2 results about "Mercury oxidation" patented technology

The present application belongs to the field of environmental protection, and particularly relates to a regeneration method for improving the synergistic mercury oxidation performance of a vanadium-poisoned catalyst. The present application provides a method for removing the vanadium-poisoned catalyst in two steps in the regeneration process. Vanadium crystallization is extracted by oxalic acid, and the catalyst is activated by a process in combination with sulfuric acid. On this basis, the loading of molybdenum and cerium is realized by a one-step method, which increases the mercury oxidation performance. Moreover, the oxalic acid extract can be reused, and the vanadium element is recycled in the whole process through the action of sulfuric acid, which has the characteristics of green chemistry.

The application discloses a method for selectively recovering gold from gold leaching solution by copper-ammonia catalytic thiosulfate method and simultaneously removing impurities from the solution, which comprises the following steps: performing constant potential electrodeposition on the gold leaching solution obtained by leaching gold-containing raw materials by the copper-ammonia catalytic thiosulfate method, and controlling the potential of the working electrode to be in the range of-0.5V to-0.4V relative to the mercury / mercury oxide electrode and the pH to be in the range of 9.5 to 10.5. In the potential and pH range, gold ions are preferentially reduced to elemental gold and deposited on the cathode, while copper ions are not deposited, realizing high selective separation and recovery of gold. More importantly, thiosulfate will not be oxidized, and the impurity sulfur oxyanions generated by the oxidation of thiosulfate during the leaching process will be converted into thiosulfate, realizing the removal of impurities from the leaching solution and the regeneration of the gold leaching agent. The process flow is short, the operation is simple, and the environment is friendly.