Calcination first stage

The carbon dioxide given off during the calcination forms part of that used in the first stage of the operation. The mother liquid remaining after the separation... 

Experimental findings show that calcination reaction starts at every interior point of the reactant and after a certain time the reactant solid near the external surface is completely exhausted forming a bidisperse inert product layer. The period of reaction prior to the formation of the ash layer is designated as the first stage and the period following the formation of the ash layer as the second stage. 

Figure 7 shows a schematic diagram of the model calciner used for studying an economic continuous two-stage calcining system. The exhaust gas from first stage kiln is fed as fuel for second stage kiln. 

Table VI summarizes a typical heat balance in second stage of the above calcining system (Case A) in comparison with that of an alternative system (Case B) in which the exhaust gas from first stage kiln is not utilized for second stage calcination. The amount, composition and temperature of the exhaust gas from first stage kiln determine the auxiliary fuel requirements for second stage kiln.

Accordingly the key first stage of manufacturing a monolithic type catalyst is formulation of the wash coat and uniform application over the internal surface of the monolith. Although commercial processes are proprietary with little detail available, the coating is generally fixed, by calcination, at elevated temperature. 

Frontier between Polynuclear Aromatic Compounds and Graphite. The calcined petroleum coke shows chemistry that contains components of both graphite and polynuclear aromatic hydrocarbons. Like graphite, the calcined petroleum coke forms first-stage intercalation compounds with both potassium and cesium metals. These compounds are iden-... 

In the commercial production of plaster of Paris by the Kettle Process, the gypsum is first ground and then transferred to shallow pans, known as kettles, each holding some 12 tonnes of gypsum. During calcination, the loss of water may go beyond the first stage shown in the equation above, resulting in the loss of a further 1 Yi molecules -... 

It has been demonstrated that sequential precipitation in a moderately acid pH range for the binary metal systems Cu/Al, Cu/Cr, Cu/Fe and Nl/Fe in the presence of oxalic acid with aluminum or ferric hydroxide as the first stage and adsorption/precipitation of copper or nickel as the second stage provides metal oxides (after 250-350° C air calcine) with considerable enhancement in dispersion and in catalytic activity, notable for Cu/Al, for the room temperature decomposition of hydrogen peroxide and benzaldehyde oxidation by hydrogen peroxide. 

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