Application of mercaptopropyltrimethoxysilane as collecting agent in zinc oxide flotation

Abstract

The invention belongs to the technical field of mineral processing, and relates to application of mercaptopropyltrimethoxysilane as a collecting agent in zinc oxide flotation. Mercaptopropyltrimethoxysilane and octadecylamine are combined to serve as a combined collecting agent for cooperative bubble control, the flotation process is shortened, the enrichment effect and the separation index of zinc oxide minerals in the ore are improved, most of zinc oxide minerals in the ore can be recycled only through one-time zinc oxide flotation operation, and the recovery rate of the zinc oxide minerals in the ore is increased. And the zinc grade in the concentrate can be ensured, and short-process flotation recovery of zinc oxide minerals is achieved. According to the method, middlings generated by flotation are not returned, so that accumulation and circulation of slime and an activating agent in a flotation system are avoided, and the deterioration influence of foam on flotation indexes is eliminated. According to the method, the sorting process is simplified, the production energy consumption and cost are reduced, the problem of efficient and clean utilization of zinc oxide is solved, and the method has remarkable economic and environmental benefits.

Description

Technical Field

[0001] The present invention relates to the application of mercaptopropyltrimethoxysilane as a collector in the flotation of zinc oxide, belonging to the technical field of mineral separation. Background Art

[0002] Zinc is an important non-ferrous metal, widely used in fields such as galvanizing, batteries, alloys, etc. With the increasing depletion of high-grade zinc ore resources, the development and utilization of low-grade zinc oxide ores have received more and more attention. However, the mineral composition of low-grade zinc oxide ores is complex, often associated with gangue minerals such as limonite, hematite, quartz, and calcite. There are many types of zinc oxide minerals, such as smithsonite, hemimorphite, hydrozincite, etc., with large differences in floatability, fine dissemination size, and difficult monomer dissociation. The surface properties are complex: the surface of zinc oxide minerals is prone to oxidation, dissolution, adsorption, etc., resulting in unstable surface properties and affecting the flotation effect.

[0003] The sulfide amine method for flotation is to use amine collectors for adsorption on the surface of zinc oxide minerals for flotation. This method has good effects on certain zinc oxide minerals (such as smithsonite), but it faces a significant problem in practical applications: the foam problem. Specifically, there are problems such as excessive foam, too high foam stability, and serious accumulation of the foam layer. These problems will make the flotation process difficult to control, affecting the separation efficiency and equipment operation. The foam problem of the sulfide amine method is one of the main factors restricting the wide application of this method in the flotation of zinc oxide ores. Therefore, it is urgent to develop new and efficient flotation reagents and technological processes to eliminate the influence of foam on zinc oxide flotation, economically and efficiently recover such zinc ore resources, and provide technical support for the green and efficient utilization of complex and refractory zinc oxide resources. Summary of the Invention

[0004] To solve the above problems, the present invention uses mercaptopropyltrimethoxysilane as a collector in the flotation of zinc oxide. After combining mercaptopropyltrimethoxysilane with octadecylamine, they are used as a combined collector for synergistic foam control, shortening the flotation process, improving the enrichment effect and separation index of zinc oxide minerals in the ore, and recovering most of the zinc oxide minerals in the ore through only one zinc oxide flotation operation. The middlings produced by the flotation of the present invention are not returned, which avoids the accumulation and circulation of slime and activator in the flotation system, and eliminates the deteriorating influence of foam on the flotation index. The present invention simplifies the separation process, reduces production energy consumption and costs, solves the problem of efficient and clean utilization of zinc oxide, and has significant economic and environmental benefits.

[0005] The technical solution of the present invention is: combine mercaptopropyltrimethoxysilane with octadecylamine, and use this combined collector for the sulfide amine method to float and recover low-grade zinc oxide, wherein the mass ratio of mercaptopropyltrimethoxysilane to octadecylamine is 1 - 1.2:5.

[0006] Preferably, the recovery method specifically includes the following steps:

[0007] (1) Grinding: When grinding low-grade zinc oxide ore, add 750 - 1250 g / t of sodium carbonate and 750 - 1250 g / t of sodium sulfide, and grind to obtain pulp;

[0008] (2) Sphalerite flotation: Add collector Ⅰ to the pulp obtained in step (1). Collector Ⅰ is a combination of amyl xanthate and ethyl thionocarbamate in a mass ratio of 0.9 - 1.1:1, with a dosage of 150 - 250 g / t, and add 12 - 18 g / t of frother no. 2 oil. After a one-stage sphalerite flotation operation, sphalerite concentrate and sphalerite tailings are obtained;

[0009] (3) Zinc oxide flotation: Add sodium sulfide as an activator to the sphalerite tailings obtained in step (2), where the dosage of sodium sulfide is 4500 - 7500 g / t; then add a combination inhibitor of sodium silicate and sodium hexametaphosphate in a mass ratio of 0.9 - 1.1:1, with a dosage of 400 - 600 g / t; add 300 - 500 g / t each of collector Ⅰ and collector Ⅱ, add frother no. 2 oil, and after a one-stage zinc oxide flotation operation, zinc oxide concentrate and tailings are obtained.

[0010] Preferably, in the pulp of the present invention, the fineness of minerals -200 mesh accounts for 85 - 90%; or the relative dissociation between useful minerals and between useful minerals and gangue minerals is achieved.

[0011] Preferably, the sphalerite flotation operation time in step (2) is 10 minutes.

[0012] Preferably, in step (3), a combination collector of mercaptopropyltrimethoxysilane and octadecylamine is used for zinc oxide sulfide amine flotation, denoted as collector Ⅱ.

[0013] Preferably, in step (3), the zinc oxide flotation operation time is 10 minutes, the activator is sodium sulfide, with a dosage of 4500 - 7500 g / t; the dosage of the combination inhibitor is 400 - 600 g / t; the dosages of collector Ⅰ and collector Ⅱ are each 300 - 500 g / t, and the addition amount of the frother is 12 - 18 g / t.

[0014] The zinc oxide ore in the present invention is low-grade zinc oxide ore, the main zinc mineral is smithsonite, and the main gangue minerals are calcite and dolomite.

[0015] In the present invention, mercaptopropyltrimethoxysilane has good defoaming ability and selective defoaming mechanism for octadecylamine, and at the same time, the mercapto group in the molecule has a collecting effect, which can ensure the recovery rate of zinc oxide.

[0016] The principle of the present invention:

[0017] (1) Mercaptopropyltrimethoxysilane has the effect of reducing the surface tension of the foam liquid film of octadecylamine. Mercaptopropyltrimethoxysilane and octadecylamine are alternately adsorbed at the metal sites on the mineral surface. This adsorption form prevents the non-polar groups of octadecylamine from hydrophobic association, thereby enhancing the collecting ability of octadecylamine. At the same time, the dispersion of the non-polar groups of octadecylamine also reduces the foam viscosity, thus shortening the foam duration.

[0018] (2) The mercapto functional group in the molecular structure of mercaptopropyltrimethoxysilane has significant collecting characteristics, which can effectively compensate for the mineral loss caused by foam rupture, thereby significantly improving the flotation recovery rate.

[0019] (3) The combined collecting of mercaptopropyltrimethoxysilane and octadecylamine has both collecting ability and selectivity. Qualified-grade zinc oxide concentrate can be obtained only through a single-stage oxidative flotation operation, while the zinc recovery rate in the tailings is relatively low, thus greatly shortening the flotation process.

[0020] Advantages of the present invention:

[0021] (1) The mercaptopropyltrimethoxysilane used in the present invention has excellent defoaming performance, which can specifically eliminate the foam generated by octadecylamine and achieve selective defoaming.

[0022] (2) Compared with the traditional octadecylamine flotation method, the high-efficiency combined collector used in the present invention has a weak foam accumulation phenomenon while maintaining the zinc recovery rate, solving the contradiction between defoaming and recovery rate.

[0023] (3) The present invention provides a combined collector of sulfonamide method and its application for low-grade zinc oxide ore, which can efficiently recover the refractory zinc oxide ore stored in the mine, and at the same time effectively relieve the environmental pressure caused by ore storage. This process has the characteristics of good defoaming effect, less reagent consumption, strong adaptability, etc., and can significantly improve the economic benefits of enterprises. Description of the drawings

[0024] Figure 1 It is the flotation flow chart of the present invention;

[0025] Figure 2 It is the flotation foam diagram of Example 1 of the present invention;

[0026] Figure 3 It is the flotation foam diagram of Example 2 of the present invention;

[0027] Figure 4 It is the flotation foam diagram of Example 3 of the present invention;

[0028] Figure 5 It is the flotation foam diagram of Comparative Example 1 of the present invention;

[0029] Figure 6This is the flotation foam diagram of Comparative Example 2 of the present invention. Detailed implementation manners

[0030] The present invention will be further described in detail below in conjunction with specific embodiments, but the protection scope of the present invention is not limited to the content described.

[0031] Example 1

[0032] Mineral raw materials

[0033] The mineral used in Example 1 is derived from a low-grade zinc oxide ore in Lanping, Yunnan. The total zinc grade is 5.23%, and the zinc minerals are mainly smithsonite. The dosage of the reagents is shown in Table 1.

[0034] Table 1 Reagent dosage in Example 1

[0035]

[0036]

[0037] The specific operation steps are as follows:

[0038] (1) Add 1000 g / t of sodium carbonate and 1000 g / t of sodium sulfide during the grinding of the low-grade zinc oxide ore to obtain pulp.

[0039] (2) Add collector I with a mass ratio of amyl xanthate to ethyl thionocarbazide of 1:1 to the pulp obtained in step (1), with a dosage of 200 g / t, add foaming agent No. 2 oil, and obtain zinc sulfide concentrate and zinc sulfide tailings after a one-stage roughing process.

[0040] (3) Add sodium sulfide as an activator to the zinc sulfide tailings obtained in step (2), with a sodium sulfide dosage of 6000 g / t; then add a combined inhibitor with a mass ratio of water glass to sodium hexametaphosphate of 1:1, with a dosage of 500 g / t; add 400 g / t of each of collector I and collector II, add foaming agent No. 2 oil, and obtain zinc oxide concentrate and tailings after a one-stage zinc oxide flotation operation.

[0041] The foam effect is shown in Figure 2 .

[0042] The product indexes are shown in Table 2.

[0043] Table 2 Flotation product indexes of Example 1

[0044] Operation product Yield (%) Zn grade (%) Zn recovery rate (%) Zinc sulfide concentrate 9.55 5.07 9.26 Zinc oxide concentrate 19.53 20.13 75.17 Tailings 70.92 1.15 15.57 Raw ore 100.00 5.23 100.00

[0045] From Figure 2As can be seen from the results in Table 2, when the method of the present invention is used for the flotation of low-grade zinc oxide by the sulfide amine method, the zinc oxide concentrate obtained in Example 1 has a zinc grade of 20.13% and a zinc recovery rate of 75.17%, and there is almost no foam accumulation. This shows that the octadecylamine in Example 1 has a significant defoaming effect and at the same time produces high-quality zinc oxide concentrate.

[0046] Example 2

[0047] Mineral raw material

[0048] The mineral source used in the examples of the present invention is the same as that in Example 1 but with a lower grade, and the total zinc grade is 4.51%. Among them, the zinc minerals are mainly smithsonite. The reagent dosages are shown in Table 3.

[0049] Table 3 Reagent Dosages in Example 2

[0050]

[0051] The specific operation steps are the same as those in Example 1.

[0052] The foam effect is shown in Figure 3 .

[0053] The product indexes are shown in Table 4.

[0054] Table 4 Flotation Product Indexes in Example 2

[0055] Operation product Yield (%) Zn grade (%) Zn recovery rate (%) Zinc sulfide concentrate 9.32 4.47 9.24 Zinc oxide concentrate 17.53 19.78 76.88 Tailings 73.15 0.86 13.88 Raw ore 100.00 4.51 100.00

[0056] From Figure 3 As can be seen from the results in Table 4, when the method of the present invention is used for the flotation of low-grade zinc oxide by the sulfide amine method, the zinc oxide concentrate obtained in Example 2 has a zinc grade of 19.78% and a zinc recovery rate of 76.88%, and there is almost no foam accumulation. This shows that the octadecylamine in Example 2 has a significant defoaming effect and at the same time produces high-quality zinc oxide concentrate.

[0057] Example 3

[0058] Mineral raw material

[0059] The mineral used in the examples of the present invention is from Liangshan, Sichuan, with a total zinc grade of 5.98%. Among them, the zinc minerals are mainly smithsonite. The reagent dosages are shown in Table 5.

[0060] Table 5 Reagent Dosages in Example 3

[0061]

[0062] The specific operation steps are the same as those in Example 1.

[0063] The foam effect is shown in Figure 4 .

[0064] The product indicators are shown in Table 6.

[0065] Table 6 Flotation product indicators of Example 3

[0066] Operation product Yield (%) Zn grade (%) Zn recovery rate (%) Zinc sulfide concentrate 9.67 5.84 9.44 Zinc oxide concentrate 22.53 20.98 79.04 Tailings 67.80 1.02 11.51 Raw ore 100.00 5.98 100.00

[0067] From Figure 4 From the results in Table 6, it can be seen that when the method of the present invention is used for the flotation of low-grade zinc oxide by the sulfide amine method, the zinc oxide concentrate with a zinc grade of 20.98% and a zinc recovery rate of 79.04% is obtained in Example 3, and there is almost no foam accumulation. This shows that the octadecylamine in Example 3 has a significant defoaming effect, and at the same time, high-quality zinc oxide concentrate is produced.

[0068] Comparative Example 1

[0069] The mineral raw materials used in this example are the same as those in Example 1. The collector II is replaced by only using octadecylamine, and the dosages of the other reagents are the same as those in Example 1. The reagent dosages are shown in Table 7

[0070] Table 7 Reagent dosages of Comparative Example 1

[0071]

[0072] The specific operation steps are as follows:

[0073] (1) Add 1000 g / t of sodium carbonate and 1000 g / t of sodium sulfide during the grinding of low-grade zinc oxide ore to obtain pulp.

[0074] (2) Add collector I with a mass ratio of amyl xanthate to ethyl thionocarbamate of 1:1 and a dosage of 200 g / t to the pulp obtained in step (1), add foaming agent No. 2 oil, and obtain zinc sulfide concentrate and zinc sulfide tailings after a one-stage roughing process.

[0075] (3) Add sodium sulfide as an activator to the zinc sulfide tailings obtained in step (2), with a sodium sulfide dosage of 6000 g / t; then add a combined inhibitor with a mass ratio of water glass to sodium hexametaphosphate of 1:1 and a dosage of 500 g / t; add 400 g / t of collector I and octadecylamine respectively, add foaming agent No. 2 oil, and obtain zinc oxide concentrate and tailings after a one-stage zinc oxide flotation operation.

[0076] The foam effect is shown in Figure 5 .

[0077] The product indicators are shown in Table 8.

[0078] Table 8 Flotation product indicators of Comparative Example 1

[0079] Operation product Yield (%) Zn grade (%) Zn recovery rate (%) Zinc sulfide concentrate 9.54 5.08 9.28 Zinc oxide concentrate 20.18 16.61 64.21 Tailings 70.28 1.97 26.50 Raw ore 100.00 5.22 100.00

[0080] From Figure 5As can be seen from the results in Table 8, when the sulfonamide flotation method is used for low-grade zinc oxide ore, in Comparative Example 1, zinc oxide concentrate with a zinc grade of 16.61% and a zinc recovery rate of 64.21% was obtained; the foam accumulation phenomenon was serious, and gangue minerals were easily entrained, resulting in a decrease in the concentrate grade. Closed-circuit circulation could not be effectively carried out.

[0081] Comparative Example 2

[0082] The mineral raw materials used in this example are the same as those in Example 1. Tributyl phosphate, a conventional defoamer, was added, and the other reagents are the same as those in Comparative Example 1. The reagent dosages are shown in Table 9.

[0083] Table 9 Reagent Dosages in Comparative Example 2

[0084]

[0085] The foam effect is shown in Figure 6 .

[0086] The product indexes are shown in Table 10.

[0087] Table 10 Flotation Product Indexes in Comparative Example 2

[0088] Operation product Yield (%) Zn grade (%) Zn recovery rate (%) Zinc sulfide concentrate 9.46 5.08 9.21 Zinc oxide concentrate 21.31 6.11 24.94 Tailings 69.23 4.97 65.85 Raw ore 100.00 5.22 100.00

[0089] From Figure 6 As can be seen from the results in Table 10, when tributyl phosphate is used as a defoamer for the sulfonamide flotation method of low-grade zinc oxide ore, in Comparative Example 2, zinc oxide concentrate with a zinc grade of 6.11% and a zinc recovery rate of 24.94% was obtained; the foam accumulation phenomenon was not obvious, but the addition of tributyl phosphate caused the collector to lose its selective collecting ability for the target minerals, and the separation efficiency was low.

[0090] By comparing Example 1 with the two comparative examples, it can be found that there are obvious defects in the treatment of low-grade zinc oxide ore by the sulfonamide flotation method without adding a defoamer and adding the traditional defoamer tributyl phosphate. In Comparative Example 1, due to the non-use of a defoamer, although the recovery rate and grade of zinc oxide concentrate were high, the foam accumulation was serious, resulting in difficulty in carrying out closed-circuit circulation. In Comparative Example 2, after using tributyl phosphate as a defoamer, the foam phenomenon was significantly weakened, however, the grade and recovery rate of zinc oxide concentrate decreased significantly. The traditional sulfide flotation method for zinc oxide ore has great limitations in treating this type of zinc oxide ore and cannot efficiently recover zinc minerals. The three examples of the present invention show that compared with the traditional sulfide flotation method for zinc oxide ore, the flotation method of the present invention can ensure the grade and recovery rate of zinc oxide concentrate while effectively eliminating foam, and can more effectively achieve the high-quality recovery of low-grade zinc oxide ore. The mercaptopropyltrimethoxysilane defoaming flotation used has good and stable effects.

Claims

1. The application of mercaptopropyltrimethoxysilane as a collector in zinc oxide flotation is characterized in that: Mercaptopropyltrimethoxysilane is combined with octadecylamine, and the combined collector is used for flotation recovery of low-grade zinc oxide by sulfidation amine method, wherein the mass ratio of mercaptopropyltrimethoxysilane to octadecylamine is 1-1.2:

5.

2. The use of mercaptopropyltrimethoxysilane as a collector in zinc oxide flotation according to claim 1, characterized in that: The specific steps of flotation recovery of low-grade zinc oxide ore by sulfidation amine method are as follows: (1) Grinding: adding 750-1250 g / t of sodium carbonate as a dispersant and 750-1250 g / t of sodium sulfide as an activator to the raw ore to obtain ore pulp; (2) zinc sulfide flotation: adding collector I to the ore pulp obtained in step (1), wherein collector I is a combination of amyl xanthate and ethyl thiocyanate in a mass ratio of 0.9-1.1:1, and the amount used is 150-250 g / t, and adding frother oil 12-18 g / t, and performing a roughing process to obtain zinc sulfide concentrate and zinc sulfide tailings; (3) Zinc oxide flotation: Sodium sulfide is added to the zinc sulfide tailings obtained in step (2) as an activator, wherein the amount of sodium sulfide is 4500-7500 g / t; then a combined inhibitor of water glass and sodium hexametaphosphate in a mass ratio of 0.9-1.1:1 is added in an amount of 400-600 g / t; a combined collector I and a collector II in a mass ratio of mercaptopropyltrimethoxysilane to octadecylamine of 1-1.2:5 are added in an amount of 300-500 g / t each, and a frother No. 2 oil of 12-18 g / t is added to obtain zinc oxide concentrate and tailings in a single flotation process.

3. The use of mercaptopropyltrimethoxysilane as a collector in zinc oxide flotation according to claim 2, characterized in that: The fineness of the ore ground in step (1) is less than 0.074 mm and the content is 85-90%.

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