TW200538397A - Production of titania - Google Patents

Abstract

A process for producing titania from a solid, iron-containing titaniferous material (such as ilmenite) is disclosed. The process includes a first step of treating iron-containing titaniferous material under conditions that reduce ferric ions to ferrous ions in the titaniferous material. Thereafter the process include steps of leaching treated titaniferous material and forming a leach liquor that includes an acidic solution of titanyl sulfate and iron sulfate and recovering titania from the leach liquor.

Description

• 200538397 IX. Description of the invention: [Sun and Moon Cooler]-. Field of invention • The present invention relates to a method for manufacturing titanium dioxide from a titanium-containing material. The term is used herein to denote any titanium-containing material, including by way of example ore, ore concentrate, and titanium-containing slag. • The present invention relates in particular to a method for producing titanium dioxide 10 from a solid titanium-containing material, which method is commonly referred to as the sulfate method. It should be understood that the term "sulfuric acid" method here refers to a method for manufacturing titanium dioxide from a titanium-containing material, which includes processing a solid feed material, and at least substantially dissolving the feed material into a solution, and subsequently recovering titanium dioxide from the solution. 15 The applicant conducted research and development work on the sulfate method. The results of the study yielded two options for the sulfate method. ® One method option is described in the international application PCT / AU03 / 01386, and the other method option is described in the international application PCT / AU22004 / 001421. Both method options include the following steps: 20 (a) leaching a solution containing sulfuric acid, leaching a solid iron-containing titanium-containing material (such as ilmenite), and generating a leachate that includes titanium oxysulfate (TiOS 〇4) and an acidic solution of iron sulfate (FeS〇4); (b) separating titanium oxysulfate from the filtrate, for example, by solvent extraction as described in the international application PCT / AU03 / 01386, or as in international application 5 200538397 PCT / AU20043 / 001421 is separated by precipitation; and (c) the research and development of titanium dioxide recovery from titanium oxysulfate is included in 400-750 g / l wort filter sulfate. The research work involved the addition of iron in the form of iron filings during step (a) of the filtration step. 5 The main advantage of adding iron is to accelerate the filtration rate. The disadvantages of adding iron include increasing the content of iron sulfate as a by-product, and increasing the complexity of the process (so the factory needs equipment to handle iron filings, as well as the IL gas that escapes as a result of adding iron). In addition, iron filings are currently not expensive, but the additional operating costs of the booster process. In addition, the rate is that even if iron is added, it is still necessary to grind ilmenite before the leaching step to improve the leaching rate. The applicant further carried out research and development work and found that the leaching rate can be achieved in the leaching step. The iron leaching rate achieved by the addition of iron filings was achieved by reducing the iron ions in the reducible ilmenite before the filtration step. Treatment of ilmenite under ferrous ion conditions. Conditions include contact of the titanium-containing material with a reducing gas. The titanium 15 iron ore processing step avoids or at least minimizes the addition of iron filings during the delivery step.

t Description; J Summary of the invention Thus, the present invention provides a method for manufacturing titanium dioxide from iron ore. The 111-body iron-containing titanium-containing material (such as the delta method) includes the following steps: The titanium body contacts the titanium-containing titanium after the treatment process. It is called the leaching solution of the acid solution of acid and oxygen reduction and 20 200538397 iron sulfate; (c) recovering titanium dioxide from the filtrate. Better; step ⑷ is included in obtaining ferrous ions to become the main form of iron in titanium-containing materials. Titanium-containing materials are processed under the conditions. 10 15 "Main"-the word must be understood here means that the ferrous ion content is part A of the total iron in the core material. It is expressed by the actual content of ferrous ions in the processed material 'This means that the ferrous ion system accounts for the iron content of the treated material to ⑽% and typically at least a weight ratio. As far as the ferrous ion content in the processing step ⑷ is increased, the content of the ferrous ion containing the material is increased. Iron 2 is better than at least the ferrous ion content of the titanium-containing material before processing step 处理. Step ⑷ is included in conditions that will not cause the formation of rutile: processing titanium-containing materials, rutile in the step Under the conditions, it is not possible to respond to 0. Step ⑷ includes processing titanium-containing materials under the following conditions, so = no metal ions are generated in this step 'or a selected relatively small amount of metal ions is generated in this step. Appropriate processing equipment such as a fluidized bed or kiln. Fortunately, step (i) includes processing the titanium-containing material via contacting the titanium-containing material with a reducing gas in a first-rate fluidized bed. • • Related conditions for step (i) include, for example, selection (i) The composition of the reducing gas, the temperature of the reducing gas, and the contact time between the tritium reducing gas and the thorium-containing material. Carbon monoxide and its reducing gas may be any kind of gas such as a gas gas 200538397 mixture. The preferred 'reducing gas is (a ) A mixture of hydrogen and / or carbon monoxide and / or oxane with (b) another suitable gas such as an inert gas and / or carbon dioxide. Preferably the inert gas is nitrogen. 5 In the case where the reducing gas contains hydrogen and the inert gas contains nitrogen In this case, the preferred hydrogen system accounts for up to 25% of the reducing gas and more preferably a volume ratio of 3-25 / ❶. In the case where the reducing gas contains hydrogen, the temperature of the reducing gas is preferred. Below 70 ° C to avoid substantial formation of rutile, rutile cannot be leached under the conditions of leaching step (b). 10 Under the conditions where the reducing gas contains hydrogen, the preferred reducing gas temperature is 450-550. In the case where the reducing gas contains carbon monoxide and the other gas contains carbon dioxide, it is preferable that carbon monoxide accounts for up to 60% and more preferably 30-60% by volume of the reducing gas. 15 The reducing gas contains carbon monoxide and the inert gas contains nitrogen In this case, the temperature of the reducing gas is preferably lower than 700 t, and more preferably lower than 65 ° C. In the case where the reducing gas contains carbon monoxide and the inert gas contains nitrogen, a particularly preferred gas temperature is 600 ° C. The average contact time between Chevrolet material and reducing gas is less than 120 minutes, and 20 is more preferably 20-120 minutes. Steps (b) and (c) can be as described in the international application pCT / AU03 / 01386 and the international application PCT / AU2004 / 001421. In particular, the leaching step (b) includes multiple leaching steps, which involve the first step of leaching the titanium-containing material with the leaching solution and generating a process solution including an acidic solution of titanyl sulfate 200538397; With the residual solid phase; (i) using the leachate in the leaching followed by the leaching step, and producing another process solution including an acidic solution of titanyl sulfate and iron sulfate; or separating the process solution from the residual solid phase ; And (v) supplying the process solution obtained from the separation to 5 first leaching steps, and / or mixing the process solution obtained from the separation and the process solution obtained from the first leaching step for subsequent treatment in the reduction step (c). Preferably, leaching step (b) includes selecting and / or controlling leaching conditions to avoid undesired amounts of premature hydrolysis and to avoid undesired amounts of premature precipitation. 10 is typically at 95. (: When operating at a leaching temperature in the boiling point range, the acid concentration in the leaching step (b) must be at least 350 g / L sulfuric acid throughout the leaching step to avoid premature hydrolysis. In addition, typically, at 95 ° C When operating at the leaching temperature in the boiling point range, the acid concentration at the end of the leaching step (b) must be less than 450 g / l, so as to avoid unexpected precipitation of titanium oxysulfate in an unexpected amount. At the beginning of the leaching step (b) The acid concentration can be as high as any of the aforementioned desired concentrations, typically as high as 700 g / l. Specifically, step (C) recovers titanium dioxide by filtration and liquid containing the following steps: (i) separating iron sulfate from the leachate, (ii) After or before step 20, titanium oxysulfate is separated from the leachate, and (iii) titanium dioxide is recovered from the titanium oxysulfate. More specifically, step (ii) separating titanium oxysulfate from the leachate includes extracting sulfuric acid with the solvent from the leachate. Oxytitanium, as described in the international application PCT / AU03 / 01386. 9 200538397 Another possible option (but not the only) Step (ii) Separation of titanyl sulfate from the leachate contains precipitation of titanyl sulfate from the leachate, as in the international application Case PCT / AU2004 / 001421. The disclosures of International Application PCT / AU03 / 01386 and International Application 5 PCT / AU2004 / 001421 are incorporated herein by cross-reference. Steps (b) and (c) are not limited to the international application pCT / Au〇3 / 〇 The steps described in 1386 and international application PCT / AU2004 / 001421. For example, the 'leaching step (b) can be according to the standard sulfate method, which includes a two-stage step, the first stage involves obtaining from solid sulfuric acid with concentrated sulfuric acid obtained from The pre-treated titanium-containing material of step 10 (a); and the second stage involves dissolving the sulfated product in water / dilute acid, and generating an acidic solution of titanium oxysulfate and iron sulfate. Related processing by the applicant Focus on research and development of iron ore. Focus is on the use of hydrogen and carbon monoxide. Implementation Mode 15 Detailed description of the preferred embodiment The following description refers to the research and development work carried out by the applicant's Xincheng Technology Center. A comprehensive review of experimental parameters The first set of processing experiments involving hydrogen-containing reducing gases was performed at the Benup ilmenite. Details of the experiments performed at the Binan ilmenite extract are discussed here. Mine experiment For the prospective results obtained, a second batch of processing experiments was performed using a batch of Stradbroke ilmenite. These experiments will be discussed later. 20 200538397 Cruzor (trade name) ) Ilmenite carries out another set of experiments including a reducing gas containing carbon monoxide. These experiments will be discussed later. • Schablo's ilmenite experiment performed on the first batch of Schabro's ilmenite Note the effects of three variables in ilmenite treatment in focus set 5. These variables are ...

(a) Reducing gas temperature-450 ° C and 550 ° C (b) Gas composition-10% H2KN2 and 20% H2 in N2; and (c) Reduction time-45 minutes and 90 minutes • In the second batch of historical investigations In the experiments conducted by Buloh ilmenite, 10 points of attention were focused on verifying and processing the results of the first batch of Shichaluo ilmenite, and generating comparative data to provide a criterion for the evaluation results. -. Particle size of feed material Table 1 lists the particle size distribution of the first batch of Shichabulo ilmenite. 15 Table 1. Screening data of the first batch of Shichabulo ilmenite size (mm) Weight (g)%% Pass 1 0 0.000 100.000 0.5 0 0.000 100.000 0.425 0.1 0.023 99.977 0.3 0.8 0.187 99.790 0.25 3.7 0.865 98.925 0.18 43.4 10.143 88.782 0.125 172.8 40.383 48.399 0.109 85.9 20.075 28.324 0.09 88.4 20.659 7.665 0.063 32.4 7.572 0.093 0.053 0.2 0.047 0.047 0.038 0.1 0.023 0.023 Total: 219.2 100 Table 2 lists the particle size distribution of the first batch of Shichabulo ilmenite. 11 200538397 Table 2. Screening data of Shichabulo ilmenite in the second batch Size (mm) Weight (g)%% Pass 1 0 0.000 100.000 0.5 0 0.000 100.000 0.425 0 0.000 100.00 0.355 0.2 0.044 99.956 0.3 0.7 0.156 99.800 0.25 4.5 1.001 98.799 0.18 43.9 9.763 89.073 0.125 166.6 37.047 51.990 0.106 79.9 17.678 34.312 0.09 105.3 23.416 10.896 0.063 47.3 10.518 0.378 0.053 1.2 0.267 0.111 0.038 0.4 0.089 0.022 -0.038 0.1 0.022 0.000 Total: 449.7 100

The first and second batches of Shichabulo ilmenite had similar particle size distributions, with smaller particle sizes than Binan ilmenite. Especially as the upper dimension is smaller, but the lower dimension is the same as that of Binan Ilmenite. Thermogravimetric Analysis Device Test The effect of using the reducing gas to treat the first batch of Schabro ilmenite in accordance with the present invention was first evaluated by a thermogravimetric analysis device ("TGA"). The full size 10 components of the first batch of Shichabulo ilmenite listed in Table 1 above were selected for the TGA experiment, because even the smallest component is large enough to withstand the terminal velocity of 12 l / min airflow. In addition, the use of "as accepted" size components also has the effect of further reducing the size through screening or crushing when manufacturing at the Plaza or on a factory scale. 15 Completed 8 experiments at 10 grams of the first batch of Schambro's ilmenite test. The experimental evaluation compares the effects of the three variables of the gas composition, temperature, and time described above. The effect of the experimental process on the weight loss of the sample was monitored experimentally. The variable matrix is listed in Table 3. Table 3. Variable matrix of TGA test Temperature Time Gas composition Low 450 ° C 45 10% H2 at n2 1¾ 550 ° C 90 20% H2 at N2

A summary of the experimental conditions and weight loss during the TGA test process is shown in Table 4. Table 4. Summary of TGA test results. Test temperature gas time weight loss% STR-IR0-L1 n / an / an / an / a STR-IR1-L1 450 10% H2 at n2 45 1.35 STR-IR2-L1 450 io% h2 at n2 90 1.46 STR-IR3-L1 550 io% h2 at n2 45 1.63 STR-IR4-L1 550 io% h2 at n2 90 1.74 STR-IR5-L1 450 20% H2 at N2 45 * 1.37 STR-IR6-L1 450 20% H2 at N2 90 1.45 STR-IR7-L1 550 20% H2 at N2 45 1.68 STR-IR8-L1 550 20% H2 at N2 90 2.04 TGA experimental results indicate that the processing steps can partially reduce ilmenite but cannot Ilmenite is completely reduced, in other words it cannot be reduced to the point where 100% metallic iron is produced. An example of the results in this regard is shown in Figure 1. Figure 1 shows that there was substantial weight loss 20 minutes before the experiment. Subsequently, the weight loss was a constant and fairly shallow gradient with respect to the test stop time. The weight loss of the constant gradient is consistent with the expected reduction of iron ions to ferrous ions. If the reduction has been completed, in other words, 100% of the metal ions are generated, the weight loss mapping is expected to be plateaued at a low level. Repeat the trend of Figure 1 for other tests. After the ilmenite test, the ilmenite was removed by TGA and then leached at 431 g / l sulfuric acid at 100 ° C or just below 100 ° C (on the same day). The leaching phase lasted a total of 5 hours. The solid and liquid are separated by filtration, and the filtrate is tested for free acid and titanium. Table 5 summarizes the extraction of titanium from ilmenite and the acids used in the experiments. Table 5. Extraction and acid consumption results 1 Original conditions I Leaching results Test temperature Gas time Weight loss Extraction acid consumption STR-IR0-L1 n / an / an / an / a 5.25 43.11 STR-IR1-L1 450 1〇 % Η2 at N2 45 1.35 6.44 41.97 STR-IR2-L1 450 i〇% h2 at n2 90 1.46 22.20 28.33 STR-IR3-L1 550 io% h2 at n2 45 1.63 30.84 22.62 STR-IR4-L1 550 io% h2 at n2 90 1.74 35.00 18.79 STR-IR5-L1 450 20% H2KN2 45 1.37 27.21 18.07 STR-IR6-L1 450 20% H2 at N2 90 1.45 32.19 16.94 STR-IR8-L1 550 20% H2 at N2 90 2.04 36.33 20.42 STR-IR13 -L1 550 20% H2 at N2 45 1.66 48.87 15.80 The extraction system is based on the weight obtained from the solid phase at the beginning of the experiment, and the weight of titanium present in the liquid phase after filtration is used to determine the degree of extraction. Sample STR-IR13-L1 is a repetition of sample STR-IR7-L1 (55 ° C, 20 15 ° CH2 for 45 minutes at N2), because the original result is the result of sample STR-IR7-L1 The reason is much lower than expected. Results for sample STR-IR7-L1 are not shown here. The original experiment found two errors, that is, the sample was hotter than expected when it was removed from the TGA (which may cause re-oxidation); and its 14 200538397 'significant reduction in the height of the water bath due to the poor seal between the water and the water during the filtration process' .

See ifbt-TGAMA in the TGA test. The results of leaching ilmenite treated according to the present invention show that 5 is the tested variable. (A) Extending the time or increasing the hydrogen concentration in the test range can improve the leaching extraction of ilmenite. Titanium '(b) The combination of the two variables did not significantly improve the extraction, and in all cases Φ (c), increasing the temperature in the test range can improve the extraction. 10 Treated material reduction unit test and subsequent leaching test The effects of the first batch of treatments according to the present invention-Schachbro ilmenite were also evaluated in a thermal reduction unit (HRR). HRR is a tube furnace, which contains a tube running through the center of the Kanthal split furnace. The tube furnace has three main sections. The upper section has a cyclone to slow down and remove particles from the gas phase. The impregnated feet return these solids to the bed. The sample section has a perforated plate that allows the solid bed to be fluidized by the reactive gas stream. Trials • Sample sizes usually weigh about 500 grams. The lower section below the specimen is filled with stainless steel shavings. This zone is designed as a heat exchanger to rapidly heat the reaction gas to the required reaction temperature. The difference between 20 HRR and TGA is that the entire sample is uniformly exposed to a stable reactive gas flow. The fluidized bed avoids weight transfer effects in the later stages of the TGA test. Result 'The comparison between TGA test and HRR test is difficult because the time required for HRR to reach a certain reduction point is shorter than the time required for TGA. 500 g of the first batch of non-milled schablo ilmenite at 20% private 15 200538397 at N2 at 550 C at HRR and processed according to the invention for 90 minutes. At the end of the 90-minute treatment period, the treated sample was cooled to peach under nitrogen, removed, and then filtered on the same day for 2 hours in sulfuric acid in a 2-liter reactor. The acid concentration was maintained at 400 g / l. The reaction flask was maintained at 110. 〇Temperature. The solid 5 loading at the beginning of leaching was 400 g / l. '' Titanium and iron dissolution rates exceed any other bench test results made by the applicant to date. The initial reaction rate caused the acid concentration to drop below the target acidity. The final solution contained 49 g / l of titanium, and a 'exceeded the titanium concentration of the solution tested almost completely up to the end of the month in terms of solid loading, time, and acid concentration. The titanium extracted from 10 solids was 34% (42/0 when sampling adjustment was performed). Compare the performance test-882 "testing, mouth dumping and running test, to confirm the previous results of the first batch of Shichabulo ilmenite treatment, and to compare the results of the treatment with other processing options. 15 20 500 g of the second batch of Shichabulo titanium samples were dirty, and added to the WC for a few minutes. At the end of the cycle time, the processed% was cooled to 4 generations under nitrogen and removed. Sulfuric acid was removed with a gram sample in a 2 liter reaction bottle for 5 hours. The reaction was held at U (rc temperature. The acid concentration was maintained at 45 g / L. The solid loading at the beginning of leaching was 50 g / L. As accepted in the form of 50 grams, Chanchabli iron ore, and the second batch of Shichabulo ilmenite samples in the form of grinding are also in the seam under the conditions described in the previous paragraph. In the case of all cases, add the M rod to the reaction flask. And the analysis and determination are carried out on the regular sampling of the leachate during the 5 hour experiment. 16 • 200538397 Mine extraction of titanium oxide to m The results are shown in Figure 2. Titanium is shown in the leachate. The titanium dioxide based on the second batch of Schabro The inventive treatment and subsequent leaching resulted in: (a) comparable results obtained using ground ilmenite; and (b) significantly better than unground ilmenite in terms of final recovery and extraction rate. 500 g of Kuzeite ilmenite sample was heated to the target temperature in the fluidized bed reactor when fluidized and reacted, and the nitrogen atmosphere was used to reduce the gas (C0, c0 2 2 ”H4, and After the specified time, the reducing gas was replaced with nitrogen to allow the reactor to cool. The product obtained from the reactor was immediately leached at 45 ° C at 45G g / L sulfuric acid for 48 hours. At special & interval pure analysis, To reduce the rate and extraction. 15

The reduction gas selected for the Kuzhinqin iron ore experiment is carbon dioxide. The results are shown in Figures 3 and 4. Fig. 3 is a graph of the reduction rate (%) of titanium obtained in experiments with different samples under different temperature conditions versus the drain time (hours). The purpose of this figure is to reduce the original temperature to the Yingxiang extraction rate of 20 times.

J ^ AX) TOO ~ 60〇 Too Figure 3 shows the titanium extraction at _〇c. The leaching time is the best. 17 200538397 In particular, Figure 3 shows that when leaching the sample reduced at 50CTC and 700 ° C, the titanium extraction rate is significantly lower than that of the reduced sample at 600 ° C. Figure 4 is a graph of the titanium extraction rate (%) versus the leaching time (hours) of the four samples at different partial pressures of CO and reducing gas. The figure shows the effect of the partial pressure of CO on the titanium extraction rate. Reducing gas temperature (° c) PP CO = 0.6 · ~ 600 ^ PP CO = 0.45 600 ~ " PP CO = 0.3 ~ 600 ~ Blank group-only N2 600, reducing sample when CO partial pressure of reducing gas = 0.6 Can achieve the highest extraction rate. 10 15

Hi # The foregoing experimental results indicate that the treatment of ilmenite according to the present invention is comparable to other options for accelerating the leaching rate, and to compare the current grinding and subsequent use of the iron chip_lang-like option, and the lower acid consumption can achieve dioxin. High recovery rate. Many modifications may be made to the foregoing invention without departing from the spirit and scope of the invention. [Schematic simple ^ say ^ clear] Figure 1 is an example of TGA experimental results. Figure 2 is the result of periodic sampling and analysis of the filtrate from the titanium during the 5-hour experiment. Figure 3 is a plot of the reduction rate (%) versus the filtration time (hours) of the four samples under different temperature conditions. 20 200538397

Figure 4 is a graph of the titanium extraction rate (%) versus the leaching time (hours) of the four samples at different partial pressures of CO and reducing gas. [Explanation of Symbols of Main Components] (None) 19

Claims (1)

200538397 10. Scope of patent application: 1. A method of solid titanium-containing material containing iron, the method includes the following steps: Qin Tieshiguang) manufacturing iridium dioxide osmium under the iron parts of the reducible titanium-containing material, processing The iron-containing titanium-containing material is in contact with the reducing gas of ferrous ions; the conditions include the titanium-containing material and (b) the titanium-containing material after leaching treatment, and the formation of the acid solution of ferric sulfate. Titanium oxysulfate 10 15 20 (C) Recovering dioxin from the leachate. 2 According to the method in the scope of the patent application, ° ferrous ions become titanium-containing material A A⑷ is included in the available titanium-containing material. Under the condition of the main iron form 3. If the scope of application for patent No. 丨 or 2 will lead to the substantial formation of rutile: where step ⑷ is included in the condition that is not in the filtering step 滤 cannot be mastered 4. 如 as above Each term = ⑷ is included in the method under the following conditions, in which the step generates metal ions, or in the 料 2 material, so it is not an ion at this step. ^ Generate a selected relatively small amount of gold 5. The method according to any one of the foregoing patent claims, wherein step (a) contains a titanium-containing material. ^ Planted in first-class chemical bed contact for treatment 6. As described in the aforementioned patent application, the method described in item A, where the reducing gas can be any gas such as chlorine, carbon monoxide, and mixtures thereof. 20 200538397 7. A method as claimed in any one of the foregoing patent claims, wherein the reducing gas is (a) hydrogen and / or carbon monoxide and / or methane and (b) another suitable gas such as an inert gas and / or carbon dioxide mixture. 8. The method according to item 7 of the patent application, wherein the inert gas is nitrogen 5 gas. 9. The method according to any one of the foregoing claims, wherein in the case where the reducing gas contains hydrogen and the inert gas contains nitrogen, the hydrogen system accounts for up to 25% and more preferably 3-25% by volume of the reducing gas. 10. The method according to any one of the scope of the aforementioned patent application, wherein in the case where the reducing gas contains hydrogen, the temperature of the reducing gas is lower than 700 ° C to avoid substantial formation of rutile, and the rutile is subjected to a leaching step ( b) can not be filtered under the conditions. 11. The method according to any one of the foregoing claims, wherein the temperature of the reducing gas is 15 450-550 under the condition that the reducing gas contains hydrogen. . . 12. The method according to any one of the claims 1 to 8, wherein in the case where the reducing gas contains carbon monoxide and the other gas contains carbon dioxide, carbon monoxide accounts for up to 60% and more preferably 30-60% of the reducing gas. Volume ratio. 20 13. The method according to any one of claims 1 to 8 in the scope of patent application, wherein in the case where the reducing gas contains carbon monoxide and the inert gas contains nitrogen, the temperature of the reducing gas is lower than 700 ° C, and more preferably lower than 650. ° C. 14. The method according to any one of claims 1 to 8 in the scope of patent application, wherein in the case where the reducing gas contains carbon monoxide and the inert gas contains nitrogen, the temperature of the gas 21 200538397 is 600 ° C. 15. The method according to any one of the foregoing claims, wherein the average contact phase of the titanium-containing material with the reducing gas is in the step minutes, more preferably 20-120 minutes. XI Yu 12〇16. The method according to any one of the scope of the aforementioned patent application, wherein the step (b) above includes multiple leaching steps, which involves leaching of the 10th and 20th liquid leaching. The titanium-containing material, and a process solution including sulfuric acid, to separate the process solution from the residual solid phase, and to separate the residual solid phase from the leaching followed by the leaching step, and the raw spoon) to titanate and ferric sulfate Another process solution of the acidic solution includes the separation of the stone solution from the process solution and the residual solid phase; and the omega supply is divided into the first-leach step, and / or the process solution of the process solution obtained after the separation step is mixed and separated for subsequent reduction. Step π is the same as the aforementioned cap paste, which includes selecting and / or controlling leaching conditions to avoid premature hydrolysis of Feili 2 and premature sinking of non-expected quantities. 18. The method according to any one of the aforementioned patent application scopes, wherein when the temperature of the 4 o'clock temperature of C is operated, the acid of step (b) is filtered: the entire leaching step must be at least 35. G / L sulfuric acid to avoid over: 19. As described in the above M patent method, each of the methods of shooting 1, in which when operating at the temperature of 95 C of the monument range, the acid concentration at the end of step (b) must be low At 450 g / l, to avoid undesired amounts of oxygen sulphate sharpening 22 200538397 Early sanctuary. 20. A method as claimed in any one of the foregoing patent claims, wherein the acid concentration at the beginning of step (b) is less than 700 g / l. 21. The method according to any one of the preceding claims, wherein step (c) 5 recovering titanium dioxide from the leachate comprises the following steps: (i) separating the iron sulfate from the leachate, (ii) after or before step (i) , Separating titanyl sulfate from the leachate, and (iii) recovering titanium dioxide from titanyl sulfate. 22. The method of claim 21, wherein step (ii) separating the titanyl sulfate from the leachate B comprises extracting the titanyl sulfate with a solvent from the leachate. 10 23. The method of claim 21, wherein step (ii) separating the titanyl sulfate from the leachate comprises precipitating the titanyl sulfate from the leachate. * 24. The method according to any one of claims 1 to 15, wherein the leaching step (b) can be based on a standard sulfate method, which includes a two-stage step, and the first stage involves solid sulfurization with concentrated sulfuric acid. The pre-treated titanium-containing material from step (a); and the second stage involves dissolving the sulfated product in water / dilute acid and generating an acidic solution of titanium oxysulfate and iron sulfate. twenty three