A kind of gold black water removal and its preparation method and application

Abstract

The present application relates to the technical field of gold processing, and specifically discloses a gold black water removal and its preparation method and application. The gold black water removal includes the following ingredients in parts by weight: 10-20 parts of baking soda, 4-8 parts of betaine, 1-3 parts of anionic surfactant, 6-9 parts of complex, 1-5 parts of stabilizer, 0.6-2.7 parts of enzyme preparation, and 80-100 parts of water; the complex is compounded with gluconolactone and octadecylamine; its preparation method is: baking soda, betaine, anionic surfactant, complex, and stabilizer are put into water, mixed evenly, and gold black water removal is obtained. The gold black water removal of the present application has the advantage of removing black spots without affecting the hardness of gold through the synergistic effect between the raw materials.

Description

Technical Field

[0001] The present application relates to the technical field of gold processing, and in particular to a gold black water removal method and a preparation method and application thereof. Background Art

[0002] Gold is the single substance of the chemical element gold. It is a soft, golden, corrosion-resistant precious metal. Gold is not only regarded as a symbol of beauty and wealth, but also benefits human life with its unique value. It is not only a special currency for storage and investment, but also an important material for the jewelry industry, electronics industry, modern communications, aerospace industry and other sectors.

[0003] In the production process of gold, especially when gold is used as jewelry, some products need laser welding or butt welding due to the need for assembly. Laser welding is a heat conduction processing method that uses laser radiation to heat the surface of the gold jewelry to be processed, and the heat diffuses to the inside through heat conduction. Although the heat-affected zone of the gold jewelry can be more accurately controlled when the product is assembled using the welding processing method, the surface of the gold jewelry will still appear burnt black, that is, the oxides generated during the welding process adhere to the surface of the gold jewelry, which requires timely cleaning of the gold jewelry to restore its quality.

[0004] At present, the way to deal with black spots on gold is to use sulfuric acid, but this will affect the hardness of gold. Therefore, how to remove black spots on gold is a problem that needs to be solved. Summary of the invention

[0005] In order to remove black spots without affecting the hardness of gold, the present application provides a gold black spot removal water and a preparation method and application thereof.

[0006] In the first aspect, the present application provides a method for removing black water with gold, which adopts the following technical solution:

[0007] A method for removing black water by gold comprises the following ingredients in parts by weight: 10-20 parts of baking soda, 15-30 parts of sodium hydroxide, 4-8 parts of betaine, 1-3 parts of anionic surfactant, 6-9 parts of complex, 1-5 parts of stabilizer, 0.6-2.7 parts of enzyme preparation and 80-100 parts of water; the complex is prepared by compounding gluconolactone and octadecylamine.

[0008] By adopting the above technical scheme, the present application adopts baking soda, sodium hydroxide, betaine, anionic surfactant, complex, stabilizer, enzyme preparation and water to mix and compound to obtain gold deblackening water, and the gold deblackening water is used for gold cleaning. Through the synergistic effect of various raw materials, the decontamination rate can be improved while maintaining the excellent hardness of gold. Among them, the decontamination rate is 97.6-99.5%, the surface color is bright and uniform, and the Vickers hardness value is 117.5HV.

[0009] Baking soda is a surfactant that can react with black spots on gold and saponify with the oil on gold to produce sodium fatty acids that are soluble in water without damaging gold, thereby achieving the effect of removing black spots. Sodium hydroxide can also react with black spots on gold. Betaine is extracted from natural plants, has good water solubility, strong foaming properties and stable foam, and can remove black spots. Anionic surfactants can change the properties of the interface between liquids and liquids, and between liquids and solids, enhance the compatibility of the raw materials for black water removal, and enable the raw materials to play a better role, thereby improving the effect of black water removal.

[0010] The complex belongs to a nonionic surfactant. Nonionic surfactants do not exist in an ionic state, have high stability, are not easily affected by the presence of strong electrolytes, are not easily affected by acids and alkalis, and have good compatibility. By working with anionic surfactants, the black spot removal effect can be further improved. In addition, the complex is a compound of gluconolactone and octadecylamine. Gluconolactone is prepared from renewable resource starch and is easy to react with alkylamines to form amine esters. The polyhydroxy structure of the sugar group can form a large number of hydrogen bonds to increase the interaction between surface adsorption molecules, thereby enhancing the strength of the surface adsorption film and extending the life of the foam. Through the synergistic effect of the two, the surface activity, emulsification, foaming, thickening, and stability are enhanced. Therefore, the addition of the complex to the raw materials for removing black water can further improve the removal effect of black spots on gold without affecting the hardness of gold.

[0011] Preferably, the composite is prepared by the following method: octadecylamine and gluconolactone are placed in an ethanol solution, heated, reacted for a period of time, cooled, filtered, washed, and dried to obtain the composite.

[0012] Furthermore, the composite is prepared by the following method: octadecylamine and gluconolactone are placed in an ethanol solution, heated to 45-55° C., reacted for 1-2 hours, cooled, filtered, washed with water 1-3 times, and dried to obtain a composite;

[0013] The mass fraction of the ethanol solution is 95%, and 0.4-0.6 mL is contained in every 1 g of gluconolactone.

[0014] By adopting the above technical scheme and using the above preparation method to prepare the composite, octadecylamine and gluconolactone can be better compounded, which is convenient for forming the composite, making the composite play a better role, and enhancing the effect of gold in removing black water.

[0015] Preferably, the weight ratio of octadecylamine to gluconolactone is (0.6-1.4):1.

[0016] If the amount of octadecylamine added is too large, it will cause a waste of raw materials. If the amount of octadecylamine added is too small, it will not react completely with gluconolactone, affecting the formation of the complex. By adopting the above technical solution, when the amount of octadecylamine and gluconolactone added is within the above range, it is convenient for the two to form a complex better, and it is also convenient for the complex to play a better role, thereby achieving the purpose of removing gold black spots.

[0017] Preferably, the anionic surfactant is one or more of sodium dodecyl sulfate, dioctyl sodium sulfosuccinate, and sodium dodecylbenzene sulfonate.

[0018] Preferably, the stabilizer is one or more of zinc stearate and calcium stearate.

[0019] By adopting the above technical solution, the types of anionic surfactants and stabilizers are limited, which makes it easier for the anionic surfactants and stabilizers to play a role, thereby achieving the purpose of removing gold black spots.

[0020] Preferably, the enzyme preparation is a mixture of protease, lipase and lysozyme, and the weight ratio of protease, lipase and lysozyme is 1:1:1.

[0021] By adopting the above technical solution, the types of enzyme preparations are limited. Protease and lipase can remove oil stains on gold, and lysozyme can break down the β-1,4 glycosidic bond between N-acetylmuramic acid and N-acetylglucosamine in the cell wall, decomposing the insoluble mucopolysaccharide in the cell wall into soluble glycopeptides, causing the cell wall to rupture and the contents to escape, thereby dissolving the bacteria. Through the synergistic effect of the three enzyme preparations, the oil stains and black spots left on the gold due to human sweat can be removed, and bacteria can also be removed.

[0022] Preferably, the gold black water removal method further comprises 2-6 parts of a mixed acid, wherein the mixed acid is a mixture of citric acid and glycolic acid, and the weight ratio of the citric acid to the glycolic acid is 1:1.

[0023] By adopting the above technical scheme, the types of mixed acids are limited. Among them, citric acid and glycolic acid are weaker in acidity, less corrosive to gold, and have stronger chelating ability. They can not only improve the stability of gold in removing black water, but also dissolve other impurities on the surface of gold. Through the synergistic effect between the two, the stability of black water removal can be improved and the impact on the hardness of gold can be reduced.

[0024] In a second aspect, the present application provides a method for preparing gold to remove black water, using the following technical solution:

[0025] A method for preparing gold to remove black water comprises the following steps:

[0026] Put baking soda, sodium hydroxide, betaine, anionic surfactant, complex and stabilizer into water, mix well to obtain gold black water removal.

[0027] As a preference, the mixed acid is added together with the stabilizer.

[0028] By adopting the above technical solution, various raw materials are mixed evenly to obtain black water, which makes it easier for each raw material to play a role and achieves the purpose of removing black spots without affecting the hardness of gold.

[0029] In a third aspect, the present application provides an application of gold in removing black water, using the following technical solution:

[0030] An application of gold to remove black water comprises the following steps:

[0031] Put the gold de-blackening water into an ultrasonic machine, heat it, put in the gold, and after ultrasonicating for a while, take out the gold and wash it.

[0032] Furthermore, an application of gold to remove black water includes the following steps:

[0033] Put the gold deblackening water into an ultrasonic machine, heat it to 60-80℃ at a power of 250-300W, put in the gold, ultrasonicate for 5-8s, take it out and wash it.

[0034] By adopting the above technical solution, gold is placed in black removal water, and under the action of ultrasonic waves, the purpose of removing black spots can be achieved without affecting the hardness of gold.

[0035] In summary, the present application includes at least one of the following beneficial technical effects:

[0036] 1. Since the present application uses alkaline water such as baking soda to remove black water, and utilizes anionic surfactants and non-ionic surfactants, the synergistic effect between the two can enhance compatibility, stability, and emulsification. Under the condition of not affecting the hardness of gold, the purpose of removing black spots is achieved, and the decontamination rate can reach 99.5%, the surface color is bright and uniform, and the Vickers hardness value is maintained at 117.5HV.

[0037] 2. In the present application, citric acid and glycolic acid are preferably used as mixed acids to be added to the raw materials for removing black water. The acidity is relatively weak, the corrosion to gold is relatively small, and the chelating ability is relatively strong. It can not only improve the stability of gold in removing black water, but also dissolve other impurities on the surface of gold. Through the synergistic effect between the two, the stability of black water can be improved, and the impact on the hardness of gold can be reduced. DETAILED DESCRIPTION

[0038] The present application is further described in detail below in conjunction with the specific contents.

[0039] raw material

[0040] The anionic surfactant is dioctyl sodium sulfosuccinate, and the stabilizer is calcium stearate.

[0041] Preparation Example

[0042] Preparation Example 1

[0043] A composite is prepared by the following method:

[0044] 0.6 kg of octadecylamine and 1 kg of gluconolactone were placed in 500 L of 95% ethanol solution, heated to 50° C., reacted for 1.5 hours, cooled, filtered, washed with water 3 times, and dried to obtain a composite.

[0045] Preparation Example 2

[0046] A composite, which is different from Preparation Example 1 in that the amount of octadecylamine added is different. The amount of octadecylamine added in Preparation Example 2 is 1 kg.

[0047] Preparation Example 3

[0048] A composite, which is different from Preparation Example 1 in that the amount of octadecylamine added is different, and the amount of octadecylamine added in Preparation Example 3 is 1.4 kg.

[0049] Example

[0050] Example 1

[0051] A gold black water removal method, the raw material ratio of which is shown in Table 1.

[0052] A method for preparing gold to remove black water comprises the following steps:

[0053] Baking soda, sodium hydroxide, betaine, anionic surfactant, the complex prepared in Preparation Example 1, and a stabilizer are put into water and mixed evenly to obtain gold black water removal.

[0054] Example 2-3

[0055] A method for removing black water by gold, which differs from Example 1 in that the raw material ratio of the method for removing black water by gold is different, and the raw material ratio is shown in Table 1.

[0056] Table 1 Raw materials for gold black water removal in different embodiments (kg)

[0057]

[0058] Embodiment 4-5

[0059] A method for removing black water by gold, which differs from Example 2 in that the raw material ratio of the method for removing black water by gold is different, and the raw material ratio is shown in Table 2.

[0060] Table 2 Raw materials for gold black water removal in different embodiments (kg)

[0061]

[0062] Example 6

[0063] A gold-based black water remover, which differs from Example 4 in that the source of the composite is different, and is prepared using Preparation Example 2.

[0064] Example 7

[0065] A gold-based black water remover, which differs from Example 4 in that the source of the composite is different, and is prepared using Preparation Example 3.

[0066] Examples 8-10

[0067] A gold black water removal method, which differs from Example 6 in that mixed acid is added to the raw materials for black water removal, and the raw material ratio is shown in Table 3.

[0068] Table 3 Raw materials for gold black water removal in different embodiments (kg)

[0069]

[0070] Comparative Example

[0071] Comparative Example 1

[0072] A method for removing black water by gold, which differs from Example 1 in that no composite material is added to the raw material for removing black water by gold.

[0073] Comparative Example 2

[0074] A method for removing black water by gold, which differs from Example 1 in that an equal amount of the complex in the raw material for removing black water by gold is replaced by octadecylamine.

[0075] Comparative Example 3

[0076] A method for removing black water by gold, which differs from Example 1 in that an equal amount of the complex in the raw material for removing black water by gold is replaced by gluconolactone.

[0077] Comparative Example 4

[0078] A gold deblackening water method, which differs from Example 1 in that an equal amount of the complex in the gold deblackening water raw material is replaced by fatty acid polyoxyethylene ester.

[0079] Comparative Example 5

[0080] A gold deblackening water, which is different from Example 1 in that the gold deblackening water is 40kg of a hydrochloric acid solution with a mass fraction of 38% and 15kg of a nitric acid solution with a mass fraction of 65%.

[0081] Application Examples

[0082] Application Example 1

[0083] An application of gold to remove black water comprises the following steps:

[0084] The gold deblackening water prepared in Example 1 was put into an ultrasonic machine, heated to 70°C at a power of 275W, and gold was put in. After ultrasonic treatment for 6s, the gold was taken out and washed.

[0085] Application Example 2-10

[0086] The application of gold deblackening water in Application Example 2-10 is different from that in Application Example 1 in that the gold deblackening water in Application Example 2-10 is prepared using Examples 2-10.

[0087] Application Comparative Examples 1-5

[0088] The application of the gold deblackening water in Application Examples 1-5 is different from Application Example 1 in that the gold deblackening water in Application Examples 1-5 is prepared by using Comparative Examples 1-5 respectively.

[0089] Performance testing

[0090] The following performance tests were performed on the gold in the corresponding use cases 1-10 and the comparative application examples 1-5:

[0091] Decontamination rate: 75 gold jewelry made from the same batch under the same process conditions and with basically the same oxidation area were selected, and the oxidation area was recorded as S1. Five pieces were grouped together, and each group was cleaned using the methods of Application Examples 1-10 and Comparative Examples 1-5. After cleaning, the gold jewelry was left to stand for 30 minutes, and the size of the oxidation area on the surface of the gold jewelry after decontamination was observed and measured, recorded as S2. The decontamination rate of each group of gold jewelry was calculated, and the average value was taken as the final result. The results are shown in Table 4:

[0092] Decontamination rate = (S1-S2) / S1×100%

[0093] Surface color: The surface color of the gold after decontamination was observed. The results are shown in Table 4.

[0094] Vickers hardness value: The Vickers hardness of the electrodeposited layer was measured using a microhardness tester. The loading force was 0.98 N, the loading time was 8 s, and the hardness of the gold before cleaning was 117.5 HV. The results are shown in Table 4.

[0095] Table 4 Test results

[0096]

[0097]

[0098] It can be seen from the combination of application examples 1-10 and comparative application examples 1-5 that the gold black water removal of the present application can improve the decontamination rate while maintaining the excellent hardness of gold through the synergistic effect of various raw materials. Among them, the decontamination rate is 97.6-99.5%, the surface color is bright and uniform, and the Vickers hardness value is 117.5HV.

[0099] Combining Application Example 1 and Application Comparative Examples 1-3, it can be seen that the decontamination rate of Application Example 1 is 97.6%, the surface color is bright and uniform, and the Vickers hardness value is 117.5HV, which is better than Application Comparative Examples 1-3, indicating that it is more appropriate to add the complex to the raw material for removing black water from gold. Through the synergistic effect between octadecylamine and gluconolactone, the decontamination rate can be improved while ensuring the excellent hardness of gold, and the black spots on the gold can be removed.

[0100] Combining Application Example 1 and Application Comparative Example 4, it can be seen that the decontamination rate of Application Example 1 is 97.6%, the surface color is bright and uniform, and the Vickers hardness value is 117.5HV, which is better than Application Comparative Example 4, indicating that it is more appropriate to use the complex as a non-ionic surfactant in gold black water removal, and it can further improve the removal of black spots without affecting the hardness of gold.

[0101] Combining Application Example 1 and Application Comparative Example 5, it can be seen that the decontamination rate of Application Example 1 is 97.6%, the surface color is bright and uniform, and the Vickers hardness value is 117.5HV, which is better than Application Comparative Example 5, indicating that it is more appropriate to use the technical solution of the present application to remove black spots on gold. While maintaining a high decontamination rate, it will not affect the hardness of gold.

[0102] Combining Application Examples 1-3, it can be seen that the decontamination rate of Application Example 2 is 98.1%, the surface color is bright and uniform, and the Vickers hardness value is 117.5HV, which is better than other application examples, indicating that the addition amount of the composite in Application Example 2 is more appropriate, which can improve the decontamination rate while maintaining the excellent hardness of gold.

[0103] Combining Application Examples 4, 6-7, it can be seen that the decontamination rate of Application Example 6 is 98.9%, the surface color is bright and uniform, and the Vickers hardness value is 117.5HV, which is better than other application examples, indicating that the composite prepared by Preparation Example 2 is more suitable and can improve the decontamination rate while maintaining the excellent hardness of gold.

[0104] Combining Application Examples 6 and 8-10, it can be seen that the decontamination rate of Application Example 9 is 99.5%, the surface color is bright and uniform, and the Vickers hardness value is 117.5HV, which is better than other application examples. This shows that it is more appropriate to add mixed acid to the raw materials for gold deblackening, which can further improve the decontamination rate while maintaining the excellent hardness of gold.

[0105] The above-mentioned specific implementation examples are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, all equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A gold black water removal method, characterized in that: The invention comprises the following ingredients in parts by weight: 10-20 parts of baking soda, 15-30 parts of sodium hydroxide, 4-8 parts of betaine, 1-3 parts of anionic surfactant, 6-9 parts of complex, 1-5 parts of stabilizer, 0.6-2.7 parts of enzyme preparation and 80-100 parts of water; the complex is prepared by compounding gluconolactone and octadecylamine; the enzyme preparation is a mixture of protease, lipase and lysozyme, and the weight ratio of the protease, lipase and lysozyme is 1:1:

1.

2. A gold black water removal method according to claim 1, characterized in that: The composite is prepared by the following method: octadecylamine and gluconolactone are placed in an ethanol solution, heated, reacted for a period of time, cooled, filtered, washed, and dried to obtain the composite.

3. A gold black water removal method according to claim 2, characterized in that: The weight ratio of octadecylamine to gluconolactone is (0.6-1.4):

1.

4. The gold black water removal method according to claim 1, characterized in that: The anionic surfactant is one or more of sodium dodecyl sulfate, dioctyl sodium sulfosuccinate, and sodium dodecylbenzene sulfonate.

5. The gold black water removal method according to claim 1, characterized in that: The stabilizer is one or more of zinc stearate and calcium stearate.

6. The gold black water removal method according to claim 1, characterized in that: The gold black water removal method also includes 2-6 parts of a mixed acid, which is a mixture of citric acid and glycolic acid, and the weight ratio of the citric acid to the glycolic acid is 1:

1.

7. A method for preparing gold to remove black water as claimed in any one of claims 1 to 5, characterized in that: The steps include: Put baking soda, sodium hydroxide, betaine, anionic surfactant, complex, stabilizer and enzyme preparation into water, mix well to obtain golden black water removal.

8. The method for preparing gold to remove black water according to claim 7, characterized in that: When adding the stabilizer, add the mixed acid at the same time.

Images