WO1993018191A1 - Lixiviation en continu par evaporation inter-phases de minerais-titaniferes traites - Google Patents

Lixiviation en continu par evaporation inter-phases de minerais-titaniferes traites Download PDF

Info

Publication number
WO1993018191A1
WO1993018191A1 PCT/AU1993/000095 AU9300095W WO9318191A1 WO 1993018191 A1 WO1993018191 A1 WO 1993018191A1 AU 9300095 W AU9300095 W AU 9300095W WO 9318191 A1 WO9318191 A1 WO 9318191A1
Authority
WO
WIPO (PCT)
Prior art keywords
acid
leach
evaporators
leaching
interstage
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/AU1993/000095
Other languages
English (en)
Inventor
Edgar George Newman
Graham Francis Balderson
Charles Alexander Macdonald
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
PIVOT MINING NL
Original Assignee
PIVOT MINING NL
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by PIVOT MINING NL filed Critical PIVOT MINING NL
Priority to AU36236/93A priority Critical patent/AU3623693A/en
Publication of WO1993018191A1 publication Critical patent/WO1993018191A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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
    • 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

Definitions

  • THIS INVENTION relates to the continuous leaching of treated titaniferous ores with inter-stage evaporation.
  • the invention forms a part of a process for the beneficiation of titaniferous ores to produce a product high in titanium dioxide, and low in other metal oxides, which is suitable for use as a pigment, or is suitable for the subsequent production by chlorination of titanium dioxide pigments, or for the production of titanium metal.
  • ilmenite Commercial grades of ilmenite generally contain about 46 to 65% titanium dioxide combined with 30 to 45% iron oxides.
  • iron oxides and oxides of manganese and magnesium which substitute for iron oxides in the ilmenite lattice
  • the Murso process achieves this desired quality in six major steps:
  • titaniferous ores such as ilmenite contain a mixture of ferrous and ferric oxide.
  • the oxidation stage heats the material in a fluid bed or rotary kiln in the presence of excess atmospheric air. This treatment was required to ensure that all the ferrous oxide was converted to the ferric oxide form. There is then a crystal structure change that is beneficial to the following reduction stage.
  • the oxidised ore is reduced using either a solid or gaseous reducing agent to convert the ferric iron to the ferrous stage without continuing to the formation of metallic iron.
  • This conversion reaction makes the ore more amenable to the following leaching process which utilises hydrochloric acid.
  • the ore is preferably leached using a hydrochloric acid solution.
  • various improvements to the Murso process have resulted in (amongst other things) the addition to the leachate of metal chlorides, such as ferrous chloride, to facilitate the leach process.
  • the solids are filtered from the spent acid liquors and are washed with water and refiltered to remove the excess water.
  • the final step of recovering hydrochloric acid from ferrous chloride liquors is then undertaken to produce fresh hydrochloric acid which is recycled to the leach step, together with solid iron oxide which may be used as a feed material in the iron industry.
  • the present invention provides a process for the continuous leaching of treated titaniferous ores, said process comprising subjecting a treated titaniferous ore to an acid leach, wherein the acid leach uses interstage evaporators between leach stages.
  • the present invention provides a process comprising subjecting synthetic ilmenite to an acid leach, the synthetic ilmenite being produced by oxidising substantially all of the iron values associated with titanium in a titaniferous ore to the ferric state and by then reducing substantially all of the iron values to the ferrous state, wherein the acid leach uses interstage evaporators between leach stages.
  • more than one small interstage evaporator is utilised between various leach stages.
  • an optimum balance between acid strength and ion concentration can be achieved over several stages of leaching with only the water component produced by the reaction being removed.
  • the use of more than one evaporator and only removing a small portion of the water at each stage is also the most energy efficient method.
  • the number of leach stages is governed by the residence time required for complete dissolution of the iron and other metal oxides. For example, reaction times have been found to vary from one hour to six hours, depending on the feedstock, and as such the number of leach stages needed has varied from three to eight.
  • the number of evaporators used is generally dependent upon the number of leach stages.
  • the purpose of the leaching in the overall process is to dissolve selectively iron and other metal oxides from the ilmenite lattice with a minimum loss of titanium values.
  • some titanium does go into solution and a certain amount of it is subsequently precipitated from the solution as a fine material.
  • the main factors which affect the rate of leaching, production of fines, titanium, dissolution and its hydrolysis are acid concentration, mixing velocity and leaching temperature. Both high acid concentration and high temperature favour higher rate of leaching.
  • other factors such as titanium loss in solution, reduction of fines, materials of construction for leaching vessels, and economic recovery of hydrochloric acid influence the choice of acid strength, temperature of leaching and method of mixing.
  • the original Murso process found the optimum conditions for leaching to be 20% hydrochloric acid and a temperature of 108 to 110°C at atmospheric pressure in a fluid bed contactor. Subsequent variations to the Murso process discuss the merits of using a leachate with an increased chloride ion concentration over a hydrochloric acid solution but fail to describe a mechanism for maintaining . constant chloride concentrations in a continuous operation.
  • the removal of water produced during the reaction allows for the high level of chloride ion concentration to be maintained even towards the completion of the leach cycle when most of the acid has been depleted.
  • weak acid solutions extend the leach period and promote the formation of fine material, both of which are undesirable.
  • a further advantage of maintaining a high level of chloride ion concentration in the leach liquor is gained in the improved energy efficiency of the acid regeneration stage where a lower concentration of water requires less energy in the evaporation stages.
  • a low grade titaniferous ore such as ilmenite containing a mixture of ferrous and ferric oxide is subjected to temperatures in the order of 850 to 1000°C in the presence of excess air in a fluid bed or rotary kiln (oxidation reactor 10) for periods of one or more hours. Substantially all of the ferrous oxide is converted to the ferric oxide form and the ilmenite undergoes a crystal structure change that is beneficial to the following reduction stage.
  • the oxidised ore is then reduced (at reduction reactor 12) using either a solid reducing agent such as carbon or a gaseous reducing agent such as carbon monoxide, hydrocarbon gases, hydrogen or mixtures of these, to convert the ferric iron to the ferrous state without continuing to the formation of metallic iron.
  • Conversion of the oxidised product to the synthetic ilmenite is relatively rapid and efficient when carried out by hydrogen at 850 to 900°C.
  • the reduction step makes the synthetic ilmenite more amenable to the leaching process to be conducted with hydrochloric acid.
  • the synthetic ilmenite is then preferably leached in a counter current fluid bed system (indicated at 14 in Figure 1 and in detail in Figure 2) using a 15 to 20% hydrochloric acid solution containing 15 to 25% ferrous chloride at temperatures between 90 and 110°C.
  • This solution is made up by a combination of the fresh acid 16, the alcohol containing acid 18 and the ferrous chloride solution 20, and enters the system through the acid wash 24.
  • Two small interstage evaporators 22 are located between various leaching stages 26 to maintain an optimum balance between acid strength and ion concentration and to thus give an improvement in leach kinetics.
  • the removal of water in this way is also advantageous in later stages of the process due to a lower amount of energy being needed to evaporate the remaining water.
  • Vacuum flash evaporators are preferably used to ensure an acceptable efficiency of separation of water and acid between leaching stages. These evaporators and associated condensors enable 14% acid to be evaporated to 16% acid with little loss of acid to the condensate. The size of the evaporators will of course be dependent upon plant capacity and solution throughput.
  • An alcohol species is also preferably added to allow for lower temperatures to be used during leaching and to enhance the process economics as less energy is required to achieve the interstage evaporation required for chloride balance throughout the leach cycle.
  • the addition of an alcohol species is not essential for this invention.
  • the alcohol is added to the 31% HC1 solution 18.
  • the alcohol species added is substantially removed from the leachate by evaporation prior to the leachate being processed in the following acid regeneration stage. In this preferred form, allowance is made for a leachate nearly saturated in ferrous chloride to be regenerated again.
  • An acid washing stage 24 preferably concludes the leach cycle, and is preferably a counter current acid washing stage in a vessel similar to the leach vessels 26.
  • the wash acid from this stage advantageously becomes the feed acid to the leach circuit (via stream 28).
  • this acid wash, and also the acid leach may be conducted in any known manner that is appropriate, using any type of process and apparatus. In particular, counter-current or co-current operations may be used, or mechanical agitation or the like may be adopted.
  • the solids exiting from the acid wash 24 in stream 30 are then separated from the wash acid by filtration 32 and the filtrate is returned to the wash acid stage.
  • the now semi dried solids are dried 34 at controlled temperatures up to 400°C either in a fluid bed or rotary kiln to remove any contained acid, while the acid vapour is passed through recovery scrubbers 36.
  • the calcination process 38 for the dried solids is then conducted at 800 to 850°C for a period of 30 to 60 minutes to stabilise the crystal structure and to remove any final traces of moisture, iron chloride and hydrochloric acid.
  • the solid material can be passed through a magnetic field 40. to remove any incompletely leached material or any other magnetic material not effected by the acid leach.
  • the non magnetic fraction is recovered as the synthetic ilmenite product.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacture And Refinement Of Metals (AREA)

Abstract

L'invention permet la lixiviation, en continu par évaporation inter-phases des minerais titanifères traités. Elle s'intègre notamment dans un procédé d'enrichissement des minerais titanifères destinés à fournir un produit à forte teneur en dioxyde de titane et à faible teneur en autres oxydes métalliques, produit susceptible d'être utilisé comme pigment ou pour la fabrication ultérieure, par chloration, de pigments au dioxide de titane, ou pour celle du titane métal.
PCT/AU1993/000095 1992-03-09 1993-03-09 Lixiviation en continu par evaporation inter-phases de minerais-titaniferes traites Ceased WO1993018191A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU36236/93A AU3623693A (en) 1992-03-09 1993-03-09 Continuous leaching of treated titaniferous ores with inter-stage evaporation

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AUPL1296 1992-03-09
AUPL129692 1992-03-09

Publications (1)

Publication Number Publication Date
WO1993018191A1 true WO1993018191A1 (fr) 1993-09-16

Family

ID=3776035

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU1993/000095 Ceased WO1993018191A1 (fr) 1992-03-09 1993-03-09 Lixiviation en continu par evaporation inter-phases de minerais-titaniferes traites

Country Status (1)

Country Link
WO (1) WO1993018191A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7008602B2 (en) 2002-04-19 2006-03-07 Millennium Inorganic Chemicals, Inc. Beneficiation of titaniferous ore with sulfuric acid

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1225826A (fr) * 1967-05-01 1971-03-24
US3649243A (en) * 1969-07-31 1972-03-14 British Titan Products Beneficiating iron-containing titaniferous material
GB1314558A (en) * 1969-12-11 1973-04-26 Sachtleben Ag Method of enriching titanium-containing minerals in titanium
US4019898A (en) * 1976-04-30 1977-04-26 Benilite Corporation Of America Beneficiation of ilmenite ore

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1225826A (fr) * 1967-05-01 1971-03-24
US3649243A (en) * 1969-07-31 1972-03-14 British Titan Products Beneficiating iron-containing titaniferous material
GB1314558A (en) * 1969-12-11 1973-04-26 Sachtleben Ag Method of enriching titanium-containing minerals in titanium
US4019898A (en) * 1976-04-30 1977-04-26 Benilite Corporation Of America Beneficiation of ilmenite ore

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7008602B2 (en) 2002-04-19 2006-03-07 Millennium Inorganic Chemicals, Inc. Beneficiation of titaniferous ore with sulfuric acid

Similar Documents

Publication Publication Date Title
CA2044731C (fr) Methode d'extraction des mineraux utiles et des metaux precieux contenus dans des sables bitumineux ou dans d'autres corps mineralises connexes
CA2182123C (fr) Methode de production de rutile synthetique
EA009841B1 (ru) Способ восстановления металлов из материала, содержащего оксиды неблагородных металлов
US5023059A (en) Recovery of metal values and hydrofluoric acid from tantalum and columbium waste sludge
US4150976A (en) Method for the recovery of metallic copper
US3988224A (en) Method of extraction of metallic elements from submarine nodules
AU7558896A (en) Method to upgrade titania slag and resulting product
US7008602B2 (en) Beneficiation of titaniferous ore with sulfuric acid
US3770868A (en) Processing of manganese ores
US1503229A (en) Process of treating solutions of metals
US3951649A (en) Process for the recovery of copper
US2584700A (en) Treatment of iron ore containing impurities, including nickel and chromium
US4119696A (en) Production of titanium metal values
AU2020375443A1 (en) Vanadium recovery process
US4175110A (en) Recovery of titanium metal values
US4061712A (en) Recovery of vanadium values
CA1107973A (fr) Recuperation par lessivage au sulfate ferrique de l'argent, du cuivre et du zinc dans un concentre de pyrite partiellement grille
US4225564A (en) Purification of rutile
AU2017227985A1 (en) Process for the separation of vanadium
US4119697A (en) Production of titanium metal values
US3777013A (en) Process for the preparation of synthetic rutile starting from ilmenite
WO1993018193A1 (fr) Lavage a l'acide de solides ayant subi une lixiviation et provenant de l'enrichissement de minerais titaniferes
WO1993018191A1 (fr) Lixiviation en continu par evaporation inter-phases de minerais-titaniferes traites
WO1993018192A1 (fr) Lixiviation en continu par des solutions a base d'alcool de minerais titaniferes traites
US4423010A (en) Process for the selective removal of arsenic in the course of the oxidizing attack by means of a carbonated liquor on a uraniferous ore containing same

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AT AU BB BG BR CA CH CZ DE DK ES FI GB HU JP KP KR LK LU MG MN MW NL NO NZ PL PT RO RU SD SE SK UA US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN ML MR SN TD TG

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: CA