CN1974475A

CN1974475A - Making process of electrofused mullite

Info

Publication number: CN1974475A
Application number: CN 200610147651
Authority: CN
Inventors: 陈海; 王俊; 孙宝德
Original assignee: Shanghai Jiaotong University
Current assignee: Shanghai Jiaotong University
Priority date: 2006-12-21
Filing date: 2006-12-21
Publication date: 2007-06-06
Anticipated expiration: 2026-12-21
Also published as: CN100415679C

Abstract

The present invention relates to ceramic and refractory material technology, and is especially making process of electrofused mullite. The making process includes the following steps: 1. the waste aluminum ash pre-treating step comprising calcining waste aluminum ash at 1100 deg.c to convert partial Al into Al2O3, washing with hydrochloric acid and stoving; and 2. the electrofusing step comprising mixing aluminum ash 30-80 wt%, alum 0-50 wt% and silica 10-20 wt%, smelting in an arc furnace, cooling outside the furnace, crushing and sorting. The present invention has low production cost and can eliminate environmental pollution caused by waste aluminum ash.

Description

The manufacture method of electrofused mullite

Technical field

What the present invention relates to is the manufacture method of the method for a kind of pottery and technical field of refractory materials, particularly a kind of electrofused mullite.

Background technology

In recent years, China's aluminium industry fast development, the output sustainable growth has become the main aluminium producing country in the world.Produce a large amount of aluminium ash wastes during aluminium metallurgy, according to statistics, 1000 tons of aluminium of every production will produce the aluminium ash about 25 tons, only the annual aluminium scrap ash that just produces about 50,000 tons in area, Shanghai.Multiple channel has been developed in the regeneration of aluminium scrap ash in recent years, carries aluminium as secondary refining, synthesized polymer aluminum chloride (water purification agent) etc., but a large amount of aluminium scrap ashes is difficult to dispose, and above-mentioned treating processes easily produces secondary pollution.

Find through literature search prior art, Shi Zhenke etc. were " developing material and application " (2005, the 5th phase, the 14-16 page or leaf) delivered " additive is to the influence of the mullite crystal phase structure of aluminium manufacturer's industrial residue development ", propose to adopt sintering process to utilize aluminium ash and silica to be the raw material mullite synthesizing in this article, concrete grammar is: adopt aluminium ash and silica as raw material, fine silicon powder is as mineralizer, high temperature sintering prepared in reaction mullite.Its deficiency is: sintering process is a solid state reaction, is difficult to carry out fully, and is noncrystalline mutually more, can influence quality product, and manufacturing process is complicated.In further retrieving, finding no with the aluminium ash is the bibliographical information that raw material adopts electric smelting explained hereafter electrofused mullite.

Summary of the invention

The objective of the invention is at the problems referred to above, a kind of method of producing electrofused mullite has been proposed, making it adopt wasted aluminium ash is main raw material(s), be equipped with bauxitic clay and silica and produce the electrofused mullite material, both reduce the cost of mullite, consumed the wasted aluminium ash that causes environmental pollution easily again.

The present invention is achieved by the following technical solutions: the present invention includes: the pre-treatment of (1) aluminium ash, and main process comprises calcining and pickling; (2) aluminium ash, alumina and the silica raw material electric smelting process in electric arc furnace generates electrofused mullite.Concrete steps are:

(1) the first step is the preprocessing process of aluminium ash, aluminium ash major ingredient weight percent: Al ₂O ₃Content 26～35%, Al content 25～30%, SiO ₂Content 5～12%, MgO content 5～10%, TiO ₂Content is less than 3%, Fe ₂O ₃Content is less than 3%, Na ₂O content is less than 5%.Under 1100 ℃ of high temperature, carry out 3 hours calcination processing aluminium scrap ashes, make metal A l wherein partly be transformed into Al ₂O ₃, so that improve the content of aluminum oxide, obtain stable aluminium ash mixture, simultaneously, some volatile matters are by scaling loss.Aluminium ash after the calcining is put into tank, and the hydrochloric acid that adds weight percent 10～15% cleans twice, and each 20 minutes, to remove alkalimetal oxide and alkaline earth metal oxide.The aluminium ash of pickling is 200 ℃ of oven dry down.

(2) second steps were electric smelting processes, were raw material with pretreated aluminium ash, alumina and silica, alumina major ingredient weight percent: Al ₂O ₃Content 80～90%, SiO ₂Content 3～10%.SiO in the silica ₂Weight percent content is not less than 98%, adopts electric smelting explained hereafter mullite.Aluminium ash, alumina and silica are respectively the interior proportioning of scope of 30～80%:0～50%:10～20% by weight percentage, mix, and add in the electric arc furnace 1900～2100 ℃ of smelting temperatures, smelting time 60～90 minutes.Pour out cooling, broken pulverizing, sorting.

The present invention removes basic metal and alkaline earth metal oxide by the aluminium scrap ash is calcined and pickling, obtains the aluminium ash mixture of stable in properties, by allocating bauxitic clay and silica into, carries out electric smelting and obtains mullite material.The electric smelting method is a liquid phase reaction, reacts completely, and quality product is better, and mullite content can reach 95%, and the mullite content that the normal sintering method is produced is usually less than 90%.Mullite is having a wide range of applications aspect the refractory materialss such as ceramic kiln furniture.

Embodiment

Below embodiments of the invention are elaborated: present embodiment has provided detailed embodiment and process being to implement under the prerequisite with the technical solution of the present invention, but protection scope of the present invention is not limited to following embodiment.

Embodiment 1:

Aluminium ash major ingredient: Al ₂O ₃Content 30.56%, Al content 29.58%, SiO ₂Content 10.21%, MgO content 5.34%, TiO ₂Content 2.42%, Fe ₂O ₃Content 2.23%, Na ₂O content 4.74%.Bauxitic clay Al ₂O ₃Content 88.56%, SiO ₂Content 6.51%.SiO in the silica ₂Content 98.30%.

The aluminium ash is 1100 ℃ of down calcinings after 3 hours, cleans twice under the room temperature in adding the tank of 10% hydrochloric acid, stirs 200 ℃ of oven dry 20 minutes at every turn.80% and 20% take by weighing 120 kg aluminium ash, 30 kilograms of silicas respectively by weight percentage, do not add alumina, electric smelting is 60 minutes under 1950～2100 ℃ of high temperature, pours out cooling, broken pulverizing, sorting.

Resulting electrofused mullite content 91.4%.

Embodiment 2:

Aluminium ash major ingredient: Al ₂O ₃Content 34.87%, Al content 26.52%, SiO ₂Content 9.23%, MgO content 5.62%, TiO ₂Content 1.67%, Fe ₂O ₃Content 2.62%, Na ₂O content 4.53%.Bauxitic clay Al ₂O ₃Content 85.20%, SiO ₂Content 8.01%.SiO in the silica ₂Content 98.30%.

The aluminium ash is 1100 ℃ of down calcinings, cleans twice under the room temperature in adding the tank of 12% hydrochloric acid, stirs 200 ℃ of oven dry 20 minutes at every turn.40%, 50% and 10% take by weighing 60 kilograms of aluminium ashes, 75 kilograms of alumina and 15 kilograms of silicas respectively by weight percentage, electric smelting is 75 minutes under 1900～2100 ℃ of high temperature, pours out cooling, broken pulverizing, sorting.

Resulting electrofused mullite content 90.3%.

Embodiment 3:

Aluminium ash major ingredient: Al ₂O ₃Content 34.87%, Al content 26.52%, SiO ₂Content 9.23%, MgO content 5.62%, TiO ₂Content 1.67%, Fe ₂O ₃Content 2.62%, Na ₂O content 4.53%.Bauxitic clay Al ₂O ₃Bauxitic clay Al ₂O ₃Content 88.56%, SiO ₂Content 6.51%.SiO in the silica ₂Content 98.3%.

The aluminium ash cleans twice under the room temperature in the hydrochloric acid tank of adding 15% after calcining under 1000 ℃, stirred 200 ℃ of oven dry 20 minutes at every turn.50%, 35% and 15% take by weighing 75 kilograms of aluminium ashes, 52.5 kilograms of alumina and 22.5 kilograms of silicas respectively by weight percentage, electric smelting is 90 minutes under 1950～2100 ℃ of high temperature, pours out cooling, broken pulverizing, sorting.

Resulting electrofused mullite content 92.8%.

Claims

1, a kind of manufacture method of electrofused mullite is characterized in that, concrete steps are:

(1) the first step is the preprocessing process of aluminium ash, and calcination processing aluminium scrap ash makes metal A l wherein partly be transformed into Al ₂O ₃, the aluminium ash after the calcining is put into tank, add hydrochloric acid and clean, remove alkalimetal oxide and alkaline earth metal oxide, the aluminium ash oven dry of pickling;

(2) second steps were electric smelting processes, were raw material with aluminium ash, alumina and silica, and aluminium ash, alumina and silica are respectively 30～80%: 0～50% by weight percentage: proportioning in 10～20% the scope mixes, add in the electric arc furnace, cooling is poured out in melting, the broken pulverizing, sorting obtains mullite.

2, the manufacture method of electrofused mullite according to claim 1 is characterized in that, described calcining is carried out under 1100 ℃.

3, according to the manufacture method of claim 1 or 2 described electrofused mullites, it is characterized in that, described calcining, its time is 3 hours.

4, the manufacture method of electrofused mullite according to claim 1 is characterized in that, described adding hydrochloric acid cleans, and is meant: the hydrochloric acid that adds weight percent 10～15% cleans twice, each 20 minutes.

5, the manufacture method of electrofused mullite according to claim 1 is characterized in that, described oven dry, and its temperature is 200 ℃.

6, the manufacture method of electrofused mullite according to claim 1 is characterized in that, described aluminium ash, wherein Al ₂O ₃Content 26～35%, Al content 25～30%, SiO ₂Content 5～12%, MgO content 5～10%, TiO ₂Content is less than 3%, Fe ₂O ₃Content is less than 3%, Na ₂O content is less than 5%, and content is weight percent content herein.

7, the manufacture method of electrofused mullite according to claim 1 is characterized in that, described alumina, wherein Al ₂O ₃Weight percent content is 80～90%, SiO ₂Weight percent content is 3～10%.

8, the manufacture method of electrofused mullite according to claim 1 is characterized in that, described silica, wherein SiO ₂Weight percent content is more than or equal to 98%.

9, the manufacture method of electrofused mullite according to claim 1 is characterized in that, described melting, 1900～2100 ℃ of its temperature.

10, according to the manufacture method of claim 1 or 9 described electrofused mullites, it is characterized in that described melting, 60～90 minutes its time.