Industrial applications of boron compounds
An inverse proportionality exists between industrial production and scientific interest in boron compounds. Despite the vast amount of research which has been done both academically and industrially, the four simple substances borax, boric acid, calcium borate and sodium perborate account for 99 per cent of the industrial applications in tonnage (production being over two million tons annually) and monetary terms. Several other metal borates, fluoborates and refractory compounds (including alloys) are used at the thousands of tons level, but the academically fascinating boron hydrides, carboranes and related materials, research on which accounts for 99 per cent of publications in boron chemistry during the past few decades, are used hardly at all. There is an inverse proportionality between industrial importance and scientific interest in the case of boron compounds. Borax, or sodium tetraborate, holds practically no attention in the academic world, save possibly as an adjuvant in conducting experiments on other materials. It is a simple salt which dissociates in solution and whose properties have, with a few exceptions, been known for many years. Seldom does a paper devoted to it appear in the scientific literature. Yet its industrial production is well over a million tons a year, placing it in the commodity class, and its uses in technology are legion. On the other hand, innumerable papers are published annually, and have been for the past two or three decades, on the boranes and related compounds. But despite the vast amount of research undertaken in universities and other establishments throughout the world, the uses of these materials are quite negligible; annual 'production' is only on the scale of a minor laboratory reagent and can be measured in kilogrammes. Between these two extremes lie first the simple inorganic compounds calcium borate, sodium perborate, boric acid and boric oxide. World production statistics are difficult to derive, but best estimates of annual tonnages put them at (in thousands of tons) as 750, 400, 120 and 30 respectively. The last three are made from the tonnages of the first and, of course, of borax itself. There is then a range of borates of other metals, several fluoborates and a number of alloys and refractory compounds which are in the one thousand to five thousand tons class. Finally there are several others, mostly inorganic, which are made commercially in smaller quantities but whose