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
  • C22B34/1218—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 dry processes
  • C22B34/1222—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 dry processes using a halogen containing 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
  • C22B1/00—Preliminary treatment of ores or scrap
  • C22B1/14—Agglomerating; Briquetting; Binding; Granulating
  • C22B1/16—Sintering; Agglomerating
• • 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
  • C22B1/00—Preliminary treatment of ores or scrap
  • C22B1/14—Agglomerating; Briquetting; Binding; Granulating
  • C22B1/24—Binding; Briquetting ; Granulating
  • C22B1/242—Binding; Briquetting ; Granulating with binders
• • 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
• • 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

Definitions

• the present invention relates to processes for making agglomerates of titanium-bearing particles and to processes for the preparation of upgraded products therefrom.
• the objective is the removal of impurities, especially iron compounds, with associated increase in proportion of contained titania.
• the upgraded titania product in these cases would represent a useful feed to either acid digestion or carbochlorination as the first steps in the production of titania pigments.
• the primary step is chemical reaction to produce an intermediate product (titanium sulphates or chlorides in aqueous solution or liquid titanium tetrachloride) .
• an intermediate product titanium sulphates or chlorides in aqueous solution or liquid titanium tetrachloride
• Many of the elements associated with the titania in the feed, and especially any iron which is present also become involved in the reaction and consume the active reagent (acid or chlorine). This reaction of associated elements has the economic penalty of excessive reagent consumption in primary reactions, and the economic and environmental penalties associated with separation of valuable titanium compounds from impurity compounds and the disposal of separated wastes.
• Prior art processes exist for the upgrading of titanium bearing minerals to products containing relatively high levels of contained titanium dioxide (greater than 75% titania expressed as TiOschreib ) .
• the most advantageous of these processes utilise elevated temperature oxidation and reduction of titania feedstocks prior to removal of contained iron values by a method which does not consume appreciable quantities of chemical reagents overall.
• the elevated temperature treatment involves contacting of solid particulate minerals with hot gases.
• the contacting device is a fluidised bed or a kiln (e.g. grate or rotary) in which the mineral residence time is appreciable (e.g. several hours).
• ilmenite The most common type of mineral which is fed to upgrading processes is generically termed "ilmenite".
• ilmenite refers to iron bearing titaniferous minerals which may structurally include true ilmenite, pseudobrookite, pseudorutile, titanomagnetite and rutile.
• Ilmenite occurs naturally in sand and rock deposits, and is frequently fine grained. Fine grained ilmenite cannot be treated in gas/solid contacting devices forming part of the prior art upgrading processes .
• a process for providing a titaniferous mineral of improved particle size which process comprises mixing fine mineral with a binding agent and water to form a mixture, impacting and shearing the mixture to produce a micro-agglomerate, and drying the micro-agglomerate.
• the source of titanium-containing mineral may be any titanium-containing mineral which is chemically suited to upgrading.
• the titanium-containing mineral may be natural or synthetic in origin.
• the titanium-containing mineral may be a detrital mineral.
• the titanium may be present in the titanium-containing mineral in the form of titanium dioxide.
• the titanium-containing mineral may contain up to 20 per cent of grains which have little contained titanium.
• the amount of water added may vary depending upon the size distribution of the original particles of the titanium-containing mineral and the required size of the agglomerated product.
• the amount of water may vary from approximately 5 to 17% by weight, preferably 10-12% by weight, based on the total weight of titanium-containing mineral, binder and water.
• the binder or binders for the titanium-containing particles may be of any suitable type.
• the binders for the titanium—containing particles should be such as to form agglomerates, also known as micro-agglomerates, which are capable of withstanding the physical, chemical and thermal degradation forces in drying and any subsequent thermal treatment processes, including gas/solids contacting.
• the binders may be organic or inorganic binders.
• the binders may be ceramic or glass-forming binders.
• the binders may be carbon-free binders.
• a single binder may be used.
• a combination of two or more binders may be used to provide strength under the different operating environments of the drying and subsequent treatment stages.
• the binder for the titanium-containing minerals may be such that it does not seriously contaminate the bound titanium bearing particles for subsequent processing, for example in upgrading processing.
• the binder for the titanium-containing particles may include:
• the amount of binder for titanium-containing particles in the micro-agglomerate should ideally be sufficient to produce a strong competent micro-agglomerate.
• the amount of binder should preferably not be sufficient to encapsulate the titanium-containing particles.
• a relatively low percentage of binder is preferred. Percentages in the range of approximately 0.5 - 5% by weight are preferred.
• the impacting and shearing step in the process of the present invention is advantageously conducted in devices incorporating an impaction/shearing action such as high intensity micro-agglomerators having high speed blades such that blade tip speed is in the range 50 - 1000m sec. .
• This high intensity action may optionally be coupled directly or indirectly with a rolling/tumbling action, although a key feature of the present invention is the incorporation of the high intensity action.
• Agglomeration may be conducted in stages or in closed circuit with product sizing screens.
• the drying step may be conducted at elevated temperatures.
• a separate drying step may not be necessary.
• the drying step may be conducted at elevated temperatures from 75 to 100°C.
• the drying step is preferably carried out in such a manner as to limit the residence time of the micro-agglomerates in this part of the process to less than 30 minutes.
• the drying step may be conducted in any suitable drying apparatus.
• a fluidised bed dryer or rotary dryer may be used.
• the agglomerated particles also called micro-agglomerates, may be manufactured to fall within a preferred size range to suit the dynamic requirements of gas/solids contacting devices. In most such devices it will be advantageous if the weight averaged particle size for the agglomerated product is coarser than 100pm diameter. It is also advantageous for many high temperature physical and chemical processing operations if the average agglomerate particle size is less than 2mm diameter.
• a micro-agglomerate comprising 95 to 99.5% by weight of fine particles of a titaniferous mineral bound together with 0.5% to 5% by weight of a binding agent wherein titaniferous mineral has an average particle size in the range from 0.05 to 100 m and the micro-agglomerate has an average particle size in the range from 100pm to 2mm.
• the agglomeration process as disclosed herein may be used for the incorporation of desired additives having beneficial chemical or physical effects in subsequent gas/solids contacting steps or with the effect of imparting a particular physical or chemical property to upgraded products formed from titanium bearing minerals.
• the presently disclosed process by virtue of the high intensity nature of the agglomeration step, is effective in ensuring highly homogeneous incorporation of powdered additives.
• the process may include the preliminary step of grinding at least a portion of the titanium-containing particle source.
• the preliminary grinding step may be utilized to improve the size control in the preparation of the micro-agglomerates and thus provide the finished product with a greater strength and density.
• the titanium-containing particles may be introduced into any suitable grinder. A ball mill or rod mill may be used. Hammer or ring mills may also be used.
• the amount of titanium-containing feed to be ground may vary from zero to approximately 100% by weight depending on the source and type of titanium-containing ore.
• the grinding step may provide particles having an average size from approximately 5pm to approximately 100pm.
• the moist or dried product of agglomeration may optionally be treated in a high temperature firing step to produce a granular titanium-containing product of sufficient strength for storage, handling and transportation, or treatment in a subsequent upgrading process, without appreciable degradation.
• the high temperature gas/solids contacting step of the upgrading process may be used to simultaneously fire the agglomerated product.
• the temperature and residence time should be sufficient to produce homogeneous or heterogenous phase bonding between the particles within the micro-agglomerates.
• the micro-agglomerates may be heated to a temperature of approximately 900°C to 1500°C, preferably 1000°C to 1200°C.
• the residence time of the micro-agglomerates within the temperature range may be for a period of several minutes to approximately 10 hours.
• Significant chemical and physical changes may occur in the firing step.
• Additives incorporated into the agglomerates in the agglomeration step may become dissolved in or react with titanium bearing particles in the firing step. Reduction or oxidation reactions may be carried out in the firing step.
• Iron contained within the titanium bearing particles may be reduced to the ferrous oxidation state or to metallic iron. Titanium dioxide may be reduced to form phases containing more reduced titanium oxides.
• the firing step may be carried out by any suitable means, including a fluidised bed, in an oven or kiln.
• Heat may be applied by combustion of coal, fuel oil, natural gas or any other suitable fuel.
• Fuel combustion may be carried out with or without addition of oxygen, or oxygen enrichment or combustion air. Where reduction reactions are desired during firing solid carbon sources or gaseous reductants may be used.
• a titanium-containing material formed according to the preparation process described above may include a plurality of sintered micro-agglomerated particles.
• the bond formed between the titanium-containing particles may include particle boundary recrystallisation wherein the boundaries of the titanium containing particles may be physically merged.
• the bond formed between the titanium-containing particles may also consist of a separate bridging phase formed by the binder or product phases formed by chemical reaction in a firing or curing step.
• the operation of a firing step may tend to eliminate the binder from the micro-agglomerated particles by evaporation, gasification or combustion.
• the initially added binder may be present in the titanium bearing agglomerated product and/or may be incorporated in whole or in part in crystalline phases forming the product.
• the titanium bearing granules so formed may optionally be subjected to further treatment after heat curing. In one form the heat cured granules may be subjected to subsequent classical treatment to upgrade the titanium content. The granules may be provided with sufficient strength to withstand the subsequent chemical treatment.
• the heat cured granules may be provided with only sufficient strength to withstand a firing process.
• the granules may then be easily degraded during further processing treatment, for example for removal of contained metallic iron, such that a liberated fraction of contaminant grains may then be removed.
• the granules may be degraded physically or chemically for this purpose.
• Agglomerates were prepared from an ilmenite mineral fraction derived from a mineral sands deposit located near Horsham in Western Victoria.
• the ilmenite mineral consisted of fine sand in the size range 45um to 65um.
• a laboratory scale batch Patterson-Kelley high intensity blender was used initially to blend a dry mixture of 9 kg of the ilmenite with 1% of -50pm ilmenite fines and 0.7% bentonite binder for two minutes. Water containing 1% PVA was then added at a controlled rate by spraying through a rotating central shaft within the blender on which was mounted high speed mixing blades. (The central shaft is known as an "intensifier bar").
• the intensifier bar rotated at a speed of 1500-3000 rpm, serving both to shear the solids and to spray the water into the charge in a finely divided and well distributed form.
• the amount of water added in this way was 15% on a wet weight basis.
• the blender was allowed to continue to act on the charge for a further minute after completion of water addition, which required about four minutes.
• Dry agglomerate strength was assessed using a load cell to determine the force withstood to the point of failure, and this force averaged 0.11N over 30 tests.
• Dry agglomerates were mixed with powdered charcoal and then fired in a muffle furnace at 1150°C for 5 hours. Breakage force after firing was on average 0.28N.
• Agglomerates were prepared in identical manner to that described in Example 1, with the exception that 2% bentonite rather than 0.7% was used in the original blended mix.
• Size analysis of the product gave the following distribution: Size range %
• Example 2 The dry agglomerates exhibited an average strength which could withstand 0.28N loading. Subsequent reduction firing as in Example 1 resulted in an average breaking force of 1.46N.
• material produced according to this method may be applied to applications for which a coarse product is desired, for example in dry handling or in gas/solids contacting as would be carried out in chlorination for titanium tetrachloride formation.
• Firing of dry agglomerates prepared according to the method described in Example 1 was carried out in the absence of reductant, in air at 1150°C for five hours in a muffle furnace.
• the fired product agglomerates exhibited strengths which could withstand an average loading of 3.7N.
• the fired product exhibited considerable bridging between particles and was highly suited for processing operations involving gas/solids contacting.
• Horsham ilmenite according to the manner described in Example 1.
• a sample of 400g of the agglomerates was admixed with 400g of renovated brown coal char and fired in a high temperature steel crucible in a muffle furnace for two hours at 1180°C.
• the fired reduced agglomerates were allowed to cool, were separated from the residual char, and were then added to 1.8L of water at 50°C, containing 1% ammonium chloride.
• Air was introduced to the mixture at 500 cc/min over a ten hour period whilst strongly agitating the mixture.
• Ilmenite and contaminant particles were completely liberated by disintegration of the agglomerates during the "rusting" step.

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• 1989
  • 1989-07-25 JP JP1508146A patent/JP2779028B2/ja not_active Expired - Fee Related
  • 1989-07-25 BR BR898907582A patent/BR8907582A/pt not_active IP Right Cessation
  • 1989-07-25 KR KR1019900700646A patent/KR900702059A/ko not_active Application Discontinuation
  • 1989-07-25 EP EP89908683A patent/EP0426731B1/en not_active Expired - Lifetime
  • 1989-07-25 DE DE68915446T patent/DE68915446T2/de not_active Expired - Fee Related
  • 1989-07-25 WO PCT/AU1989/000314 patent/WO1990001072A1/en unknown
  • 1989-07-25 RU SU894894816A patent/RU2080396C1/ru active
  • 1989-07-25 AU AU39898/89A patent/AU626191B2/en not_active Ceased
  • 1989-07-25 AU AU39897/89A patent/AU626155B2/en not_active Expired
  • 1989-07-25 KR KR1019900700645A patent/KR0148343B1/ko not_active IP Right Cessation
  • 1989-07-25 WO PCT/AU1989/000315 patent/WO1990001073A1/en active IP Right Grant
  • 1989-07-25 AT AT89908683T patent/ATE105873T1/de not_active IP Right Cessation
  • 1989-07-26 CA CA000606689A patent/CA1340279C/en not_active Expired - Fee Related
  • 1989-07-26 ZA ZA895676A patent/ZA895676B/xx unknown
  • 1989-07-26 ZA ZA895675A patent/ZA895675B/xx unknown
• 1991
  • 1991-01-25 OA OA59939A patent/OA09635A/en unknown

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