Calcium carbonate ignition

Fillers (qv) are occasionally used in flexible slab foams the two most commonly used are calcium carbonate (whiting) and barium sulfate (barytes). Their use level may range up to 150 parts per 100 parts of polyol. Various other ingredients may also be used to modify a flexible foam formulation. Cross-linkers, chain extenders, ignition modifiers, auxiHary blowing agents, etc, are all used to some extent depending on the final product characteristics desired. 

The TEB value may be obtained by either the sum of the individually measured cations or by evaporating and igniting a portion of the ammonium ethanoate leachate to convert the metallic cations to oxides and carbonates, followed by addition of excess acid (to convert carbonates to chlorides) and back-titration with alkali. The latter method is difficult if the soil is insufficiently base-rich to provide an adequate amount of bases for the titration. On the other hand, the calcium carbonate in calcareous soils may be partially leached by the ammonium ethanoate at pH 7.0 in addition to the exchangeable bases and thus give an exaggerated TEB value and a percentage base saturation in excess of 100%. The TEB by ignition/titration can serve as a check on the values from the summation method. 

Crude calcium sulfide may be obtained by ignition of pulverized calcium sulfate with charcoal. The products also may contain calcium carbonate, sulfite, carbonaceous ash and unreacted calcium sulfate. In the laboratory, pure calcium sulfide may be prepared by heating pure calcium carbonate with hydrogen sulfide and hydrogen at 1,000°C ... 

Luminous calcium sulfate is prepared by the ignition of calcium carbonate with sulfur in the presence of small quantities of manganese or bismuth salts. 

Sodium and potassium oxides cannot be conveniently made by calcining the corresponding carbonate and digesting the residue with water as is possible in the case of calcium oxide, because the two alkali carbonates do not decompose so readily on ignition as calcium carbonate. Lithium carbonate, however, is more closely related to calcium carbonate than the other alkali carbonates. The preparation of the oxides of potassium and sodium is rather difficult and expensive. 

RUB A LUMP OF SUGAR WITH CIGARETTE ASHES (TO ACT AS CATALYST). IGNITE. DIP TEST TUBE IN LIME WATER. HOLD OVER BURNING SUGAR. FILM OF CALCIUM CARBONATE SHOWS CO, IN FLAME—PROVING THAT THERE IS CARBON IN SUGAR. 

Shut off all possible sources of ignition. Wear nitrile rubber gloves, laboratory coat, and eye protection. A self-contained breathing apparatus may be necessary, depending on the size of the spill. Cover the spill with a 1 1 1 mixture by weight of sodium carbonate or calcium carbonate, clay cat litter (bentonite), and sand. When the acetic anhydride has been absorbed, scoop into a plastic pail and, in the fume hood, very slowly add the mixture to a pail of cold water. Allow it to stand for 24 hours. Test pH of the solution and neutralize if necessary with sodium carbonate. Decant the solution to the drain with water. Treat the solid residue as normal refuse. The spillage site should be washed thoroughly with soap and water.19-22... 

Shut off all possible sources of ignition. Wear nitrile rubber gloves, laboratory coat, and eye protection. A self-contained breathing apparatus may be necessary, depending on the size of the spill. Cover the spill with a 1 1 1 mixture by weight of sodium carbonate or calcium carbonate, clay cat litter (bentonite), and sand. When the acetyl chloride has been... 

Properties On ignition, reaction between zinc dust and hexachlorethane produces zinc chloride and free carbon, both of which pass off in the smoke. The ammonium perchlorate keeps the reaction going, ammonium chloride readily volatilizes and controls the rate of burning, and calcium carbonate stabilizes the mixture by taking up any hydrochloric acid which may be present. The smoke is harmless. 

The conventional approach to asphalt analysis has been to extract the bitumen with an organic solvent and then to characterize bitumen and minerals separately. Sulfur content and melting point are commonly measured properties of bitumen. Minerals are generally screened and then subjected to simple quantitative tests. Measurement of weight loss on ignition helps to distinguish between calcium carbonate, which loses... 

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