CN104785789A

CN104785789A - Silicon-mixed tungsten powder preparation process

Info

Publication number: CN104785789A
Application number: CN201510177517.2A
Authority: CN
Inventors: 易鉴荣; 林荔琍; 唐臻; 吴坚
Original assignee: Liuzhou Haoxiangte Technology Co Ltd
Current assignee: Liuzhou Haoxiangte Technology Co Ltd
Priority date: 2015-04-16
Filing date: 2015-04-16
Publication date: 2015-07-22

Abstract

The invention relates to a silicon-mixed tungsten powder preparation process. The process includes the steps that Na2WO4.5H2O is dissolved in distilled water and ethyl orthosilicate is added; a hydrochloric acid solution is dropped and components are magnetically stirred and evenly mixed; a mixed solution is placed in a high-pressure reaction kettle to be heated and react; the mixed solution is cooled to the indoor temperature and filtered, and sediment is acquired; the sediment is washed and dried; the dried sediment is placed in a muffle furnace so as to be burnt, and tungsten trioxide and silicon oxide powder is acquired; tungsten trioxide and silicon oxide powder is placed in a plasma reaction chamber, inert gas is ionized in the reaction chamber to generate high-temperature plasma, and after being heated through the high-temperature plasma, the tungsten trioxide and silicon oxide powder is reduced to tungsten-silicon powder under a reducing atmosphere. By the adoption of the process, tungsten oxide and silicon oxide are prepared through sodium tungstate, the ethyl orthosilicate and hydrochloric acid, the tungsten-silicon powder is prepared through a plasma electric arc method, due to the fact that the large temperature difference exists between the tungsten-silicon powder and a cooling medium, crystal nucleus growth is effectively restrained in the nucleation promoting process, and the acquired tungsten-silicon powder can reach the nanoscale.

Description

A kind of preparation technology mixing silicon tungsten powder

Technical field

The present invention relates to the preparation technology of tungsten silicon powder.

Background technology

In the Extraction metallurgy of tungsten silicon, the importance that tungsten and silica flour are produced is apparent, and the performance of tungsten silica flour affects the performance of tungsten product to a great extent.The quality of tungsten silica flour is the guarantee to tungsten silicon and tungsten silicon alloy superior function, the industry of tungsten silica flour faces great challenge, it must meet the market requirement more and more high to it, the production of tungsten silica flour is not only had to the requirement of chemical purity aspect, and having the requirement of physical property and processing performance aspect, the technology of preparing especially meeting the ultrafine tungsten silica flour of some specific uses need to solve.

The technique of producing tungsten silica flour is a lot, adopts silica and tungstic acid to be that to prepare tungsten silica flour by hydrogen reduction reaction be wherein a kind of to raw material; Traditional Process of Hydrogen Reduction flow process is the tungstic acid and silica that raw material roasting are obtained, then obtains tungsten silica flour through two stage of reduction, uses traditional handicraft to prepare tungsten silica flour and there is following problems: 1, reduction temperature is low, and the reaction time is long, time-consuming; 2, adopt tubulose reduction furnace, equipment is complicated, not energy-conservation; 3, product purity is low, more difficult continuous prodution.

Summary of the invention

For above-mentioned technical problem, the invention provides the technique preparing tungsten silica flour that a kind of preparation time is short, easily accomplish scale production.

The present invention solves the problems of the technologies described above adopted technical scheme: a kind of preparation technology mixing silicon tungsten powder, and it comprises the following steps:

(1) by Na ₂wO ₄5H ₂o is dissolved in distilled water, adds ethyl orthosilicate;

(2) drip hydrochloric acid solution again, magnetic agitation mixes;

(3) mixed solution is placed in autoclave and adds thermal response;

(4) filter after being cooled to room temperature again, be precipitated thing; Washing precipitate, and dry;

(5) sediment of oven dry is put into Muffle furnace calcination, obtain tungstic acid and silica powder;

(6) tungstic acid and silica powder are placed in plasma reaction chamber, in this reative cell, form high-temperature plasma by ionization inert gas, after tungstic acid and silica powder are heated by high-temperature plasma, be reduced into tungsten silica flour under reducing atmosphere.

As preferably, described Na ₂wO ₄5H ₂the ratio of O, ethyl orthosilicate, hydrochloric acid is 1:(0.1-0.15): (0.1-0.5).

As preferably, the heating-up temperature of reactor is 80 DEG C--120 DEG C, the reaction time is 20h-24h.

As preferably, during washing, adopt distilled water and absolute ethyl alcohol cyclic washing.

As preferably, during oven dry, adopt 50 DEG C--dry 8h-10h for 70 DEG C.

As preferably, in Muffle furnace, adopt 400 DEG C--the temperature calcination 2h-4h of 500 DEG C.

As preferably, plasma reaction is indoor is plasma working gas with argon gas, and hydrogen is reducing atmosphere; With tungstic acid and silica powder for positive pole, plasma gun is negative pole, the electric arc ionization inert gas produced between a positive electrode and a negative electrode after energising, thus forms high-temperature plasma to tungstic acid and silica powder heating.

As preferably, operating voltage during energising is 60v--90v, and operating current is 400A--700A.

As preferably, be 1000 DEG C to the heating-up temperature of tungstic acid and silica powder--1800 DEG C.

As can be known from the above technical solutions, after this technique adopts sodium tungstate, ethyl orthosilicate and hydrochloric acid to prepare tungsten oxide and silica, by plasma-arc legal system for tungsten silica flour, owing to having very large temperature difference between tungsten silica flour and cooling medium, while impelling forming core, also effectively inhibit the growth of nucleus, obtained tungsten silica flour can reach nanoscale; Meanwhile, this technology process is comparatively simple, and preparation time is shorter, easily accomplish scale production.

Detailed description of the invention

Introduce the preparation technology of tungsten silica flour in detail below in conjunction with embodiment, it carries out according to the following steps:

First, by Na ₂wO ₄5H ₂o is dissolved in distilled water, adds ethyl orthosilicate, more slowly drips hydrochloric acid solution, and solution, under magnetic stirring after magnetic agitation, is placed in autoclave, reactor is put into 80 DEG C by room temperature--and the baking oven of 120 DEG C reacts 20h-24h; Be cooled to room temperature after reaction, filter and be precipitated thing, and with distilled water, absolute ethyl alcohol cyclic washing sediment; Wherein, Na ₂wO ₄5H ₂the ratio of O, ethyl orthosilicate, hydrochloric acid thinks 1:(0.1-0.15): (0.1-0.5) is advisable.

Then, the sediment after washing is put into 50 DEG C--70 DEG C of dry 8h-10h of baking oven; The sediment of oven dry is put into 400 DEG C--the Muffle furnace calcination 2h-4h of 500 DEG C, obtained nano tungsten trioxide and silica superfine powder.

Then, tungstic acid and silica powder are placed in plasma reaction chamber, plasma reaction is indoor is plasma working gas with argon gas, and hydrogen is reducing atmosphere, with tungstic acid and silica powder for positive pole, plasma gun is negative pole, operating voltage is 60v--90v, operating current is 400A--700A, the electric arc ionization inert gas produced between a positive electrode and a negative electrode, thus form high-temperature plasma to tungstic acid and silica powder heating, heating-up temperature maintains 1000 DEG C--between 1800 DEG C, tungstic acid and silica powder are steam by high-temperature plasma heating and gasifying, high-temperature steam is reduced into tungsten silica flour under the effect of reducing atmosphere hydrogen, and under the cooling effect of reactor interlayer taking circulating water as cooling medium, spontaneous nucleation, cohesion forms the nano particle mixing silicon tungsten powder, and fall in gathering-device.

Embodiment 1

Get 600gNa ₂wO ₄5H ₂o is dissolved in 2L distilled water, adds 60mL ethyl orthosilicate; 60g hydrochloric acid is configured to solution, slowly drops in above-mentioned solution, room temperature lower magnetic force stirs 30min; Stir and be placed in the autoclave of inner liner polytetrafluoroethylene, baking oven reactor being put into 80 DEG C reacts 24h; Be cooled to room temperature after reaction, filter and use distilled water, absolute ethyl alcohol cyclic washing sediment; Gained precipitation puts into 50 DEG C of dry 10h of baking oven, then puts into the Muffle furnace calcination 4h of 400 DEG C; Then powder is placed in plasma reaction chamber, take operating voltage as 60v, operating current is the electric arc ionization argon gas that the condition of 400A produces, and plasma maintains about 1000 DEG C to tungstic acid and silica powder heating-up temperature, and the silicon tungsten powder average grain diameter of mixing obtained is 56nm.

Embodiment 2

Get 600gNa ₂wO ₄5H ₂o is dissolved in 2L distilled water, adds 78mL ethyl orthosilicate; 180g hydrochloric acid is configured to solution, slowly drops in above-mentioned solution, room temperature lower magnetic force stirs 30min; Stir and be placed in the autoclave of inner liner polytetrafluoroethylene, baking oven reactor being put into 100 DEG C reacts 20h; Be cooled to room temperature after reaction, filter and use distilled water, absolute ethyl alcohol cyclic washing sediment; Gained precipitation puts into 60 DEG C of dry 9h of baking oven, then puts into the Muffle furnace calcination 3h of 450 DEG C; Then powder is placed in plasma reaction chamber, take operating voltage as 75v, operating current is the electric arc ionization argon gas that the condition of 600A produces, and plasma maintains about 1300 DEG C to tungstic acid and silica powder heating-up temperature, and obtained silicon tungsten powder average grain diameter of mixing is 43nm.

Embodiment 3

Get 600gNa ₂wO ₄5H ₂o is dissolved in 2L distilled water, adds 90mL ethyl orthosilicate; 300g hydrochloric acid is configured to solution, slowly drops in above-mentioned solution, room temperature lower magnetic force stirs 30min; Stir and be placed in the autoclave of inner liner polytetrafluoroethylene, baking oven reactor being put into 120 DEG C reacts 20h; Be cooled to room temperature after reaction, filter and use distilled water, absolute ethyl alcohol cyclic washing sediment; Gained precipitation puts into 70 DEG C of dry 8h of baking oven, then puts into the Muffle furnace calcination 2h of 500 DEG C; Then powder is placed in plasma reaction chamber, take operating voltage as 90v, operating current is the electric arc ionization argon gas that the condition of 700A produces, and plasma maintains about 1800 DEG C to tungstic acid and silica powder heating-up temperature, and the silicon tungsten powder average grain diameter of mixing of acquisition is 30nm.

Above-mentioned embodiment is used for illustrative purposes only, and be not limitation of the present invention, the those of ordinary skill of relevant technical field, without departing from the spirit and scope of the present invention, can also make various change and modification, therefore all equivalent technical schemes also should belong to category of the present invention.

Claims

1. mix a preparation technology for silicon tungsten powder, it comprises the following steps:

(2) drip hydrochloric acid solution again, magnetic agitation mixes;

(3) mixed solution is placed in autoclave and adds thermal response;

(5) sediment of oven dry is put into Muffle furnace calcination, obtain silica and tungstic acid powder;

(6) silica and tungstic acid powder are placed in plasma reaction chamber, in this reative cell, form high-temperature plasma by ionization inert gas, after silica and tungstic acid powder are heated by high-temperature plasma, be reduced into tungsten silica flour under reducing atmosphere.

2. technique according to claim 1, is characterized in that: described Na ₂wO ₄5H ₂o(g), the ratio of ethyl orthosilicate (mL), hydrochloric acid (g) is 1:(0.1-0.15): (0.1-0.5).

3. technique according to claim 1, is characterized in that: the heating-up temperature of reactor is 80 DEG C--120 DEG C, the reaction time is 20h-24h.

4. technique according to claim 1, is characterized in that: adopt distilled water and absolute ethyl alcohol cyclic washing during washing.

5. technique according to claim 1, is characterized in that: adopt 50 DEG C during oven dry--dry 8h-10h for 70 DEG C.

6. technique according to claim 1, is characterized in that: in Muffle furnace, adopt 400 DEG C--the temperature calcination 2h-4h of 500 DEG C.

7. technique according to claim 1, is characterized in that: plasma reaction is indoor is plasma working gas with argon gas, and hydrogen is reducing atmosphere; With silica and tungstic acid powder for positive pole, plasma gun is negative pole, the electric arc ionization inert gas produced between a positive electrode and a negative electrode after energising, thus forms high-temperature plasma to silica and the heating of tungstic acid powder.

8. technique according to claim 7, is characterized in that: operating voltage during energising is 60v--90v, and operating current is 400A--700A.

9. technique according to claim 7, is characterized in that: be 1000 DEG C to the heating-up temperature of silica and tungstic acid powder--1800 DEG C.