Data are presented showing the types of constructional materials that are resistant to the many corrosive environments in coal-chemical plants. The protection of structural-steel work by paints is viewed from the standpoint of minimizing maintenance costs. To minimize the corrosive attack, copper steels and high-strength low-alloy steels are frequently used for outside structural-steel work, and stainless steels are used for roofing and siding applications.
Coal-handling equipment, and processing equipment such as primary coolers, tar stills, and light-oil stripping-stills are discussed with regard to the mitigation of corrosion through the proper selection of materials and changes in process conditions. Stainless steels such as AISI Types 304 and 316 were found to be economically resistant to corrosive attack in primary coolers, ammonia saturators, tar stills and light-oil recovery equipment, but should be used only in locations where plant corrosion tests have shown the use of these steels to be justified. 8.8.1
