CN1522957A

CN1522957A - Production method for ultra-fine silicon micronized quartz powder

Info

Publication number: CN1522957A
Application number: CNA031509126A
Authority: CN
Inventors: 潘安芳
Original assignee: HUZHOU WANNENG SILICON MICROPOWDER FACTORY
Current assignee: HUZHOU WANNENG SILICON MICROPOWDER FACTORY
Priority date: 2003-09-09
Filing date: 2003-09-09
Publication date: 2004-08-25

Abstract

The present invention relates to a production method of superfine silicon micropowder. Said method includes the steps of crushing high-quality silicon raw material, washing with water, magnetic separation, acid washing to remove iron impurity, wet ball grinding, naturally precipitating slurry obtained by ball-grinding process and separating precipitate. The invented key lies in that in the ball-grinding slurry suspension obtained after the precipitate is separated out, a preciptant is added and stood still for several hr., then the upper clear liquor is separated out, and the lower precipitated slurry can be fed into press filter to make filter pressing operation, then the filter press cave is dried and pulverized so as to obtain the superfine silicon dioxide micropowder whose grain size is 1.0-0.1 micrometer.

Description

A kind of production method of super-fine silicon micro-powder

Technical field

The present invention relates to the preparation method of superfine silicon dioxide.

Background technology

Good physics-chem characteristics such as that silicon-dioxide has is high temperature resistant, acid and alkali-resistance, thermal expansivity are little, high-insulativity, piezoelectric effect, resonance effect, therefore, fine silica powder is widely used in the electron and electrician products such as Chemicals such as paint, coating, rubber, plastics, Resins, epoxy, advanced ceramic and computer chip, photoconductive fiber, insulated electrical equipment material.The quality of fine silica powder product, not only relevant with its purity, and also closely related with its particle fineness, its purity is high more, and particle is thin more, and its application quality is high more, and range of application is wide more.At present, the production method of fine silica powder product has physics method and chemical method.Conventional physics method is to adopt that ball mill is done, wet ball grinding, it generally can only process 〉=and the silicon powder of 2 μ m fineness, and the product cut size wider distribution, particle is even inadequately; And will produce＜super-fine silicon micro-powder of 1.0 μ m particle diameters, generally all adopting chemical method, its complex process needs specific installation, and the production cost height also easily brings environmental pollution.

Summary of the invention

Purpose of the present invention, it is simple to provide a kind of technology, and production cost is low, and it is the superfine silicon dioxide micro mist of 1.0-0.1 μ m that physical refining processes low in the pollution of the environment comes the production granularity.

Method of the present invention comprises conventional ball milled production technique, is about to the high-quality silica raw material and removes iron contamination through coarse reduction, washing, magnetic separation, pickling; Wet ball grinding; The natural sedimentation of ball milling slurry; Isolate throw out---fine silica powder; Its invention main points are in the pulp suspension after branch is left away throw out, to add precipitation agent; Divide the top clear liquor of leaving away after leaving standstill a few hours, slurry is precipitated in the bottom send the pressure filter press filtration; The filter cake oven dry is pulverized; Promptly make the superfine silicon dioxide micro mist.

The present invention is actually and utilizes former wet ball grinding to produce the pulp suspension of the discarded discharging of silicon powder process, therefrom extracts super-fine silicon micro-powder.Its technology is simple, and production cost is low, both turns waste into wealth, and has solved the discarded discharging of former pulp suspension again and has caused environmental pollution problems.

Embodiment

The concrete production craft step of present embodiment is:

(1) pickling iron impurity

Select SiO for use ₂Content is that 100 order quartz sands more than 99.5% are raw material, and quartz sand surface dust impurity is removed in washing earlier, and the acid dipping of processing industry salt is about 72 hours then, and the venting acid solution is clean with the clear water rinsing;

(2) wet ball grinding

With clean quartz sand release grinding machine wet ball grinding to about 600 order thicknesses;

(3) iron removal by magnetic separation

The ball milling slurry is removed free iron impurity by magnetic separator;

(4) slurry sediment

SiO after the magnetic separation ₂The ball milling slurry send first pretipitatin jar natural sedimentation 20-24 hour;

(5) primary products

Isolate SiO ₂The slurry sediment thing, oven dry obtains about 600 purpose SiO ₂Micro mist;

(6) suspension redeposition

The suspension of first pretipitatin jar is delivered to second pretipitatin jar, allow its natural sedimentation about 24 hours;

(7) wet method correct grinding

Isolate SiO from second pretipitatin jar ₂Micro mist precipitation (about 2000-3000 order) release grinding machine wet method was finish grinded about 48 hours, and the correct grinding meson adopts high-purity white quartz stone of φ 10-30mm, correct grinding back SiO ₂Slurry send the 3rd pretipitatin jar;

(8) secondary product

Correct grinding SiO ₂Slurry is isolated throw out after the 3rd pretipitatin jar precipitation is more than 48 hours, oven dry obtains about 4000-5000 purpose SiO ₂The micro mist product;

(9) add the precipitation agent precipitation

The isolated suspension of second, third pretipitatin jar is delivered to the 4th pretipitatin jar respectively and is mixed, and adds precipitation agent AlCl ₃(ratio is 500g/m ³About), staticly settle about 12 hours;

(10) press filtration

Venting the 4th pretipitatin jar top primary water, bottom precipitation slurry send the pressure filter press filtration;

(11) ultra-fine SiO ₂Product

Filter cake oven dry, pulverizing, promptly getting granularity is the SiO of 1.0-0.1 μ m (meta particle diameter 0.5 μ m) ₂Ultra-fine micropowder, its SiO ₂Content 〉=98.8%, Fe ₂O ₃≤ 0.01%.

Claims

1, a kind of production method of super-fine silicon micro-powder, comprise the high-quality silica raw material is removed iron contamination through coarse reduction, washing, magnetic separation, pickling, wet ball grinding, processing steps such as throw out are isolated in the natural sedimentation of ball milling slurry, it is characterized in that in the ball milling pulp suspension after branch is left away throw out, add precipitation agent, divide the top clear liquor of leaving away after leaving standstill a few hours, slurry is precipitated in the bottom send the pressure filter press filtration, the filter cake oven dry is pulverized, and promptly makes the superfine silicon dioxide micro mist.

2, by the production method of the described a kind of super-fine silicon micro-powder of claim 1, it is characterized in that preferred production craft step is:

(1) pickling iron impurity: select SiO for use ₂Content is that the quartz sand more than 99.5% is raw material, and quartz sand surface dust impurity is removed in washing earlier, and the acid dipping of processing industry salt is tens of hours then, and the venting acid solution is clean with the clear water rinsing;

(2) wet ball grinding: with clean quartz sand release grinding machine wet ball grinding to about 600 order thicknesses;

(3) iron removal by magnetic separation: the ball milling slurry is removed free iron by magnetic separator;

(4) slurry natural sedimentation: the ball milling slurry after the magnetic separation send first pretipitatin jar natural sedimentation 20-24 hour;

(5) primary products: isolate the slurry sediment thing of first pretipitatin jar, oven dry obtains about 600 purpose SiO ₂Micro mist;

(6) suspension redeposition: the suspension of first pretipitatin jar is delivered to second pretipitatin jar, allow its natural sedimentation about 24 hours;

(7) wet method correct grinding: isolate SiO from second pretipitatin jar ₂Micro mist precipitation (about 2000-3000 order) release grinding machine wet method was finish grinded about 48 hours, and the correct grinding disposed slurry send the 3rd pretipitatin jar;

(8) secondary product: correct grinding SiO ₂Slurry is isolated throw out after the 3rd pretipitatin jar precipitation is more than 48 hours, oven dry obtains about 4000-5000 purpose SiO ₂The micro mist product;

(9) add the precipitation agent precipitation: the isolated suspension of second, third pretipitatin jar is delivered to the 4th pretipitatin jar and is mixed, and adds precipitation agent, staticly settles a few hours;

(10) press filtration: venting the 4th pretipitatin jar top primary water, bottom precipitation slurry send the pressure filter press filtration;

(11) ultra-fine SiO ₂Product: filter cake oven dry, pulverizing, promptly getting granularity is the SiO of 1.0-0.1 μ m (meta particle diameter 0.5 μ m) ₂Ultra-fine micropowder, its SiO2 content 〉=98.8%, FeO ₃≤ 0.01%.

3,, it is characterized in that the correct grinding meson of wet method correct grinding is high-purity white quartz stone of φ 10-30mm by the production method of the described a kind of super-fine silicon micro-powder of claim 2.

4, by the production method of claim 1 or 2 described a kind of super-fine silicon micro-powders, it is characterized in that preferred precipitation agent is AlCl ₃

5, by the production method of the described a kind of super-fine silicon micro-powder of claim 4, it is characterized in that AlCl ₃Precipitation agent is at SiO ₂Preferred adding proportion in the micro mist suspension is 500g/m ³