Abstract: A brake adjustment indicator for indicating when an air brake is out of adjustment during a visual inspection of the air brake includes a collar including a perimeter wall defining a bore. The bore of the collar receives a push rod of an air brake to position the collar around the push rod. The collar is inserted into an air piston housing when the air brake is released. At least a portion of the collar extends from the air piston housing to indicate an amount of adjustment needed for the air brake when the air brake is engaged. A flange is coupled to and extends radially outwardly from the collar to abut the air piston housing and inhibit debris entering the air piston housing adjacent to the collar. The flange has an aperture aligned with the bore of the collar to receive the push rod.

Abstract: In one aspect the present invention provides a method of recovering gold from each of at least two different refractory gold-bearing sulfidic mineral materials. A first mineral material is subjected to biooxidation pretreatment to release gold locked within sulfide minerals. The biooxidation produces an acidic biooxidation liquor effluent that contains significant dissolved iron in the ferric form. All or a portion of the biooxidation liquor effluent is used as an acidic treatment liquid to treat the second mineral material, which contains acid-consuming minerals. During the treatment, acid-consuming minerals react with the acidic solution, raising solution pH and resulting in reduced solubility and precipitation of dissolved iron and other metals. Also during the treating, sulfides in the second mineral material or oxidized, thereby releasing gold for subsequent recovery.

Abstract: In one aspect the present invention provides a method of recovering gold from each of at least two different refractory gold-bearing sulfidic mineral materials. A first mineral material is subjected to biooxidation pretreatment to release gold locked within sulfide minerals. The biooxidation produces an acidic biooxidation liquor effluent that contains significant dissolved iron in the ferric form. All or a portion of the biooxidation liquor effluent is used as an acidic treatment liquid to treat the second mineral material, which contains acid-consuming minerals. During the treatment, acid-consuming minerals react with the acidic solution, raising solution pH and resulting in reduced solubility and precipitation of dissolved iron and other metals. Also during the treating, sulfides in the second mineral material or oxidized, thereby releasing gold for subsequent recovery.