Abstract: A process and system for recovery of gold from an ore having the steps of i) providing the ore containing the gold to be recovered, ii) leaching the ore in an oxidative chloride medium, including a nitrogen species to produce a solution comprising gold; and iii) recovering the gold from the solution. The gold in a preferred embodiment is recovered from refractory and carbonaceous ores.

Abstract: A process and system for recovery of gold from an ore having the steps of i) providing the ore containing the gold to be recovered, ii) leaching the ore in an oxidative chloride medium, including a nitrogen species to produce a solution comprising gold; and iii) recovering the gold from the solution. The gold in a preferred embodiment is recovered from refractory and carbonaceous ores.

Abstract: A process and system for recovering titanium dioxide and other value metals from a titanium bearing solid is disclosed. The process includes leaching the solid in hydrochloric acid to produce a leachate comprising undissolved solids and a leach solution comprising the titanium dioxide and the value metals, wherein the hydrochloric acid concentration is maintained above a value required to maintain the titanium dioxide and the value metals dissolved in the leach solution at atmospheric pressure. The leachate is separated into the leach solution and the undissolved solids. The concentration of hydrochloric acid concentration in the leach solution is reduced to recover titanium dioxide by hydrolysis and precipitation to produce a titanium dioxide rich slurry. In a preferred embodiment, HCl is recovered with a matrix solution.

Abstract: A method for recovering hydrochloric acid and metal oxides from a chloride liquor is described. The method uses a chloride liquor including the metal and mixing the liquor and a matrix solution to produce a reaction mixture, wherein the matrix solution assists oxidation/hydrolysis of the metal with HCl production. In a preferred embodiment the matrix solution includes zinc chloride in various stages of hydration and an oxygen containing gas is added to the mix. A method where the improvement is the mixing of a liquor and a matrix solution where the solution assists hydrolysis of the metal with HCl production is also disclosed. The reactor is a column reactor in a preferred embodiment. Further disclosed is the method of using the matrix solution and a reactor for recovering hydrochloric acid and for oxidizing/hydrolysis of a metal.