KR101847419B1 - Method for preparing high purity silica using reverse flotation - Google Patents

Abstract

The present invention relates to a method for purifying silica in silica and an ore containing impurity minerals, the method comprising the steps of: an ornithine analysis step of analyzing a mineral component of the ore; A zeta potential measurement step of measuring a post-zeta potential; Selecting a first catcher having a charge opposite to the zeta potential of the first reference sample among the standard samples and floating the first reference sample; And a first inverted flaky step of floating the flocculant and the first catcher in water to remove the first impurity mineral floating in the water.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for purifying high purity silica using a flotation line,

The present invention relates to a method for purifying high purity silica, and more particularly, to a purification method for high purity silica using a reverse flame.

In order to produce a high-quality silica raw material having a silica (SiO2) content of 99% or more, a physical refining method such as crushing or grinding silica to select a specific gravity and magnetic force is generally used.

On the other hand, in the case of high purity silica, it is used as a filler for paints, low iron glass, silicon metal, and quartz crucible, and its utilization has been increasing. However, in Korea, high grade silica raw materials are imported, processed, used or imported In fact.

Therefore, in order to secure long-term high-purity silicate raw materials used as raw materials for high-value-added products, it is necessary to develop advanced purification technology that is better than today. One of the advanced refining technologies is float sorting process using physicochemical surface characteristics of minerals .

As a conventional method for producing high purity silica, according to Korean Patent Application No. 10-1988-0002401, there is a method of treating low-grade silica with sulfuric acid to obtain high purity silica of 99.7% or more. According to Korean Patent Application No. 10-1990-0017856 A method of treating low-grade silica with aqua regia (nitric acid + hydrochloric acid) to obtain 99.9% or more of high purity silica is disclosed.

However, in order to produce silica, acid treatment using strong acid such as sulfuric acid and nitric acid + hydrochloric acid, such as aqua regia, causes great problems such as human health hazards and corrosiveness to peripheral devices, There is a problem that economical efficiency is low.

As another method of producing high purity silica, Korean Patent Application No. 1988-0002401 discloses a method of treating a low-grade silica with sulfuric acid to obtain high purity silica containing 99.7% or more of SiO2, and Japanese Patent Application No. 1990-0017856 A process for obtaining high purity silica containing 99.9% or more SiO2 by treating low-grade silica with a royal flue.

On the other hand, Japanese Patent Application No. 10-2002-0005190 discloses a method of obtaining high purity silica containing 99.9% of SiO 2 by pulverizing / classifying natural silica to an appropriate particle size, and by magnetic separation and organic acid treatment. In addition, Korean Patent No. 10-2011-0049197 discloses a high purity silica purification method using low-grade silica.

As described above, various methods and additives are used to purify the silica ore. However, since the method of purifying silica using strong acid such as aqua regia in Korea is not suitable in terms of environmental problems and economics, Are mostly physical sorting such as specific gravity sorting and magnetic force sorting.

However, there are limitations in the removal of non - magnetic minerals by specific gravity and magnetic force lines. Therefore, in order to produce high purity silica from various crystalline phases, it is necessary to study the flotation screening.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a purification method of high purity silica by floating sorting which can sort and recover sophisticated silica concentrates from various kinds of silicates, .

Another object of the present invention is to provide a purification method of high purity silica which can reduce reagent consumption and recovery rate by using a reverse flotation process.

According to an aspect of the present invention, there is provided a method for purifying high purity silica,

A process for purifying silica from silica and an ore containing impurity minerals other than said silica,

An ornithine analysis step including an analysis of a mineral component of the ore;

A crushing and crushing step of crushing or crushing said raw material

A physical purification step of purifying the impurities by a physical method so that the content of the impurities is 1 to 5% by weight;

A zeta potential measuring step of measuring a zeta potential after inserting a standard sample of each impurity mineral analyzed in the step of analyzing the nacreous into water;

Selecting a first catcher having a charge opposite to that of the first reference sample in the standard sample and floating the first reference sample; And

And a first flogging step of floating the flocculant and the first catcher in water to remove the first impurity mineral floating in the water.

At this time, the amount of the first catcher added is preferably 0.01 to 0.2 per 100 parts by weight of the mineral.

Further, after the first flip-flops,

Selecting a second catcher having a charge opposite to the zeta potential of the second reference sample among the standard samples and floating the second reference sample; And

And a second inverted line step of removing the second impurity mineral suspended in the water by adding the natural light and the selected second catcher into water.

Further, the method may further include at least one of a gravity selection step and a magnetic force selection step between the crushing and crushing step and the zeta potential measurement step.

The first flotation step may further include a foaming agent.

In addition, a pH adjuster may be further included in the first flotation step.

In addition, the pH adjusting agent is preferably composed of oxalic acid.

Further, it is preferable to adjust the pH to 1 to 3 when oxalic acid is used.

The purification method of high purity silica according to one aspect of the present invention is capable of separating non-magnetic minerals by applying a reverse flotation process in a silica raw material mixed with various kinds of minerals and can produce a high purity silica having a high recovery rate of the concentrate have.

The use of oxalic acid, which is an organic acid, as a pH controlling agent has the effect of producing a high purity silica in a safer and more economical manner, and a high quality silica can be produced when a subsequent step such as acid leaching is added.

In addition, it is effective to recover high purity silica of 99% or more of SiO2 even in non-magnetic impurities which are difficult to separate by magnetic force lines, and in 90 to 98% of low grade silica of SiO2 content and SiO2 content.

Before describing the present invention in detail, it is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention, which is defined solely by the appended claims. shall. All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise stated.

Throughout the description and claims, unless the context requires otherwise, the word "comprise" is intended to include the stated article, step or group of articles, and steps; It is not meant to exclude an object, step or group of objects or a group of steps.

On the contrary, the various embodiments of the present invention can be combined with any other embodiments as long as there is no clear counterpoint. In particular, any feature that is indicated to be advantageous or advantageous may be combined with any other feature or feature that is indicated to be advantageous or advantageous.

The purification method of high purity silica according to an embodiment of the present invention includes the step of analyzing the raw light, the step of measuring the zeta potential, the step of selecting the catcher, and the step of inverted flotation.

The step of analyzing the raw light is a step of analyzing the kind and content of the constituent minerals contained in the silica raw ore.

That is, in order to produce a high quality silica sand using the floating sorting process as described later, it is necessary to separate the non-silica quartz minerals mixed with the natural quartz ore, It is a step to confirm kinds and contents of minerals.

In general, natural quartz is composed of various kinds of quartz, including muscovite (KAl2 (AlSi3O10) (F, OH) 2), hematite (Fe2O3), feldspar (potassium feldspar: KAlSi3O8, sodium feldspar: NaAlSi3O8, soda feldspar: CaAl2Si2O8) Minerals are mixed.

In the step of analyzing the raw light, various methods can be used to grasp the chemical components in the ore, kinds of minerals, contents of each kind, and the like. For example, the chemical composition of ore was analyzed through ICP, XRF, and XRD and polarization microscope were used to identify the constituent minerals contained in the ore, and then the theoretical composition, chemical composition analysis, Based on this, it is possible to confirm the kinds of impurity minerals in the ore and their contents according to the types.

The zeta potential measurement step is a step of measuring the zeta potential of each standard sample after putting the standard sample of the analyzed impurity minerals into water.

Since the surface potential of the mineral can not be directly measured, the zeta potential with the same polarity but with the same absolute value is measured.

In this case, the pH at which the zeta potential of the mineral is zero is referred to as the isepoint point (iep) or the point of zero charge (pzc), and the mineral surface is positive charge at pH lower than pzc, (Negative charge).

Therefore, it can be confirmed by measuring the zeta potential of these minerals in the aqueous solution by using pure mineral (standard sample) of the minerals present in the ore. This is because it is necessary to select a suitable catcher to be used in certain minerals during refining among the widely available floating catchers.

The selecting step of the catcher is a step of selecting a catcher having a floating degree of 80 to 100% in a pH range selected for the standard sample from a catcher having an electric charge opposite to that of the zeta potential of each standard sample.

Catchers do not give mechanical action or mechanical entanglement between mineral particles and bubbles, but are reagents that make the surface of minerals hydrophobic. All reagents used as catchers belong to organic compounds.

In the present invention, suspended doran is defined as the extent to which the mineral bound with the catching agent in the aqueous solution is suspended and recovered together with the bubbles.

In other words, the floating degree of various catchers according to the pH of the aqueous solution of the single mineral standard samples such as quartz, muscovite, hematite and feldspar is confirmed.

The inverted flotation step is a step in which the raw ore and the selected catching agent are put into water and the impurity minerals floating at the pH are removed.

The catcher placed in the water is adsorbed on the constituent minerals of the organs to hydrophobicize the constituent minerals surface, so that the constituent minerals float with the bubbles. In this case, since the catcher exhibits a higher degree of suspension for a specific constituent mineral, a suitable catcher is selected depending on the type and number of the constituent minerals, so that this step can be repeatedly performed.

For example, a suitable catcher for removal of impure minerals such as muscovite and opacite minerals is the amine cationic catcher.

In this step, it is preferable that a foaming agent and a pH adjuster are further included.

The foam agent adsorbs on the liquid-gas interface to lower the surface tension of water to facilitate formation of fine bubbles and stable froth formation. It is not limited to the present invention, but MIBC (methyl isobutyl carbinol), n-Pentanol, Isoamyl At least one foaming agent selected from the group consisting of Alc, Hexanol, Heptanol, Caprylic Alc, and 4-Hepanol may be used.

In the general floating sorting process, sulfuric acid is frequently used as a pH regulator. In the case of sulfuric acid, since it is a health hazard factor for the human body and a high corrosivity to peripheral devices, the present embodiment is easier to handle than sulfuric acid, Which is more economical than sulfuric acid, to improve the quality of silica sand.

In general, the parameters influencing the flotation screening process include the type and amount of catcher, the type and amount of foaming agent, the pH of the optical fluid, the concentration of the optical fluid, the particle size of the sample, the temperature of the optical fluid, the stirring speed, time, floating time (float recovery time), and so on.

The addition amount of the catching agent is preferably 0.01 to 0.2 based on 100 parts by weight of the mineral. When the amount is over 0.2, the adsorbent that is not adsorbed adsorbs on the silica to lower the recovery rate, and excessive use of the reagent increases the unit cost of the final product. If the amount is less than 0.01, the carrier should be floated There is a problem that the quality of the product may be deteriorated because it is not allowed to float the minerals to be suspended due to less amount of the minerals.

The addition amount of the foaming agent is preferably 0.005 to 0.03 per 100 parts by weight of the mineral. If it is more than 0.03, there is a problem that a large amount of bubbles are generated to float to silica to lower the recovery rate, and also there is a problem of cost increase. When the amount is less than 0.005, there is a problem that the amount of bubbles is small and the mineral to be floated can not be floated Because.

It is preferable that the pH of the optical fluid is 2.0 to 3.5, the concentration of the optical fluid is 15 to 25.0 wt%, the temperature of the optical fluid is 10 to 50 DEG C, and the air injection amount is 2 to 5 L / min. When the pH of the solution is out of the range of 2.0 to 3.5, the selective reagent adsorption ability of only the mineral to be suspended is lowered, and the impurity to be removed can not be removed.

If the concentration of the optical solution is more than 25wt%, the concentration of the slurry may become high and problems such as clogging may occur. If the concentration of the optical solution is set to 15wt% or less, The consumption may increase and the economical efficiency may be lowered.

The reason why the temperature of the optical liquid is maintained at 10 to 50 ° C is that if the temperature is lowered to 10 ° C or less, the adsorption reactivity may be lowered. If the temperature is kept at 50 ° C or more,

The amount of air injected to help generate air bubbles is maintained at 2 to 5 L / min. When the amount of air injected is small, air bubbles may be broken if air is injected excessively due to small amount of air bubbles. In addition, the selection efficiency due to excessive bubbles may be decreased, the size of the bubbles may be turned on, the recovery rate may be lowered due to flocculation of part of the silica, and the selectivity may be deteriorated due to the change of the vortex and bubble layer position due to the air pressure.

Meanwhile, at least one physical separation step may be further included between the step of measuring the zeta potential and the step of measuring the zeta potential, the step of crushing and crushing, the step of selecting non-gravity, and the step of selecting the magnetic force. This is for the purpose of floating the impurity minerals on the silica having an impurity content of less than 1 to 5 wt% in the floating sorting process so as to reduce reagent consumption and increase the recovery rate.

The crushing and crushing steps are a primary step to make the silica of the particle size suitable for the purpose. At this time, it is preferable that the particle size of the raw light is crushed or pulverized to 0.045 to 0.3 mm to 0.045 to 0.6 mm.

The step of selecting the specific gravity is a step of selecting grains of 0.1 to 0.6 mm through a screen classifier, and the step of magnetically separating grains is a step of removing iron ore introduced at the time of shale mining or grinding.

Examples and Experimental Examples

In one embodiment of the present invention, quartz ore generated from the quartzite layer of Gapyeong, Gyeonggi-do, Korea was purified as described above. The types and contents of chemical components, types and contents of minerals are summarized in Table 1 and Table 2 through analysis of chemical composition and crystal phase of silica ore. The chemical composition of the ore is analyzed by ICP, XRF, etc., and XRD and polarized microscope are used to identify the types of constituent minerals contained in the ore, and then the theoretical composition, The contents of impurity minerals in the ore were examined and the contents of them were determined.

division SiO2 Al2O3 Fe2O3 CaO MgO Na2O K2O TiO2 SUM Experimental Example 1 97.43 1.48 0.41 0.01 0.03 0.15 0.48 0.01 2.57

stone Analysis item quartz muscovite Opaque mineral
(Outside hematite) Experimental Example 2 content(%) 96.4 3.5 0.1

The slurry was removed by crushing and crushing / classification processes, and the slurry was adsorbed on the surface of silica sand by removing the slime from the crushed silica sand. After the particles were selected, magnetic iron ore was removed by magnetic force selection.

After that, the particles of 0.1 to 0.3 mm were screened again with a screen classifier, and the types and contents of the chemical components after wave / pulverization and specific gravity selection and magnetic force selection were summarized as shown in Table 3.

division SiO2 Al2O3 Fe2O3 CaO MgO Na2O K2O TiO2 SUM Experimental Example 3 98.93 0.67 0.11 0.01 0.03 0.01 0.2 0.04 1.07

According to this, it can be confirmed that the chemical components after wave / pulverization, specific gravity selection, and magnetic separation are higher in SiO2 content than the previous stage.

The zeta potential of each standard sample such as muscovite, hematite and the like, which is an impurity mineral, was measured and shown in Fig.

According to the results, the zeta potential changes measured by the pH change of the aqueous solutions of the impurity minerals in the ore collected from Gapyeong can be seen.

Next, a catcher having a floating degree of 80 to 100% relative to the standard sample was selected from among the catchers having charge opposite to the zeta potential of each of the standard samples. For example, since the zeta potential of muscovite is negatively charged, mixed amines with a degree of suspension of 80% are selected as the catcher of muscovite in the positive charge type (see Table 4). Table 4 summarizes the suspended levels of each mineral according to catcher and pH. In the present embodiment, the measurement of the floating degree of the standard sample and the catching agent was performed using a glass tube named Hallimond Tube. Stirring magnet is located at the bottom of the tube to help adsorption of minerals and reagents, and it is rotated to the external magnetic stirrer. Air is injected into the bottom of the tube to facilitate bubble generation. Above the upper part, suspended particles were recovered separately by giving a slope of about 30 있도록 so that the foam layer made of the catcher and adsorbed minerals and bubbles could be recovered, and the floating degree with the specific mineral was measured. By using this, it was possible to confirm the floating degree of various catchers according to the pH of the aqueous solution by using standard single mineral samples such as quartz, muscovite, hematite, and feldspar.

Collector information Maximum flotation yield%
(pHrange) Remark
(Goodfloatingminerals) Chemical composition Type Muscovite
muscovite Hematite
Hematite Feldspar
feldspar Mixed amine Cationic 80%
(6-8) 30%
(3-8) 85%
(6-8) solid, white
(Muscovite, feldspar, quartz) Mixed polyglycol Anionic 50%
(3 to 4) 60%
(6) 40%
(Less than 6) come reddish brown
(Hematite) Mineral oil + Sulphonic acid, petroleum, sodium salts + Heavy paraffinic Anionic 30%
(3-8) 80%
(3) 50%
(3) liquid, amber-brown
(Hematite) Coco amine acetate Cationic 80%
(4-5) 10%
(3-8) 60%
(7) paste, yellow
(Muscovite, feldspar) Tallow amine acetate Cationic 85%
(3 to 4) 10%
(3-8) 70%
(3 to 4) solid, yellow
(Muscovite, feldspar)

Next, the raw ore provided and the catcher, foam and pH adjuster thus selected were put into water to remove airborne impurities by generating air bubbles.

The floating separator used in this embodiment is a floating separator of Denver Sub-A Type, which adsorbs minerals and trappers by a high-speed rotating impeller, and a certain amount of air is injected into the impeller to adsorb the mineral and adsorbed reagents to the surface of the slurry It is coming up.

In order to impart the adsorption time of the mineral and the trapped agent and to give the foaming agent a smooth bubble generation function, stirring of the sample and the process water and adjustment of the pH for 5 minutes, the condition for giving the condition for catching agent for 5 minutes, I gave it 5 minutes.

 Other conditions were pH 3.0 ~ 3.5, optical density 16.7 ~ 20.0wt%, optical temperature 20 ~ 30 ℃ and air injection rate 3 ~ 5ℓ / min. In order to improve the quality, the addition amount of amine-based catcher was increased to 400 g / t, and the number of barges was increased to 2 times and 3 times in other conditions, and the results were shown in Examples 7 and 8.

division SiO2 Al2O3 Fe2O3 CaO MgO Na2O K2O TiO2 SUM Experimental Example 4 99.47 0.32 0.05 0.02 - 0.02 0.11 0.02 0.53 Experimental Example 5 99.51 0.29 0.05 0.02 - 0.02 0.10 0.02 0.49 Experimental Example 6 99.57 0.26 0.05 0.02 - 0.02 0.09 0.01 0.43 Experimental Example 7 99.64 0.22 0.04 0.01 - 0.01 0.07 0.01 0.36 Experimental Example 8 99.65 0.22 0.04 0.01 - 0.01 0.07 0.01 0.35 Experimental Example 9 99.72 0.17 0.03 0.00 - 0.02 0.06 0.01 0.28

In Experimental Examples 4 to 6 in Table 5, the amount of the catching agent added was increased to 50 g / t (1 ton of silica), 200 g / t and 400 g / t, The results are shown in Fig. Experimental example 9 is a result of adding oxalic acid instead of sulfuric acid as the pH adjusting agent.

It can be seen from the analysis results of Experimental Examples 4 to 6 that more impurities are removed than in Experimental Example 1, and that in Experimental Examples 7 to 8, SiO 2 quality is improved as compared with Experimental Example 6. [ In Experimental Example 9, it can be confirmed that SiO 2 was improved to 99.7% or more.

While the present invention has been described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. And such modifications are within the scope of the present invention.

The scope of the present invention is defined by the following claims, and is not limited to the description of the specification, and all variations and modifications falling within the scope of the claims are included in the scope of the present invention.

Claims (8)

A process for purifying silica from silica and an ore containing impurity minerals other than said silica,
An ornithine analysis step including an analysis of a mineral component of the ore;
A crushing and crushing step of crushing or crushing said raw material
A physical purification step of purifying the impurities by a physical method so that the content of the impurities is 1 to 5% by weight;
A zeta potential measuring step of measuring a zeta potential after inserting a standard sample of each impurity mineral analyzed in the step of analyzing the nacreous into water;
Selecting a first catcher having a charge opposite to that of the first reference sample in the standard sample and floating the first reference sample; And
And a first flotation step of removing the first impurity mineral floating by adding the raw ore and the first catching agent in water containing oxalic acid as a pH adjusting agent to suspend the flotation. The method according to claim 1,
Wherein the amount of the first capturing agent added is in the range of 0.01 to 0.2 per 100 parts by weight of the mineral. The method according to claim 1,
After the first flip-flops,
Selecting a second catcher having a charge opposite to the zeta potential of the second reference sample among the standard samples and floating the second reference sample; And
And a second reverse flotation step of removing the second impurity mineral suspended in the water by adding the raw ore and the selected second catching agent into water to refine the high purity silica. The method according to claim 1,
Further comprising at least one of a gravity selection step and a magnetic force selection step between the crushing and crushing step and the zeta potential measurement step. The method according to claim 1,
Wherein the first flotation step further comprises a foaming agent. delete delete The method according to claim 1,
Wherein the pH is adjusted to 1 to 3 when using the oxalic acid.