CN1102821A - Method for changing colour of natural sapphire - Google Patents
Method for changing colour of natural sapphire Download PDFInfo
- Publication number
- CN1102821A CN1102821A CN 94104443 CN94104443A CN1102821A CN 1102821 A CN1102821 A CN 1102821A CN 94104443 CN94104443 CN 94104443 CN 94104443 A CN94104443 A CN 94104443A CN 1102821 A CN1102821 A CN 1102821A
- Authority
- CN
- China
- Prior art keywords
- thermal treatment
- hydrogen
- incubated
- step thermal
- sapphire
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Crystals, And After-Treatments Of Crystals (AREA)
Abstract
The said colour-modifying process is a two-step heat treatment one including the diffusion in an oxidation atmosphere and the annealing in a reduction atmosphere. Through the said process, natural sapphire is discolored and its transmissivity increased and will have the hue of cornflower blue. The said process can greatly increase the application and economic values of natural sapphire.
Description
The invention belongs to the modification of mineral crystal.Specifically, the invention belongs to crystalline thermal treatment, through handling it is changed colour mineral crystal.
A large amount of natural sapphires is contained on ground such as China East China, south China, but its color is dark excessively, and under the ordinary light irradiation, general thickness is then opaque greater than 3 millimeters sample, is black-and-blue or brown, so its ornamental value and economic worth are not high.Since nineteen ninety, have some, particularly occur successively about the colour generation mechanism of Shandong, Jiangsu natural sapphire and the reported literature of the research of changing colour about natural sapphire.The method of fading of traditional natural sapphire is the anneal under 1700 ℃, and this kind method requires high temperature, so inconvenience, and the jewel after handling almost loses blueness and gray.A kind of improved technology is to use the electrolysis fused salt to produce intensive oxidizing atmosphere, makes Fe in the sapphire
2+The ion partial oxidation, cause sapphire anti-reflection and present blueness (Wang Chuanfu et al., J.Geomol., 1992,23(4), 195-7).There is the shortcoming of equipment and operating aspect equally in this kind method, and the simple oxide treatment of this kind, will make the tonal variation of natural sapphire, and losing it original is the cornflowerblue tone that people liked, the sapphire after the processing is very easily discerned by naked eyes.
The method that the purpose of this invention is to provide a kind of thermal treatment natural sapphire, it is anti-reflection that it is faded, and have the cornflowerblue tone.This method is mainly diffusion under the oxidizing atmosphere and adds two step of annealed heat treatment process under the reducing atmosphere, comprises the optimized choice of thermal treatment roasting material and conditions such as atmosphere, temperature and soaking time.
Fig. 1 is the synoptic diagram of the step thermal treatment of second in the inventive method equipment therefor.Each several part is among Fig. 1: 1-burner hearth, 2-heating element, 3-crucible, 4-thermal insulation layer, 5-fire door, 6-mechanical pump, 7-tensimeter, 8-threeway, 9-gas meter, 10-reducing valve, 11-nitrogengas cylinder, 12-hydrogen cylinder, 13-drain tap.
Constituent analysis shows that the impurity content (particularly iron-holder) of above-mentioned natural sapphire (particularly Shandong saphire) is higher, and ferrous ion is to (Fe2+-Fe
2+) electron transition to cause centre wavelength be the broad absworption peak of 580 nanometers (nm, as follows), Fe2+-Ti
4+Electric charge between ion pair shifts also and forms light absorption at this wave band, and the superposition of number of mechanisms is the fundamental cause that causes the natural sapphire color depth. The absorption spectrum of undressed natural sapphire is seen the curve 1 of Fig. 2.
The first step thermal treatment of the present invention is the heat diffusion treatment under the oxidizing atmosphere.With particle diameter 10～100 microns pure corundum (Al
2O
3) powder is roasting material, in air or oxidizing atmosphere, is heated to 1100～1600 ℃, be incubated 4～100 hours, naturally cools to room temperature with stove after the outage.Through this processing, the impurity in the natural sapphire is reduced effectively by diffusion, and make Fe
2+The ion partial oxidation is Fe
3+Ion, thus the color of jewel is shoaled, and become transparent.Al as the roasting material
2O
3Powder is thin more, and it is good more then to spread with the effect of fading, but powder is thin more, requires its purity high more, otherwise will cause roasting material sintering and be difficult for peeling off from jewel.Preferred roasting material particle diameter is 50 microns, and get final product with analytical pure this moment.Preferred steady temperature is 1250 ℃, and the effect of fading this moment is the most obvious.For weight is the following natural sapphires of 5 grams, and preferred soaking time is 24 hours, and soaking time is too short, the DeGrain that then fades, and soaking time is long, effect there is no obvious improvement.The above-mentioned the first step thermal treatment natural sapphire is faded effectively, but its tone generally is pewter.On the absorption spectrum through the heat treated Shandong saphire of the first step, the absorption peak of 450 nanometers strengthens to some extent, sees the curve 2 of Fig. 2.
The second step thermal treatment of the present invention is the anneal under the reducing atmosphere, its objective is to make the natural sapphire that changes colour have the cornflowerblue tone.The second step thermal treatment can be with hydrogen, nitrogen mixed gas atmosphere (wherein the shared volume ratio of hydrogen is 5～10%) in open system, or in closed system with hydrogen or hydrogen, nitrogen mixed gas atmosphere (the burner hearth internal gas pressure is 120～150 kPas), be heated to 800～1200 ℃, be incubated 4～100 hours, then outage and naturally cool to room temperature with stove.Optimum condition is 140 kPas of air pressure, and 1000 ℃ of temperature are incubated 24 hours.The second step thermal treatment can make sapphire form the cornflowerblue tone, on the absorption spectrum (referring to Fig. 3) through the Shandong saphire after the two step thermal treatments of oxide-diffused and reduced anneal, the relative intensity of two absorption peaks of 450 nanometers and 580 nanometers and undressed Shandong saphire (referring to the curve 1 of Fig. 2) are approaching.
Use hydrogen to do the annealing thermal treatment of reducing atmosphere, the operation of should taking care, hydrogen, the oxygen of absolute prohibition when naked light is arranged mixes, and these all are that those skilled in the art are known.
In order to implement the second step thermal treatment (being the anneal under the reducing atmosphere) of the present invention, also can adopt other and Al
2O
3The hydrogenous material that does not react is made anneal for the roasting material.In when heating, these roasting material decompose and discharge hydrogen ion and enter sapphire.For example, will be immersed in the phenylformic acid of containing in the hard glass ware, be heated to 200～250 ℃, and be incubated 1～24 hour, can reach same purpose through the Shandong saphire after the oxide-diffused thermal treatment of the first step.In a word, according to spirit of the present invention and inventive concept, those skilled in the art can do many improvement, and these improve all within the scope of the invention.
The present invention's advantage is: equipment is simple, and technology is easy to grasp, and effect is splendid, the natural sapphire after handling through the present invention's method, and it is viewed and admired with economic worth and is improved largely.
Embodiment one: sample is guarded against the face blank for to make raw material with natural Shandong saphire through the non-standard facet type that cutting, corase grind form, and is of a size of 7.5 * 5.5 * 3.5 millimeters
3, weight is 0.24 gram, the sample before handling is translucent under high light, is black-and-blue.This sample is placed in the crucible, bury with the pure lapis amiridis of 400 orders on every side, the crucible of charge places in the common muffle furnace, is heated to 1250 ℃, is incubated after 24 hours, and outage also naturally cools to room temperature with stove.After the heat diffusion treatment under this kind oxidizing atmosphere (being the first step thermal treatment), sample becomes light blue, but its tone burnt hair.This sample is placed the pure hydrogen atmosphere (the burner hearth internal gas pressure is 140 kPas) of sealing to be heated to 800 ℃ again, be incubated after 12 hours, outage also naturally cools to room temperature with stove.Sample after the above-mentioned two step thermal treatments becomes sapphire transparent, shallow cornflowerblue color and guards against face through fine grinding, polishing processing.
Embodiment two: sample is for to make raw material with natural Shandong saphire, and the rectangular ear pendant blank through cutting, corase grind form is of a size of 11.5 * 5.6 * 2.4 millimeters
3, weight is 0.54 gram, the sample before the thermal treatment is transparent under high light, is mazarine.After this sample done the first step thermal treatment identical with example one, be immersed in again in the phenylformic acid of containing in the hard glass ware, be heated to 220 ℃, be incubated 4 hours, naturally cool to room temperature after the outage,, become transparent, the pure sapphire ear pendant attractive in appearance of tone again through fine grinding, polishing processing.
Comparative Examples: sample is guarded against face for to make raw material with natural Shandong saphire through the ellipsin body type that cutting, grinding, polishing process, and is of a size of 13.3 * 11.0 * 4.0 millimeters
3, weight is 1.2 grams, the sample before the thermal treatment is that brown is opaque.After this sample done but steady temperature similar to example one and be 1500 ℃ the first step thermal treatment, can be changed into transparently, but color is a pewter.
Claims (4)
1, a kind of method of thermal treatment natural sapphire, its feature are mainly the two step heat treatment processes that thermodiffusion (being the first step thermal treatment) under the oxidizing atmosphere adds the annealing (i.e. the second step thermal treatment) under the reducing atmosphere.
2, according to the method for claim 1, the first step thermal treatment use particle diameter is 10～100 microns pure corundum (Al
2O
3) powder is roasting material, is heated to 1100～1600 ℃ in air (or other oxidizing atmospheres), be incubated 4～100 hours, cut off the power supply then and naturally cool to room temperature with stove.
3, according to the method for claim 1, the second step thermal treatment in open system, adopts mobile hydrogen, nitrogen mixed gas atmosphere (wherein the shared volume ratio of hydrogen is 5～10%) or in closed system the pure hydrogen of employing or hydrogen, nitrogen mixed gas atmosphere (the burner hearth internal gas pressure is 120～150 kPas) carry out, steady temperature is 800～1200 ℃, be incubated 4～100 hours, then outage and naturally cool to room temperature with stove.
4, according to the method for claim 1, the second step thermal treatment also can take other Technologies to realize, it is characterized in that adopting not and Al
2O
3The hydrogenous material of reaction is roasting material, and these roasting material decompose when heating and can discharge hydrogen ion, for example is immersed in the phenylformic acid, is heated to 200～250 ℃ and be incubated 1～24 hour thermal treatment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 94104443 CN1102821A (en) | 1994-04-25 | 1994-04-25 | Method for changing colour of natural sapphire |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 94104443 CN1102821A (en) | 1994-04-25 | 1994-04-25 | Method for changing colour of natural sapphire |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1102821A true CN1102821A (en) | 1995-05-24 |
Family
ID=5031585
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 94104443 Pending CN1102821A (en) | 1994-04-25 | 1994-04-25 | Method for changing colour of natural sapphire |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1102821A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106637417A (en) * | 2016-10-20 | 2017-05-10 | 河北工业大学 | Color changing method of artificial sapphire crystal |
| CN107117989A (en) * | 2017-05-12 | 2017-09-01 | 桂林理工大学 | A kind of colour-changing method of grey-white jade lighter |
| CN107117988A (en) * | 2017-05-12 | 2017-09-01 | 桂林理工大学 | A kind of colour-changing method of cigarette sapphire lighter |
| CN110802052A (en) * | 2019-10-14 | 2020-02-18 | 江苏吉星新材料有限公司 | Method for removing boron carbide on rough surface of sapphire substrate |
| CN113830807A (en) * | 2021-10-14 | 2021-12-24 | 暨南大学 | Preparation method of intrinsic black alumina powder |
-
1994
- 1994-04-25 CN CN 94104443 patent/CN1102821A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106637417A (en) * | 2016-10-20 | 2017-05-10 | 河北工业大学 | Color changing method of artificial sapphire crystal |
| CN106637417B (en) * | 2016-10-20 | 2018-09-28 | 河北工业大学 | A kind of colour-changing method of artificial sapphire crystal |
| CN107117989A (en) * | 2017-05-12 | 2017-09-01 | 桂林理工大学 | A kind of colour-changing method of grey-white jade lighter |
| CN107117988A (en) * | 2017-05-12 | 2017-09-01 | 桂林理工大学 | A kind of colour-changing method of cigarette sapphire lighter |
| CN110802052A (en) * | 2019-10-14 | 2020-02-18 | 江苏吉星新材料有限公司 | Method for removing boron carbide on rough surface of sapphire substrate |
| CN113830807A (en) * | 2021-10-14 | 2021-12-24 | 暨南大学 | Preparation method of intrinsic black alumina powder |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1102821A (en) | Method for changing colour of natural sapphire | |
| JP2773193B2 (en) | Method for producing translucent yttria sintered body | |
| EP0917188A3 (en) | Method for heat treatment of SOI wafer and SOI wafer heat-treated by the method | |
| CN107715863B (en) | Preparation method of anoxic tungsten oxide photocatalyst | |
| GB1571247A (en) | Heat-reflecting filters | |
| EP0107275B1 (en) | Preparation of mn3o4 | |
| Ritzer et al. | Influence of temperature and time on the stability of silver in silica sol-gel glasses | |
| Wu et al. | Evolution in structural and optical properties of stannic oxide xerogel upon heat treatment | |
| Li et al. | CO disproportionation at mild temperatures over partially reduced cerium oxide | |
| US6635309B2 (en) | Process for the color enhancement of gemstones | |
| CN106637417B (en) | A kind of colour-changing method of artificial sapphire crystal | |
| KR100699048B1 (en) | Heat treatment method for blue sapphire | |
| KR100545046B1 (en) | Functional ceramic product radiating negative ions and far infrared rays and manufacturing method of the same | |
| CN113548883A (en) | Continuous white light transparent ceramic material with stable output and preparation method and application thereof | |
| JPS6360269A (en) | Heat-treatment of metallic titanium | |
| ATE146445T1 (en) | DOPED ZINC OXIDE POWDER, ITS PRODUCTION AND CERAMICS PRODUCED THEREOF | |
| Dotto et al. | Irradiation and heating effects in amethyst crystals from Brazil | |
| CN115321569B (en) | Preparation method of diaspore | |
| RU2743679C1 (en) | Method for improving the color characteristics of natural cassiterite by heat treatment | |
| Zhu et al. | Coloration in ceria-doped zirconia induced by reduction heat treatments | |
| Hashemi et al. | Preparation, sintering and electrical behaviour of cobalt, nickel and zinc germanate | |
| González et al. | Protons in neutron-irradiated and thermochemically reduced MgO crystals doped with lithium impurities | |
| CN102923650A (en) | Preparation method of reducing gas for annealing metal material | |
| Yamazaki | Vacuum Heat Treatment. II | |
| JPS564209A (en) | Manufacture of oxide core for discharge-lamp light source |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C01 | Deemed withdrawal of patent application (patent law 1993) | ||
| WD01 | Invention patent application deemed withdrawn after publication |