Boron world production

Diamond. Diamond [7782 0-3] is the hardest substance known (see Carbon, diamond, natural). It has a Knoop hardness of 78—80 kN/m (8000—8200 kgf/m ). The next hardest substance is cubic boron nitride with a Knoop value of 46 kN/m, and its inventor, Wentorf, beheves that no manufactured material will ever exceed diamond s hardness (17). In 1987 the world production of natural industrial diamonds (4) was about 110 t (1 g = 5 carats). It should be noted that whereas the United States was the leading consumer of industrial diamonds in 1987 (140 t) only 260 kg of natural industrial diamonds were consumed this is the lowest figure in 48 years (4), illustrating the impact that synthetic diamonds have made on the natural diamond abrasive market. 

Boron. Virtually all United States boron production and about three-fifths of the world production comes from bedded deposits and lake brines in California. U.S. reserves are adequate to support high production levels. Turkey is the only other boron-producing country of significance. Only about 5% of boron production is used in agriculture. 

To screen AI-2 production, a reporter strain based on V harveyi is used not only for Gram-negative bacteria, but also for Gram-positive bacteria.325 At present, AI-2 is thought to be a group of compounds synthesized by LuxS from DPD with or without boron. More detailed studies will show the world of AI-2 in more depth. 

UOP introduced the Alkar process for ethylbenzene production in 1966. The Alkar process operates in the vapor-phase with boron trifluoride on an alumina support as the catalyst. By the 1980s, about 15% of the world s ethylbenzene was... 

Hydrogen and helium are the most abundant elements in the universe, relics of the earliest moments in element production. However, it is the stellar production process that led to the characteristic cosmic abundance of the elements (Fig. 1.1). Lithium (Li), beryllium (Be) and boron (B) are not very stable in stellar interiors, hence the low abundance of these light elements in the universe. Carbon (C), nitrogen (N) and oxygen (O) are formed in an efficient cyclic process in stars that leads to their relatively high abundance. Silicon (Si) is rather resistant to photodissociation (destruction by light) in stars, so it is also abundant and dominates the rocky world we see about us. 

Recent laboratory studies and field operations have demonstrated the excellent performance of a macroreticular boron-specific ion-exchange resin, Amberlite XE-243, for deborat-ing several process streams, sea water, and irrigation water. One large plant is now operating successfully on sea water. Further studies on this product are currently in progress in several areas throughout the world. 

No statistical figures are available on the production levels of boron nitride, but a reliable estimate was about 220 metric tons in 1993 for the western world, one-third each of which was produced in the United States, Europe, and Japan... 

Boron carbide was first produced and identified at the end of the nineteenth century and for many years remained a laboratory curiosity. The structure and composition were tentatively determined in 1934.l l It was not until the end of World War II that the first major applications were developed particularly in the nuclear industry. Production was estimated to reach 40 million in 1994.02]... 

The oxide B Oj may be reduced by magnesium at high temperature to a product with a boron content of 86-88%. It is often called amorphous boron . Industrially, boron with high purity is manufactured by reduction of boron trichloride with hydrogen. The annual production of boron, amorphous and elementary together, in the world is about 50 toimes. 

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