Preparation method of pyrite flotation inhibitor and application thereof

Abstract

The application discloses a preparation method of a pyrite flotation inhibitor and application thereof, and belongs to the technical field of flotation inhibitors. A certain amount of fly ash and modified reagents are weighed and mixed, and then are placed in a grinding device for sufficient grinding. After grinding, the mixture is cooled to room temperature to obtain the pyrite flotation inhibitor. The preparation method of the pyrite flotation inhibitor and application thereof provided by the application innovatively modifies solid waste fly ash into a pyrite inhibitor. The modified fly ash can not only be adsorbed on the surface of pyrite under low-alkali conditions to prevent the adsorption of a collector, but also can be complexed with difficult-to-avoid metal ions (Cu 2+ , Pb 2+ , Zn 2+ , etc.) in ore pulp to shield the activation effect of the difficult-to-avoid ions on pyrite, and further reduce the floatability of pyrite.

Description

Technical Field

[0001] This invention relates to the field of flotation inhibitor technology, specifically to a method for preparing a pyrite flotation inhibitor and its application. Background Technology

[0002] Pyrite is the most widely distributed and common sulfide mineral in nature, and a major carrier mineral for precious metals (gold, silver, etc.) or rare metal resources. It is often associated with non-ferrous metal minerals such as chalcopyrite, sphalerite, and galena. Pyrite has a certain degree of floatability. In the flotation process of polymetallic sulfide minerals, pyrite tends to float up with the main metal and enter the concentrate product, reducing the recovery rate and grade of the concentrate product, affecting the economic benefits of enterprises, and adversely impacting subsequent smelting and other processes.

[0003] In industrial processes, to obtain qualified concentrate products, a large amount of lime is usually added during the flotation of the main metallic minerals to inhibit the floating of pyrite. Although the traditional high-alkali lime process can achieve good flotation indicators, it generally suffers from many problems such as easy scaling of equipment and slurry conveying pipelines, low comprehensive recovery rate of associated precious metals, and serious pollution of mineral processing wastewater.

[0004] Compared to inorganic depressants, organic depressants, which are abundant, biodegradable, and relatively inexpensive, are attracting significant attention. Commonly used organic depressants in pyrite flotation include sodium humate, starch, dextrin, guar gum, and polyacrylamide. These macromolecules possess numerous hydrophilic groups, exhibiting good inhibitory effects on sulfide gangues such as pyrite. However, their selectivity is insufficient, and in actual flotation, they lose their targeted inhibitory effect on pyrite. Therefore, when using macromolecular organic depressants, precise control of the dosage of both the depressant and collector is necessary, which is difficult to achieve in actual industrial production. Thus, developing environmentally friendly, efficient, and highly selective novel pyrite depressants to improve mineral resource separation efficiency and reduce the difficulty of separating polymetallic mineral resources is one of the major problems urgently needing to be solved in the current mineral resource industry. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing pyrite flotation inhibitors and their applications. By modifying fly ash, a solid waste, to give it an inhibitory effect, it inhibits the flotation of pyrite, thereby improving the separation efficiency of polymetallic sulfide ores, reducing the difficulty of mineral separation, and reducing production costs.

[0006] To achieve the above objectives, the present invention provides a method for preparing a pyrite flotation depressant, comprising the following steps:

[0007] S1. Weigh out a certain amount of fly ash and modifying agent;

[0008] S2. Mix fly ash and modifying agent, and grind them thoroughly in a grinding device;

[0009] S3. Allow to stand and cool to room temperature to obtain pyrite flotation inhibitor.

[0010] Preferably, the mass ratio of fly ash to modifying agent in step S1 is 1:(1-5).

[0011] Preferably, the fly ash used in step S1 is fine ash collected from the flue gas after coal combustion.

[0012] Preferably, the modifying agent used in step S1 is one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium sulfite, and potassium sulfite.

[0013] Preferably, the grinding time in step S2 is greater than 3 minutes, and the fineness of the resulting grinding mixture is less than 300 μm.

[0014] The pyrite flotation inhibitor prepared by the above method is used for the flotation of pyrite.

[0015] The pyrite flotation inhibitor prepared by the above method can be used in either pure solid or pure liquid form when applied to pyrite flotation.

[0016] Fly ash is a relatively stable porous honeycomb-like solid waste composed of oxides such as active SiO2 (glassy SiO2) and active Al2O3 (glassy Al2O3). Due to the porous structure of its bead walls, the porosity is as high as 50%-80%, resulting in a large specific surface area and strong adsorption performance. Moreover, due to its large surface negative charge, it can also undergo a series of reactions with heavy metal ions in water, adsorbing "inevitable ions". This allows free "inevitable ions" in the slurry to be adsorbed on the surface of the fly ash, thereby avoiding the activation effect of "inevitable ions" on pyrite and further enhancing the inhibitory effect on pyrite.

[0017] Therefore, this invention provides a method for preparing pyrite flotation depressant and its application, with the following beneficial effects:

[0018] (1) This invention is the first to use solid waste fly ash as a raw material, modifying it into a pyrite inhibitor. This modified fly ash, in addition to having a strong inhibitory effect on pyrite, can also react with metal ions (Cu) in minerals, slurries, and inorganic reagents. 2+ Pb 2+ Zn 2+ It complexes with pyrite, shielding it from the activation effect of "inevitable ions" on pyrite and reducing its floatability. Its inhibitory ability is particularly outstanding in the flotation of copper sulfide, lead, and zinc.

[0019] (2) Fly ash has high porosity and large specific surface area, and has high adsorption activity and strong water absorption. The specific surface area and porosity of the modified fly ash are further increased, which can be better adsorbed on the surface of pyrite, increasing its surface hydrophilicity. At the same time, it prevents the collector from adsorbing on the surface of pyrite, reducing the collector's collecting effect on pyrite. It effectively solves the problems of traditional inhibitors, such as difficulty in preparation, large dosage, toxicity, great environmental pollution, and large fluctuations in mineral processing production indicators.

[0020] (3) The pyrite inhibitor prepared by the present invention has stable chemical properties, high separation efficiency, is green and efficient, has low dosage, strong adaptability, low preparation cost, and stable and reliable preparation process. It can be widely used in the flotation separation of polymetallic sulfide ores.

[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the process flow of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the scope of the claimed invention, but rather represent selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0024] Example 1

[0025] This embodiment provides a method for preparing a pyrite flotation inhibitor. 50 parts of fly ash and 50 parts of sodium sulfite are weighed at a mass ratio of 1:1. The two are mixed and then fed into a stirred mill for thorough grinding. After grinding, the mixture is allowed to stand and cooled to room temperature. The resulting dark brown (black) powder is the pyrite inhibitor, denoted as reagent 1.

[0026] Example 2

[0027] This embodiment provides a method for preparing a pyrite flotation inhibitor. All other conditions are the same as in Example 1, except that the mass ratio of added fly ash and sodium sulfite is 1:5; the resulting product is referred to as Reagent 2.

[0028] Comparative Example 1

[0029] All other conditions in this comparative example are the same as in Example 1, except that no fly ash is added; the resulting product is referred to as Comparative Reagent 1.

[0030] Comparative Example 2

[0031] All other conditions in this comparative example are the same as in Example 1, except that sodium sulfite is not added; the resulting product is designated as Comparative Reagent 2.

[0032] Comparative Example 3

[0033] All other conditions in this comparative example are the same as in Example 1, except that the mass ratio of fly ash to sodium sulfite is 5:1; the resulting product is referred to as Comparative Reagent 3.

[0034] Comparative Example 4

[0035] All other conditions in this comparative example are the same as in Example 1, except that there is no grinding process after mixing; the resulting product is designated as Comparative Reagent 4.

[0036] Comparative Example 5

[0037] The inhibitor used in this comparative example was lime.

[0038] Comparative Example 6

[0039] The inhibitor used in this comparative example was sodium humate.

[0040] Comparative Example 7

[0041] The inhibitor used in this comparative example was sodium cyanide.

[0042] flotation test

[0043] 1. Ore raw materials

[0044] The ore raw material was taken from a copper sulfide mine in Jiangxi Province, containing about 5.3% copper, about 11.5% iron, and about 14.2% sulfur. Among them, the copper is mainly chalcopyrite and the iron is mainly pyrite. The inhibitors used in the experiment were Examples 1-2 and Comparative Examples 1-7, the collector used was butyl xanthate, and the foaming agent used was No. 2 oil.

[0045] 2. Operating procedures and technical conditions

[0046] Take 500g of raw dry ore, mix it with water at a 1:1 ratio, and grind it. Then transfer the slurry to a flotation machine, adjust the slurry concentration to 30-45%, and add 500g / t of depressant, 100g / t of collector, and 20g / t of frother sequentially. Stir each reagent for 3 minutes. After the reagents have fully acted, start a flotation operation consisting of one roughing, two cleaning, and two scavenging stages. The roughing concentrate enters the cleaning stage, and the roughing tailings enter the scavenging stage. The depressant dosage for the first cleaning stage is 300g / t. The first concentrate enters the second cleaning stage. After the second blank cleaning, the final concentrate is obtained, and the cleaning tailings are returned to the previous stage. The roughing tailings are scavenged twice to obtain the final tailings. The scavenging collector dosage is 20g / t. The experimental procedure is as follows: Figure 1 The experimental results are shown in Table 1.

[0047] Table 1

[0048]

[0049]

[0050] The experimental data in Table 1 show that the inhibitor prepared in this invention has a good inhibitory effect on pyrite and can significantly improve the quality of copper concentrate. Using the inhibitor prepared in this invention, high-quality copper concentrate with a copper grade of 25.83%, an iron grade of 32.77%, and a copper recovery rate of 90.82% can be obtained. This invention innovatively modifies solid waste fly ash into a pyrite inhibitor. Compared with traditional pyrite inhibitors (lime, sodium humate, sodium cyanide, etc.), this modified fly ash can not only adsorb onto the surface of pyrite under low-alkali conditions, preventing the adsorption of collectors, but also react with unavoidable metal ions (Cu) in the slurry. 2+ Pb 2+ Zn 2+ By complexing with pyrite (e.g., ions that are difficult to separate from other metal sulfide ores and shielding the activation effect of "inevitable ions") on pyrite, the floatability of pyrite is further reduced. This technical approach not only reduces the difficulty of separating pyrite from other metal sulfide ores and improves separation efficiency, but also saves reagent costs and improves the economic and social benefits of mining enterprises.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. Use of a pyrite flotation depressant in the flotation of pyrite, characterized in that, The preparation method of the pyrite flotation inhibitor comprises the following steps: S1, weighing a certain amount of fly ash and modified reagent; S2, mixing the fly ash and the modified reagent and placing them in a grinding device for sufficient grinding; S3, standing and cooling to room temperature to obtain the pyrite flotation inhibitor; The mass ratio of the fly ash to the modified reagent in the step S1 is 1:(1-5); The fly ash used in the step S1 is fine ash collected from flue gas after coal combustion; The modified reagent used in the step S1 is one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium sulfite and potassium sulfite.

2. Use according to claim 1, characterized in that: The grinding time in the step S2 is greater than 3 minutes, and the fineness of the obtained grinding mixture is less than 300 um.

3. Use according to claim 1, characterized in that: The inhibitor is used in the form of pure solid or pure liquid in the pyrite flotation.

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