阅读说明：本技术 一种酸洗废液制备铁盐、羟基氧化铁的方法 (Method for preparing ferric salt and iron oxyhydroxide from pickling waste liquid ) 是由 宋德生 吴勇基 侯汝龙 蓝立财 江仲厅 丁德才 肖晋宜 于 2021-10-30 设计创作，主要内容包括：本发明属于环保技术领域,提供一种酸洗废液制备铁盐、羟基氧化铁的方法,包括以下步骤：采用含酸洗废液为原料,与含单质铁物料进行置换反应,过滤得到高纯度的亚铁溶液；再将所述的亚铁溶液依次进行氧气氧化、过滤分离,获得铁盐产物及羟基氧化铁。本发明方法采用酸洗废液为原料制备铁盐、羟基氧化铁,不仅对危险废物得到资源化利用,而且达到以废治废、变废为宝的效果；本发明方法具有工艺简单、操作方便、成本费用低特点,容易实现工业化应用。(The invention belongs to the technical field of environmental protection, and provides a method for preparing ferric salt and hydroxyl ferric oxide from pickling waste liquid, which comprises the following steps: the method comprises the following steps of (1) performing a displacement reaction on acid-containing washing waste liquid serving as a raw material and a material containing simple substance iron, and filtering to obtain a high-purity ferrous solution; and then sequentially carrying out oxygen oxidation, filtration and separation on the ferrous solution to obtain an iron salt product and ferric oxyhydroxide. The method adopts the pickling waste liquid as the raw material to prepare the ferric salt and the ferric hydroxide, thereby not only realizing resource utilization of hazardous wastes, but also achieving the effects of treating wastes with processes of wastes against one another and changing wastes into valuables; the method has the characteristics of simple process, convenient operation and low cost, and is easy to realize industrial application.)

1. The method for preparing the ferric salt and the ferric hydroxide from the pickling waste liquid is characterized by comprising the following steps of:

the method comprises the following steps of (1) performing a displacement reaction on acid-containing washing waste liquid serving as a raw material and a material containing simple substance iron, and filtering to obtain a high-purity ferrous solution; and then sequentially carrying out oxygen oxidation, filtration and separation on the ferrous solution to obtain an iron salt product and ferric oxyhydroxide.

2. The method for preparing iron salt and iron oxyhydroxide from the pickling waste liquid according to claim 1, wherein the pickling waste liquid is a hydrochloric acid pickling waste liquid.

3. The method for preparing iron salt and iron oxyhydroxide from the pickling waste liquid according to claim 1, wherein the iron salt product is ferric chloride.

4. The method for preparing iron salt and iron oxyhydroxide from the pickling waste liquid according to claim 1, wherein the material containing elemental iron is one or more of iron powder, iron sheet, ring iron and iron block.

5. The method for preparing iron salt and iron oxyhydroxide from the pickling waste liquid according to claim 1, wherein the reaction temperature of the oxygen oxidation process is 70-100 ℃.

6. The method for preparing iron salt and iron oxyhydroxide from the pickling waste liquid according to claim 1, wherein the reaction pressure of the oxygen oxidation process is 0.07-0.3 MPa.

7. The method for preparing iron salt and iron oxyhydroxide from pickling waste liquid according to claim 1, wherein the oxygen oxidation process further comprises adding a catalyst in an amount of 0.0-0.03% by mass of the material.

8. The method for preparing iron salt and iron oxyhydroxide from the pickling waste liquid according to claim 7, wherein the catalyst is nitric acid.

9. The method for preparing iron salt and iron oxyhydroxide from the pickling waste liquid according to claim 1, wherein the reaction device adopted in the oxygen oxidation process is batch type or continuous type, and the reaction time is 1-6 h.

10. The method for preparing iron salt and iron oxyhydroxide from acid pickling waste liquid according to claim 9, wherein the stirring speed of the reaction device is 100-1000 r/min.

Technical Field

The invention belongs to the technical field of environmental protection, and particularly relates to a method for preparing ferric salt and iron oxyhydroxide from pickling waste liquid.

Background

The iron oxyhydroxide is an important industrial material, has wide application in the aspects of magnetic materials, catalysis, pigments, ceramics, rubber, biomedical treatment, heavy metal removal, sewage treatment and the like, and has excellent application prospect. The waste steel pickling liquid is produced by using hydrochloric acid solution to clean oxide on the surface of steel parts in the steel processing industry. The improper treatment of the pickling waste liquid not only seriously pollutes the ecological environment, but also causes great resource waste.

Therefore, the development of a process for producing iron salt and iron oxyhydroxide by using the pickling waste liquid has great practical value significance. The process not only applies the reduction, the resource utilization and the harmlessness of the dangerous waste of the pickling waste liquid, but also develops the green circular economy of treating the waste by the waste and changing the waste into the valuable.

In the prior art, the preparation of iron oxyhydroxide is mainly carried out by mixing Fe²⁺Mixing the metal salt solution and the alkali solution, controlling the pH and the temperature of the system, oxidizing by adopting oxygen-containing gas, filtering and drying to obtain a finished product of the hydroxyl ferric oxide. Although the method can produce and prepare the iron oxyhydroxide in large batch and stably, the method adopts the alkali solution as the raw material to adjust the pH value of the solution, introduces salt impurities and has high raw material cost; fe²⁺The precipitation speed is slow, the time consumption is long, and the reaction efficiency is low.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a process method for preparing ferric salt and hydroxyl ferric oxide by using pickling waste liquid.

The technical scheme of the invention is as follows:

the method for preparing the ferric salt and the ferric hydroxide from the pickling waste liquid is characterized by comprising the following steps of:

s1, adding a material containing simple substance iron into the pickling waste liquid to obtain a high-purity ferrous solution.

In one embodiment of the invention, the material containing the elementary substance iron is added into the pickling waste liquid, and the material containing the elementary substance iron reacts with hydrochloric acid in the pickling waste liquid to reduce the acidity of the solution, generate ferrous chloride and improve the mass fraction of iron in the material; along with the reduction of acidity in the raw materials, the material containing the simple substance iron can also perform oxidation reduction reaction with metal ions such as copper ions, nickel ions, ferric ions, hexavalent chromium ions and the like in the material, impurity metal ions are reduced to form the simple substance, meanwhile, when the pH value of the trivalent chromium ions is more than or equal to 3, chromium (III) hydroxide precipitate can be formed, and the high-purity ferrous solution can be obtained through separation after filtration. The step mainly has the effects of reducing impurities of the raw materials and improving the quality and the purity.

S2, further carrying out oxygen oxidation and filtering separation on the obtained high-purity ferrous solution to obtain an iron salt product and hydroxyl ferric oxide respectively.

In one embodiment of the invention, the ferrous solution obtained by replacing and removing impurities from the pickling waste liquid with elementary substance iron is placed in a reaction kettle, the stirring speed is set to be 100-1000r/min, the reaction temperature is 70-100 ℃, the reaction pressure is 0.07-0.3MPa, the adding amount of the catalyst nitric acid is 0.0-0.03 percent of the mass of the material, the reaction time is 1-6h, and after the reaction is finished, ferric salt and hydroxyl ferric oxide products can be obtained through filtering and separation.

In the invention, a material containing simple substance iron is added into the pickling waste liquid to obtain a high-purity ferrous solution. On one hand, the simple substance iron in the material can replace and remove impurity metal ions in the pickling waste liquid, simultaneously reduce the acidity in the solution, improve the iron content in the raw material liquid, and lead the heavy metal in the material to be hydrolyzed, precipitated and removed; improve the quality fraction of iron in the material, reduce impurities and further improve the product purity.

And further carrying out oxygen oxidation and filtering separation on the obtained high-purity ferrous solution to obtain an iron salt product and ferric oxyhydroxide respectively. The reaction process has high reaction speed; alkali solution is not required to be added, so that the production cost is reduced; the process has the advantages of simple process, convenient operation and easy industrial production.

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

(1) the method adopts the pickling waste liquid as the raw material to prepare the ferric salt and the ferric hydroxide, thereby not only realizing resource utilization of hazardous wastes, but also achieving the effects of treating wastes with processes of wastes against one another and changing wastes into valuables;

(2) according to the invention, the pickling waste liquid is subjected to displacement impurity removal, and meanwhile, the use of alkali solution for adjusting pH is avoided, so that on one hand, a product with higher purity and better quality can be obtained; on the other hand, the reaction speed is high, the process is simple, and the raw material cost is low;

(3) the method has the characteristics of simple process, convenient operation and low cost, and is easy to realize industrial application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the detailed description and specific examples, while indicating the scope of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

Example 1

A method for preparing iron salt and iron oxyhydroxide from pickling waste liquid comprises the following steps:

1000g of hydrochloric acid pickling waste liquor (Fe: 8.68%, Fe)²⁺: 8.44%, HCl: 4.73%) was charged with an appropriate amount of reduced iron powder, and after the reaction was completed, 1074g of a ferrous chloride solution (Fe: 14.96% of Fe²⁺: 14.96%, HCl: 0.01 percent) of the solution is put into an oxidation reaction kettleAdjusting the stirring speed to be 100r/min, the reaction temperature to be 90 ℃, adding no catalyst, introducing oxygen, keeping the pressure of the reaction kettle at 0.15 MPa, reacting for 4 hours, and filtering after the reaction is finished to obtain 927g of ferric trichloride and 85g of iron oxyhydroxide (dry basis).

Example 2

A method for preparing iron salt and iron oxyhydroxide from pickling waste liquid comprises the following steps:

1000g of hydrochloric acid pickling waste liquor (Fe: 9.30%, Fe)²⁺: 8.90%, HCl: 2.37%) was added with an appropriate amount of iron sheet, and after the reaction was completed, it was filtered to obtain 1039g of ferrous chloride solution (Fe: 12.72% of Fe²⁺: 12.72%, HCl: 0.01 percent) of iron trichloride, and 70g of iron oxyhydroxide (dry basis) can be obtained by placing the mixture into an oxidation reaction kettle, adjusting the stirring speed to be 500r/min, the reaction temperature to be 75 ℃, adding 0.5g of catalyst nitric acid, introducing oxygen, keeping the pressure of the reaction kettle at 0.3MPa, reacting for 3 hours, and filtering after the reaction is finished.

Example 3

A method for preparing iron salt and iron oxyhydroxide from pickling waste liquid comprises the following steps:

1000g of hydrochloric acid pickling waste liquor (Fe: 12.35%, Fe2 +: 11.55%, HCl: 3.17%) is added into a proper amount of ring iron, after the reaction is finished, 1040g of ferrous chloride solution (Fe: 16.38%, Fe: 3.17%) is obtained by filtration²⁺: 16.38%, HCl: 0.01%) of the iron trichloride solution is put into an oxidation reaction kettle, the stirring speed is adjusted to 600r/min, the reaction temperature is 70 ℃, oxygen is introduced, the pressure of the reaction kettle is kept to be 0.10MPa, the reaction time is 5 hours, and after the reaction is finished, filtration is carried out, so that 973.2g of the iron trichloride and 90.3g of the iron oxyhydroxide (dry basis) can be obtained.

Example 4

A method for preparing iron salt and iron oxyhydroxide from pickling waste liquid comprises the following steps:

1000g of hydrochloric acid pickling waste liquid (Fe: 7.88%, Fe2 +: 7.52%, HCl: 1.48%) is placed in an oxidation reaction kettle, the stirring speed is adjusted to 700r/min, the reaction temperature is 80 ℃, oxygen is introduced, the pressure of the reaction kettle is kept to be 0.09MPa, the reaction time is 4 hours, and after the reaction is finished, filtration is carried out, so that 983.9g of ferric trichloride and 27.4g of iron oxyhydroxide (dry basis) can be obtained.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art. It should be noted that the technical features not described in detail in the present invention can be implemented by any prior art in the field.