Abstract: Provided is a process for recovery of gold from gold-bearing raw materials comprising (a) leaching said gold-bearing raw material in a chloride containing leaching solution containing a total concentration of less than 120 g/L of halide ions, whereby the total concentration of chloride ions is less than 120 g/L of to dissolve gold and to obtain a leach solution comprising gold in solution; and simultaneously contacting the leach solution comprising gold in solution with a re-sorptive material to obtain a leach solution comprising gold-bearing re-sorptive material; and (b) recovering gold and optionally silver from the said gold-bearing re-sorptive material.

Abstract: The invention relates to a method for recovering energy and water from pressure oxidation flash steam where first flash steam directly obtained from a flash vessel is contacted with a first recirculating condensate having a first low condensate temperature to condense at least part of the water vapor in the first dirty flash steam and simultaneously to heat the first recirculating condensate to obtain a first recirculating condensate having a first high condensate temperature and a first vent steam. The invention further relates to a pressure oxidation arrangement adapted for use in the method.

Abstract: Provided is a process for recovery of gold from gold-bearing raw materials comprising (a) leaching said gold-bearing raw material in a chloride containing leaching solution containing a total concentration of less than 120 g/L of halide ions, whereby the total concentration of chloride ions is less than 120 g/L of to dissolve gold and to obtain a leach solution comprising gold in solution; and simultaneously contacting the leach solution comprising gold in solution with a re-sorptive material to obtain a leach solution comprising gold-bearing re-sorptive material; and (b) recovering gold and optionally silver from the said gold-bearing re-sorptive material.

Abstract: The invention relates to a method of recovering energy and water from pressure oxidation flash steam comprising a step wherein a first flash steam directly obtained from a flash vessel is contacted with a first recirculating condensate having a first low condensate temperature to con-dense at least part of the water vapour comprised in the said first dirty flash steam on the first recirculating condensate and simultaneously to heat the said first recirculating condensate to obtain a first recirculating condensate having a first high condensate temperature and a first vent steam. The invention further relates to a pressure oxidation arrangement adapted for recovering energy from pressure oxidation flash steam and to a use of high temperature condensate and to a use of a direct contact condenser for recovery of energy and water from a pressure oxidation flash steam.

Abstract: A method for leaching a sulfidic metal concentrate in hydrometallurgical production of metal in a leaching process from which hot water vapor containing off-gas is conducted out and to which an acid solution warmed up to an elevated temperature is conducted. The acid solution is warmed up to an elevated temperature by bringing off-gas of the leaching step into direct contact with the acid solution.

Abstract: A method and apparatus for converting an iron-bearing residue generated in a hydrometallurgical process that contains small amounts of soluble heavy metals into a stable form by means of a neutralizing agent. The residue is elutriated and the elutriated residue is fed into at least one stabilization or homogenization reactor, into which a neutralizing agent is also routed, and the homogenous mixing together of the residue and neutralizing agent takes place by means of a helix mixer, where the ratio of the diameter of the mixer to the diameter of the reactor is 0.75-0.99.

Abstract: A method for leaching a sulfidic metal concentrate in hydrometallurgical production of metal in a leaching process from which hot water vapor containing off-gas is conducted out and to which an acid solution warmed up to an elevated temperature is conducted. The acid solution is warmed up to an elevated temperature by bringing off-gas of the leaching step into direct contact with the acid solution.

Abstract: A method and apparatus for converting an iron-bearing residue generated in a hydrometallurgical process that contains small amounts of soluble heavy metals into a stable form by means of a neutralising agent. The residue is elutriated and the elutriated residue is fed into at least one stabilisation or homogenisation reactor, into which a neutralising agent is also routed, and the homogenous mixing together of the residue and neutralising agent takes place by means of a helix mixer, where the ratio of the diameter of the mixer to the diameter of the reactor is 0.75-0.99.