Use of Byproducts in Suspensions
This material discusses the utilization of byproducts and chemical waste in the fertilizer industry, focusing on their application in suspensions. Prepared by the Tennessee Valley Authority (TVA), the report highlights TVA's role in assisting chemical firms in developing uses for byproducts containing valuable plant nutrients. One such example is using spent phosphoric acid, a waste product from aluminum fabricators. This acid, when neutralized by ammonia, can be used to produce mixed liquids containing phosphate. By adjusting the pH, aluminum precipitation can be controlled, resulting in a clear solution suitable for soil application. The report also explores the increasing use of spent sulfuric acid, primarily in regions where it is readily available. Agricultural application is considered an efficient solution for the disposal of this material. Due to the corrosive nature of spent acids and the risk of iron salt crystal formation, precautions such as adding urea and clay suspending agents are recommended to prevent nozzle clogging and improve dissolution. Various sources of spent acid, including galvanizing companies and lead acid battery salvagers, are identified as potential suppliers. The material these companies provide can serve as a source of sulfur and zinc, although the final concentrations may vary. Handling challenges and properly characterizing byproducts to ensure the absence of hazardous substances are emphasized. The report highlights the importance of considering environmental and human safety when using byproducts in agricultural applications. Dilution or proper blending with other materials may be necessary to mitigate any potential risks associated with heavy metal content or toxic substances.
Suspensions, Fertilizer industry