Method of manufacturing ferrous sulfate by solation treatment of ferrous material

Abstract

The present invention relates to a method of manufacturing ferrous sulfate by solation treatment of a ferrous material, the method comprising: a raw material preparation step of preparing a ferrous material as a raw material of ferrous sulfate; a pre-processing step of grinding the ferrous material prepared in the raw material preparation step to a size of 0.1-100,000 micrometers (μm) to form fine iron particles; a solation treatment step of mixing the fine iron particles obtained in the pre-processing step with a solvent to disperse the fine iron particles in the solvent liquid in a colloidal and suspension state; and a chemical reaction step of mixing the liquid in which the fine iron particles have undergone solation treatment, with sulfuric acid or waste sulfuric acid to cause a chemical reaction, thereby producing ferrous sulfate in liquid phase. The method enables mass production with a high yield, and thus can provide ferrous sulfate at a lower cost.

Description

Method for producing ferrous sulfate by sol treatment of iron material

[0001] The present invention relates to a method for producing ferrous sulfate by sol-processing an iron material, and more particularly, to a method for producing ferrous sulfate by sol-processing an iron material, which enables mass production of ferrous sulfate with a high yield by mixing sulfuric acid with an iron-containing material (hereinafter referred to as “iron material”) and reacting the mixture, while the iron material is in a sol-processed state, with sulfuric acid.

[0002] Generally, ferrous sulfate (FeSO4) is a substance that is created through a reaction when iron and sulfuric acid are combined and exists in the form of heptahydrate (7H2O).

[0003] This ferrous sulfate heptahydrate (FeSO4·7H2O) (hereinafter referred to as 'ferrous sulfate') is used as a cement additive by mixing it with cement to reduce chromium (VI) contained in cement, which is harmful to the human body, to chromium (III) and is also used as a coagulant for sludge produced by mixing it with slaked lime during water treatment. It is also used in health supplements to supplement iron.

[0004] Looking at the method currently being used to manufacture the above-mentioned ferrous sulfate, the method of manufacturing ferrous sulfate through a reaction of simply mixing sulfuric acid or waste sulfuric acid with general iron or solid sludge containing iron components is widely known through various experimental results.

[0005] However, the method of simply mixing sulfuric acid with iron or iron-containing solid sludge as described above has a low chemical collision frequency of the reaction, so although it is possible to produce a small amount of ferrous sulfate with uniform quality, it is difficult to produce it in large quantities, and thus there is a problem that it is difficult to lower the manufacturing cost of ferrous sulfate.

[0006] As a prior art for such a method for manufacturing ferrous sulfate, there is Korean Patent Publication No. 10-2022-0087915 entitled 'Method for Manufacturing Ferrous Sulfate' (hereinafter referred to as 'Patent Document 1') disclosed in the patent document of the prior art document below.

[0007] Patent Document 1 below is a method for producing ferrous sulfate that does not require a separate crystallization step or filtration step by lowering the water content and can be used as a cement additive without additional processes. However, even with this method, there is a problem that it is difficult to mass-produce ferrous sulfate.

[0008] [Prior Art Literature]

[0009] [Patent Document]

[0010] (Patent Document 1) Republic of Korea Patent Publication No. 10-2022-0087915, 'Method for Manufacturing Ferrous Sulfate'

[0011] The present invention was developed to improve the above problems, and the purpose of the present invention is to provide a method for producing ferrous sulfate by sol-processing of iron material, which enables mass production of ferrous sulfate heptahydrate (hereinafter referred to as 'ferrous sulfate') by first sol-processing iron material of general iron powder or steelmaking sludge and then mixing sulfuric acid or waste sulfuric acid to maximize the yield through a uniform chemical reaction.

[0012] The present invention, in order to achieve the above object, is characterized by a method for producing ferrous sulfate by sol-processing of an iron material, comprising: a raw material preparation step of preparing an iron material containing iron as a raw material for ferrous sulfate; a pretreatment step of crushing the iron material prepared in the raw material preparation step into a fine size to produce iron fine particles; a sol-processing step of mixing a solvent with the iron fine particles so that the iron fine particles are dispersed in a colloidal and suspended state in a liquid solvent; and a chemical reaction step of mixing waste sulfuric acid or sulfuric acid into a liquid in which the iron fine particles have been sol-processed so that ferrous sulfate is produced in a liquid phase through a chemical reaction.

[0013] At this time, the above-mentioned iron material is characterized by being one or two or more of steel sludge made by settling steel particles by spraying water in a steel factory, iron scrap which is scrap iron, mill scale which is an oxide layer produced during the rolling or heat treatment process of steel products, iron ore, and iron powder.

[0014] And the above-mentioned SOL treatment step includes a dispersant added when mixing iron fine particles and a solvent, and is characterized by being an emulsion state in which the colloid and suspension are mixed and sol-ized into a solution.

[0015] In addition, if it is necessary to store the prepared iron material for a long period of time after performing the above raw material preparation step, an antioxidant is added to prevent the iron material from being oxidized.

[0016] The method for producing ferrous sulfate of the present invention first sol-treats the ferrous material (material containing iron) before mixing sulfuric acid or waste sulfuric acid into the iron material, thereby increasing the frequency of chemical collisions and allowing a chemical reaction by sulfuric acid or waste sulfuric acid to occur uniformly, thereby enabling mass production with a high yield, and thus has the effect of providing ferrous sulfate at a lower price.

[0017] And, even though steelmaking sludge, iron scrap, and mill scale, which can be called iron waste, are utilized and waste sulfuric acid is used, the yield of iron sulfate can be increased through liquid-liquid reaction through sol treatment of iron materials, which has the effect of increasing the production of iron sulfate.

[0018] Figure 1 is a block diagram showing an example of the ferrous sulfate manufacturing process of the present invention.

[0019] Figure 2 is a block diagram showing another example of the ferrous sulfate manufacturing process of the present invention.

[0020] [Explanation of symbols]

[0021] S100: Raw material preparation stage

[0022] S200: Preprocessing stage

[0023] S300: Sol (SOL) processing stage

[0024] S400: Chemical reaction stage

[0025] The following description of the present invention is merely an example for structural and functional explanation, and therefore the scope of the present invention should not be construed as being limited by the examples specified in the text.

[0026] That is, since the embodiments can be modified in various ways and can take various forms, the scope of the present invention should be understood to include equivalents that can realize the technical idea.

[0027] In addition, the purpose or effect presented in the present invention does not mean that a specific embodiment must include all of them or include only such effects, and therefore, the scope of the present invention should not be understood as being limited thereby.

[0028] The preferred technical configuration and operation for carrying out the present invention are described in more detail with reference to the attached drawings as follows.

[0029] FIG. 1 is a block diagram showing one example of a process for manufacturing ferrous sulfate according to the present invention, and FIG. 2 is a block diagram showing another example of a process for manufacturing ferrous sulfate according to the present invention.

[0030] As illustrated herein, the method for manufacturing ferrous sulfate of the present invention is characterized by being composed of <raw material preparation step>, <pretreatment step>, <sol treatment step>, and <chemical reaction step> described below.

[0031] <Raw material preparation stage>

[0032] The raw material preparation stage (S100) is the stage of preparing iron-containing iron material as a raw material for ferrous sulfate.

[0033] Here, the prepared iron material may be one or more of steel sludge, which is steel particles contained in the air at a steel plant that have been settled by water spraying, iron scrap, which is scrap iron, and mill scale, which is an oxide layer produced during the rolling or heat treatment process of steel products, which can be called iron waste.

[0034] In addition, any iron-containing material, such as mined iron ore or iron powder, may be used.

[0035] And in the raw material preparation step (S100), the moisture content of the iron material can be said to be approximately 20%. Therefore, if the prepared iron material raw material needs to be stored for a long period of time after performing the raw material preparation step above, it is advisable to store it by adding 0.01 to 0.1% of an antioxidant based on the prepared iron material before performing the pretreatment step below.

[0036] In this way, the process of iron oxide (Fe0) being oxidized to ferric oxide (Fe2O3) can be prevented, so that oxidation corrosion of the iron material can be effectively prevented even when the prepared iron material is stored for a long period of time.

[0037] <Preprocessing stage>

[0038] The preprocessing step (S200) is a step of crushing the iron material prepared in the above raw material preparation step into iron fine particles in a size of '0.1 to 100,000 micrometers (um)'.

[0039] Here, the above pretreatment step may include a 'pre-treatment step' in which the moisture of the iron material raw material prepared in the above raw material preparation step is first dried in a dryer.

[0040] That is, before performing the pretreatment step (S200), it is desirable to first perform a pretreatment step in which the steel sludge has a moisture content of about 20% in the raw material preparation step, so that the iron material is placed in a dryer and dried with hot air or a heater to make the moisture content 10% or less.

[0041] As described above, iron material dried to a moisture content of 10% or less can be turned into a normal product by performing a drying process on steel sludge corresponding to waste, and here, if the iron material to be pulverized is dried to a moisture content of 10% or less, it can be quickly and easily processed into considerably fine iron particles.

[0042] <SOL processing stage>

[0043] The SOL treatment step (S300) is a step in which a solvent is mixed with the iron particles obtained through the above pretreatment step so that the iron particles are dispersed in a colloid and suspension state in the solvent liquid.

[0044] The colloidal state is a state in which fine particles having a diameter of about 0.1 to 100,000 um (micrometers) are dispersed in a liquid, which are larger than ordinary molecules or ions, and the suspension state refers to a state in which solid particles larger than the particles in the colloidal state are dispersed.

[0045] In addition, the colloid and suspension states of the sol (SOL) treatment step (S300) are an emulsion state in which a colloid and suspension are mixed and sol-ized. In addition, the solvent in the sol (SOL) treatment step includes water, and the mixing ratio of the iron particles and the solvent is preferably 100 wt% of the iron particles and 20 wt% to 200 wt% of the solvent.

[0046] If the solvent content is less than 20 wt%, the iron particles are not effectively dispersed and tend to precipitate. If the solvent content exceeds 200 wt%, the product becomes too dilute, making it difficult to solidify. In addition, when mixing with the solvent, a dispersant may be added to increase the dispersion rate of the iron particles and prevent them from settling.

[0047] At this time, the mixing ratio of iron fine particles, solvent, and dispersant is preferably 100 wt% of iron fine particles, 20 wt% to 200 wt% of solvent, and 0.01 wt% to 5 wt% of dispersant, as this can prevent the settling of iron fine particles and disperse them in a jelly-like state without flow.

[0048] <Chemical reaction stages>

[0049] The chemical reaction step (S400) is a step in which the iron fine particles are sol-treated and dispersed in a liquid, and sulfuric acid or waste sulfuric acid is mixed in a ratio of 1:0.1 to 2 to produce ferrous sulfate in a liquid phase through a chemical reaction.

[0050] As described above, a liquid in which iron particles are well dispersed through sol treatment can improve mobility and at the same time increase chemical reactivity with sulfuric acid, thereby increasing yield.

[0051] At this time, if the ratio of the sulfuric acid or waste sulfuric acid is less than 0.1, the chemical reaction rate decreases, lowering the productivity of ferrous sulfate. If the ratio of the sulfuric acid or waste sulfuric acid is more than 2, drying is delayed, taking a long time to obtain ferrous sulfate, and residual sulfuric acid is generated, which lowers the performance of cement. Therefore, it is preferable to mix in the above ratio.

[0052] And after performing the above chemical reaction step, it is preferable to further perform a final drying step of obtaining ferrous sulfate by naturally drying or artificially drying the ferrous sulfate made into the liquid so that the moisture content is 30% or less.

[0053] The method for producing ferrous sulfate of the present invention, which produces ferrous sulfate by such a manufacturing process, utilizes iron wastes such as steelmaking sludge, iron scrap, and mill scale, and can significantly increase the yield of ferrous sulfate even when waste sulfuric acid is used.

[0054] In addition, by establishing a continuous mass production system, mass production is possible, and thus the production cost of ferrous sulfate, which is widely used across industries such as wastewater treatment and cement production, can be provided at the lowest possible price.

[0055] Although the invention made by the present inventor has been specifically described according to the above embodiments, it is obvious to a person having ordinary skill in the art that the present invention is not limited to the above embodiments and can be modified in various ways without departing from the spirit thereof.

Claims

1. Raw material preparation stage: a stage for preparing iron-containing iron material as a raw material for ferrous sulfate; Preprocessing step: a step of making iron fine particles by crushing the iron material prepared in the above raw material preparation step into a size of '0.1 to 100,000 micrometers (um)'; Solvent treatment step: a step of mixing a solvent into the iron particles of the above pretreatment step so that the iron particles are dispersed in a colloidal and suspension state in the solvent liquid; Chemical reaction step: a step of producing ferrous sulfate in a liquid phase by a chemical reaction of mixing sulfuric acid or waste sulfuric acid in a ratio of 1:0.1 to 2 in a liquid in which the iron fine particles have been sol-treated; The colloid and suspension states of the above SOL treatment step are A method for producing ferrous sulfate by sol-ization treatment of an iron material, characterized in that the iron material is in an emulsion state in which a colloid and a suspension are mixed and sol-ized.

2. In paragraph 1, The pretreatment step includes a pretreatment step of drying the moisture of the iron material in a dryer, A method for producing ferrous sulfate by sol treatment of an iron material, characterized in that it further includes a finishing step of naturally drying or drying liquid ferrous sulfate with warm air after performing a chemical reaction step to obtain ferrous sulfate.

3. In paragraph 1 or 2, Iron material, A method for manufacturing ferrous sulfate by sol treatment of an iron material characterized by one or more of steel sludge, which is steel particles settled by a water shower in a steel factory, iron scrap which is scrap iron, mill scale which is an oxide layer generated during the rolling or heat treatment process of iron products, iron ore, and iron powder.

4. In paragraph 2, The pretreatment step is to dry the iron material to a moisture content of 10% or less. A method for manufacturing ferrous sulfate by sol treatment of an iron material, characterized in that the ferrous sulfate obtained in the final drying step has a moisture content of 30% or less.

5. In paragraph 1 or 2, The SOL processing step is: Includes a dispersant that is added when mixing iron particles and a solvent. At this time, the mixing ratio of iron particles, solvent, and dispersant is A method for producing ferrous sulfate by sol treatment of an iron material, characterized in that 100 wt% of iron fine particles are mixed with 20 wt% to 200 wt% of a solvent and 0.01 wt% to 5 wt% of a dispersant in a weight ratio.

6. In paragraph 1 or 2, In cases where it is necessary to store iron materials prepared in the raw material preparation stage for a long period of time, A method for producing ferrous sulfate by sol treatment of an iron material, characterized in that an antioxidant is mixed in a mixing ratio of 0.01 to 0.1 wt% with respect to the iron material to prevent the process of iron oxide (Fe0) being oxidized to ferric oxide (Fe2O3).

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