Bioleaching method and facility

Patent metadata

Field	Value
Publication number	US-2017175223-A1
Application number	US-201515316605-A
Country	US
Kind code	A1
Filing date	Jun 5, 2015
Priority date	Jun 6, 2014
Publication date	Jun 22, 2017
Grant date	—

Abstract

A method for the lagoon-based bioleaching of a metallic ore, wherein the temperature of the suspension containing the metallic ore to be bioleached, a bioleaching consortium and a nutritive substrate of the microorganisms of the consortium is controlled by regulating the flows and the composition of a gas containing oxygen and optionally also CO2 injected into the suspension, the temperature of the suspension being controlled such that it can be maintained within a pre-determined range suitable for bioleaching.

First claim

1 - 15 . (canceled)

16 . Method for bioleaching of a metalliferous ore, said method comprising the following steps:
a) adding, into a basin, a ground metalliferous ore, a medium comprising a bioleaching microbial consortium, and a nutritive medium for the microorganisms of the microbial consortium, b) obtaining a suspension in the basin via at least one stirring system for placing and maintaining the metalliferous ore in suspension in a liquid phase, c) injecting, into the suspension, a gas containing oxygen and optionally carbon dioxide, d) in the suspension, bioleaching of the metalliferous ore by the microbial consortium in order to obtain a released metal, e) recovering a liquid product containing the released metal and consisting of (a) a liquor and (b) a solid residue, wherein the temperature of the suspension is controlled by regulating the flow rates and the composition of the gas injected, as well as optionally the concentration of solids in the suspension, the temperature of the suspension being controlled in such a way as to be maintained in a predetermined range suitable for bioleaching.

17 . Method according to claim 16 , wherein the basin is an open-air basin.

18 . Method according to claim 16 , wherein the gas injected has an O 2 concentration of at least 21% vol O 2 , preferably at least 40% vol and more preferably 50% vol to 100% vol, and optionally a CO 2 concentration from 0% vol to 5% vol, preferably from 1% vol to 3% vol.

19 . Method according to claim 16 , wherein said microbial consortium comprises microorganisms chosen from the species Leptospirillum ferriphilum, Acidithiobacillus caldus and Sulfobacillus benefaciens and the combinations of at least two of said species.

20 . Method according to claim 16 , wherein the suspension is maintained at a pH from 0.8 to 2.5, preferably 1.0 to 1.5.

21 . Method according to claim 16 , wherein the suspension comprises from 15 to 40% solid by weight with respect to the total weight of the suspension, preferably 22 to 38% and more preferably 25 to 35%.

22 . Method according to claim 16 , wherein the stirring system comprises at least one stirrer, preferably at least one floating stirrer, said at least one stirrer being provided with at least one injector for the injection of the gas into the suspension.

23 . Facility for bioleaching via lagooning, comprising:
a basin, preferably an open-air basin, containing a suspension comprising a liquid phase, a ground metalliferous ore, a bioleaching microbial consortium, and a nutritive medium for the microorganisms of the microbial consortium; a stirring system for placing and/or maintaining the metalliferous ore in suspension in the liquid phase, said stirring system comprising a plurality of floating stirrers; at least one injector or the injection of a gas into the suspension, wherein said at least one injector is connected to a source of an oxygenated gas having an O 2 concentration of at least 50% vol and more preferably of at least 85% vol; to a source of a dilution gas having an O 2 concentration from 0 to 21% vol; optionally to a source of carbon gas that can be metabolised, having a CO 2 concentration of at least 50% vol, preferably of at least 75% vol and more preferably of at least 85% vol; the facility also comprising a gas regulator for regulating the flow rate of the oxygenated gas and a dilution-gas regulator for regulating the flow rate of the dilution gas to the at least one injector and optionally also a regulator for regulating the flow rate of the carbon gas that can be metabolised to the at least one injector.

24 . Facility according to claim 23 , wherein the source of dilution gas is a source of nitrogen or a source of air, said source of air being preferably an air compressor.

25 . Facility according to claim 23 , comprising a control unit for the control of the regulator of the oxygenated gas and of the regulator of the dilution gas and optionally also of the regulator of the carbon gas that can be metabolised, in order to regulate the overall gaseous flow rate, the flow rate of O 2 and optionally the flow rate of CO 2 supplied to said at least one injector.

26 . Facility according to claim 25 , comprising at least one system for measuring temperature, for measuring the temperature of the suspension in the basin, the control unit being connected to said system for measuring temperature, the control unit regulating the flow rate of the oxygenated gas and the flow rate of the dilution gas, as well as optionally also the flow rate of carbon gas that can be metabolised, directed to the at least one injector according to the temperature measured by the system for measuring temperature in order to maintain the temperature of the suspension in a predetermined range.

27 . Facility according to one of claim 23 , wherein the basin does not comprise heating or cooling elements.

28 . Facility according to claim 23 , wherein the at least one injector is integrated into the floating stirrers.

29 . Facility according to claim 23 , wherein the microbial consortium comprises microorganisms chosen from the species Leptospirillum ferriphilum, Acidithiobacillus caldus and Sulfobacillus benefaciens and the combinations of said species.

30 . Method for regulating temperature, for a bioleaching suspension, said suspension comprising a metalliferous ore, a bioleaching microbial consortium, and a nutritive medium for the microorganisms of the consortium, wherein in said method, the temperature of the suspension is controlled by regulating the flow rate and the composition of a gas, containing oxygen and optionally carbon dioxide, that is injected into said suspension, as well as optionally by regulating the concentration of solids in the suspension, in such a way that the temperature of the suspension is maintained in a predetermined range.

Assignees

• Air Liquide
• Brgm
• Milton Roy Europe

Inventors

• Guezennec Anne-Gwénaëlle
• Ibarra Dominique
• Jaillet Marie
• Menard Yannick
• Morin Dominique
• Pubill Melsio Anna
• Savreux Frédéric
• D'Hugues Patrick

Classifications

• Y02P10/20

  Recycling · CPC title

• C22B15/0065

  Leaching or slurrying (with organic compounds C22B3/16) · CPC title

• C22B3/18 Primary

  with the aid of microorganisms or enzymes, e.g. bacteria or algae · CPC title

• C22B23/0407

  Leaching processes · CPC title

• C22B11/04

  by wet processes (extraction of metal compounds by leaching in organic solutions C22B3/16; treatment or purification of solutions by liquid-liquid extraction C22B3/26) · CPC title