Barium, deposition

These rosin-based sizes, whether paste, Hquid, or emulsions, can be used to size all grades of paper that are produced at acid pH. The latter include bleached or unbleached kraft Hnerboard and bag paper, bleached printing and writing grades, and cylinder board. In addition, polyaluminum compounds have been used in place of alum, most notably, polyaluminum chloride (48), which can reduce barium deposits where these have been a problem. The barium chloride by-product is more water-soluble than barium sulfate. Other polyaluminum compounds such as polyhydroxylated forms of alum and polyaluminum siHcosulfate have been evaluated as alum replacements. 

Sedimentary formation waters have long been invoked as ore-forming fluids in a number of distinctly different geologic settings. Although ore deposit classification schemes vary, the following have been genetically associated with basinal fluids (i) Mississippi-Valley-type lead, zinc, copper, barium, and fluoride deposits (ii) shale-hosted lead, zinc, and barium deposits (iii) rift-basin and redbed copper deposits ... 

A 60-year-old man with carcinoma of the hypopharynx aspirated barium into both lower lobes. He became hypoxic (Pa02 64 mmHg) and barium was extracted at bronchoscopy. He was given prophylactic antibiotics (cefotiam 2000 mg and metronidazole 500 mg intravenously every 8 hours for 4 days). A chest X-ray 6 days later showed residual barium deposition in the lower lobes. No further respiratory comphcations occurred. 

Precipitation in membrane near cathode side in presence of barium, deposits on anode... 

Sea water is desuUated to prevent any risk of sulfate barium deposit, and is injected from the start. Produeed water is to be reinjeeted after water breakthrougL Table 1 provides the eharacteristics of the desulfated sea water and formation water compositions. 

Bonatti, E., Fisher, D. E., Joensuu, O., Rydell, H. S., and Beyth, M. (1972). Iron-Manganese-Barium Deposit from the Northern Afar Rift, Ethiopia. Econ. Geol. 67, 717-730. 

The reaction mechanism for these products is not clearly understood, but the introduction of organo-metallic compounds (barium or iron salts in colloidal suspension) has been shown to have a beneficiai action on the combustion of diesel fuel in engines and reduce smoke. However, these products cause deposits to form because they are used in relatively large proportions (on the order 0.6 to 0.8 weight %) to be effective. 

From acid chlorides by selective hydrogenation in the presence of a catalyst (palladium deposited upon a carrier, which is usually barium sulphate but is... 

Strontianite is the naturally occurring form of strontium carbonate. It has a theoretical strontium oxide content of 70.2%, but no economically workable deposits are known. There are some naturally occurring strontium—barium and strontium—calcium isomorphs, but none has economic importance. 

Sulfamic acid and its salts retard the precipitation of barium sulfate and prevent precipitation of silver and mercury salts by alkah. It has been suggested that salts of the type AgNHSO K [15293-60 ] form with elemental metals or salts of mercury, gold, and silver (19). Upon heating such solutions, the metal deposits slowly ia mirror form on the wall of a glass container. Studies of chemical and electrochemical behavior of various metals ia sulfamic acid solutions are described ia Reference 20. 

Barium titanate thin films can be deposited on various substances by treating with an aqueous solution containing barium salts and an alkanolamine-modifted titanate such as TYZOR TE (151). In a similar fashion, reaction of a tetraalkyl titanate with an alkah metal hydroxide, such as potassium hydroxide, gives oxyalkoxide derivatives (KTi O(OR) ), which can be further processed to give alkali metal titanate powders, films, and fibers (152—155). The fibers can be used as adsorbents for radioactive metals such as cesium, strontium, and uranium (156). 

Barite [13462-86-7], natural barium sulfate, BaSO, commonly known as barytes, and sometimes as heavy spar, tiU, or cawk, occurs in many geological environments in sedimentary, igneous, and metamorphic rocks. Commercial deposits are of three types vein and cavity filling deposits residual deposits and bedded deposits. Most commercial sources are replacement deposits in limestone, dolomitic sandstone, and shales, or residual deposits caused by differential weathering that result in lumps of barite enclosed in clay. Barite is widely distributed and has minable deposits in many countries. 

Toxicity. The toxicity of barium compounds depends on solubility (47—49). The free ion is readily absorbed from the lung and gastrointestinal tract. The mammalian intestinal mucosa is highly permeable to Ba " ions and is involved in the rapid flow of soluble barium salts into the blood. Barium is also deposited in the muscles where it remains for the first 30 h and then is slowly removed from the site (50). Very Httle is retained by the fiver, kidneys, or spleen and practically none by the brain, heart, and hair. 

Electrical and Electronic Applications. Silver neodecanoate [62804-19-7] has been used in the preparation of a capacitor-end termination composition (110), lead and stannous neodecanoate have been used in circuit-board fabrication (111), and stannous neodecanoate has been used to form patterned semiconductive tin oxide films (112). The silver salt has also been used in the preparation of ceramic superconductors (113). Neodecanoate salts of barium, copper, yttrium, and europium have been used to prepare superconducting films and patterned thin-fHm superconductors. To prepare these materials, the metal salts are deposited on a substrate, then decomposed by heat to give the thin film (114—116) or by a focused beam (electron, ion, or laser) to give the patterned thin film (117,118). The resulting films exhibit superconductivity above Hquid nitrogen temperatures. 

Barium 2 2 Increase in blood pressure Discharge of drilling wastes discharge from metal refineries erosion of natural deposits... 

Two grams of the oU are saponified the portion insoluble in water separated by shaking with ether, and the aqueous solution neutralised with acetic acid. The solution is dUuted to 50 c.c. and 10 c.c. of cold saturated solution of barium chloride added. It is then warmed for two hours on a water-bath and allowed to cool. If a crystalline deposit is formed, the oil is to be considered adulterated, as the acids contained in normal lavender oil, acetic and butyric acids, give soluble barium salts. It is evident that this test will only detect those acids whose barium salts are insoluble. A more comprehensive test is therefore needed, as several other esters have since been employed for adulteration purposes. Glycerin acetate, prepared by the acetylation of glycerine, was first de-... 

Barium and strontium salts of polystyrene with two active end-groups per chain were prepared by Francois et al.82). Direct electron transfer from tiny metal particles deposited on a filter through which a THF solution of the monomer was percolated yields the required polymers 82). The A.max of the resulting solution depends on the DPn of the formed oligomers, being identical with that of the salt of polymers with one active end-group per chain for DPn > 10, but is red-shifted at lower DPn. Moreover, for low DPn, (<5), the absorption peak splits due to chromophor-chromophor interaction caused by the vicinity of the reactive benzyl type anions. 

The acetylacetonates are stable in air and readily soluble in organic solvents. From this standpoint, they have the advantage over the alkyls and other alkoxides, which, with the exception of the iron alkoxides, are not as easily soluble. They can be readily synthesized in the laboratory. Many are used extensively as catalysts and are readily available. They are also used in CVD in the deposition of metals such as iridium, scandium and rhenium and of compounds, such as the yttrium-barium-copper oxide complexes, used as superconductors. 1 1 PI Commercially available acetyl-acetonates are shown in Table 4.2. 

The deposition of thin films of the high-temperature superconductor yttrium-barium-copper oxide, YBa2Cu307, is obtained from the mixed halides, typically YCI3, Bal2, and CUCI2, with O2 and H2O as oxygen sources. Deposition temperatures are 870-910°C.f ]... 

YBa2Cu307 films are also obtained by MOCVD from a mixture of acetyl acetonates (tetramethyl heptadionate) of yttrium, barium, and copper, typically at a pressure of 5 Torr and at a deposition temperature of These precursor materials... 

Electrochemical processes in melts are often attended by side reactions and phenomena complicating the primary process. This is true, in particular, for the technically very important class of reactions in which a number of metals (calcium, barium, and others) are obtained electrometallurgically from molten salts. In many of these processes the metal that is deposited (sometimes in a highly disperse state) is found to interact with the corrosive melt for example, in a reaction such as... 

Two possible explanations for the difference in the chemical compositions of the Besshi-type ores and zinc-rich and barium-rich EPR-type ridge ores are (1) the different site of ore deposition, and (2) the different chemical nature of ore fluids. 

The scale may consist of calcium carbonate, barium sulfate, gypsum, strontium sulfate, iron carbonate, iron oxides, iron sulfides, and magnesium salts [943]. There are monographs (e.g.. Corrosion and Scale Handbook [159]) and reviews [414] on scale depositions available in the literature. 

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