Deep-Well Disposal of Steel Pickling Acid

Abstract Several aspects of subsurface disposal of waste pickle liquor (WPL) are presented from a survey conducted by Bureau of Mines engineers. Both hydrochloric and sulfuric acid waste pickle liquors are being injected into deep wells. These wastes require that acid-resistant material be used in storage, filtering, and pumping operations. In Illinois and Indiana, WPL is injected into the Cambrian age Mt. Simon sandstone formation. The Mt. Simon sandstone in these States ranges up to 1,800 ft thick and has an effective porosity of 12 percent and an absolute permeability ranging from 75 to 400 md. The average depth of WPL disposal wells is 4,000 ft, and injection is usually by gravity flow at rates as high as 2,000 BPD. Completion of the disposal wells deviates from standard petroleum engineering practice in several ways. Extra strings of practice in several ways. Extra strings of casing are cemented to the surface to offer greater protection of fresh water zones, water is pumped through the annulus of the injection tubing and casing for protection against corrosion, and electrodes are used at the bottom of the casing to monitor the acidity of the fluid in the annulus. Introduction The steel industry has adapted the petroleum technology of subsurface disposal petroleum technology of subsurface disposal of brines to the disposal of waste steel pickling acid. The underground injection pickling acid. The underground injection of waste pickle liquor (WPL) by the steel manufacturing companies commenced in 1965 as the cost of surface treatment and emphasis on surface pollution from waste chemicals increased. Prior to 1965, the WPL was treated by neutralization, sedimentation, and sludge disposal. Many acres of valuable company land had to be used for sludge disposal. The steel companies that have turned to subsurface waste disposal to solve their waste acid disposal problem are located in the North central and Eastern states as shown in Fig. 1. Hartman states that subsurface disposal of WPL has proved to be economically feasible for the steel industry. The capital investments maintenance, and operating costs of subsurface injection systems are each one-third to one-fifth the cost of surface treatment and disposal. When properly designed, maintenance is negligible and the system can be operated under automatic control for an indefinite period. In addition, very little plant area is required for subsurface waste disposal systems.