阅读说明：本技术 复合绝缘子用活性超细氢氧化铝的制备方法 (Preparation method of active superfine aluminum hydroxide for composite insulator ) 是由 王春风 窦志炜 于 2020-05-08 设计创作，主要内容包括：本发明公开了复合绝缘子用活性超细氢氧化铝的制备方法,包括以下步骤：S1：碱石灰烧结法；S1包括以下步骤：S101：将含铝原料、石灰石和纯碱球磨混合均匀,制得合格的生料；S102：生料在高温下烧结,制得烧结熟料；S103：烧结熟料溶出；S104：不溶物进入赤泥分离及洗涤；S105：粗液脱硅；S106：精液碳酸化分解；S107：氢氧化铝分离与洗涤；S108：氢氧化铝煅烧；S109：碳分解母液蒸发浓缩；S2：烧碱法制备后,要使氢氧化铝干燥脱水,然后粉碎得到超细氢氧化铝；S3：加有机硅对超细氢氧化铝进行改性处理,最终得到产品。本发明制得的活性超细氢氧化铝能改善无机阻燃剂与有机体的相溶性,它清合力好,增强性能高,击穿性能达到23以上,憎水性能HC1级。(The invention discloses a preparation method of active superfine aluminum hydroxide for a composite insulator, which comprises the following steps: s1: soda lime sintering; s1 includes the steps of: s101: ball-milling and uniformly mixing the aluminum-containing raw material, limestone and soda ash to prepare qualified raw materials; s102: sintering the raw material at high temperature to prepare sintered clinker; s103: dissolving out the sintering clinker; s104: separating and washing insoluble substances in red mud; s105: desiliconizing the crude liquid; s106: carbonating and decomposing the semen; s107: separating and washing aluminum hydroxide; s108: calcining aluminum hydroxide; s109: evaporating and concentrating the carbon decomposition mother liquor; s2: after the preparation by the caustic soda method, drying and dehydrating the aluminum hydroxide, and then crushing to obtain superfine aluminum hydroxide; s3: adding organic silicon to modify the superfine aluminum hydroxide to finally obtain the product. The active superfine aluminium hydroxide prepared by the invention can improve the compatibility of inorganic flame retardant and organism, and has good cleaning power, high reinforcing performance, breakdown performance of more than 23 and hydrophobic performance of HC1 grade.)

1. The preparation method of the active superfine aluminum hydroxide for the composite insulator is characterized by comprising the following steps: the method comprises the following steps:

s1: soda lime sintering;

s1 includes the steps of:

s101: ball-milling and uniformly mixing the aluminum-containing raw material, limestone and soda ash to prepare qualified raw materials;

s102: sintering the raw material at high temperature to prepare sintered clinker;

s103: dissolving out the sintering clinker;

s104: separating and washing insoluble substances in red mud;

s105: desiliconizing the crude liquid;

s106: carbonating and decomposing the semen;

s107: separating and washing aluminum hydroxide;

s108: calcining aluminum hydroxide;

s109: evaporating and concentrating the carbon decomposition mother liquor;

s2: after the preparation by the caustic soda method, drying and dehydrating the aluminum hydroxide, and then crushing to obtain superfine aluminum hydroxide;

s3: adding organic silicon to modify the superfine aluminum hydroxide to finally obtain the product.

2. The method for preparing the active ultrafine aluminum hydroxide for the composite insulator according to claim 1, wherein the method comprises the following steps: in the step S1: the liquid-solid ratio of the raw material is 2.5 +/-0.2, the calcium ratio is 2.0, the alkali ratio is 1.0-1.3, the solid-solid ratio of the dissolution liquid is 2.0, the aluminum-silicon ratio is 4.4 +/-0.2, and the iron-aluminum ratio is 0.08-1.0.

3. The method for preparing the active ultrafine aluminum hydroxide for the composite insulator according to claim 1, wherein the method comprises the following steps: in the step S101: the aluminum-containing raw material is one or more of nepheline ore, alunite ore, fly ash, coal gangue and bauxite.

4. The method for preparing the active ultrafine aluminum hydroxide for the composite insulator according to claim 1, wherein the method comprises the following steps: in the step S102: the sintering temperature of the raw material sintering at high temperature is 1000-1200 ℃.

5. The method for preparing the active ultrafine aluminum hydroxide for the composite insulator according to claim 1, wherein the method comprises the following steps: in the step S101: the limestone can be replaced by calcium lime or carbide slag.

6. The method for preparing the active ultrafine aluminum hydroxide for the composite insulator according to claim 1, wherein the method comprises the following steps: in the step S101: the soda ash can be replaced by residual carbon content mother liquor in the process of preparing aluminum hydroxide by carbonating and decomposing sodium carbonate hydrate or sodium aluminate solution.

Technical Field

The invention relates to the technical field of aluminum hydroxide preparation, in particular to a preparation method of active ultrafine aluminum hydroxide for a composite insulator.

Background

The composite insulator is mainly used for telegraph poles in the early years, and along with the rapid development of science and technology, a plurality of disc-shaped insulators are hung at one end of a high-voltage wire connecting tower, which is developed to increase the creepage distance.

The composite insulator plays two basic roles in an overhead transmission line, one is to support a lead, and the other is to prevent current from flowing back to the ground, the two roles are ensured, the composite insulator cannot fail due to various electromechanical stresses caused by changes of environmental and electrical load conditions, otherwise, the insulator cannot play a great role, and the service life of the whole line are damaged.

The composite insulator is composed of three parts of shed sheath, glass fibre reinforced plastic core rod and end hardware fitting. The shed sheath or the jacket or the umbrella cover is an outer insulator of the insulator and is used for providing necessary creepage distance and protecting the core rod from the weather.

The outer casing of the composite insulator may be made of a variety of materials: the composite insulator shed rubber is prepared by the steps of mixing, hot refining, vulcanizing, coloring and back refining of silicon rubber, white carbon black, inorganic insulating filler, auxiliary agent, vulcanizing agent, coloring agent and the like, then the raw materials are sequentially subjected to batching, mixing, hot refining and back refining to prepare the composite rubber for the shed protective sleeve, and then the composite rubber is subjected to injection or injection molding, and subjected to two-stage vulcanization, end assembly and end sealing to obtain the shed of the composite insulator.

The composite insulator outer sleeve has good performances of high and low temperature resistance, sunlight and ultraviolet irradiation resistance, ozone oxidation resistance, mildew breeding resistance and the like, but the composite insulator outer sleeve has the defects of low mechanical strength, low electric corrosion resistance, poor protective performance and the like generally, so that the long-term safe operation of the composite insulator outer sleeve is difficult to guarantee, the importance of an inorganic insulating filler which is one of composite insulator outer sleeve materials is reflected, and the electrical performance of the composite insulator outer sleeve is improved by adding various inorganic insulating fillers.

The aluminum hydroxide is an inorganic flame retardant additive with the largest dosage and the widest application, and is also a common electric corrosion resistant filler in the external insulation of the composite insulator at home and abroad at present. The aluminum hydroxide serving as a flame retardant can not only resist flame, but also prevent fuming, does not produce dripping and does not produce toxic gas, so that the aluminum hydroxide is widely applied, the usage amount is increased year by year, and the aluminum hydroxide is one of the main raw materials of the composite insulator.

However, when the electrical property of the aluminum hydroxide used in the composite insulator jacket is enhanced, the compatibility, the cleaning force, the breakdown performance, the later hydrophobic migration and other performances of the inorganic flame retardant and the organic matter are weakened, so that the long-term running performance of the product cannot be guaranteed.

In view of this, the main product of our department, active superfine aluminium hydroxide, is the advanced high-voltage flame-retardant insulating filling material internationally at present, it is mainly suitable for high-voltage insulators, high-voltage wires, in the compound insulator rubber compound, it can improve various properties, can improve the intermiscibility of inorganic flame retardant and organism, it is clear and powerful, the breakdown performance reaches more than 23, the hydrophobic performance is HC1 grade. The active superfine aluminium hydroxide produced by the department of China is supplied to high-voltage line conforming material insulators and electrified railway conforming insulators of large-scale enterprises under national grids and railways. The silicone rubber umbrella sleeve formed by integral injection has good hydrophobicity and friendship electrical insulation performance, after 5000-hour artificial accelerated aging test, the electromechanical performance of the silicone rubber umbrella sleeve has no obvious change, the excellent ozone resistance and aging resistance of the silicone rubber umbrella sleeve are fully displayed, and the silicone rubber umbrella sleeve is a reliable guarantee for effectively preventing insulator pollution flashover faults.

Disclosure of Invention

The invention aims to provide a preparation method of active superfine aluminum hydroxide for a composite insulator, which overcomes the defects of the prior art and solves the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: the preparation method of the active superfine aluminum hydroxide for the composite insulator comprises the following steps:

s1: soda lime sintering;

s1 includes the steps of:

s101: ball-milling and uniformly mixing the aluminum-containing raw material, limestone and soda ash to prepare qualified raw materials;

s102: sintering the raw material at high temperature to prepare sintered clinker;

s103: dissolving out the sintering clinker;

s104: separating and washing insoluble substances in red mud;

s105: desiliconizing the crude liquid;

s106: carbonating and decomposing the semen;

s107: separating and washing aluminum hydroxide;

s108: calcining aluminum hydroxide;

s109: evaporating and concentrating the carbon decomposition mother liquor;

s2: after the preparation by the caustic soda method, drying and dehydrating the aluminum hydroxide, and then crushing to obtain superfine aluminum hydroxide;

s3: adding organic silicon to modify the superfine aluminum hydroxide to finally obtain the product.

Preferably, in step S1: the liquid-solid ratio of the raw material is 2.5 +/-0.2, the calcium ratio is 2.0, the alkali ratio is 1.0-1.3, the solid-solid ratio of the dissolution liquid is 2.0, the aluminum-silicon ratio is 4.4 +/-0.2, and the iron-aluminum ratio is 0.08-1.0.

Preferably, in step S101: the aluminum-containing raw material is one or more of nepheline ore, alunite ore, fly ash, coal gangue and bauxite.

Preferably, in step S102: the sintering temperature of the raw material sintering at high temperature is 1000-1200 ℃.

Preferably, in step S101: the limestone can be replaced by calcium lime or carbide slag.

Preferably, in step S101: the soda ash can be replaced by residual carbon content mother liquor in the process of preparing aluminum hydroxide by carbonating and decomposing sodium carbonate hydrate or sodium aluminate solution.

Compared with the prior art, the invention has the following beneficial effects: the active superfine aluminium hydroxide prepared by the invention can improve the compatibility of inorganic flame retardant and organism, and has good cleaning power, high reinforcing performance, breakdown performance of more than 23 and hydrophobic performance of HC1 grade.

Drawings

FIG. 1 is a flow chart of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, the present invention provides a technical solution: the preparation method of the active superfine aluminum hydroxide for the composite insulator comprises the following steps:

s1: soda lime sintering;

s1 includes the steps of:

s101: ball-milling and uniformly mixing the aluminum-containing raw material, limestone and soda ash to prepare qualified raw materials;

s102: sintering the raw material at high temperature to prepare sintered clinker, reacting alumina in the aluminum raw material with added soda ash to form solid sodium aluminate which is easily dissolved in water or dilute alkali, and simultaneously enabling impurities such as silicon, iron, titanium and the like to generate calcium orthosilicate, sodium ferrite, calcium titanate and the like;

s103: dissolving out the sintering clinker;

s104: separating and washing insoluble substances in the red mud, dissolving out sodium oxide and aluminum oxide in clinker by using a regulating solution to obtain a sodium aluminate solution, and separating the sodium aluminate solution from insoluble residues such as calcium orthosilicate, sodium ferrite, calcium titanate and the like entering the red mud;

s105: desiliconizing the crude liquid, carrying out special desiliconization purification on the dissolution liquid (crude liquid) of the clinker, and carbonizing the desiliconized refined liquid to produce alumina;

s106: the refined solution is carbonated and decomposed, after the crude solution is subjected to desiliconization treatment, the solution contains a large amount of silicon slag, red mud and other impurities, the impurities cannot be directly decomposed, and in order to enable the product alumina to meet the national specified standard, the crude solution must be clarified and separated after being subjected to desiliconization to prepare a pure and transparent sodium aluminate solution. In the treatment of the desiliconized solution, a leaf filter or a filter press is generally used in industry for separating the silica residue in the desiliconized solution. The silicon slag separation process is to separate the desiliconized slurry from the desiliconization process to obtain sodium aluminate concentrate with desiliconized index, Fe/Al ratio and suspended matter content meeting technological requirement, and the concentrate is sent to carbonating decomposition. The quality of the refined solution is the key for ensuring the quality of the final product alumina;

s107: the separation and washing of aluminum hydroxide are different according to different washing methods of the production method. Such as direct precipitation and carbonation, the aluminum hydroxide that comes out is morphologically different. Basically, the water is heated to more than 40 ℃ by clear water for vacuum filtration and washing;

s108: and calcining the aluminum hydroxide, wherein the calcining of the aluminum hydroxide refers to a process of heating the aluminum hydroxide to a certain temperature below the melting point of the aluminum hydroxide so as to convert the aluminum hydroxide into finished aluminum hydroxide. Calcining in a rotary kiln or a fluidized bed calcining furnace, and converting into aluminum hydroxide with the qualified quality after a series of changes such as drying, dehydration, phase change and the like;

s109: evaporating and concentrating the carbon decomposition mother liquor, and returning the concentrated carbon decomposition mother liquor to the ingredient;

s2: after the preparation by the caustic soda method, drying and dehydrating the aluminum hydroxide, and then crushing to obtain superfine aluminum hydroxide;

s3: adding organic silicon to modify the superfine aluminum hydroxide to finally obtain the product.

The soda lime sintering method comprises nine procedures, namely S101-S109, and six ratios, namely a raw material liquid-solid ratio, a calcium ratio, a soda ratio, a dissolving liquid-solid ratio, an aluminum-silicon ratio and an iron-aluminum ratio.

Further, in the step S1: the liquid-solid ratio of the raw material is 2.5 +/-0.2, the calcium ratio is 2.0, the alkali ratio is 1.0-1.3, the solid-solid ratio of the dissolution liquid is 2.0, the aluminum-silicon ratio is 4.4 +/-0.2, and the iron-aluminum ratio is 0.08-1.0.

Further, in the step S101: the aluminum-containing raw material is one or more of nepheline ore, alunite ore, fly ash, coal gangue and bauxite.

Further, in the step S102: the sintering temperature of the raw material sintering at high temperature is 1000-1200 ℃.

Further, in the step S101: the limestone can be replaced by calcium lime or carbide slag.

Further, in the step S101: the soda ash can be replaced by residual carbon content mother liquor in the process of preparing aluminum hydroxide by carbonating and decomposing sodium carbonate hydrate or sodium aluminate solution.

The active superfine aluminium hydroxide prepared by the invention can improve the compatibility of inorganic flame retardant and organism, and has good cleaning power, high reinforcing performance, breakdown performance of more than 23 and hydrophobic performance of HC1 grade.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.