Calcium carbonate specific heat

Fillers. These are used to reduce cost in flexible PVC compounds. It is also possible to improve specific properties such as insulation resistance, yellowing in sunlight, scuff resistance, and heat deformation with the use of fillers (qv). Typical filler types used in PVC are calcium carbonate, clays, siHca, titanium dioxide, and carbon black. 

Most chemical treatment programs have not in the past specifically focused on controlling silica levels in cooling water, and as a consequence almost all analyses of scales and deposits taken from the waterside of cooling systems, especially from heat exchangers, have shown the presence of small percentages of silica. Research over the last five years or so has led to the introduction of silica-specific deposit control polymers and has also led, with some success, to the reevaluation and promotion of some established calcium carbonate polymer products for effective silica control. 

With a specific heat of about 0.90 J/g°C at 100°C (0.214 cal/g°C varies with temperature) calcium carbonate requires some 7.92 x lO kJ/tonne of sensible heat simply to bring it up to the final kiln temperature. 

In some solar-heated homes, heat from the sun is stored in rocks during the day and then released during the cooler night, (a) Calculate the amount of heat required to raise the temperature of 78.7 kg of rocks from 25.0°C to 43.0°C. Assume that the rocks are limestone, which is essentially pure calcium carbonate. The specific heat of calcium carbonate is 0.818 J/g-°C. (b) Suppose that when the rocks in part (a) cool to 30.0°C, all the heat released goes to warm the 10,000 ft (2.83 X 10 L) of air in the house, originally at 10.0°C. To what final temperamre would the air be heated The specific heat of air is 1.004 J/g-°C, and its density is 1.20 X 10 g/mL. 

A recipe used with, escellent results is looo c.c. wort of specific gravity i Oo8, i per cent, of gelatin, i per cent, calcium carbonate, and 2 per cent, ar. Heat gently, filter, sterilize, and make up into tubes. Attempts to prepare plate cultures with this medium have been unsuccessfulv... 

Most every chemical reaction is accompanied by the absorption or evolution of heat. Those reactions that absorb heat as they take place are called endothermic reactions. If the source of heat is removed from an endothermic reaction, it stops. Many decomposition reactions are endothermic processes, and for each individual decomposition reaction the amount of heat needed to decompose 1 mole of that specific compound is always the same. For example, it requires 178 kj (kilojoules) of heat energy to decompose 1 mole of CaC03 to CaO and C02. The heat quantity is added to the reactant side of the equation to indicate it is absorbed (consumed) as 1 mole of calcium carbonate decomposes. 

However, at lower temperatures, the retention of sulfur dioxide by the calcium carbonate is favored. For temperatures lower than 760°C (1400°F), several difficulties arise (1) the coal does not burn rapidly, (2) the scavenging or retention of sulfur dioxide does not proceed very rapidly, and (3) heat transfer to the boiler tubes is markedly decreased. Therefore, the operating temperature of a fluidized-bed boiler must be selected with care and may vary according to the specific coal used. 

The most important raw materials are metal ores, for example metal oxides, sulfides, carbonates and halides. Some specific examples are bauxite (aluminium oxide), pyrite (iron (II) sulfide), limestone (calcium carbonate) and salt (sodium chloride). Metals are extracted from their ores, for example aluminium from bauxite, and can then be converted into their salts. In some cases processing does not yield the metal but another compound — limestone on heating above 1 170 °C is converted to quicklime (CaO). This reacts with water to give slaked lime (Ca(OH)2). A number of non-metals are also extracted from minerals. One example is phosphorus, which is produced by the reduction of phosphates with coke and sand in an electric furnace. 

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