Combustion, calcium carbonate effects

In a review of the course and mechanism of the catalytic decomposition of ammonium perchlorate, the considerable effects of metal oxides in reducing the explosion temperature of the salt are described [1], Solymosi s previous work had shown reductions from 440° to about 270° by dichromium trioxide, to 260° by 10 mol% of cadmium oxide and to 200°C by 0.2% of zinc oxide. The effect of various concentrations of copper chromite , copper oxide, iron oxide and potassium permanganate on the catalysed combustion of the propellant salt was studied [2], Similar studies on the effects of compounds of 11 metals and potassium dichromate in particular, have been reported [3], Presence of calcium carbonate or calcium oxide has a stabilising effect on the salt, either alone or in admixture with polystyrene [4],... 

In most developed countries, coal combustion and smelting facilities are required to treat gaseous and particulate arsenic in flue gases before the gases are released into the atmosphere (Chapters 5 and 7). Potentially effective sorbents for flue gas arsenic include hydrated lime (Ca(OH)2, portlandite), lime (CaO), calcium carbonate, limestone, fly ash, and sometimes activated carbon ((Jadhav and Fan, 2001 Lopez-Anton et al., 2007 Helsen and Van den Bulck, 2004), 287, 289 (Taerakul et al., 2006 Gupta et al., 2007) Chapters 5 and 7). The injection of hydrated lime is especially effective and probably... 

By way of an early example, the effect of calcium carbonate, ATH, and MH fillers on smoke production from styrene butadiene (SBR) foams has been reported.47 It was evident that all the fillers reduced soot formation relative to unfilled foam with the hydrated fillers being more effective than the calcium carbonate, which was considered to act merely as matrix diluent. ATH and MH were found to give enhanced char formation with the promotion of solid-state cross-linking as opposed to pyrolytic degradation. An afterglow effect, occurring after the extinction of the flame, was noted with MH and attributed to the slow combustion of carbon residues. 

Calcium carbonate and lithium carbonate fillers also act as HC1 absorbers and the effect on HC1 generation during the combustion of PVC-P has been shown to be effective, particularly when used in combination (15). 

A plasticised PVC was compounded with several fillers (lithium carbonate and various calcium carbonates), which acted as HC1 absorbers, and the effects of these fillers on the generation of HC1 during the combustion of PVC investigated. The synergistic effect of the fillers on HC1 uptake was also investigated as was the influence of the fillers on the mechanical properties and oxygen index of the plasticised PVC. The fillers were found to be effective as HC1 absorbers, particularly when used in combination. 9 refs. 

These materials have different effects on the way in which the composite burns. Precipitated calcium carbonates reduce acid gas emissions by reaction and neutralisation during combustion. This may in turn increase the ease of combustion, as the halogen has a gas-phase quenching effect. 

This is an idealized representation of a detergent. Calcium carbonate is suspended in oil with a sulfonate or phenate. The excess calcium carbonate provides a base reserve to oils and neutralizes acids that are formed during combustion. Detergents are also effective at keeping surfaces in the engine clean. The metals used to make detergents are typically calcium, magnesium, and sodium. Calcium is the most common. 

Occurrence. Carbon monoxide is a product of incomplete combustion and is not likely to result where a flame bums in an abundant air supply, yet may result when a flame touches a cooler surface than the ignition temperature of the gas. Gas or coal heaters in the home and gas space heaters in industry have been frequent sources of carbon monoxide poisoning when not provided with effective vents. Gas heaters, though properly adjusted when installed, may become hazardous sources of carbon monoxide if maintained improperly. Automobile exhaust gas is perhaps the most familiar source of carbon monoxide exposure. The manufacture and use of synthesis gas, calcium carbide manufacture, distillation of coal or wood, combustion operations, heat treatment of metals, fire fighting, mining, and cigarette smoking represent additional sources of carbon monoxide exposure (105—107). 

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