Refined Borates

In 1986, Turkey produced nearly one million metric tons of mineral concentrate, whereas production of refined borate chemicals was 89,500 metric tons. Annual production capacities of chemicals at Eskiseher were pentahydrate borax, 160,000 t anhydrous borax, 60,000 t and decahydrate borax, 17,000 t. Capacities at Bandermes were decahydrate borax, 55,000 t boric acid, 33,000 t and sodium perborate, 64,000 t (103). 

The most versatile of all borates as a synthetic reagent, orthoboric acid, B(0H)3, is the second most important refined borate product in terms of industrial tonnage. It is typically manufactured by reacting a borate ore, particularly kernite or colemanite, with sulfuric acid, Eqs. (8) and (9). 

Kernite (Na2[B40s(0H)2] 3 H2O = Na20 2 B2O3 4 H2O) is also an important industrial mineral that is mainly used to produce refined borates, boric acid and borax. The polymeric borate structure of the kernite is shown in Fig. 7b above. Upon hydration, kernite converts to the monomeric borate tincal, which dissolves more readily. Thus, kernite may be hydrated to facilitate processing into borax. Although primarily a raw material for the manufacture of refined borates, concentrates of this mineral have been used as industrial products. 

RTM produces borax decahydrate, borax pentahydrate, anhydrous borax, boric acid (BA), boric oxide, and other specialty borates such as zinc borates from sodium borate minerals. Etibank, a Turkish national mining enterprise, offers borate minerals (colemanite and ulexite) as well as refined borates. 

Manufacture. The majority of boric acid is produced by the reaction of inorganic borates with sulfuric acid in an aqueous medium. Sodium borates are the principal raw material in the United States. European manufacturers have generally used partially refined calcium borates, mainly colemanite from Turkey. Turkey uses both colemanite and tincal to make boric acid. 

It is possible to determine components in complex EPs where matrix effects can be severe. For example, zinc (as zinc borate), chlorine (as dechlorane flame retardant), antimony (as oxide) and fibre-glass have been determined in nylon using just one standard. Many users have refined the universal precalibrated programmes for standardless XRF and made them more efficient for matrix correction by using variable correction coefficients. OilQuant offers possibilities for analysing polymers [243]. Software packages usually provide ... 

Borax decahydrate occurs in nature as mineral, borax (tincal). It is one of the most common sodium borate ores. The compound has several industrial applications. The refined material is mostly used in household cleaning products. It is used to make pyrex and other horosilicate glasses. Borax is added to fertilizers in small quantities as a source of boron, as a trace nutrient for plants. High purity grade borax is used in cosmetics, toilet products and electrolytic capacitors. It also is used in fire retardants, adhesives and herbicides. 

Their principal parent compound is Hydrofluoric (or Phthoric) Acid Gas. (Hydrogen Fluoride), HF, mw 20.01 colorless, very poisonous gas, density 0.713(Air l,0), sp gr of liquid 0.988 at +13.6°, fr p -83°, bp +19-4° sol in w or ale. Can be prepd by distilling from a mixture of Ca fluoride (fluorspar) and sulfuric acid. Used as an additive in liquid rocket proplnts and in refining of uranium. Also as fluorinating agent in org and inorg reaction prepn of A1 fluoride, other fluorides, fluoro-borates, fluomcarbonaces, fluorocarbons and fluorosili cates... 

The titration data were analyzed by a computer program, which was a modification of the program SCOGS (17). The systems Ni(II) and L-serine or L-threonine, as analogs of amino-sugar acids, and boric acid and mannitol-borate were evaluated. For each of these systems it was convenient to refine first the formation constants for the simple complexes, such as ML and ML2, adding other more complex species later until the best fit to the data had been obtained. 

The first preparations of diaryliodonium salts have been reported in the 19th century, but refinements and improvements keep appearing to date. In most cases an iodoaryl species containing iodine(III) is coupled with an arene or a derivative of it in a typical electrophilic aromatic substitution. Lithiated, stannylated or silylated aryls and arylboronic acids or borates have been introduced recently in order to avoid harsh conditions and to improve yields. The iodoaryl species may be also formed in situ from arenes and iodine(III) reagents. 

Crude and refined hydrated sodium borates and hydrous boric acid are produced from kernite and tincal. The ore is fed to the dissolving plant and mixed with hot recycle liquor. Liquor and fine insolubles are fed to a primary thickener. The strong liquors are crystallized in a continuous vacuum crystallizer. 

Magnesium electrochemistry in molten salts media is especially important for the mass production of the pure metal. Magnesium is frequently produced and refined by electrolysis of high-temperature, molten eutectic mixtures of anhydrous MgCl2 with various salts, such as KC1, CaCl2 etc. High-temperature molten salts baths, with similar compositions, with the addition of borate are also studied for the production of MgB2. 

While early work emphasized high symmetry of this ligand, the current trends may take advantage of asymmetric substitution to adapt the basic poly(l-pyrazolyl)borate framework to various enzyme-like tasks. This could be done by placing appropriate functionalities in such a manner that they will interact, as needed, with a transition metal (or metals). Achievement of these refinements of the ligand stem is likely to result from advances in boron chemistry, boron being here the pivotal element,... 

Both carbides are prepared as crystals from fused-sait electrolysis of carbonate-borate-fluoride-metal oxide salt baths. Large crystals of MojC are grown in a process d where the powdered carbide is added to a molten region on a growing solid rod. Zone refining also gives single crystals. 

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