阅读说明：本技术 一种钛回收硫酸直接浸出工艺 (Direct leaching process for titanium recovery sulfuric acid ) 是由 张裕书 高利坤 穆宇 张少翔 张新良 蒋朋 陈超 刘能云 于 2020-07-09 设计创作，主要内容包括：本发明公开了一种钛回收硫酸直接浸出工艺,包括：(1)将原矿研磨至细粒；(2)将研磨后的原矿和硫酸溶液加入到浸出器中加热至沸腾进行第一段浸出得到第一段矿浆；(3)将所述第一段矿浆进行过滤得到一段浸出渣和一段浸出液；(4)将所述一段浸出渣和硫酸溶液加入到浸出器中加热至沸腾进行第二段浸出得到第二段矿浆；(5)将所述第二段矿浆进行过滤得到二段浸出渣和二段浸出液。本发明经历一段和二段浸出后,可获得了铁总浸出率99.69％,钛总浸出率91.55％,铝总浸出率98.84％。(The invention discloses a direct leaching process for recovering sulfuric acid from titanium, which comprises the following steps: (1) grinding raw ore to fine particles; (2) adding the ground raw ore and a sulfuric acid solution into a leacher, heating to boil, and performing first-stage leaching to obtain first-stage ore pulp; (3) filtering the first-stage ore pulp to obtain first-stage leaching slag and first-stage leaching liquid; (4) adding the first-stage leaching residue and a sulfuric acid solution into a leacher, heating to boil, and performing second-stage leaching to obtain second-stage ore pulp; (5) and filtering the second-stage ore pulp to obtain second-stage leaching slag and second-stage leaching liquid. After the first-stage leaching and the second-stage leaching, the total leaching rate of iron is 99.69%, the total leaching rate of titanium is 91.55%, and the total leaching rate of aluminum is 98.84%.)

1. A direct leaching process of sulfuric acid recovered from titanium is characterized by comprising the following steps:

s1: grinding raw ore to fine particles;

s2: adding the ground raw ore and a sulfuric acid solution into a leacher, heating to boil, and performing first-stage leaching to obtain first-stage ore pulp;

s3: filtering the first-stage ore pulp to obtain first-stage leaching slag and first-stage leaching liquid;

s4: adding the first-stage leaching residue and a sulfuric acid solution into a leacher, heating to boil, and performing second-stage leaching to obtain second-stage ore pulp;

s5: and filtering the second-stage ore pulp to obtain second-stage leaching slag and second-stage leaching liquid.

2. The direct leaching process of sulfuric acid for titanium recovery according to claim 1, characterized in that: the raw ore ground to-0.075 mm in the step S1 accounts for 65-95%.

3. The direct leaching process of sulfuric acid for titanium recovery according to claim 1, characterized in that: the concentration of the sulfuric acid solution in the step S2 is 40-80%; the leaching time in the step S2 is 60-150 min; the solid ratio of the leaching solution in the step S2 is 4-6.

4. The direct leaching process of sulfuric acid for titanium recovery according to claim 3, characterized in that: the leaching temperature in the step S2 is 140 °.

5. The direct leaching process of sulfuric acid for titanium recovery according to claim 1, characterized in that: the step S3 specifically includes: and cooling the first-stage ore pulp to 90 ℃, and filtering to obtain first-stage leaching residue.

6. The direct leaching process of sulfuric acid for titanium recovery according to claim 1, characterized in that: the concentration of the sulfuric acid solution in the step S4 is 85-95%; the leaching time in the step S4 is 90-150 min; the solid ratio of the leaching solution in the step S4 is 3-4.

7. The direct leaching process of sulfuric acid for titanium recovery according to claim 6, characterized in that: the leaching temperature in the step S4 is 250 °.

8. The direct leaching process of sulfuric acid for titanium recovery according to claim 1, characterized in that: the step S5 specifically includes: and cooling the second-stage ore pulp to 90 ℃, and filtering to obtain second-stage leaching residues.

9. The direct leaching process of sulfuric acid for titanium recovery according to claim 1, characterized in that: the process also comprises adding the second-stage leachate to the leacher in the step S2, heating to boiling and carrying out the first-stage leaching.

10. The direct leaching process of sulfuric acid for titanium recovery according to claim 1, characterized in that: the grinding equipment adopted in the step S1 is an XMB-70 three-roller four-cylinder rod grinder; the leachers in the steps S2 and S4 are mechanical agitation leachers; the steps S2 and S4 are heated to boiling by an electric furnace; filtering in the steps S3 and S5 by adopting a DZ-5C vacuum filter; and drying the first-stage leaching residue and the second-stage leaching residue obtained in the steps S3 and S5 respectively by adopting an HG101-3 electrothermal blowing drying box.

Technical Field

The invention belongs to the technical field of titanium recovery in raw ores, and particularly relates to a direct leaching process for recovering sulfuric acid from titanium.

Background

TiO is the main valuable component in the sedimentary ore₂Mainly exists in anatase, and the particle size of anatase is-30 μm. The gangue minerals are mainly hematite, quartz, kaolinite and rectorite. Kaolinite and rectorite are aluminum carrier minerals, the particles of which are fine, are in a fine dispersion state and are distributed in a cryptocrystalline aggregate, and the surfaces of the kaolinite and the rectorite are turbid; the hematite and limonite are in a fine dispersion state, the granularity of the hematite and limonite is about 2 mu m, and the hematite and the limonite are locally distributed as a lump aggregate; the quartz is fine microcrystal and exists in a fine granular monomer or irregular aggregate shape, the particle size of the monomer is about 2-8 mu m, the distribution is not uniform, and the quartz is mostly filled in the pore space of the ore. The primary mineral particle size is so fine and dispersed that effective separation and recovery of anatase is difficult with conventional physical beneficiation processes. Therefore, the invention provides a chemical beneficiation (chemical leaching) process for recycling titanium.

Disclosure of Invention

The invention provides a direct leaching process for recovering sulfuric acid from titanium, which aims to overcome the defects in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme:

a direct leaching process of titanium recovery sulfuric acid comprises the following steps:

s1: grinding raw ore to fine particles;

s2: adding the ground raw ore and a sulfuric acid solution into a leacher, heating to boil, and performing first-stage leaching to obtain first-stage ore pulp;

s3: filtering the first-stage ore pulp to obtain first-stage leaching slag and first-stage leaching liquid;

s4: adding the first-stage leaching residue and a sulfuric acid solution into a leacher, heating to boil, and performing second-stage leaching to obtain second-stage ore pulp;

s5: and filtering the second-stage ore pulp to obtain second-stage leaching slag and second-stage leaching liquid.

As a further description of the above technical solution: the raw ore ground to-0.075 mm in the step S1 accounts for 65-95%.

As a further description of the above technical solution: the concentration of the sulfuric acid solution in the step S2 is 40-80% (volume concentration).

As a further description of the above technical solution: the leaching time in the step S2 is 60-150 min.

As a further description of the above technical solution: the solid ratio of the leaching solution in the step S2 is 4-6.

As a further description of the above technical solution: the leaching temperature in the step S2 is 140 °.

As a further description of the above technical solution: the step S3 specifically includes: and cooling the first-stage ore pulp to 90 ℃, and filtering to obtain first-stage leaching residue.

As a further description of the above technical solution: the concentration of the sulfuric acid solution in the step S4 is 85 to 95% (volume concentration).

As a further description of the above technical solution: the leaching time in the step S4 is 90-150 min.

As a further description of the above technical solution: the solid ratio of the leaching solution in the step S4 is 3-4.

As a further description of the above technical solution: the leaching temperature in the step S4 is 250 °.

As a further description of the above technical solution: the step S5 specifically includes: and cooling the second-stage ore pulp to 90 ℃, and filtering to obtain second-stage leaching residues.

As a further description of the above technical solution: the process also comprises adding the second-stage leachate to the leacher in the step S2, heating to boiling and carrying out the first-stage leaching.

As a further description of the above technical solution: the grinding equipment adopted in the step S1 is an XMB-70 three-roller four-cylinder rod mill.

As a further description of the above technical solution: the leachers in the steps S2 and S4 are mechanical agitation leachers.

As a further description of the above technical solution: the steps S2 and S4 are heated to boiling using an electric furnace.

As a further description of the above technical solution: and the steps S3 and S5 adopt a DZ-5C vacuum filter for filtration.

As a further description of the above technical solution: and drying the first-stage leaching residue and the second-stage leaching residue obtained in the steps S3 and S5 respectively by adopting an HG101-3 electrothermal blowing drying box.

The invention has the following beneficial effects:

1. after the first-stage leaching and the second-stage leaching, the total leaching rate of iron is 99.69%, the total leaching rate of titanium is 91.55%, and the total leaching rate of aluminum is 98.84%.

2. The test that the second-stage leachate returns to the first-stage leaching shows that the leaching effect is equivalent to that of the new acid with the same concentration, the second-stage acid can return to the first-stage leaching for recycling, the process flow of the Yaan anatase two-stage countercurrent leaching is determined through the research of the first-stage leaching and the second-stage leaching, and the technical indexes that the total leaching rate of iron is 99.70%, the total leaching rate of titanium is 91.42% and the total leaching rate of aluminum is 98.79% are obtained.

3. The leaching solution containing H2SO4398.27g/L, Al2O339.89g/L and TiO27.15g/L, TFe 27.73.73 g/L can be obtained by two-stage countercurrent leaching, and can be used for recycling iron, aluminum and titanium.

4. The two-stage countercurrent leaching process can obtain final leached slag containing SiO287.50%, Al2O30.84%, TFe 0.18%, TiO21.73%, CaO 0.02%, MgO 0.012% and loss on ignition 10%, and the slag powder may be used as reinforcing agent for concrete, water glass and other material.

Drawings

FIG. 1 is a flow chart of a direct leaching process for recovering sulfuric acid from titanium provided by the invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. 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 raw ore mainly comprises hematite, kaolinite, rectorite, quartz and anatase, and the mineral contents of the raw ore are 30.63%, 18.63%, 15.12%, 14.74% and 5.46% respectively. The exploration test result shows that iron and aluminum in the ore are easier to leach than titanium, and if the leaching rate of titanium is high at one time, the sulfuric acid concentration and the leaching time of sulfuric acid leaching need to be increased, which inevitably increases the leaching cost. For this purpose, the test considers the study of the process conditions by means of a two-stage leaching process. The aim is to consider the leaching of iron and aluminium first in the first stage and to concentrate the leaching of titanium in the second stage.

As shown in fig. 1, a direct leaching process of sulfuric acid recovered from titanium comprises:

(1) the raw ore is ground to fine particles.

(2) Adding the ground raw ore and a sulfuric acid solution into a leacher, heating to boil, and carrying out first-stage leaching to obtain first-stage ore pulp.

(3) And filtering the first-stage ore pulp to obtain first-stage leaching slag and first-stage leaching liquid.

(4) And adding the first-stage leaching residue and the sulfuric acid solution into a leacher, heating to boil, and performing second-stage leaching to obtain second-stage ore pulp.

(5) And filtering the second-stage ore pulp to obtain second-stage leaching slag and second-stage leaching liquid.

(6) And (3) adding the second-stage leachate into the leacher in the step (2), heating to boil, and performing first-stage leaching to realize recycling.

In the embodiment, raw ore ground to-0.075 mm in the step (1) accounts for 65-95%; the concentration of the sulfuric acid solution in the step (2) is 40-80% (volume concentration); the leaching time in the step (2) is 60-150 min; the solid-to-liquid ratio of the leaching solution in the step (2) is 4-6; the leaching temperature in the step (2) is 140 degrees.

In this embodiment, the concentration of the sulfuric acid solution in the step (4) is 85-95% (volume concentration); the leaching time in the step (4) is 90-150 min; the solid-to-liquid ratio of the leaching solution in the step (4) is 3-4; the leaching temperature in the step S4 is 250 °.

In this embodiment, the steps (1) and (2) are specifically: 1000g of raw ore is fed, raw ore with the grain size of-2 mm is ground to 85% of-0.075 mm, the sulfuric acid concentration is 50%, the liquid-solid ratio is 5:1, the leaching time is 120min, and the leaching temperature is 140 ℃. Obtaining first-stage leaching residue: TiO2₂14.13％、SiO₂76.36％、Al₂O₃3.75%, TFe 1.40%, slag leaching rate: TiO2₂8.42％、SiO₂3.96％、Al₂O₃92.97 percent and TFe97.03 percent, and the yield of the leached residue is 40.12 percent. Mixing the first-stage leaching solution with a washing solution: TiO2₂1.04g/L、SiO₂2.01g/L、Al₂O₃45.02g/L, TFe 33.43.43 g/L, and the total volume of the solution is 5.75L. The first stage leaching mainly comprises leaching iron and aluminum in ores, and the produced leaching slag has low aluminum and iron contents, so that favorable conditions are created for leaching titanium in the next step.

In this embodiment, the step (3) is specifically: and cooling the first-stage ore pulp to 90 ℃, and filtering to obtain first-stage leaching residue.

In this embodiment, the step (4) specifically includes: 1000g of feed, 95 percent of sulfuric acid concentration and 3 percent of leaching solution solid ratio are heated to boiling leaching (250 ℃), and the leaching time is 120 min. Obtaining second-stage leaching residue: TiO2₂1.71％、Al₂O₃0.81%, TFe0.19%, total leaching rate: TiO2₂91.55％、Al₂O₃98.84 percent, TFe 99.69 percent and the operation yield of the leached slag is 76.25 percent. Mixing the second-stage leaching solution with a washing solution: TiO2₂23.13g/L、Al₂O₃6.94g/L, TFe 2.24.24 g/L, and the total volume of the solution is 2.04L. In this embodiment, the step (5) specifically includes: and cooling the second-stage ore pulp to 90 ℃, and filtering to obtain second-stage leaching residues.

In this embodiment, the step (6) adds the second-stage leachate to the leacher in the step (2), and heats the second-stage leachate to boiling for the first-stage leaching.

After the raw ore is leached by two stages, most of the titanium-iron-aluminum components are dissolved out, and particularly, the leaching rate of the titanium which is difficult to dissolve in acid is over 90 percent under the condition of two stages of high acid. However, the acidity of the leachate obtained by the second-stage leaching is high, and the leachate contains iron, titanium and aluminum, so that the leachate is convenient to comprehensively utilize, the leachate obtained by the second-stage leaching is returned to the first-stage leaching for leaching, whether the consumption of the neo-acid obtained by the first-stage leaching can be reduced is examined, and the similar leaching index is achieved.

The test was run at 1000g feed and the other test conditions were as before. The yield of the first-stage leaching residue of the recycled acid is 40.25 percent, and the contents of the leaching residues are respectively as follows: TiO2₂14.21％、Al₂O₃3.72%, TFe 1.37%; the leaching rates of the slag meter are respectively as follows: TiO2₂7.60％、Al₂O₃93.00% and TFe 97.08%. The yield of the first-stage leaching residue of the new acid is 40.12 percent, and the contents of the leaching residues are respectively as follows: TiO2₂14.13％、Al₂O₃3.75%, TFe 1.40%; the leaching rates of the slag meter are respectively as follows: TiO2₂8.42％、Al₂O₃92.97%, TFe97.03%; the contents of the recycled acid first-stage leaching solution and the washing solution after mixing are respectively as follows: h₂SO₄398.72g/L、TiO₂7.15g/L、TFe 27.73g/L、Al₂O₃39.89g/L, and the total volume of the solution is 7.40L. After the first stage leaching operation adopts second-stage acid for recycling leaching, the leaching indexes of iron, aluminum and titanium are equivalent to the leaching result of the new acid, so that the second-stage leaching solution can be returned to the first stage for use.

In the embodiment, the grinding equipment adopted in the step (1) is an XMB-70 three-roller four-cylinder rod mill; the leacher in the steps (2) and (4) is a mechanical stirring leacher; heating the steps (2) and (4) to boiling by using an electric furnace; filtering in the steps (3) and (5) by adopting a DZ-5C vacuum filter; and (4) drying the first-stage leached residues and the second-stage leached residues obtained in the steps (3) and (5) by adopting an HG101-3 electrothermal blowing drying box.

The Yaan Yanxi channel titanium ore recycling process is a two-section countercurrent sulfuric acid leaching process. The technological process is shown in figure 1, the technical parameters of the leaching process are as follows: raw ore with the feeding fineness of-0.075 mm accounts for more than 85% of the total raw ore, the sulfuric acid concentration is 50%, the liquid-solid ratio is 5:1, the leaching temperature is 140 ℃, and the leaching time is 120 min; the conditions of the second stage leaching are as follows: the concentration of sulfuric acid is 95%, the liquid-solid ratio is 3:1, the leaching temperature is 250 ℃, and the leaching time is 120 min. The contents of the first-stage leaching residues are respectively as follows: TiO2₂14.21％、Al₂O₃3.72%, TFe 1.37%; the corresponding leaching rates are respectively as follows: TiO2₂7.60％、Al₂O₃93.00%, TFe 97.08%; the contents of the second-stage leaching residues are respectively as follows: TiO2₂1.73％、Al₂O₃0.84%, TFe 0.18%; the corresponding leaching rates are respectively as follows: TiO2₂90.72％、Al₂O₃82.78%, TFe 89.98%; the total leaching rates are respectively: TiO2₂91.42％、Al₂O₃98.79% and TFe99.70%. The content of the mixed leaching solution and the washing solution is respectively as follows: h₂SO₄398.72g/L、TiO₂7.15g/L、TFe27.73g/L、Al₂O₃39.89g/L, and the total volume of the solution is 7.40L. The content of main elements in the leaching residue is shown in a table 1-1, and the measurement result of part of physical property parameters of the micro powder of the finally leached residue after grinding is shown in a table 1-2. The main mineral of the final leaching residue of Yaan Yanxi channel titanium ore is silicon dioxide, and the micro powder of the milled leaching residue is 7d, active silicon dioxide with the activity index of 95 percent, and the slag powder can be used as a concrete reinforcing agent and a raw material for producing water glass and the like.

TABLE 1-1 Yaan Yanxi channel titanium mine final leaching residue multielement analysis result

Principal Components	TiO2	Al2O3	TFe	SiO2
					Content (%)	1.73	0.84	0.18	87.50
Principal Components	CaO	MgO	K2O	Loss on ignition
					Content (%)	0.02	0.012	0.094	10

TABLE 1-2 measurement results of some physical property parameters of the final leached slag micropowder of Yaan Yanxi channel titanium mine

1. The invention determines the optimal process conditions of the first stage leaching as follows through a detailed first stage leaching condition test: grinding fineness of-0.075 mm accounts for 85.00%, sulfuric acid concentration is 50%, leaching solution solid ratio is 5, leaching time is 120min, and leaching temperature is 140 ℃. Under the optimal condition, the leaching rate of iron is 97.08 percent, the leaching rate of titanium is 7.60 percent, and the leaching rate of aluminum is 93.00 percent; the slag contains 1.37 percent of TFe and TiO₂14.13％、Al₂O₃3.72% of good index.

2. The invention determines the optimal conditions of the second stage leaching to be as follows through a detailed second stage leaching condition test: the concentration of sulfuric acid is 95%, the liquid-solid ratio is 3, the leaching time is 120min, and the leaching temperature is 250 ℃. Under the best condition, the total leaching rate of iron is 99.69 percent, the total leaching rate of titanium is 91.55 percent, the total leaching rate of aluminum is 98.84 percent, and the second-stage slag contains 0.19 percent of TFe and 0.19 percent of TiO₂1.71％、Al₂O₃Good index of 0.81%.

3. The test that the second-stage leaching solution returns to the first-stage leaching shows that the leaching effect is equivalent to that of the new acid with the same concentration, which indicates that the second-stage acid can return to the first-stage leaching for recycling, and through the research of the first-stage leaching and the second-stage leaching, the process flow of the Yaan anatase two-stage countercurrent leaching is determined, and the technical indexes of 99.70% of the total leaching rate of iron, 91.42% of the total leaching rate of titanium and 98.79% of the total leaching rate of aluminum are obtained.

4. H can be obtained by two-stage countercurrent leaching₂SO₄398.27g/L、Al₂O₃39.89g/L、TiO₂7.15g/L and TFe27.73g/L of leachate, which can be used for recycling iron, aluminum and titanium.

5. SiO-containing material can be obtained by two-stage countercurrent leaching₂87.50％、Al₂O₃0.84％、TFe 0.18％、TiO₂1.73 percent of CaO, 0.02 percent of MgO, 0.012 percent of MgO and 10 percent of loss on ignition of the final leaching slagThe ground micropowder has volume average particle size of 7.31 μm, surface area average particle size of 2.61 μm, and specific surface area of 951.9m²The slag powder can be used as a concrete reinforcing agent and a raw material for producing water glass and the like.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments or portions thereof without departing from the spirit and scope of the invention.