WO2018061915A1

WO2018061915A1 - Shungite refinement method

Info

Publication number: WO2018061915A1
Application number: PCT/JP2017/033846
Authority: WO
Inventors: 藤田　豊久; ジョルジドドビバ; 青木　太一; 健太郎鷹野; ヤナウシニナ
Original assignee: 国立大学法人東京大学; 株式会社アサボウ
Priority date: 2016-09-27
Filing date: 2017-09-20
Publication date: 2018-04-05
Also published as: JP2018051455A

Abstract

[Problem] To provide a shungite refinement method that can efficiently remove metals such as iron, metal compounds, and impurities such as sulfur from shungite ore so as to obtain highly pure shungite. [Solution] A shungite powder is dispersed in water, and a magnetic field is applied to the shungite powder dispersed in the water to remove iron and iron compounds by adsorption. The shungite powder from which iron and iron compounds have been removed by adsorption is further bombarded with microwaves in water or in air to remove sulfur, thereby allowing higher purification to be achieved.

Description

How to refine Sungaito

The present invention relates to a method for purifying sungite.

Shungite is said to have been deposited in the Precambrian period (about 2 billion years ago), is a black carbon ore containing natural fullerenes, and is produced in the Karelia region of Russia. The main features of Sungaito are the following three points.
(1) Carbon and silica in the ore are strongly bonded.
(2) It has electrical conductivity.
(3) Shows strong activity in redox reaction.

From these characteristics, schungite is considered to be an important material for industrial use as a substitute for rubber fillers, water / soil cleaners, and silicon carbide, but is rarely used at present. The reason is that the research is insufficient, the material composition ratio varies depending on the type (carbon content is greatly different), and impurities such as sulfur and iron exist.

Based on the above, in order to use schungite industrially, technology for efficiently purifying schungite is important.

As a method for purifying a carbonaceous material, for example, Patent Document 1 below discloses a desulfurization process. However, with this method, it is difficult to efficiently remove various impurities, particularly metals such as iron, metal compounds, and sulfur from the shungaite ore.

JP 2002-524651 A

An object of the present invention is to provide a method for refining shungait which can efficiently remove impurities such as metals such as iron, metal compounds, sulfur and the like from sungaiite ore and obtain high-pure sungite.

In order to achieve the above object, an embodiment of the present invention is a method for purifying a sungite, a dispersion step of dispersing the sungite powder in water, and a magnetic field acting on the sungite powder dispersed in the water to iron And an iron removal step of adsorbing and removing the iron compound.

In the iron removal step, it is preferable that a magnetic field is applied to a mesh of ferromagnetic stainless steel, and iron and an iron compound are attracted and removed by the mesh.

Moreover, it is preferable to further include a sulfur removal step of removing sulfur by irradiating the sungite powder after the iron removal step with microwaves in water or in air.

Further, the iron removal step may be performed by chelate treatment instead of applying a magnetic field to the schungite powder dispersed in water.

The chelating agent used for the chelation treatment is preferably nitrilotriacetic acid.

Further, the iron removal step may be performed by acid treatment instead of applying a magnetic field to the schungite powder dispersed in water.

The acid used for the acid treatment is preferably reverse aqua regia or a mixture of hydrochloric acid and hydrogen peroxide.

Further, the sulfur removal step may be performed by chelate treatment instead of irradiating the schungite powder with microwaves in water or in air.

Further, the sulfur removal step may be carried out by acid treatment instead of irradiating the sungite powder with water or in air.

According to the present invention, impurities such as metals such as iron, metal compounds, sulfur and the like can be efficiently removed from the ore of sungite, and high-purity sungite can be obtained.

It is a figure which shows the structural example for implementing an iron removal process. It is a figure which shows the structural example for implementing a sulfur removal process. It is a figure which shows the relationship between the irradiation time of a microwave in the sulfur removal process, and the density | concentration of the sulfur in schungite powder.

Hereinafter, modes for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

According to the analysis by the present inventors, the composition ratio of the shungaite ore is about 40% carbon, 43% silica, 3% sulfur, and about 7% iron. Iron includes iron compounds such as iron sulfide.

In the present embodiment, a method for removing iron, iron compounds, and sulfur as impurities from the constituent elements of the schungite ore will be described. Hereinafter, the process of removing iron and iron compounds is referred to as an iron removal process, and the process of removing sulfur is referred to as a sulfur removal process.

<Iron removal process>
FIG. 1 shows a configuration example for performing the iron removal step. In the iron removal step, iron and iron compounds are removed from the sungite. In FIG. 1, in the iron removal step, a shungaite dispersion 12 in which a shungait powder obtained by pulverizing shungaite ore is dispersed in water is placed in a beaker or other appropriate container 10 (dispersion step). A mesh 14 made of a ferromagnetic material such as ferromagnetic stainless steel is disposed on the screen. Next, a magnetic field is applied by magnetic field generating means 16N, 16S such as magnets from both sides (directions facing each other) of the schungite dispersion liquid 12. As a result, the net 14 in the shungait dispersion 12 is magnetized, and iron and iron compounds as impurities present in the shungait dispersion 12 are adsorbed and removed by the net 14. Here, iron sulfide etc. are mentioned as an iron compound.

It should be noted that iron and iron compounds may be adsorbed and removed by using a magnet directly in the schungite dispersion liquid 12 or schungite powder without using the net 14.

<Sulfur removal process>
FIG. 2 shows a configuration example for performing the sulfur removal step. In the sulfur removal step, sulfur is removed from the schungite. In FIG. 2, a schungite powder 22 obtained by pulverizing schungite ore is placed on a saucer 20 disposed in the microwave generator 18, and microwaves are irradiated in the air by the microwave generator 18. Thereby, the sulfur in the schungite powder 22 is heated and vaporized and removed.

In addition, instead of the shungaite powder 22, the sugagate dispersion 12 similar to the example of FIG. 1 may be placed on the saucer 20, and microwaves may be irradiated in water. Moreover, as the shungaite powder 22 or the shungait powder 12 in the shungait dispersion liquid 12, it is preferable to use the sungite powder after the iron removal step.

The microwave used in the sulfur removal process is an electromagnetic wave having a wavelength range of 1 m to 1 mm (frequency is 300 MHz to 300 GHz). The microwave power used is preferably 800 to 1200 W and the irradiation time is preferably 1 to 10 minutes.

<Modification of iron removal step and sulfur removal step>
Modification 1
As modification 1 of an iron removal process and a sulfur removal process, iron, an iron compound, and sulfur can be removed by a chelate process instead of making a magnetic field act on the schungite dispersion liquid 12.

1 A chelating agent is placed in a container 10 shown in FIG. 1 together with a schungite dispersion 12 and stirred at a temperature of 70 to 90 ° C. for 1 to 10 minutes to remove iron, iron compounds and sulfur.

As the chelating agent, nitrilotriacetic acid (NTA), ethylenediaminetetraacetate (EDTA), ethylenediaminetetraacetate (EDTA.2Na) and the like are preferable, and nitrilotriacetic acid is particularly preferable.

Modification 2
As a second modification of the iron removal step and the sulfur removal step, iron, iron compounds, and sulfur can be removed by acid treatment instead of applying a magnetic field to the schungite dispersion 12.

2. An acid is put into the receiving tray 20 shown in FIG. 2 together with the schungite powder 22, and iron, iron compounds and sulfur contained in the schungite powder 22 are dissolved and removed. This operation need not be performed in the microwave generator 18.

The acid is preferably reverse aqua regia or a mixture of hydrochloric acid and hydrogen peroxide. Reverse aqua regia is a mixture of concentrated nitric acid and concentrated hydrochloric acid in a ratio of 3: 1 (concentrated nitric acid 3 to concentrated hydrochloric acid 1).

Hereinafter, embodiments of the present invention will be specifically described. In addition, the following examples are for facilitating understanding of the present invention, and the present invention is not limited to these examples.

<Iron removal process>
In a container 10 shown in FIG. 1, a sungite dispersion (concentration 1.25% by mass) in which sungite powder is dispersed in water is added, and hexametaphosphoric acid as a dispersant is added, and then a magnetic field of maximum 0.98 T is applied. I let you. As described in the example of FIG. 1, iron and iron compounds are sucked and removed by the mesh 14.

As a result of the operation of the iron removal process according to this example, 23% sulfur and 15% iron and an iron compound could be removed.

<Sulfur removal process>
A crucible serving as a tray 20 was placed in the microwave generator 18 shown in FIG. 2, and 3 g of shungaite powder placed in the crucible was irradiated with a microwave of 1000 W at 2.45 GHz for 3 to 9 minutes. When irradiated in air, two operations were performed when 50 ml of pure water was added to the crucible and irradiated in water. The result is shown in FIG.

In FIG. 3, the vertical axis represents the concentration of sulfur (such as SO ₃ ) in the shungite powder, and the horizontal axis represents the microwave irradiation time. As can be seen from FIG. 3, the sulfur concentration decreases with the irradiation time. Therefore, what is necessary is just to determine irradiation time suitably according to the target sulfur concentration. In addition, it is thought that sulfur concentration is falling because sulfur vaporizes. For example, when the microwave was irradiated for 9 minutes, 85% by mass of sulfur could be removed.

<Impuration by chelate treatment>
In a container 10 shown in FIG. 1, a shungaite dispersion (concentration: 0.6% by mass) in which shungait powder is dispersed in water is added, and after the temperature is raised to 80 ° C., nitrilotriacetic acid (NTA) as a chelating agent And stirred for 6 minutes, and then washed with water.

As a result of the chelation treatment, 36% of sulfur and 60% of iron and iron compounds were removed.

<Impurity removal by acid treatment>
Into a crucible serving as the saucer 20 shown in FIG. 2, 3 g of schungite powder was added, 40 ml of a mixture of reverse aqua regia or hydrochloric acid and hydrogen peroxide was added and stirred for 120 minutes, and then washed with water.

When reverse aqua regia was used, the content of iron and iron compound was 10% by mass and sulfur was 5.2% by mass before the acid treatment, and the content of iron and iron compound was 2.0% by mass and sulfur was 0%. Reduced to 9 mass%.

Further, when a mixture of hydrochloric acid and hydrogen peroxide was used, the concentration before the acid treatment was reduced to 1.8% by mass for iron and iron compounds and 1.3% by mass for sulfur.

10 container, 12 sungite dispersion, 14 mesh, 16N, 16S magnetic field generating means, 18 microwave generator, 20 saucer, 22 sungite powder.

Claims

A dispersion step of dispersing the schungite powder in water;
An iron removal step of adsorbing and removing iron and an iron compound by applying a magnetic field to the schungite powder dispersed in water;
A method for purifying Sungaito.
The shungait refining method according to claim 1, wherein in the iron removal step, a magnetic field is applied to a mesh of ferromagnetic stainless steel, and iron and an iron compound are attracted and removed by the mesh.
The method for purifying shungaite according to claim 1 or 2, further comprising a sulfur removal step of irradiating microwaves in water or air to the shungaite powder after the iron removal step to remove sulfur.
The method for purifying shungait according to any one of claims 1 to 3, wherein the iron removal step is performed by chelate treatment instead of applying a magnetic field to the sungite powder dispersed in water.
The method for purifying schungite according to claim 4, wherein the chelating agent used in the chelation treatment is nitrilotriacetic acid.
The method for purifying shungait according to any one of claims 1 to 3, wherein the iron removal step is performed by an acid treatment instead of applying a magnetic field to the shungait powder dispersed in water.
The method for purifying schungite according to claim 6, wherein the acid used for the acid treatment is reverse aqua regia or a mixture of hydrochloric acid and hydrogen peroxide.
The method for purifying shungait according to claim 3, wherein the sulfur removal step is performed by chelate treatment instead of irradiating the sungite powder with microwaves in water or in air.
The method for purifying schungite according to claim 8, wherein the chelating agent used for the chelation treatment is nitrilotriacetic acid.
4. The method for purifying sungaiite according to claim 3, wherein the sulfur removal step is performed by acid treatment instead of irradiating the sungite powder with microwaves in water or in air.
The method for purifying schungite according to claim 10, wherein the acid used in the acid treatment is reverse aqua regia or a mixture of hydrochloric acid and hydrogen peroxide.