阅读说明：本技术 富钛料的制备方法以及四氯化钛的制备方法 (Preparation method of titanium-rich material and preparation method of titanium tetrachloride ) 是由 和奔流 陈建立 肖莎莎 张坤 贺高峰 彭忠辉 豆君 陈树忠 张海涛 于 2021-11-01 设计创作，主要内容包括：本发明涉及冶金及化工技术领域,具体而言,涉及富钛料的制备方法以及四氯化钛的制备方法。富钛料的制备方法包括：将钛精矿和还原剂混合熔炼后得到的熔融钛渣与水淬液混合,进行水淬,得到水淬渣；将水淬渣进行酸浸,然后固液分离,得到酸浸钛渣；将酸浸钛渣依次进行氧化焙烧和还原焙烧,得到焙烧料,将焙烧料进行酸浸,然后固液分离,得到富钛料。采用水淬对熔融钛渣进行破碎,极速冷却能改变钛渣的物相结构,将钛渣中的黑钛石转变为金红石相,恶化钛的酸溶性,使杂质钙、铝等转化为酸溶性好的Ca-(3)Al-(2)O-(6),再经过酸浸、氧化及还原焙烧-酸浸进行除杂,能够获得CaO≤0.15wt.％且CaO+MgO≤1.5wt.％的优质富钛料。(The invention relates to the technical field of metallurgy and chemical industry, in particular to a preparation method of a titanium-rich material and a preparation method of titanium tetrachloride. The preparation method of the titanium-rich material comprises the following steps: mixing molten titanium slag obtained after mixing and smelting the titanium concentrate and the reducing agent with water quenching liquid, and performing water quenching to obtain water quenching slag; acid leaching the water-quenched slag, and then carrying out solid-liquid separation to obtain acid-leached titanium slag; and sequentially carrying out oxidizing roasting and reducing roasting on the acid-leached titanium slag to obtain a roasted material, carrying out acid leaching on the roasted material, and then carrying out solid-liquid separation to obtain a titanium-rich material. Crushing the molten titanium slag by water quenching, changing the phase structure of the titanium slag by extremely rapid cooling, converting the black titanium stone in the titanium slag into rutile phase, deteriorating the acid solubility of the titanium, and converting impurities such as calcium, aluminum and the like into Ca with good acid solubility 3 Al 2 O 6 Then acid leaching, oxidation and reduction roasting-acid leaching are carried out to remove impurities, so that high-quality enriched liquid with CaO being less than or equal to 0.15 wt.% and CaO + MgO being less than or equal to 1.5 wt.% can be obtainedAnd (3) titanium material.)

1. The preparation method of the titanium-rich material is characterized by comprising the following steps:

(a) mixing molten titanium slag obtained by mixing and smelting the titanium concentrate and the reducing agent with water quenching liquid, and performing water quenching to obtain water quenched slag;

(b) acid leaching the water-quenched slag, and then carrying out solid-liquid separation to obtain acid-leached titanium slag;

(c) sequentially carrying out oxidizing roasting and reducing roasting on the acid-leached titanium slag to obtain a roasted material, carrying out acid leaching on the roasted material, and then carrying out solid-liquid separation to obtain the titanium-rich material;

wherein the water quenching liquid comprises at least one of water, alkali solution and ferrous chloride solution;

the mass fraction of CaO in the titanium-rich material is less than or equal to 0.15 percent, and the sum of the mass fractions of CaO and MgO is less than or equal to 1.5 percent.

2. The method for preparing the titanium-rich material according to claim 1, wherein in the step (a), the mass fraction of CaO in the titanium concentrate is 0.3-2.5%, and the mass fraction of MgO in the titanium concentrate is 1-6%;

preferably, TiO in the molten titanium slag₂The mass fraction of the components is 75 percent～85％。

3. The method of claim 1, wherein in step (a), the reductant comprises at least one of anthracite, metallurgical coke, or petroleum coke;

preferably, the mass ratio of the titanium concentrate to the reducing agent is 1: 0.1-0.3.

4. The method according to claim 1, wherein in step (a), the alkali solution comprises at least one of a sodium hydroxide solution, a calcium hydroxide solution and a potassium hydroxide solution;

preferably, the pressure of the water quenching is 2-50 kg.f/cm²；

Preferably, the particle size of the water-quenched slag is 0.1-4 mm.

5. The method for preparing the titanium-rich material according to any one of claims 1 to 4, wherein in the step (b), the water-quenched slag is crushed and sieved to have a particle size of 20 to 160 meshes before the acid leaching;

preferably, the acid leaching temperature is 25-150 ℃, and the time is 0.2-36 h.

6. The method for preparing the titanium-rich material according to any one of claims 1 to 4, wherein in the step (b) and/or the step (c), the acid-leached acid solution comprises at least one of hydrochloric acid, sulfuric acid, nitric acid, acetic acid and hydrofluoric acid; preferably, the mass fraction of the acid solution is 5-30%;

preferably, in the step (b), the mass ratio of the acid solution to the water-quenched slag is 0.5-20: 1;

preferably, in the step (c), the mass ratio of the acid solution to the roasted material is 0.5-20: 1.

7. The method for preparing the titanium-rich material according to any one of claims 1 to 4, wherein in the step (c), the oxidizing roasting temperature is 600 to 1000 ℃ and the time is 0.2 to 4 hours.

8. The method for preparing the titanium-rich material according to any one of claims 1 to 4, wherein in the step (c), the temperature of the reduction roasting is 600 to 950 ℃, and the time is 0.5 to 5 hours;

preferably, the reductive calcination is performed in a reducing atmosphere.

9. The method for preparing the titanium-rich material according to any one of claims 1 to 4, wherein in the step (c), the acid leaching temperature is 60 to 170 ℃ and the time is 0.2 to 36 hours.

10. A method for producing titanium tetrachloride, comprising the method for producing a titanium-rich material according to any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of metallurgy and chemical industry, in particular to a preparation method of a titanium-rich material and a preparation method of titanium tetrachloride.

Background

Titanium white powder is considered as one of the best white pigments at present, and is widely applied to industries such as coatings, plastics, papermaking, printing ink, chemical fibers, rubber, cosmetics and the like. The industrial production method of the titanium dioxide comprises a sulfuric acid method and a chlorination method, and the sulfuric acid method has long production flow, poor product quality and easy pollution; and the titanium chloride white is environment-friendly. However, titanium white chloride has very strict requirements on raw materials and pursues high TiO₂The content of CaO and MgO impurities can generate chlorides with low melting point and high boiling point in the chlorination process, thereby deteriorating the fluidity of the bed layer of the boiling chlorination furnace.

At present, three industrial production methods of the titanium-rich material for large-scale boiling chlorination exist: the method comprises an electric furnace method, an acid leaching method and a reduction corrosion method, wherein the three methods have high requirements on raw materials and are basically high-quality placer resources with low impurity content. However, China is rich in ilmenite rock ore resources, and high-quality ilmenite placer ore resources are relatively few. Therefore, the utilization value of low-quality titanium resources is improved, and the processing of the low-quality titanium resources into high-quality titanium white chloride or titanium sponge raw materials is of great significance.

In view of the above, patent CN109338124A discloses a method for preparing chlorine by using high silicon-calcium-magnesium titanium concentrateThe method for dissolving the titanium-rich material obtains SiO by adopting flotation desilicication and impurity removal on titanium concentrate entering a furnace₂<1.5 percent of the low-silicon titanium concentrate is smelted in a furnace to obtain acid sludge. However, it causes the following problems in order to separate purer low-silicon titanium concentrate from high-silicon calcium magnesium titanium concentrate: the yield of concentrate (low silicon titano concentrate) is low, but SiO₂The grade of the titanium concentrate tailings can meet the requirement of titanium dioxide used by sulfuric acid method, or the yield of the concentrate is high, but the titanium concentrate tailings contain SiO₂The grade is too high to meet the requirement of producing the titanium dioxide by the sulfuric acid method. Therefore, the patent is due to the SiO in the low-silicon titanium concentrate₂The content is determined as<1.5% and limits its economy and practicality.

Patent CN111534706A discloses a method for preparing a titanium-rich material from Panxi titanium concentrate, which comprises the steps of titanium concentrate ore dressing, smelting, screening, roasting, alkaline leaching, acid leaching, calcining and the like, wherein CaO and SiO in the obtained product₂The content is lower.

However, both of the above patents relate to the secondary flotation and impurity removal of the titanium concentrate, which may aggravate the pulverization of the titanium concentrate, thereby causing great difficulty in the subsequent smelting of the concentrate in the furnace, and the feeding of the powder into the furnace may not only cause the reduction of the titanium yield, but also affect the stable operation of the electric furnace.

Patent CN106191428A discloses a method for preparing low-calcium magnesium titanium slag from Panzhihua titanium concentrate, which comprises subjecting Panzhihua titanium concentrate to ball milling, oxidation, acid leaching, selectively removing most of calcium and magnesium impurities, and reducing to obtain metal pellets with high reaction activity, thereby obtaining TiO₂The titanium-rich material with the content of more than 85 percent and lower calcium and magnesium content. However, the leaching of impurities in the titanium concentrate is promoted by ball milling and oxidation modification, and the industrialization is difficult to realize.

The methods all relate to electric furnace smelting, certain geographical limitation exists, and due to the relative confidentiality of large-scale electric furnace smelting technology and the relatively high investment cost of electric furnaces, research on direct upgrading of artificial rutile by titanium concentrate is necessary.

Patent CN111676379A discloses a method for preparing a chlorinated titanium-rich material from Panxi titanium concentrate, which is to add a certain amount of alkali metal salt into Panxi titanium concentrate or titanium slag obtained by smelting Panxi titanium concentrate for oxidizing roasting, then selectively chloridize the roasted material, and then screen, wash with water, filter, dry, and calcine. However, this method has the following disadvantages: the introduction of alkali metal can destroy the phase structure of titanium concentrate or titanium slag to generate titanate, thereby improving the reaction activity of titanium; and more titanium is generated into titanium tetrachloride with poor quality in the chlorination process, so that the purification difficulty is high, and the overall titanium yield is low.

Patent CN110776003A discloses a method for preparing artificial rutile by using low-grade high-calcium magnesium ilmenite, and high-grade ilmenite and low-grade ilmenite are used as raw materials for generating the artificial rutile. However, the implementation of the patent has certain difficulties, which are mainly reflected in pseudobrookite Fe₂TiO₅The content is controlled, although the oxidation temperature is controlled to be 600-750 ℃, the generated Fe is inevitable₂O₃With TiO₂The reaction will generate Fe₂TiO₅Once Fe is produced₂TiO₅This iron fraction is difficult to leach, even with pressure leaching. In addition, the silicon content in the low-grade ilmenite cannot be effectively removed through acid leaching, and the product quality of the obtained titanium-rich material is not high; the granularity of the obtained titanium-rich material directly depends on the original granularity of the titanium concentrate, and the fine-grained titanium ore needs to be granulated or the granulation capacity of the obtained titanium-rich material product meets the requirement of a chlorination process.

Therefore, most of the fine-grade high-calcium magnesium titanium concentrate can not be directly upgraded into a qualified titanium white chloride raw material, and the problem of difficult utilization of the high-calcium magnesium titanium concentrate still exists.

In view of the above, the present invention is particularly proposed.

Disclosure of Invention

The first purpose of the invention is to provide a method for preparing a titanium-rich material, which comprises the steps of crushing molten titanium slag by adopting a water quenching process, changing the phase structure of the titanium slag by utilizing the characteristic of extremely-fast cooling, converting the black titanium stone in the titanium slag into a rutile phase, deteriorating the acid solubility of titanium, and converting impurities such as calcium, aluminum and the like into Ca with good acid solubility₃Al₂O₆Then removing impurities by acid leaching-oxidizing roasting-reducing roasting-acid leaching process, and obtaining the content of CaO less than or equal to 0.15 wt%And CaO + MgO accounts for less than or equal to 1.5 wt.% of the high-quality titanium-rich material. Solves the problems that the high-calcium magnesium titanium concentrate can not be directly prepared to obtain the qualified titanium white chloride raw material and the high-calcium magnesium titanium concentrate is difficult to utilize in the prior art.

The second purpose of the invention is to provide a method for preparing titanium tetrachloride, and the high-quality titanium-rich material which is prepared by adopting a specific method and has low impurity content and proper granularity can be directly used for producing titanium tetrachloride by a boiling chlorination method, thereby being beneficial to mass production.

In order to achieve the above purpose of the present invention, the following technical solutions are adopted:

the invention provides a preparation method of a titanium-rich material, which comprises the following steps:

(a) mixing molten titanium slag obtained by mixing and smelting the titanium concentrate and the reducing agent with water quenching liquid, and performing water quenching to obtain water quenched slag;

(b) acid leaching the water-quenched slag, and then carrying out solid-liquid separation to obtain acid-leached titanium slag;

(c) sequentially carrying out oxidizing roasting and reducing roasting on the acid-leached titanium slag to obtain a roasted material, carrying out acid leaching on the roasted material, and then carrying out solid-liquid separation to obtain the titanium-rich material;

wherein the water quenching liquid comprises at least one of water, alkali solution and ferrous chloride solution;

the mass fraction of CaO in the titanium-rich material is less than or equal to 0.15 percent, and the sum of the mass fractions of CaO and MgO is less than or equal to 1.5 percent.

Compared with the traditional mode of producing titanium slag by slowly cooling titanium slag, the preparation method of the titanium-rich material provided by the invention carries out water quenching on the molten titanium slag, the water quenching process is to shock and quench the high-temperature molten titanium slag by a large amount of high-pressure water quenching liquid, the high-temperature molten titanium slag can be exploded into small-particle water-quenched slag due to the dual effects of the high-pressure water quenching liquid impact and the cooling internal stress on the molten titanium slag, and the phase of the water-quenched slag can be changed due to the rapid cooling.

The invention mixes the titanium concentrate and the reducing agent for smelting, and the molten titanium slag obtained after smelting has the following main phases: titanium black stone, talcite, siliceous vitreous body, calcium is mainly present in the siliceous vitreous body. In the water quenching process, the black titanium stone can be rutile, but the titanium is not leached basically, the original size fraction can be kept, and the titanium yield is effectively ensured.

The invention can change the phase structure of the molten titanium slag through water quenching, and promote part of the black titanium stone in the titanium slag to be converted into rutile TiO type₂And contains a large amount of glass (glass means a solid matter which is not crystallized, is in an unstable state, and has high chemical activity). The main reasons why the water-quenched slag contains a large amount of glass are as follows: the high-temperature liquid molten titanium slag is rapidly cooled by high-pressure water, so that atoms or ions in the slag are not as good as to form regularly arranged crystal substances, and the slag is solidified to form glass.

After molten titanium slag is water quenched, the schorl in the titanium slag is converted into rutile phase, and impurities in the titanium slag such as calcium, aluminum and the like can be converted into Ca with good acid solubility₃Al₂O₆And the acid solubility of the titanium is deteriorated, most of calcium and aluminum in the titanium slag are dissociated from the silicate phase to form calcium-aluminum compounds, so that the acid solubility of impurity calcium is greatly improved, and the subsequent acid leaching and impurity removal are facilitated.

In the acid leaching process, acid-soluble glass such as Ca₃Al₂O₆The calcium and the aluminum react with acid liquor, the calcium and the aluminum are leached by an acid leaching method, the aim of obviously reducing the content of impurities such as calcium, aluminum and the like in the titanium slag can be realized under relatively mild acid leaching conditions, and meanwhile, the titanium loss can be reduced by avoiding the dissolution of titanium.

In addition, the invention adopts a water quenching process to crush the molten titanium slag, and the qualified grain size of the crushed titanium slag can reach more than 90 percent and is far higher than the qualified grain size of the traditional crushing. In addition, the titanium concentrate is processed into titanium slag, and then the titanium slag is smelted, water quenched and crushed to qualified granularity to prepare the titanium-rich material for boiling chlorination, so that the problem of product pulverization can be fundamentally solved.

By adopting the oxidation roasting and reduction roasting processes, because the rutile exists at the earlier stage, the oxidation roasting-reduction roasting is beneficial to the growth of the rutile, and the titanium dissolution in the subsequent acid leaching process is greatly inhibited. Meanwhile, because the water quenching and the acid leaching pretreatment (in the step (b)) are carried out in the earlier stage, the temperature range of the subsequent oxidation and reduction roasting is greatly reduced.

In conclusion, the invention utilizes the water quenching process to change the phase structure of the titanium slag and change impurities such as calcium, aluminum and the like into acid-soluble compounds; meanwhile, the acid leaching-oxidation-reduction-acid leaching process is adopted, so that the acid leaching rate of calcium is over 90 percent, and the prepared titanium-rich material product has low impurity content and proper granularity, and is more beneficial to producing titanium tetrachloride by a boiling chlorination method. In addition, the water quenching process also greatly shortens the period of cooling and crushing the titanium slag, reduces the temperature of subsequent oxidizing roasting and reducing roasting, saves time and reduces cost.

In some embodiments of the invention, the water quenching is performed in a granulation tower.

The preparation method of the titanium-rich material provided by the invention comprises the following steps of:

water quenching: part of the black titanium stone in the molten titanium slag is oxidized into rutile TiO₂Calcium, aluminium, etc. forming a glass, e.g. Ca₃Al₂O₆。

Acid leaching in step (b): the contents of calcium and aluminum in the titanium slag are reduced through acid liquor leaching, and the main chemical reactions are as follows: ca₃Al₂O₆+12H⁺＝3Ca²⁺+2Al³⁺+H₂O。

Step (c) oxidizing roasting and reducing roasting: the acid-leaching titanium slag is subjected to oxidation roasting and reduction roasting treatment, so that the structure of the titanium slag can be damaged, and a porous structure is formed, thereby being beneficial to subsequent acid leaching for removing impurities such as iron, magnesium and the like.

In addition, when the water quenching liquid is alkaline liquor, a part of silicon and aluminum in the titanium slag can react with the alkali to generate a substance which is easy to dissolve in water, so that impurity elements can be removed; when the ferrous chloride solution is selected, a part of soluble impurity elements such as iron, calcium, magnesium and the like in the titanium slag can be removed in a small amount because the ferrous chloride solution is acidic.

In some embodiments of the present invention, the acid leaching method may be any conventional acid leaching method, including but not limited to any one or more of heap leaching, column leaching, agitation leaching and pressure leaching.

The heap leaching is a method of spraying a heap with a leaching solution to selectively leach useful components from the ore during downward infiltration, and recovering the useful components from a pregnant solution flowing out of the bottom of the heap. The heap leaching method has simple process, less equipment and low energy consumption. Column leaching, refers to a leaching process performed in a plexiglass or plastic percolation column. Agitation leaching is a leaching process in which a ground material and a leaching agent are mixed in a mechanically agitated or air agitated open tank. Pressure leaching refers to a process of leaching elements from ores with acid or alkali solutions under elevated temperature and pressure conditions.

Preferably, in step (a), the mass fraction of CaO in the ilmenite concentrate is 0.3% to 2.5%, including but not limited to the point value of any one of 0.5%, 1.0%, 1.5%, 2.0%, 2.3% or the range value between any two.

Preferably, in the step (a), the mass fraction of MgO in the titanium concentrate is 1-6%; including but not limited to, a point value of any one of 2%, 3%, 4%, 5%, or a range value between any two.

The invention provides the titanium concentrate with the highest CaO and MgO contents for preparing the qualified boiling chlorination raw material-titanium-rich material, and the raw material has wide application range.

Preferably, TiO in the molten titanium slag₂Including but not limited to, a point value of any one of 77%, 79%, 80%, 81%, 83%, 84%, or a range value between any two, of 75% to 85%.

By controlling TiO in the molten titanium slag₂The content of (A) is in the range, which is beneficial to preparing the titanium-rich material with low impurity content and better quality.

Preferably, in step (a), the reductant comprises at least one of anthracite coal, metallurgical coke, or petroleum coke.

In some specific embodiments of the invention, the metallurgical coke comprises petcoke. The coke is a metallurgical coke defective product, has low cost, and is beneficial to reducing the cost of the titanium-rich material.

Preferably, the mass ratio of the titanium concentrate to the reducing agent is 1: 0.1-0.3, including but not limited to any one of the point values of 1:0.15, 1:0.2, 1:0.25, 1:0.28 or a range value between any two.

The reducing agent of the kind, the titanium concentrate and the reducing agent within the dosage ratio range are adopted, so that the content of impurities is reduced, and the quality of the titanium-rich material is improved.

Preferably, in step (a), the alkali solution in the water quench liquid comprises at least one of a sodium hydroxide solution, a calcium hydroxide solution and a potassium hydroxide solution.

Preferably, the pressure of the water quenching is 2-50 kg.f/cm²(ii) a Including but not limited to 5kg · f/cm²、10kg·f/cm²、15kg·f/cm²、20kg·f/cm²、25kg·f/cm²、30kg·f/cm²、35kg·f/cm²、40kg·f/cm²、45kg·f/cm²A point value of any one of them, or a range value between any two.

The water quenching adopts the pressure range, which is beneficial to controlling the impact force and the cooling internal stress of the water quenching liquid, so that the titanium black in the titanium slag is more converted into rutile phase, and the subsequent acid leaching and impurity removal are facilitated; meanwhile, the granularity of the water-quenched slag can be controlled conveniently.

Preferably, the particle size of the water-quenched slag is 0.1-4 mm, including but not limited to any one of 0.2mm, 0.4mm, 0.5mm, 0.8mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm, 3.5mm, 3.8mm or a range value between any two.

The granularity of the water quenching slag is influenced by the pressure and the flow of the water quenching liquid, and the larger the pressure of the high-pressure water is, the finer the granularity of the water quenching slag is. In some embodiments of the invention, the particle size of the water-quenched slag is controlled by controlling the pressure of the water-quenching liquid and controlling the particle size of the water-quenched slag.

Preferably, in the step (b), the water-quenched slag is crushed and sieved to have a particle size of 20-160 meshes before the acid leaching.

Preferably, the crushing comprises a conventional, random crushing method; the screening includes conventional, optionally screening methods.

In some embodiments of the invention, the method of crushing comprises at least one of crushing, chopping, fracking, milling, and impacting.

The invention adopts a water quenching process to crush the slag, and the qualified grain size of the crushed titanium slag can reach more than 90 percent and is far higher than the grain size qualified rate of the traditional crushing.

Meanwhile, the titanium concentrate is processed into titanium slag, the titanium slag is crushed to be qualified in granularity, and then the titanium-rich material for boiling chlorination is upgraded, so that the problem of product pulverization can be fundamentally solved.

Preferably, in step (a), the temperature of the melting is 1400 to 1700 ℃, including but not limited to the values of any one of 1450 ℃, 1500 ℃, 1550 ℃, 1600 ℃, 1650 ℃, 1680 ℃ or the range between any two.

Preferably, in step (b), the temperature of the acid leaching is 25 to 150 ℃, including but not limited to the point value of any one of 30 ℃, 35 ℃, 40 ℃, 50 ℃, 60 ℃, 70 ℃, 80 ℃, 90 ℃, 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 145 ℃ or the range value between any two;

preferably, in step (b), the acid leaching time is 0.2-36 h, including but not limited to any one of 0.5h, 1h, 2h, 5h, 10h, 15h, 20h, 25h, 30h, 33h, 35h or a range between any two.

The adoption of the acid leaching temperature and the acid leaching time is beneficial to improving the impurity removal efficiency.

Preferably, in step (b) and/or step (c), the acid-leached acid solution comprises at least one of hydrochloric acid, sulfuric acid, nitric acid, acetic acid and hydrofluoric acid;

preferably, the mass fraction of the acid solution is 5-30%; including but not limited to, a point value of any one of 6%, 8%, 10%, 12%, 15%, 17%, 19%, 22%, 25%, 27%, 29%, or a range value between any two.

Preferably, in the step (b), the mass ratio of the acid solution to the water-quenched slag is 0.5-20: 1, including but not limited to any one of 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 9:1, 10:1, 12:1, 14:1, 15:1, 17:1 and 19:1 or a range between any two.

Preferably, in step (c), the mass ratio of the acid solution to the calcine is 0.5 to 20:1, including but not limited to any one of 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 9:1, 10:1, 12:1, 14:1, 15:1, 17:1, 19:1, or a range therebetween.

The acid solution with the above kind, concentration and dosage is adopted, so that the impurity removal efficiency is further improved.

In some specific embodiments of the present invention, the hydrochloric acid is hydrochloric acid as a byproduct of titanium dioxide chlorination process, and the sulfuric acid is sulfuric acid as a byproduct of titanium dioxide sulfuric acid process.

In some specific embodiments of the invention, the second-stage acid leaching mother liquor is used as the acid for the first-stage acid leaching, that is, the mother liquor obtained after the solid-liquid separation after the acid leaching in the step (c) is recycled as the acid solution in the step (b) when the titanium-rich material is prepared next time, so that the complete utilization of the acid for the acid leaching can be realized, the subsequent acid reprocessing can be effectively avoided, and the secondary pollution can be avoided. Meanwhile, the two-stage acid leaching mother liquor is used as acid for the first-stage acid leaching, wherein certain Ca exists²⁺The metal ions can improve the activity of the second-stage leached acid, and are more beneficial to leaching impurities.

Preferably, in the step (c), the temperature of the oxidizing roasting is 600 to 1000 ℃, including but not limited to any one of 650 ℃, 700 ℃, 750 ℃, 800 ℃, 850 ℃, 900 ℃, 950 ℃ or a range value between any two.

In the invention, the aim of calcium removal is achieved by early-stage acid leaching, so the temperature of oxidizing roasting does not need to be too high; the lower oxidizing roasting temperature is favorable for saving energy and reducing cost.

Preferably, in the step (c), the time of the oxidizing roasting is 0.2 to 4 hours, including but not limited to the point value of any one of 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours or the range value between any two.

Preferably, in step (c), the temperature of the reduction roasting is 600 to 950 ℃, including but not limited to the point value of any one of 620 ℃, 650 ℃, 680 ℃, 700 ℃, 730 ℃, 780 ℃, 800 ℃, 820 ℃, 850 ℃, 880 ℃, 900 ℃, 925 ℃, 940 ℃ or the range value between any two.

In the invention, the aim of calcium removal is achieved by early-stage acid leaching, so the temperature of reduction roasting is not required to be too high; the adoption of lower reduction roasting temperature is beneficial to saving energy and reducing cost.

Preferably, in the step (c), the time of the reduction roasting is 0.5-5 h; including but not limited to, a point value of any one of 1h, 1.5h, 2h, 3h, 4h, or a range value between any two.

Preferably, the reductive calcination is performed in a reducing atmosphere.

More preferably, the gas of the reducing atmosphere comprises at least one of electric furnace gas, natural gas, hydrogen and carbon monoxide.

By adopting the oxidation roasting and reduction roasting processes, because the rutile exists at the earlier stage, the oxidation roasting-reduction roasting process is beneficial to the growth of the rutile, and the titanium dissolution in the subsequent acid leaching process is greatly inhibited.

Meanwhile, because the water quenching and the acid leaching pretreatment (step (b)) are carried out in the earlier stage, the temperature range of the subsequent oxidation and reduction roasting is greatly reduced, and the implementation difficulty is low.

Preferably, in step (c), the temperature of the acid leaching is 60 to 170 ℃, including but not limited to the point value of any one of 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃, 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃, 160 ℃ or the range value between any two; in the step (c), the acid leaching time is 0.2-36 h, including but not limited to any one of 0.5h, 1h, 2h, 5h, 10h, 15h, 20h, 25h, 30h, 33h and 35h or a range between any two.

The adoption of the acid leaching temperature and the acid leaching time is beneficial to high-efficiency impurity removal.

The invention also provides a preparation method of titanium tetrachloride, which comprises the preparation method of the titanium-rich material.

The titanium-rich material prepared by the specific preparation method has low impurity content and proper granularity, can be directly used for producing titanium tetrachloride by a boiling chlorination method, and is beneficial to mass production; solves the problem of difficult utilization of titanium concentrate with high calcium and magnesium contents.

Compared with the prior art, the invention has the beneficial effects that:

(1) the preparation method of the titanium-rich material provided by the invention changes the phase structure of the titanium slag by using a water quenching process, converts the schorl in the titanium slag into the rutile phase, and converts impurities such as calcium, aluminum and the like into Ca with good acid solubility₃Al₂O₆The method is beneficial to subsequent acid leaching and impurity removal, and the aim of remarkably reducing the content of impurities such as calcium, aluminum and the like in the titanium slag can be fulfilled under the relatively mild acid leaching condition; meanwhile, the acid solubility of the titanium is deteriorated, the titanium is not leached basically, and the titanium yield is effectively ensured.

(2) According to the preparation method of the titanium-rich material, the water quenching process is adopted, the qualified particle size ratio of the crushed titanium slag can reach more than 90%, the prepared titanium-rich material is proper in particle size, the period of cooling and crushing the titanium slag can be greatly shortened, the time can be saved, and the cost can be reduced.

(3) According to the preparation method of the titanium-rich material, the water-quenched slag is subjected to acid leaching, oxidizing roasting, reducing roasting and acid leaching processes to destroy the structure of the titanium slag, so that the titanium slag forms a porous structure, the acid leaching rate of calcium can reach over 90 percent, and the prepared titanium-rich material is low in impurity content and high in quality; meanwhile, the slag is subjected to water quenching and acid leaching, so that the temperature ranges of oxidation and reduction roasting are greatly reduced.

(4) The invention provides the titanium concentrate with the highest CaO and MgO contents for preparing the qualified boiling chlorination raw material, and the raw material has wide application range.

(5) The invention uses the second-stage acid leaching mother liquor as the first-stage acid leaching acid, can realize the complete utilization of the acid for acid leaching by recycling, effectively avoids the subsequent acid reprocessing, can also improve the activity of the second-stage acid leaching, and is more beneficial to the impurity leaching.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic flow chart of a method for preparing a titanium-rich material provided in example 5 of the present invention;

FIG. 2 is an XRD pattern of a conventional titanium slag provided in the experimental example of the present invention;

FIG. 3 is an SEM image of a conventional titanium slag provided in an experimental example of the present invention;

FIG. 4 is a photomicrograph of a conventional titanium slag provided in the experimental examples of the present invention;

FIG. 5 is an XRD pattern of water-quenched slag according to an experimental example of the present invention;

FIG. 6 is an SEM image of water-quenched slag provided in the experimental example of the present invention;

FIG. 7 is a microphotograph of water-granulated slag according to an example of the present invention.

Detailed Description

The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and the detailed description, but those skilled in the art will understand that the following described embodiments are some, not all, of the embodiments of the present invention, and are only used for illustrating the present invention, and should not be construed as limiting the scope of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

Example 1

The preparation method of the titanium-rich material provided by the embodiment comprises the following steps:

(1) adding titanium concentrate with CaO of 2.0% by mass and MgO of 4.0% by mass and coke breeze into a titanium slag electric furnace according to the mass ratio of 1:0.2, and smelting, wherein the smelting temperature is controlled to 1650 ℃, so as to obtain molten titanium slag;

(2) putting the molten titanium slag obtained in the step (1) into a granulation tower to be mixed with high-pressure water quenching liquid, performing water quenching and crushing to obtain water-quenched slag with the granularity of 0.1-4 mm, and then crushing and screening the water-quenched slag to control the granularity of 20-160 meshes; wherein the water quenching liquid is water with the pressure of 50 kg.f/cm²；

(3) Mixing 20% of hydrochloric acid by mass and the water-quenched slag with the granularity of 20-160 meshes obtained in the step (2) according to the mass ratio of 10:1, carrying out acid leaching reaction at 105 ℃, carrying out solid-liquid separation, washing and drying after reacting for 3 hours to obtain acid-leached titanium slag;

(4) oxidizing and roasting the acid-leached titanium slag obtained in the step (3) at 1000 ℃ for 1h to obtain oxidized and roasted titanium slag, and then reducing the oxidized and roasted titanium slag for 2h at 800 ℃ by using electric furnace gas to obtain a roasted material;

(5) and (3) mixing hydrochloric acid with the mass fraction of 16% with the roasted material obtained in the step (4) according to the mass ratio of 3:1, carrying out acid leaching reaction at 140 ℃, carrying out solid-liquid separation, washing and drying after reaction for 10 hours, and obtaining the titanium-rich material.

The compositions of the water-quenched slag and the titanium-rich material prepared in this example were determined as shown in table 1 below, where TFe means total iron content.

Table 1 composition (wt.%) of titanium-rich material obtained in example 1

Composition (I)	TiO2	TFe	SiO2	Al2O3	CaO	MgO	MnO
								Water-quenched slag	80.62	5.38	3.47	1.84	1.85	5.44	1.40
Titanium-rich material	91.86	1.70	3.29	1.20	0.12	1.20	0.63

Example 2

The preparation method of the titanium-rich material provided by the embodiment comprises the following steps:

(1) adding titanium concentrate with CaO of 0.5 mass percent and MgO of 6.0 mass percent and coke breeze into a titanium slag electric furnace according to the mass ratio of 1:0.2 for smelting, and controlling the smelting temperature to 1550 ℃ to obtain molten titanium slag;

(2) putting the molten titanium slag obtained in the step (1) into a granulation tower to be mixed with high-pressure water quenching liquid, performing water quenching and crushing to obtain water-quenched slag with the granularity of 0.1-4 mm, and crushing and screening the water-quenched slag to ensure that the granularity of the water-quenched slag is 0.1-4 mmControlling the grain size to be 20-160 meshes; wherein the water quenching liquid is water with the pressure of 35 kg.f/cm²；

(3) Mixing 5% by mass of hydrofluoric acid and the water-quenched slag with the granularity of 20-160 meshes obtained in the step (2) according to the mass ratio of 0.5:1, carrying out acid leaching reaction at 25 ℃, carrying out solid-liquid separation, washing and drying after reacting for 15 hours to obtain acid-leached titanium slag;

(4) oxidizing and roasting the acid-leached titanium slag obtained in the step (3) at 1000 ℃ for 1h to obtain oxidized and roasted titanium slag, and then reducing the oxidized and roasted titanium slag with carbon monoxide at 900 ℃ for 3h to obtain a roasted material;

(5) and (3) mixing hydrochloric acid with the mass fraction of 19% with the roasted material obtained in the step (4) according to the mass ratio of 2:1, carrying out acid leaching reaction at 150 ℃, reacting for 2.5h, and then carrying out solid-liquid separation, washing and drying to obtain the titanium-rich material.

The components of the titanium-rich material are shown in the following table 2, wherein TFe refers to the total iron content.

Table 2 composition (wt.%) of titanium-rich material obtained in example 2

TiO2	TFe	SiO2	Al2O3	CaO	MgO	MnO
							92.36	1.31	3.57	1.22	0.11	0.89	0.54

Example 3

The preparation method of the titanium-rich material provided by the embodiment comprises the following steps:

(1) adding titanium concentrate with CaO of 2.5 mass percent and MgO of 1.0 mass percent and coke breeze into a titanium slag electric furnace according to the mass ratio of 1:0.2 for smelting, and controlling the smelting temperature to 1450 ℃ to obtain molten titanium slag;

(2) putting the molten titanium slag obtained in the step (1) into a granulation tower to be mixed with high-pressure water quenching liquid, performing water quenching and crushing to obtain water-quenched slag with the granularity of 0.1-4 mm, and then crushing and screening the water-quenched slag to control the granularity of 20-160 meshes; wherein the water quenching liquid is ferrous chloride solution, and the pressure of the water quenching liquid is 10 kg.f/cm²；

(3) Mixing 16% of hydrochloric acid by mass and the water-quenched slag with the granularity of 20-160 meshes obtained in the step (2) according to the mass ratio of 1.5:1, carrying out acid leaching reaction at 140 ℃, carrying out solid-liquid separation, washing and drying after reacting for 0.5h to obtain acid-leached titanium slag;

(4) oxidizing and roasting the acid-leached titanium slag obtained in the step (3) at 700 ℃ for 4h to obtain oxidized and roasted titanium slag, and then reducing the oxidized and roasted titanium slag with hydrogen at 600 ℃ for 2h to obtain a roasted material;

(5) and (3) mixing 20% by mass of sulfuric acid with the roasted material obtained in the step (4) according to a mass ratio of 15:1, carrying out acid leaching reaction at 170 ℃, reacting for 3 hours, and then carrying out solid-liquid separation, washing and drying to obtain the titanium-rich material.

The components of the titanium-rich material are shown in the following table 3, wherein TFe refers to the total iron content.

Table 3 composition (wt.%) of titanium-rich material obtained in example 3

Example 4

The preparation method of the titanium-rich material provided by the embodiment comprises the following steps:

(1) adding titanium concentrate with CaO of 2.0 mass percent and MgO of 3.0 mass percent and coke breeze into a titanium slag electric furnace according to the mass ratio of 1:0.2 for smelting, and controlling the smelting temperature to 1550 ℃ to obtain molten titanium slag;

(2) putting the molten titanium slag obtained in the step (1) into a granulation tower to be mixed with high-pressure water quenching liquid, performing water quenching and crushing to obtain water-quenched slag with the granularity of 0.1-4 mm, and then crushing and screening the water-quenched slag to control the granularity of 20-160 meshes; wherein the water quenching liquid is water with the pressure of 15 kg.f/cm²；

(3) Mixing 15% by mass of acetic acid and the water-quenched slag with the granularity of 20-160 meshes obtained in the step (2) according to a mass ratio of 20:1, carrying out acid leaching reaction at 40 ℃, carrying out solid-liquid separation, washing and drying after reacting for 10 hours to obtain acid-leached titanium slag;

(4) oxidizing and roasting the acid-leached titanium slag obtained in the step (3) at 900 ℃ for 0.2h to obtain oxidized and roasted titanium slag, and then reducing the oxidized and roasted titanium slag for 0.5h at 800 ℃ by using a mixed gas of carbon monoxide and hydrogen to obtain a roasted material;

(5) and (3) mixing hydrochloric acid with the mass fraction of 20% with the roasted material obtained in the step (4) according to the mass ratio of 3:1, carrying out acid leaching reaction at 120 ℃, carrying out solid-liquid separation, washing and drying after reacting for 20 hours, and obtaining the titanium-rich material.

The composition of the titanium-rich material was determined as shown in table 4 below, where TFe refers to the total iron content.

Table 4 composition (wt.%) of titanium-rich material obtained in example 4

TiO2	TFe	SiO2	Al2O3	CaO	MgO	MnO
							93.28	0.90	3.39	1.26	0.11	0.70	0.36

Example 5

The preparation method of the titanium-rich material provided by the embodiment is shown in fig. 1, and specifically comprises the following steps:

(1) adding 1.5 mass percent of CaO and 2.0 mass percent of MgO into a titanium slag electric furnace according to the mass ratio of 1:0.3 for smelting, and controlling the smelting temperature to 1650 ℃ to obtain molten titanium slag and molten iron;

(2) putting the molten titanium slag obtained in the step (1) into a granulation tower to be mixed with high-pressure water quenching liquid, performing water quenching and crushing to obtain water-quenched slag with the granularity of 0.1-4 mm, and crushing and screening the water-quenched slag to ensure that the granularity of the water-quenched slag is 0.1-4 mmControlling the grain size to be 20-160 meshes; wherein the water quenching liquid is sodium hydroxide solution, and the pressure of the sodium hydroxide solution is 8 kg.f/cm²；

(3) Mixing 20% of hydrochloric acid in mass fraction with the water-quenched slag with the granularity of 20-160 meshes obtained in the step (2) according to a mass ratio of 4:1, carrying out acid leaching reaction at 90 ℃, carrying out solid-liquid separation after 4h of reaction to respectively obtain filter residue and mother liquor (the mass fraction of the hydrochloric acid is 18%), washing and drying the filter residue to obtain acid-leached titanium slag;

(4) oxidizing and roasting the acid-leached titanium slag obtained in the step (3) at 800 ℃ for 3h to obtain oxidized and roasted titanium slag, and then reducing the oxidized and roasted titanium slag for 1.0h at 950 ℃ by using a mixed gas of carbon monoxide and hydrogen to obtain a roasted material;

(5) and (3) mixing the mother liquor (hydrochloric acid mass fraction is 18%) obtained in the step (3) and the roasted material obtained in the step (4) according to the mass ratio of 3:1, carrying out acid leaching reaction at 130 ℃, carrying out solid-liquid separation, washing and drying after reacting for 2 hours, and obtaining the titanium-rich material.

The composition of the titanium-rich material was determined as shown in table 5 below, where TFe refers to the total iron content.

Table 5 composition (wt.%) of titanium-rich material obtained in example 5

TiO2	TFe	SiO2	Al2O3	CaO	MgO	MnO
							94.46	1.00	3.33	0.40	0.08	0.53	0.20

Example 6

The preparation method of the titanium-rich material provided by the embodiment comprises the following steps:

(1) substantially the same as in step (1) of example 5 except that the coke breeze was replaced with anthracite coal;

(2) substantially the same as in step (2) of example 5 except that the sodium hydroxide solution was replaced with a potassium hydroxide solution, and the pressure of the potassium hydroxide solution was 5 kg. f/cm²；

(3) Mixing 30% of nitric acid and the water-quenched slag with the granularity of 20-160 meshes obtained in the step (2) according to the mass ratio of 3:1, carrying out acid leaching reaction at 150 ℃, carrying out solid-liquid separation, washing and drying after reacting for 36 hours to obtain acid-leached titanium slag;

(4) oxidizing and roasting the acid-leached titanium slag obtained in the step (3) for 3h at 600 ℃ to obtain oxidized and roasted titanium slag, and then reducing the oxidized and roasted titanium slag for 3h at 600 ℃ by using a mixed gas of carbon monoxide and hydrogen to obtain a roasted material;

(5) and (3) mixing hydrochloric acid with the mass fraction of 25% with the roasted material obtained in the step (4) according to the mass ratio of 5:1, carrying out acid leaching reaction at 60 ℃, carrying out solid-liquid separation, washing and drying after reacting for 30 hours, and obtaining the titanium-rich material.

The composition of the titanium-rich material was determined as shown in table 6 below, where TFe refers to the total iron content.

Table 6 composition (wt.%) of titanium-rich material obtained in example 6

TiO2	TFe	SiO2	Al2O3	CaO	MgO	MnO
							93.40	1.60	3.32	0.60	0.14	0.80	0.14

Comparative example 1

The preparation method of the titanium-rich material provided by the comparative example is basically the same as the example, and the difference is that in the step (2), water quenching is not carried out, but the molten titanium slag is cooled, crushed and sieved, so that the traditional titanium slag with the granularity controlled to be 20-160 meshes is obtained.

The conventional titanium slag and the titanium-rich material prepared by the comparative example have the following compositions in Table 7, wherein TFe refers to the total iron content.

TABLE 7 composition (wt.%) of titanium-rich material obtained in comparative example 1

Composition (I)	TiO2	TFe	SiO2	Al2O3	CaO	MgO	MnO
								Traditional titanium slag	80.78	5.20	3.89	1.83	1.74	5.22	1.34
Titanium-rich material	90.23	2.17	4.28	1.13	0.88	1.17	0.14

It can be seen that the mass fraction of CaO in the titanium-rich material prepared by the preparation method provided by the invention is less than or equal to 0.15%, and the sum of the mass fractions of CaO and MgO is less than or equal to 1.5%. In addition, the content of magnesium oxide and the content of calcium oxide in the titanium-rich materials in the examples 1-5 are lower than those in the comparative example 1, and particularly, the content of calcium oxide is remarkably lower than that in the comparative example 1.

Experimental example 1

XRD and SEM tests were performed on the water-quenched slag obtained in example 1 and the conventional titanium slag obtained in comparative example 1, respectively, and micrographs thereof were taken, respectively, as shown in FIGS. 2 to 7 and tables 8 to 9.

Specifically, fig. 2 is an XRD pattern of the conventional titanium slag prepared in comparative example 1; FIG. 3 is an SEM photograph of a conventional titanium slag obtained in comparative example 1; FIG. 4 is a photomicrograph of a conventional titanium slag obtained in comparative example 1; FIG. 5 is an XRD pattern of the water-quenched slag obtained in example 1; FIG. 6 is an SEM photograph of water-quenched slag obtained in example 1; FIG. 7 is a microphotograph of the water-quenched slag obtained in example 1. Table 8 shows the results of elemental analysis of the conventional titanium slag SEM corresponding to FIG. 3, and Table 9 shows the results of elemental analysis of the water-quenched slag SEM corresponding to FIG. 6.

In FIG. 3, reference numerals 014, 015 and 018 are Al-Si-Ca glasses, and reference numerals 016 and 017 are titanium phases.

In FIG. 6, 001 and 002 are Al-Si-Ca glassy substances, and 003 is a titanium ore phase.

TABLE 8 elemental analysis results of electron microscope of conventional titanium slag obtained in comparative example 1

TABLE 9 elemental analysis results of electron microscope for water-quenched slag obtained in example 1

As can be seen from fig. 2 and 5, the XRD peak of the water-quenched slag was low, which indicates that the water-quenched slag contained a high content of vitreous material. Vitreous is a solid substance that is not crystallized, is in an unstable state, and has a high chemical activity. The main reason that the water-quenched slag contains a large amount of vitreous is that molten titanium slag of a high-temperature liquid high-titanium electric furnace is rapidly cooled by high-pressure water quenching liquid, so that atoms or ions in the titanium slag are not as good as to form regularly arranged crystal substances, and the molten titanium slag is solidified to form the vitreous.

As can be seen from tables 8 and 9 above, the Al-Si-Ca minerals are present in both of the titanium slags, but the ratio of the Al-Si-Ca minerals is very different, and the conventional titanium slag obtained in comparative example 1 has about 1:5:1.7 of Al-Si-Ca minerals, while the water-quenched slag obtained in example 1 has about 1:1.6:0.5 of Al-Si-Ca minerals. This shows that the water quenching process makes the traditional glass phase of the titanium slag transformed, and a part of the titanium slag is formed into glass with good acid solubility, which is beneficial to the subsequent leaching.

As can be seen from FIGS. 4 and 7, the two titanium slags also have obvious differences in particle shapes, and the conventional titanium slag prepared in comparative example 1 is produced by mechanical crushing and has obvious sections; the water quenching slag prepared in the embodiment 1 has a very smooth surface, most of which have a streamline surface, and the smooth and streamline surface can make the water quenching slag have stronger hydrophilicity in the acid leaching process, thereby enhancing the acid leaching capability.

In addition, the degree of dissociation of the aluminum-silicon-calcium mineral monomer in the water-quenched slag obtained in example 1 was high, whereas the aluminum-silicon-calcium mineral coexisted with the titanium mineral in the conventional titanium slag obtained in comparative example 1.

The phase difference between the water-quenched slag obtained in example 1 and the conventional titanium slag obtained in comparative example 1 is shown in Table 10 below.

TABLE 10 phase difference between conventional titanium slag and water-quenched slag

While particular embodiments of the present invention have been illustrated and described, it will be appreciated that the above embodiments are merely illustrative of the technical solution of the present invention and are not restrictive; those of ordinary skill in the art will understand that: modifications may be made to the above-described embodiments, or equivalents may be substituted for some or all of the features thereof without departing from the spirit and scope of the present invention; the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention; it is therefore intended to cover in the appended claims all such alternatives and modifications that are within the scope of the invention.