阅读说明：本技术 提高钛白废酸浓度的方法 (Method for improving concentration of titanium white waste acid ) 是由 马维平 杨仰军 石瑞成 孙科 于 2019-10-31 设计创作，主要内容包括：本发明属于废酸处理领域,具体公开了一种提高钛白废酸浓度的方法,旨在解决如何有效提高钛白废酸浓度并降低生产成本的问题。该提高钛白废酸浓度的方法,通过选取包括至少三个按级别由低到高依次分级设置的子反应器的气液反应器作为处理设备,来使钛白废酸与酸解尾气充分反应,从而达到提高钛白废酸浓度的目的。不仅能够有效提高生产效率,而且既可以通过使钛白废酸吸收酸解尾气中的酸雾和硫化物提升浓度,又可以通过吸收酸解尾气的热量产生更多的水蒸气,并被酸解尾气带走来进一步提升浓度,与现有的蒸馏浓缩处理方式相比,设备投入及能耗均更低。(The invention belongs to the field of waste acid treatment, and particularly discloses a method for improving the concentration of titanium white waste acid, aiming at solving the problems of effectively improving the concentration of the titanium white waste acid and reducing the production cost. According to the method for improving the concentration of the titanium white waste acid, the gas-liquid reactor comprising at least three sub-reactors which are arranged in a grading manner from low to high in sequence is selected as treatment equipment, so that the titanium white waste acid and the acidolysis tail gas are fully reacted, and the aim of improving the concentration of the titanium white waste acid is fulfilled. Not only can effectively improve production efficiency, both can promote concentration through acid mist and sulphide that make titanium dioxide spent acid absorb in the acidolysis tail gas in addition, can produce more vapor through the heat that absorbs the acidolysis tail gas again to taken away by the acidolysis tail gas and further promote concentration, compare with current distillation concentration processing mode, equipment input and energy consumption are all lower.)

1. The method for improving the concentration of the titanium white waste acid is characterized by comprising the following steps of:

step one, selecting a gas-liquid reactor comprising at least three sub-reactors (100) which are arranged in a grading manner from low to high in sequence as processing equipment, connecting a gas outlet of the sub-reactor (100) with a gas inlet of a sub-reactor (100) of the next stage, and connecting a liquid outlet of the sub-reactor (100) with a liquid inlet of the sub-reactor (100) of the previous stage;

secondly, introducing acidolysis tail gas into a gas inlet of the sub-reactor (100) at the highest level, and introducing titanium white waste acid into a liquid inlet of the sub-reactor (100) at the lowest level to react with the acidolysis tail gas;

conveying the titanium white waste acid reacted with the acidolysis tail gas into a previous-stage sub-reactor (100) to react with the acidolysis tail gas;

step four, when titanium white waste acid exists in the sub-reactor (100) at the highest level, the titanium white waste acid is conveyed to each sub-reactor (100) in a suspending way;

step five, the titanium white waste acid in each sub-reactor (100) is self-circulated and continuously reacts with the introduced acidolysis tail gas, and the concentration of the titanium white waste acid in the highest sub-reactor (100) is monitored in real time on line;

and step six, when the mass concentration of the titanium white waste acid in the highest-level sub-reactor (100) is detected to be 25% -30%, judging the titanium white waste acid to be a qualified product, suspending self-circulation, and conveying the qualified titanium white waste acid into a qualified product storage tank (300).

2. The method for increasing the concentration of titanium dioxide waste acid as claimed in claim 1, wherein: the sub-reactors (100) are leaching towers, venturi tubes or spraying pipelines.

3. The method for increasing the concentration of titanium dioxide waste acid as claimed in claim 1, wherein: the sub-reactor (100) comprises a reaction cylinder (110) and a waste acid storage tank (120); an acidolysis tail gas inlet (111) is formed in the bottom of the reaction cylinder (110), and an acidolysis tail gas outlet (112) is formed in the top of the reaction cylinder (110); a waste acid spraying device (113) with a nozzle facing the bottom of the reaction cylinder (110) is arranged in the reaction cylinder (110), and a liquid inlet of the waste acid spraying device (113) is connected with a liquid inlet of the reaction cylinder (110) through a pipeline (114); a liquid inlet of the reaction cylinder (110) is connected with a liquid outlet of a waste acid storage tank (120) through a circulating pump (130), and a liquid inlet of the waste acid storage tank (120) is connected with a liquid outlet of the reaction cylinder (110); the liquid outlet of the reaction cylinder (110) of the sub-reactor (100) at the highest level is connected with the liquid inlet of the qualified product storage tank (300) through a liquid outlet pump (310); the acidolysis tail gas inlet (111) is a gas inlet of the sub-reactor (100), and the acidolysis tail gas outlet (112) is a gas outlet of the sub-reactor (100); the liquid inlet of the reaction cylinder (110) is the liquid inlet of the sub-reactor (100), and the liquid outlet of the reaction cylinder (110) is the liquid outlet of the sub-reactor (100).

4. The method for increasing the concentration of titanium dioxide waste acid as claimed in claim 3, wherein: the number of the waste acid spraying devices (113) is at least two, and the waste acid spraying devices are distributed at intervals along the height direction of the reaction cylinder (110).

5. The method for increasing the concentration of titanium dioxide waste acid as claimed in claim 4, wherein: the reaction cylinder (110) is also internally provided with a gas distribution plate (115), and the gas distribution plate (115) is provided with at least two through holes which are uniformly distributed.

6. The method for increasing the concentration of titanium dioxide waste acid as claimed in claim 5, wherein: the number of the gas distribution plates (115) is equal to that of the waste acid spraying devices (113), and each gas distribution plate (115) is respectively positioned at the lower side of each waste acid spraying device (113).

7. The method for increasing the concentration of titanium dioxide waste acid as claimed in claim 1, 2, 3, 4, 5 or 6, wherein: in the second step, the temperature of the introduced acidolysis tail gas is 150-250 ℃.

8. The method for increasing the concentration of titanium dioxide waste acid as claimed in claim 7, wherein: the main component of the acidolysis tail gas is H₂O、H₂S、SO₂And SO₃。

9. The method for increasing the concentration of titanium dioxide waste acid as claimed in claim 7, wherein: the acidolysis tail gas is the tail gas generated in the acidolysis process of preparing titanium dioxide by a sulfuric acid method.

10. The method for increasing the concentration of titanium dioxide waste acid as claimed in claim 1, 2, 3, 4, 5 or 6, wherein: also includes the seventh step;

and step seven, repeating the step two to the step six, and circulating in the way to realize continuous production.

Technical Field

The invention belongs to the field of waste acid treatment, and particularly relates to a method for improving the concentration of titanium white waste acid.

Background

At present, most of titanium dioxide production adopts a sulfuric acid method, but the environmental pollution problem brought by the sulfuric acid method seriously restricts the development of the titanium dioxide industry. The biggest defect of preparing titanium dioxide by a sulfuric acid method is that the three wastes are more, and particularly the waste acid amount is large; in the production process, titanium white waste acid with different concentrations is produced in different processes, and waste acid with the concentration of 17-22% is obtained by filter pressing after hydrolysis, and is also called hydrolysis waste acid or concentrated waste acid. According to incomplete statistics, 6-8 t of titanium white waste acid with the concentration of about 20% is produced in each ton of titanium white powder on average; about 20 percent of the titanium dioxide waste acid can be directly returned to the acidolysis process for acidolysis or leaching, and most of the titanium dioxide waste acid is remained to be treated. There are two main utilization routes formed from the industrialization of the sulfuric acid method for preparing titanium white in 1918 to date: direct utilization and comprehensive utilization. However, both direct utilization and comprehensive utilization indicate that the application field is wider when the waste acid concentration is higher, and the recovery value of the titanium white waste acid with lower visible concentration is not high, so that the titanium white waste acid concentration needs to be improved. The existing main method for improving the concentration of titanium white waste acid is concentration treatment, namely, evaporation equipment is adopted to evaporate water in the waste acid to concentrate the titanium white waste acid. However, the concentration treatment method has the problems of huge equipment investment, expensive equipment use and maintenance cost, high energy consumption in the concentration process and the like, so that the production cost of the product is high and the product is difficult to accept by manufacturers.

Disclosure of Invention

The invention provides a method for improving the concentration of titanium white waste acid, and aims to solve the problems of effectively improving the concentration of the titanium white waste acid and reducing the production cost.

The technical scheme adopted by the invention for solving the technical problems is as follows: the method for improving the concentration of titanium white waste acid comprises the following steps:

step one, selecting a gas-liquid reactor comprising at least three sub-reactors which are arranged in a grading manner from low to high as treatment equipment, connecting an air outlet of a sub-reactor with an air inlet of a sub-reactor of the next stage, and connecting a liquid outlet of a sub-reactor with a liquid inlet of a sub-reactor of the previous stage;

secondly, introducing acidolysis tail gas into a gas inlet of the highest sub-reactor, and introducing titanium white waste acid into a liquid inlet of the lowest sub-reactor to react with the acidolysis tail gas;

conveying the titanium white waste acid reacted with the acidolysis tail gas into a primary sub-reactor, and reacting the titanium white waste acid with the acidolysis tail gas;

step four, when titanium white waste acid exists in the highest sub-reactor, conveying the titanium white waste acid to each sub-reactor is suspended;

step five, the titanium white waste acid in each sub-reactor is self-circulated and continuously reacts with the introduced acidolysis tail gas, and the concentration of the titanium white waste acid in the highest sub-reactor is monitored in real time on line;

and step six, when the mass concentration of the titanium white waste acid in the highest-level sub-reactor is detected to be 25% -30%, judging the titanium white waste acid to be a qualified product, suspending self-circulation, and conveying the qualified titanium white waste acid into a qualified product storage tank.

Further, the sub-reactors are leaching towers, venturi tubes or spraying pipelines.

Further, the sub-reactors comprise reaction cylinders and waste acid storage tanks; the bottom of the reaction cylinder is provided with an acidolysis tail gas inlet, and the top of the reaction cylinder is provided with an acidolysis tail gas outlet; a waste acid spraying device with a nozzle facing the bottom of the reaction cylinder is arranged in the reaction cylinder, and a liquid inlet of the waste acid spraying device is connected with a liquid inlet of the reaction cylinder through a pipeline; a liquid inlet of the reaction cylinder is connected with a liquid outlet of a waste acid storage tank through a circulating pump, and a liquid inlet of the waste acid storage tank is connected with a liquid outlet of the reaction cylinder; the liquid outlet of the reaction cylinder of the sub-reactor at the highest level is connected with the liquid inlet of the qualified product storage tank through a liquid outlet pump; the acidolysis tail gas inlet is the gas inlet of the sub-reactor, and the acidolysis tail gas outlet is the gas outlet of the sub-reactor; the liquid inlet of the reaction cylinder is the liquid inlet of the sub-reactor, and the liquid outlet of the reaction cylinder is the liquid outlet of the sub-reactor.

Furthermore, the number of the waste acid spraying devices is at least two, and the waste acid spraying devices are distributed at intervals along the height direction of the reaction cylinder.

Further, a gas distribution plate is arranged in the reaction cylinder, and at least two through holes which are uniformly distributed are formed in the gas distribution plate.

Furthermore, the number of the gas distribution plates is equal to that of the waste acid spraying devices, and each gas distribution plate is respectively positioned at the lower side of each waste acid spraying device.

Further, in the second step, the temperature of the introduced acidolysis tail gas is 150-250 ℃.

Further, the main component of the acidolysis tail gas is H₂O、H₂S、SO₂And SO₃。

Further, the acidolysis tail gas is tail gas generated in the acidolysis process of preparing titanium dioxide by a sulfuric acid method.

Further, the method also comprises a seventh step; and step seven, repeating the step two to the step six, and circulating in the way to realize continuous production.

The invention has the beneficial effects that: through selecting the gas-liquid reactor as treatment facility including at least three sub-reactor that sets up according to the rank from low to high in proper order in grades, make titanium white spent acid fully react with acidolysis tail gas, not only can effectively improve production efficiency, and both can absorb acid mist and sulphide through making the titanium white spent acid promote concentration in the acidolysis tail gas, can produce more vapor through the heat that absorbs acidolysis tail gas again, and take away by acidolysis tail gas and further promote concentration, compare with current distillation concentration processing mode, equipment input and energy consumption are all lower.

Drawings

FIG. 1 is a schematic view of the structure of a gas-liquid reactor in accordance with the present invention;

labeled as: the device comprises a sub-reactor 100, a reaction cylinder 110, an acidolysis tail gas inlet 111, an acidolysis tail gas outlet 112, a waste acid spraying device 113, a pipeline 114, a gas distribution plate 115, a waste acid storage tank 120, an acid concentration online detector 121, a circulating pump 130, a flow regulating valve 140, a liquid feeding pump 210, a liquid feeding valve 220, a qualified product storage tank 300, a liquid discharging pump 310 and a liquid discharging valve 320.

Detailed Description

The invention will be further explained with reference to the drawings.

The method for improving the concentration of titanium white waste acid comprises the following steps:

step one, selecting a gas-liquid reactor comprising at least three sub-reactors 100 which are arranged in a grading manner from low to high in sequence as processing equipment, connecting an air outlet of the sub-reactor 100 with an air inlet of the sub-reactor 100 of the next stage, and connecting an liquid outlet of the sub-reactor 100 with a liquid inlet of the sub-reactor 100 of the previous stage;

secondly, introducing acidolysis tail gas into the gas inlet of the sub-reactor 100 at the highest level, and introducing titanium white waste acid into the liquid inlet of the sub-reactor 100 at the lowest level to react with the acidolysis tail gas;

conveying the titanium white waste acid reacted with the acidolysis tail gas into a primary sub-reactor 100, and reacting the titanium white waste acid with the acidolysis tail gas;

step four, when titanium white waste acid exists in the sub-reactor 100 at the highest level, the titanium white waste acid is temporarily conveyed to each sub-reactor 100;

step five, the titanium white waste acid in each sub-reactor 100 is self-circulated and continuously reacts with the introduced acidolysis tail gas, and the concentration of the titanium white waste acid in the highest sub-reactor 100 is monitored in real time on line;

step six, when the mass concentration of the titanium white waste acid in the highest-level sub-reactor 100 is detected to be 25% -30%, the titanium white waste acid is judged to be a qualified product, self-circulation is suspended, and the qualified titanium white waste acid is conveyed into a qualified product storage tank 300.

The method for improving the concentration of the titanium white waste acid comprises the step of selecting a gas-liquid reactor comprising at least three sub-reactors 100 which are arranged in a grading manner from low to high in sequence as a treatment device, so that the titanium white waste acid and the acidolysis tail gas are fully reacted, the production efficiency can be effectively improved, the concentration can be improved by absorbing acid mist and sulfide in the acidolysis tail gas through the titanium white waste acid, more water vapor can be generated by absorbing heat of the acidolysis tail gas, the concentration is further improved by taking away the acidolysis tail gas, and compared with the existing distillation concentration treatment mode, the equipment investment and the energy consumption are lower.

Wherein the acidolysis tail gas mainly contains water vapor, acid mist and sulfide, and the main component is H₂O、H₂S、SO₂And SO₃(ii) a Acidolysis of titanium dioxide prepared by sulfuric acid methodThe tail gas generated in the process can improve the concentration of the titanium dioxide waste acid. The concentration of titanium dioxide spent acid in the top sub-reactor 100 is monitored on-line in real time, typically by an acid concentration on-line detector 121; the acid concentration on-line detector 121, also called an intelligent on-line concentration meter or an on-line concentration transmitter, is a device for continuously measuring the concentration of liquid on line, and can be directly used in the industrial production process.

The sub-reactor 100 is mainly used for reacting titanium dioxide waste acid with acidolysis tail gas and performing heat and mass exchange, which may be various, for example: a leaching tower, a venturi tube, or a spray line.

Preferably, as shown in fig. 1, the sub-reactor 100 includes a reaction cylinder 110 and a waste acid storage tank 120; the bottom of the reaction cylinder 110 is provided with an acidolysis tail gas inlet 111, and the top of the reaction cylinder 110 is provided with an acidolysis tail gas outlet 112; a waste acid spraying device 113 with a nozzle facing the bottom of the reaction cylinder 110 is arranged in the reaction cylinder 110, and a liquid inlet of the waste acid spraying device 113 is connected with a liquid inlet of the reaction cylinder 110 through a pipeline 114; a liquid inlet of the reaction cylinder 110 is connected with a liquid outlet of the waste acid storage tank 120 through a circulating pump 130, and a liquid inlet of the waste acid storage tank 120 is connected with a liquid outlet of the reaction cylinder 110; an acidolysis tail gas outlet 112 of the reaction cylinder 110 of the sub-reactor 100 is connected with an acidolysis tail gas inlet 111 of the reaction cylinder 110 of the sub-reactor 100 at the next stage; the liquid outlet of the reaction cylinder 110 of the sub-reactor 100 is connected with the liquid inlet of the reaction cylinder 110 of the sub-reactor 100 at the previous stage thereof through a liquid feeding pump 210, and the liquid outlet of the reaction cylinder 110 of the sub-reactor 100 at the highest stage is connected with the liquid inlet of the qualified product storage tank 300 through a liquid discharging pump 310; the acidolysis tail gas inlet 111 is the gas inlet of the sub-reactor 100, and the acidolysis tail gas outlet 112 is the gas outlet of the sub-reactor 100; the liquid inlet of the reaction cylinder 110 is the liquid inlet of the sub-reactor 100, and the liquid outlet of the reaction cylinder 110 is the liquid outlet of the sub-reactor 100.

The sub-reactor 100 comprises a reaction cylinder 110 and a waste acid storage tank 120, wherein the reaction cylinder 110 and the waste acid storage tank 120 are circularly connected through a circulating pump 130; can make the titanium dioxide spent acid that lets in among the sub-reactor 100 circulate in reaction cylinder 110 and spent acid storage tank 120, constantly spray from last down through spent acid spray set 113 in reaction cylinder 110, with from the last acidolysis tail gas that flows up from the lower in letting in reaction cylinder 110 from acidolysis tail gas import 111 fully reacts, make the titanium dioxide spent acid both can absorb acid mist and the sulphide lifting concentration in the acidolysis tail gas, can produce more vapor and take away by acidolysis tail gas through the heat of absorbing acidolysis tail gas again and promote the concentration.

The reaction cylinder 110 is mainly used for fully reacting titanium dioxide waste acid with acidolysis tail gas and exchanging heat and mass; the reaction cylinder 110 is generally vertically arranged, and the cross section of the reaction cylinder can be in various structures such as a circle, a rectangle, a polygon or an abnormity; the acidolysis tail gas inlet 111 is used for introducing acidolysis tail gas, and the acidolysis tail gas inlet 111 of the reaction cylinder 110 of the highest sub-reactor 100 is usually connected with an acidolysis tail gas source; the acidolysis tail gas outlet 112 is used for discharging acidolysis tail gas after reaction, and the acidolysis tail gas outlet 112 of the reaction cylinder 110 of the sub-reactor 100 at the lowest level is generally connected with a tail gas treatment device. The waste acid spraying device 113 is used for spraying titanium dioxide waste acid, which can be various, and is preferably a shower head.

In order to disperse the titanium white waste acid in the reaction cylinder 110 sufficiently, as shown in fig. 1, at least two waste acid spraying devices 113 are arranged and distributed at intervals along the height direction of the reaction cylinder 110.

On the basis, in order to make the introduced acidolysis tail gas more dispersed, a gas distribution plate 115 is further arranged in the reaction cylinder 110, and at least two through holes which are uniformly distributed are formed in the gas distribution plate 115.

Preferably, the number of the gas distribution plates 115 is equal to the number of the waste acid spray devices 113, and each gas distribution plate 115 is positioned at the lower side of each waste acid spray device 113.

In order to effectively control the process of the titanium dioxide waste acid and the acidolysis tail gas in the sub-reactor 100 for more sufficient reaction and efficiency, as shown in fig. 1, a flow control valve 140 is disposed on the connection between the circulation pump 130 and the liquid outlet of the waste acid storage tank 120. The flow control valve 140 is generally electrically connected to the controller, and the controller controls the operation state thereof.

The gas-liquid reactor generally further comprises an acidolysis tail gas source and a titanium dioxide waste acid source, wherein the acidolysis tail gas source is connected with the acidolysis tail gas inlet 111 of the reaction cylinder 110 through an induced draft fan, and the titanium dioxide waste acid source is connected with the liquid inlet of the reaction cylinder 110 of the lowest-level sub-reactor 100 through a titanium dioxide waste acid pump. The acidolysis tail gas source may be various, for example: the equipment used in the acidolysis process for preparing titanium dioxide by a sulfuric acid method. The titanium white waste acid source is generally equipment for preparing titanium dioxide by a sulfuric acid method. The induced draft fan is used for regulating and controlling the flow velocity of the acidolysis tail gas so as to improve the reaction sufficiency of the titanium dioxide waste acid and the acidolysis tail gas in the reaction cylinder 110 and take away the effect of water vapor.

In order to facilitate the titanium white waste acid in the next sub-reactor 100 to be conveyed into the previous sub-reactor 100, as shown in fig. 1, a liquid conveying valve 220 is disposed on a connection between the liquid conveying pump 210 and the liquid inlet of the reaction cylinder 110.

In order to facilitate the transfer of the qualified titanium dioxide waste acid in the highest-level sub-reactor 100 into the qualified product storage tank 300, as shown in fig. 1, a liquid outlet valve 320 is provided on the connection between the liquid outlet pump 310 and the liquid inlet of the qualified product storage tank 300.

In order to facilitate online real-time monitoring of the titanium dioxide waste acid concentration in the highest sub-reactor 100, as shown in fig. 1, an acid concentration online detector 121 is disposed in the waste acid storage tank 120 of the highest sub-reactor 100.

Preferably, the gas-liquid reactor further comprises a controller, and the controller is electrically connected with the acid concentration online detector 121, the liquid feeding pump 210, the liquid feeding valve 220, the liquid discharging pump 310 and the liquid discharging valve 320 respectively; when the acid concentration on-line detector 121 detects that the concentration of titanium dioxide waste acid in the waste acid storage tank 120 reaches a set range, a signal is fed back to the controller, the controller first controls the liquid outlet valve 320 to open, controls the liquid outlet pump 310 to pump titanium dioxide waste acid in the highest-level sub-reactor 100 to the qualified product storage tank 300, then controls the liquid outlet valve 320 to close, controls the liquid inlet valve 220 to open, and controls the liquid inlet pump 210 to pump titanium dioxide waste acid in the next-level sub-reactor 100 to the previous-level sub-reactor 100. Through adopting the controller to control, can improve this a gas-liquid reactor's for improving titanium white waste acid concentration degree of automation, reduce artifical intensity of labour, practice thrift the human cost.

In order to improve the sufficiency of the reaction between the titanium white waste acid and the acidolysis tail gas and the amount of generated water vapor, the temperature of the acidolysis tail gas introduced in the second step is preferably 150-250 ℃.

As a preferred scheme of the invention, the method for improving the concentration of the titanium white waste acid further comprises a seventh step;

and step seven, repeating the step two to the step six, and circulating in the way to realize continuous production.