2.2 Experiment Procedures. Figure 2 presents the process flow diagram of a novel approach for the separation and recovery of titanium, scandium, and iron from acidic wastewater and red gypsum utilization, which mainly embraces four experimental processes: (1) separation of titanium from acidic wastewater to obtain titanium …

In this experimental study, the physico-mechanical and microstructural properties of sulphate-bearing clays have been investigated. Sulphate bearing soils constituted by mixing kaolin and gypsum at 0%, 15%, 25%, and 35% gypsum contents were treated with 12% ordinary Portland cement (OPC) and 4%Lime (L) and 8% ground …

Physical extraction of gypsum from CRD waste and decontamination methods Over the last decade, recycling and valorization of CRD wastes have been studied in several research projects. It has been reported that a physical pre-treatment is important before the application of any method of valorization or management of CRD waste ( …

The impacts of quarrying of the gypsum deposits on the environment at Maqna, Tabuk, were evaluated by intensive field studies including in situ testing, mapping and sampling of gypsum and well water. Field and laboratory tests were made to determine the engineering properties including tensile and compressive strengths, unit weight, …

gypsum, common sulfate mineral of great commercial importance, composed of hydrated calcium sulfate (CaSO 4 ·2H 2 O). In …

Keywords: Gypsum; Mining Scheduling; T errace Mining; ... find more profitable alternatives for the extraction of this mineral good. ... 20% gypsum and 55% marble sludge waste) at firing ...

Here we report the mechanism by which gypsum rocks from the Atacama Desert, Chile, provide water for its colonizing microorganisms. We show that the …

SignificanceThis research provides an in-depth analysis of how microorganisms are able to survive in the world's driest non-polar place, the Atacama Desert, Chile. We show that these organisms extr...

A novel process that includes selective reduction roasting followed by hydrolysis was proposed in this work to recover zinc, and efficiently extract calcium and sulfur from hazardous zinc-rich gypsum residue (ZGR) waste for high-purity of CaCO 3 and sulfur production. The selective reduction behaviors of ZGR during the reduction roasting …

19 for gypsum extraction; quarry fronts have to be halted as soon as anhydrite is found. In this work the ... 37 Keywords: Gypsum, Anhydrite, Sulphate, Electrical Conductivity 38 39 . 3 40 1. INTRODUCTION 41 Evaporites are sedimentary rocks originated from evaporation of salty water. Sulphates are one

A gypsum content of 120 soil samples was determined by three methods; (1) standard silica-gel; (2) acetone; and (3) the proposed method (OMRAN GypSim). These …

PDF | On Jan 1, 2018, Júlio César de Souza and others published MINING SCHEDULING OF GYPSUM EXPLOITATION BY TERRACE MINING METHOD: AN ECO-SUSTAINABLE ALTERNATIVE | Find, read and cite …

Hazardous heavy metal-laden coal combustion byproducts exposed to precipitation or surface/groundwater are of environmental concern. This study analyzed fly ash (FA) and desulfurization gypsum …

Gypsum (calcium sulfate dihydrate) is one of the most used inorganic binding materials in the world. During calcination, calcium sulfate subhydrates are formed and, for technical reasons, are mixed with water to form dihydrate again. Therefore, the dehydration process of gypsum and the rehydration of hemihydrate were investigated. This …

Gypsum, but is comparatively limited in its technical applications. The content of Gypsum in sedimentary rock varies from 75% to 95%, the rest being clay and chalk. B. Extracting Natural Gypsum Gypsum/Anhydrite are produced from open-cast mines, or underground mines using pillar and stall mining methods, that give extraction rates of up to 75%.

Keywords: microorganisms, water extraction, anhydrite, gypsum, phase transformation Abstract Microorganisms, in the most hyperarid deserts around the world, inhabit the inside of rocks as a survival strategy.

Gypsum has been used in construction for over ten thousand years. Building gypsum is chemically hemihydrate calcium sulphate CaSO 4 ·1/2H 2 O, produced in the process of natural gypsum stone roasting [1, 2] or in the technology of gypsum extraction from flue gas desulphurization installations in coal-fired power plants [3, 4].There are two …

materials. So, in the devices for production of gypsum by fluidization process in the Factory of. y of combustion fuel oil, is used usefully, while. heat in the production of gypsum we must go by ...

Heavy metal-containing gypsum is a widespread hazardous waste. In this work, H + was found to be the most essential factor of the mineralizers in hydrothermal treatment to completely (≥99.8%) extract Cr(VI) from gypsum waste to the supernatant, where the significant growth (from several μm to several hundreds of μm) and perfection …

The proposed method for gypsum determination determines the water loss of a soil sample by heating at 70 °C and 135–150 °C, which allows an accurate estimate of the gypsum content of a soil using a recovery factor of 19.66%. In a laboratory, the gypsum content of 120 soil samples can be determined in 60 min work.

The gypsum industry is responsible for around 1% of the total amount of construction and demolition waste (CDW). It was estimated that every detached house with an area of 186 m 2 on average contains 1021 kg of gypsum drywall with a potential to become a CDW [].If gypsum CDW is disposed of in landfills, the production of hydrogen …

Gypsum is a naturally occurring mineral that is made up of calcium sulfate and water (CaSO 4 +2H 2 O) that is sometimes called hydrous calcium sulfate. It is the mineral calcium sulfate with two water molecules attached. By weight it is 79% calcium sulfate and 21% water. Gypsum has 23% calcium and 18% sulfur and its solubility is

Keywords: phosphogypsum material ... China is a large country and rich in calcium resources, with abundant reserves of natural gypsum and secondary gypsum resources . Natural ... found that after taking the method of physical extraction by selecting the appropriate organic extractor, Pb210, Ra226, K40 and U238 in PG could remove to …

Huang, W. et al. Mechanism of water extraction from gypsum rock by desert colonizing microorganisms. Proc. ... Search articles by subject, keyword or author. Show results from. Search. Advanced ...

Agricultural rainfed areas of Pakistan have been facing several issues in recent years, e.g., soil erosion, nutrient runoff, and soil dependency on rainfall for crop growth. Wheat is considered a major staple crop in Pakistan. The main concern in these regions is to conserve soil moisture as the crop depends on the moisture obtained by …

The Messinian gypsum of Sorbas is intensively karstified, with hundreds of dolines and numerous, highly unusual exo- and endokarstic forms. Amongst these the tumuli are especially spectacular, as are the large caverns, adorned with numerous speleothems, some of which have not been described anywhere else in the World. The extraction of …

Promoting the use of gypsum and gypsum-based materials in construction is a successful strategy from an environmental point of view; it allows a lower energy demand with a sensible reduction in carbon …

gypsum was 18.0 million tons. Synthetic gypsum is mainly produced as a byproduct in flue gas desulfurization (FGD) systems. Calcined gypsum is produced domestically from crude gypsum by heating selenite. In the United States, gypsum is primarily used to manufacture wallboard and plaster for homes, offices, and commercial buildings.

Abstract. There has been an increasing demand on the REE supply in the last few decades and special attention has been directed towards the extraction process of these elements. The impurity removal step is a key step in the processing circuit as it can determine the purity of the final product. Lime neutralization is deemed a preferred …

to prevent gypsum contamination. The extraction . of nickel and cobalt from ammoniacal leach . solution is conducted using an oxime extractant (LIX 84I). Three extraction stage and four strip .