Lump quicklime

Lump graphite, 12 784-785, 793 Lump quicklime, 15 28 Luna Innovations, 1 718 Lung cancer, asbestos and, 3 316 Lungs... 

Lump quicklime usually refers to products with a top size above 2.5 cm. 

Fluxing lime is lump or pebble quicklime used as flux in steel (qv) manufacture the term may also be appHed more broadly to include fluxing of nonferrous metals and glass (qv). It is a type of chemical lime. 

Texture. All limestones are crystalline, but there is tremendous variance in the size, uniformity, and arrangement of their crystal lattices. The crystals of the minerals calcite, magnesite, and dolomite are rhombohedral those of aragonite are orthorhombic. The crystals of chalk and of most quick and hydrated limes are so minute that these products appear amorphous, but high powered microscopy proves them to be cryptocrystalline. Hydrated lime is invariably a white, fluffy powder of micrometer and submicrometer particle size. Commercial quicklime is used in lump, pebble, ground, and pulverized forms. 

Calcium Oxide (lime, Quicklime, Burnt Lime, Calx, Unslaked Lime, Fluxing Lime). CaO, mw 56.08, white or greyish-white lumps or powd, mp 2580°, bp 2850°, d 3.25-3.40g/cc. SI sol in w with formation of calcium hydroxide and evolution of large amts of heat sol in acids, and insol in ethanol. Coml prepn consists of heating calcium carbonate in kilns at 1000—1100° until all of the C02 is driven off. Lab prepn is by burning calcium carbonate or calcium oxalate at about 800° using a quartz crucible in an electric furnace... 

PLACE A LUMP OF LIME (QUICKLIME, CALCIUM OXIDE) IN A CUSTARD CUP. ADD AS MUCH LUKEWARM WATER AS IT WILL ABSORB. LIME HEATS UP, GIVES OFF STEAM, CRUMBLES INTO POWDER OF SLAKED LIME (CALCIUM HYDROXIDE). 

WHEN WATER IS ADDED TO LUMPS OF QUICKLIME (CoO), THEY CRUMBLE INTO A WHITISH POWDER OF SLAKED OK HYDRATED LIME (Co(OH)a). (SEE ALSO PAGE 45.)... 

To prepare absolute alcohol, 100 gms. of freshly burnt quicklime in the form of small lumps are placed in a 500-c.c. distilling flask, and 300 gms. of rectified spirits added. After 8 hours the alcohol is distilled off on a water bath until a thermometer in the neck of the flask indicates 80°. The alcohol so obtained still contains about 3% of water. 

Method I.—The apparatus described in Preparation 1 is fitted up, a 500-c.c. flask being used, and 30 gms. (1 mol.) of finely powdered tartaric acid, 150 gms. (excess) of absolute alcohol, and 50 gms. of crystallised benzene placed in the flask. The object of the benzene is to help to volatilise the water produced by forming with it and the alcohol the low boiling ternary system—alcohol-benzene-water. The iron tube is packed with small lumps of good quicklime, and is heated to a temperature of 90°. The mixture in the flask is boiled, a few pieces of porous porcelain being added to promote steady ebullition. Esterification proceeds almost to completion, owing to the removal by the quicklime of the water formed. After 6 hours, the liquid in the flask, which will have become quite viscid owing to the formation of the ester, is distilled on a water bath until all the benzene and excess of alcohol have been removed the residue is fractionated from a metal bath under reduced pressure. 

Quicklime (in the form of lumps) is periodically loaded with slusher 1 into apparatuses 2 for slaking the apparatuses are filled with technical water through vapour-heated shell-and-tube heat exchanger 3. Slaking forms lime milk and solid residue (cinder). The cinder is sent out of apparatuses 2 with facilities for forced unloading into transporter 4 lime milk flows down a chute into screw trap 5 and reservoirs 6. Small pieces of cinder are sent from the trap with screws to the transporter. The cinder in the form of dirt is transported into bunker 7 and periodically removed. Lime milk in reservoirs 6 is constantly mixed so that the suspension does not settle. The weight ratio of Ca(OH)2 is determined by the density of the sample of lime milk from the reservoirs it should be 10 - 18%. 

Calcium Oxide and Water. The well-known substance quicklime is calcium oxide. Calcium oxide could be made by burning bits of calcium, but the oxide quickly coats over the surface of the metal, and it is difficult to make the interior portions of the lump react. For this experiment take a lump of quicklime out of a recently opened container. Cover it with water in a porcelain dish and then pour off the excess of water that did not soak into the porous lump. Note... 

Mean apparent density. As the heat treatment of individual lumps in a commercial lime kiln can vary widely, their apparent densities also vary. The mean apparent density is used to characterise the average degree of sintering of a particular quicklime. For a particular high-calcium quicklime, the mean apparent density correlates with the reactivity to water (see Fig. 13.2). 

Thus the properties of quicklime from a given kiln reflect the average properties of individual lumps, each of which has experienced a particular time-temperature history. Fig. 15.8 compares the distribution of particle densities for a light-burned quicklime from an annular shaft kiln, with a mean apparent density of 1.66 g/cm with that of a solid-burned quicklime from a coal-fired traditional shaft kiln with a mean apparent density of 2.15 g/cm. Table 15.4 presents some typical... 

Sheeted tipper waggons or covered rail hoppers are generally the most economical form of transport for lump and granular quicklimes which have been screened to remove the fines (e.g. < 5 mm particles). Air pressure discharge vehicles are used for fines and ground lime products and may also be used on product with a top size of up to 20 mm. Intermediate Bulk Containers are also used. 

Skip hoists can be used for all granular and lump grades but are more suitable for particles greater than 100 mm. Elevators — both belt-and-bucket and chain-and-bucket types — have been used for all grades of quicklime. The system should minimise spillage within the equipment and ensure that wear on linkages caused by the quicklime is minimised. 

High-calcium limes, which include lump and pulverised quicklime, hydrated lime and milk of lime, are categorised in [28.3] into three Types (Table 28.1), depending on the levels of the major and minor components, namely ... 

Ground" refers to pulverised high-calcium quicklime, lump" refers to granular high-calcium quicklime, hydrate" refers to hydrated high-calcium lime and milk" refers to milks of lime % values are by mass. 

Many sugarbeet processing plants operate lime kilns on-site to produce both the quicklime and the carbon dioxide required for the purification process. Shaft kilns are generally used, burning lump limestone. A few plants calcine the dried carbonation sludge, using rotary and circular multiple hearth kilns [30.6]. 

Calcium oxide, CaO, is generally produced in die form of crystals, white or greyish white lumps or a granular powder. Commercial material may have a yellowish or brownish tint, due to die presence of iron MerckIndex, 1996). It is also known as lime (. v.), burnt lime, calx and quicklime. 

Calcium oxide, CaO, quicklime Pebble, lump, ground, granules, crushed Bags 100 lb bulk Reacts with water to form hydrated lime, solubility 0.16 70-96... 

Lime was often used in combination with natural cement. The Ume used by the Corps of Engineers in the 19th century was almost invariably quicklime, packed in sealed barrels in a lump condition. This material would be slaked on site, as the economic penalty for shipping lime as a paste or putty with excess water would have been out of the question. The primary objective of slaking is described as lump reduction, allowing the Ume to be distributed uniformly in the mortar and to achieve a smoother, mote workable consistency. 

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