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
  • C22B3/04—Extraction of metal compounds from ores or concentrates by wet processes by leaching
  • C22B3/06—Extraction of metal compounds from ores or concentrates by wet processes by leaching in inorganic acid solutions, e.g. with acids generated in situ; in inorganic salt solutions other than ammonium salt solutions
  • C22B3/08—Sulfuric acid, other sulfurated acids or salts thereof
• • 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
  • C22B23/00—Obtaining nickel or cobalt
  • C22B23/04—Obtaining nickel or cobalt by wet processes
  • C22B23/0407—Leaching processes
  • C22B23/0415—Leaching processes with acids or salt solutions except ammonium salts solutions
  • C22B23/043—Sulfurated acids or salts thereof
• • 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
  • C22B26/00—Obtaining alkali, alkaline earth metals or magnesium
  • C22B26/20—Obtaining alkaline earth metals or magnesium
  • C22B26/22—Obtaining magnesium
• • 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

• the present invention relates to a method and a system for recovery of nickel and cobalt from laterites. More specifically, the present invention is concerned with a method and a system for recovery of nickel and cobalt from laterites by sonic assisted sulfatation.
• Laterites can be defined as a variety of sub-soil, much weathered in tropical or subtropical climates, and containing iron oxides, alumina, silicates and, in some instances, small amounts, in percent range, of nickel along with traces of cobalt. Weathering over ages of this type of materials has created a segregation of metallic content, high concentration of iron under the form of limonite being found near the surface, while an intermediate layer, i.e. saprolite, is found located on top of the original bed rock. Nickel and cobalt distribution can vary very significantly between these three levels.
• the Caron method involves the roasting of the laterites under reducing conditions followed by leaching of Ni/Co with ammonia. This method, typically used in Cuba, Australia and Brazil, is characterized by a very high energy consumption, in particular due to the need of drying of laterite and of reduction, and yields modest recovery, typically 75-85% for nickel and 45-55% for cobalt.
• the pressure acid leaching (PAL) method incorporates some variable alternatives but essentially consists in a digestion of the laterite with sulfuric acid in an autoclave at 250° C. under 5 to 10 times the atmospheric pressure.
• This method is currently planned or used in several countries, such as Brazil, Madagascar, Australia, New Caledonia and Cuba for example.
• This method leads to higher recoveries of nickel and cobalt than the Caron method, with recovery rates above 90%.
• operation of the method can be rendered very difficult or even impossible if the starting ore is rich in magnesium or free silica. Scaling problems in the autoclave result from the presence of these substances that are of frequent occurrence in laterites.
• the PAL method for Ni/Co extraction from laterites is very capital expensive because of the high cost incurred by material requirements, especially autoclave inert to sulfuric acid at high temperatures.
• sulfuric acid is the desirable reagent for leaching nickel and cobalt from laterite but it is also obvious that the use of this reagent calls for relatively expensive equipment.
• Equally limitative is the adverse effect of the presence of magnesium and free silica in the laterites, a situation that precludes the use of laterites with high magnesium/silica content but otherwise rich in nickel and cobalt.
• a method for recovering metallic values from laterites comprising slurrying the laterites in sulfuric acid; submitting the slurry to sonication; and filtering the slurry.
• a laterite was slurried at the level of 40-50 weight % solid in a sulfuric acid solution 25 weight %, and submitted to sonication, at room temperature and under atmospheric pressure, over a period of 30 minutes. As a result of this sonication, the temperature of the slurry was raised from ambient temperature to about 70° C. After this treatment, the slurry was filtered and an elemental analysis indicated an extraction of 96% of the nickel, 88% of the cobalt, 81% of the iron and 57% of the magnesium, as sulfates of these metals.
• the reaction mass was filtered and the analysis of the filtrate showed an extraction of 96% of the nickel, 88% of the cobalt, 81% of the iron and 57% of the magnesium, as sulfates.
• the initial temperature of the slurry i.e. room temperature, i.e. about 25° C.
• room temperature i.e. about 25° C.
• an acid concentration in the range between about 10 and about 95 weight % of sulfuric acid for example between about 25 and about 50 weight % of sulfuric acid, for example between about 10 and about 40 weight % of sulfuric acid
• sonication at frequencies in the range between about 10 and about 50 kHz, for example between 20 and 30 kHz applied for a duration in the range between about 5 and about 60 minutes, extracting metallic values from the slurried laterites is thus achieved, the temperature of the slurry experiencing an increase from about 20° C., i.e. room temperature, to about 70° C. as a result the sonication.
• a method for the recovery of nickel and cobalt from laterites comprising leaching the nickel and cobalt with sulfuric acid with the assistance of ultrasonic treatment.
• the laterites can present a magnesium content up to 20%.
• the sulfuric acid can be diluted to between 10 and 40 weight %.
• the leaching is conducted at atmospheric pressure and at ambient temperature.
• the present method allows leaching of nickel and cobalt from the laterite with sulfuric acid without limitations resulting from high pressure and high temperature requirements, and without restrictions imposed on the selection of the laterites by the need to avoid high magnesium and free silica content as it is presently the case with the PAL method.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Metallurgy (AREA)
• Mechanical Engineering (AREA)
• Materials Engineering (AREA)
• Geology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Environmental & Geological Engineering (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Inorganic Chemistry (AREA)
• Manufacture And Refinement Of Metals (AREA)
• Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
• Processing Of Solid Wastes (AREA)

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Publications (1)

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Citations (6)

• 2014
  • 2014-06-13 CA CA2854393A patent/CA2854393A1/en not_active Abandoned
  • 2014-06-18 PH PH12014000166A patent/PH12014000166A1/en unknown
  • 2014-06-18 AU AU2014203320A patent/AU2014203320A1/en not_active Abandoned
  • 2014-06-27 US US14/318,150 patent/US20150267275A1/en not_active Abandoned
  • 2014-07-02 DO DO2014000155A patent/DOP2014000155A/es unknown
  • 2014-08-05 CU CUP2014000099A patent/CU20140099A7/es unknown

Patent Citations (6)

Non-Patent Citations (2)

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