阅读说明：本技术 一种氯化法钛白废酸分段萃取回收有价元素的方法 (Method for recovering valuable elements by sectional extraction of titanium white waste acid by chlorination process ) 是由 陈卫平 聂东红 彭业云 李润民 薛攀 程长鑫 司利沙 于 2020-12-14 设计创作，主要内容包括：本发明公开了一种氯化法钛白废酸分段萃取回收有价元素的方法,包括以下步骤：S1、在氯化法钛白废酸中加入第一有机相,得到第一萃取余液和铁负载；铁负载反萃取后得到氯化铁溶液；S2、第一萃取余液中加入第二有机相,得到第二萃取余液和钪钛锆铌负载；S3、钪负载反萃取后得到钪钛锆铌富集物；S4、第二萃取余液进行调节ph值制液；S5、制液后加入第三有机相,得到钒铝负载和第三萃取余液；S6、钒铝负载反萃取后得到钒铝混合溶液；S7、第三萃取余液进行调节ph值制液；S8、制液后在锰萃取料液中加入第四有机相,得到锰负载和第四萃取余液；锰负载反萃取后得到含锰溶液；S9、将第四萃取余液中和、过滤后进行浓缩结晶,得到NaCl食盐和水,并循环利用。(The invention discloses a method for recovering valuable elements by sectional extraction of titanium white waste acid by a chlorination process, which comprises the following steps: s1, adding a first organic phase into the titanium dioxide waste acid obtained by the chlorination process to obtain a first raffinate and an iron load; carrying out iron load back extraction to obtain an iron chloride solution; s2, adding a second organic phase into the first extraction raffinate to obtain a second extraction raffinate and a scandium-titanium-zirconium-niobium load; s3, carrying out scandium load back extraction to obtain a scandium-titanium-zirconium-niobium concentrate; s4, adjusting the ph value of the second extraction raffinate to prepare liquid; s5, preparing a liquid, and then adding a third organic phase to obtain a vanadium-aluminum load and a third extraction raffinate; s6, carrying out back extraction on the vanadium and aluminum load to obtain a vanadium and aluminum mixed solution; s7, adjusting the ph value of the third extraction raffinate to prepare liquid; s8, adding a fourth organic phase into the manganese extraction feed liquid after liquid preparation to obtain manganese load and a fourth extraction residual liquid; carrying out back extraction on the manganese load to obtain a manganese-containing solution; and S9, neutralizing the fourth extraction raffinate, filtering, concentrating and crystallizing to obtain NaCl salt and water, and recycling.)

1. A method for recovering valuable elements by sectional extraction of titanium white waste acid by a chlorination process is characterized by comprising the following steps: the method comprises the following steps:

s1, adding an oxidant into the titanium white waste acid obtained by the chlorination process, then adding a first organic phase to extract iron, and obtaining a first extraction residual liquid and an iron-loaded organic phase after phase separation; carrying out iron stripping operation on the iron-loaded organic phase by using the first stripping solution to obtain an iron chloride solution;

s2, adding a second organic phase into the first extraction raffinate to extract scandium, and performing phase splitting to obtain a second extraction raffinate and a scandium loaded organic phase;

s3, washing the scandium-loaded organic phase by using a washing solution, adding a second stripping solution into the scandium-loaded organic phase to perform back extraction after washing, and filtering to obtain a scandium-titanium-zirconium-niobium concentrate;

s4, carrying out alkali neutralization operation on the second extraction raffinate, and adjusting acidity (PH value) to obtain vanadium-aluminum extraction feed liquid;

s5, adding a third organic phase into the vanadium-aluminum extraction feed liquid, extracting vanadium and aluminum, and separating phases to obtain a vanadium-aluminum loaded organic phase and a third extraction raffinate;

s6, adding a third strip liquor into the vanadium-aluminum loaded organic phase, and carrying out back-extraction on vanadium-aluminum to obtain a vanadium-aluminum mixed solution; after the vanadium-aluminum mixed solution is subjected to oxidation and hydrolysis vanadium precipitation, an aluminum-containing solution and a poly-vanadate precipitate are obtained;

s7, carrying out alkali neutralization operation on the third extraction raffinate, and adjusting the acidity (PH value) to obtain manganese extraction feed liquid;

s8, adding a fourth organic phase into the manganese extraction feed liquid, extracting manganese, and performing phase splitting to obtain a manganese loaded organic phase and a fourth extraction raffinate; adding a fourth strip liquor into the manganese load, and carrying out strip manganese operation to obtain a manganese sulfate solution;

s9, neutralizing the fourth extraction raffinate with alkali, adjusting acidity (PH value), and filtering to obtain a sodium chloride solution; the sodium chloride solution is concentrated and crystallized to obtain salt and water, and the water and the salt are recycled.

2. The method for recovering valuable elements by sectional extraction of titanium dioxide waste acid through a chlorination process as claimed in claim 1, which is characterized in that: the oxidant in the step S1 is one of hydrogen peroxide, sodium chlorate, sodium hypochlorite and sodium chlorite;

when the operation of extracting iron is carried out, the O/A = 1-5: 1 of the extraction ratio of the first organic phase to the titanium white waste acid obtained by the chlorination process after oxidation;

when the back extraction of iron is carried out, the O/A ratio of the first back extraction solution to the back extraction of iron load is = 1-10: 1; the first strip liquor is water with the temperature of 20-60 ℃.

3. The method for recovering valuable elements by sectional extraction of titanium dioxide waste acid by a chlorination process as claimed in claim 2, which is characterized in that: when scandium extraction is performed in step S2, the ratio O/a of the second organic phase to the first raffinate =1:10 to 50.

4. The method for recovering valuable elements by sectional extraction of titanium dioxide waste acid through a chlorination process as claimed in claim 3, wherein the method comprises the following steps: when the washing operation is performed in step S3, the ratio of O/a =1 to 10 in the washing liquid to that in the scandium-loaded washing: 1;

the cleaning solution is prepared by mixing 3-6 mol/l sulfuric acid and 40% hydrofluoric acid, and the volume ratio of the sulfuric acid to the hydrofluoric acid is 1: 0.005-0.2;

when the back extraction operation is performed, the O/a ratio of the second stripping solution to the stripping of the washed scandium-loaded organic phase is =1: 1-3; the second stripping solution is 2.5-7 mol/l of liquid caustic soda.

5. The method for recovering valuable elements by sectional extraction of titanium dioxide waste acid through a chlorination process as claimed in claim 4, wherein the method comprises the following steps: when the second raffinate is subjected to liquid preparation in the step S4, the alkali used is one of sodium carbonate, sodium hydroxide, calcium carbonate and carbide mud, and the PH value of the neutralization is 2-3.

6. The method for recovering valuable elements by sectional extraction of titanium dioxide waste acid through a chlorination process as claimed in claim 5, wherein the method comprises the following steps: when the vanadium-aluminum extraction operation is performed in step S5, the extraction ratio O/a of the third organic phase to the vanadium-aluminum extract liquid =1:1 to 8.

7. The method for recovering valuable elements by sectional extraction of titanium dioxide waste acid through a chlorination process as claimed in claim 6, wherein the method comprises the following steps: when the back extraction of vanadium and aluminum is performed in the step S6, the O/a ratio of the third back extraction solution to the back extraction of the vanadium-aluminum loaded organic phase is = 1-7: 1; the third strip liquor is 1-5 mol/l sulfuric acid.

8. The method for recovering valuable elements by sectional extraction of titanium dioxide waste acid through a chlorination process as claimed in claim 7, wherein the method comprises the following steps: and in the step S7, when the third raffinate is subjected to alkali neutralization, the alkali used is one of sodium carbonate, sodium hydroxide, calcium carbonate and carbide mud, and the neutralized ph value is 4-6.

9. The method for recovering valuable elements by sectional extraction of titanium dioxide waste acid through a chlorination process as claimed in claim 8, wherein the method comprises the following steps: when the manganese extraction operation is performed in the step S8, the extraction ratio O/A of the fourth organic phase to the manganese extraction feed liquid is =1: 2-6; when the back extraction of manganese is carried out, the O/A ratio of the fourth back extraction solution to the back extraction of the manganese loaded organic phase is = 1-6: 1; the fourth stripping solution is 1.5-3 mol/l sulfuric acid.

10. The method for recovering valuable elements by sectional extraction of titanium dioxide waste acid through a chlorination process as claimed in claim 9, wherein the method comprises the following steps: the first organic phase is prepared by mixing one of N235 and N503, sec-octanol, TBP and solvent oil; the second organic phase, the third organic phase and the fourth organic phase are all prepared by mixing one of P204, P507 and P272, one of TBP and secondary octanol and solvent oil.

Technical Field

The invention relates to the field of metallurgy, in particular to a method for recovering valuable elements by sectional extraction of titanium white waste acid by a chlorination process.

Background

Titanium dioxide is an important chemical raw material and is widely applied to various important industrial fields influencing national economy. In the boiling chlorination process for producing titanium dioxide, 0.4-0.6 m is generated for each ton of titanium dioxide³A waste hydrochloric acid solution. The waste hydrochloric acid solution is generally neutralized by lime milk to generate a large amount of slag phase and then is discarded, so that not only is a large amount of resources wasted, but also the environment is seriously polluted; because the waste acid contains a large amount of iron, manganese and aluminum and a small amount of elements such as titanium, zirconium, niobium, scandium, vanadium and the like; the valuable elements have high value, and a method for comprehensively recovering the valuable elements in the waste acid and reducing the valuable elements is necessary to be researchedLess waste water and waste residue discharge, and environmental protection.

Disclosure of Invention

The invention aims to solve the problems and provides a method which is convenient to operate, adopts sectional extraction on titanium white waste acid obtained by a chlorination process, recovers valuable elements, and solves the problems of discharge and cyclic utilization of waste water and waste residues.

In order to achieve the purpose, the technical scheme of the invention is as follows: (before the following modification references)

A method for recovering valuable elements by sectional extraction of titanium white waste acid by a chlorination process comprises the following steps:

s1, adding an oxidant into the titanium white waste acid obtained by the chlorination process, then adding a first organic phase to extract iron, and obtaining a first extraction residual liquid and an iron load after phase separation; carrying out back extraction of iron on the iron load by using the first back extraction solution to obtain an iron chloride solution;

s2, adding a second organic phase into the first extraction raffinate to perform scandium extraction operation, and obtaining a second extraction raffinate and a scandium load after phase separation;

s3, washing the scandium load by using a washing liquid, adding a second stripping liquid into the scandium load after washing to perform back extraction operation, and filtering to obtain a scandium-titanium-zirconium-niobium concentrate;

s4, adjusting the pH value of the second extraction raffinate to prepare a solution, and obtaining a vanadium-aluminum extraction feed solution;

s5, adding a third organic phase into the vanadium-aluminum extraction feed liquid to extract vanadium and aluminum, and performing phase splitting to obtain vanadium-aluminum load and a third extraction raffinate;

s6, adding a third strip liquor into the vanadium-aluminum load to carry out vanadium-aluminum stripping operation to obtain a vanadium-aluminum mixed solution; oxidizing and hydrolyzing the vanadium-aluminum mixed solution to precipitate vanadium to obtain an aluminum-containing solution and a poly-vanadate precipitate;

s7, adjusting the pH value of the third extraction residual liquid to prepare liquid, and obtaining manganese extraction liquid;

s8, adding a fourth organic phase into the manganese extraction feed liquid to perform manganese extraction operation, and obtaining manganese load and a fourth extraction residual liquid after phase splitting; adding a fourth strip liquor into the manganese load to carry out strip manganese operation to obtain a manganese sulfate solution;

s9, neutralizing and filtering the fourth extraction raffinate to obtain a sodium chloride solution; and concentrating and crystallizing the sodium chloride solution to obtain NaCl solid and water, and recycling the water.

Further, the oxidant in step S1 is one of hydrogen peroxide, sodium chlorate, sodium hypochlorite and sodium chlorite;

when the operation of extracting iron is carried out, the O/A = 1-5: 1 of the extraction ratio of the first organic phase to the titanium white waste acid obtained by the chlorination process after oxidation;

when the back extraction of iron is carried out, the O/A ratio of the first back extraction solution to the back extraction of iron load is = 1-10: 1; the first stripping solution is water with the temperature of 20-60 ℃, hydrochloric acid with the concentration of 0.1-0.5 mol/l or sodium chloride solution with the concentration of 1-20%.

Further, when scandium extraction is performed in step S2, the ratio O/a of the second organic phase to the first raffinate =1:10 to 50.

Further, when the washing operation is performed in step S3, the ratio of O/a =1 to 10: 1;

the cleaning solution is prepared by mixing 3-6 mol/l sulfuric acid and 40% hydrofluoric acid, and the volume ratio of the sulfuric acid to the hydrofluoric acid is 1: 0.005-0.2;

when the stripping operation was performed, the second stripping solution was compared to the stripping of the scandium loading after washing with O/a =1: 1-3; the second stripping solution is 2.5-7 mol/l of liquid caustic soda.

Further, when the second raffinate is subjected to the liquid preparation operation in step S4, the used alkali is one of sodium carbonate, sodium hydroxide, calcium carbonate and calcium carbide mud, and the ph value during liquid preparation is 2-3.

Further, when the vanadium-aluminum extraction operation is performed in step S5, the extraction ratio O/a of the third organic phase to the vanadium-aluminum extract liquid is =1:1 to 8.

Further, when the vanadium-aluminum stripping operation is performed in step S6, the O/a ratio of the third stripping solution to the vanadium-aluminum loaded stripping solution is = 1-7: 1; the third strip liquor is 1-5 mol/l sulfuric acid.

Further, when the third raffinate is subjected to the liquid preparation operation in step S7, the used alkali is one of sodium carbonate, sodium hydroxide, calcium carbonate and calcium carbide mud, and the ph value during liquid preparation is 4-6.

Further, when the manganese extraction operation is performed in the step S8, the extraction ratio O/a of the fourth organic phase to the manganese extraction feed liquid is =1: 2-6; when back extraction of manganese is carried out, the O/A ratio of the fourth back extraction solution to the back extraction of manganese load is = 1-6: 1; the fourth stripping solution is 1.5-3 mol/l sulfuric acid.

Further, the first organic phase is prepared by mixing one of N235 and N503, sec-octanol and solvent oil; the second organic phase, the third organic phase and the fourth organic phase are all prepared by mixing one of P204, P507 and P272, one of TBP and secondary octanol and solvent oil.

Compared with the prior art, the invention has the advantages and positive effects that:

according to the invention, the iron loaded organic phase is obtained by using the first organic phase for extraction, the scandium loaded organic phase is obtained by using the second organic phase for extraction, the vanadium-aluminum loaded organic phase is obtained by using the third organic phase for extraction, the manganese loaded organic phase is obtained by using the fourth organic phase for extraction, and then the back extraction operation is carried out on various loaded organic phases by using various back extraction solutions to obtain the concentrates of various valuable elements, so that the recovery of the valuable elements in the titanium white waste acid by the chloride process is realized, the condition that the titanium white waste acid by the chloride process is directly discarded or neutralized to cause serious environmental pollution is avoided, meanwhile, the waste of various metal resources in the titanium white waste acid by the chloride process is effectively avoided by the operation, and the value of the waste acid is improved.

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 only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a block diagram of the framework of the present 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 from the embodiments of the present invention by a person skilled in the art without any creative effort, should be included in the protection scope of the present invention.

Embodiment 1, as shown in fig. 1, this embodiment discloses a method for recovering valuable elements by stepwise extraction of titanium white waste acid by a chlorination process, which includes the following steps:

s1, adding hydrogen peroxide into titanium white waste acid obtained by a chlorination process, carrying out iron oxide operation, carrying out oxidation end point potential of 710mv, then carrying out iron extraction operation by using 50% of N235, 10% of secondary octanol and 40% of solvent oil, wherein the extraction ratio is O/A =3:1, and phase splitting is carried out to obtain a first extraction raffinate and an iron load; and (3) performing back extraction operation on the iron-loaded organic phase by using 50-degree water, wherein the back extraction phase ratio is O/A =6:1, and obtaining an iron chloride solution.

S2, adding 20% of P204+5% of TBP +75% of solvent oil into the first extraction raffinate to extract scandium, titanium, zirconium and niobium, wherein the extraction ratio is O/A =1:10, and phase separation is carried out to obtain a second extraction raffinate and a scandium, titanium, zirconium and niobium loaded organic phase;

s3, washing the scandium-titanium-zirconium-niobium load by using a washing solution, wherein the washing solution is 6mol/l sulfuric acid and 40% hydrofluoric acid, and the volume ratio of the sulfuric acid to the hydrofluoric acid is 1: 0.05; wash phase ratio O/a =2: 1; adding 2mol/l of sodium hydroxide solution into the scandium-titanium-zirconium-niobium loaded organic phase to perform back extraction operation, wherein the back extraction phase ratio is O/A =1: 2; the back extraction temperature is 60 ℃, and the scandium, titanium, zirconium and niobium concentrate is obtained after filtration;

s4, adding sodium hydroxide into the second extraction raffinate, and adjusting the pH to 2.7 to obtain a vanadium-aluminum extraction feed liquid;

s5, adding 20% of P507, 10% of secondary octanol and 70% of solvent oil into the vanadium-aluminum extraction feed liquid, extracting vanadium and aluminum, wherein the extraction ratio is O/A =1:2, and performing phase separation to obtain a vanadium-aluminum loaded organic phase and a third extraction raffinate;

s6, adding 2mol/l sulfuric acid into the vanadium-aluminum loaded organic phase to perform back extraction of vanadium and aluminum, wherein the back extraction ratio is O/A =3:1, so as to obtain a vanadium-aluminum mixed solution; carrying out sodium chlorate vanadium oxidation and hydrolysis vanadium precipitation on the vanadium-aluminum mixed solution to obtain an aluminum-containing solution and a poly-vanadate precipitate;

s7, adding sodium carbonate into the third extraction raffinate, and adjusting the pH value to 5.2 to obtain manganese extraction feed liquid;

s8, adding 15% of P204+5% of TBP +80% of solvent oil into the manganese extraction feed liquid to perform manganese extraction, wherein the extraction ratio is O/A =1:2, and performing phase separation to obtain a manganese loaded organic phase and a fourth extraction raffinate; adding 3mol/l sulfuric acid into the manganese-loaded organic phase to perform manganese stripping operation, wherein the stripping ratio is O/A =2:1 to obtain a manganese sulfate solution;

s9, neutralizing the fourth raffinate with sodium hydroxide until the pH value is 9, and concentrating and crystallizing the filtrate to obtain NaCl salt and water; the salt and water are recycled.

Embodiment 2, as shown in fig. 1, this embodiment discloses a method for recovering valuable elements by stepwise extraction of titanium white waste acid by a chlorination process, which includes the following steps:

s1, adding sodium hypochlorite into titanium white waste acid obtained by a chlorination process, carrying out iron oxide operation, carrying out oxidation end point potential of 800mv, then carrying out iron extraction operation by using 40% of N235, 12% of secondary octanol and 48% of solvent oil, wherein the extraction ratio is O/A =2:1, and carrying out phase separation to obtain a first extraction raffinate and an iron-loaded organic phase; carrying out back extraction operation on the iron load by using 60-degree water, wherein the back extraction ratio is O/A =4:1, and obtaining an iron chloride solution;

s2, adding 20% of P272+5% of TBP +75% of solvent oil into the first extraction raffinate to extract scandium, titanium, zirconium and niobium, wherein the extraction ratio is O/A =1:40, and phase separation is carried out to obtain a second extraction raffinate and a scandium, titanium, zirconium and niobium loaded organic phase;

s3, washing the scandium-titanium-zirconium-niobium load by using a washing solution, wherein the washing solution is 3.5mol/l sulfuric acid and 40% hydrofluoric acid, and the volume ratio of the sulfuric acid to the hydrofluoric acid is 1: 0.1; wash phase ratio O/a =1: 1; adding 5mol/l of sodium hydroxide solution into the scandium-titanium-zirconium-niobium loaded organic phase to perform back extraction operation, wherein the back extraction phase ratio is O/A =1: 1; the back extraction temperature is 70 ℃, and the scandium, titanium, zirconium and niobium concentrate is obtained after filtration;

s4, adding sodium carbonate into the second extraction raffinate to adjust the PH value to 3, and obtaining vanadium-aluminum extraction feed liquid;

s5, adding 30% of p204+10% of TBP +60% of solvent oil into the vanadium-aluminum extraction feed liquid, extracting vanadium and aluminum, wherein the extraction ratio is O/A =1:1, and performing phase separation to obtain a vanadium-aluminum loaded organic phase and a third extraction raffinate;

s6, adding 1.5mol/l sulfuric acid into the vanadium-aluminum loaded organic phase to perform back extraction of vanadium and aluminum, wherein the back extraction ratio is O/A =6:1 to obtain a vanadium-aluminum mixed solution; carrying out sodium chlorite vanadium oxide and hydrolysis vanadium precipitation on the vanadium-aluminum mixed solution to obtain an aluminum-containing solution and a poly-vanadate precipitate;

s7, adding liquid alkali into the third extraction raffinate to adjust the pH value to 5.6, and obtaining manganese extraction feed liquid;

s8, adding 20% of P507, 10% of TBP and 70% of solvent oil into the manganese extraction feed liquid to perform manganese extraction, wherein the extraction ratio is O/A =1:3, and performing phase separation to obtain a manganese loaded organic phase and a fourth extraction raffinate; adding 2mol/l sulfuric acid into the manganese-loaded organic phase to perform manganese stripping operation, wherein the stripping ratio is O/A =6:1, so as to obtain a manganese sulfate solution;

s9, neutralizing the fourth raffinate with liquid alkali to pH 8, and concentrating and crystallizing the filtrate to obtain NaCl salt and water;

according to the invention, the iron-loaded organic phase is obtained by using the first organic phase for extraction, the scandium-titanium-zirconium-niobium-loaded organic phase is obtained by using the second organic phase for extraction, the vanadium-aluminum-loaded organic phase is obtained by using the third organic phase for extraction, the manganese-loaded organic phase is obtained by using the fourth organic phase for extraction, and then the back extraction operation is carried out on various loaded organic phases by using various back extraction solutions to obtain the concentrates of various valuable elements, so that the recovery of the valuable elements in the titanium white waste acid by the chloride process is realized, the condition that the waste acid by the chloride process is directly discarded to cause serious environmental pollution is avoided, meanwhile, the waste of various metal resources in the titanium white waste acid by the chloride process is effectively avoided by the operation, and the value of the waste acid is improved.