Calcium silicate carbonates

Antimony trioxide Calcium silicate Carbon Cellulose Dolomite... 

Calcium monocarbonate Calcium silicate Carbon Carbon black Cellulose... 

Additives used in final products Fillers calcium silicate, carbon fibers, glass fibers, graphite flakes, mica, multiwalled carbon nanotubes, titanlun dioxide Plasticizers pentaerythrltotetrabenzoate ester Antistatics fatty quaternary ammonium compounds, potassium titanate whisker Release fatty acid amide, p-tallow toluenesulfon-amlde, pentaerythrltol tetrastearate, polyolefin ... 

Goto, S., K. Suenaga, T. Kado and M. Fukuhara (1995). Calcium silicate carbon-ation products ./o r a/ of the American Ceramic Society 78(11) 2867-2872. 

Boron carbide from boron oxide and carbon Calcium silicate from lime and silica Calcium carbide by reaction of lime and carbon Leblanc soda ash... 

For equivalent particle size the carbon blacks are the most powerful reinforcing fillers. However, fine particle size silicas can be very useful in non-black compounds whilst other fillers such as aluminium hydroxide, zinc oxide and calcium silicate have some reinforcing effect. 

The usual extraction procedure is to roast the crushed ore, or vanadium residue, with NaCl or Na2C03 at 850°C. This produces sodium vanadate, NaV03, which is leached out with water. Acidification with sulfuric acid to pH 2-3 precipitates red cake , a polyvanadate which, on fusing at 700°C, gives a black, technical grade vanadium pentoxide. Reduction is then necessary to obtain the metal, but, since about 80% of vanadium produced is used as an additive to steel, it is usual to effect the reduction in an electric furnace in the presence of iron or iron ore to produce ferrovanadium, which can then be used without further refinement. Carbon was formerly used as the reductant, but it is difficult to avoid the formation of an intractable carbide, and so it has been superseded by aluminium or, more commonly, ferrosilicon (p. 330) in which case lime is also added to remove the silica as a slag of calcium silicate. If pure vanadium metal is required it can... 

Elemental phosphorus is prepared by the reduction of calcium phosphate, Ca3(P04)o, with coke in the presence of sand, SiO>. The products are phosphorus, calcium silicate, CaSiOa, and carbon monoxide. 

Since the reactions (15), (16), and (17) require successively higher temperatures, the blast furnace temperature is kept highest near the bottom of the furnace. Near the bottom, the temperature, is sufficiently high that the impure iron—saturated with carbon—collects there as a molten liquid. The slag, which is mainly calcium silicate, CaSi03, removes any sand in the ore through reaction with limestone, CaC03. 

Other anticaking ingredients include ferric ammonium citrate, silicon dioxide, sodium ferrocyanide, magnesium silicate, magnesium carbonate, propylene glycol, aluminum calcium silicate, sodium aluminosilicate (also called sodium silicoaluminate), and calcium phosphate. 

Self-Test L.2B Carbon dioxide can be removed from power plant exhaust gases by combining it with an aqueous slurry of calcium silicate 2 C02(g) + H,0(l) + CaSiOds) — Si02(s) + Ca(HC03)2(aq). What mass of CaSiO, (having molar mass 116.17 g-mol ) is needed to react completely with 0.300 kg of carbon dioxide ... 

Alternatives to fossil fuels, such as hydrogen, are explored in Box 6.2 and Section 14.3. Coal, which is mostly carbon, can be converted into fuels with a lower proportion of carbon. Its conversion into methane, CH4, for instance, would reduce C02 emissions per unit of energy. We can also work with nature by accelerating the uptake of carbon by the natural processes of the carbon cycle. For example, one proposed solution is to pump C02 exhaust deep into the ocean, where it would dissolve to form carbonic acid and bicarbonate ions. Carbon dioxide can also be removed from power plant exhaust gases by passing the exhaust through an aqueous slurry of calcium silicate to produce harmless solid products ... 

The iron formed in a blast furnace, called pig iron, contains impurities that make the metal brittle. These include phosphorus and silicon from silicate and phosphate minerals that contaminated the original ore, as well as carbon and sulfur from the coke. This iron is refined in a converter furnace. Here, a stream of O2 gas blows through molten impure iron. Oxygen reacts with the nonmetal impurities, converting them to oxides. As in the blast furnace, CaO is added to convert Si02 into liquid calcium silicate, in which the other oxides dissolve. The molten iron is analyzed at intervals until its impurities have been reduced to satisfactory levels. Then the liquid metal, now in the form called steel, is poured from the converter and allowed to solidify. 

Hydrated calcium silicate minerals such as xonotlite, truscottite, and gyrolite are rare but have been reported from several Au-Ag deposits. They do not coexist with Au-Ag minerals but instead are found with quartz, carbonates, and johannsenite. However, in the Keisen No. 3-2 vein in the Hishikari Au-Ag deposits, a close association of electrum with truscottite, smectite and calcite is observed (Imai and Uto, 2001). 

The metal chlorides normally used as chlorinating agents are the low-cost reagents sodium chloride and calcium chloride. Silicates, carbonates and sulfates can be chloridized... 

Calcium silicate Colloidal silicon dioxide Magnesium carbonate Magnesium trisilicate Starch Talc... 

Silver white, relatively soft metal that is only applied in alloys. Oxygen and water attack pure Ca. The most prominent compound is the oxide (CaO) = burnt calcium, which hardens to calcium carbonate in mortar. Annual production of about 120 million tons. Burnt gypsum (CaS04 0.5 H20) hardens with water. A great step in evolution was the replacement of hard shells of brittle calcium carbonate by an internal skeleton of tough calcium phosphate (hydroxylapatite)-protein composite. Calcium is essential for all life forms. The daily requirement is 0.7-1.0 g. Humans (70 kg) contain 1 kg of calcium. Calcium silicate is the main component of cement. Marble is calcium carbonate in polycrystalline form and the favorite material of sculptors. 

This reaction is similar to Eq. 21.8. Wollastonite is an example of a calcium silicate mineral produced by the metamorphosis of detrital biogenic calcium carbonate and BSi. 

As the rock cycle continues, the calcium silicate minerals are eventually uplifted onto land where they imdergo chemical weathering. This reaction involves acid hydrolysis driven by carbonic acid. The latter is derived from the dissolution of the magmatic CO2 in rainwater ... 

Then the roasted ore is combined with sand, powdered limestone, and some unroasted ore (containing copper(II) sulfide), and heated at 1,100°C in a reverberatory furnace. Copper(II) sulfide is reduced to copper(I) sulfide. Calcium carbonate and silica react at this temperature to form calcium silicate, CaSiOs The liquid melt of CaSiOs dissolves iron(II) oxide forming a molten slag of mixed silicate ... 

CASH CBM CBO CBPC CC CCB CCM CCP CDB CEC CFBC CFC CFR CMM COP CSH CT Calcium aluminosilicate hydrate Coal bed methane Carbon burn-out Chemically-bonded phosphate ceramics Carbonate carbon Coal combustion byproducts Constant capacitance model Coal combustion product Citrate-dithionate-bicarbonate Cation exchange capacity Circulating fluidized bed combustion Chlorofluorocarbon Cumulative fraction Coal mine methane Coefficient of performance Calcium silicate hydrate Collision theory... 

Calcium—Silicon. Calcium—silicon and calcium—barium—silicon are made in the submerged-arc electric furnace by carbon reduction of lime, silica rock, and barites. Commercial calcium—silicon contains 28—32% calcium, 60—65% silicon, and 3% iron (max). Barium-bearing alloys contains 16—20% calcium, 9—12% barium, and 53—59% silicon. Calcium can also be added as an alloy containing 10—13% calcium, 14—18% barium, 19—21% aluminum, and 38—40% silicon These alloys are used to deoxidize and degasify steel. They produce complex calcium silicate inclusions that are minimally harmfiil to physical properties and prevent the formation of alumina-type inclusions, a principal source of fatigue failure in highly stressed alloy steels. As a sulfide former, they promote random distribution of sulfides, thereby minimizing chain-type inclusions. In cast iron, they are used as an inoculant. 

According to a recent patent [4], some unstable nitroso compounds may be stabilized by addition of such inert materials as ammonium bicarbonate, ammonium carbonate, magnesium acid phosphate, ammonium or sodium acid phosphate, calcium lactate, ammonium alum, and calcium silicate. 

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