Patent ID: 8888890

Claim:
A redox ore leaching treatment method employing a sulfurous acid solution, which can be used to treat a variety of different ores containing one or more of the following gold, silver, copper, lead, cobalt, nickel cadmium, chromium, antimony, zinc, aluminum, and mercury, but only one need be treated, comprising: a. determining the composition of ore and its microbes to be acid leached and whether the ore requires acid oxidation, reduction, or both, b. injecting sulfur dioxide (SO 2 ) into water to be treated to provide H + , SO 2 , SO 3 = , HSO 3 − , dithionous acid (H 2 S 2 O 4 ), and other sulfur intermediate reduction products forming a sulfur dioxide treated leaching solution to acid leach heavy metals from ores and provide nutrients to feed bioleaching microbes to eat ores to release heavy metals into solution, c. monitoring and adjusting the sulfur dioxide treated leaching solution reduction potential to form either an acid oxidizing or acid reducing leaching solution or both by altering the oxidation and reduction states of the sulfites/bisulfites/dithionous acid, and SO 2 between −0.37 and −0.14 volts at 25° C. at 1 molal H + for leaching a particular ore by either: i. adding additional sulfur dioxide (SO 2 ) and/or other acid in the presence of oxygen to insure that electrical conductivity levels of the sulfur dioxide treated water are sufficient to accept electrons by the sulfur dioxide, sulfites, bisulfites, and dithionous acid to form an oxidizing leaching solution, or ii. adding the sulfur dioxide without the addition of additional acid or oxygen to insure electrical conductivity levels of the sulfur dioxide treated water are sufficient for release of electrons from the sulfur dioxide, sulfites, bisulfites, and dithionous acid to form a reducing leaching solution, d. monitoring and adjusting the pH of the sulfur dioxide treated leaching solution at a pH between 0.5 and 4.5 to provide sulfites and bisulfites, dithionous acid and SO 2 to feed ore leaching microbes to release heavy metals, and e. selectively employing either the acid oxidizing leaching solution or the acid reducing leaching solution with altered oxidation and reduction states of the sulfites/bisulfites/dithionous acid and SO 2 for ore leaching microbes and acid leaching to produce a soluble metal salt enriched leachate for chemical and bioleaching metals recovery.