阅读说明：本技术 一种人造金刚石分离提纯方法 (Artificial diamond separation and purification method ) 是由 荣广华 于 2020-06-28 设计创作，主要内容包括：本发明公开了一种人造金刚石分离提纯方法,通过利用金刚石与石墨化学性质的差异实现的,通过搅拌、静置、沉降,多次循环重复,将氧化石墨悬浮液与沉淀的金刚石颗粒分离,并经过干燥处理后,可分别获得氧化石墨和高纯度的人造金刚石,该分离提纯方法避免了资源的浪费,同时减少废气的产生、减少废液的污染,是一种绿色、环保的方法；该分离提纯方法,通过使用分离提纯设备进行人造金刚石的分离提纯；该分离提纯设备自动完成了混合物C与稀盐酸重复混合、离心过程,得到沉淀物,并自动完成了沉淀物的洗涤、搅拌、离心过程,将金刚石与石墨悬浮液分离开,提高了生产效率,同时分离提纯效果好,得到的人造金刚石与石墨品质高。(The invention discloses a method for separating and purifying artificial diamond, which is realized by utilizing the difference of the chemical properties of diamond and graphite, separates graphite oxide suspension from precipitated diamond particles through stirring, standing, settling and repeated circulation for many times, and can respectively obtain graphite oxide and high-purity artificial diamond after drying treatment; the separation and purification method is characterized in that the separation and purification of the artificial diamond are carried out by using separation and purification equipment; the separation and purification equipment automatically completes the repeated mixing and centrifuging processes of the mixture C and the dilute hydrochloric acid to obtain the precipitate, automatically completes the washing, stirring and centrifuging processes of the precipitate, separates the diamond from the graphite suspension, improves the production efficiency, has good separation and purification effects, and obtains the artificial diamond and the graphite with high quality.)

1. A method for separating and purifying artificial diamond is characterized by comprising the following steps:

the method comprises the following steps: adding the artificial diamond concentrate into concentrated sulfuric acid at the temperature of 0-10 ℃, and stirring for 0.5-1 h to obtain a mixture A1; adding nitrate into the mixture A1 at 0-10 ℃, and stirring for 0.5-1 h to obtain a mixture A2; adding potassium permanganate into the mixture A2 at the temperature of 0-10 ℃, and stirring for 1-3 hours to obtain a mixture A;

step two: stirring the mixture A at the temperature of 20-40 ℃ for 0.5-2.5 h, cooling to 0-10 ℃, adding deionized water, heating to 75-95 ℃, stirring for 0.5-1.5 h, and obtaining a mixture B;

step three: adding deionized water and hydrogen peroxide into the mixture B under the conditions of room temperature and stirring, and mixing to obtain a mixture C;

step four: adding the mixture C into a centrifugal cylinder (117) of separation and purification equipment, screwing a sealing cover (108), connecting a liquid inlet pipe (109) with an adapter (110), filling dilute hydrochloric acid into a liquid storage tank (113), conveying the dilute hydrochloric acid in the liquid storage tank (113) into the centrifugal cylinder (117) and an inner cavity of a separation and purification bin (102) through the operation of a second conveying pump (112), driving the centrifugal cylinder (117) and a stirring shaft (119) to rotate through the operation of a driving motor (106), uniformly mixing the mixture C and the dilute hydrochloric acid, performing centrifugal separation to obtain a precipitate D1, adding the dilute hydrochloric acid into the precipitate D1, performing centrifugal separation to obtain a precipitate D2 after uniform mixing, adding the dilute hydrochloric acid into the precipitate D2, repeatedly washing and performing centrifugal separation to obtain a precipitate D3, replacing the dilute hydrochloric acid in the liquid storage tank (113) with deionized water, adding the deionized water into the precipitate D3, performing centrifugal separation after uniform mixing to obtain a precipitate D4, adding deionized water into the precipitate D4, repeatedly washing and centrifugally separating until the pH value of the separated liquid is 6.0-7.0, and obtaining a precipitate as a solid mixture D;

step five: adding the solid mixture D into deionized water, stirring and dispersing, standing, separating to obtain precipitate E1 and separation liquid, adding precipitate E1 into deionized water, stirring and dispersing, standing, separating to obtain precipitate E2 and separation liquid, repeating the operations of adding deionized water, dispersing, standing and separating on the precipitate E2 until the separation liquid is clear, and obtaining precipitate E, wherein the precipitate E is artificial diamond particles; and combining the poured separation liquid, and drying to obtain the graphite oxide.

2. The method for separating and purifying the artificial diamond according to claim 1, wherein the process for preparing the artificial diamond concentrate comprises the following steps:

crushing the synthetic blocks from which the catalyst metal is removed through electrolysis, and performing primary separation by adopting a table concentrator method to obtain an artificial diamond concentrate; wherein, the synthetic block is a synthetic block of artificial diamond synthesized by a high-temperature high-pressure metal powder catalyst method; wherein, the table concentrator method is to carry out primary separation according to the density difference of diamond and graphite; wherein the mass content of diamond in the artificial diamond concentrate is about 40%.

3. The method for separating and purifying the artificial diamond according to claim 1, wherein the adding amount of the concentrated sulfuric acid, the nitrate and the potassium permanganate in the step one is as follows: adding 45-55L of concentrated sulfuric acid, 0.8-1.5 kg of nitrate and 5-8 kg of potassium permanganate into every 2kg of artificial diamond concentrate; wherein the mass concentration of the concentrated sulfuric acid is 95-98%, and the nitrate is sodium nitrate; the stirring speed in the step is 300-600 rpm.

4. The method for separating and purifying synthetic diamond according to claim 1, wherein in the second step, the deionized water is added in an amount of: 50-100L of deionized water is correspondingly added into every 2kg of artificial diamond concentrate; the stirring speed in this step is 300-600 rpm.

5. The method for separating and purifying synthetic diamond according to claim 1, wherein the deionized water is added in the third step in an amount of: adding 150-250L of deionized water correspondingly for every 2kg of artificial diamond concentrate; the adding amount of the hydrogen peroxide is as follows: 5-10L of hydrogen peroxide is correspondingly added into every 2kg of artificial diamond concentrate, wherein the volume fraction of the hydrogen peroxide is 30%.

6. The method for separating and purifying the artificial diamond according to claim 1, wherein the solid mixture D in the fourth step is a mixture of diamond and graphite oxide, wherein the mass concentration of the dilute hydrochloric acid is 4-6%;

wherein, when diluted hydrochloric acid is used for washing, the rotating speed of centrifugal separation is 3000-6000 rpm, and the time of each centrifugal separation is 6-10 min; when deionized water is used for washing, the rotating speed of centrifugal separation is 8000-11000 rpm, and the time of each centrifugal separation is 10-20 min;

wherein the addition amount of the dilute hydrochloric acid and the deionized water is as follows: and adding 50-80L of dilute hydrochloric acid or deionized water every 2kg of the artificial diamond concentrate during centrifugation.

7. The method for separating and purifying synthetic diamond according to claim 1, wherein the amount of deionized water added in the fifth step is: the amount of deionized water added to every 2kg of artificial diamond concentrate is 50-60L, the standing time is 1-5 min, and the drying temperature is 55-65 ℃.

8. The method for separating and purifying synthetic diamond according to claim 1, wherein the separation and purification equipment in the fourth step operates as follows:

the method comprises the following steps: adding the mixture C into a centrifugal cylinder (117), screwing a sealing cover (108), closing a turnover door (107), connecting a liquid inlet pipe (109) with an adapter (110), and filling dilute hydrochloric acid into a liquid storage tank (113);

step two: starting a second delivery pump (112), wherein the second delivery pump (112) is operated to deliver the dilute hydrochloric acid in the liquid storage tank (113) to the centrifuge cylinder (117) and the inner cavity of the separation and purification bin (102) through a liquid delivery pipe (111) and a liquid inlet pipe (109);

step three: starting a driving motor (106), wherein the driving motor (106) runs to drive a linkage shaft (115) to rotate through a driving belt pulley (114) and a driven belt pulley (116), so that a centrifugal cylinder (117) and a stirring shaft (119) are driven to rotate, and the mixture C and the dilute hydrochloric acid are fully mixed;

step four: releasing dilute hydrochloric acid in the inner cavity of the separation and purification bin (102) into a liquid receiving hopper (103), centrifugally separating the dilute hydrochloric acid in the mixture C by a rotating centrifugal cylinder (117), and conveying the dilute hydrochloric acid into a liquid discharge pipe (104) of a first conveying pump (105) through the liquid receiving hopper (103) to a waste liquid barrel;

step five: repeating the step one to the step four times to obtain a precipitate D3, replacing the dilute hydrochloric acid in the liquid storage tank (113) with deionized water, repeating the step one to the step four times for a plurality of times until the pH value of the separated liquid detected from the detection port (120) is 6.0-7.0, and connecting a liquid discharge pipe (104) of the first conveying pump (105) with a liquid storage barrel;

step six: repeating the steps one to four for a plurality of times until the separated liquid is clarified through observation from the detection port (120), stopping operating the separation and purification equipment, taking out the precipitate in the centrifugal cylinder (117) to obtain artificial diamond particles, and drying the separated liquid in the liquid storage barrel to obtain the graphite oxide.

Technical Field

The invention relates to the field of artificial diamond, in particular to a method for separating and purifying artificial diamond.

Background

The diamond has the highest hardness and thermal conductivity in the nature, good wear resistance, chemical stability and the like, and has wide application prospects in the fields of mechanics, thermal, electronics, optics and the like. As a superhard material, diamond abrasive materials and products are widely applied to the aspects of automobile, machinery, electronics, aviation, optical instrument processing and the like, and the requirement on the purity of diamond is higher and higher along with the expansion of application.

The application number is CN100528748C, which discloses a purification method of high-purity diamond micropowder, the diamond micropowder raw material synthesized by static pressure or detonation is put into a mixed acid of nitric acid, hydrofluoric acid and perchloric acid or a mixed acid of perchloric acid and hydrofluoric acid, heated until the acid is boiled and kept for 0.5-6 hours to dissolve various impurities adsorbed on the surface of the diamond micropowder, and then the residual acid and various impurities are removed by rinsing with high-purity water, and the diamond micropowder is obtained by drying; the following disadvantages still exist: (1) the high-temperature strong acid oxidation method not only needs to consume a large amount of acid, but also generates a large amount of toxic gases such as sulfuric acid smoke, sulfide, nitric oxide and the like, which poison human health, and the discharged waste acid can seriously pollute soil and water; (2) in the existing purification method, solid-liquid separation is carried out by using a natural sedimentation mode, the diamond and graphite suspension cannot be effectively separated, the separation and purification effect is not good enough, and the obtained artificial diamond has low quality and purity.

Disclosure of Invention

In order to overcome the technical problems, the invention aims to provide a method for separating and purifying artificial diamond, which comprises the following steps: (1) by exploiting the difference in diamond and graphite chemistry, namely: the method has the advantages that diamond does not react with concentrated sulfuric acid at low temperature and is not oxidized by strong oxidant, while graphite is easily oxidized by some strong oxidant, so that graphite forms uniform suspension, the graphite can be stably dispersed in deionized water, diamond particles are not changed, the graphite can be separated from the precipitated diamond particles through stirring, standing and settling, and repeated circulation, and the graphite oxide suspension and the precipitated diamond particles can be respectively obtained after drying treatment, thereby solving the problems that the existing diamond separation method can generate a large amount of toxic gas, poison human health, and the discharged waste acid can seriously pollute soil and water; (2) the separation and purification of the artificial diamond are carried out by using separation and purification equipment, the mixture C is added into a centrifugal cylinder, a liquid storage tank is filled with dilute hydrochloric acid, the dilute hydrochloric acid in the liquid storage tank is conveyed into the centrifugal cylinder and an inner cavity of a separation and purification bin by the operation of a second conveying pump, a driving pulley and a driven pulley are used for driving a linkage shaft to rotate by the operation of a driving motor, so that the centrifugal cylinder and a stirring shaft are driven to rotate, the mixture C and the dilute hydrochloric acid are fully mixed, the dilute hydrochloric acid in the inner cavity of the separation and purification bin is discharged, the dilute hydrochloric acid in the liquid storage tank is replaced by deionized water and is repeatedly mixed for a plurality of times until the clarification of the separation liquid is observed from a detection port, the precipitate in the centrifugal cylinder is taken out, the artificial diamond particles are obtained, the separation liquid in the liquid storage tank is dried to obtain graphite oxide, and the, the separation and purification effect is not good enough, and the obtained artificial diamond has low quality and purity.

The purpose of the invention can be realized by the following technical scheme:

a method for separating and purifying artificial diamond comprises the following steps:

the method comprises the following steps: adding the artificial diamond concentrate into concentrated sulfuric acid at the temperature of 0-10 ℃, and stirring for 0.5-1 h to obtain a mixture A1; adding nitrate into the mixture A1 at 0-10 ℃, and stirring for 0.5-1 h to obtain a mixture A2; adding potassium permanganate into the mixture A2 at the temperature of 0-10 ℃, and stirring for 1-3 hours to obtain a mixture A;

step two: stirring the mixture A at the temperature of 20-40 ℃ for 0.5-2.5 h, cooling to 0-10 ℃, adding deionized water, heating to 75-95 ℃, stirring for 0.5-1.5 h, and obtaining a mixture B;

step three: adding deionized water and hydrogen peroxide into the mixture B under the conditions of room temperature and stirring, and mixing to obtain a mixture C;

step four: adding the mixture C into a centrifuge tube of a separation and purification device, screwing a sealing cover, connecting a liquid inlet pipe with an adapter, filling dilute hydrochloric acid into a liquid storage tank, the second delivery pump is operated to deliver the dilute hydrochloric acid in the liquid storage tank to the centrifuge bowl and the inner cavity of the separation and purification bin, driving a centrifugal cylinder and a stirring shaft to rotate by the operation of a driving motor, uniformly mixing the mixture C and dilute hydrochloric acid, performing centrifugal separation to obtain a precipitate D1, adding dilute hydrochloric acid into the precipitate D1, performing centrifugal separation to obtain a precipitate D2 after uniform mixing, adding dilute hydrochloric acid into the precipitate D2, repeatedly washing and performing centrifugal separation, obtaining a precipitate D3, replacing dilute hydrochloric acid in a liquid storage tank with deionized water, adding deionized water into the precipitate D3, uniformly mixing, performing centrifugal separation to obtain a precipitate D4, adding deionized water into the precipitate D4, repeatedly washing and performing centrifugal separation until the pH value of a separation liquid is 6.0-7.0, and obtaining a precipitate as a solid mixture D;

step five: adding the solid mixture D into deionized water, stirring and dispersing, standing, separating to obtain precipitate E1 and separation liquid, adding precipitate E1 into deionized water, stirring and dispersing, standing, separating to obtain precipitate E2 and separation liquid, repeating the operations of adding deionized water, dispersing, standing and separating on the precipitate E2 until the separation liquid is clear, and obtaining precipitate E, wherein the precipitate E is artificial diamond particles; and combining the poured separation liquid, and drying to obtain the graphite oxide.

As a further scheme of the invention: the preparation process of the artificial diamond concentrate comprises the following steps:

crushing the synthetic blocks from which the catalyst metal is removed through electrolysis, and performing primary separation by adopting a table concentrator method to obtain an artificial diamond concentrate; wherein, the synthetic block is a synthetic block of artificial diamond synthesized by a high-temperature high-pressure metal powder catalyst method; wherein, the table concentrator method is to carry out primary separation according to the density difference of diamond and graphite; wherein the mass content of diamond in the artificial diamond concentrate is about 40%.

As a further scheme of the invention: the adding amount of concentrated sulfuric acid, nitrate and potassium permanganate in the step one is as follows: adding 45-55L of concentrated sulfuric acid, 0.8-1.5 kg of nitrate and 5-8 kg of potassium permanganate into every 2kg of artificial diamond concentrate; wherein the mass concentration of the concentrated sulfuric acid is 95-98%, and the nitrate is sodium nitrate; the stirring speed in the step is 300-600 rpm.

As a further scheme of the invention: in the second step, the addition amount of the deionized water is as follows: 50-100L of deionized water is correspondingly added into every 2kg of artificial diamond concentrate; the stirring speed in this step is 300-600 rpm.

As a further scheme of the invention: the addition amount of the deionized water in the third step is as follows: adding 150-250L of deionized water correspondingly for every 2kg of artificial diamond concentrate; the adding amount of the hydrogen peroxide is as follows: 5-10L of hydrogen peroxide is correspondingly added into every 2kg of artificial diamond concentrate, wherein the volume fraction of the hydrogen peroxide is 30%.

As a further scheme of the invention: the solid mixture D in the fourth step is a mixture of diamond and graphite oxide, wherein the mass concentration of the dilute hydrochloric acid is 4-6%;

wherein, when diluted hydrochloric acid is used for washing, the rotating speed of centrifugal separation is 3000-6000 rpm, and the time of each centrifugal separation is 6-10 min; when deionized water is used for washing, the rotating speed of centrifugal separation is 8000-11000 rpm, and the time of each centrifugal separation is 10-20 min;

wherein the addition amount of the dilute hydrochloric acid and the deionized water is as follows: and adding 50-80L of dilute hydrochloric acid or deionized water every 2kg of the artificial diamond concentrate during centrifugation.

As a further scheme of the invention: the addition amount of the deionized water in the step five is as follows: the amount of deionized water added to every 2kg of artificial diamond concentrate is 50-60L, the standing time is 1-5 min, and the drying temperature is 55-65 ℃.

As a further scheme of the invention: the working process of the separation and purification equipment in the fourth step is as follows:

the method comprises the following steps: adding the mixture C into a centrifugal cylinder, screwing a sealing cover, closing a turnover door, connecting a liquid inlet pipe with an adapter, and filling dilute hydrochloric acid into a liquid storage tank;

step two: starting a second conveying pump, wherein the second conveying pump is operated to convey the dilute hydrochloric acid in the liquid storage tank to the centrifugal cylinder and the inner cavity of the separation and purification bin through a liquid conveying pipe and a liquid inlet pipe;

step three: starting a driving motor, wherein the driving motor runs to drive a linkage shaft to rotate through a driving belt pulley and a driven belt pulley so as to drive a centrifugal cylinder and a stirring shaft to rotate, and thus, the mixture C and the dilute hydrochloric acid are fully mixed;

step four: releasing dilute hydrochloric acid in the inner cavity of the separation and purification bin into a liquid receiving hopper, centrifuging the dilute hydrochloric acid in the mixture C by using a rotating centrifugal cylinder, and conveying the dilute hydrochloric acid into a liquid discharge pipe of a first conveying pump through the liquid receiving hopper and into a waste liquid barrel;

step five: repeating the step one to the step four times to obtain a precipitate D3, replacing the dilute hydrochloric acid in the liquid storage tank with deionized water, repeating the step one to the step four times for a plurality of times until the pH value of the separated liquid is detected to be 6.0-7.0 from the detection port, and connecting a liquid discharge pipe of the first conveying pump with a liquid storage barrel;

step six: and repeating the steps one to four for a plurality of times until the separated liquid is clarified through observation from the detection port, stopping operating the separation and purification equipment, taking out the precipitate in the centrifugal cylinder to obtain artificial diamond particles, and drying the separated liquid in the liquid storage barrel to obtain the graphite oxide.

The invention has the beneficial effects that:

(1) the invention relates to a method for separating and purifying artificial diamond, which is realized by utilizing the difference of chemical properties of diamond and graphite, and comprises the following steps: the method comprises the following steps of (1) at a low temperature, enabling the diamond not to react with concentrated sulfuric acid and not to be oxidized by a strong oxidant, enabling graphite to be easily oxidized by some strong oxidants to form uniform suspension, enabling the suspension to be stably dispersed in deionized water, enabling diamond particles not to change, separating the graphite oxide suspension from the precipitated diamond particles through stirring, standing, settling and repeated circulation for many times, and obtaining graphite oxide and high-purity artificial diamond after drying treatment;

the separation and purification method overcomes the defects of high consumption and high pollution of the traditional artificial diamond concentrate graphite removal process, simultaneously fully utilizes the waste graphite, converts the graphite into graphite oxide with wide application prospect, can be used for preparing graphene, and is not converted into carbon dioxide emission by a high-temperature heating method in the traditional method, so that waste is changed into valuable, the waste of resources is avoided, the generation of waste gas is reduced, and the pollution of waste liquid is reduced, thereby being a green and environment-friendly method;

taking out the precipitate, performing suction filtration, drying in a 60 ℃ forced air drying oven, combining the poured separation liquid, drying in a 65 ℃ forced air drying oven, respectively weighing the mass, calculating the recovery rate, and calculating the result: the recovery rate of the diamond is 38.3-39.1%, and the yield of the graphite is 10.6-12.2%.

(2) The invention relates to a method for separating and purifying artificial diamond, which separates and purifies the artificial diamond by using separation and purification equipment, fills dilute hydrochloric acid into a liquid storage tank after a mixture C is added into a centrifugal cylinder, the second delivery pump is operated to deliver the dilute hydrochloric acid in the liquid storage tank to the centrifuge bowl and the inner cavity of the separation and purification bin, the driving motor runs to drive the linkage shaft to rotate through the driving belt pulley and the driven belt pulley, driving the centrifugal cylinder and the stirring shaft to rotate, fully mixing the mixture C and the dilute hydrochloric acid, discharging the dilute hydrochloric acid in the inner cavity of the separation and purification bin, replacing the dilute hydrochloric acid in the liquid storage tank with deionized water, repeatedly mixing for a plurality of times until the separated liquid is observed from the detection port and clarified, taking out the precipitate in the centrifugal cylinder to obtain artificial diamond particles, and drying the separated liquid in the liquid storage tank to obtain graphite oxide; the separation and purification equipment automatically completes the repeated mixing and centrifuging processes of the mixture C and the dilute hydrochloric acid to obtain precipitates, conveys deionized water to automatically complete the washing, stirring and centrifuging processes of the precipitates, separates diamond from graphite suspension, has high automation, improves the production efficiency, has good separation and purification effects, and obtains the artificial diamond and the graphite with high quality.

Drawings

The invention will be further described with reference to the accompanying drawings.

FIG. 1 is a schematic view of the structure of a separation and purification apparatus according to the present invention;

FIG. 2 is a side view of the separation and purification apparatus of the present invention;

FIG. 3 is a front view of the separation and purification apparatus of the present invention;

FIG. 4 is a schematic view of the internal structure of the separation and purification unit according to the present invention;

FIG. 5 is a schematic view of the internal structure of the centrifugal cylinder of the present invention;

FIG. 6 is a plan view of the liquid receiving hopper of the present invention.

In the figure: 101. a mounting frame; 102. a separation and purification bin; 103. a liquid receiving hopper; 104. a liquid discharge pipe; 105. a first delivery pump; 106. a drive motor; 107. turning over the door; 108. a sealing cover; 109. a liquid inlet pipe; 110. an adapter; 111. a transfusion tube; 112. a second delivery pump; 113. a liquid storage tank; 114. a drive pulley; 115. a linkage shaft; 116. a driven pulley; 117. a centrifugal cylinder; 118. a weep hole; 119. a stirring shaft; 120. a detection port; 121. and (7) mounting the plate.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to 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.