phosphogypsum for cement in Oman

PHOSPHOGYPSUM: A Review of the Florida Institute …

cement from phosphogypsum and phosphatic tailings sand. SO2 would have been produced as a by-product for conversion to sulphuric acid, The process was not successful in that it was not possible to obtain the high-quality cement product. With the funding of "Gypsum By-Product Exploitation," the Institute

Phosphogypsum circular economy considerations: A critical …

Phosphogypsum (PG) is the primary byproduct generated during the production of phosphoric acid, an intermediate product in phosphate fertilizer production, from calcium phosphate (apatite) ore. PG also exists in very small amounts in nature where it is the result of natural guano processes as they took for instance place in the …

Phosphogypsum-Based Ultra-Low Basicity Cementing Material

Traditional Portland cement is widely used in the preparation of various hydraulic concrete. However, the high alkalinity produced by cement hydration threatens the survival of aquatic animals and plants. In this paper, a new eco-friendly, ultra-low alkalinity, cementitious material was prepared with industrial waste phosphogypsum, …

Phosphogypsum-Based Ultra-Low Basicity Cementing Material

In this paper, a new eco-friendly, ultra-low alkalinity, cementitious material was prepared with industrial waste phosphogypsum, granulated ground blast slag …

Collaborative effects of red mud and phosphogypsum on

Red mud (RM) and phosphogypsum (PG) are two typical industrial waste around the world, which are being generated and landfilled massively per year. This study investigates the collaborative effects of RM and PG on geotechnical properties of cement-stabilized dredged clay. Unconfined compressive strength (UCS) tests, isotropically …

Investigation on mechanical properties of excess-sulfate phosphogypsum

In order to remove impurities in phosphogypsum, phosphogypsum can be modified by wet grinding. Under the condition of water to cement ratio of 0.43, phosphogypsum paste was prepared by mixing phosphogypsum, slag powder and cement at the ratio of 45:1:2, wet grinding for 1 h and aging for 24 h [11], [29]. PPSC …

Valorization of phosphogypsum in cement-based materials: …

Mortars and concretes produced with PG-based cementitious systems achieve high compressive strength levels (60 MPa, 70 MPa, 80 MPa) and accomplish the requirements of the European standards EN 998-1, EN 998-2, EN 13813, Eurocode …

Mechanical Properties and Optimal Mix Design of …

The optimal mix proportions for two types of lightweight soil, namely phosphogypsum cement microsilica (PGCF) and phosphogypsum cement slag …

Microstructural and Phase Characteristics of Phosphogypsum-Cement

The effects of the tricalcium aluminate (C 3 A) content of the stabilizing cement [Type II (1.3% C 3 A) cement and Type III cement (9.3% C 3 A)], curing time (seven to 90 days), proportion of PG (5–60%), grain size, and impurities in phosphogypsum (PG) (PG compared to gypsum) on the microstructural (by scanning …

The Development of a New Phosphogypsum-Based …

Many studies have suggested that phosphogypsum can be used as a substitute for natural gypsum to control the hydration reaction rate in Portland cement production . PG has also been used in the manufacturing of bricks: the incorporation of 30% of PG into annealed clay bricks provides a product that successfully satisfies the …

Utilization of weathered phosphogypsum as set retarder in Portland cement

In this study, usability of weathered phosphogypsum (PG) from residue areas as set retarder in Portland cement was investigated. The effects on the setting and mechanical properties of PG added in ratios 1, 3, 5, 7, 10, and 12.5 wt.% to Portland cements were studied and compared with a Portland cement containing natural gypsum …

Hydration mechanism of a sodium-doped phosphogypsum …

1. Introduction. Supersulfated cement (SSC) is a binder with little Portland cement clinker. It is usually made up of 75–85 % granulated blast furnace slag (GGBFS), 10–20 % calcium sulfate, and less than 5% alkaline activator [1], [2], [3], [4].SSC is a low-carbon cementitious material, and its main raw material, slag, comes from a by-product …

Incorporation of phosphogypsum with cement in rigid …

Phosphogypsum can be used as a partial replacement for cement in conventional concrete mixes, although its strength is diminished by the presence of …

Utilization of solidified phosphogypsum as Portland cement retarder

The utilization of the phosphogypsum (PG) as cement retarder is both an economical and an ecological approach to treat this solid waste. Cement using raw PG as retarder has two problems pressing for solution,namely, delaying the setting time and difficulty being fed into the cement mill. The soluble phosphates in PG behave as super …

Preparation and Micromechanics of Red Sandstone–Phosphogypsum–Cement

Based on the physical and chemical properties of red sandstone (RS), RS is used to produce composite cementitious materials. The flowability, mechanical strength, and micromechanics of a red sandstone–cement binary cementitious material (RS-OPC) were investigated as functions of the amount of RS replacing the cement (OPC). …

Study on the properties of an excess-sulphate phosphogypsum slag cement …

Excess-sulfate phosphogypsum slag cement (ESPSC) is a low-carbon cementitious material. It comprises 40–50 % PG, 30–40 % granulated blast furnace slag, and a small amount of cement as an activator [16]. The ESPSC exhibits excellent later-age compressive strength [17], sulphate resistance [18] and water resistance [19].

A Sustainable Composite Cementitious Material …

The phosphogypsum is a by-product of the phosphate fertilizer industry. It has accumulated over several decades, and not only takes up a large amount of land, but also poses a significant risk to the environment and resource waste. In order to promote the use of phosphogypsum, its hydration hardening characteristics are studied using a …

Hydration characterization of Mg2+ blended excess-sulphate

1. Introduction. As more than 300 million tons of phosphate fertilizer is produced for agriculture demands every year [1], [2], effective utilization of the by-product, phosphogypsum, has been put forward since 2010.Phosphogypsum-based excess-sulphate slag cement (PESSC), composed of more than 40% phosphogypsum, slag, …

Phosphogypsum

Abstract. Phosphogypsum is a by-product of the phosphate fertilizer industry. It is generally treated by stacking, which not only causes environmental pollution, but also wastes …

Treated phosphogypsum as an alternative set regulator and …

Singh, Treating waste phosphogypsum for cement and plaster manufacture, Cement and Concrete Research 32(7) (2002) 1033-1038. [12] M. Singh, Role of phosphogypsum impurities on strength and microstructure of selenite plaster, Construction and building materials 19(6) (2005) 480-486. [13] M. Taher, Influence of thermally treated …

Phosphogypsum as a construction material

Phosphogypsum (PG) is a by-product generated from the phosphorus fertilizer industry (phosphoric acid production). PG is similar to natural gypsum, but there are some differences, of which it contains some impurities such as water-soluble phosphate (P 2 O 5), water-soluble fluoride (F −) and P 2 O 5 substituted in the gypsum crystal …

Effect of Modified Phosphogypsum on Properties of Cement …

The Industrial Waste (phosphogypsum) is a waste product which was produced from the chemical industries. This waste material is used in concrete.

Wetting-drying effect on the strength and microstructure of cement …

The obtained homogeneous cement-phosphogypsum paste was transformed into a container 39.1 mm in diameter and 80 mm in height. The air bubbles were carefully removed by vibrating the container. The prepared sample inside the container was cured under standard conditions (temperature of (20 ± 2) °C and relative …

Development and optimization of phosphogypsum-based …

In this study, beta-hemihydrate phosphogypsum (β-HPG), slag, fly ash (FA) and alkali activator were mixed to form a phosphogypsum-based geopolymer (PBG) …

Effect of modified phosphogypsum on the hydration properties …

1. Introduction. Supersulfated cement (SSC) is a kind of environment-friendly cement as well as a newly developed non-burnt cementitious material with less clinker or even without clinker [1], [2].The common compositions of SSC are always about 75–85% ground granulated blast furnace slag (slag), 10–20% gypsum as sulfate activator, and …

Phosphogypsum

Building elements made of phosphogypsum, such as wallboards and similar construction elements, give yield to high values of radon emanation together with the mentioned elevated concentrations of 226 Ra. Phosphogypsum can be used in Portland cement as a setting time retarder in amounts below 4–5 wt%; then, it is diluted in the concrete and ...

Cement-Stabilized Phosphogypsum Synergistized with …

The unconfined compressive strength (UCS), split tensile strength (STS), freeze-thaw cycles, and shrinkage tests were used to evaluate the mechanical …

The Influence of Disused ZSM-5 on the Performance of Phosphogypsum …

Zeolite Socony Mobil-5 (ZSM-5) is a commonly spent catalyst in the petrochemical industry; and phosphogypsum (PG) is a kind of industrial waste produced in the process of phosphoric acid production. The environmental issues caused by these two solid wastes are urgent and thus sustainable methodologies are required to dispose of …

Modification of recycled cement with phosphogypsum and …

Some studies showed that the soluble phosphorus and fluorine in the PG would react with Ca(OH) 2 produced by cement hydration and then generate precipitates coating the surface of the cement particles, which would restrict cement hydration causing longer setting time and lower early strength [38], [39], [40]. Therefore, it is essential to …