JPH10265218A - Increase of purity of fine limestone powder by flotation and removal of carbonaceous impurity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently remove carbonaceous particles of impurities and to obtain high purity powdery limestone stock having high whiteness by subjecting raw limestone ore pulverized to a specified particle size to flotation with a alcoholic frother and alkaline pulp and separating floated ore as impurities. SOLUTION: Raw limestone ore is pulverized to fine powder of <=100 mesh and sodium silicate as a dispersant, sodium carbonate, sodium hydrogencarbonate, >=3C alcohol as an active agent, kerosene as a capturing agent, an alcoholic frother and water are added to the fine powder to prepare an aq. dispersion. Air is introduced into the dispersion by stirring, flotation is carried out with alkaline pulp kept at >=60 deg.C and floated ore is separated as impurities. Precipitated ore is rapidly heated at 600-900 deg.C and the residual carbon-contg. org. matter is thermally decomposed, volatilized and removed. Impurities are removed from the gray raw ore and the whiteness and purity of the ore are increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for purifying limestone fine powder by floating removal of carbon-based impurities, and more particularly, to building materials, cement raw materials, iron-making raw materials, crushed stones, pollution control materials, and other industrial materials. The present invention relates to a method for purifying general-purpose limestone used as a raw material for use.

[0002]

2. Description of the Related Art The general-purpose limestone described above does not have a problem with whiteness, and crushed and pulverized limestone is used as it is. Limestone contains various impurities, and therefore presents a color such as gray or light black, but the color or pattern is directly used as a lump or solid except for the case where the color or pattern is prized for use as a wall for arts and crafts or buildings.
It is currently used as granules and powder. On the other hand, limestone powder used for limestone, filler, food, and medicine for papermaking application is required to have high whiteness and high purity.
For this reason, a method of selecting and grinding raw ore having high whiteness and high purity has conventionally been adopted. That is, this is a method of selectively mining ore deposits of calcite and aragonite having high whiteness and purity and using them as raw materials.

[0003]

However, such high-quality raw ores in the natural world are limited in quantity, and reserves are recently reduced, and impurities are removed from raw ores having a gray or black ink color to some extent. Except for this, it is necessary to develop a technique for increasing the whiteness and purity.
The reason that the general-purpose limestone exhibits a gray or light-black color is that it mainly contains carbonaceous particles as impurities, and contains carbon having a particle diameter of about 1 μm to 10 μm, which is a whiteness. , Lowering the purity.
There are also inorganic and organic carbonaceous particles

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the conventional general-purpose limestone, and it is an object of the present invention to efficiently remove carbonaceous particles as impurities and obtain a high-purity limestone raw material having high whiteness. It is an object to provide a method by which a powder can be obtained.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The first invention of the present application is to grind limestone raw material ore into fine particles of 100 mesh or less, flotate with alkaline pulp using an alcohol-based foaming agent, and separate impurities as flotation. This is a method for purifying limestone fine powder by removing carbon-based impurities. In the second invention, limestone raw material ore is pulverized into fine particles of 100 Messi or less, flotated with alkaline pulp using an alcohol-based foaming agent, impurities are separated as flotation, and the precipitated mineral is dried and dried. A method for highly purifying limestone fine powder by removing carbon-based impurities, characterized by rapidly heating in air at a temperature of 600 ° C. or more and 900 ° C. or less and thermally decomposing and volatilizing and removing residual carbon-containing organic matter. .

In a third aspect of the present invention, a limestone raw material ore is pulverized into fine particles of 100 mesh or less, flotated with alkaline pulp using an alcohol-based foaming agent, impurities are separated as flotation, and precipitated minerals are separated. This is a method for purifying limestone fine powder by removing carbon-based impurities, which is characterized by rapidly heating in air at a temperature of 600 ° C. or more and 900 ° C. or less to thermally decompose and volatilize and remove carbon-containing organic matter. Embodiments of the present invention are as follows. The above method is characterized in that sodium carbonate or sodium bicarbonate is further used as an activator. The above method is characterized in that the activator further contains an alcohol having 3 or more carbon atoms. The above method is further characterized in that kerosene is used as a collecting agent. The above method is characterized in that sodium silicate is used as the ore dispersant. The above method is further characterized in that sodium carbonate or sodium bicarbonate and an alcohol having 3 or more carbon atoms are used as an activator, and sodium silicate is used as a dispersant for the ore. The alkaline pulp is maintained at a temperature of about 60 ° C. or higher.

In the present invention, the limestone raw material ore is 100
When pulverized beyond the mesh, impurities or ores containing the impurities cannot be efficiently suspended. Even if the above mineral is heated at a temperature lower than 600 ° C., carbon-based impurities cannot be removed without thermal decomposition. If the mineral is heated at a temperature exceeding 900 ° C., the limestone raw material ore may be altered. The pulp of the alkaline pulp is a term of the beneficiation method and means a suspension in which ore fine powder is dispersed in water. Examples of the alcohol-based foaming agent include Dowfros (a mixture of homologues of jetylene glycol glycol), MIBC (methyl isobutyl carbinol), and pine oil.

[0008]

According to the present invention, there is an effect that carbonaceous particles as impurities can be efficiently removed and a high-purity limestone raw material powder having high whiteness can be obtained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS For flotation, for example, a denper type FW flotation machine is used. The limestone (calcite) sample is from Shiriya. As shown in FIG. 1, the capacity of the stainless steel mortar 10, the coffee mill 12, and the alumina balls is about 1/4 and 20 g / l.
Was milled in a dry system for 4 hours using a ball mill 14 having a ratio of After that, 100mesh, 150mes
h, 200 mesh, 270 mesh, 400 mesh, wet sieving 16 and drying 18. This sample is
Organic carbon ratio of 0.015%, total carbon content of 11.9
2%. The pulp concentration in flotation is about 0.6%. The cell of the flotation machine was about 350 ml, and the sample was placed in the cell, pure water was added, and the pH was adjusted while stirring.

[0010] Thereafter, as shown in FIG.
After adding the active agent 32, the collector 34, and the foaming agent 36 in this order and conditioning them, the rotation speed of the invera is 1500rpm (peripheral speed 50cm / s
), The mixture was flotated 40 by introducing air at about 2 l / min. For 1 kg of ore, 0.5 kg of sodium silicate as a dispersant, 40 g of IAA (isoamyl alcohol, 3-methyl-1-butanol) as an activator, 1 kg of kerosene as a collector, and MIBC (methyl isobutyl carbinol) as a foaming agent Flotation was performed using 20 g. Dauflors, a homologous mixture of diethylene glycol glycol carbinol, can also be used as a foaming agent. As a dispersant, sodium bicarbonate, sodium carbonate, or the like can also be used. FIG. 3 shows a flotation result when the temperature is changed. In FIG. 3, the horizontal axis represents the pulp temperature (° C.), the left vertical axis represents the distribution of impurities and calcite in the floating material (%), and the right vertical axis represents the impurity quality (%) in the sediment.
The left and right arrows attached to the graph indicate the vertical axes in each direction. Using warm water above 60 ° C., the impurities in the limestone were suspended by 40%, and the impurities in the sediment, which became calcite concentrate, were reduced from 0.17% to 0.10%. The actual yield of calcite as a sediment was 90% or more, and black impurities were successfully removed from calcite.

The above sediment is further placed in an electric furnace (muffle furnace) and heated in an air atmosphere for up to 5 minutes to volatilize and remove the carbon-containing organic matter.

[Brief description of the drawings]

FIG. 1 is a process diagram of a pulverizing step in a method for purifying limestone fine powder by floating removal of carbon-based impurities according to an embodiment of the present invention.

FIG. 2 is a process diagram of a flotation step in a method for purifying limestone fine powder by floating removal of carbon-based impurities according to an embodiment of the present invention.

FIG. 3 is a graph illustrating the results of flotation by a method for purifying limestone fine powder by floating removal of carbon-based impurities according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 mortar made of stainless steel 12 coffee mill 14 ball mill 16 sieving 18 drying 30 dispersant 32 active agent 34 collecting agent 36 foaming agent 40 flotation

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toyohisa Fujita 13-4 Hiromotakada, Akita City, Akita Prefecture

Claims (10)

[Claims] 1. A carbon-based impurity characterized in that limestone raw material ore is pulverized into fine particles of 100 mesh or less, flotated with alkaline pulp using an alcohol-based foaming agent, and impurities are separated as flotation. Method of purifying limestone fine powder by floating removal of water. 2. The method for purifying limestone fine powder by floating removal of carbon-based impurities according to claim 1, wherein sodium carbonate or sodium bicarbonate is further used as an active agent. 3. The method for purifying limestone fine powder by floating removal of carbon-based impurities according to claim 2, wherein the active agent further contains an alcohol having 3 or more carbon atoms. 4. The method for purifying limestone fine powder by floating removal of carbon-based impurities according to claim 1, wherein kerosene is further used as a collector in the above method. 5. The method for purifying limestone fine powder by floating removal of carbon-based impurities according to claim 1, wherein in the method, sodium silicate is used as a dispersant for the ore. 6. The method according to claim 1, further comprising using sodium carbonate or sodium bicarbonate as the active agent and an alcohol having 3 or more carbon atoms, and using sodium silicate as a dispersant for the ore. A method for purifying limestone fine powder by floating removal of the carbon-based impurities described in the above. 7. The alkaline pulp is heated to a temperature of about 60 ° C.
The method for purifying limestone fine powder by floating removal of carbon-based impurities according to claim 1, wherein the limestone is held as described above. 8. The alkaline pulp is heated to a temperature of about 60 ° C.
The method for purifying limestone fine powder by floating removal of carbon-based impurities according to claim 1, wherein the limestone is held as described above. 9. The method for purifying limestone fine powder by floating removal of carbon-based impurities according to claim 3, wherein the alcohol having 3 or more carbon atoms is isoamyl alcohol. 10. A limestone raw material ore is pulverized into fine particles of 100 mesh or less, flotated with alkaline pulp using an alcohol-based foaming agent, impurities are separated as flotation, and the precipitated mineral is dried and dried. A method for highly purifying limestone fine powder by floating removal of carbon-based impurities, which comprises rapidly heating in air at a temperature of 600 ° C. to 900 ° C. to thermally decompose and volatilize and remove the remaining carbon-containing organic matter.