CN102530967A

CN102530967A - Process for preparing white carbon black by utilizing waste silicon molybdenum rod

Info

Publication number: CN102530967A
Application number: CN2012100024115A
Authority: CN
Inventors: 冯培忠; 王晓虹; 徐越; 沈承金; 陶雪钰; 刘炯天
Original assignee: China University of Mining and Technology CUMT
Current assignee: China University of Mining and Technology CUMT
Priority date: 2012-01-06
Filing date: 2012-01-06
Publication date: 2012-07-04
Anticipated expiration: 2032-01-06
Also published as: CN102530967B

Abstract

The invention provides a process for preparing white carbon black by utilizing a waste silicon molybdenum rod and belongs to the technical field of waste reclamation. The method comprises the following steps: carrying out crashing and ball milling on waste molybdenum disilicide to obtain powder with the grain size of 1-20 microns, and then roasting the powder in an electric furnace at the temperature of 450-550DEG C for 3-8 hours, so as to oxidize the waste molybdenum disilicide into MoO3 and SiO2; carrying out chemical reaction on the oxidized powder and NaOH to form sodium molybdate and sodium silicate; filtering to remove undissolved impurities; dropwise adding nitric acid into a filtrate so as to regulate the pH to 8.5-9.0; standing for 20-48 hours so as to precipitate out silica gel; filtering to obtain a white gelatinous precipitate, and baking, roasting and dehydrating the white gelatinous precipitate; and washing out residual impurities with de-ionized water, thus obtaining a white carbon black product. The process provided by the invention has the following advantages: the silicon in the waste silicon molybdenum rod can be reused to prepare the white carbon black product, and thus the cyclic utilization of silicon resources is realized; and the targeting performance is strong, the process is simple and convenient, equipment is simple, resources are saved, and the applications are wide.

Description

A kind of technology of utilizing waste and old Si-Mo rod to prepare WHITE CARBON BLACK

Technical field

The invention belongs to the waste reclaimation technical field, especially relate to a kind of technology of utilizing waste and old Si-Mo rod to prepare WHITE CARBON BLACK.

Background technology

Molybdenum disilicide (MoSi ₂) with its high melt point (2030 ℃); Fabulous high-temperature oxidation resistance (in air, can use 1850 ℃); Moderate density (6.24gcm ^-3); Lower thermal expansivity (8.1 * 10 ^-6K ^-1); Good electric heating conductivity (resistivity 21.5 * 10 ^-6Ω cm, thermal conductivity 50.0Wm ^-1K ^-1); Can carry out electrical discharge machining (EDM); The high-temperature structural material that has potentiality that characteristic such as pollution-free and good environment friendly and being considered to occurs after Ni, Ti base superalloy and structural ceramics, its correlative study is operated in and has caused showing great attention to of institute of United States Navy and Los Alamos National Laboratory the eighties in 20th century.Successively hold twice High Temperature Structural Silicides international conference the nineties in 20th century, caused the upsurge of global research molybdenum disilicide thus.

Because MoSi ₂There is room temperature poor toughness (the about 3.0MPam of room temperature fracture toughness ^1/2), hot strength low (＞1000 ℃ of easy creeps), and low temperature efflorescence pestilence (～500 ℃) three big defectives, thus limited its application as high-temperature structural material.

MoSi ₂Maximum at present application is as the high temperature Heating element, is also referred to as Si-Mo rod.Nineteen forty-seven Sweden Kanthal company begins the research of Si-Mo rod; Kanthal in 1956 have obtained the patent of invention of first Si-Mo rod of the whole world; The seventies in 20th century; The FSU has set up Si-Mo rod manufacturing enterprise on the basis of self propagating high temperature synthetic technology, the eighties in 20th century, China began the production of Si-Mo rod on Zhengzhou, Henan and Tianjin and other places.Whole world Si-Mo rod manufacturing enterprise mainly concentrates on Sweden, the U.S., Korea S, China and Japanese, and output in domestic was estimated as about 300 tons in 2010.This means that following China will have 300 tons of waste and old Si-Mo rods to need to handle every year, up to the present, if about effectively utilizing waste and old molybdenum silicide also to lack relevant report.

From MoSi ₂Chemical formula can find out MoSi ₂Mainly be made up of Mo and Si, wherein Mo content is 63%, and Si content is 37%.Mo is a kind of noble metal, in defence and military and national economy, occupies an important strategic position.Equally, Si also is a kind of important semiconductor alloy, has purposes very widely at electron device and field of solar energy, the fast development of global solar industry especially in recent years, and supply falls short of demand to make polysilicon, and its price is up to hundreds of dollars.And with SiO ₂The WHITE CARBON BLACK for preparing for the basis has a series of meliority.

WHITE CARBON BLACK can be widely used in many fields.For example Nano carbon white has tridimensional network, has huge specific surface area, shows great activity, not only can increase the intensity and the smooth finish of coating, and has improved the suspension of pigment, keeps the color of coating not fade for a long time.In building inside and outside wall coating,, can obviously improve jar effect of opening of coating if add Nano carbon white.Nano carbon white also can with the pigment dyestuff adapted, obtain photochromic coating.

Therefore, the present invention is based on the present situation that a large amount of waste and old Si-Mo rods go out of use or leave unused, develop the technology of the waste and old Si-Mo rod of a kind of recycling; Utilize waste and old molybdenum silicide to prepare WHITE CARBON BLACK; Make the silicon in the waste and old Si-Mo rod obtain recycling, realize resource-constrained, unlimited strategy circulates.

Summary of the invention

The object of the present invention is to provide a kind of technology of utilizing waste and old Si-Mo rod to prepare WHITE CARBON BLACK, solved the recycling problem of waste and old Si-Mo rod, and technology is simple, effective, save resource.

Process step of the present invention is following:

(1) waste and old molybdenum disilicide is dropped into the jaw crushing crusher machine, the material that fragmentation is obtained changes ball mill inside over to, and ball milling is 10～48 hours in ball mill, is ground into and is of a size of 1～20 micron powder;

(2) change the powder that obtains behind the ball milling over to porcelain boat, place chamber type electric resistance furnace in 450～550 ℃, roasting 3～8 hours, waste and old molybdenum disilicide is oxidized to MoO ₃And SiO ₂Powder.

(3) with the MoO of step (2) ₃And SiO ₂Powder adds in the NaOH solution of 1.0～1.6 times of theoretical reacting weights, makes MoO ₃And SiO ₂Chemical reaction takes place and forms Sodium orthomolybdate and water glass in powder and NaOH, filters to remove not dissolve impurity.

(4) in filtrating, drip nitric acid, transferring pH is 8.5～9.0, leaves standstill 20～48h, and the silica gel deposition is separated out, and filters silica gel with the suction filtration device, obtains white gelatinous precipitate; With white gelatinous precipitate oven dry, moisture is sloughed in roasting, uses deionized water flush away residual impurity again, obtains the WHITE CARBON BLACK product after the oven dry once more.

Compared with present technology, the invention enables the silicon in the waste and old Si-Mo rod to obtain utilizing again again, prepared submicron order WHITE CARBON BLACK product, realized the recycle of silicon resource.And, with strong points, technology is easy, equipment is simple, economize on resources, and has purposes widely.

Description of drawings

Fig. 1 is the X ray diffracting spectrum that the present invention obtains product.Prepare WHITE CARBON BLACK by scheming to find out.

Fig. 2 is the SEM pattern of the WHITE CARBON BLACK for preparing of the present invention.

Embodiment

Example 1. was crushed into 1 micron powder in 48 hours with waste and old molybdenum disilicide ball milling in ball mill, placed chamber type electric resistance furnace in 450 ℃ of roastings 8 hours then, the powder after the roasting was added in the NaOH solution of 1.0 times of theoretical reacting weights; Make powder and NaOH behind the roasting oxidation that chemical reaction formation Sodium orthomolybdate and water glass take place, filter to remove and dissolve impurity, in filtrating, drip nitric acid; Transferring pH is 8.5; Leave standstill 20h, the silica gel deposition is separated out, filter and obtain white gelatinous precipitate; With gelatinous precipitate oven dry, roasting, cleaning, obtain purified WHITE CARBON BLACK product after the oven dry once more.

Example 2. was crushed into 5 microns powder in 40 hours with waste and old molybdenum disilicide ball milling in ball mill, placed chamber type electric resistance furnace in 480 ℃ of roastings 7 hours then, the powder after the roasting was added in the NaOH solution of 1.2 times of theoretical reacting weights; Make powder and NaOH behind the roasting oxidation that chemical reaction formation Sodium orthomolybdate and water glass take place, filter to remove and dissolve impurity, in filtrating, drip nitric acid; Transferring pH is 8.7; Leave standstill 25h, the silica gel deposition is separated out, filter and obtain white gelatinous precipitate; With gelatinous precipitate oven dry, roasting, cleaning, obtain purified WHITE CARBON BLACK product after the oven dry once more.

Example 3. was crushed into 10 microns powder in 30 hours with waste and old molybdenum disilicide ball milling in ball mill, placed chamber type electric resistance furnace in 500 ℃ of roastings 3 hours then, the powder after the roasting was added in the NaOH solution of 1.4 times of theoretical reacting weights; Make powder and NaOH behind the roasting oxidation that chemical reaction formation Sodium orthomolybdate and water glass take place, filter to remove and dissolve impurity, in filtrating, drip nitric acid; Transferring pH is 8.8; Leave standstill 35h, the silica gel deposition is separated out, filter and obtain white gelatinous precipitate; With gelatinous precipitate oven dry, roasting, cleaning, obtain purified WHITE CARBON BLACK product after the oven dry once more.

Example 4. was crushed into 15 microns powder in 20 hours with waste and old molybdenum disilicide ball milling in ball mill, placed chamber type electric resistance furnace in 520 ℃ of roastings 5 hours then, the powder after the roasting was added in the NaOH solution of 1.6 times of theoretical reacting weights; Make powder and NaOH behind the roasting oxidation that chemical reaction formation Sodium orthomolybdate and water glass take place, filter to remove and dissolve impurity, in filtrating, drip nitric acid; Transferring pH is 9.0; Leave standstill 40h, the silica gel deposition is separated out, filter and obtain white gelatinous precipitate; With gelatinous precipitate oven dry, roasting, cleaning, obtain purified WHITE CARBON BLACK product after the oven dry once more.

Example 5. was crushed into 20 microns powder in 10 hours with waste and old molybdenum disilicide ball milling in ball mill, placed chamber type electric resistance furnace in 550 ℃ of roastings 6 hours then, the powder after the roasting was added in the NaOH solution of 1.6 times of theoretical reacting weights; Make powder and NaOH behind the roasting oxidation that chemical reaction formation Sodium orthomolybdate and water glass take place, filter to remove and dissolve impurity, in filtrating, drip nitric acid; Transferring pH is 8.9; Leave standstill 48h, the silica gel deposition is separated out, filtering to white gelatinous precipitate; With gelatinous precipitate oven dry, roasting, cleaning, obtain purified WHITE CARBON BLACK product after the oven dry once more.

Claims

1. technology of utilizing waste and old Si-Mo rod to prepare WHITE CARBON BLACK is characterized in that process step is following:

(2) powder that obtains behind the ball milling is changed in the porcelain boat, place chamber type electric resistance furnace in 450～550 ℃, roasting 3～8 hours, waste and old molybdenum disilicide is oxidized to MoO ₃And SiO ₂Powder;

(3) with the MoO of step (2) ₃And SiO ₂Powder adds in the NaOH solution of 1.0～1.6 times of theoretical reacting weights, makes MoO ₃And SiO ₂Chemical reaction takes place and forms Sodium orthomolybdate and water glass in powder and NaOH, filters to remove not dissolve impurity;