Chalk ground

Ereids-bad, n. chalk bath, -boden, m. chalky soil, -fiotte, /. chalk liquor, -grund, m. chalk ground, -gur,/. agaric mineral (earthy calcium carbonate). 

Calcium carbonate of natural origin chalk, ground limestone, phosphate chalk... 

Demtis F, Andrews JN, Parker A, Poole J, Wolf M (1997) Isotopic and noble gas study of Chalk ground water in the London Basin, England. Appl Geochem 12 763-773 Doney SC, Glover DM, Jenkins WJ (1992) A model function of the global bomb tritium distribution in precipitation, 1960-1986. J Geophys Res 97 5481-5492 Dunkle SA, Plummer LN, Busenberg E, Phillips PJ, Denver JM, Hamilton PA, Michel RL, Coplen TB... 

Calcium carbonate in its most common form is limestone and occurs naturally throughout the world as fossiliferous deposits composed of shells, teeth and bones from prehistoric organisms. Calcium carbonates used in the papermaking process fall into three groups chalk, ground (GCC), or precipitated (PCC). 

Calcium carbonate, natural n. CaCOsCaMg (C03)2. Pigment white 18 (77220). White extender pigment derived from natural chalk, limestone, or dolomite, consisting of calcium carbonate with up to about 44% magnesium carbonate. Density, 2.71 g/cm (22.6 lb/gal) O.A., 6-15 particle size, 1.5-12 pm. Syn calcite, limestone, whiting, marble flour, Paris white, chalk, ground oyster shells, Iceland spar, and Spanish white. 

The observed lag in responding to ortho-phosphate dosing is particularly important. It is likely explained by the longer time taken for the corrosion deposits within the lead pipes to reach equilibrium with the applied ortho-phosphate dose, due to organic and iron contents. In contrast, the observed lag in responding to ortho-phosphate was between 6 to 12 months in chalk ground-water fed supply systems in Eastern England. 

Low 0.06 90 Some high quality chalk ground-waters... 

A chromatographic column filled in three sections with ground sugar, chalk, and alumina. When a petroleum extract of spinach leaves is run onto the top of the column, ihe extract spreads down the column, but not uniformly bands of green chlorophylls stop near the top. yellow xanthophyll further down, and red carotene near the bottom. 

Materials suitable as filter aids include diatomaceous earth, expanded perilitic rock, asbestos, ceUulose, nonactivated carbon, ashes, ground chalk, or mixtures of those materials. The amount of body feed is subject to optimisa tion, and the criterion for the optimisa tion depends on the purpose of the filtration. Maximum yield of filtrate per unit mass of filter aid is probably most common but longest cycle, fastest flow, or maximum utilisation of cake space are other criteria that requite a different rate of body feed addition. The tests to be carried out for such optimisation normally use laboratory or pilot-scale filters, and must include variation of the filtration parameters such as pressure or cake thickness in the optimisation. 

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 carbonate, available both from natural sources and as precipitated forms (see Calcium compounds), is most useful in coating because of purity and high brightness, ie, 90—95%. Ground carbonates from marble deposits have high purity levels as do the carbonates from some chalk deposits. 

Calcium carbonate [471-34-17, CaCO, mol wt 100.09, occurs naturally as the principal constituent of limestone, marble, and chalk. Powdered calcium carbonate is produced by two methods on the industrial scale. It is quarried and ground from naturally occurring deposits and in some cases beneficiated. 

Hard Very Moderately Slightly Moderately borehole soft soft hard hard water lake surface river river (chalk water water water water formation) hard borehole water containing sodium bicarb- onate Very hard under- ground water... 

As the water runs over and through the ground, the carbonic acid reacts with the calcium carbonate of limestone or chalk and forms the more soluble hydrogen carbonate ... 

A two-component plugging material [1763] consists of an aqueous suspension of bentonite clay powder (20% to 25%), ground chalk (7% to 8%), sulfanol (0.10% to 0.15%), and carboxymethylcellulose (1.0% to 1.5%) as the first component. This solution is pumped into the formation. A gel is formed if diluted hydrochloric acid is pumped down and mixes with the first component. The hydrochloric acid is inhibited with a mixture of alkyl-polybenzyl pyridinium chloride and urotropin. 

CaC03, a white solid which occurs in nature as chalk, limestone and marble the ground product, often termed whiting, is used as an extending filler in rubber compounding. 

People whose houses are built on chalky ground find that their kettles and boilers become lined with a hard scale . We say that the water in the area is hard , meaning that minute amounts of chalk are dissolved in it. The hard layer of scale is chalk that precipitated onto the inside surface of the kettle or boiler during heating. 

Taber, Alberta Los Angeles Man, Baldwin Hills 26000 OxA-773 Chalk River 3390 90 3550 500 3560 [22 000-60 000 on geological grounds]... 

Materials handled include food products, chalk, coal, organic chemicals, clays, spent coffee grounds, sewage sludge and chicken manure. Where exhaust gases have unpleasant odours, after-burners can be supplied to raise the temperature and bum off the organic and particulate content causing the problem. 

Calcium carbonate is available as ground natural limestone and as synthetic chalk. It is widely used in paints, plastics, and elastomers. The volume relationship of calcium carbonate to resin or the pigment volume required to fill voids in the resin composite is called the pigment-volume concentration (PIVC). 

Ground calcium carbonate, extracted from the earth, is present in practically every country in the world in varying quantities in the form of limestone, marble, dolomite or chalk. Following the extraction, GCC needs to be ground. Dry grinding, the cheaper alternative, is often limited to a minimum particle size of 2- 3 microns. Wet grinding, more expensive, is used for fine and ultra fine material or when the final product must be a slurry (paper or paint application). Precipitated calcium carbonate is produced by chemical reaction between... 

NC 2.5, peanut meal (deproteinized deoiled, ground) 13, Na nitrate 26.4, chalk 0.3 diammoniurnphosphate 0.3%... 

---