Of barium carbonate

Simple examples of WLN are C2H5OH is Q2 CH3C0 0CH3 is IVOl For branch chain and fused ring structures rules determine the order of notation. It is claimed that over 50% of all organic structures can be represented by less than 25 characters, witherite, BaCOj. The white mineral form of barium carbonate. Used as a source of Ba compounds and in the brick and ceramic industries. 

One commercial process for producing sodium sulfide is as a by-product of barium carbonate production (see Barium compounds). Barite ore, BaSO, is reduced with carbon at 800°C to produce cmde barium sulfide (black ash), which is then leached to dissolve the barium sulfide in solution. The solution is then reduced using sodium carbonate to produce barium carbonate, leaving a weak sodium sulfide solution as the by-product. The sodium sulfide solution may then be concentrated and flaked or crystallized. 

The main electroceramic apphcations of titanium dioxide derive from its high dielectric constant (see Table 6). Rutile itself can be used as a dielectric iu multilayer capacitors, but it is much more common to use Ti02 for the manufacture of alkaline-earth titanates, eg, by the cocalciuation of barium carbonate and anatase. The electrical properties of these dielectrics are extremely sensitive to the presence of small (<20 ppm) quantities of impurities, and high performance titanates require consistently pure (eg, >99.9%) Ti02- Typical products are made by the hydrolysis of high purity titanium tetrachloride. 

Alkaline-Earth Titanates. Some physical properties of representative alkaline-earth titanates ate Hsted in Table 15. The most important apphcations of these titanates are in the manufacture of electronic components (109). The most important member of the class is barium titanate, BaTi03, which owes its significance to its exceptionally high dielectric constant and its piezoelectric and ferroelectric properties. Further, because barium titanate easily forms solid solutions with strontium titanate, lead titanate, zirconium oxide, and tin oxide, the electrical properties can be modified within wide limits. Barium titanate may be made by, eg, cocalcination of barium carbonate and titanium dioxide at ca 1200°C. With the exception of Ba2Ti04, barium orthotitanate, titanates do not contain discrete TiO ions but ate mixed oxides. Ba2Ti04 has the P-K SO stmcture in which distorted tetrahedral TiO ions occur. 

Most barium compounds are prepared from reactions of barium carbonate [513-77-9] BaCO, which is commercially manufactured by the "black ash" process from barite and coke ki a process identical to that for strontium carbonate production. Depending on the co-product, soda ash and/or carbon dioxide are also consumed. 

A pliotornicrograpli of barium carbonate fomied by precipitation using pure soda asli (eq. 9), is shown in Figure 3. Tire av erage particle size is 1.2 ]lm. Tire exclusive use of soda ash results in a barium carbonate having included sodium that cannot be reduced below a certain level by repeated washings. Tire sodium can be detrimental if the BaCO is to be used for barium titanate production. 

Uses. Hiere are several different grades of barium carbonate manufactured to fit the specific needs of a wide variety of applications very fine, highly reactive grades are made for the chemical industry coarser and more readily haridleable grades are mainly supplied to the glass industry ... 

In the oil-weU drilling industry, the barite suspension used as drilling mud can be destabilized by the presence of soluble materials such as gypsum. Addition of barium carbonate precipitates the gypsum, inhibits coagulation, and thus permits the mud to retain the desired consistency and dispersion. 

Barium titanate is usually produced by the soHd-state reaction of barium carbonate and titanium dioxide. Dielectric and pie2oelectric properties of BaTiO can be affected by stoichiometry, micro stmcture, and additive ions that can enter into soHd solution. In the perovskite lattice, substitutions of Pb ", Sr ", Ca ", and Cd " can be made for part of the barium ions, maintaining the ferroelectric characteristics. Similarly, the TP" ion can partially be replaced with Sn +, Zr +, Ce +, and Th +. The possibihties for forming solution alloys in all these stmctures offer a range of compositions, which present a... 

The ester is hydrolysed by refluxing for l-2h with 1-5% of barium carbonate suspended in water or with aqueous sodium carbonate solution. The solution is cooled and extracted with diethyl ether, toluene or chloroform. It is then acidified and the acid is collected by filtration or extraction, and recrystallised or fractionally distilled. 

The alcoholic filtrate is evaporated to 50 cc., and 50 g. of barium hydroxide and 150 cc. of distilled water are added (Note 4). The mixture is refluxed for two hours and the excess barium hydroxide is precipitated with carbon dioxide. The barium carbonate is removed by filtration and washed with hot distilled water. A slight excess of sulfuric acid is added to the filtrate to liberate the amino acid from its barium salt, and an excess of barium carbonate is added to remove sulfate ion. The mixture is digested on the steam bath until effervescence ceases, and it is then filtered and the precipitate is washed with hot distilled water. The filtrate and washings are concentrated on the steam bath to a volume of 100 cc., decolorized with i g. of active carbon, filtered, and concentrated to the point of crystallization (about 25 cc.). The amino acid is precipitated by the addition of 150 cc. of absolute alcohol and the product is collected and washed with absolute alcohol. 

Kasuganobiosamine (4) and Kasugamycinic Acid (9a) by cold Alkaline Hydrolysis. Kasugamycin hydrochloride (622 mg., 1.43 mmoles) was dissolved in 5 ml. of water free from carbon dioxide and 50 ml. of water saturated with barium hydroxide was added. The solution was allowed to stand at room temperature for 36 hours. Ammonia (0.30 mmole) was produced and barium oxalate (199 mg., 0.80 mmole) was obtained. After removal of barium oxalate by filtering, the filtrate was neutralized with dry ice. After removal of barium carbonate by filtering, the filtrate was adjusted to pH 7.0 and placed on a column of Amberlite CG-50 (ammonium form, 1.5 x 22 cm.), allowed to pass with a rate of... 

Reactions of barium carbonate with various oxides... 

Figura 2.9 Dse of th Grob test Mixture to compare tbe activity of various glass surfaces coated with ov-ioi. Surface types A > Untreated pyrex glass, B pyrex glass deactivated by thermal degradation of Ceurbowax 20M, C < SCOT column, prepared with Silanox 101, D pyrex glass column coated with a layer of barium carbonate and deactivated as in (B), and E - untreated fused silica. Components are identified in Table 2.7 with ac - 2-ethylhexanoic acid. (Reproduced with permission from ref. 152. Copyright Elsevier Scientific Publishing Co.)...

Turanose Phenylosotriazole. A solution of 15 g. of turanose phenylosazone in 300 cc. of hot water was placed on the steam-bath and a solution of 22 g. of copper siilfate pentahydrate in 150 cc. of hot water was added. The mixture turned a deep cherry-red at once and in a short time (fifteen min.) a red precipitate had formed and the solution had become green. After thirty minutes from the time of addition of the copper solution, the solution was cooled, filtered, and the copper removed as sulfide. The clear light yellow filtrate was neutralized with 45 g. of barium carbonate and the insoluble material removed by filtration. The filtrate was extracted with five 50-cc. portions of ether to remove the aniline, and the aqueous portion was concentrated in vacuo to a thick sirup. The sirup was dissolved in 60 cc. of warm alcohol, filtered to remove a slight turbidity and diluted with 65 cc. of ether. Upon cooling and scratching, the product crystallized as large prisms yield 8.9 g. (72%). The phenylosotriazole was recrystallized from 10 parts of alcohol and when pure showed the melting point 193-194° and rotated [a Jj" + 74.5° in aqueous solution (c, 0.90). 

Since aldehydes are notoriously polymerizable and difficult to manipulate, the products of periodate oxidation are oftentimes further oxidized, with hypohalite, to carboxylic acids, or are reduced to the corresponding alcohols. Oxidation has been more usually employed than reduction, since acids frequently form crystalline salts and other conveniently prepared derivatives. A process of oxidation of these aldehydic products by hypo-bromite, in the presence of barium carbonate or strontium carbonate, was developed and used extensively by Hudson and his coworkers.107 110 194-199,90s Their method can best be illustrated by an example the further oxidation of the dialdehyde, VI, shown previously (see p. 16) to be obtained by the oxidation of the methyl a-D-aldohexopyranosides. The isolation of... 

By hydrolysis under very mild alkaline conditions (with a boiling suspension of barium carbonate), ribonucleic acids have been shown to yield small quantities of cyclic phosphates as well as the normal nucleotides.96 These materials were identical electrophoretically with synthetic cyclic phosphates and were readily hydrolyzed to mixtures of 2- and 3-phosphates. Their formation in this way constitutes strong support for Brown and Todd s theory. The precise way in which the alkaline hydrolysis of the polynucleotide occurs has been studied using isotopically labeled water, and the results are in agreement202 with the scheme outlined above. 

The compound Ba5[Ru2(0)n] has been synthesized by solid-state reactions of barium carbonate with ruthenium oxide. The X-ray structure shows that it contains peroxide ions and the ruthenium is in the +5 oxidation state, i.e., Ba5[Ru2(02)0g]. The novel mixed-valence Ru — Ru triple perovskites, Ba3M[Ru2(0)9] (M = Li, Na), have been grown from reactive hydroxide fluxes. ... 

Barium acetate is made by the reaction of barium carbonate with acetic acid ... 

Barium titanate is made by sintering a finely powdered mixture of barium carbonate and titanium dioxide in a furnace at 1,350°C. The calcined mass is finely ground and mixed with a binder (plastic). The mixture is subjected to extrusion, pressing or film casting to obtain ceramic bodies of desired shapes. Plastic is burnt off by heating and the shaped body is sintered by firing and then pobshed. 

One solution that has been devised makes use of barium carbonate to trap the NO The trap contains a finely divided platinum cata-... 

Another example of a selective dehalogenation in the carbohydrate field has been reported by Hanessian and Plessas.83(b) Catalytic hydrogenation of methyl 4-0-benzoyl-3-bromo-2,6-dichloro-2,3,6- tri-deoxy-a-D-mannopyranoside over palladium-on-carbon in the presence of barium carbonate gave methyl 4-0-benzoyl-6-chloro-2,3,6-... 

Lithium.—In order to extract lithium from the silicate minerals—petalite, lepidolite, spodumene, amblygonite, etc.—J. J. Berzelius 3 fused the finely powdered mineral with twice its weight of calcium or barium carbonate. L. Troost fused a mixture of finely powdered lepidolite with an equal weight of barium carbonate, half its weight of barium sulphate, and one-third its weight of potassium sulphate. In the latter case, two layers were formed lithium and potassium sulphates accumulated in the upper layer from which they were extracted by simple lixiviation. The sulphates are converted to chlorides by treatment with barium chloride. The filtered liquid is evaporated to dryness, and the chlorides extracted with a mixture of absolute alcohol, or pyridine. The lithium chloride dissolves, the other alkali chlorides remain as an almost insoluble residue. 

Precipitate with aq. ammonia. Evaporate the soln. down to about 100 c.c., and filter the ot liquid so as to remove calcium sulphate. The cone. soln. is sat. with ammonium alum and allowed to stand for some time. The mixed crystals of potassium, rubidium, and oeesium alums and of lithium salt are dissolved in 100 c.c. of distilled water and recrystal-lized. The recrystallization is repeated until the crystals show no spectroscopic reaction for potassium or lithium. The yield naturally depends on the variety of lepidolite employed. 100. grms of an average sample gives about 10 grms. of crude crystals and about 3 grms. of the purified caesium and rubidium alums. For the purification of caesium and rubidium salts, see the chlorides. The mother-liquors are treated with an excess of barium carbonate, boiled, and filtered. The filtrate is acidified with hydrochloric acid, and evaporated to dryness. The residue is extracted with absolute alcohol in which lithium chloride is soluble, and the other alkali chlorides are sparingly soluble. 

J. Townsend patented the use of a mixture of barium carbonate and calcium oxide for converting the sulphate to carbonate. D. Hill and G. Lunge found that the reaction is complete with precipitated barium carbonate, but not with native carbonate, provided an excess of the carbonate and lime be used, the cost also is prohibitive. M. Pongowsky patented the process of converting sodium sulphate into carbonate by adding powdered limestone to an alkaline soln. of the sulphate, and treating the mixture with carbon dioxide with constant agitation. Calcium bicarbonate is formed, and this converts the sodium sulphate into carbonate. 

By treating the crude solution of perdisulphuric acid with the requisite quantity of barium carbonate or hydroxide, the unaltered sulphuric acid can be removed and a pure aqueous solution of pcrdi-sulphuric acid obtained.4... 

Ceramic Method. Mixtures of barium carbonate and iron oxide are reacted at 1200-1350 °C to produce crystalline agglomerates which are ground to a particle size of ca. 1 pm. This method is only suitable for the high-coercivity pigments required for magnetic strips [5.35],... 

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