EP0755459A1 - Leaching of a titaniferous material - Google Patents

Leaching of a titaniferous material

Info

Publication number
EP0755459A1
EP0755459A1 EP95915693A EP95915693A EP0755459A1 EP 0755459 A1 EP0755459 A1 EP 0755459A1 EP 95915693 A EP95915693 A EP 95915693A EP 95915693 A EP95915693 A EP 95915693A EP 0755459 A1 EP0755459 A1 EP 0755459A1
Authority
EP
European Patent Office
Prior art keywords
silica
leach
acid
titaniferous
leaching
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.)
Withdrawn
Application number
EP95915693A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0755459A4 (enrdf_load_stackoverflow
Inventor
Ross Alexander Mcclelland
Michael John Hollitt
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.)
Technological Resources Pty Ltd
Original Assignee
Technological Resources Pty Ltd
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 Technological Resources Pty Ltd filed Critical Technological Resources Pty Ltd
Publication of EP0755459A1 publication Critical patent/EP0755459A1/en
Publication of EP0755459A4 publication Critical patent/EP0755459A4/xx
Withdrawn legal-status Critical Current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
    • 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
    • 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
    • C22B34/1204—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 preliminary treatment of ores or scrap to eliminate non- titanium constituents, e.g. iron, without attacking the titanium constituent
    • C22B34/1209—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 preliminary treatment of ores or scrap to eliminate non- titanium constituents, e.g. iron, without attacking the titanium constituent by dry processes, e.g. with selective chlorination of iron or with formation of a titanium bearing slag
    • 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
    • C22B34/1204—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 preliminary treatment of ores or scrap to eliminate non- titanium constituents, e.g. iron, without attacking the titanium constituent
    • C22B34/1213—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 preliminary treatment of ores or scrap to eliminate non- titanium constituents, e.g. iron, without attacking the titanium constituent by wet processes, e.g. using leaching methods or flotation techniques
    • 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 the removal of impurities from a titaniferous material.
  • titanium material is understood herein to mean a material which contains at least 2 wt% titanium.
  • the present invention provides a process whereby silica and alumina are removed from a titaniferous material using an aqueous leach in the presence of acid, with the effectiveness of the leach in removing these impurities enhanced by the combination of pretreatmen s and the conditions of the leach.
  • titanium dioxide bearing feedstocks are fed with coke to chlorinators of various designs (fluidised bed, shaft, molten salt) , operated to a maximum temperature in the range 700-1200°C.
  • chlorinators of various designs (fluidised bed, shaft, molten salt) , operated to a maximum temperature in the range 700-1200°C.
  • the most common type of industrial chlorinator is of the fluidised bed design.
  • Gaseous chlorine is passed through the titania and carbon bearing charge, converting titanium dioxide to titanium tetrachloride gas, which is then removed in the exit gas stream and condensed to liquid titanium tetrachloride for further purification and processing.
  • the chlorination process as conducted in industrial chlorinators is well suited to the conversion of pure titanium dioxide feedstocks to titanium tetrachloride.
  • most other inputs i.e. impurities in feedstocks
  • the attached table provides an indication of the types of problems encountered.
  • each unit of inputs which does not enter products contributes substantially to the generation of wastes for treatment and disposal.
  • Some inputs e.g. heavy metals, radioactives
  • Preferred inputs to chlorination are therefore high grade materials, with the mineral rutile (at 95-96% Ti0 2 ) the most suitable of present feeds. Shortages of rutile have led to the development of other feedstocks formed by upgrading naturally occurring ilmenite (at 40-60° Ti0 2 ), such as titaniferous slag (approximately 86% Ti ⁇ 2 ) and synthetic rutile (variously 92-95% Ti0 2 ) . These upgrading processes have had iron removal as a primary focus, but have extended to removal of manganese and alkali earth impurities, as well as some aluminium.
  • Si Accumulates Can encourage May require in duct distillation chlorinator, blockage. from product reducing Condenses in campaign part with life. titanium Consumes tetrachloride coke, chlorine
  • the titaniferous product of separation is treated with 2-5% aqueous sulphuric acid for dissolution of manganese and some residual iron.
  • aqueous sulphuric acid for dissolution of manganese and some residual iron.
  • Recent disclosures have provided a process which operates reduction at lower temperatures and provides for hydrochloric acid leaching after the aqueous aeration and iron oxide separation steps.
  • the process is effective in removing iron, manganese, alkali and alkaline earth impurities, a substantial proportion of aluminium inputs and some vanadium as well as thorium.
  • the process may be operated as a retrofit on existing kiln based installations. However, the process is ineffective in full vanadium removal and has little chemical impact on silicon.
  • ilmenite is first thermally reduced to substantially complete reduction of its ferric oxide content (i.e. without substantial metallisation), normally in a rotary kiln.
  • the cooled, reduced product is then leached under 35 psi pressure at 140-150°C with excess 20% hydrochloric acid for removal of iron, magnesium, aluminium and manganese.
  • the leach liquors are spray roasted for regeneration of hydrogen chloride, which is recirculated to the leaching step.
  • the ilmenite undergoes grain refinement by thermal oxidation followed by thermal reduction (either in a fluidised bed or a rotary kiln) .
  • the cooled, reduced product is then subjected to atmospheric leaching with excess 20% hydrochloric acid, for removal of the deleterious impurities.
  • Acid regeneration is also performed by spray roasting in this process.
  • ilmenite is thermally reduced (without metallisation) with carbon in a rotary kiln, followed by cooling in a nonoxidising atmosphere.
  • the cooled, reduced product is leached under 20-30 psi gauge pressure at 130°C with 10-60% (typically 18-25%) sulphuric acid, in the presence of a seed material which assists hydrolysis of dissolved titania, and consequently assists leaching of impurities.
  • Hydrochloric acid usage in place of sulphuric acid has been claimed for this process. Under such circumstances similar impurity removal to that achieved with other hydrochloric acid based systems is to be expected. Where sulphuric acid is used radioactivity removal will not be complete.
  • a commonly adopted method for upgrading of ilmenite to higher grade products is to smelt ilmenite with coke addition in an electric furnace, producing a molten titaniferous slag (for casting and crushing) and a pig iron product.
  • a molten titaniferous slag for casting and crushing
  • a pig iron product Of the problem impurities only iron is removed in this manner, and then only incompletely as a result of compositional limitations of the process.
  • a wide range of potential feedstocks is available for upgrading to high titania content materials suited to chlorination.
  • Examples of primary titania sources which cannot be satisfactorily upgraded by prior art processes for the purposes of production of a material suited to chlorination include hard rock (non detrital) ilmenites, siliceous leu ⁇ oxenes, many primary (unweathered) ilmenites and large anatase resources.
  • Many such secondary sources e.g. titania bearing slags also exist.
  • titania pigment by the choride process require feedstocks to have silica levels as low as possible. In general most feedstocks are less than 2% Si0 2 . Where, for various reasons, feedstocks with high levels of silica may be taken in, they are blended against other low silica feedstocks, often with significant cost and productivity penalties. Therefore suppliers of titaniferous feedstocks for chlorination traditionally select ores and concentrates which will result in beneficiated products with low levels of silica. This is generally achieved by mineral dressing techniques based on physical separations. In these processes it is only possible to reject essentially the majority of free quartz particles without sacrificing recovery of the valuable titania minerals. A level of mineralogically entrained silica will normally remain in titaniferous concentrates.
  • the present invention provides an industrially realistic process for upgrading of titaniferous materials, which process comprises the following steps:
  • pretreatment step (i) includes an aqueous caustic treatment.
  • the process of the invention can remove silica, alumina and other impurities.
  • the treatment in step (i) may include any treatment which has the effect of ensuring that the form of the silica in the titaniferous material entering step (ii) is amenable to alteration under the conditions of step (ii) .
  • the treatment may include smelting of the titaniferous material to make a titaniferous slag. It may include roasting of the titaniferous material with additives which have the effect in roasting of converting contained silica to silicates or transferring silica into a glassy phase.
  • the treatment may also be an alkaline leach treatment, with or without other additives, which has the effect of converting silica to amorphous or crystalline silicates.
  • the treatment may be a combination of these treatments or of these treatments and other treatments which in combination have the desired effect.
  • Step (i) may be conducted in any suitable equipment, which equipment will depend in part on the method chosen to perform this step.
  • Step (ii) is a leach conducted in the presence of acid.
  • Any suitable acid may be used, including hydrochloric and sulphuric acids, but also including weak acids such as organic acids and sulphurous acid.
  • the leach step must be conducted in such a manner that precipitation of silica to a solid precipitate or gel is avoided.
  • the most effective means of ensuring that hydrolysis is avoided is by conducting the leach at low solids densities, thereby limiting the level of silica in the solution.
  • the leach may be conducted in any suitable arrangement. Typically it will be conducted in stirred tank reactors. Leaching may be conducted in multiple stages or in a single stage, continuously or in batches. Solids and liquids flows through leaching may be cocurrent or countercurrent. Reagents may be added stagewise to maintain reagent strength through the leach or may be added in a single stage.
  • Solid/liquid separation may be conducted after leaching in any suitable manner, including cycloning, thickening, filtration, pressure filtration and centrifugation.
  • the spent leachant may be cycled through leachant treatment for the removal of impurities and back into the leach. Alternatively, spent leachant may be discarded or proceed to be used in other process stages.
  • the leach residue may pass to further processing, e.g. hot acid leaching for the removal of impurities such as iron, magnesium and manganese.
  • the leach residue may be washed.
  • the leach residue may be dried and/or calcined and/or agglomerated.
  • a bleed stream may be removed in order to limit the concentration of particular impurities.
  • a proportion of the wash liquors may be recycled as water make up.
  • the process may be preceded by upgrading of the titaniferous material for the removal of impurities such as iron, magnesium and manganese, and partial removal of silica and alumina.
  • Spent leachant and wash streams may report to leach/ acid regeneration circuits wherein any radioactive elements removed in leaching are deported to a suitable solid residue.
  • This example illustrates a multi stage pretreatment followed by a leach in the presence of acid which has the effect of silica removal.
  • a titaniferous concentrate was ground, mixed and agglomerated with the addition of 0.65% anydrous borax and 0.65% soda, added as sodium carbonate, and roasted with char at 1000°C.
  • the composition of the roasted product after char separation is given in Table 1. The roasting was conducted to enhance the amenability of silica in the feed to subsequent leaching by formation of a glassy phase.
  • the roasted material was subjected to leaching with boiling 45 gpL NaOH in the presence of 45 gpL Na2B407, 1.8 gpL Si0 2 and 0.66 gpL Al 2 0 3 under reflux at 5% solids density for 4 hours.
  • the leach residue (after solid/liquid separation and washing) contained 2.53% Si0 2 and 1.04% Al 2 0 3 . That is, silica and alumina removal was ineffective. However, with the exception of inert silica and alumina the form of alumina and silica in the residue had been converted to aluminosilicates of the feldspathoid type.
  • the leach residue was then subjected to room temperature (25°C) leaching with 100 gpL sulphurous acid at 10% solids density for 30 minutes. After solid/liquid separation and washing the residue of this leach contained 1.2% Si0 2 and 0.3% A1 2 0 3 . The precipitated aluminosilicate was completely removed.
  • a sample of a quartz bearing titania concentrate was fully oxidised with air at 900°C and then reduced in a fluidised bed using a hydrogen/C0 2 mixture such that the final state of virtually all contained iron was the 2+ oxidation state.
  • a 700g sample of this concentrate (whose composition is recorded in Table 2) was then leached at 40wt% solids density for 4 hours at 175°C in a solution made up by adding 242 g/L of 40% sodium silicate solution (3.2:1 Si0 2 :Na 2 0 weight basis) and 150g/L of NaOH.
  • Pellets of a ground titania slag (a product of ilmenite smelting) having a composition recorded in Table 3 were made up with addition of 1% Na 2 B 4 0 7 and roasted at 1000°C for two hours in a flow of 1:19 H 2 0/C0 2 gas mixture, to oxidise trivalent titania.
  • the caustic leached residue was subjected to an acid leach with 20% HCL at 30% solids density for 6 hours at reflux.
  • the composition of the residue of acid leaching is recorded in Table 4.
  • the combination of the caustic leach treatment with the acid leach treatment had been highly effective in the removal of silica in the acid leach.
  • Table 1 Composition of Thermally Processed Feed in Example 1. wt.% ⁇ io 2 63.4
  • Table 2 Compositions of Feed and Leach Residues in Example 2.
  • Table 4 Compositions of Caustic Leach and Subsequent Acid Leach Residues in Example 3.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Inorganic Compounds Of Heavy Metals (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Silicon Compounds (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
EP95915693A 1994-04-15 1995-04-18 Leaching of a titaniferous material Withdrawn EP0755459A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
AUPM5119A AUPM511994A0 (en) 1994-04-15 1994-04-15 Leaching of a titaniferous material
AUPM5119/94 1994-04-15
PCT/AU1995/000222 WO1995028502A1 (en) 1994-04-15 1995-04-18 Leaching of a titaniferous material

Publications (2)

Publication Number Publication Date
EP0755459A1 true EP0755459A1 (en) 1997-01-29
EP0755459A4 EP0755459A4 (enrdf_load_stackoverflow) 1997-02-26

Family

ID=3779699

Family Applications (1)

Application Number Title Priority Date Filing Date
EP95915693A Withdrawn EP0755459A1 (en) 1994-04-15 1995-04-18 Leaching of a titaniferous material

Country Status (10)

Country Link
EP (1) EP0755459A1 (enrdf_load_stackoverflow)
JP (1) JPH09512057A (enrdf_load_stackoverflow)
CN (1) CN1148412A (enrdf_load_stackoverflow)
AU (1) AUPM511994A0 (enrdf_load_stackoverflow)
BR (1) BR9507395A (enrdf_load_stackoverflow)
CA (1) CA2187892A1 (enrdf_load_stackoverflow)
IN (1) IN182628B (enrdf_load_stackoverflow)
NO (1) NO964351L (enrdf_load_stackoverflow)
WO (1) WO1995028502A1 (enrdf_load_stackoverflow)
ZA (1) ZA953046B (enrdf_load_stackoverflow)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5997606A (en) * 1997-08-11 1999-12-07 Billiton Sa Limited Production of titanium slag
US6713038B2 (en) 2000-04-18 2004-03-30 Millenium Inorganic Chemicals, Inc. TiO2 compounds obtained from a high silica content ore
US7625536B2 (en) * 2005-10-18 2009-12-01 Millennium Inorganic Chemicals, Inc. Titaniferous ore beneficiation
CN105543474B (zh) * 2015-12-21 2018-02-02 中南大学 一种钛铁矿转型精制除杂的方法
CN105967231A (zh) * 2016-06-22 2016-09-28 中国神华能源股份有限公司 一种从白泥中提取二氧化钛的方法
WO2018158492A1 (en) * 2017-03-02 2018-09-07 Outotec (Finland) Oy Method of treating titanium-containing slag
CN111646502B (zh) * 2020-06-10 2022-08-02 攀钢集团研究院有限公司 一种渣矿混合连续酸解浸取方法及设备

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2815272A (en) * 1955-03-10 1957-12-03 Nat Lead Co Method of producing titanium concentrates
BR8701481A (pt) * 1986-04-03 1988-01-19 Du Pont Processo para purificacao de minerio de tio2;e pigmento de tio2 obtido pelo processo
US5011666A (en) * 1988-07-28 1991-04-30 E. I. Du Pont De Nemours And Company Method for purifying TiO2 ore
AU4458993A (en) * 1990-03-02 1993-11-11 Wimmera Industrial Minerals Pty Ltd Production of synthetic rutile
AU639390B2 (en) * 1991-04-19 1993-07-22 Rgc Mineral Sands Limited Removal of radionuclides from titaniferous material
AU639178B2 (en) * 1991-04-19 1993-07-15 Rgc Mineral Sands Limited Conversion of ilmenite to synthetic rutile e.g. by the becher process
RU2121009C1 (ru) * 1992-07-31 1998-10-27 Ар-Джи-Си Минерал Сэндз Лимитед Способ упрощения удаления радиоизотопов, способ обработки железо- и титансодержащего материала
EP0658214A4 (en) * 1992-08-14 1996-07-03 Tech Resources Pty Ltd TREATMENT OF TITANIUM-CONTAINING MATERIALS.
BR9406464A (pt) * 1993-05-07 1996-01-30 Tech Resources Pty Ltd Processo para remover impurezas de um material titanífero
CN1042349C (zh) * 1993-09-07 1999-03-03 技术资源有限公司 提高含钛物料等级的方法

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
No further relevant documents disclosed *
See also references of WO9528502A1 *

Also Published As

Publication number Publication date
EP0755459A4 (enrdf_load_stackoverflow) 1997-02-26
BR9507395A (pt) 1999-08-31
AUPM511994A0 (en) 1994-05-12
IN182628B (enrdf_load_stackoverflow) 1999-05-22
JPH09512057A (ja) 1997-12-02
CN1148412A (zh) 1997-04-23
NO964351D0 (no) 1996-10-11
ZA953046B (en) 1996-01-15
NO964351L (no) 1996-12-10
WO1995028502A1 (en) 1995-10-26
CA2187892A1 (en) 1995-10-26

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