of fluorogypsum composition of normal consistency with introduction of various additives (μΔn) such as construction gypsum G-5AII and sodium sulfate. The effects were assessed by temperature changes in the binder – water system. In order to compare processes of …
The microstructure of the composite pastes was formed of a framework of gypsum crystals, which formed in the initial stages; the matrix was later densified by the formation of C–S–H and ...
Auxins are hormones that have central roles and control nearly all aspects of growth and development in plants 1,2,3.The proteins in the PIN-FORMED (PIN) family (also known as the auxin efflux ...
Fluorogypsum is the waste residue produced by using fluorite to produce fluorine chemical products in the industry. Every 1 ton of fluorine chemical products produced usually produces about 4 tons of fluorogypsum [7]. ... and C-S-H gel with Ca/Si ratio of 1.08 ∼ 1.78 was also formed in the product to improve the mechanical …
The industrial waste fluorogypsum (FG), which has adverse ... and water reducing agent as additives together formed the raw mate-rial of the new FG-based paste filling material. Meanwhile, FG was ...
The Hawai'ian Islands are a chain of volcanoes in the middle of the Pacific Plate, which have formed due to the presence of a hot spot. The Hawai'ian hot spot causes magma to rise and erupt as lava on the ocean floor. …
In addition, the addition of slag to concrete decreases the formed Ca(OH)2 by reaction with slag to form the additional amounts of CSH (tobermorite), which enhances the compressive strength. These hydration products fill up the open pores, leading to the formation of a more compact body. ... Fluorogypsum, a waste from hydrofluoric industry ...
Given the issues related to poor hydration activity, long setting time and low early strength of industrial by-product fluorogypsum (FG), the composite modifiers (Na 2 SO 4 and NaNO 2) were utilized to enhance its reactivity.The investigation of the mechanism involved the utilization of contemporary analytical methods, including X-ray …
The invention provides a fluorogypsum-base external wall thermal-insulation material which is composed of the following raw materials in parts by weight: 100 parts of fluorogypsum powder, 10-15 parts of semi-hydrated gypsum powder, 8-14 parts of fly ash, 10-20 parts of cement, 0.5-3 parts of excitant, 0.1-0.25 part of fiber, 3-8 parts of ing …
Present studies deal with the formulation of sulphate resistant super sulphated cement using flourogypsum (83 %), granulated blast furnace slag (10 %) and OPC (7%) by …
The raw materials like fluorogypsum, GBFS and ordinary Portland cement were supplied by M/s Meta Dynamics, South Africa to formulate super sulphated cement. 2.1 Fluorogypsum The sample of fluorogypsum having a fineness of 3200 cm2/g, Blaine was dried at 42oC to constant weight and cooled to ambient temperature.
The acceleration mechanisms of the two were also found to be different: K 2 CO 3 increased the hydration of fluorogypsum by forming an unstable double salt …
To enhance both early strength and mitigate potential surface frost issues in fluorogypsum samples, we employ a combination of sodium nitrite and sodium sulfate. …
PDF | In order to explore the influence of the types of waste gypsum on the properties of alkali slag cement, fluorogypsum (FG) and flue-gas... | Find, read and cite all the research you need on ...
Fluorogypsum, a by-product of hydrofluoric acid manufacturing; Phosphogypsum, a by-product of phosphoric acid manufacturing; Titanogypsum, a by-product of titanium dioxide manufacturing. ... FGD gypsum is formed when fossil-fueled power plants utilize flue gas desulfurization systems to remove sulfur dioxide from gas pollutants. Using a process ...
This paper investigates the mechanical properties under laboratory and field conditions of a concrete-like blend made of fluorogypsum (FG), fly ash, and Portland cement for artificial reef ...
The study explores the influence of polycarboxylate admixture (PCE) on fluorogypsum-based self-leveling material (FSLM) performance. Wev conducted an array of tests to assess workability and mechanical properties, and utilized XRD, TG-DSC, SEM, and MIP techniques for microscopic analysis. The fresh state results showed that PCE …
