JPH029094B2 - - Google Patents

Description

[Detailed description of the invention]

Industrial Application Field This invention is based on titanium ore, especially anatase ore.
The present invention relates to a smelting method that efficiently removes impurities present in ore when extracting Ti or Ti compounds, and also separates and recovers valuable components contained therein. Conventional technology In the 1970s, it was discovered that there were large reserves of TiO ₂ with an anatase structure (hereinafter referred to as anatase ore) in Brazil, which was known only academically until recently. Treatment methods have been attracting attention. However, because the invention of this ore is relatively new, and the production volume of rutile and ilmenite, which are the raw materials for Ti or TiO ₂ , meets the current demand, Ti or TiO ₂ from anatase ore is not available.
At present, not much research has been conducted on the production of However, due to the excellent properties of Ti or TiO ₂ ,
With predictions that demand will increase in the future, several studies have recently begun to be conducted on methods for processing anatase ore. For example, (1) "Method for enriching titanium ore" (Japanese Patent Publication No. 56-373), after calcining and reducing anatase ore,
This is a method of obtaining a non-magnetic part rich in anatase ore by magnetic separation, removing impurities from it by acid leaching, and further removing phosphorus, which is an anti-rutile impurity, by alkali treatment to obtain anatase concentrate with a TiO ₂ content of 90% or more. . (2) “Method for processing anatase ore”
2163), after converting anatase ore into titanium concentrate through scrubbing and specific gravity beneficiation,
This is a method of melting and smelting this in the presence of a carbonaceous reducing agent to concentrate the titanium content in the slag, producing a high titanium slag with a TiO ₂ content of 70% or more. (3) “Method for producing anatase concentrate”
No. 48852), the coarse part of anatase ore that has been deslimed is milled and then magnetically separated, and the non-magnetic part is subjected to partial reduction to replace the limonite etc. contained in it with magnetic iron oxide. This method involves removing it by magnetic separation and electrostatic separation of the remainder to obtain anatase concentrate rich in anatase. (4) “Preparation method of raw material for anatase”
48853), after deagglomerating anatase ore containing 25% TiO ₂ , it is subjected to treatments such as sieving, pulverization, classification, and magnetic separation to convert relatively coarse anatase raw material containing 50% TiO ₂ to 60% or more. A method for collecting the yield is shown. That is, the above method is an application of a conventional method for concentrating TiO ₂ from ilmenite and low-grade titanite to anatase ore. In other words, known beneficiation methods (acid leaching, magnetic separation, etc.) and Ti slag production methods are used. Problems to be Solved by the Invention Incidentally, unlike ilmenite ore, anatase ore is produced in carbonatite deposits, so it contains impurities such as P, Ca, and Al, as well as small amounts of rare metals such as Nb, Zr, and
Contains valuable components such as Ca and La. Then,
When extracting Ti or Ti compounds from anatase ore, the above impurities are efficiently removed, and
It is thought that the resource potential of anatase ore will be increased by separating and recovering the above-mentioned valuable components. However,
The proposed treatment method focuses only on the concentration of TiO ₂ and does not propose recovery of valuable components. In addition, although anatase-type TiO ₂ and γ-Fe ₂ O ₃ (gamma-hematite), which are the main components of anatase ore, exist as separate phases, there are many parts where they are finely mixed with each other, and γ-Fe ₂ O The solid solution of TiO ₂ in ₃ and the solid solution of Fe ₂ O ₃ in the TiO ₂ phase both range from a few percent to about 10%, and can be achieved by simply using acid leaching after mechanical crushing or magnetic separation after partial reduction. Even if there is, it is difficult to recover high-quality TiO ₂ (TiO ₂ content of 90% or more) with good yield. This is clear from the examples of the proposed invention. Means and action for solving the problem Therefore, the present inventors have attempted to efficiently remove the impurities contained in anatase ore, and to
As a result of various studies on methods that can separate and recover valuable components when extracting compounds, we have found that (1) According to thermodynamic studies on carbon reduction of TiO ₂ , TiO is removed during reduction. Since TiO is very stable, it is necessary to obtain Ti from it under reduced pressure.
Although heating above 2500℃ is required, _TiO2
(2) In the reduction and carbonization reaction of TiO ₂ , Fe ₂ O ₃ coexisting with TiO ₂ is It is reduced to α・
This α・Fe absorbs carbon at temperatures above 1200°C and exists as carbon-saturated molten iron, and the saturated carbon in this molten iron promotes the reduction and carbonization of TiO ₂ and rapidly generates TiC. (3 ) When titanium ore is reduced and carbonized at temperatures above 1200℃, a product consisting of a TiC carbide phase, a metallic iron phase, and an oxide phase is obtained; in this case, Nb and Zr are TiC
S and P are concentrated in the carbide phase, S and P are concentrated in the metallic iron phase, and the oxides of Ce, La, Ca and Al are stable and therefore remain in the product without being reduced; (4) directly from TiO ₂ ; Chlorination is impossible with either Cl ₂ or HCl at temperatures below 2000℃, but with TiC
Chlorination with Cl ₂ gas proceeds at a much lower temperature than TiO ₂ chlorination. (5) When combining the TiC chlorination treatment with acid treatment or magnetic separation, each component
They discovered that Ti, Fe, Nb, Zr, Ce, La, etc. can be easily separated and recovered. This invention has been achieved based on the above knowledge, and therefore, the present invention extracts a titanium raw material suitable for the production of metallic titanium or titanium oxide by the chlorine method from titanium ore, and also extracts titanium raw material contained in the ore. This is a smelting method for separating and recovering valuable components of titanium ore, including: (a) blending a predetermined amount of carbonaceous material with titanium ore and mixing thoroughly; (b) heating the mixture at a temperature below its melting temperature. The product is reduced and carbonized to produce a product consisting of a carbide phase, a metallic iron phase, and an oxide phase consisting mainly of components other than Ti and Fe; Either the mixed chloride mainly consisting of TiCl ₄ and FeCl ₃ is separated into a chloride residue, or the magnetic material is removed by magnetic separation and the non-magnetic material is collected, and the non-magnetic material is leached with acid to remove the iron content. ( _{d) The mixed chloride or the chloride is separated into TiCl 4 ,} FeCl ₃ , NbCl ₅ and ZrCl ₄ by fractional distillation. (e) providing the chlorinated residue as a raw material for extraction of Ce and La;
A method for smelting titanium ore, which is characterized by consisting of various steps, as well as for extracting a titanium raw material suitable for manufacturing titanium metal or titanium oxide using the chlorine method from titanium ore, and for extracting valuable components contained in the ore. It is also a smelting method for separating and recovering titanium ore, which involves: (a) blending a predetermined amount of carbonaceous material with titanium ore and thoroughly mixing it; (b) reducing and carbonizing the mixture at a temperature higher than its melting temperature. , TiC phase, metallic iron phase and mainly
(c) The product is mechanically exfoliated to form a carbide phase,
The metallic iron phase and the oxide phase are separated, and (d) the carbide phase is subjected to a low-temperature chlorination treatment to mainly
(e) The chloride is separated into TiCl ₄ and chloride residue by fractional _distillation .
A method for smelting titanium ore, comprising the steps of separating NbCl ₅ and ZrCl ₄ , respectively, and (f) using the chloride residue as a raw material for extracting Ce and La. The method of the present invention is completely different in concept from the above-mentioned proposed invention and other conventionally proposed methods for treating Ti-containing ores. That is, as a first step, the amount of carbonaceous material required to reduce TiO ₂ and Fe ₂ O ₃ contained in anatase ore to TiC and metallic iron, respectively (hereinafter referred to as carbon equivalent), is added to the ore. After mixing at 1200℃
Reduction and carbonization are performed in the above manner, and TiC and metallic iron are first produced. In this case, Ce, La,
Since the oxides of Ca and Al are stable, they are not reduced and remain in the product as oxides. Next, in the second and subsequent stages, the reduction and carbonization products are treated using methods such as chlorination, acid leaching, or magnetic separation to separate each component, namely Ti, Fe, Nb, Zr, Ce,
The idea is to separate and recover La, etc. The reduction/carbonization step and separation/recovery step described above will be explained below with reference to the processing system diagrams of FIGS. 1 and 2, which show preferred processing steps of the present invention. Figure 1 shows the case where the reduction and carbonization of a mixture containing carbonaceous materials is carried out at a temperature of 1200℃ or higher and below the melting temperature of this mixture. This relates to the case where it is carried out in a state. Reduction and carbonization process Prior to reducing and carbonizing anatase ore, a reduction experiment was conducted using a reagent oxide. That is, the TiO ₂ single and (TiO ₂ + Fe ₂ O ₃ ) mixed oxides (TiO ₂ /Fe ₂ O ₃ ratios were the same as in the case of anatase ore (TiO ₂ : 36.2%, Fe ₂ O ₃ : 43.5%). We investigated whether the reduction of TiO ₂ was further promoted by the presence of Fe. Figure 3 shows the reduction rate when the carbon equivalent is 1.0 and reduction treatment is performed at each temperature for 3 hours.
The x mark indicates the case of TiO ₂ alone, and the ○ mark indicates the case of the above mixed oxide. In the figure, the circle mark indicates the reduction rate calculated from each reduction rate of the mixed oxide, assuming that all Fe ₂ O ₃ has been reduced to α・Fe, and to what extent the coexisting TiO ₂ has been reduced. It can be seen that nearly 90% of the amount is reduced at 1300℃. As described above, it was found that the coexistence of Fe creates a situation in which TiO ₂ is more easily reduced. The reason for this is that in the case of a mixed oxide, the temperature at 1000℃ is lower than in the case of a solid-solid reaction between simple TiO ₂ and carbon.
The reduced Fe absorbs carbon and lowers its melting point, so that it exists as carbon-saturated molten iron at temperatures above 1200℃, which comes into contact with TiO ₂ and the reduction is further promoted by the carbon in the molten iron. I can think about it. According to the treatment method shown in Fig. 1, after blending anatase ore with a specified carbon material and thoroughly mixing it, it is preferably pelletized and reduced at a temperature of 1200°C or higher and lower than the temperature at which the mixture melts. Carbonization is performed to convert TiO ₂ and Fe ₂ O ₃ contained in the ore into TiC and metallic iron, respectively, and into Ce, La, Ca,
Products such as Al are directly contained as oxides. The above carbon materials include coke, graphite,
Charcoal etc. are used, and the blending amount is TiO ₂ and Fe ₂ O ₃
The amount of carbon (carbon equivalent) required to make TiC and metallic iron, respectively, or an amount in excess thereof is preferably 1.2 to 1.5 times the required amount. In this reduction/carbonization reaction (hereinafter referred to as solid phase reduction), iron oxide is reduced to iron at about 1000℃, as described in the reduction test above, but at 1200℃
In the above, carbon is absorbed, the melting point is lowered, and it exists as carbon-saturated molten iron. The saturated carbon in this molten iron promotes the reduction and carbonization of TiO ₂ and rapidly generates TiC. Note that the oxides of Ce, La, Al, and Ca are not reduced due to their reducibility and remain in the product as an oxide phase, separate from the carbide phase and metallic iron phase. ,
Zr has a carbide phase mainly composed of TiC, Ti and
P, which is a harmful impurity to TiO ₂ , is distributed in the metallic iron phase together with Si. The solid phase reduction can be carried out at a temperature of 1200 to 1300°C using, for example, a rotary kiln as a heating furnace. Figure 4a is a scanning electron micrograph showing the particle structure of the product obtained by solid-phase reduction (1300°C, 3 hours treatment) using a siliconite electric furnace, and Figure 4b is an explanatory diagram thereof. It can be seen that although phase A, α-Fe phase B, and oxide phase C are separated, each phase intercalates and mixes with each other. On the other hand, Figures 5a and 5b shown for comparison are scanning electron micrographs and their explanatory diagrams when solid-phase reduction was carried out at 1100°C.
is a Ti oxide phase, and B is an α-Fe phase. 1100℃
However, the three phases described above have not been clearly formed, and in order to proceed with the reduction and carbonization reaction, it is necessary to proceed with the action of the carbon-saturated molten iron mentioned above.
It can be seen that a temperature of 1200℃ or higher is required. On the other hand, as shown in the processing system diagram in Figure 2,
When the mixture is reduced and carbonized at a temperature higher than the melting temperature of the mixture (hereinafter referred to as smelting reduction) using an arc furnace or a plasma arc furnace as a heating furnace, that is, in a molten state, for example, 2000°C or higher, the solid phase The reduction reaction proceeds more rapidly than in the case of reduction. Specifically, as the reaction progresses in the molten state, TiC separates and precipitates as a solid phase due to its low solid solubility in molten iron, and the oxide phase becomes a so-called slag phase and floats and separates on top of the molten iron. do. Therefore, after cooling, the metallic iron phase, TiC carbide phase, and oxide phase separate into layers.
If each phase is separated and recovered by mechanical stripping, or if the molten iron and molten slag are discharged from the furnace when they are in a molten state, the treatment is simpler and easier than in the case of solid phase reduction. Separation and recovery process The product obtained by the solid-phase reduction described above is cleaved using a ball mill or the like, and then subjected to low-temperature chlorination treatment at a temperature of about 300°C. The chlorination of TiC with chlorine gas is generally carried out at a lower temperature of 300 °C compared to the chlorination of _TiO2 , which is carried out at a high temperature of 800 °C or higher.
The chlorination reaction proceeds sufficiently at about ℃ to obtain TiCl ₄ . Metallic iron is also easily chlorinated to FeCl ₃ at around 300°C, so in this case TiCl ₄
A mixed chloride of -FeCl ₃ will be obtained.
On the other hand, at a chlorination temperature of about 300°C, oxides containing Ce, La, etc. are not chlorinated and remain in the residue even if carbonaceous materials coexist, and are separated from the Ti and Fe components to be chlorinated. In other words, carbonaceous material and oxide phase remain in the chloride residue, so by calcining this in air and eliminating the carbonaceous material as CO ₂ ,
Mixed oxides enriched with Ce and La (CaO,
(including Al ₂ O ₃ etc.), which can be used as a raw material for recovering Ce and La. Next, TiCl ₄ − obtained by low-temperature chlorination
FeCl ₃ mixed chloride can be easily fractionated by taking advantage of the fact that the vapor pressure of TiCl ₄ is higher than that of FeCl ₃ , and this mixed chloride also contains small amounts of NbCl ₅ , ZrCl ₄ , and SiCl _{4 .} These are also separated and recovered by a conventional fractional distillation method that utilizes the difference in distillation temperature. Apart from the above-mentioned method of subjecting the solid-phase reduction product directly to low-temperature salting treatment, the following method can be used more preferably. That is,
By first subjecting the product consisting of TiC carbide phase, metallic iron phase and oxide phase to magnetic separation, most of the iron in the ore can be removed, and the iron remaining in the non-magnetic part can be removed. The TiC and oxide phase are recovered by acid leaching. Next, TiC is selectively chlorinated by subjecting it to low-temperature chlorination treatment, and TiCl ₄ is recovered. On the other hand, as described above, the oxide remains in the chloride residue and becomes the raw material for Ce and La. Regarding the product obtained by the melt reduction,
Since the TiC carbide phase is easily separated into the carbide phase, metallic iron phase and oxide phase as mentioned above, the TiC carbide phase can be easily separated into the carbide phase, the metallic iron phase and the oxide phase using chlorine gas.
TiCl ₄ is recovered by low-temperature chlorination treatment at about ℃. In this case, a small amount is included in the carbide phase.
Although NbCl ₅ and ZrCl ₄ are also included in the recovered TiCl ₄ , they are each recovered by a conventional fractional distillation method using a vapor pressure difference. Also, as in the case of solid-phase reduction, the oxide phase serves as a raw material for Ce and La. Next, the present invention will be explained with reference to examples. Example 1 Anatase ore (produced in Brazil) with the chemical composition shown in Table 1 was milled into powder of 200 mesh or less in a closed circuit with a vibrating sieve using a wet ball mill, and then dried to a moisture content of approximately 5% by excessive dehydration. did. Approximately 40% of fine graphite (corresponding to a carbon equivalent of 1.37) was blended with this dry ore, thoroughly mixed, and then granulated into pellets with a diameter of 5 to 10 mm using a dish granulator. The above granules are then processed using a rotary kiln.
It is heated at 1300℃ for 1 hour to undergo reduction and carbonization treatment.
The obtained product was further pulverized.

【table】

[Table] Next, 5 kg of the above-mentioned shattered material was collected and passed through a dry magnetic separator with a magnetic field of 600 Gauss to remove 2.18 kg of metallic iron as magnetic material, and 2.82 kg of non-magnetic material was collected.
In order to remove iron remaining in this non-magnetic material, it was further leached with 6N.H ₂ SO ₄ and washed with warm water to obtain 2.57 kg (dry weight) of leached residue. Next, this acid leaching residue was subjected to low-temperature chlorination treatment at 300° C. by passing chlorine gas therein while stirring. After washing with 0.6 kg of water, the composition of each component in 6.6 kg of the mixed chloride solution obtained was as shown in Table 2. The residue after chlorination (approximately 0.7 kg) mainly consisted of oxides, the composition of which is shown in Table 3, and was used as a raw material for CcO ₂ and La ₂ O ₃ . In addition, TiCl ₄ was obtained by chlorination treatment.
The recovery rate for Ti was approximately 95%, and the same was true for Nb and Zr obtained as chlorides.

【table】

[Table] Since each chloride in the above mixed chloride solution has different vapor pressure as shown below, each component was fractionated using a conventional fractionator. TiCl ₄ ...Melting point: -23℃, boiling point: 136.4℃ NbCl ₄ ...Melting point: 205℃, boiling point: 250℃ ZrCl ₄ ...Melting point: 437℃ In other words, since the vapor pressure of TiCl ₄ is high, first the temperature above 100℃ is By heating the solution, expelling TiCl ₄ from the system, and cooling it below 0°C.
TiCl ₄ was separated and recovered. Furthermore, NbCl ₅ and ZrCl ₄ were also separated and recovered by changing the respective temperatures. Each metal chloride obtained after the fractional distillation can be used as a raw material to be subjected to a well-known method, for example, a reduction method using Mg. On the other hand, the reduction carbonization product was directly subjected to chlorination treatment without performing iron removal by magnetic separation or acid leaching as described above. That is, 5 kg of the cracked material was collected and subjected to low-temperature chlorination treatment using chlorine gas in the same manner as the previous time. The composition of each component in 14.5 kg of the mixed chloride solution obtained by washing with water in step 1.3 after completion of the chlorination is shown in Table 4, and the residue after chlorination (approximately 0.7 kg) is CeO ₂ as before.
It was used as a raw material for La 2 O 3 and La ₂ O ₃ . The recovery rate of each component obtained as chloride through the chlorination treatment was about 95%, the same as the previous time. In the case of direct chlorination treatment, about twice as much chlorine gas is required as compared to the case where chlorination treatment is performed after iron removal as described above.

[Table] In the above-mentioned fractional distillation of mixed chlorides mainly consisting of the (TiCl ₄ -FeCl ₃ ) system, since FeCl ₃ has a melting point of 300°C and a boiling point of 317°C, TiCl ₄ is first taken out of the system and then separated. , then FeCl ₃ for NbCl ₅ , _{ZrCl 4} and FeCl ₃ (melting point: 672℃, boiling point: 1024
℃ (very low vapor pressure), each component was separated and recovered. Example 2 The anatase ore shown in Table 1 was granulated into pellets in the same manner as in Example 1. The above granules were then heated in a plasma arc furnace for 2000 min.
℃ for 0.5 hours to obtain a reduced carbonized product. The product was formed in a molten state with distinct layers of an oxide slag phase, a carbide phase (forming a solid phase), and a metallic iron phase, and each layer was separated by mechanical peeling after cooling. The weight ratio of each of these layers is approximately 1:
The ratio was 4:5, and the composition was as shown in Tables 5 to 7.

【table】

【table】

[Table] Next, after removing the metallic iron phase and the oxide phase (slag phase), the carbide phase was treated in the same manner as the low-temperature chlorination after iron removal in Example 1 to obtain a mixed chloride solution, and then fractionated. TiCl ₄ , NbCl ₅ and ZrCl ₄ were separated and recovered. The oxide slag phase shown in Table 7 is Ce
and used as a raw material for La. The recovery rate of the metal components as each chloride was 98% or higher in all cases because the reaction proceeded rapidly in the molten state in the reduction/carbonization step. Effects of the Invention As explained above, the method of the present invention differs from the conventional titanium ore smelting method in that when anatase ore is processed, TiO ₂ in the ore is first converted into TiC. It is characterized by making the chloride recovery process extremely easy and promoting the reduction and carbonization of TiO ₂ by the molten iron generated from Fe ₂ O ₃ that coexists with TiO _2. As a result, high-grade titanium compounds are produced as well. Other valuable components such as Nb and Zr can be recovered with high yield. The method of the present invention also provides a method for concentrating rare metal components such as Ce and La contained in ores. As mentioned above, although this specification describes anatase ore, those skilled in the art will easily understand that the method of the present invention can also be used for other titanite ores containing valuable components.

[Brief explanation of drawings]

Both FIG. 1 and FIG. 2 are process system diagrams suitable for carrying out the present invention. This is the case when the process is carried out in a state of melt reduction. Figure 3 shows TiO ₂ single and (TiO ₂ +
FIG. 3 is a diagram showing differences in reduction rates in reduction experiments of Fe ₂ O ₃ ). FIG. 4 is a scanning electron micrograph (a) showing the particle structure of the reduction/carbonization product at 1300° C. and an explanatory diagram (b) thereof. FIG. 5 is a scanning electron micrograph (a) showing the particle structure of the reduction/carbonization product at 1100° C. and an explanatory diagram (b) thereof.

Claims (1)

[Claims] 1. A smelting method for extracting a titanium raw material suitable for manufacturing titanium metal or titanium oxide using the chlorine method from titanium ore, and also for separating and recovering valuable components contained in the ore. (a) Add a predetermined amount of carbonaceous material to titanium ore and mix thoroughly; (b) Reduce and carbonize the mixture at a temperature below its melting temperature to form a carbide phase, a metallic iron phase, and mainly Ti, (c) After cracking the product, the product is subjected to low-temperature chlorination treatment to form a mixed chloride mainly consisting of TiCl ₄ and FeCl ₃ and chloride residue. Alternatively, the magnetic particles are removed by magnetic separation and the non-magnetic substances are collected, and the non-magnetic substances are leached with acid to remove iron and the leaching residue is treated with low temperature chlorination to produce chlorides mainly consisting of _TiCl (d) separating the mixed chloride or the chloride into TiCl ₄ , FeCl ₃ , NbCl ₅ and ZrCl ₄ by a fractional distillation method; (e) separating the chloride residue into Ce and La; used as raw material for extraction of
A titanium ore smelting method characterized by comprising various steps. 2 The carbonaceous material mixed with titanium ore is coke,
At least one of graphite and charcoal,
Its content is TiO ₂ and Fe ₂ O ₃ contained in titanium ore.
2. The method of claim 1, wherein the amount of TiC is 1.2 to 1.5 times that required to reduce TiC and metallic iron, respectively. 3 The reduction and carbonization are performed using a rotary kiln.
A method according to claim 1, which is carried out at a temperature of 1200-1300<0>C. 4. The method of claim 1, wherein the magnetic separation process is performed in a magnetic field of 500 to 1500 Gauss. 5 The low-temperature chlorination treatment is carried out at 300°C using chlorine gas.
2. A method according to claim 1, which is carried out at temperatures in the vicinity. 6. A smelting method for extracting titanium raw material suitable for the production of metallic titanium or chlorine-method titanium oxide from titanium ore, as well as separating and recovering valuable components contained in the ore: (a) Titanium (b) The mixture is reduced and carbonized at a temperature higher than its melting temperature to form a TiC phase, a metallic iron phase, and mainly
(c) The product is mechanically exfoliated to form a carbide phase,
The metallic iron phase and the oxide phase are separated, and (d) the carbide phase is subjected to a low-temperature chlorination treatment to mainly
(e) The chloride is separated into TiCl ₄ and chloride residue by fractional _distillation .
A method for smelting titanium ore, comprising the steps of separating NbCl ₅ and ZrCl ₄ , respectively, and (f) using the chloride residue as a raw material for extracting Ce and La. 7 The carbonaceous material mixed with titanium ore is coke,
At least one of graphite and charcoal,
Its content is TiO ₂ and Fe ₂ O ₃ contained in titanium ore.
7. The method of claim 6, wherein the amount of TiC is 1.2 to 1.5 times that required to reduce TiC to TiC and metallic iron, respectively. 8 The above reduction and carbonization is carried out at 2000°C using a normal arc furnace, plasma arc furnace or argon arc furnace.
7. The method according to claim 6, which is carried out at a temperature above. 9 The low-temperature chlorination treatment is carried out at 300°C using chlorine gas.
7. A method according to claim 6, carried out at temperatures in the vicinity.