Activating, collecting and floating method for low-grade zinc oxide ore

Abstract

The invention relates to the technical field of lead zinc ore flotation, in particular to a low-grade zinc oxide ore activating, collecting and flotation method. The method comprises the following steps: grinding low-grade zinc ore with the zinc content of 2% into 80% from 200 meshes by adjusting the grinding fineness of the raw ore; sodium sulfide and copper sulfate are added according to the gradient of 15: 1, sodium sulfide is adopted in advance to react with calamine and smithsonite, then copper sulfate is added on the surface of sphalerite to form copper sulfide precipitates, and then the copper sulfide precipitates chemically react with a compound agent of fatty acid, palmitic acid and lauric acid to generate thioester and a thiocompound thereof. And the composite agent further covers the surface of the mineral to form a hydrophobic film, the surface of the oxidized mineral generates an adsorption effect, the zinc ore is easy to float under the action of the composite agent in the ore pulp of Na2S and copper sulfate systems, and finally the purpose of separating the vein ore from the zinc ore is achieved. The invention aims to solve the problems of poor activation and collection efficiency and high unit cost of the traditional medicament on one hand, and solve the problem of how to improve the lead-zinc recovery rate and grade of low-grade minerals on the other hand.

Description

Technical Field

[0001] The invention relates to the technical field of lead-zinc ore flotation, and in particular to an activation capture flotation method for low-grade zinc oxide ore. Background Art

[0002] Zinc ore resources mainly include zinc sulfide ore and zinc oxide ore. Zinc sulfide ore accounts for 80% and zinc oxide ore accounts for about 20%. Due to the large amount of zinc sulfide ore resources and the relatively easy ore dressing and recovery, more than 95% of zinc currently comes from zinc sulfide ore resources. The ore dressing and recovery of zinc oxide ore is very difficult and the ore dressing recovery rate is low. So far, there is no effective ore dressing method applied to industry. In today's shortage of zinc ore resources, the efficient use of zinc oxide ore resources has always been a hot issue for ore dressing workers.

[0003] In the process of conceiving and realizing the present application, the inventors found that due to the complex mineral composition of low-grade zinc oxide ore, the minerals are embedded with a variety of different mineral types, and the ore has differences in physical and chemical properties, which makes selectivity in the flotation process difficult. In addition, due to the low zinc grade, the content of useful components in the mineral is relatively small, which increases the difficulty of flotation. Traditional single-drug flotation methods usually achieve separation through differences in the physical and chemical properties of the surface of mineral particles, but in low-grade zinc oxide ores, the differences are often not significant enough. Fine-grained mineral particles are prone to form agglomerates due to their large specific surface area and high surface energy, which increases production cost investment and easily causes deviations in flotation indicators. In summary, the beneficiation treatment of low-grade zinc oxide ore is challenging.

[0004] The prior art CN111266195B discloses "A combined collector for flotation of zinc oxide ore and its application". Although the invention discloses a method for preparing the collector, this method is mainly aimed at hemimorphite and smithsonite in dolomite gangue minerals. The original ore contains mud and has a high zinc content, and is not suitable for zinc oxide ore with a lower zinc grade.

[0005] Therefore, there is a need for an activated capture flotation method for low-grade zinc oxide ore, which can improve the zinc recovery rate of the zinc ore through cascade activated capture.

[0006] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0007] The main purpose of the present invention is to provide a low-grade zinc oxide ore activation capture flotation method, aiming to solve the problem of how to improve the lead and zinc recovery rate of low-grade zinc oxide ore through the step-by-step activation capture effect of an activator and a composite reagent.

[0008] To achieve the above object, the present invention provides a low-grade zinc oxide ore activation capture flotation method, the method comprising:

[0009] S1, grinding a low-grade zinc oxide ore having a zinc content of 2% to obtain a grinding slurry; the grinding slurry has a grinding fineness of -200 mesh accounting for 80%;

[0010] S2, adding sodium sulfide activator to the grinding slurry in advance, and stirring to obtain slurry I;

[0011] S3, adding copper sulfate activator to the slurry I again, and stirring to obtain slurry II;

[0012] S4, after adding composite reagents to the ore pulp II for collection, it is subjected to two roughing selections, one fine selection and one scavenging selection to obtain zinc oxide concentrate, wherein the composite reagents include fatty acid, palmitic acid and lauric acid.

[0013] Optionally, the low-grade zinc oxide ore includes: hemimorphite, smithsonite, and sphalerite.

[0014] Optionally, the low-grade zinc oxide ore further includes gangue minerals, and the gangue minerals include calcite and dolomite.

[0015] Optionally, the zinc content in the low-grade zinc oxide ore is ≤2%.

[0016] Optionally, the stirring time in S1 is ≥5 min.

[0017] Optionally, the stirring time in S2 is ≥ 6 min.

[0018] Optionally, the dosage ratio of the sodium sulfide activator to the copper sulfate activator is 15:1.

[0019] Optionally, the sodium sulfide activator is used in an amount of 1500 g / t, and the copper sulfate activator is used in an amount of 100 g / t.

[0020] Principle of the invention:

[0021] The present invention mainly utilizes sodium sulfide to react with hemimorphite and smithsonite, and simultaneously precipitates copper sulfate on the surface of sphalerite to form copper sulfide precipitation, and then reacts with fatty acid, palmitic acid, and lauric acid. The compound reagent undergoes a chemical reaction to generate thioesters and thio compounds, which then cover the surface of the mineral to form a hydrophobic film, and the surface of the oxidized mineral produces an adsorption effect. In the ore pulp of the copper sulfate and Na2S system, the zinc ore is easily floated by the composite reagent, and the purpose of separating the vein ore from the zinc ore is finally achieved; by adding copper sulfate and sodium sulfide successively, the staged activation of sphalerite, hemimorphite, and smithsonite is achieved. Among them, sodium sulfide is activated for hemimorphite and smithsonite, and copper sulfate is used to activate sphalerite to form a step-by-step activation effect. Finally, on the basis of activation, the composite reagent of fatty acid, palmitic acid, and lauric acid is used for capture to further improve the flotation efficiency of the mineral.

[0022] The present invention provides a method for activating and collecting flotation of low-grade zinc oxide ore, which at least has the following characteristics:

[0023] Beneficial effects:

[0024] 1. By grinding the raw ore to -200 mesh, accounting for 80%, adding activator and compound reagent in stages, and controlling the stirring time, the flotation recovery of sphalerite, hemimorphite and smithsonite can be achieved, which improves the recovery rate of lead and zinc compared with the traditional sulfide xanthate flotation method;

[0025] 2. When flotation beneficiation is performed on low-grade zinc oxide ore, the present invention adopts a step activation method, which has a strong activation and collection effect on hemimorphite and smithsonite containing calcite and dolomite gangue minerals, and effectively improves the flotation recovery rate of low-grade zinc oxide;

[0026] 3. The cascade activation recovery process provided by the present invention can reduce the dosage of reagents by one third compared with the traditional process, and the process operation is simple and the method is convenient;

[0027] 4. The present invention can effectively solve the problem of reverse flotation foam viscosity by adding sodium sulfide activator, copper sulfate activator and composite reagent step by step to fully activate the consumed reagents. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the process of the present invention.

[0029] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0030] In order to better understand the above technical solution, exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0031] Based on the above description, an embodiment of the activation capture flotation method of low-grade zinc oxide ore of the present invention is proposed.

[0032] First embodiment

[0033] Experimental steps:

[0034] 1. Sodium sulfide and copper sulfate are used as activators, and fatty acid, palmitic acid and lauric acid compound agents are used as collectors;

[0035] 2. Grinding low-grade zinc oxide ore to obtain grinding slurry; the grinding slurry has a grinding fineness of -200 mesh accounting for 80%;

[0036] 3. Pre-adding sodium sulfide activator to the grinding slurry, stirring and reacting for ≥5 minutes to obtain slurry I;

[0037] 4. Add copper sulfate activator to the obtained slurry I again, and stir the reaction for ≥6 minutes to obtain slurry II;

[0038] 5. Add composite reagents to the ore pulp II and collect it through two roughing selections, one fine selection and one scavenging selection to obtain zinc oxide concentrate.

[0039] For example: according to the process pre-selection, 1500g / t of sodium sulfide, 100g / t of copper sulfate, and 50g / t of composite collector (used as raw solution) are used. The specific usage amounts need to be adjusted based on the mutual content of lead and zinc in the sulfide tailings.

[0040] The feed content of the closed-circuit test of oxide ore positive flotation was 1.57% Zn, the obtained zinc oxide concentrate contained 18.86% Zn, and the Zn recovery rate was 71.83%.

[0041] According to the test results, for low-grade zinc oxide minerals, which are mainly hemimorphite and smithsonite, with a small amount of sphalerite inclusions and a high content of gangue minerals (mainly calcite and dolomite), when the zinc grade is low (the zinc content of the original ore is ≤2%), the low-grade lead-zinc oxide ore can be recovered through the cascade activation capture flotation method.

[0042] Second embodiment

[0043] The same batch of low-grade zinc oxide ore was used for flotation as in the first embodiment.

[0044] Experimental steps:

[0045] 1. Sodium sulfide and copper sulfate are used as activators, and fatty acid, palmitic acid, and lauric acid compound agents are used as collectors;

[0046] 2. Grinding low-grade zinc oxide ore to obtain grinding slurry; the grinding slurry has a grinding fineness of -200 mesh accounting for 80%;

[0047] 3. Pre-adding sodium sulfide activator to the grinding slurry, stirring and reacting for ≥5 minutes to obtain slurry I;

[0048] 4. Add copper sulfate activator to the obtained slurry I again, and stir the reaction for ≥6 minutes to obtain slurry II;

[0049] 5. Add composite reagents to the ore pulp II and carry out two roughing selections, one fine selection and one scavenging selection to obtain zinc oxide concentrate.

[0050] For example: according to the process pre-selection, 1500g / t of sodium sulfide, 100g / t of copper sulfate, and 50g / t of composite collector (used as raw solution) are used. The specific usage amount needs to be adjusted based on the mutual content of lead and zinc in the sulfide tailings.

[0051] The feed content of the closed-circuit test of positive flotation of oxide ore was 1.55% Zn, the obtained zinc oxide concentrate contained 18.05% Zn, and the Zn recovery rate was 71.80%.

[0052] The first comparison

[0053] The same batch of low-grade zinc oxide ore as in the first embodiment is used for flotation.

[0054] This comparative example uses the traditional sulfide-xanthate method to study the effect of different flotation methods on the final zinc recovery rate of low-grade zinc oxide ore:

[0055] Experimental procedures;

[0056] 1. Use sodium sulfide as activator and butyl xanthate or amyl xanthate as collector;

[0057] 2. Grinding low-grade zinc oxide ore to obtain grinding slurry; the grinding slurry has a grinding fineness of -200 mesh accounting for 80%;

[0058] 3. Add sodium sulfide activator to the grinding slurry, and stir the reaction for ≥5 minutes to obtain slurry I;

[0059] 4. Add butyric acid to the ore pulp I, and carry out two roughing selections, one fine selection and one scavenging selection to obtain zinc oxide concentrate.

[0060] For example: according to the process, add 2500g / t of sodium sulfide and 250g / t of xanthate. The specific usage needs to be adjusted based on the mutual content of lead and zinc in the sulfide tailings.

[0061] The feed content of the closed-circuit test of oxide ore positive flotation was 1.57% Zn, the obtained zinc oxide concentrate contained 16.21% Zn, and the Zn recovery rate was 67.42%.

[0062] The second comparison

[0063] The same batch of low-grade zinc oxide ore as in the first embodiment is used for flotation.

[0064] This comparative example uses reverse flotation to study the effects of different flotation methods on the final zinc recovery rate of low-grade zinc oxide ore:

[0065] Experimental procedures;

[0066] 1. Use sodium sulfide as activator and modified oleic acid as collector;

[0067] 2. Grinding low-grade zinc oxide ore to obtain grinding slurry; the grinding slurry has a grinding fineness of -200 mesh accounting for 80%;

[0068] 3. Add sodium sulfide activator to the grinding slurry, and stir the reaction for ≥5 minutes to obtain slurry I;

[0069] 4. Add modified oleic acid to the ore pulp I and perform “two roughing and one sweeping” to obtain zinc oxide concentrate.

[0070] For example: according to the process, add 2800g / t of sodium sulfide and 100g / t of modified oleic acid. The specific usage needs to be adjusted based on the mutual content of lead and zinc in the sulfide tailings.

[0071] The feed ore of the closed-circuit test of reverse flotation of oxide ore contained 1.55% Zn, the obtained zinc oxide concentrate contained 16.58% Zn, and the Zn recovery rate was 68.25%.

[0072]

[0073] Judging from the test results, compared with the traditional xanthate sulfide flotation method and reverse flotation method, the low-grade zinc oxide ore activation capture flotation method is not only green and environmentally friendly, but also can improve the zinc grade of the concentrate, further improve the recovery rate of lead and zinc in low-grade zinc oxide ore, greatly reduce the amount of reagents used, and effectively solve the problems of reverse flotation foam viscosity and environmental risks.

[0074] It should be noted that, although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0075] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A low-grade zinc oxide ore activation capture flotation method, characterized in that: The method comprises the following steps: S1, grinding low-grade zinc oxide ore to obtain grinding slurry, wherein the grinding slurry has a grinding fineness of -200 mesh accounting for 80%; S2, adding sodium sulfide activator to the grinding slurry, stirring to obtain slurry I; S3, adding copper sulfate activator to the slurry I again, and stirring to obtain slurry II; S4, after adding composite reagents to the ore pulp II for collection, it is subjected to two roughing selections, one fine selection and one scavenging selection to obtain zinc oxide concentrate, wherein the composite reagents include fatty acid, palmitic acid and lauric acid.

2. The method according to claim 1, characterized in that the low-grade zinc oxide ore comprises: Hemimorphite, smithsonite, sphalerite.

3. The method according to claim 2, characterized in that the low-grade zinc oxide ore further comprises gangue minerals, and the gangue minerals comprise: Calcite, dolomite.

4. The method according to claim 3, characterized in that the zinc content in the low-grade zinc oxide ore is ≤2%.

5. The method according to claim 1, characterized in that the stirring time in S1 is ≥5 min.

6. as claimed in claim 1, characterized in that, the stirring time in S2 is ≥ 6min.

7. The method according to claim 1, wherein the amount ratio of the sodium sulfide activator to the copper sulfate activator is 15:

1.

8. The method according to claim 7, wherein the sodium sulfide activator is in an amount of 1500 g / t and the copper sulfate activator is in an amount of 100 g / t.

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