阅读说明：本技术 一种高纯度致密镁橄榄石的制备方法 (Preparation method of high-purity compact forsterite ) 是由 王衍森 钱景辉 司继庆 于 2019-11-28 设计创作，主要内容包括：本发明涉及一种高纯度致密镁橄榄石及其制备方法,属于耐火材料技术领域。本发明所述的高纯度致密镁橄榄石,使用高纯度海水镁砂和高纯度石英,使用有机结合剂,制备方法如下：高纯度海水镁砂50-65%,高纯度石英砂35-50%,外加有机结合剂0.1-3%,装入球磨机中湿法研磨至中位粒径D50≤10微米,过325目振动筛后滤泥、真空炼泥及挤出成型为块状坯体,烘干、1600℃-1700℃保温8-16小时烧成。本发明所述的高纯度致密镁橄榄石,杂质含量极低、SiO<Sub>2</Sub>+MgO≥99%,其他杂质≤1%,镁橄榄石纯度高,气孔率≤3%,体积密度≥2.7g/cm<Sup>3</Sup>；本发明同时提供了一种简单易行、节能环保的制备方法。(The invention relates to high-purity compact forsterite and a preparation method thereof, belonging to the technical field of refractory materials. The high-purity compact forsterite is prepared from high-purity seawater magnesite, high-purity quartz and an organic bonding agent, and has the following preparation method: 50-65% of high-purity seawater magnesia, 35-50% of high-purity quartz sand and 0.1-3% of additional organic bonding agent, the materials are put into a ball mill for wet grinding until the median particle diameter D50 is less than or equal to 10 microns, the materials are filtered, vacuum-mixed and extruded to form a block blank after being screened by a 325-mesh vibrating screen, and the block blank is dried and is sintered at 1600-1700 ℃ for 8-16 hours. The high-purity compact forsterite has extremely low impurity content and SiO 2 More than or equal to 99 percent of MgO, less than or equal to 1 percent of other impurities, high purity of forsterite, less than or equal to 3 percent of porosity and more than or equal to 2.7g/cm of volume density 3 (ii) a The invention also provides a simple, feasible, energy-saving and environment-friendly preparation method.)

1. The preparation method of the high-purity compact forsterite is characterized by comprising the following components in percentage by mass: 50-65% of high-purity seawater magnesia, 35-50% of high-purity quartz sand and 0.1-3% of organic bonding agent.

2. A preparation method of high-purity compact forsterite is characterized by comprising the following steps:

(1) weighing and mixing high-purity seawater magnesia, high-purity quartz sand and an organic binding agent according to a set proportion;

(2) putting the ingredients into a ball mill, adding water accounting for 60 percent of the total weight of the raw materials, and carrying out wet grinding until the median particle size D50 is less than or equal to 10 micrometers;

(3) filtering and removing iron from the slurry by a 325-mesh vibrating screen and an iron remover;

(4) after mud filtering and vacuum mud refining, the mixture is extruded and molded into a block-shaped blank body;

(5) drying in a drying vehicle at 120 deg.C for 12 hr;

(6) calcining at 1600-1700 deg.c for 8-16 hr.

3. The method for preparing high-purity compact forsterite according to claim 1, wherein: the chemical composition requirements of the high-purity seawater magnesite are as follows: MgO is more than or equal to 99 percent.

4. The method for preparing high-purity compact forsterite according to claim 1, wherein: the high-purity quartz sand is natural quartz or fused quartz or a mixture of the natural quartz and the fused quartz, and the chemical components of the quartz sand are required as follows: SiO 2₂≥99%。

5. The method for preparing high-purity compact forsterite according to claim 1, wherein: the organic binder is polyvinyl alcohol or carboxymethyl cellulose.

6. The method for preparing high-purity compact forsterite according to claim 1, wherein: the porosity of the prepared high-purity compact forsterite is less than or equal to 3 percent, and the volume density is more than or equal to 2.7g/cm³。

7. The method for preparing high-purity compact forsterite according to claim 1, wherein: the prepared high-purity compact forsterite can be used for manufacturing forsterite refractory materials for cement kilns.

Technical Field

The invention belongs to the technical field of refractory materials, and particularly relates to high-purity compact forsterite and a preparation method thereof.

Background

Forsterite is island-structure silicate with a theoretical chemical formula of 2 MgO. SiO₂Or Mg₂SiO₄The refractory magnesia material has high melting point, low heat conductivity, high stability, excellent metal melt and slag corrosion resistance and excellent alkali vapor corrosion resistance, and may be used as heat accumulating material for steel ladle and glass kiln, main material for stuffing in steel outlet of electric furnace, etc. and in cement kiln to replace partial periclase-magnesia spinel material. SkyAssociated with fayalite, forsterite has high impurity content, large burning loss and Fe₂O₃And Al₂O₃And the like form low-melting substances such as calcium forsterite, cordierite and the like at high temperature, and influence the high-temperature performance of the material.

The Chinese patent application CN 103044043A discloses a compact forsterite refractory raw material and a preparation method thereof, wherein the preparation method comprises the following steps: firstly, 69-85% of talcum powder, 10-30% of magnesium raw material fine powder containing one of electric smelting magnesia fine powder, sintering magnesia fine powder and light-burned magnesia powder and 0.2-2% of additive are mixed to prepare a mixture; then adding a bonding agent accounting for 1-10% of the mixture, ball-milling for 1-3 hours, adding 3-10% of water, stirring for 10-30 minutes, pressing a blank, drying, and calcining for 1-3 hours at the temperature of 1350-. The method mainly uses talcum, fused magnesia, sintered magnesia and light-burned magnesia, and Fe in talcum and magnesium raw material fine powder₂O₃CaO and Al₂O₃The impurity content is respectively less than 1.2 percent and 3 percent, the impurity content is higher, and low-temperature phases such as cordierite, fayalite, glass and the like are easily generated, thereby influencing the purity and the high-temperature performance of the product.

Chinese patent application CN 106187217 a discloses a method for preparing forsterite, which comprises the following steps: the method comprises the steps of grinding blast furnace slag serving as a raw material into powder, calcining and crushing the powder and aluminum powder in a calcining furnace, removing iron in the crushed powder by using a magnet, soaking the powder by using hydrochloric acid, filtering, drying filter residues, reacting the filter residues with a sodium hydroxide solution, removing residues, concentrating a filtrate, mixing the concentrated filtrate with magnesium oxide powder and attapulgite, carrying out melting carbonization, standing and cooling, and thus obtaining the forsterite. The method uses blast furnace slag as a raw material, has high impurity content, uses strong acid and strong alkali such as hydrochloric acid and sodium hydroxide in the manufacturing process, has multiple processes and high risk, and the synthesized forsterite has high impurity content.

Chinese patent application CN 104725057 a discloses medium-density forsterite sand and a preparation method thereof, wherein the preparation method comprises the following steps: taking 85-93% magnesite tailings to lightly burn for 0.5-5 hours at 1200-A mineral and quartz mix; then adding pore-forming agent accounting for 5-40% of the mixture and bonding agent accounting for 3-12% of the mixture in sequence, mixing, pressing by a pressure machine with pressure of 110-150MPa, drying, and roasting at 1650-1720 ℃ for 4-9 hours. The magnesite tailings contain a certain amount of CaO and Al₂O₃At high temperature with MgO and SiO₂And reacting to form low-temperature phases such as forsterite, cordierite and glass, which affect the purity and high-temperature performance of forsterite.

Disclosure of Invention

The invention aims to provide high-purity compact forsterite which has low impurity content, high forsterite purity, low porosity and high volume density. The invention also provides a simple, feasible, energy-saving and environment-friendly preparation method.

The preparation method of the high-purity compact forsterite is characterized by comprising the following components in percentage by mass: 50-65% of high-purity seawater magnesia, 35-50% of high-purity quartz sand and 0.1-3% of organic bonding agent.

The preparation method of the high-purity compact forsterite is characterized by comprising the following steps:

(1) weighing and mixing the high-purity seawater magnesite, the high-purity quartz sand and the organic bonding agent according to a set proportion.

(2) Putting the mixture into a ball mill, adding water accounting for 60 percent of the weight of the raw materials, and carrying out wet grinding until the median particle diameter D50 is less than or equal to 10 microns.

(3) The slurry is passed through a 325 mesh vibrating screen and a deironing device to remove iron.

(4) Filtering mud, vacuum refining mud, and extruding to form a block blank.

(5) Drying in a drying vehicle at 120 deg.C for 12 hr.

(6) Calcining at 1600-1700 deg.c for 8-16 hr.

The chemical composition requirements of the high-purity seawater magnesite are as follows: MgO is more than or equal to 99 percent, the purity of the synthesized forsterite is ensured, the amount of hydration reaction can be controlled, and the condition that the forsterite cannot be milled by wet grinding is prevented.

The high-purity quartz sand can be natural stoneQuartz or fused silica or a mixture of natural quartz and fused silica, wherein the chemical composition of the quartz sand is required to be as follows: SiO 2₂≥99%。

The additional organic binder is polyvinyl alcohol or carboxymethyl cellulose.

Compared with the prior art, the invention has the following beneficial effects:

the high-purity compact forsterite prepared by the method has the porosity of less than or equal to 3 percent, the volume density of more than or equal to 2.7g/cm3, extremely low impurity content and SiO₂The content of MgO is more than or equal to 99 percent, the content of other impurities is less than or equal to 1 percent, and the purity of the forsterite is high.

Detailed Description

The present invention is further illustrated by the following examples, which are not intended to limit the practice of the invention.