阅读说明：本技术 一种低耗高效硅钢常化酸洗工艺及酸洗设备 (Low-consumption high-efficiency normalized pickling process and pickling equipment for silicon steel ) 是由 王耀 周云根 吴迪青 况群意 黎浩 许彦波 于 2021-07-23 设计创作，主要内容包括：本发明涉及一种低耗高效硅钢常化酸洗工艺及酸洗设备,其有效利用常化炉出口余温作为加热带钢的介质,使带钢与低温的酸液接触表面发生强烈的物理化学反应,快速酸洗剥离表层粗大的氧化铁皮,降低酸洗系统的酸液温度,通过调控溶液氧化还原特性提高酸洗效率去除残留的铁橄榄石,节约了能耗,同时取消了高投资高运行成本的抛丸工艺,实现了低耗高效硅钢常化酸洗的目的。(The invention relates to a low-consumption high-efficiency silicon steel normalizing pickling process and pickling equipment, which effectively utilize the residual temperature at the outlet of a normalizing furnace as a medium for heating strip steel, so that the contact surface of the strip steel and low-temperature acid liquid generates strong physical and chemical reactions, the rough and large iron scales on the surface layer are quickly pickled and stripped, the temperature of the acid liquid of a pickling system is reduced, the pickling efficiency is improved by regulating and controlling the redox characteristics of the solution to remove residual fayalite, the energy consumption is saved, meanwhile, a shot blasting process with high investment and high operation cost is cancelled, and the purpose of low-consumption high-efficiency silicon steel normalizing pickling is realized.)

1. A low-consumption high-efficiency normalized pickling process for silicon steel is characterized by comprising the following steps:

step 1), controlling the temperature and preserving the heat of the strip steel from the cooling section of the normalizing furnace so as to enable the temperature of the strip steel to be higher than that of the pickling solution;

step 2), directly feeding the strip steel from the cooling section of the normalizing furnace into an acid washing tank for acid washing;

and 3) rinsing, drying and winding the pickled strip steel.

2. The normalized pickling process for low-consumption high-efficiency silicon steel as claimed in claim 1, wherein: in the step 1), the temperature of the strip steel from the cooling section of the normalizing furnace in the groove is higher than 100 ℃.

3. The normalized pickling process for low-consumption high-efficiency silicon steel as claimed in claim 1, wherein: in the step 1), the temperature control and heat preservation of the strip steel coming out of the cooling section of the normalizing furnace are realized by adjusting the circulation volume of the water jacket of the cooling section of the normalizing furnace and the temperature control of the heat preservation cavity.

4. The normalized pickling process for low-consumption high-efficiency silicon steel as claimed in claim 1, wherein: the pickling tank in the step 2) is formed by connecting a plurality of sub-tanks in series, the pickling solution is HCl with the concentration of 20-150 g/L, and meanwhile, the pickling solution contains Fe³⁺The pickling temperature of the pickling solution is 20-85 ℃.

5. The normalized pickling process for low-consumption high-efficiency silicon steel as claimed in claim 4, wherein: the pickling tank is composed of at least 3 sub tanks connected in series, and the oxidizing property of the pickling solution in the second sub tank from the beginning to the end is gradually improved.

6. The normalized pickling process for low-consumption high-efficiency silicon steel as claimed in claim 5, wherein: the pickling solution in the second sub-tank in the pickling tank is a reducing system, and the pickling solution in the last sub-tank is a strong oxidizing system.

7. The normalized pickling process for low-consumption high-efficiency silicon steel as claimed in claim 1, wherein: in the step 2), Fe in the pickling tank is regulated and controlled by on-line addition of polybasic weak acid and a circulating filtration mode²⁺And Fe³⁺Total iron content.

8. The normalized pickling process for low-consumption high-efficiency silicon steel as claimed in claim 1, wherein: in the step 2), Fe is regulated and controlled by adding an oxidant²⁺And Fe³⁺The proportion controls the redox properties of the pickling solution.

9. The utility model provides a low consumption high efficiency silicon steel normalizing pickling installation which characterized in that: comprises a strip steel transmission device, an uncoiler, a welding machine, a loop, a normalizing furnace, a heat preservation cavity, a multi-section pickling tank, a rinsing tank and a dryer which are sequentially arranged along the advancing direction of the strip steel.

10. The normalized pickling process for low-consumption high-efficiency silicon steel as claimed in claim 9, wherein: the automatic valve linkage type pickling system is characterized by further comprising a regulation and control system and an oxidation potential detection system, wherein the regulation and control system is connected with each pickling tank of the multiple sections of pickling tanks and is arranged, the oxidation-reduction characteristics of pickling media in the multiple sections of pickling tanks and the automatic valve linkage of the added oxidant are arranged, the oxidation potential detection system judges the oxidation-reduction characteristics of the pickling media by detecting the oxidation-reduction potential of acid liquor in the multiple sections of pickling tanks, and the oxidant is added into the corresponding pickling tanks of the multiple sections of pickling tanks by controlling the regulation and control system.

Technical Field

The invention relates to the technical field of strip steel surface cleaning, in particular to a low-consumption high-efficiency silicon steel normalized pickling process and pickling equipment.

Background

The surface quality of the strip steel is one of the key factors influencing the improvement of product performance. At present, the key process flow of the silicon steel normalizing pickling line is as follows: uncoiling, normalizing furnace, shot blasting machine, pickling tank, rinsing tank, drying and coiling. After the strip steel at the outlet of the normalizing furnace is cooled to be close to normal temperature through the water jacket, the strip steel enters a shot blasting machine to remove scales on the surface of the strip steel and then enters a pickling tank, and the residual iron scale is removed by utilizing the chemical reaction of hydrochloric acid. The silicon steel normalizing pickling process has low speed, low treatment efficiency and unsatisfactory descaling effect.

Aiming at the current situation that the surface scale treatment difficulty is high, the strip steel is generally pretreated by mechanical shot blasting of a plurality of throwing chambers at present and then enters a pickling tank, and the shot blasting treatment process becomes the standard configuration of a silicon steel normalizing pickling unit. The shot blasting treatment process mainly removes rough scale on the surface of the silicon steel, however, the shot blasting treatment process has the obvious defects of high investment cost, large floor area, high operation energy consumption, large maintenance amount, large environmental pollution and the like. In addition, the plate surface quality is not high after the acid washing by the existing configuration, and a small amount of fayalite with strong binding force still remains on the surface. Therefore, the conventional normalized pickling process needs to solve two problems: and (4) eliminating a shot blasting process and removing the residual striped fayalite on the surface after acid washing.

CN103122461A discloses a production method of cold-rolled oriented silicon steel without shot blasting and continuously passing through a pickling line, which cancels a shot blasting machine and removes iron oxide scales on the surface of the silicon steel by using acid liquor soaking and brush roll scrubbing. The patent only proposes to cancel shot blasting, has no relevant remedy or strengthening measure, is difficult to ensure the high-speed descaling effect, and the production method has low pickling efficiency and is not suitable for the industrialized high-speed normalized pickling process; meanwhile, the binding force of the Fe-Si olivine phase and the matrix exceeds 20MPa, the Fe-Si olivine phase is difficult to remove by brushing, the surface is easy to damage, and the roller consumption of the brush roller is high.

Disclosure of Invention

The invention aims to provide a normalized pickling process for low-consumption and high-efficiency silicon steel.

The specific scheme is as follows:

a low-consumption high-efficiency normalized pickling process for silicon steel comprises the following steps:

step 1), controlling the temperature and preserving the heat of the strip steel from the cooling section of the normalizing furnace so as to enable the temperature of the strip steel to be higher than that of the pickling solution;

step 2), directly feeding the strip steel from the cooling section of the normalizing furnace into an acid washing tank for acid washing;

and 3) rinsing, drying and winding the pickled strip steel.

Further, in the step 1), the temperature of the strip steel entering the cooling section of the normalizing furnace is higher than 100 ℃.

Further, in the step 1), the temperature control and the heat preservation of the strip steel coming out of the cooling section of the normalizing furnace are realized by adjusting the circulation volume of the water jacket of the cooling section of the normalizing furnace and the temperature control of the heat preservation cavity.

Further, the pickling tank in the step 2) is formed by connecting a plurality of sub-tanks in series, the pickling solution is HCl with the concentration of 20-150 g/L, and meanwhile, the pickling solution contains Fe³⁺The pickling temperature of the pickling solution is 20-85 ℃.

Furthermore, the pickling tank is composed of at least 3 sub-tanks connected in series, and the oxidizing property of the pickling solution in the sub-tank from the second beginning to the next is gradually improved.

Furthermore, the pickling solution in the second sub-tank in the pickling tank is a reducing system, and the pickling solution in the last sub-tank is a strong oxidizing system.

Further, in the step 2), Fe in the pickling tank is regulated and controlled by on-line addition of the weak polybasic acid and a circulating filtration mode²⁺And Fe³⁺Total iron content.

Further, in the step 2), Fe is regulated and controlled by adding an oxidant²⁺And Fe³⁺The proportion controls the redox properties of the pickling solution.

The invention also provides low-consumption high-efficiency silicon steel normalizing pickling equipment which comprises a strip steel transmission device, and an uncoiler, a welding machine, a loop, a normalizing furnace, a heat preservation cavity, a multi-section pickling tank, a rinsing tank and a dryer which are sequentially arranged along the advancing direction of the strip steel.

Furthermore, the device also comprises a regulation and control system and an oxidation potential detection, wherein the regulation and control system is connected with each pickling tank of the multi-section pickling tanks, the oxidation-reduction characteristics of the pickling medium in the multi-section pickling tanks are interlocked with an automatic valve for adding the oxidant, the oxidation potential detection judges the oxidation-reduction characteristics of the pickling medium by detecting the oxidation-reduction potential of the acid liquor in the multi-section pickling tanks, and the oxidant is added into the corresponding pickling tanks of the multi-section pickling tanks by controlling the regulation and control system.

Compared with the prior art, the low-consumption high-efficiency normalized pickling process for silicon steel provided by the invention has the following advantages: the low-consumption high-efficiency silicon steel normalized pickling process provided by the invention cancels a conventional shot blasting process, effectively utilizes the residual temperature at the outlet of the normalizing furnace to heat the strip steel, enables the strip steel to have a strong physical and chemical reaction with the contact surface of low-temperature acid liquor, rapidly pickle and strip rough iron scales on the surface layer, reduces the temperature of the acid liquor of a pickling system, improves the pickling efficiency by regulating and controlling the redox characteristics of the solution to remove residual fayalite, fully utilizes the residual temperature of the normalizing furnace as a medium for heating the strip steel, reduces the temperature of the acid liquor, saves the energy consumption, cancels a shot blasting process with high investment and high operation cost, and realizes the purpose of low-consumption high-efficiency silicon steel normalized pickling.

Drawings

FIG. 1 is a schematic view of a low-consumption high-efficiency silicon steel normalizing pickling apparatus.

Detailed Description

To further illustrate the various embodiments, the invention provides the accompanying drawings. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the embodiments. Those skilled in the art will appreciate still other possible embodiments and advantages of the present invention with reference to these figures. Elements in the figures are not drawn to scale and like reference numerals are generally used to indicate like elements.

The invention will now be further described with reference to the accompanying drawings and detailed description.

Example 1

The embodiment provides a low-consumption high-efficiency silicon steel normalizing pickling process, which utilizes the residual temperature of a normalizing furnace to improve the pickling efficiency, cancel a shot blasting machine and reduce the acid consumption, and simultaneously regulates and controls the acid liquor composition to improve the descaling efficiency so as to obtain the strip steel with high surface quality, and specifically comprises the following steps:

step 1), controlling the temperature and preserving the heat of the strip steel from the cooling section of the normalizing furnace so as to enable the temperature of the strip steel to be higher than that of the pickling solution. The temperature of the strip steel coming out of the cooling section of the normalizing furnace when entering the pickling tank is preferably higher than 100 ℃ so that the contact surface of the high-temperature strip steel and the low-temperature pickling solution can generate strong physical and chemical reactions to rapidly pickle and strip the rough and large iron scales on the surface layer, and a temperature compensating device can be added at the inlet of the pickling tank to compensate the temperature drop of the strip steel in the running process if necessary.

In this embodiment, the strip steel coming out of the cooling section of the normalizing furnace is controlled by adjusting the circulation volume of the water jacket and the temperature of the heat preservation cavity, so that the residual temperature of the normalizing furnace is utilized to the maximum extent, the temperature of the strip steel is controlled and preserved, and the purpose of reducing energy consumption is achieved.

And 2) directly feeding the strip steel with a certain temperature from the cooling section of the normalizing furnace into a pickling tank for pickling, wherein the strip steel is high in temperature and can generate strong physical and chemical reactions on the contact surface when being contacted with low-temperature acid liquor, so that the thick iron scales on the surface layer of the strip steel can be quickly pickled and stripped.

In the embodiment, the pickling tank is composed of 2-4 sub-tanks connected in series, the tank body is of a cone structure, the pickling solution is HCl with the concentration of 20-150 g/L, and meanwhile, the pickling solution contains Fe³⁺The pickling temperature of the pickling solution is 20-85 ℃, and Fe³⁺The content of the acid can adjust the oxidation-reduction characteristic of the acid washing solution so that the acid washing solution has the best acid washing effect on the strip steel.

Preferably, the pickling tank consists of at least 3 sub-tanks connected in series, and the Fe in the acid solution is regulated and controlled by a physical and/or chemical mode²⁺And Fe³⁺The proportion of (3) is that the oxidation property of the pickling solution in the sub-tank from the second to the last is gradually improved, and the preferable scheme is that the pickling solution in the second sub-tank is a reducing system, and the pickling solution in the last sub-tank is a strong oxidizing system.

Preferably, TongFe in the pickling tank is regulated and controlled by on-line addition of polybasic weak acid and circulating filtration²⁺And Fe³⁺Total iron content.

Preferably, the Fe is regulated and controlled by adding an oxidant²⁺And Fe³⁺The proportion controls the redox properties of the pickling solution. The final preferred acid tank acid properties are shown in table 2.

And 3) carrying out multi-stage rinsing, drying and rolling to obtain the high-surface-quality strip steel.

The low-consumption high-efficiency silicon steel normalized pickling process is suitable for cleaning a silicon steel normalized pickling unit, a conventional shot blasting process is omitted, the strip steel is heated by effectively utilizing the residual temperature at the outlet of a normalizing furnace, the strip steel is subjected to a strong physical and chemical reaction on the contact surface with low-temperature acid liquor, the rough and large iron scales on the surface layer are quickly pickled and stripped, the acid liquor temperature of a pickling system is reduced, the pickling efficiency is improved by regulating and controlling the redox characteristics of the solution, and the residual temperature of the normalizing furnace is fully utilized as a medium for heating the strip steel, the acid liquor temperature is reduced, the energy consumption is saved, meanwhile, the shot blasting process with high investment and high running cost is omitted, and the purpose of low-consumption high-efficiency silicon steel normalized pickling is achieved.

TABLE 1 table of contents of acid and metal ions in different pickling tanks under conventional pickling process

	Inlet pickling tank 6	Intermediate pickling tank 7	Outlet pickling tank 8
				HCl(g/l)	60	80	120
Fe2+(g/l)	120	100	40

The concentration of ferrous ions in an acid tank at the inlet of the conventional pickling solution is about 120g/L, the concentration of acid is reduced to 60g/L, the concentration is basically close to the concentration of waste acid, and the pickling efficiency is low; removing ferrous ions in the acid liquor by a complexing precipitation process and simultaneously generating free acid, namely maintaining the concentration of the ferrous ions to be less than 90g/L and the acid concentration to be more than 90g/L, so that the acid liquor is in higher acid washing activity; using Fe³⁺The reaction with the substrate peels off the attached fayalite.

TABLE 2 preferred acid concentration versus Metal ion concentration for different acid baths

	Inlet pickling tank 6	Intermediate pickling tank 7	Outlet pickling tank 8
				HCl(g/l)	90	100	120
Fe2+(g/l)	60	40	30
				Fe3+(g/l)	30	30	40

Example 2

Referring to fig. 1, the pickling apparatus for implementing the silicon steel normalizing pickling process of embodiment 1 includes a strip steel conveying device (not shown in the figure), and an uncoiler 1, a welder 2, a loop 3, a normalizing furnace 4, a heat preservation chamber 5, a 1# acid tank 6, a 2# acid tank 7, a 3# acid tank 8, a rinsing tank 9 and a dryer 10, which are sequentially arranged along the traveling direction of a strip steel 11.

The strip steel 11 is uncoiled by the uncoiler 1 and is conveyed to the subsequent process direction by the conveying device after being operated by the welding machine and the loop 3, the strip steel is firstly subjected to heat treatment by the normalizing furnace 4, the strip steel is output from the cooling section of the normalizing furnace 4 after the heat treatment is finished, the temperature of the strip steel coming out from the cooling section of the normalizing furnace is controlled by the circulation amount of the adjusting water jacket of the normalizing furnace and the temperature of the heat preservation cavity 5, the residual temperature of the normalizing furnace is utilized to the maximum extent, the temperature of the strip steel is higher than the temperature of pickling solution, preferably, the temperature of the strip steel entering the pickling tank is higher than 100 ℃, so that the contact surface of the high-temperature strip steel and the low-temperature pickling solution can generate strong physical and chemical reactions to rapidly pickle and strip large scale on the surface layer.

And after the hot high-temperature strip steel is subjected to acid cleaning in a No. 1 acid tank 6, a No. 2 acid tank 7 and a No. 3 acid tank 8 in sequence, the hot high-temperature strip steel enters a rinsing tank 9 and a hot air dryer 10 to be rinsed and air-dried to obtain the strip steel with high surface quality. Although fig. 1 shows only three acid tanks, i.e., the 1# acid tank 6, the 2# acid tank 7, and the 3# acid tank 8, the number of acid tanks is not limited to this, and the number of acid tanks may be increased or decreased depending on the number of stages of actual pickling.

In this embodiment, each acid tank is configured with an acid circulation tank 14, and the acid circulation tank 14 circulates acid with the corresponding acid tank through a circulation pump to ensure the concentration of the acid in the acid tank.

In this embodiment, the system further includes a regulation and control system 13 and an oxidation potential detection 12, the regulation and control system is connected to each pickling tank of the multiple pickling tanks, the oxidation-reduction characteristics of the pickling medium in each pickling tank and the automatic valve for adding the oxidant are arranged in a linkage manner, the oxidation potential detection 12 determines the oxidation-reduction characteristics of the pickling medium by detecting the oxidation-reduction potential of the acid liquid in each pickling tank, and controls the regulation and control system 13 to add the oxidant to the corresponding pickling tank of the multiple pickling tanks, so as to automatically control the oxidation-reduction characteristics of the pickling medium in each pickling tank of the multiple pickling tanks, and further ensure the cleaning effect and consistency of the strip steel.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.