Abstract: An in situ coal gasification process adapted for large scale commercial projects is provided. Techniques are provided to insure establishment of a gasification front over the full seam thickness as each successive injection well in the array is brought on line. This is accomplished by controlling the oxidant introduction in a prescribed manner during the early stages of injection after pneumatic communication between well pairs has been established. Also provided are techniques and standards for avoiding or controlling subsidence and for conducting gasification operations in free water laden seams and in coal seams subject to spontaneous combustion.

Abstract: A process is disclosed which is directed to recovering gold and/or silver values from activated carbon, wherein gold and/or silver has been adsorbed thereon. The process comprises eluting the activated carbon with water soluble alcohols or ketones either alone or with aqueous solutions thereof and a strong base may be added to further facilitate elution.