American MicroTrace, CoZinCo and WyZinCo have been acquired by Tetra Technologies and operate under the name Tetra Micronutrients. In 1998, the WyZinCo site in Cheyenne, Wyo., was expanded from 12,000 to 24,000 tons. In 1999, the 18,000-ton zinc sulfate plant of CoZinCo in Salida, Colo., was closed. Several other companies produce granular and solution zinc sulfate containing varying percentages of zinc. Demand equals production plus imports, which were 7,800 short tons in 1997 and 11,400 short tons in 1998, minus exports of 6,400 short tons in 1997 and 4,800 short tons in 1998.
Market prices are at a substantial discount from list prices.
It is applied to pecans, deciduous fruits, peanuts, cotton, corn and citrus, and added to feeds for swine and poultry. In recent years, some of the fertilizer segment's gains have come at the expense of zinc oxysulfate, produced from steel furnace fly ash. Fear of chromium and other heavy metals caused some oxysulfate to be displaced in the fertilizer market. Recent industry consolidation and plant rationalization has strengthened the industry. Zinc sulfate's high solubility in aqueous systems makes it popular for agricultural applications, but other uses are expected to remain stagnant.