一、一般概况美国是世界最大的石膏生产国,也是最大的石膏进口国。1983年总产估计为1100万吨以上,比1982年增长16％。化学石膏的用量为50万吨,下降了21％。1983年的总进口量也有大幅度的增长,增长率为23％,达750万吨多。其中68％来自加拿大沿海各省,20％来自墨西哥,12％来自西班牙。 I. General Overview The United States is the world’s largest producer of gypsum and the largest importer of gypsum. The total production in 1983 was estimated at more than 11 million tons, an increase of 16% over 1982. The amount of chemical gypsum used was 500,000 tons, a decrease of 21%. The total import volume in 1983 also increased significantly, with a growth rate of 23%, reaching more than 7.5 million tons. Of these, 68% came from Canada’s coastal provinces, 20% from Mexico and 12% from Spain.