Mining for lost silver.To recover silver from used X-ray film, Haruo Ishikawa Ishikawa (ēshē`käwä), prefecture (1990 pop. 1,164,627), 1,619 sq mi (4,193 sq km), central Honshu, Japan. The capital is Kanazawa. There are wooded mountains in the interior and fertile plains along the coast. Rice, machinery, lumber, raw silk, and lacquer ware are produced., a chemist at Japan's University of Osaka Osaka (ō`säkä), city (1990 pop. 2,623,801), capital of Osaka prefecture, S Honshu, Japan, on Osaka Bay, at the mouth of the Yodo River. One of Japan's largest cities and principal industrial and commercial centers, Osaka is the focal point of a chain of industrial cities (called the Hanshin or Kinki Prefecture, and his colleagues have devised a biological technique to break down the film's emulsion, which holds the silver particles in place. The scientists use a bacterial enzyme to attack the film's gelatin zinc gelatin a preparation of zinc oxide, gelatin, glycerin, and purified water, used as a topical skin protectant. gel·a·tin or gel·a·tine (j  l coating and release silver particles into solution. The metal then precipitates, Ishikawa reported at last month's meeting of the ICCPBS in Honolulu. This technique produces no pollutants, recovers high-grade silver, and frees up the film's polyester base for recycling, Ishikawa says. To put the method into practice, a pilot plant to reprocess 1 ton of used X-ray film per day is scheduled to open in Osaka within 2 years, he told Science News. Production of X-ray film consumes as much as one-fifth of all silver consumed by industry worldwide. |
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