Abstract: In some embodiments, the present disclosure provides a monitoring device that is capable of autonomously measuring in situ radiation activity in the subsurface, such as tritium activity. In particular embodiments, the device includes a water decomposition reactor which decomposes an aqueous sample, such as a reactor which includes a reactive metal alloy, such as NaK. In further embodiments, the device includes a detector and a hydrogen getter. The hydrogen getter removes hydrogen and tritium gas from the detector, allowing multiple measurements to be made without removal or servicing of the device. The present disclosure also provides instruments having detector and reactor portions separated by an isolation valve. Particular embodiments of the device include a high pressure valve, such as a rotary valve, for selectively placing the device in communication with a sample source, such as liquid in a well.

Abstract: Arsenic, in the form of As.sub.2 O.sub.3, is recovered from arsenical ores or concentrates by leaching with a hot acidic ferric salt solution to extract arsenic, followed by cooling the pregnant leach solution to crystallize As.sub.2 O.sub.3. Leaching of some ores or concentrates is facilitated by addition of silver sulfate or mercuric sulfate to catalyze the leaching reaction.

Abstract: A method for the separation of bismuth from a complex chloride solution obtained by leaching with chloride reagents ores containing bismuth and high concentrations of other metals comprising adding to said complex chloride solution at least a stoichiometric amount of a precipitating agent selected from the group consisting of hexamminecobalt (III) salts and hexamminechromium (III) salts soluble in said solution to precipitate said bismuth as a hexamminecobalt (III) bismuth salt or a hexamminechromium (III) bismuth salt and separating said precipitate from said solution.

Abstract: A rapid, energy efficient, low cost, nonhazardous method for the selective removal of mercury from mercury-containing metal cyanide solutions, particularly the cyanide solutions resulting from the cyanidation of gold ore and the like, wherein a reactive sulfide is admixed with the solution for a time sufficient to form an insoluble mercuric sulfide precipitate. The mercuric sulfide precipitate is then separated from the metal cyanide solution by filtration or other conventional means.

Abstract: A low cost, effective method for removing heavy metal ions from aqueous solution which utilizes a porous, high surface-to-weight ratio siliceous adsorbent comprises the steps of activating the siliceous adsorbent, which is preferably a kaolin clay leach residue, with a basic salt of an alkali metal to incorporate alkali ions into the siliceous adsorbent and contacting the heavy metal ion-containing solution with the activated adsorbent whereby the heavy metal ions exchange with the alkali ions to remove the heavy metal ions from solution. The heavy metal ion loaded adsorbent may be stripped for subsequent reuse or, alternatively, utilized for flux in base metal smelting and the like.

Abstract: Uranium is recovered from refractory carbonaceous-sulfidic ores or concentrates by leaching with nitric acid, followed by sorption on an ion exchange resin. In addition, the nitric acid leach solution is regenerated and recycled.