V. Reclamation Reuse of Foundry Waste Products - (PPT)

摘要

The Acid Demand Value test: The add demand value is important because it displays the amount of alkaline materials that should not be present in washed and classified foundry silka sand. Minerals such as limestone and shell, (CaCO_3), dolomite Ca/Mg CO_3, Lime CaO. The importance of the Acid Demand in testing should not be overlooked as it reveals various carbonates and salts that may be missed with a standard pH test. A high ADV will significantly shorten bench life in the cold box system and lead to pinhole defects in castings due to the production of CO_2 gas evolution. Typical Values for Queensland silica Sands are: FSD 710M 0-4ml, Rouse Channel Sand 15-40ml. The Best Value is 0 and a usable maximum value is IS. The acid demand test can be obtained by the use of hydrochloric acid or Sulphuric Acid as per the BCIRA Broadsheet 210-4 (1983).