Materials Balance for Dyes and Pigments from Benzidine and Three Benzidine Derivatives

摘要

The processes for and losses resulting from the manufacture of dyes and pigments are presented. Consumption profiles and estimated losses are summarized for bisazobiphenyl (BAB) dyes in the textile, leather, and paper industries and for pigments in the rubber, plastics, printing ink, textile printing, and coatings industries. During dye production, losses occur in by-products, process venting, process losses, product filtration, and transfer and handling of solid dyes. For 1978, about 80% of the total BAB dye used in the textile, paper, and leather industries was incorporated into the final product and 20% was lost to solid waste or wastewater. Losses in wastewater were about 50% greater than in solid waste. During pigment production, losses result from soluble by-products and handling and transfer losses. In 1978, estimated total losses due to handling and transfer of pigments during production were 190,000 to 558,000 lb. The printing ink industry consumed the majority of the total pigment production. In 1978, about 75% of the total pigment used in the five industries was incorporated into the final product and 25% was lost to wastewater or solid waste. Essentially all of the pigment loss was as solid waste with very small quantities in wastewater.