WO2000048944A1 - Improved methods for leaching of ores - Google Patents
Improved methods for leaching of ores Download PDFInfo
- Publication number
- WO2000048944A1 WO2000048944A1 PCT/US2000/004333 US0004333W WO0048944A1 WO 2000048944 A1 WO2000048944 A1 WO 2000048944A1 US 0004333 W US0004333 W US 0004333W WO 0048944 A1 WO0048944 A1 WO 0048944A1
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- WIPO (PCT)
- Prior art keywords
- alkali metal
- acid
- halide
- solubihzation
- titanium
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G23/00—Compounds of titanium
- C01G23/04—Oxides; Hydroxides
- C01G23/047—Titanium dioxide
- C01G23/053—Producing by wet processes, e.g. hydrolysing titanium salts
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- 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
- C22B11/00—Obtaining noble metals
- C22B11/06—Chloridising
-
- 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
- C22B23/0423—Halogenated 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
- C22B34/00—Obtaining refractory metals
- C22B34/10—Obtaining titanium, zirconium or hafnium
- C22B34/12—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08
- C22B34/1236—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 obtaining titanium or titanium compounds from ores or scrap by wet processes, e.g. by leaching
- C22B34/124—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 obtaining titanium or titanium compounds from ores or scrap by wet processes, e.g. by leaching using acidic solutions or liquors
- C22B34/1245—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 obtaining titanium or titanium compounds from ores or scrap by wet processes, e.g. by leaching using acidic solutions or liquors containing a halogen ion as active agent
-
- 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
- C22B34/00—Obtaining refractory metals
- C22B34/10—Obtaining titanium, zirconium or hafnium
- C22B34/12—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08
- C22B34/1236—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 obtaining titanium or titanium compounds from ores or scrap by wet processes, e.g. by leaching
- C22B34/124—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 obtaining titanium or titanium compounds from ores or scrap by wet processes, e.g. by leaching using acidic solutions or liquors
- C22B34/125—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 obtaining titanium or titanium compounds from ores or scrap by wet processes, e.g. by leaching using acidic solutions or liquors containing a sulfur ion as active agent
-
- 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
- C22B34/00—Obtaining refractory metals
- C22B34/10—Obtaining titanium, zirconium or hafnium
- C22B34/12—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08
- C22B34/1236—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 obtaining titanium or titanium compounds from ores or scrap by wet processes, e.g. by leaching
- C22B34/1259—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 obtaining titanium or titanium compounds from ores or scrap by wet processes, e.g. by leaching treatment or purification of titanium containing solutions or liquors or slurries
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- 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
- C22B34/00—Obtaining refractory metals
- C22B34/30—Obtaining chromium, molybdenum or tungsten
- C22B34/34—Obtaining molybdenum
-
- 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
- C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
- C22B7/006—Wet processes
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- 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
- Rutile (T ⁇ O 2 ) is a mineral used for many purposes. Amongst other uses, it is a source of titanium metal and a pamt pigment. Synthetic rutile is generally considered as any rutile created from another mineral, usually llmemte, that has at least 90% TiO,. High pu ⁇ ty rutile is 99.9%+ T ⁇ 0 2 . High pu ⁇ ty rutile generally carries a commercial value premium. llmemte (FeT ⁇ O 3 ) is most often converted to synthetic rutile by high temperature leaching with hydrochlo ⁇ c acid in an autoclave. Leachmg temperatures are generally between 800 to 900°C. Ferric chloride is sometimes used in these autoclave leaches to increase the reaction rates at the lower temperatures. Zoumei Jin et al (B. Mishra and G.J. Kiporous eds, In: Titanium Extraction and
- the subject invention pertains to novel and highly efficient methods for leachmg valuable minerals, such as cobalt (Co), nickel (Ni), titanium (Ti), copper (Cu), molybdenum
- One aspect of the present invention concerns methods for recove ⁇ ng titanium from ores.
- One embodiment of the subject method uses an acidic solution, such as sulfuric acid, to leach titanium oxides from a mineral feed. Additional modifications and/or steps, including, for example, g ⁇ nding of the ore, addition of an alkali metal halide, addition of a carbon source, and adjustment of pressure and/or temperature, can be incorporated in the process.
- a mineral feed is contacted with an acid and an alkali metal halide to leach titanium oxides from the feed.
- High pu ⁇ ty titanium dioxide having a commercial premium over synthetic rutile can be produced using the methods of the subject invention.
- the present invention provides a method for recovery of nickel and cobalt from a mineral feed by leachmg the feed with an acidic solution.
- a mixture of sulfuric acid and an alkali metal halide are used to leach out cobalt and nickel from a late ⁇ te ore.
- the subject methods can also be used to recover cobalt, nickel, copper, etc. by leachmg these elements from scrap metal.
- the subject invention also concerns methods for recovering multiple metals or metal oxides in separate solutions.
- ore is contacted with an acid solution, such as sulfuric acid.
- Solid residue is then collected and contacted with an alkali metal halide and acid solution.
- the subject method is used to recover copper separately from gold and silver. The copper is recovered p ⁇ ma ⁇ ly in the first acid solution, while the gold and silver are recovered in the alkali metal halide and acid solution.
- Figure 2 shows the results of four consecutive one-hour leaches of titanium and iron from llmemte.
- Figure 3 shows pulp density relationships m the leaching of titanium and iron from llmemte.
- Figure 4 shows the results of expenments evaluating the effect of an alkali metal halide
- Figure 5 shows the results of expenments evaluating the effects of grinding the ore on recovery rates.
- Figure 6 shows the results of expenments evaluating the effect of adding a carbon source during the sulfunc acid leachmg process.
- Figure 7 shows the results of expenments evaluating the effect of an alkali metal halide on the sulfu ⁇ c acid leachmg process of leachmg nickel from an initial late ⁇ te feed (Latente-1).
- Figure 8 shows the results of expenments evaluating the effect of an alkali metal halide on the sulfu ⁇ c acid leachmg process of leach g cobalt from an initial late ⁇ te feed (Late ⁇ te-1).
- Figure 9 shows the results of expenments evaluating the effect of an alkali metal halide on the sulfunc acid leach g process of leaching nickel from a second late ⁇ te feed (Latente-2).
- Figure 10 shows the results of expenments evaluating the effects of an alkali metal halide on the sulfunc acid leachmg process of leachmg cobalt from a second late ⁇ te feed
- the subject invention provides novel materials and methods useful for the recovery of minerals from ores.
- An important component of the leachmg processes of the subject invention is the use of an acidic solution.
- the acid is sulfu ⁇ c acid.
- Sulfunc acid used in the leachmg procedures can be at a concentration ranging from about 20 grams per liter to about 500 grams per liter. In a preferred embodiment, the concentration of sulfunc acid ranges from about 150 grams per liter to about 250 grams per liter. Preferably, the concentration of sulfunc acid is approximately 200 grams per liter.
- particularly preferred embodiments of the subject invention utilize additional factors including, for example, the use of an alkali metal halide, gnnding the ore, addition of a carbon source, and/or adjustment of the temperature at which the process is earned out.
- the efficiency of the leachmg process can be improved by gnndmg the ore p ⁇ or to treatment.
- the ore is ground so that it can pass through a 200 mesh sieve.
- an alkali metal salt can be added to the leach solution to improve recovery.
- the alkali metal salt can be for example, an alkali metal halide, alkali metal mt ⁇ te, alkali metal nitrate, alkali metal sulfite or alkali metal thiomte.
- the metal halide can be, for example, NaCI, KCl, NaBr or KBr, or mixtures of one or more of these.
- the metal sulfites can be, for example, sodium sulfite, sodium metabisulfite, sodium bisulfite, sodium dithionite, or other alkali metal or ammonium sulfite, metabisulfite, bisulfite or dithionite.
- a further embodiment of the subject invention involves the use of a carbon source to improve recovery.
- the carbon source can be, for example, graphite or activated carbon.
- the source of this matenal can be, for example, from coconut shell or wood.
- the present invention accordingly provides in one embodiment a method for recove ⁇ ng titanium ox ⁇ de(s) from a titanium and iron-containing mineral feed, the method including the steps of
- the titanium ox ⁇ de(s) may be titanium dioxide.
- the titamum-contammg mineral feed is typically post heavy mineral concentration products.
- the feed will include titanium mineralization. Typical examples of this titanium mineralization are llmemte (FeT ⁇ O 3 ), leucoxene, perovskite (CaT ⁇ O 3 ) and titano magnetite.
- the feed may m an alternative embodiment comp ⁇ se a bulk llmemte concentrate.
- Other titanium-containing mineral feed matenals are contemplated within the scope of the invention.
- the present invention provides in another separate embodiment a method for recove ⁇ ng synthetic rutile (T ⁇ O 2 ), from a mineral feed compnsmg llmemte (FeT ⁇ O 3 ), the method including the steps of:
- the acidic solution preferably includes sulfunc acid.
- the sulfunc acid used m the leachmg step is typically at a concentration m the range of from about 20 grams per liter to about 500 grams per liter.
- the concentration of sulfunc acid is in the range of from about 150 grams per liter to about 250 grams per liter. Most preferably the concentration of sulfunc acid is about 200 grams per liter.
- Other acids contemplated for use in step (a) of the present invention include, but are not limited to, a halide acid such as hydrochlonc acid or hydrobromic acid.
- the typical concentration of halide acid used is in the range of from about 150 to about 350 grams per liter.
- Step (a) is typically earned out in the presence of an alkali metal halide at a ratio of alkali metal halide to llmemte in the feed in the range of from about 1 : 1 to 2: 1.
- the ratio of alkali metal halide is from about 1 : 1 to 1.5: 1. More preferably, the ratio is about 1.2: 1.
- Suitable alkali metal ha des include, but are not limited to, NaCI, KCl or KBr or mixtures of one or more of these.
- the alkali metal halide can be added directly to the leach solution.
- the alkali metal halide can be combined with the feed p ⁇ or to introduction of the leachmg solution.
- the feed may be subjected to a boildown pretreatment (i e., by boiling down to approximate dryness) m the presence of the alkali metal halide whereby the feed (e.g , llmemte surfaces) are coated with alkali metal halide p ⁇ or to leachmg.
- a combination of the foregoing i.e , direct addition of alkali metal halide to the feed and combination of alkali metal halide with the feed p ⁇ or to leaching, can be used in the subject methods.
- a proportion of the alkali metal halide is combined with the feed p ⁇ or to step (a) and a proportion of the alkali metal halide is added directly to the leach solution.
- steps (a) and (b) may be conducted simultaneously or separately once solubihzation commences. It is particularly preferred to concurrently remove some of the pregnant solution from the leach residue to permit precipitation to take place away from the leach residue.
- the precipitation step (b) can be regulated by adjustment of temperature and/or pH of the solution.
- step (a) is earned out at a temperature in the range of from about 80°C to about 120°C and, preferably, is in the range of from about 90°C to about 110°C.
- the operating temperature for step (a) is about 100°C.
- the leach solution m step (a) has a solids content of up to about 60% by weight.
- the leach solution has a solids content of from about 10% to about 40%.
- the feed may be ground mto finer particles.
- the feed may be subjected to fine g ⁇ ndmg.
- the majority of particles in the feed are capable of passing through a 75 micron sieve after g ⁇ ndmg.
- a source of carbon may be provided m the subject method.
- the carbon may be in the form of any commercially available carbon source including, for example, activated carbon, coal, coke, charcoal or graphite.
- a preferred source of carbon is activated carbon derived from coconut shell.
- the ratio of carbon to feed (e g., llmemte) is typically between about 0.01:1 to 1 : 1.
- Methods according to the present invention may be earned out at or above atmospheric pressure.
- the typical elevated pressures and temperatures at which the present methods may be performed are in the range of from about 1 bar to about 30 bar.
- pressures are in the range of from about 1 bar to about 5 bar.
- Temperatures used in the subject methods range from about 100°C to about 235°C.
- temperatures range from about 100°C to about 150°C.
- the leach residue produced from step (a) can be subjected to further leaching to solubilize undissolved iron and or titanium in the residue.
- the further leachmg can be performed using fresh acidic solution.
- spent leach liquor or a combination of fresh acidic solution and spent leach liquor can be used.
- step (a) of the subject method can be performed in the presence of ferrous and/or feme ions to promote dissolution of the iron mineralization.
- Ferrous ions will generally be present in recirculated process plant solutions
- iron may be removed from the leachant solution using standard techniques, such as precipitation.
- the purpose is to remove soluble iron from any process solutions.
- Solvent extraction, ion exchange, reverse osmosis or other techniques can also be used to remove soluble iron.
- the leach time for this embodiment is generally relatively long, and typically is in the range of from about 50 to about 120 hours. Preferably, leach time is from about 60 to about 100 hours.
- the operating conditions are much milder than conventional autoclave techniques, leading to large capital and operating cost advantages. Sulfu ⁇ c acid and alkali metal halides are easier to handle than the hydrochloric acid used m the Zoumei Jm et al. process refe ⁇ ed to above.
- the present invention provides m another separate embodiment, a method for recovenng titanium from a titanium and iron-containing mineral feed, the method including the steps of (a) solubihzmg titanium and iron by leachmg the feed with an acidic solution in the presence of an alkali metal halide and a source of activated carbon;
- the present invention provides in another separate embodiment a method for recove ⁇ ng titanium from a mineral feed comp ⁇ smg llmemte (FeT ⁇ O 3 ), the method including the steps of
- the present invention provides m another separate embodiment a method for recovenng titanium ox ⁇ de(s) from a mineral feed comprising llmemte (FeT ⁇ O 3 ), the method including the steps of : (a) leachmg the llmemte with an acidic solution at a temperature m the range of from about 80 to 120°C m the presence of an alkali metal halide for a predetermined time, the leach solution containing up to about 60% by weight solids to produce a leachant solution containing iron and titanium ions; (b) separating the iron from the titanium in the leachant solution; and (c) recovering the separated titanium as T ⁇ 0 2 .
- reaction time of step (a) of this embodiment is up to about an hour.
- reaction time of step (a) is up to about half an hour. More preferably, the reaction time is m the range of from about 5 to about
- step (a) above may be repeated to solubilize unleached titanium in the residue obtained following step (a) in order to obtain cumulative maximum solubility of titanium.
- Fresh acidic solution and alkali metal halide can be used when step (a) is repeated.
- Step (a) may m one embodiment comprise a type of countercurrent leach circuit.
- the acidic solution in this embodiment can be supplemented with hydrochlonc acid in one or more steps of a repeated leach sequence to assist m enhancing the titanium solubility profile.
- the present invention provides a method for recove ⁇ ng titanium from a titanium and iron-containmg mineral feed, the method including the steps of:
- the halide acid used in step (a) can be, for example, hydrochloric acid or hydrobromic acid.
- concentration of halide acid used can be in the range of from about 150 to about 350 grams per liter acid.
- Any precipitated titanium reporting to the leach residue of this embodiment may be recovered m subsequent leachmg operations.
- the present invention provides m another separate embodiment a method for recove ⁇ ng titanium from a feed comp ⁇ smg finely ground llmemte (FeT ⁇ 0 3 ), the method including the steps of
- step (b) repeating step (a); (c) separating at least some of the pregnant solution from the leach residue;
- the present invention provides multistage leaching of iron and titanium from an iron and titamum-bearmg mineral feed, the method comp ⁇ sing the following steps. (a) contacting the feed mate ⁇ al with an acid — alkali halide solution for a penod of time sufficient to solubilize the titanium but not so long as to allow the titanium to appreciably precipitate;
- step (b) separating the pulp from the leach liquor; (c) contacting the pulp with fresh leach liquor and repeating steps (a) and (b) until all economically feasible titanium is leached; and (d) selectively recove ⁇ ng the titanium and iron m separate stages from the leach solutions by precipitation, solvent extraction or other means.
- the conditions of step (a) can involve percent solids on a weight/weight basis of between about 1 percent and about 60 percent.
- the typical percent solids are in the range of from about 10% to 40%
- the solids may be ground to fine size to facilitate leachmg, typically so that the feed passes a 73 micron sieve
- the acid used is most typically sulfunc acid.
- the acid concentration can range from about 20 to about 300 grams per liter acid. Most typically the acid concentration ranges from about 150 to 230 gram per liter.
- the alkali halide can be any alkali halide.
- the alkali halide is NaCI, KCl,
- the concentration of alkali halide can range from about 50 grams per liter to about 400 grams per liter. Preferably, the alkali halide concentration is about 100 to about 200 grams per liter.
- the leaching is most typically carried out at about room pressure
- the temperature can be between about 40°C and about 110°C at room pressure
- leachmg temperature is between about 90 °C and about 105°C.
- Leaching at room pressure will typically be performed m a leach vessel with a condenser to limit the loss of halide acid generated m the leach solution
- the titanium is allowed to reach a concentration as high as possible before it begins to re- precipitate onto the leach feed matenal. This is typically slightly over four (4) grams of titanium per liter of solution.
- the leach time to accomplish this solubihzation will depend on the va ⁇ ous aforementioned parameters but will usually range from about 10 minutes to 1 hour
- the method of solid — liquid separation in step (b) can be any method that makes a good separation of the solids from the leach liquor in a relatively short time. These include methods such as cyclones, filters, centnfuges, magnetic separators, and settlers. The list is not meant to exclude any unnamed method.
- the fresh leach liquor in step (c) can be leach liquor from which the titanium content has been reduced or eliminated.
- the iron content of liquor should be controlled so that no precipitation of an iron compound occurs dunng the leachmg
- the titanium can be totally or partially removed from the leach liquor in step (d) by the method that makes the most economic sense for any given plant.
- the methodology available includes, but is not limited to, precipitation by seeding or pH adjustment, crystallization, solvent extraction, and ion exchange.
- the iron can be removed in a similar fashion in a step before or after the titanium recovery. Titanium and iron are recovered as separate products, in separate stages. The titanium would be recovered as a titanium salt, most typically T ⁇ O 2 . The iron would most typically be recovered as an iron salt such as ferrous chlo ⁇ de or sulphate.
- the present invention also concerns methods for the recovery of other minerals, such as nickel, cobalt, copper, molybdenum, lead, zmc, gold or silver from ore, soil, concentrate, slag or residue.
- other minerals such as nickel, cobalt, copper, molybdenum, lead, zmc, gold or silver from ore, soil, concentrate, slag or residue.
- a method is provided for the dissolution of nickel and cobalt from a nickel, cobalt and iron-containing mineral feed, the method compnsmg solubihzmg the nickel, cobalt and iron m the feed by leachmg the feed with an acidic solution.
- an alkali metal salt can be added to the leach solution to improve recovery.
- the alkali metal salt can be for example, an alkali metal halide, alkali metal nit ⁇ te, alkali metal nitrate, alkali metal sulfite or alkali metal thiomte.
- the metal halide can be, for example, NaCI, KCl, NaBr or KBr, or mixtures of one or more of these.
- the metal sulfites can be, for example, sodium sulfite, sodium metabisulfite, sodium bisulfite, sodium dithionite, or other alkali metal or ammonium sulfite, metabisulfite, bisulfite or dithionite.
- the method of the invention can be conducted at above ambient temperatures and at or above atmospheric pressures prior to metal extraction by precipitation, solvent extraction or other means
- the nickel and cobalt-contammg mineral feed is typically post beneficiation by comminution and thickening products.
- a typical example of nickel and cobalt mineralization is a latente ore.
- the feed may compnse a bulk latente concentrate.
- One embodiment of the present method provides for recovering nickel and cobalt from a mineral feed comprising late ⁇ te, the method including the step of solubihzmg nickel and cobalt and iron in the late ⁇ te by leachmg the latente with an acidic solution in the presence of an alkali metal halide at a temperature not exceeding about 150°C at normal pressures prior to nickel and cobalt extraction by established precipitation, solvent extraction or other means.
- the acidic solution contains sulfuric acid.
- the sulfuric acid used in the leachmg step is typically at a concentration in the range of from about 20 grams per liter to about 500 grams per liter.
- the concentration of sulfu ⁇ c acid is in the range of from about 150 grams per liter to about 250 grams per liter.
- the concentration of sulfunc acid is about 200 grams per liter.
- Other acids contemplated for use in the present invention include halide acids, for example, hydrochlonc acid or hydrobromic acid.
- the typical concentration of halide acid used is in the range from about 50 to about 350 grams per liter acid.
- the process is typically earned out m the presence of an alkali metal halide at a ratio of alkali metal halide to late ⁇ te in the feed m the range of from about 0.05:1 to about 4:1.
- the ratio is about 0J : 1 , and most preferably about 0.2: 1.
- the alkali metal salt may be added directly to the leach solution.
- the alkali metal salt is combined with the feed p ⁇ or to introduction of the leachmg solution.
- the feed may be subjected to a boildown pre-treatment (i.e., by boiling down to approximate dryness) in the presence of the alkali metal salt whereby the feed (e g , latente) surfaces are coated with alkali metal salt p ⁇ or to leachmg.
- the solution of alkali salt may be sprayed on a heap of latentic ore and allowed to evaporate.
- a proportion of the alkali metal salt is combined with the feed p ⁇ or to solubihzation and a proportion of the alkali metal salt is added directly to the leach solution. It is particularly preferred to concurrently remove some of the pregnant solution from the leach residue to permit separation of the nickel and cobalt to take place away from the leach residue.
- the process is carried out at a temperature in the range of from about 80 °C to about 120°C.
- the temperature is m the range of from about 90 °C to about 110°C
- a typical operating temperature for the process is about 100°C.
- the leach solution in the subject process preferably has a solids content of up to about 60% by weight.
- the leach solution has a solids content of from about 10 to 40%.
- the feed can be ground into smaller particles. It is preferred that the feed be subjected to fine gnndmg.
- the majority of particles in the feed are capable of passing through 75 micron sieve. Typically, at least 75% of the particles m the feed are of a size that can pass through 75 micron sieve openings.
- Methods according to the present invention may be earned out at or above atmosphenc pressure.
- the typical elevated pressures and temperatures at which methods according to the invention may be performed are in the range of from about 1 bar to about 30 bar.
- pressures are m the range of from about 1 bar to about 5 bar and temperatures range from about 100°C to about 235 °C.
- m the range of from about 100°C to about 150°C.
- the leach residue produced by the present process may be subjected to further leachmg to solubilize undissolved iron and/or nickel and cobalt m the residue.
- the further leachmg can be performed using fresh acidic solution.
- spent leach liquor, or a combination of fresh acidic solution and spent leach liquor may be used in the process.
- the process may be performed m the presence of ferrous and/or feme ions to promote dissolution of the iron mineralization.
- Ferrous ions will generally be present in recirculated process plant solutions.
- a typical reaction time for the process of this embodiment is up to about six hours.
- the reaction time is up to about two hours. More preferably, the reaction time is in the range of from about 15 minutes to about 3 hours. It has been observed that nickel and cobalt solubility reaches a peak dunng reaction times of approximately that length.
- a person of ordinary skill in the art can vary leach time so as to leach less of an unwanted species such as manganese or iron at the expense of some cobalt and nickel recovery.
- the process above may be repeated to solubilize unleached nickel or cobalt m the residue m order to obtain cumulative maximum solubility of nickel and cobalt.
- Fresh acidic solution and alkali metal halide may be used when the process is repeated.
- the process may in one embodiment comprise a type of countercurrent leach circuit.
- the acidic solution may in this embodiment be supplemented with hydrochloric acid in one or more steps of a repeated leach sequence to assist in enhancing the nickel or cobalt solubility profile.
- a metal halide salt may be used either to precondition an aqueous slurry or it may be sprayed onto the feed material and allowed to evaporate prior to contacting with sulfunc acid.
- This flash leachmg process utilizes the selective nature of the leach to achieve a cobalt nch solution containing only minor amounts of nickel, manganese, iron, etc.
- super alloy scrap and other recycled metal alloys may be leached by treating with a halide salt of the metal and sulfunc acid.
- concentrations of the metal halide salt and the sulfunc acid will be dependent upon the specific scrap mixture.
- This embodiment can be utilized to selectively leach specific metals or to place all the metals into solution.
- This embodiment may also be used to solubilize radio-nucleosides of such metal as nickel from a radiated scrap. Oxygen or other oxidizing gasses such as chlo ⁇ ne can be added to the system to oxidize the metal.
- the alkali metal halide may be substituted with a sulfur-based reducing chemical.
- a sulfur-based reducing chemical For example, sodium sulfite, sodium metabisulfite, sodium bisulfite, sodium dithionite, or other alkali metal or ammonium sulfite, metabisulfite. bisulfite or dithionite can be used in place of the alkali metal halide.
- sulfur based reducing chemicals will facilitate the reduction of the transition metal, opening the ore up to attack by the sulfu ⁇ c acid. The metal of economic interest need not always be the one reduced.
- Alkali metal nitrates or nitntes may be used with sulfunc acid to leach most metals. These techniques may be used to leach metals from sulfide minerals or from scrap, residue, slags, concentrates, or soils.
- the process utilizing a metal halide salt and sulfunc acid may be used, with minor modifications, in currently existing counter current decantation (CCD) circuits. Such an embodiment would utilize fresh feed matenal to achieve neutralization to a pH adequate to retain iron in solution.
- CCD counter current decantation
- the resultant leach liquor may be further neutralized to precipitate iron as a hydroxide m the presence of a binding material. The iron precipitate may then be partially dned and pelletised to produce pig iron feed stocks.
- the method of solid-liquid separation can be any method that produces a good separation of the solids from the leach liquor in a relatively short time. These include, but are not limited to, methods such as cyclones, filters, centrifuges, magnetic separators, and settlers.
- the nickel or cobalt can be totally or partially removed from the leach liquor by the method that makes the most economic sense for any given plant.
- the methodology available includes, but is not limited to, precipitation by seeding or pH adjustment, crystallization, solvent extraction, and ion exchange.
- the subject invention also concerns methods for recovering multiple metal or metal oxides in separate solutions.
- Mineral species of economic value are often associated with species that consume the chemical reagents that are used to leach them. Sometimes even though the consuming species is of economic value, the overall leach becomes uneconomic. The most common example of this is copper-gold ores. Following are examples which illustrate procedures for practicing the invention. These examples should not be construed as limiting. All percentages are by weight and all solvent mixture proportions are by volume unless otherwise noted.
- the Ti appears to be leached withm one hour.
- a 100 gram quantity of llmemte with a head assay of 34.0%> Fe and 27.0% Ti, and particle size such that 100% of the particles pass through a 75 micron screen was leached for 72 hours at 100° C m 1 liter of 200 gram per liter H 2 SO 4 — 120 gram per liter alkali metal halide solution.
- a 100 gram quantity of activated carbon was also present in the leach solution.
- the leach liquor was monitored periodically for Ti and Fe content. The results of the experiment are shown in Table 1. Titanium is dissolved then observed to subsequently precipitate.
- Example 2 Using the data in Example 1 allowed the development of a new leach procedure for llmemte.
- the procedure comp ⁇ ses leachmg llmemte for one hour or less and then contacting it with fresh leach solution. In this manner both the iron and titanium is leached together. This was tested using the same conditions as m the 96-hour test. The results of four (4) consecutive one-hour leaches on the same ore sample are shown m Figure 2. As can be seen, approximately the same amount of iron and llmemte was leached in each step.
- the ordinarily skilled artisan having the benefit of the teachings desc ⁇ bed herein, can determine the proper reagent concentration, temperature, particle size of the ore, whether to include carbon and its form (e.g., activated carbon or graphite), or atmosphenc pressure (typically ⁇ 3 atmospheres) that is optimum for a particular ore.
- the technique of separating the Ti as T ⁇ 0 2 with short leach times followed by precipitation of T ⁇ O 2 is also applicable to other leach systems such as the hydrochlonc acid leach system.
- Experiment A comprises a leach solution of 60 grams alkali metal halide, 100 grams H 2 ,SO 4 , and 350 grams of H 2 O heated to 100 C C m Erlenmeyer flasks on a stir ⁇ ng hotplate to which is added 50 grams of minus 75 microns particle size llmemte resulting m a 9% pulp density.
- Experiment B comprises a leach solution of 60 grams alkali metal halide, 100 grams H 2 S0 4 , and 350 grams of H 2 0 heated to 100°C in Erlenmeyer flasks on a stir ⁇ ng hotplate to which is added 100 grams of minus 75 microns particle size ilmemte resulting m a 16% pulp density.
- the ilmemte had an assay head of 30% titanium and 34% iron.
- the following procedure steps are applied separately to Expe ⁇ ment A and Expe ⁇ ment B:
- Step 1 A condenser is placed on the Erlenmeyer containing the slurry compnsmg the presc ⁇ bed solution and ilmemte feed; Step 2. The slurry is stirred vigorously with a magnetic stirrer for 30 minutes with the temperature maintained at 100°C; Step 3. The Erlenmeyer and contents are cooled for a couple of minutes in a room temperature water bath; Step 4. The Erlenmeyer solution is decanted into a cent ⁇ fuge rube and centrifuged at 4,000 rpm for 5 minutes; Step 5. The liquor in the ccntnfugc tube is decanted and separated from the solids into a sample bottle, volume and weight determined and retained for further test work including analysis; Step 6.
- Step 8 The procedure is continued by repeating Steps 1 through 7 inclusive, a total of seven times and thus equating to a total leach duration of 4 hours; Step 9.
- the post cent ⁇ fugmg liquors collected at each repetition of Step 5 are individually subsampled and analysed for titanium and iron;
- Step 10 Calculations are conducted to determine titanium and iron contents of both solids and liquors and comparisons made with the respective elemental assay values of the ilmemte ore feed;
- Step 11 The individual liquors remaining after the subsamplmg conducted in Step 9 are combined in a flask and subsampled and analysed for titanium and iron; Step 12.
- the titanium can be totally or partially removed from the leach liquor by the method that makes the most economic sense for any given plant.
- the methodologies available include, but are not limited to, precipitation by seeding or pH adjustment, crystallization, solvent extraction, and ion exchange.
- Example 3 Effect of Alkali Metal Halide
- the salt which was used was NaCI at 0%, 5%, 15% and 25%
- Example 4 Effect of Gnndmg of Ore
- grinding of the ore can be used to increase the reaction rate of leaching iron from ilmenite. This is shown in Figure 5 and Table 4. Both tests were performed using a 100 gram quantity of ilmenite placed in one liter of 200 grams per liter sulfuric acid and 150 grams per liter alkali metal halide solution heated to 100°C. The experiments were conducted on two samples of the same ilmenite feed. One experiment used course ilmenite (100% retained on a 75 micron screen) and the other experiment used fine ilmenite (100% passing through a 75 micron screen). The slurry was vigorously stirred for 72 hours and the iron concentration periodically monitored. The ground ore (finer particle sized samples) had faster early and late leach kinetics than the unground ore (coarser particle sized sample). The kinetics of the ore during the 5 to 25 hour time period was similar in both cases.
- Example 6 Leachmg of Copper and Nickel from Latente Ore with a Sulfuric Acid-Hahde- Carbon System
- This ore has an assay head of 2.36% Co, 1.26% Ni, 11.00% Fe, 10.80% Mn.
- a sample of 100 grams of ground, -200 mesh ore was first treated with 200 grams of NaCI dissolved in 650 grams of water The water was evaporated on a hot plate. This procedure is a speeded up simulation of spaymg a heap of ore with a salt solution and letting it evaporate naturally. The ore-salt solids were then slur ⁇ ed in 200 grams of sulfu ⁇ c acid in 700 grams of water solution. The stirred slurry was brought to 100° C on a stirnng hot plate, and then 100 grams of +65 mesh, coconut shell, activated carbon was added.
- Example 7 Effect of Alkali Metal Halide on the Leachmg of Nickel and Cobalt from Latente 1 Expenments were conducted on two samples of 100 grams of late ⁇ te- 1 feed, compnsing
- Step 1 A condenser is placed on the Erlenmeyer containing the slurry comp ⁇ sing the prescnbed solution and late ⁇ te feed;
- Step 2 The slurry is stirred vigorously with a magnetic stirrer for the duration of the test with the temperature maintained at 100°C; Step 3.
- the test is sampled at predetermined times, eg., 15 minutes, 30 minutes, etc., by pipetting 10 ml of the hot slurry from the Erlenmeyer into a centnfuge tube and centrifuge at 4,000 ⁇ m for 5 minutes;
- Step 4 The centnfuged timed leach solution is transferred mto a sample tube for later analysis; Step 5. 10 ml of make-up leach solution is used to wash the centnfuged residue back into the Erlenmeyer, while the Erlenmeyer continues to be agitated at 100°C on the hot plate; Step 6. At the end of the test (e.g. , 6 hours) the contents of the Erlenmeyer is poured into two centnfuge tubes, using an additional very small amount of distilled water to wash out any residue remaining on the mside lip of the Erlenmeyer, and then centrifuged; Step 7.
- centnfuged liquid contents from both centnfuge tubes is decanted into a graduated cylinder and allow to cool; Step 8. Then having read the volume of PLS solution, approximately 20 ml is transferred into a sample tube and analysed for nickel and cobalt; Step 9. Calculations are conducted to determine nickel and cobalt contents of the liquors and compa ⁇ sons made with the respective elemental assay values of the late ⁇ te ore feed; Step 10. Nickel and cobalt can be totally or partially removed from the leach liquor by the method that makes the most economic sense for any given plant.
- the methodologies available va ⁇ ously include, but are not limited to, precipitation of metallic salts by seeding, pH adjustment, or crystallisation; solvent extraction and electrowmnmg of elemental metal; and ion exchange.
- This example shows the leachmg of silver from a copper refinery pilot plant's slimes
- the test was conducted at 100°C with 200 gram per liter sulfu ⁇ c acid and 200 gram per liter NaCI. Samples of 50 grams of slimes were leached in 500 miUiliters of solution. The leachmg was conducted for 48 hours. The results are shown m the Table 9.
- Example 11 Two Stage Leaching of Different Metals into Two Separate Leach Liquors An oxide copper ore sample, ground to minus 200 mesh, with a head grade of 0.91%>
- a person skilled in the art, having the benefit of the teachings of this disclosure, can adjust the acid concentration and temperature to achieve complete recovery of the copper in the first stage while maintaining excellent recovery of the Au and Ag in the second stage.
- the subject method can also be readily adapted to heap leaching.
Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA 2363031 CA2363031C (en) | 1999-02-19 | 2000-02-18 | Improved methods for leaching of ores |
BR0008962A BR0008962A (en) | 1999-02-19 | 2000-02-18 | Improved methods for ore leaching |
APAP/P/2001/002267A AP1870A (en) | 1999-02-19 | 2000-02-18 | Improved methods for leaching of ores |
AU33705/00A AU3370500A (en) | 1999-02-19 | 2000-02-18 | Improved methods for leaching of ores |
Applications Claiming Priority (6)
Application Number | Priority Date | Filing Date | Title |
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US12082099P | 1999-02-19 | 1999-02-19 | |
US60/120,820 | 1999-02-19 | ||
AUPQ2706 | 1999-09-08 | ||
AUPQ2706A AUPQ270699A0 (en) | 1999-09-08 | 1999-09-08 | Improvements in or relating to methods for leaching titanium ores |
AUPQ4144 | 1999-11-18 | ||
AUPQ4144A AUPQ414499A0 (en) | 1999-11-18 | 1999-11-18 | Improvements in orrelating to methods for leaching nickel and cobalt ores |
Publications (1)
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WO2000048944A1 true WO2000048944A1 (en) | 2000-08-24 |
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PCT/US2000/004333 WO2000048944A1 (en) | 1999-02-19 | 2000-02-18 | Improved methods for leaching of ores |
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AP (1) | AP1870A (en) |
BR (1) | BR0008962A (en) |
CA (1) | CA2363031C (en) |
MY (1) | MY121143A (en) |
OA (1) | OA11837A (en) |
WO (1) | WO2000048944A1 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2004031422A1 (en) * | 2002-10-01 | 2004-04-15 | European Nickel Plc | Heap leaching base metals from oxide ores |
WO2005090619A1 (en) * | 2004-03-18 | 2005-09-29 | Bhp Billiton Innovation Pty Ltd | Production of titania |
AU2003271879B2 (en) * | 2002-10-01 | 2008-01-10 | European Nickel Plc | Heap leaching base metals from oxide ores |
CN105016748A (en) * | 2015-07-04 | 2015-11-04 | 张燕 | Vanadium iron slag-gangue fireproof pouring material |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1761765A (en) * | 2003-11-19 | 2006-04-19 | 方法研究奥特克公司 | Process for the recovery of titanium in mixed chloride media |
EA020950B1 (en) | 2007-09-17 | 2015-03-31 | Баррик Гольд Корпорейшн | Method to improve recovery of gold from double refractory gold ores |
US8262770B2 (en) | 2007-09-18 | 2012-09-11 | Barrick Gold Corporation | Process for controlling acid in sulfide pressure oxidation processes |
AU2008300273B2 (en) | 2007-09-18 | 2012-03-22 | Barrick Gold Corporation | Process for recovering gold and silver from refractory ores |
ES2774385T3 (en) | 2014-07-08 | 2020-07-20 | Avertana Ltd | Extraction of products from minerals containing titanium |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB409847A (en) * | 1933-01-18 | 1934-05-10 | Peter Spence & Sons Ltd | Improvements in and relating to the preparation of titanium and iron compounds |
US3091515A (en) * | 1961-09-14 | 1963-05-28 | Nat Lead Co | Method for producing titanium dioxide pigments |
US3218131A (en) * | 1961-01-27 | 1965-11-16 | Independence Foundation | Process for recovery of titania values |
US4552730A (en) * | 1984-08-27 | 1985-11-12 | The United States Of America As Represented By The Secretary Of The Interior | Recovery of titanium from perovskite using sulfuric acid leaching |
EP0186370A2 (en) * | 1984-12-10 | 1986-07-02 | Grampian Mining Company Limited | Titanium dioxide pigment production from ilmenite |
EP0547744A1 (en) * | 1991-10-09 | 1993-06-23 | PACIFIC METALS Co., Ltd. | Process for recovering metal from oxide ores |
WO1995024510A1 (en) * | 1994-03-08 | 1995-09-14 | Rgc Mineral Sands Limited | Leaching of titaniferous materials |
WO1996024555A1 (en) * | 1995-02-10 | 1996-08-15 | Bhp Minerals International Inc. | PROCESSING ILMENITE ORE TO TiO2 PIGMENT |
-
2000
- 2000-02-18 BR BR0008962A patent/BR0008962A/en not_active Application Discontinuation
- 2000-02-18 AP APAP/P/2001/002267A patent/AP1870A/en active
- 2000-02-18 CA CA 2363031 patent/CA2363031C/en not_active Expired - Fee Related
- 2000-02-18 OA OA1200100218A patent/OA11837A/en unknown
- 2000-02-18 WO PCT/US2000/004333 patent/WO2000048944A1/en active Application Filing
- 2000-02-21 MY MYPI20000632 patent/MY121143A/en unknown
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB409847A (en) * | 1933-01-18 | 1934-05-10 | Peter Spence & Sons Ltd | Improvements in and relating to the preparation of titanium and iron compounds |
US3218131A (en) * | 1961-01-27 | 1965-11-16 | Independence Foundation | Process for recovery of titania values |
US3091515A (en) * | 1961-09-14 | 1963-05-28 | Nat Lead Co | Method for producing titanium dioxide pigments |
US4552730A (en) * | 1984-08-27 | 1985-11-12 | The United States Of America As Represented By The Secretary Of The Interior | Recovery of titanium from perovskite using sulfuric acid leaching |
EP0186370A2 (en) * | 1984-12-10 | 1986-07-02 | Grampian Mining Company Limited | Titanium dioxide pigment production from ilmenite |
EP0547744A1 (en) * | 1991-10-09 | 1993-06-23 | PACIFIC METALS Co., Ltd. | Process for recovering metal from oxide ores |
WO1995024510A1 (en) * | 1994-03-08 | 1995-09-14 | Rgc Mineral Sands Limited | Leaching of titaniferous materials |
WO1996024555A1 (en) * | 1995-02-10 | 1996-08-15 | Bhp Minerals International Inc. | PROCESSING ILMENITE ORE TO TiO2 PIGMENT |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2004031422A1 (en) * | 2002-10-01 | 2004-04-15 | European Nickel Plc | Heap leaching base metals from oxide ores |
AU2003271879B2 (en) * | 2002-10-01 | 2008-01-10 | European Nickel Plc | Heap leaching base metals from oxide ores |
WO2005090619A1 (en) * | 2004-03-18 | 2005-09-29 | Bhp Billiton Innovation Pty Ltd | Production of titania |
EA010600B1 (en) * | 2004-03-18 | 2008-10-30 | БиЭйчПи БИЛЛИТОН ИННОВЕЙШН ПТИ ЛТД. | Production of titania |
CN105016748A (en) * | 2015-07-04 | 2015-11-04 | 张燕 | Vanadium iron slag-gangue fireproof pouring material |
Also Published As
Publication number | Publication date |
---|---|
AP1870A (en) | 2008-07-25 |
AP2001002267A0 (en) | 2001-09-30 |
BR0008962A (en) | 2001-11-27 |
OA11837A (en) | 2005-08-22 |
CA2363031C (en) | 2006-07-04 |
MY121143A (en) | 2005-12-30 |
CA2363031A1 (en) | 2000-08-24 |
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