KR102507924B1 - Removal method of heavy metals - Google Patents

Abstract

A heavy metal removal method is provided. The heavy metal removal method includes generating a by-product containing magnesium in a storage tank; collecting and separating the by-products generated in the storage tank; and purifying to increase the purity of the magnesium hydroxide in the collected and separated by-products.

Description

Heavy metal removal method {Removal method of heavy metals}

The present invention relates to a heavy metal removal method.

Magnesium hydroxide can be used to remove anionic heavy metals (antimony, arsenic, chromium, etc.) from water due to the positively charged nature of its surface. However, the magnesium compound has a problem in that its utilization is low due to low economic feasibility to artificially synthesize. On the other hand, in a power plant using seawater as a cooling source, sodium hypochlorite is injected into the water intake in order to suppress the growth or attachment of various adherent marine organisms in the cooling facility. Sodium hypochlorite injected into power plants is produced and used in seawater electrolysis facilities, and produced sodium hypochlorite is stored in sodium hypochlorite storage tanks. Here, salts such as magnesium present in seawater are present together and grow into sludge at the bottom of the sodium hypochlorite storage tank. Such sludge must be periodically removed and disposed of.

Korean Patent Registration No. 10-2215869

The problem to be solved by the present invention is to provide a method for removing heavy metals that is recycled as an environmental cleaning material using magnesium industrial by-products that are discarded without recycling.

In addition, it is to provide a heavy metal removal method capable of removing anionic heavy metals (chromium, arsenic, antimony, etc.)

In addition, in removing anionic heavy metals from water, it is to provide a heavy metal removal method capable of removal through crystallization.

The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the following description.

A method for removing heavy metals according to an aspect of the present invention for achieving the above object includes generating a by-product containing magnesium in a storage tank; collecting and separating the by-products generated in the storage tank; and purifying to increase the purity of the magnesium hydroxide in the collected and separated by-products.

In addition, the storage tank may be a sodium hypochlorite storage tank of a seawater system.

In addition, the by-product may include one or more elements selected from the group consisting of aluminum (Al), sodium (Na), calcium (Ca), sulfur (S), and chlorine (Cl).

In addition, the purifying step may include mixing and dispersing the by-product with distilled water in a 1:1 volume ratio, and chemically dissolving impurities other than the magnesium hydroxide in the by-product using ultrasonic waves.

In addition, the purifying step is to remove elements present in an ionic state in the by-product and the separation liquid using a centrifugal separator, but repeating the separation until the electrical conductivity of the separation liquid is 50 μS / cm or less. and drying the by-product at a set temperature.

In addition, the by-product may be dried for 24 hours at a temperature of 80 ℃.

In addition, the purified by-product may have a magnesium hydroxide content of 70% or more.

In addition, the step of removing the anionic heavy metal in the water by introducing the purified by-product into water may be further included.

In addition, the anionic heavy metal includes at least one heavy metal selected from the group consisting of chromium (Cr), arsenic (As), and antimony (Sb), and the antimony reacts with the by-product to selectively crystallize to form Mg-Sb hydroxide. shape can be achieved.

According to the heavy metal removal method of the present invention as described above, there are one or more of the following effects.

According to the present invention, it is possible to provide a method for removing heavy metals that is recycled as an environmental cleaning material using magnesium industrial by-products that are discarded without recycling.

In addition, it is possible to provide a heavy metal removal method capable of removing anionic heavy metals (chromium, arsenic, antimony, etc.) in water from discarded magnesium industrial by-products at an effective removal rate.

In addition, in removing anionic heavy metals from water, it is possible to provide a heavy metal removal method capable of removal through crystallization.

1 is a flowchart sequentially illustrating a heavy metal removal method according to an embodiment of the present invention.
FIG. 2 is a flowchart sequentially illustrating the heavy metal removal method according to FIG. 1 .
Figure 3 is a graph showing the XRD results of magnesium industrial by-products.
Figure 4 is a photograph showing a sample of magnesium industrial by-products.
5 is a graph showing the antimony removal amount of magnesium by-products for each pH.
Figure 6 is a graph showing the change in the amount of anionic heavy metal removal under the coexistence of interfering ions.
7 is a graph showing the selective bonding characteristics of magnesium industrial by-products and antimony.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Advantages and features of the present invention, and methods for achieving them, will become clear with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms, only the present embodiments make the disclosure of the present invention complete, and the common knowledge in the art to which the present invention belongs It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification.

The spatially relative terms "below", "beneath", "lower", "above", "upper", etc. It can be used to easily describe the correlation between elements or components and other elements or components. Spatially relative terms should be understood as encompassing different orientations of elements in use or operation in addition to the orientations shown in the figures. For example, when flipping elements shown in the figures, elements described as “below” or “beneath” other elements may be placed “above” the other elements. Thus, the exemplary term “below” may include directions of both below and above. Elements may also be oriented in other orientations, and thus spatially relative terms may be interpreted according to orientation.

Although first, second, etc. are used to describe various elements, components and/or sections, it is needless to say that these elements, components and/or sections are not limited by these terms. These terms are only used to distinguish one element, component or section from another element, component or section. Accordingly, it goes without saying that the first element, first element, or first section referred to below may also be a second element, second element, or second section within the spirit of the present invention.

Terminology used herein is for describing the embodiments and is not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase. As used herein, "comprises" and/or "comprising" means that a stated component, step, operation, and/or element is present in the presence of one or more other components, steps, operations, and/or elements. or do not rule out additions.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used in a meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless explicitly specifically defined.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description with reference to the accompanying drawings, the same or corresponding components regardless of reference numerals are given the same reference numerals, Description will be omitted.

1 is a flowchart sequentially illustrating a heavy metal removal method according to an embodiment of the present invention.

Referring to FIG. 1, the heavy metal removal method (S100) according to an embodiment of the present invention includes a step of generating by-products (S110), a step of collecting and separating by-products (S120), a step of purifying the by-products (S130), and removing heavy metals. A removing step (S140) may be included.

Here, the step S130 may include a mixing and dispersing step (S131), a chemical dissolution step (S132), an element removal step (S133), and a drying step (S134).

In the S110, by-products containing magnesium may be generated in the storage tank. Here, the storage tank may correspond to a sodium hypochlorite storage tank of the seawater system.

The by-product may include one or more elements selected from the group consisting of aluminum (Al), sodium (Na), calcium (Ca), sulfur (S), and chlorine (Cl).

The S120 may be obtained by collecting and separating the by-products generated in the storage tank. The S130 may be purified to increase the purity of the magnesium hydroxide in the collected and separated by-product.

The S131 of the S130 may be dispersed by mixing the by-product with distilled water at a volume ratio of 1:1. In the step S132 of the step S130, impurities other than the magnesium hydroxide may be chemically dissolved in the by-product by using ultrasonic waves.

In the step S132 of the step S130, elements present in an ionic state in the by-product and the separated liquid may be removed using a centrifugal separator. At this time, this process may be repeated until the electrical conductivity of the separation solution is 50 μS / cm or less.

In the step S133 of the step S130, elements existing in an ionic state in the by-product and the separated liquid may be removed using a centrifugal separator. This process may be repeated until the electrical conductivity of the separation liquid is 50 μS/cm or less.

The S134 of the S130 may dry the by-product at a set temperature. Here, the by-product may be dried for 24 hours at a temperature of 80 ° C. It is preferable that the by-product purified through these processes has a magnesium hydroxide content of 70% or more.

In S140, the by-products purified through the above-described processes may be put into water to remove anionic heavy metals in the water. Here, the anionic heavy metal may include one or more heavy metals selected from the group consisting of chromium (Cr), arsenic (As), and antimony (Sb).

In addition, the antimony may be selectively crystallized by reacting with the by-product to form an Mg-Sb hydroxide.

Meanwhile, anionic heavy metals (chrome, arsenic, antimony, etc.) are removed using the extracted magnesium by-product as follows, and the procedure is as follows.

1. After mixing dried magnesium by-product powder (0.2 5 g/L) with anionic heavy metal aqueous solution (10 mg/L) and stirring for 24 hours, heavy metal removal was measured using elemental analysis equipment (ICP-MS).

2. The removal amount of anionic heavy metals from magnesium by-products is shown in Table 1 below.

type Removal amount Chromium (Cr) 0.9 Chromium (Cr) 0.9 Arsenic (As) 13.6 Arsenic (As) 13.6 Antimony (Sb) 9.8 Antimony (Sb) 9.8

Among the anionic heavy metals to be removed in Table 1, antimony (Sb) selectively crystallizes with magnesium byproducts and can be removed in the form of Mg-Sb hydroxide (XRD result).

Figure 3 is a graph showing the XRD results of magnesium industrial by-products. Figure 4 is a photograph showing a sample of magnesium industrial by-products. 5 is a graph showing the antimony removal amount of magnesium by-products for each pH.

Figure 6 is a graph showing the change in the amount of anionic heavy metal removal under the coexistence of interfering ions. 7 is a graph showing the selective bonding characteristics of magnesium industrial by-products and antimony.

Referring to FIGS. 3 to 7 together with the above information, the heavy metal removal method (S100) of the present invention can be applied as a new material that can be used as an environmental cleaning material by using magnesium industrial by-products that are discarded without recycling, and negative ions in water Effective removal rate and crystallization removal are possible for heavy metals (chromium, arsenic, antimony, etc.).

Although the embodiments of the present invention have been described with reference to the above and accompanying drawings, those skilled in the art to which the present invention pertains can implement the present invention in other specific forms without changing the technical spirit or essential features. You will understand that there is Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting.

Claims (7)

Generating a by-product containing magnesium in a storage tank;
collecting and separating the by-products generated in the storage tank; and
Including the step of purifying to increase the purity of magnesium hydroxide in the collected and separated by-product,
The purification step is
Mixing and dispersing the by-product with distilled water in a 1:1 volume ratio;
chemically dissolving impurities other than the magnesium hydroxide in the by-product using ultrasonic waves;
Using a centrifugal separator to remove elements present in an ionic state in the by-product and the separation liquid, and repeating the separation until the electrical conductivity of the separation liquid is 50 μS / cm or less;
Further comprising the step of drying the by-product at a set temperature, heavy metal removal method. According to claim 1,
The storage tank is a sodium hypochlorite storage tank of the seawater system, heavy metal removal method. According to claim 2,
Wherein the by-product includes one or more elements selected from the group consisting of aluminum (Al), sodium (Na), calcium (Ca), sulfur (S), and chlorine (Cl). delete delete According to claim 1,
The heavy metal removal method, wherein the by-product is dried for 24 hours at a temperature of 80 ° C. According to claim 1,
The heavy metal removal method further comprising the step of removing the anionic heavy metal in the water by introducing the purified by-product into water.

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