WO2008036985A2 - Bioleaching process control in a stirred tank - Google Patents
Bioleaching process control in a stirred tank Download PDFInfo
- Publication number
- WO2008036985A2 WO2008036985A2 PCT/ZA2006/000108 ZA2006000108W WO2008036985A2 WO 2008036985 A2 WO2008036985 A2 WO 2008036985A2 ZA 2006000108 W ZA2006000108 W ZA 2006000108W WO 2008036985 A2 WO2008036985 A2 WO 2008036985A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- reactor
- slurry
- gas
- sulphide
- rate
- Prior art date
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
- C22B3/18—Extraction of metal compounds from ores or concentrates by wet processes with the aid of microorganisms or enzymes, e.g. bacteria or algae
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
- C22B3/02—Apparatus therefor
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Definitions
- This invention relates generally to a bioleaching process and more particularly is concerned with controlling this type of process, when implemented in a stirred tank reactor, to reduce energy consumption.
- Bioleaching in stirred tank reactors is used to oxidise refractory sulphidic gold concentrates and copper sulphide concentrates and is also applicable to nickel and zinc sulphides.
- the electrical power consumed in the compression of air or oxygen, delivered to a reactor, and the energy requirement for dispersing the gas in the reactor represent a substantial operating cost.
- slurry consisting of water, nutrients and a sulphide concentrate, is fed to a reactor in which appropriate microorganisms oxidise ferrous iron and sulphide. This oxidation process requires oxygen.
- the oxygen is delivered to the reactor in gaseous form as air, oxygen enriched air or oxygen.
- This gas is sparged into the reactor below a high solidity downward pumping agitator or a radial type impeller. This device shears the slurry and the incoming gas stream is broken into small bubbles. This greatly increases the surface area of the gas stream and the rate at which oxygen is transferred into the slurry is increased.
- the rate of transfer of oxygen is proportional to: a) the amount of gas added, unless the gas rate exceeds the impeller's ability to disperse it; b) the partial pressure of oxygen within the gas; and c) the amount of power transferred to the slurry by the agitator.
- the rate of transfer of oxygen is however inversely proportional to the amount of dissolved oxygen within the slurry.
- the rate of oxygen consumed by reaction is dependent on the rate at which sulphide is fed to the reactor and this, in turn, can be affected by the throughput or by the grade of the concentrate.
- a typical bioleaching process usually functions within a number of boundary conditions such as minimum and maximum dissolved oxygen concentrations, an agitator's limitation on gas dispersion, and so on. Within these boundary conditions there are optimum conditions at which to operate the process depending on the plant's location, its size and its oxygen demand. It is normal practice to design a plant for what are estimated to be feed conditions over a set portion of the plant's lifetime.
- FIG. 1 illustrates energy consumption per kilogram of sulphide treated as a function of agitator input power for a thermophile plant that includes primary and secondary reactors.
- a lower curve gives the aforementioned relationship for full sulphide tonnage delivered to the plant while an upper curve gives the relationship when the sulphide feed tonnage is reduced by 50% and the gas delivery power is reduced to compensate. It is evident that despite reducing the rate at which gas is supplied to the plant, to compensate for a reduced sulphide feed rate, the energy consumed per unit sulphide treated increases by from 19% to 39% depending on the amount of agitator power supplied.
- Figure 2 includes similar graphs for an air-supplied mesophile plant of the same duty.
- a lower curve is for full sulphide tonnage, and an upper curve is for half sulphide tonnage.
- the energy cost per unit sulphide treated, arising from a reduction in sulphide tonnage, increases by from 26% to 60%.
- the invention is concerned with a control technique which aims to reduce the energy consumption per unit sulphide treated under the aforementioned conditions.
- the invention provides a method of conducting a bioleaching process which includes the steps of feeding a sulphide mineral slurry to a reactor, sparging the slurry in the reactor with a gas, agitating the slurry in the reactor with a motor-driven agitator, causing biooxidation of the sulphide mineral to take place, and controlling the rate of supply of the sparging gas to the reactor and of the energy supplied to the motor in response to at least one of the following: measured oxygen demand; and inferred oxygen demand.
- Figures 1 and 2 relate to existing situations and have already been described
- Figure 3 reflects energy consumption per unit sulphide for the compressors and agitators of a thermophile plant at normal sulphide grade, half sulphide grade, and half sulphide grade with reduced agitation power, respectively;
- Figure 4 reflects energy consumption per unit sulphide for the compressors and agitators of a thermophile plant at full tonnage, two-thirds tonnage, and two-thirds tonnage with reduced agitator power, respectively and;
- FIG. 5 is a block diagram representation of the manner in which the method of the invention is implemented.
- FIG. 5 of the accompanying drawings is a block diagram representation of a plant 10 in which a stirred tank bioleaching sulphide oxidation process is carried out in accordance with the principles of the invention.
- the plant includes a series of stirred tank reactors although only one tank, designated 12, is shown in Figure 5.
- the tank includes an agitator or impeller 14 (these terms are used interchangeably in this specification) which is driven by means of an electrical motor 16, using techniques which are known in the art. Electrical energy is supplied from a source 18 to the motor.
- a gas source 20 is used to introduce sparging gas into diff users or similar emission devices 22 at a lower end of the tank 12.
- the gas which is introduced may be air, oxygen enriched air or substantially pure oxygen.
- the source 20 may include one or more compressors, air pumps or the like. Conventional devices may be used in this respect.
- the rate at which gas is supplied by the source to the tank is monitored by a sensor 24 which relays this information to a control computer 26.
- the controller receives data input from other sources and is capable of exerting a control function so as to vary the rate at which the source supplies gas to the reactor.
- a slurry 28 is introduced into the tank in a controlled manner.
- the slurry comprises water, nutrients and a mineral sulphide concentrate.
- the use of the principles of the invention is not restricted to a particular mineral type and typically these principles may be used in processes for the recovery of gold, copper, nickel and zinc.
- the tank in question is not necessarily a primary reactor, but may be a secondary reactor receiving the product from a primary reactor for further oxidation.
- the tank 12 contains a self-sustaining population of microorganisms which act as catalysts for the oxidation of ferrous iron and sulphide. These reactions require oxygen and, as indicated, this is applied from the gas source 20.
- the level of dissolved oxygen within the slurry, in the tank 12, is monitored by means of a suitable sensor 30.
- the off-gas composition is measured by means of a sensor 32.
- the oxygen demand is either calculated from data derived from the outputs of the gas supply 20 as detected by the sensor 24, and the sensor 32, or is estimated by using a suitable algorithm and the outputs of the agitator power 18, the gas supply 20 and the sensor 30, or the oxygen uptake rate is manually measured by an operator.
- the estimated or measured oxygen uptake rate is used in a suitable algorithm to establish the most efficient level at which energy should be supplied to the motor 16, taking into account the overall power used to supply gas to all the tanks in the plant and any limitation of gas supply.
- the algorithm can be implemented automatically via the control computer 26 or manually by means of signals input by a trained operator.
- the total power consumption for all tank agitators and gas supply compressors is measured and recorded to track usage.
- An objective of the invention is to increase the efficiency of the oxidation process by controlling power which is input to the agitator and the quantity of gas delivered to the slurry.
- Figure 3 shows three points of operation, namely a normal operating point 40, a point 42 which depicts the effect if the sulphide grade drops by half and the agitator power is not lowered, and a point 44 which depicts the effect if the sulphide grade drops by half and the agitator power is reduced by an appropriate amount.
- Figure 3 shows that at half sulphide grade operation the energy cost, which is the cost of operating the motor 16 and the gas source 20, is about 35% more if the energy supply to the agitator is not reduced. However if this energy level is reduced the energy consumption per unit sulphide treated is about 21% more. [0026] If the sulphide grade is reduced then the efficiency of the oxidation process is decreased in the manner which has been described in connection with Figures 1 to 3. It is to be borne in mind that in a biological plant a decrease in grade does not necessarily allow for a decrease in process retention if the same percentage valuable mineral recovery is to be achieved.
- FIG. 4 shows the plant efficiency for normal operation (point 48) and operation at a level of two-thirds design capacity with (point 50) and without (point 52) a reduction in the agitator energy consumption.
- the reduction in concentrate feed rate results in a 24% increase in energy per unit sulphide treated if only the power of the gas source 20 is reduced.
- optimising control is exerted via the processor 30 on the motor 16 and on the source 20 to control agitation energy and the aeration energy then the increase in energy consumption per unit sulphide treated is of the order of 14%.
- the invention seeks to optimise the operation of the bioleaching section of a plant. Aspects relating to energy control can be implemented by making use of variable speed drives which, typically are electronically based. It is also possible to use measured or inferred oxygen utilisation rates together with mathematical correlation and models to optimise the whole process or individual reactor requirements. In the latter respect it should be borne in mind that the invention has been described with reference to a single reactor or tank but, in practice, a series of tanks are used.
- the invention thus allows for an improvement in overall efficiency with a corresponding reduction in energy consumption.
- a reduction in energy consumption can be achieved by an interplay between the energy input to the motor and the energy input to the gas source. The aggregate of the energy which is input is then optimised, as opposed to optimising the energy consumption of the motor.
- the information which is generated by the process can be utilised automatically or can be made available to control personnel who can then take appropriate manually implemented control steps.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Mechanical Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Organic Chemistry (AREA)
- Environmental & Geological Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Metallurgy (AREA)
- Materials Engineering (AREA)
- Biochemistry (AREA)
- Biotechnology (AREA)
- Microbiology (AREA)
- Physical Or Chemical Processes And Apparatus (AREA)
- Apparatus Associated With Microorganisms And Enzymes (AREA)
Abstract
Description
Claims
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU2006347613A AU2006347613B2 (en) | 2005-09-15 | 2006-09-15 | Bioleaching process control |
EP06851599A EP1937858A2 (en) | 2005-09-15 | 2006-09-15 | Bioleaching process control |
EA200800805A EA013851B1 (en) | 2005-09-15 | 2006-09-15 | Bioleaching process control |
CA002628125A CA2628125A1 (en) | 2005-09-15 | 2006-09-15 | Bioleaching process control |
AP2008004397A AP2270A (en) | 2005-09-15 | 2006-09-15 | Bioleaching process control. |
US12/048,436 US20080173133A1 (en) | 2005-09-15 | 2008-03-14 | Bioleaching Process Control |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
ZA200507453 | 2005-09-15 | ||
ZA2005/07453 | 2005-09-15 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/048,436 Continuation US20080173133A1 (en) | 2005-09-15 | 2008-03-14 | Bioleaching Process Control |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2008036985A2 true WO2008036985A2 (en) | 2008-03-27 |
WO2008036985A3 WO2008036985A3 (en) | 2008-06-26 |
Family
ID=39201371
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/ZA2006/000108 WO2008036985A2 (en) | 2005-09-15 | 2006-09-15 | Bioleaching process control in a stirred tank |
Country Status (9)
Country | Link |
---|---|
US (1) | US20080173133A1 (en) |
EP (1) | EP1937858A2 (en) |
CN (1) | CN101341264A (en) |
AP (1) | AP2270A (en) |
AU (1) | AU2006347613B2 (en) |
CA (1) | CA2628125A1 (en) |
EA (1) | EA013851B1 (en) |
WO (1) | WO2008036985A2 (en) |
ZA (1) | ZA200803138B (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2014169325A1 (en) * | 2013-04-15 | 2014-10-23 | Bhp Billiton Olympic Dam Corporation Pty Ltd | Method for processing ore |
WO2018049487A1 (en) * | 2016-09-19 | 2018-03-22 | Bhp Billiton Olympic Dam Corporation Pty Ltd | Integrated hydrometallurgical and pyrometallurgical method for processing ore |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9518922B2 (en) | 2011-08-01 | 2016-12-13 | Endress+Hauser Conducta Gmbh+Co. Kg | Arrangement for in situ measurement of at least the oxygen content within a solids heap |
CN102534210A (en) * | 2012-01-17 | 2012-07-04 | 江西理工大学 | Metal ore heap leaching, anaerobic enrichment transformation and biological leaching extraction process |
CN102703687B (en) * | 2012-06-15 | 2014-02-26 | 东华大学 | Temperature controllable device for selectively leaching minerals by bacteria |
RU2552207C1 (en) * | 2013-12-20 | 2015-06-10 | Федеральное государственное автономное образовательное учреждение высшего профессионального образования "Национальный исследовательский технологический университет "МИСиС" | Method of controlling process of biooxidation of sulphide concentrates |
CN106755990A (en) * | 2016-11-24 | 2017-05-31 | 贵州大学 | A kind of leaching tanks |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SU795960A1 (en) * | 1979-02-22 | 1981-01-18 | Всесоюзный Научно-Исследовательс-Кий И Проектно-Кнструкторскийинститут По Автоматизации Предп-Риятий Промышленности Строитель-Ных Материалов | Apparatus for regulating mixing process in rotor-type mill ajitator |
US4551663A (en) * | 1984-08-01 | 1985-11-05 | Ludlow Industries, Inc. | Level control device |
US5007620A (en) * | 1986-02-07 | 1991-04-16 | Envirotech Corporation | Apparatus for biological processing of metal-containing ores |
JPH1158236A (en) * | 1997-08-20 | 1999-03-02 | Nippei Toyama Corp | Slurry circulating device and wire saw using it |
PE20020912A1 (en) * | 2000-11-25 | 2002-10-19 | Billiton Sa Ltd | BIOPRODUCT PRODUCTION |
WO2002081761A2 (en) * | 2001-04-10 | 2002-10-17 | Billiton Sa Limited | Bioleaching of a sulphide concentrate in a saline solution |
-
2006
- 2006-09-15 CA CA002628125A patent/CA2628125A1/en not_active Abandoned
- 2006-09-15 EP EP06851599A patent/EP1937858A2/en not_active Withdrawn
- 2006-09-15 AP AP2008004397A patent/AP2270A/en active
- 2006-09-15 AU AU2006347613A patent/AU2006347613B2/en not_active Ceased
- 2006-09-15 CN CNA2006800422079A patent/CN101341264A/en active Pending
- 2006-09-15 WO PCT/ZA2006/000108 patent/WO2008036985A2/en active Application Filing
- 2006-09-15 EA EA200800805A patent/EA013851B1/en not_active IP Right Cessation
-
2008
- 2008-03-14 US US12/048,436 patent/US20080173133A1/en not_active Abandoned
- 2008-04-09 ZA ZA200803138A patent/ZA200803138B/en unknown
Non-Patent Citations (1)
Title |
---|
None |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2014169325A1 (en) * | 2013-04-15 | 2014-10-23 | Bhp Billiton Olympic Dam Corporation Pty Ltd | Method for processing ore |
WO2018049487A1 (en) * | 2016-09-19 | 2018-03-22 | Bhp Billiton Olympic Dam Corporation Pty Ltd | Integrated hydrometallurgical and pyrometallurgical method for processing ore |
EA037379B1 (en) * | 2016-09-19 | 2021-03-22 | Биэйчпи Биллитон Олимпик Дэм Корпорейшн Рти Лтд | Integrated hydrometallurgical and pyrometallurgical method for processing ore |
Also Published As
Publication number | Publication date |
---|---|
AP2270A (en) | 2011-08-09 |
CN101341264A (en) | 2009-01-07 |
AU2006347613A1 (en) | 2008-03-27 |
AP2008004397A0 (en) | 2008-04-30 |
EA200800805A1 (en) | 2008-10-30 |
ZA200803138B (en) | 2009-08-26 |
EA013851B1 (en) | 2010-08-30 |
US20080173133A1 (en) | 2008-07-24 |
WO2008036985A3 (en) | 2008-06-26 |
EP1937858A2 (en) | 2008-07-02 |
AU2006347613B2 (en) | 2011-01-06 |
CA2628125A1 (en) | 2008-03-27 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
AU2006347613B2 (en) | Bioleaching process control | |
CA2383815C (en) | Recovery of precious metal from sulphide minerals by bioleaching | |
Miller et al. | Bacterial oxidation of refractory gold concentrates | |
CN102491546A (en) | Aeration system | |
AU773999B2 (en) | A method of operating a bioleach process with control of redox potential | |
USH2140H1 (en) | Bio-oxidation process and apparatus | |
Crundwell | Modeling, simulation, and optimization of bacterial leaching reactors | |
US8871003B2 (en) | Process for controlled oxidation of a ferrous solution | |
US20170175223A1 (en) | Bioleaching method and facility | |
CN1938437B (en) | Heap bioleaching process | |
RU2552207C1 (en) | Method of controlling process of biooxidation of sulphide concentrates | |
Hansford et al. | Oxygen transfer limitation of bio-oxidation at high solids concentration | |
US20040023350A1 (en) | Method for biological oxidation of elemental sulfur-bearing materials for sulfuric acid production | |
Harvey | Chalcopyrite Bioleaching: The Changing Face of Copper Treatment | |
CN117467852A (en) | Microorganism assisted heap leaching | |
ZA200201538B (en) | Recovery of copper from copper bearing sulphide minerals by bioleaching with controlled oxygen feed. | |
ZA200201532B (en) | Bioleaching of sulphide minerals. | |
ZA200201537B (en) | Recovery of nickel from nickel bearing sulphide minerals by bioleaching. | |
ZA200201536B (en) | Recovery of precious metal from sulphide minerals by bioleaching. | |
WO2007077290A1 (en) | Method for improving sulphidic concentrate leaching | |
ZA200707987B (en) | Reactor for the culture, biooxidation of solutions and/or large-scale propagation of isolated microorganisms and/or native micro organisms that are useful in ore leaching |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 200680042207.9 Country of ref document: CN |
|
ENP | Entry into the national phase |
Ref document number: 2628125 Country of ref document: CA |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2006347613 Country of ref document: AU |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2006851599 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 200800805 Country of ref document: EA |
|
ENP | Entry into the national phase |
Ref document number: 2006347613 Country of ref document: AU Date of ref document: 20060915 Kind code of ref document: A |