Natural or synthetic zeolites are microporous crystalline aluminosilicates,built up of 3-dimensional frame of [SiO4]4- and [AlO4]5-. Zeolites have unique ion exchange and sorption properties. They are widely used in wastewater treatment, construction, act as catalyst, gas separation and ion exchange in industry.
Water treatment
Zeolites are used in large number of water treatment such as water softening and purification from ammonia, heavy and radioactive metals. Besides that, zeolites are used as absorbents to remove of organic substances, microorganisms and anions, for seawater desalination membranes and fill materials for reactive permeable barriers. Wastewater contains trace amount of heavy metals such as Zn, Cr, Pb, Cd, Cu. These heavy metals need to be removed because they cause serious environmental problem. Heavy metals are removed along with other technologies including chemical precipitation, ion exchange, adsorption, membrane filtration, coagulation flocculation, flotation and electrochemical methods.
Natural zeolites have shown good ion-exchange capacities for cations, such as ammonium and heavy metal ions. In order to have high adsorption capacity for organic matter and anions, modification of natural zeolites can be performed by several methods, such as acid treatment, ion exchange, and surfactant functionalization. Besides the removal of heavy metals, natural zeolites are used to to remove ammonia and humic acid from the suface waters. The removal of the contaminants depends on pH value, initial concentration of humic acid and ammonia, temperature and contact time. Zeolite shows best performance of ammonia and humic acid removal at the pH close to natural water. Furthermore, natural and modified zeolites are used t...
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... to produce construction materials. More than 60% of the world's zeolite production is consumed by the construction industry in China in order to make high performance and lightweight concrete.
Zeolite can be expanded by heating to around 1200ºC to produce lightweight aggregate with a density of around 0.8 kg/cm3. With such properties, zeolite can be used to make lightweight blocks for construction, or decorative wall panels for example.
The porous structure of natural zeolite enable to holds water which can increase curing time and increase strength during curing. Zeolites also have much higher cation exchange capacities than other natural pozzolans in which prevents the alkali-silica reaction.
Natural zeolite can also be used to make ceramics, glazes and frits. However, the full potential of zeolites in the ceramics industry has yet to be realized
As shown in Fig. 5, the final pH of the NaClO-NH3 solution after simultaneous removal are 5.4, 6.9, 7.2, 7.5, 8.5, 9.6, 10.7, 11.5 and 12.8 with respect to the initial pH of 5, 6, 7, 8, 9, 10, 11, 12 and 13, from which, an interesting law can be concluded as that if the initial pH is an acidic, the final pH is slightly increased; but if the initial pH is an alkaline, the final pH is declined. NaClO-NH3 is macromolecule compounds with a large inter surface area. It contains abundant functional groups such as hydroxyl (OH), carboxyl (COO), quinone, amino (–NH2), etc, which determines that NaClO-NH3 is a salt of strong base and weak acid, as well the ionization equilibrium and hydrolytic equilibrium would be complicated. When the pH of the NaClO-NH3 solution was acidic, the functional groups such as OH, COO and NH2- would react with H+ to generate the NH3 sediment, resulting in a decrease of inter surface area owing to the block and a great loss of NaClO-NH3, then the NOx removal as well as the duration time was decreased. As for the increase of the final pH in the acidic conditions, this was a result of the consumption of H+ by NaClO. The decrease of the
As tetragonal phase has high toughness and high strength, additional stabiliser such as Yttria can maintain the tetragonal phase of zirconia at low temperature. However, degradation gradually happens in Y-TZP after a certain years, especially under hydrothermal condition.
Quartzite is a non-foliated metamorphic rock. This rock is intrusive and forms when exposed to extreme amounts of heat and pressure. Over a billion years ago, there was an ocean where Kamiak Butte is. This ocean floor was made of sand, as time went on oceans receded and the exposed sand underwent processes that turned it into sandstone – or as we learned in class the process of lithification. Years later, this sandstone would morph into the quartzite that is present now.2
Procedure: A sand bath was set atop a hot plate set at power level 5, while a 10 mL round bottom was prepared with the addition of 14 (0.33 mL) drops of olive oil and 1 mL of cyclohexene. Once the contents of the 10 mL round bottom were mixed thoroughly, a boiling chip was added, and the round bottom was attached to a reflux condenser apparatus. The reflux was run for 20 minutes starting at the point in time when the mixture within the round bottom flask (that was submerged in the heated sand bath) began to boil. While the running the reflux, a 5 ¾ inch Pasteur pipette was obtained and clamped vertically with the tip facing downward. A small amount of glass wool was placed inside of the pipette and pushed down to block the narrowing end by a wooden boiling stick. A total of 100 mg (0.100 g) of celite was weighed out and was carefully added into the pipette as an additional layer atop the glass wool stopper.
In the first part of this project, two cation elimination tests and one cation confirmation test were performed. 10 drops of 4 cation solutions: potassium, zinc(II), copper(II)
Adding 25 g of Zink to HCl in an open flask did not cause an explosion. The maximum temperature of the reaction reached 100°C. Total weight of the container decreased from 103 g to 94.93 g.
Thin film coatings of ceramic materials are widely used to safeguard materials against corrosion, wear resistance, and thermal conductivity [1, 2]. The objective of this work is to increase the thermal resistivity and thereby improve the mechanical properties of the materials. In this work thin film of Ceria stabilized Zirconia was formed and is applied on the area where the heat transfer occurs the most and is used to reduce its effect of temperature. These coatings are used to protect parts from big and prolonged heat loads by utilizing thermally insulated materials which can undergo a significant temperature difference between the initial material and the coating surface [3]. Many new materials have been developed, but steel remains the principal construction material for automobiles appliances, and industrial machinery. Since steels are vulnerable to aggressive chemical environments or atmospheric oxidation, metal coating is necessary to provide various degrees of protection through hot-dipped and electroplating process to tough polymers and flame-sprayed ceramics. In general corrosive atmospheres contain more than one active material, and the coating must resist dissemination by a combination of oxidizers, solvents, or both. Thus, the best hurdle is one that resists corrosion [4]. The obligatory thin films have been attained by using spray pyrolysis coating method. Spray pyrolysis technique involves spraying of a solution containing soluble salts of the desired compound on to preheated substrates, where the constituents react to form a chemical compound [8, 9]. Both, dense and porous structures can be deposited by spray pyrolysis which can also be achieved on large substrates by scaling up the equipment. It has capability to...
Fundamental studies by Stober [ ], Meyer and Heckerman [ ] , and Bering and Serpinskii [ ] indicate that silica surface consists of siloxane network in the bulk, while the hydroxyl groups are attached onto silicon atoms. However these groups are not equivalent in their adsorption or reaction behavior. Fig 1a represents a general arrangement on a silica surface. Belyakova et al. identifies that the number of hydroxyl (Silanol) group on different type of silica surfaces are same i.e. 4 -5 SiOH groups per nm2. Lange [ ] identifies that water associates with these silanol groups in two ways, by hydrogen bonding or by physically adsorbed. Dalton and Iler [ ] states that there is at least a monolyer of water immobilized on silanol groups due to hydrogen bonding, this “glassy layer” protects underlying silica network from foreign molecules. Klier and Zettlemoyer [ ] indicates that water sat “oxygen down” on silanol groups. De Boer and Vleeskens [ ] argued that around 120 oC in ambient air silica looses adsorbed water unless it is present in micropores which would otherwise tak...
Obtaining Zinc Oxide from Calamine Introduction Calamine is a mineral containing zinc carbonate (ZnCO₃) On heating it decomposes as: [IMAGE]ZnCO₃ ZnO + CO₂ (C = 12, 0 = 16, Zn = 65) This equation allows you to calculate a theoretical conversion of calamine into zinc oxide. As when using the theoretical conversion; [IMAGE]ZnCO₃ ZnO + CO₂ [IMAGE]65+12+48 65+16 + 12+32 [IMAGE]125 81 + 44 This means that one mole of calamine weighs 125g and when heated it produces 81g of zinc oxide and 44g of carbon dioxide. Therefore to work out how much zinc oxide is produced from 1g of calamine we divide 81 by 125.
...y comes from the Balcones Escarpment. Larger crushed rock from this area is used as a base layer for roads and buildings, to protect them from the shifting soils. Very pure limestone is procesed into lime, wich is then used in a wide variety of agricultural, industrial, and construction activities. Other rocks crushed for building materials include basalt, used for railroad track beds, and marble, used for fancy terrazzo floors.
Given that aluminum is the third most abundant substance as well as the most prominent metal in the Earth’s crust, repurposing it is beneficial to everyone. There are multiple ways to repurpose aluminum, however, a prominent method is converting aluminum into alum. While alum can be naturally occurring in areas of heavy weathering, that oxidize sulfide, and include potassium bearing minerals all occur, it can also be synthesized as shown in this experiment. By synthesizing alum, many practical applications arise. Medicinally, alum can be utilized to stop bleeding in minor cuts, as a treatment for gingivitis and gum bleeding, as well as a preservative for pickling fruits and vegetables. On a larger scale, alum can be used in flocculation to treat dirty water to make it drinkable. In this case, the alum binds to the heavier particles in the water, such as dirt and sand, and causes them to sink to the bottom of the container. Next, a simple filtering would need to be done to render the water
Kaolin is the major primary clay which is used in ceramics. The use of the name "kaolin" for a clay body encompasses more than a body composed of pure kaolinite crystals, however, according to Rhodes, the composition of kaolin clays generally fall with in the bounds of kaolinite's composition: 46%silica, 39% alumina, 13% water (Rhodes p. 47). Kaolinite has the most basic 1:1 tetrahedral-octahedral clay structure, and maintains a simple and pure composition. So when kaolin is fired along with some silica and feldspar, it forms a highly refractory white solid. As the main ingredient in porcelain, Kaolin comprises, on average, about 50% of a porcelain mixture.
The U.S. Geological Survey suggested that if the global economic trend of depleting resources continues, then resources such as iron would deplete in a matter of sixty years. Further, iron prices will increase exponentially within the timeframe. Fortunately, iron is found in a prevalent phase that occurs within several minerals with different crystal structures. These minerals—Kamacite, Taenite, and Tetrataenite—can be formed by several different process, including igneous crystallization and reduction of oxides...
Fertilizers from both natural and manufactured sources can also contribute to water pollution. Soluble-nitrogen forms can leach into groundwater, and all fertilize...
As pigment and extender, China Clay it is used extensively in the paper and paints industry. As filler, it is used in the manufacture of plastics, detergents, rubber goods and paper; as raw material, it is used by glass and ceramic industries for making fiberglass and porcelain respectively.