Mining Industry in the Sultanate of Oman with particular reference to chrome ore had been quite passive until Gulf Mining Group stepped into this field in 2005. Gulf Mining Group is presently among the largest mining companies in Oman and quite easily the market leader in production and export of chrome ore from Oman. Gulf Mining Group has played a major role in establishing Omani chrome ore in the world market. Starting off on a modest scale in 2005, it has now emerged as one of the largest producer and exporter of Chrome Ore. The group offers chrome ore in lumpy and fines form with chrome content ranging from 24% to 38%. Current production is 50,000 MT per month.
With a view to add value and to meet customer expectations, the Group has set up the first-ever chrome upgradation plant in Oman with a monthly ore processing capacity of 15,000 MT. The plant offers chrome ore concentrates of purity 38% and above. Having advantage over South African chrome concentrate in terms of Cr : Fe ratio, the product has been received very well by the end users.
The marble processing plant is equipped with the latest equipment from Italy. The Group produces unpolished and polished slabs as also polished tiles in different popular sizes. Production is 40,000 sqm per month.Currently, it operates three marble stone quarries and has a few more under development.
Omani marble has created a niche market for itself in all parts of the globe and it is known for its aesthetics and durability. Omani marble products go to China, India, USA, Europe, GCC and other South East Asian countries, to name a few.
GMG will start development of a large scale Laterite deposit; initial geology confirms a substantial iron ore deposit, with presence of Nickel and Cobalt being verified This a large scale greenfield site which will eventually support a substantial mining and refining operation with associated support infrastructure Low grade Iron Ore will initially be mined (~40%) with beneficiation driving production to ~60%.
The Ferrochrome plant was established in January 2015. The ferrochrome plant complements sequentially to processing the milled chrome ore produce from the mines and COB plant in Samail. The smelter focuses on the conversion of the raw chrome to high quality metal alloy pellets that have an elevated market value. Ferrochrome (Fe Cr) is an alloy of chromium and iron containing between 50% and 70% chromium. The ferrochrome is produced by electric arc melting of chromite, an iron magnesium chromium oxide and the most important chromium ore. The Plant covers a total area of 60,000 sq meters with additional space available for future expansions of about 40,000 sq meters. It has the capacity of 50,000 metric tons per year of pellets of ferrochrome which are exported to Eastern Asia markets, Western Europe and other countries.
Limestone chemically known as CaCo3, which is white in color, and sometimes accompanied by impurities such as clay, sand and iron oxides making it appear in different colors. It consists of sediments and aquatic organisms. As is the case for its geological nature that contains varying amounts of silica and varying amounts of pure limestone. In the company site there are two types of limestone ore. The first high quality with a purity of up to 99.5% , while the second type less purity up to 94%. The process of producing and extracting the limestone material is done by crushing to different sizes according to the use of the factories. For this purpose, a modern crusher with a capacity of 450 metric tons per hour was installed.
The demand for gypsum has been grows, mainly from cement and wallboard manufacturers. Gypsum from Oman exports expected to increase nearly double the present level, which will make it the fourth largest gypsum producing country. Currently 100,000Mt/Month of Gypsum ore is produced and exported from Salalah mines. GMG is considering building a gypsum wallboard plant in Salalah. The project is a part of future portfolio planned investments scheduled.
The group owns a high capacity, shallow-deposit Manganese mine: production is accelerating, with grades increasing following construction of a beneficiation plant. Gulf Mining Groups manganese deposit is very accessible; the ore body is exposed in many places: recovery is straightforward and grades are high. GMG has started the development and build of a beneficiation plant, which will increase the grade from 20 grade to 34-36 grade with 15,000 mt per month production.
Potassium Sulphate, or SOP, is considered a premium-quality potash Fertilizer and has two nutrients, Potassium and Sulphur. SOP is most commonly used on high-value crops like fruits, vegetables, nuts, tea and coffee. Estimated reserve in excess of 40 Million tons KCl. Production capacity estimated by 500ktpa and potential ramp up to 1mtpa. Capital Investment expected to be between $300m to $500m and expected to create 500 direct employment and a further 1000+ indirect.
A group outfit, commenced business in late 2007 and it handles the entire in-house logistical requirements of the group, besides catering to the needs of other importers and exporters in the Sultanate. GBSA is equipped to provide reliable, high quality logistics/ cargo services, customized to meet client requirements. GBSAs services include:
Gulf Mining Group also actively trades chrome ore, manganese ore, iron ore, rock phosphate, steel and aluminum scrap. It sources these products from Egypt, South Africa, North Africa, India, Australia and Europe and supply to China, India, UAE and few other countries. Gulf Mining also engages in trading and logistics of other metallurgical raw materials and products, ferrous and non-ferrous alloys, coke and coal.
The Sultanate of Oman has a wide variety of mineral resources. The Gulf Mining Group has mineral resources of the country and is working seriously to emerge as a leading player in Omans Mineral-based businesses.
and the Sultanate of Oman indicate that this region participated in the In the west of Abu Dhabi, exposures of terrestrial deposits and vertebrate fossils of Fossiliferous limestones and dolomites of late Permian to late. Cretaceous age ( ca.
85 Products View Limestone Powder offered by different companies, short-list and contact them The Limestone, we deal in, is sourced from the most reputed mines of We supply low silica limestone sourced from and Oman which are
11 Feb 2013 Oman's commerce and industry ministry has said licences will only be issued to mining The existing mining companies, such as limestone, that are exporting raw Monday, February 11 2013 at 05:11 UAE local time (GMT+4) List your company details for FREE in the region's biggest online directory
19 Jan 2012 The pending case against the Sultanate of Oman brought by investor Adel A Mr. Al Tamimi is a UAE native, naturalized citizen and real estate developer in agreements with the Oman Mining Company LLC (OMCO, a state -owned enterprise) related to a limestone quarrying/crushing operation.
19 Nov 2012 Today, in addition to mining large quantities of chrome ore, GMM is the only with the latest technology), limestone, iron ore, laterite, manganese, gypsum, The company's operations span Oman, UAE, Egypt, Turkey, Albania, South Until 2006, Oman was nowhere on that list of suppliers of chrome ore.
Only in the vicinity of the present-day Oman Mountains is there evidence of the marls of Oman and Abu Dhabi, the marly neritic limestones of the Gurpi Formation in offshore Iran, . sedimentary deposits until the end of Santonian times. Further A list of previously-published ages of Upper Cretaceous formations of the
19 Apr 2011 investment in establishing and operating a limestone quarry in the Jebel Wasa Agreement of Lease for Limestone Quarrying Project between Oman Mining Company and Emrock LLC, . business in Dubai, UAE, and a branch in Oman. .. I took the liberty to attach the list of pending permits and seek
reservoirs of Abu Dhabi, Oman, Qatar, and Saudi Arabia (Alsharhan, 1985a). made of the Lower Cretaceous limestones of the Thamama, now raised to group . List of previously published ages of Lower Cretaceous rock units in the Arabian Cretaceous deposits, lithological changes are relatively minor and can be
To unearth limestone, gypsum and marble, a mining and refining plant worth . jewellery produced from Omani metal were added to the list of trading goods. When compared to UAE or Kuwait, Oman's oil reserves and production is limited.
Building for Oman Botanic Garden. Busy times? construction in Abu Dhabi to the concrete structures of a cement plant in. Indonesia. sector and various mining initiatives.' The . policies have won us the Lloyd's List Global Safety. Award in
7 Jan 2011 I do not take credit for that in which is not mine. For a list of some of these great pioneers and heroes please see the bottom. Within the UAE/Oman you will find traditional climbing, sport climbing, top-rope climbing, bouldering and DWSing. The quality of limestone is also quite unique and diverse.
4 Jan 2012 Oman is a nation of three million people in the Middle East, A boundary agreement was reportedly signed and ratified with UAE in 2003 for .. asbestos, some marble, limestone, chromium, gypsum, natural gas early 1980s, the government built a $200-million copper mining and refining plant at Sohar.
LIST OF ACRONYMS. LIST OF FIGURES. .. Oman Biodiversity Strategy and the Convention on Biological Diversity. . UAE united Arab Emirates .. where the coasts are mainly sandy and interspersed with rocky limestone, 2) Limonium . Escalating sand mining activities or the demand for sand by new development
Oman's summer monsoon is locally known as 'Khareef'. ophiolites (oceanic crust, basalts, gabbro's and ultramafic rocks), capped by Tertiary limestones. . The inscription incorrectly lists the Baron Inverdale rather than Innderdale. Copper mine locations are also found at Sinfah (in south), Jabal Maythil (south central),
Calcium Carbonate (CaCO3), Gypsum (CaS04) and related minerals are the most common sources of calcium, an element used extensively in industrial processes, foods,and building materials. Target rocks for calcium-bearing minerals are extensive and include limestone, dolomite, marl,and chalk. Cement production facilitiesand other users of calcium and gypsum require high-purity product. Brukers analysis toolsempower mines to grade their products and certifyitsquality.
Puritycriteria, which is criticalfor grade controlfocuses oncalcium (Ca), magnesium (Mg), silicon (Si), aluminum (Al), iron (Fe),and potassium (K). X-rayfluorescencespectroscopy (XRF) is the most efficient and effective way to conduct purity analysis and grade limestone.
Portable and handheld energy dispersive XRF provide on-site instantaneous results for mine operations, exploration, core scanning,and excavation planning. The BrukerpXRFLimestone and Gypsum Calibrationis a matrix-matched calibration specifically designed for purity analysis.
Benchtopenergy dispersive XRFenables high-throughput sample analysis with either a XY autochanger or a carousel sample changer. Optional vacuum chamber enablesthe best performance for light elements on an ED-XRF.
Carbon and sulfur analysis by combustion provides critical information on the physical properties of limestone and dolomiteand are some of the most important measures for qualitycontrolof limestone ores. One of the most effective means for measuringC and S are with a SC combustion analyzer like theG4 ICARUS Series 2.In this CScombustion analyzersulfur is oxidized to SO2and carbon to CO2.TheG4 ICARUS Series 2isrobust and easy to use,deliveringfast and accurate carbon and sulfur resultsfrom the quarry to the cement kiln.
Once of the most common uses for limestone is in the production of cement. Bruker has closely partnered with the cement industry to develop unique solutions and focus on the strong integration of XRF, XRD, and FT-IT tools. Click below to explore Brukers solutions for the entire cement value chain.
Ordinary and water-resistant gypsum binders, synthetic gypsum and normal-weight and lightweight concrete can be applied for manufacturing. Blocks can be solid or hollow. A common size is 390190188mm. Compressive strength varies from 2.5 to 10MPa. Specific energy consumption for 1000 bricks (250 x 120 x 65 mm) made of ordinary gypsum concrete is 12.4kg of conventional fuel. For water-resistant gypsum concrete blocks, it is equal to 11.39kg; for gypsum concrete with its low water requirement, it is 7.89kg (Ferronskaya, 2004). According to Ferronskaya (2004), if equivalent power inputs on ordinary ceramic brick production will be accepted as 2504kWh per 1000 of conventional brick as 100%, power inputs on the manufacturing of gypsum blocks are less than 1%.
When comparing the thickness of masonry walls of equal heat resistance but made of different materials, gypsum-based block walls usually have a lower thickness than ordinary clay or sand-lime brick. Even at the same average density gypsum-based walls have lower thickness than walls made of other materials like hollow clay bricks, claydite cement concrete (Fig. 25.16).
One suggested method for manufacturing walling blocks is based on phosphorgypsum processing, which permits excluding the grinding process of the binder (Fig. 25.17). It is an energy-efficient method for producing items directly from phosphorgypsum, providing the implementation of two chemical processes: dehydration of dihydrate and hydration of hemihydrate in one technological cycle. At self-steaming in the high-density moulds, crystallised water releases in drip-liquid state and remains in the pores of grains and the voids of the gypsum. Blocks are pressed in moulds consisting of two punches and a formwork. The upper punch covers the gypsum powder placed in the formwork. With thermal treatment, the punch compacts the hydrated mass. The hardened product is demoulded at a temperature lower than 40C.
Fig. 25.17. Schematic circuit of phosphorgypsum direct-processing masonry units (grinding is excluded): Aggregate for phosphorgypsum modification (1); Pump (2); Continuously working autoclave (3); Filter (4); Mixing-activating equipment (5); Moulding machine (6); Masonry units (7).
Foam gypsum blocks can be produced with water-resistant binders or binders that are not water resistant. The blocks density varies from 300 to 900kg/m3 and a compressive strength from 1.5 to 10MPa. The most common size is 600300200mm. They are applied for partitions and internal walls.
A new method of building construction based on GFRG panels was developed in Australia and is widely used in Asian countries (Fig. 25.18). It combines the benefits of prefabricated, lightweight large panels with cavities, conventional cast-in-situ concrete and steel reinforcement, which require specific design methods (GFRG2, n/a; Wu, 2009).
Chapter 25 concludes that, because of an increase in demand, gypsum mining will also increase. However, demand will force the construction industry to use more synthetic, waste and recycled gypsum. In Europe, it is anticipated that by 2035, 25% of recycled gypsum will be used. It is also possible that new plants will be built in which products comprising 100% of recycled gypsum can be produced. Also, waste gypsum includes products such as flue gas desulphurisation (FGD) gypsum coming from desulphurisation processes. It is expected that the FGD waste will be used more in the future since many countries are opting to use a wet process in the coal power industry where fly ash and gypsum are fully separated.
The term coal combustion byproducts (CCB) includes fly ash, bottom ash, boiler slag, and FGD (flue-gas desulfurization) material known as synthetic gypsum. An American Society for Testing and Materials (ASTM) subcommittee under Committee E-50 on Environmental Assessment addressed the question of standards and definitions of coal and CCB terms. The definitions for some of the pertinent terms are as follows:
Bottom ash consists of agglomerated ash particleswhich are formed in pulverized-coal boilersthat are too large to be carried in the flue gases and adhere to the boiler walls or fall through open grates to an ash hopper at the bottom of the boiler.
FGD is the process of removing gaseous sulfur dioxide (SO2) from boiler exhaust gas. Primary types of FGD processors are wet scrubbers and dry scrubbers; sorbent injection is another primary process. SO2 sorbents include lime, limestone, sodium-based compounds, and high-calcium fly ash.
FGD material is the product of an FGD process that typically uses a high-calcium sorbent, such as lime or limestone. Sodium-based sorbent and high-calcium fly ash are also used in some systems. The physical nature of these materials varies from a wet, thixotropic sludge to a dry, powdered material, depending on the process. FGD units remove SO2 from flue gas but, in doing so, generate large quantities of synthetic gypsum (FGD material), which is a mixture of gypsum (CaSO4C2H2O), calcium sulfite (CaSO3), fly ash, and unreacted lime or limestone. A number of power plants convert the CaSO3 to calcium sulfate (CaSO4) by forced oxidation and take appropriate measures to reduce other impurities in the synthetic material and, thus, produce synthetic gypsum that meets or exceeds the specifications for wallboard manufacture. Wallboard plants that have been constructed adjacent to such electric utilities use the FGD gypsum from those electric utilities. About 26 metric tons (MT) of FGD material were produced in 2001, and about 7.3 MT (28%) were used, mostly for wallboard manufacture. FGD issues affect, directly or indirectly, coal, gypsum, lime, limestone, and soda ash industries. Increased commercial use of FGD products represents an economic opportunity for high-sulfur coal producers and the sorbent industry. Synthetic gypsum competes directly with natural gypsum as raw material for wallboard and cement manufacture.
The U.S. Geological Survey Minerals Yearbook publishes data based on industry surveys. The surveys conducted over the years account for about 60% of the power (highest survey response conducted in 2001). The last survey was conducted in 2001. Figures 2.1 and 2.2 were prepared using this information.
Figure 2.1 shows the relative amounts of CCBs generated across the country based on projections made by the U.S. Geological Services analysis. Figures 2.2 and 2.3 show the amounts of CCBs used and the fraction of this waste reused in industry applications, respectively.
The U.S. Energy Information Administration (EIA) has published an estimate that nearly half of the electricity generated in the United States comes from coal, resulting in about 130 million tons of CCB as of 2010. One source reports that about 55%, or 72 million tons, is fly ash and that about half the fly ash generated in the United States is currently used for beneficial purposes, mostly in concrete.2 This statistic is included as the 2010 data value in Figures 2.2 and 2.3. With the downturn in the economy and the lack of a peer-reviewed study to substantiate the claim, the reported estimate should not necessarily be considered accurate.
Figure 2.4 illustrates the industry general management practices in the handling of CCBs. Between 1966 and 2001, roughly 1.8 billion MTs of CCBs were generated. Of this amount, about 0.54 billion MTs was used in various industry applications (largely cement) and about 1.25 billion MTs sent to landfills or retained in ponds. Approximately 30% of the waste generated over this time period found use in value-added markets. Based on the 2010 reported value, a significant increase in use of this waste occurred in which 55% of the generated waste found its way into commercial markets.
Gypsum wall board, also known as plasterboard or drywall, is a plaster-based wall finish that is available in a variety of sizes; 4 feet wide by 8 feet high is the most common. Thicknesses vary in 1/8-inch increments from 1/4 to 3/4 inch.
The vast majority of the synthetic gypsum used by the industry is a byproduct of the process used to remove pollutants from the exhaust created by the burning of fossil fuels for power generation. Nearly 100 percent of the fiber used in the production of gypsum-board face and back paper comes from newsprint and postconsumer waste materials.
Advantages of gypsum board include: low cost, ease of installation and finishing, fire resistance, sound control, and availability. Disadvantages include: difficulty in curved-surface application and low durability when subject to damage from impact or abrasion.
Due to its ease of installation, familiarity, fire resistance, nontoxicity, and sound attenuation, gypsum wall board, known by its proprietary names Dywall and Sheetrock, is ubiquitous in construction. Gypsum wall board is a benign substance (basically paper-covered calcium sulfate), but it has significant environmental impacts because it is used on a vast scale; domestic construction uses an estimated 30 billion square feet per year.
The primary environmental impacts of gypsum are habitat disruption from mining, energy use and associated emissions in processing and shipment, and solid waste from disposal. Using synthetic or recycled gypsum board can significantly reduce several of these impacts. Synthetic gypsum accounts for approximately 20 percent of U.S. raw gypsum use and is made from the byproducts of manufacturing and energy-generating processes, primarily from desulfurization of coal-power-plant exhaust gases. In excess of 80 percent of coal fly ash sold in the U.S. is used in gypsum board.
Though synthetic gypsum-board use is growing in popularity, diverting drywall from the waste stream is proving more challenging. Reclaimed gypsum board can easily be recycled into new gypsum panels that conform to the same quality standards as natural and synthetic gypsum, but doing this may not be practical because gypsum is an inexpensive material that can require significant labor to separate and prepare for recycling. Gypsum-board face paper is commonly 100 percent recycled from newsprint, cardboard, and other postconsumer waste streams, but most recycled gypsum in wall-board products is postindustrial, made from gypsum-board manufacture. Gypsum board should be purchased in sizes that minimize the need for trimming (saving time and waste). Working crushed gypsum off-cuts (that have not been painted, glued, or otherwise contaminated) into soil helps reduce waste while improving the workability and calcium availability of many soils.
Also known as drywall or plasterboard, gypsum wall board is manufactured in the United States and Canada to comply with ASTM Specification C 1396. This standard must be met whether the core is made of natural ore or synthetic gypsum. Gypsum wall board is a plaster-based wall finish that is available in a variety of sizes; 4 feet wide by 8 feet high is the most common. Thicknesses vary in 1/8-inch increments from 1/4 inch to 3/4 inch.
Due to its ease of installation, familiarity, fire resistance, non-toxicity, and sound attenuation, gypsum wall board, known by its proprietary names Dywall and Sheetrock is ubiquitous in construction. Gypsum wall board is a benign substance (basically paper-covered calcium sulfate), but it has significant environmental impacts because it is used on a vast scale; domestic construction uses an estimated 30 billion square feet annually.
The main advantages of gypsum board include low cost, ease of installation and finishing, fire-resistance, sound control, and availability. Disadvantages include difficulty in applying it to curved surfaces, and low durability when subject to damage from impact or abrasion. Reclaimed gypsum board can easily be recycled into new gypsum panels that conform to the same quality standards as natural and synthetic gypsum, but doing this may not be practical because gypsum is an inexpensive material that can require significant labor to separate and prepare it for recycling. Gypsum board should be purchased in sizes that minimize the need for trimming (saving time and waste).
Gypsum board is the most common indoor building material in the United States. In the United States and Canada, gypsum board is manufactured to comply with ASTM Specification C 1396 which was designed to replace several existing ASTM specifications, leaving one reference standard for all gypsum board products. This standard is to be applied whether the core consists of natural ore or synthetic gypsum.
Gypsum wall board, also known as drywall, or plasterboard is a plaster-based wall finish that is available in a variety of standard sizes; 4ft wide by 8ft high is the most common. Thicknesses vary in 1/8-inch increments from 1/4 to 3/4inch. Gypsum wall board, which is also known by its proprietary names Drywall and Sheetrock, is ubiquitous in construction. Gypsum wall board is a benign substance (basically paper-covered calcium sulfate), but it has significant environmental impacts because it is used on a vast scale; domestic construction uses an estimated 30 billion square feet per year. Advantages of gypsum board include its low cost, ease of installation and finishing, fire resistance, nontoxicity, sound attenuation, and availability. Disadvantages include: difficulty in curved-surface application and low durability when subject to damage from impact or abrasion.
Gypsum board manufacturers are increasingly relying on synthetic gypsum as an effective alternative to natural gypsum. It is estimated that roughly 45% of the gypsum used by U.S. manufacturers in 2010 was of the synthetic variety. Synthetic gypsum and natural gypsum have similar general chemical compositions (CaSO42H20). The vast majority of the synthetic gypsum used by the industry is a by-product of the process used to remove pollutants from the exhaust created by the burning of fossil fuels for power generation. If synthetic gypsum was not used to manufacture gypsum panel products, it would end up in landfills.
Though synthetic gypsum-board use is growing in popularity, and reclaimed gypsum board can easily be recycled into new gypsum panels that conform to the same quality standards as natural and synthetic gypsum, doing this may not be practical because gypsum is an inexpensive material which can require significant labor to separate and prepare for recycling. Gypsum-board face paper is nearly 100% recycled from newsprint, cardboard, and other postconsumer waste streams, but most recycled gypsum in wall-board products is postindustrial, made from gypsum-board manufacture.
Ecology Action, a nonprofit environmental consultancy states that the main environmental impacts of gypsum include habitat disruption from mining, energy use and associated emissions in processing and shipment, in addition to solid waste from disposal. Some of these impacts can be significantly reduced by the use of synthetic or recycled gypsum board. Synthetic gypsum, which is now used in about 30% of drywall, is a by-product of coal-fired power plants. It is sometimes confused with fly ash another coal combustion product with which it has very little in common. In excess of 80% of coal fly ash sold in the United States is used in gypsum board.
New technologies have helped in the development of several new Gypsum board products that have come on the market and that are more environmentally friendly and superior in many ways to the traditional gypsum board. One such example is the new ecofriendly EcoRock Drywall which has significantly changed and improved the drywall product from its basic material elements to its production processing methods. EcoRock is a fully recyclable and highly attractive alternative. It is manufactured from 80% postindustrial recycling and exploits material from steel and cement plant waste and can be safely discarded in landfills. EcoRock is naturally cured and dried, which means that 80% less energy is required than the traditional methods use in the manufacturing process. Moreover, it contains no gypsum, thus eliminating the need for high-intense energy consumption during production and improves air quality by eliminating airborne mercury. EcoRock drywall, which creates 60% less dust, is resistant to termites and is 50% more resistant to mildew and mold.
According to the Gypsum Association,Gypsum board is the generic name for a family of panel products that consist of a noncombustible core, composed primarily of gypsum, and a paper surfacing on the face, back and long edges. Gypsum board is one of several building materials covered by the umbrella term gypsum panel products. All gypsum panel products contain gypsum cores; however, they can be faced with a variety of different materials, including paper and fiberglass mats.
Gypsum board is the generic name for a family of panel products that consist of a noncombustible core, composed primarily of gypsum, and a paper surfacing on the face, back and long edges. Gypsum board is one of several building materials covered by the umbrella term gypsum panel products. All gypsum panel products contain gypsum cores; however, they can be faced with a variety of different materials, including paper and fiberglass mats.
Gypsum wallboard, also known as plasterboard, or Drywall, is a plaster-based wall finish that is available in a variety of sizes. The standard size gypsum boards are 48 in. wide and 8, 10, 12, or 14 ft. long. The 48-in. width is compatible with standard framing methods in which studs or joists are spaced 16 in. and 24 in. o.c. Thicknesses vary in 1/8 in. increments from 1/4 in. to 3/4 in. It differs from other panel-type building products, such as plywood, hardboard, and fiberboard because it contains a noncombustible core and paper facers. When used in interiors, joints and fastener heads are covered with a joint compound system, thereby creating a continuous surface suitable for most types of interior decoration. A typical board application is shown in Figure6.5a.
The vast majority of the synthetic gypsum used by the industry is a by-product of the process used to remove pollutants from the exhaust created by the burning of fossil fuels for power generation. Nearly 100% of the fiber used in the production of gypsum board face and back paper comes from newsprint and postconsumer waste materials.
Advantages of gypsum board include low cost, ease of installation and finishing, fire resistance, sound control, and availability. Disadvantages include difficulty in curved surface application and low durability when subject to damage from impact or abrasion.
Because of its ease of installation, familiarity, fire resistance, nontoxicity, and sound attenuation, gypsum wallboard, known by its proprietary names Drywall and Sheetrock, is ubiquitous in construction. Gypsum wallboard is a benign substance (basically paper-covered calcium sulfate), but it has significant environmental impacts because it is used on a vast scale; domestic construction uses an estimated 30 billion ft.2/year.
The primary environmental impacts of gypsum are habitat disruption from mining, energy use, and associated emissions in processing and shipment, and solid waste from disposal. Using synthetic or recycled gypsum board can significantly reduce several of these impacts. Synthetic gypsum accounts for approximately 20% of US raw gypsum use and is made from the by-product of manufacturing and energy-generating processes, primarily from desulfurization of coal power plant exhaust gases. In excess of 80% of coal fly ash sold in the United States is used in gypsum board manufacturing.
Synthetic gypsum, which is now used in about 30% of drywall, is a by-product of coal-fired power plants and comprises about 95%, by weight, of American Gypsum wallboard. American Gypsum say it is processed almost identically as you would natural gypsum rock. Though synthetic gypsum board use is growing in popularity, diverting drywall from the waste stream is proving more challenging. Reclaimed gypsum board can easily be recycled into new gypsum panels that conform to the same quality standards as natural and synthetic gypsum, but doing this may not be practical because gypsum is an inexpensive material but can require significant labor to separate and prepare it for recycling. Gypsum board face paper is commonly 100% recycled, from newsprint, cardboard, andother postconsumer waste streams, but most recycled gypsum in wallboard products is postindustrial from gypsum board manufacture. Gypsum board should be purchased in sizes that minimize the need for trimming (saving time and waste). Working crushed gypsum off cuts (that have not been painted, glued, or otherwise contaminated) into soil helps reduce waste while improving the workability and calcium availability of many soils.
Normally, synthetic gypsum has lower trace metal content then what is typically found in residential soil standards. Synthetic gypsum wallboard products by American Gypsum, for example, are just as safe as natural gypsum and are certified as low-VOC products by the GREENGUARD Environmental Institute.
Siding is an external protection element that provides protection for wall systems from moisture and the heat and ultraviolet radiation of the sun. Selecting siding that is reclaimed, recyclable, and biodegradable in a landfill or incorporates recycled material are key considerations that will reduce waste and pollution. Maintenance, too, is an important consideration. High-maintenance materials requiring regular upkeep, such as repainting, and use additional resources and energy over their life cycle are less sustainable. There are many types of siding, and the environmental impacts of siding products vary considerably.
Considerations: Earth or lime plasters last a long time and require relatively little maintenance. Cement or lime is commonly added for improved hardening and durability, but the comparatively small (or zero) overall cement content of natural plasters means the material causes relatively small amounts of pollution and energy use to prepare and install. Deep eaves or overhangs that protect the siding from extended moisture exposure are critical to the longevity of natural plasters.
Fiber-cement siding has proven to be very durable, and many products are backed by 50-year or lifetime warranties. It is fire and pest resistant and emits no pollutants in use. However, it possesses a high embodied energy because of its cement content and because it is manufactured with wood fiber from overseas.
Cement stucco is another extremely durable material that helps minimize long-term waste, but cement is also energy intensive to manufacture. Cement substitutes such as fly ash or rice hull ash can mitigate the environmental cost of stuccos. In coastal regions, salt spray can accelerate corrosion of reinforcing meshes.
Metal siding is very durable, recyclable, and typically contains significant postconsumer recycled content. It is energy intensive to manufacture, but recycled steel and aluminum require far less energy than virgin ore. Some types of metal siding are prone to being easily damaged.
Composite siding (hardboard) is made of newspaper or wood fiber mixed with recycled plastic or binding agents. It is highly durable, resists moisture and decay, often has significant recycled content, and is not prone to warping or cracking like wood. Composites require less frequent repainting and some need not be painted at all, saving waste and resources.
Wood siding requires more maintenance than many of the other siding options, but it is renewable and requires relatively little energy to harvest and process. If it is not well maintained, wood can easily be the least durable option, generating significant waste. The most durable solid wood siding comes unfortunately from old growth and tropical forests.
Siding selection considerations:a.The most durable siding product that is appropriate should be selected. Siding failures that allow water into the wall cavity can lead to expensive repairs, the waste of damaged components, and the environmental costs of replacement materials. Fire resistance is a feature that helps reduce the financial and environmental impact of rebuilding, particularly in high-risk areas.b.For existing buildings, consider refinishing existing siding to minimize waste, pollution, and energy use.c.Select materials that are biodegradable, have recycled content, and/or are recyclable.d.Reclaimed or remilled wood siding should be used to minimize demand for virgin wood and reduce waste (painted wood should be tested for lead contamination prior to use).e.New wood siding should display an FSC-certified products label.f.Vinyl is somewhat durable, but it is not a green building material. Attributed disadvantages include pollution generated in manufacturing, air emissions, human health hazards of manufacturing and installation, the release of dioxin and other toxic persistent organic pollutants in the event of fire, and the difficulty recycling.
The most durable siding product that is appropriate should be selected. Siding failures that allow water into the wall cavity can lead to expensive repairs, the waste of damaged components, and the environmental costs of replacement materials. Fire resistance is a feature that helps reduce the financial and environmental impact of rebuilding, particularly in high-risk areas.
Vinyl is somewhat durable, but it is not a green building material. Attributed disadvantages include pollution generated in manufacturing, air emissions, human health hazards of manufacturing and installation, the release of dioxin and other toxic persistent organic pollutants in the event of fire, and the difficulty recycling.
More than 100 million tons of coal-related residues are generated annually by coal-burning plants [24,25]. These materials have many namesthey are referred to as fossil fuel combustion wastes (FFCWs) by the U.S. Environmental Protection Agency (EPA); as coal combustion products (CCPs) by the utility industry, ash marketers, and ash users; and as coal combustion by-products (CCBs) by the U.S. Department of Energy and other federal agencies. These residues become products when utilized and wastes when disposed of . They include fly ash, bottom ash, boiler slag, and flue gas desulfurization (FGD) material (i.e., synthetic gypsum). The fly ash is the fine fraction of the CCBs that is entrained in the flue gas exiting a boiler and is captured by particulate control devices. Bottom ash is the large ash particles that accumulate at the bottom of a boiler. Boiler slag is the molten inorganic material that is collected at the bottom of some boilers and discharged into a water-filled pit where it is quenched and removed as glassy particles. FGD units, which remove sulfur dioxide using calcium-based reagents, generate large quantities of synthetic gypsum, which is a mixture of mainly gypsum (CaSO4) and calcium sulfite (CaSO3) but which can also contain fly ash and unreacted lime or limestone [24,25]. In 2000, CCB production in the United States was 108,050,000 short tons and was comprised of :
In the United States, approximately 30% of the CCBs are used in a variety of applications, with the remainder being disposed of . The components of the CCBs have different uses because they have distinct chemical and physical properties that make them suitable for specific applications. CCBs are used in cement and concrete; mine backfill, agriculture, blasting grit, and roofing applications; waste stabilization; wallboard production; acid mine drainage control; and as road base/subbase, anti-skid material, fillers, and extenders [24,25].
Globally, CCB use varies significantly. In Europe, more CCBs are used than in the United States; for example, in 1999, 56% of the CCBs were profitably used in Europe compared to about 30% in the United States . The CCBs are used in a number of applications, primarily in concrete, portland cement manufacture, and road construction. Raw materials shortages and favorable state regulations account for higher usage in Europe than in the United States. Countries such as Canada, India, and Japan utilize 27, 13, and 84% of their CCBs, respectively . Canada's usage is similar to that of the United States, CCB usage in India is low due to the relatively large amount of CCBs produced because of the coal's high ash content, and Japan utilizes most of its CCBs due to the high cost of disposal in Japan.
Coal combustion by-products primarily contain elements such as iron, aluminum, magnesium, manganese, calcium, potassium, sodium, and silica, which for the most part are innocuous. CCBs also contain small amounts of trace elements such as arsenic, barium, beryllium, cadmium, cobalt, chromium, copper, nickel, lead, selenium, zinc, and mercury. These elements can be classified as essential nutrients, toxic elements, or priority pollutants and are considered to have some environmental or public health impacts . The risks include potential groundwater contamination of trace elements and above-ground human health impacts through inhalation and ingestion of contaminants released through wind erosion and surface water erosion and runoff .
The Resource Conservation and Recovery Act (RCRA) has been the primary statute governing the management and use of CCBs. The EPA was considering some form of Subtitle C regulation (i.e., classify CCBs as hazardous wastes) under the RCRA for CCBs used in mine backfill or for agricultural applications ; however, the agency investigated the dangers of CCBs to human health and the environment and concluded that CCBs do not pose sufficient danger to the environment to warrant regulations under RCRA Subtitle C. The EPA does intend to develop national regulations under RCRA Subtitle D (nonhazardous solid waste) or to work with the U.S. Department of the Interior toward modifying existing regulations under the SMCRA when CCBs are placed in landfills or surface impoundments or are used as fill in surface or underground mines .
In recent years, there has been an interest in the use of gypsum as a sustainable mineral binder. Therefore, Chapter 25 is concerned with the utilisation and sustainability of gypsum-based construction materials. The chapter begins with a general introduction about the gypsum (composition, manufacturing, setting). Then the different types of gypsum products are described, including the global production of gypsum, the raw materials of natural and synthetic gypsum, chemical composition, dehydration and details on the manufacturing of -hemihydrate, anhydrate, phosphogypsum, flue gas desulphurisation (FGD) gypsum and fluorgypsum. Some figures on the energy consumption and emission of gypsum binders are then presented. This section is followed by describing the reactions of hydration and the heat produced during reaction for different gypsum products and hardening. The mechanical properties (eg, compressive strength) and durability (eg, fire resistance) of gypsum-based binders are highlighted. The different products/composites made with gypsum (including waste gypsum) as binding materials are outlined (eg, masonry/concrete units) with more description of gypsum boards and panels, decorative elements as well as other products. One section is dedicated to sustainability aspects of gypsum-based products, including embodied energy and carbon footprint and reusing and recycling. The final two sections focus on life-cycle assessment and future trends.
Reverse osmosis (RO), nano-filtration (NF) and ultra-filtration (UF) membranes have long been used in the desalination industry to treat seawater and brackish water. However, as the global population increases, making more fresh, clean water available is imperative. Thats why Genesys International has turned its expertise to providing antiscalants and cleaners to a less traditional industry mining.
According to a 2012 article by Paulina Szyplinska, mining is the fourth largest consumer of water worldwide, but 90% of minewater is recyclable using technologies such as RO or NF. Although this is still a comparatively new application of water filtration membrane technology, the number of plants associated with mining operations has increased dramatically over the past 10 years.
There is a specific challenge that affects minewater filtration plants high levels of total dissolved solids (TDS), which leads to a strong tendency for scale to form, especially calcium sulphate (CaSO4) or gypsum.
These conditions fall outside membrane manufacturers recommended operating parameters. For that reason, the membrane technology industry has traditionally dismissed the mining sector as a source of business, considering it just too challenging to be worthwhile.
However, despite that, it seems that mining operators are increasingly investing in RO and NF membrane filtration, attracted by the benefit of enhanced metal recovery as well as the ability to clean up wastewater. Through Genesys Internationals own research, it has identified as many as 389 mines currently using membrane filtration, 301 of them commissioned since 2009.
The company believes that, with the right chemistry and an open mind, its possible not only to inhibit complex scale but also to clean fouled and scaled membranes effectively to restore their performance. And it seems like others are beginning to catch on. The team at Genesys were recently encouraged to see the following comments in a paper by Darryl Butcher, director of BDB Process, Australia, regarding two membrane plant projects he had been involved with in Africa: Neither of these applications operated the chosen membranes within the recommended operating windows published by the manufacturers, but both were technically and commercially, very successful and both exceeded the forecast performance used to justify the project capital expenditure It appears likely that membranes will be applied in a broad range of applications to improve process outcomes.
Unlike other types of scaling, CaSO4 is pH independent. That means that the addition of an acid or alkali will have no effect in preventing scale formation. Genesys has developed two new antiscalants Genmine AS26 and Genmine AS65 which are capable of inhibiting CaSO4 at both low and high pH (up to x8-10 saturation levels).
Genmine AS26 is particularly resilient to acidic conditions, which is rare for an antiscalant. Formulated and perfected through rigorous testing, it can inhibit CaSO4 at pH values as low at 1-2 (Fig. 1). This means that no costly pre-treatment is needed to neutralise mining effluent for the antiscalant to work. That should result in CAPEX and OPEX savings, while making it even more feasible to reclaim both metals and clean water from tailings waste.
Of course, not all minewaters are acidic, which is why the firm has also developed Genmine AS65, which is capable of inhibiting CaSO4 scale at saturation levels of x8-10 (Fig. 2) at neutral and alkaline pH values. This is particularly relevant for the alkaline cyanide heap leach processes, where membranes are used to concentrate both pregnant and barren liquors. By providing products specific to both acidic and alkaline minewaters, the company is able to provide the right chemistry for potentially any minewater that is affected by gypsum scale.
If gypsum scale has already built up, perhaps due to using ineffective antiscalants or dosing inappropriately, removing it without damaging the membrane is challenging, but not impossible. This should be done as promptly as possible to prevent the scale itself causing irreversible damage to the membrane surface.
CaSO4 scale initially forms needle-like particles. It can then go on to form platelets and rosettes, which can damage the membrane surface through abrasion. This will ultimately lead to indents and holes in the surface, affecting the membranes salt rejection properties and increasing its flux (allowing more ions to pass though).
The correct pre-treatment and effective use of our specialist antiscalants will drastically reduce scaling. However, if feed conditions are constantly changing or if, at some point, the saturation limit of the antiscalant is exceeded, scale will still form.
Following extensive research, Genesys has developed three new cleaning products specifically designed to address these issues: Genmine C07 (neutral pH) and Genmine C15 and Genmine C17 (high pH). All three have shown great promise in CaSO4 removal, vastly outperforming traditional cleaners in testing.
A heavily scaled Vexar spacer was weighed before and after cleaning, with the differential between weights giving an insight to the cleaners performance. After a three-hour clean, Genmine C17 removed 99.3% of scale, Genmine C15 removed 96.5% and Genmine C07 removed 93.3%.
The dosing of membrane chemicals is particularly sensitive in the challenging conditions created by minewater. One tool that can assist here is Membrane Mine Master (MMM) software, developed specifically to predict the appropriate antiscalant dosing for RO, NF or UF membrane plants used to filter minewater. This new software breaks the rules of conventional scale prediction software by functioning across the pH range (1-14), while most are limited to a narrow pH range, typically 5-9.
Genesys recognised the need to provide better support for the mining community and rose to the challenge. Its specialist antiscalants can prevent the formation of CaSO4 scale at saturation levels up to 8-10 times normal solubility, across the whole pH range, without additional pre-treatment and its dedicated cleaning products are capable of completely removing gypsum scale, restoring membrane plant performance, provided they are used soon enough.
The Membrane Mine Master software can help operators work out the appropriate antiscalant and dose rates to keep scale at bay and reduce the costs associated with pre-treatment and disposal of wastewater.
In addition to the range of CaSO4 specific products, the company offers antiscalants to prevent silica, calcium carbonate, barium sulphate and metal deposits commonly encountered in mining. It also offers a range of cleaning products to tackle fouling with clay, iron and other metals and organics, including biofilm.
The Sultanate of Oman, is an Arab country in the southeastern coast of the Arabian Peninsula. Holding a strategically important position at the mouth of the Persian Gulf, the nation is bordered by the United Arab Emirates (UAE)to the northwest, Saudi Arabia to the west, and Yemen to the southwest, and shares marine borders with Iran and Pakistan.
Oman is a nation well-endowed with natural mineral resources, concentrated mainly in its 700-km by 150-km mountain range, which offers an exposed ophiolite geological outcrop containing minerals such as copper, gold, silver, chromite,lead, nickel, manganese and zinc. Other regions in the sultanate are blessed with deposits of dolomite, limestone, gypsum, silica, cobalt, marble and iron.
Not only does mining contribute to GDP, it also acts as a catalyst for the growth of other core industries like power, steel, cement, etc., which are critical for the overall development of the economy.Get in Touch with Mechanic