High-Pressure Synthetic Diamond Production

The major producers of high-pressure synthetic diamond include General Electric in the U.S., de Beers in South Africa, Ireland and Sweden, Sumitomo and Tome in Japan, and plants in the former Soviet Union, Czechoslovakia, Germany, Korea, and China. 

The growth of high-pressure synthetic diamond is shown in Fig. 12.8.( i The market is now of considereible size with an estimated production of seventy tons in 1992, all for industrial applications. The largest consumer is the U.S., closely followed by Japein and Western Europe. 

High-pressure synthetic diamond, because of its high purity and uniformity, has taken an increasing share of the industrial diamond market and has replaced natural diamond in many areas. 

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NATURAL AND HIGH-PRESSURE SYNTHETIC DIAMOND PRODUCTION... 

Figure 12.8. World production of high-pressure synthetic diamond.

First production of high-pressure synthetic diamond in Sweden, the U.S. and the Soviet Union... 

Synthetic Diamond. In 1955 the General Electric Company announced the successful production of diamonds (see Carbon, diamond, synthetic) from graphite under very high pressure and temperature ia the presence of a metal catalyst. It was later reported that a Swedish company, Allmana Svenska Electriska AB (ASEA), had succeeded ia ptoduciag diamond ia 1953 (35). 

With the technical development achieved in the last 30 years, pressure has become a common variable in several chemical and biochemical laboratories. In addition to temperature, concentration, pH, solvent, ionic strength, etc., it helps provide a better understanding of structures and reactions in chemical, biochemical, catalytic-mechanistic studies and industrial applications. Two of the first industrial examples of the effect of pressure on reactions are the Haber process for the synthesis of ammonia and the conversion of carbon to diamond. The production of NH3 and synthetic diamonds illustrate completely different fields of use of high pressures the first application concerns reactions involving pressurized gases and the second deals with the effect of very high hydrostatic pressure on chemical reactions. High pressure analytical techniques have been developed for the majority of the physicochemical methods (spectroscopies e. g. NMR, IR, UV-visible and electrochemistry, flow methods, etc.). 

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