Copper-iron mineral flotation depressants and methods for their preparation

Abstract

The application provides a copper-iron mineral flotation inhibitor and a preparation method thereof, which comprises the following steps: adding water, o-aminobenzoic acid and hydrochloric acid into a reaction kettle, controlling the temperature in the reaction kettle to be 2-6 DEG C; adding sodium nitrite and sodium sulfite solution into the reaction kettle in sequence to carry out reaction; after the reaction is completed, the temperature in the reaction kettle is increased to 120-180 DEG C to continue the reaction for a predetermined time; after the reaction is completed, the temperature in the reaction kettle is decreased to 40-60 DEG C, tannic acid is added to carry out reaction, and finally the temperature is cooled to normal temperature, so the copper-iron mineral flotation inhibitor is obtained. The copper-iron mineral flotation inhibitor prepared by the application can be used as the inhibitor of copper-iron minerals in molybdenum ore and copper-molybdenum ore flotation, can effectively inhibit the copper sulfide mineral and the iron sulfide mineral, has the characteristics of small dosage and high efficiency of molybdenum mineral flotation under low alkalinity condition, and is convenient to control, has no by-product in the preparation process, and will not cause environmental pollution in production.

Description

Technical Field

[0001] This invention relates to the field of mineral flotation technology, and in particular to a flotation inhibitor for copper and iron minerals and its preparation method. Background Technology

[0002] In the flotation process of molybdenum ore, iron sulfide and copper sulfide minerals are crucial factors restricting the quality of molybdenum concentrate and flotation recovery indicators. To obtain qualified molybdenum concentrate products, lime and sodium sulfide / sodium hydrosulfide are generally used as depressants for pyrite and copper sulfide minerals, respectively, in flotation production. However, both types of reagents have significant drawbacks. Adding a large amount of lime to increase the pH of the flotation pulp, although achieving efficient inhibition of pyrite in a strongly alkaline flotation environment, significantly reduces the flotation recovery rate of molybdenum. While adding sodium sulfide / sodium hydrosulfide can achieve efficient inhibition of copper sulfide minerals, it suffers from drawbacks such as large reagent dosage, low separation efficiency, and harsh operating environment. Therefore, developing environmentally friendly and efficient copper-iron flotation depressants that can effectively inhibit both pyrite and copper sulfide minerals under low alkalinity conditions is key to solving the above problems.

[0003] In view of this, it is necessary to design an improved flotation inhibitor for copper and iron minerals and its preparation method to solve the above problems. Summary of the Invention

[0004] To address the shortcomings of the existing technology, the present invention aims to provide a copper-iron mineral flotation inhibitor and its preparation method, thereby achieving efficient separation of high-sulfur polymetallic ores.

[0005] To achieve the above objectives, this invention provides a method for preparing a flotation depressant for copper-iron minerals. The method includes the following steps: S1. Add water, o-aminobenzoic acid and hydrochloric acid to the reactor, and control the temperature inside the reactor to 2~6℃; S2. Add a sodium nitrite solution of a predetermined concentration to the reaction vessel and react for a predetermined time. S3. Add a sodium sulfite solution of a predetermined concentration to the reaction vessel and continue the reaction for a predetermined time. S4. Raise the temperature inside the reactor to 120~180℃ and continue the reaction; S5. Reduce the temperature inside the reactor to 40~60℃, add tannic acid to react, and after the reaction is complete, cool to room temperature to obtain a copper-iron mineral flotation inhibitor.

[0006] As a further improvement of the present invention, in step S1, the mass ratio of water, o-aminobenzoic acid and hydrochloric acid is (1.5~2.5):(1.0~1.2):(0.8~1.2).

[0007] As a further improvement of the present invention, in step S2, the predetermined concentration of the sodium nitrite solution is 20-40%, and the predetermined reaction time is 0.5-1h.

[0008] Furthermore, the mass ratio of the sodium nitrite solution to the hydrochloric acid in step S1 is (1.8~2.2):1.

[0009] As a further improvement of the present invention, in step S3, the predetermined concentration of the sodium sulfite solution is 40-45%, and the predetermined reaction time is 1-2 hours.

[0010] Furthermore, the mass ratio of the sodium sulfite solution to the hydrochloric acid in step S1 is (9~11):1.

[0011] As a further improvement of the present invention, in step S4, the predetermined reaction time is 1 to 2 hours.

[0012] As a further improvement of the present invention, in step S5, the mass ratio of the tannic acid to the hydrochloric acid in step S1 is (1~3):1; and the reaction time is 0.5~2h.

[0013] The present invention also provides a copper-iron mineral flotation inhibitor, which is prepared by the above-mentioned method for preparing copper-iron mineral flotation inhibitors.

[0014] The beneficial effects of this invention are: (1) This invention provides a copper-iron mineral flotation inhibitor and its preparation method. Water, o-aminobenzoic acid, and hydrochloric acid are added to a reaction vessel to control the reaction vessel temperature. Sodium nitrite solutions of different concentrations are added sequentially to the reaction vessel for reaction. After the reaction is complete, the temperature inside the reaction vessel is raised to 120-180°C for a predetermined reaction time, then cooled to 40-60°C, and tannic acid is added for further reaction. Finally, the mixture is cooled to room temperature to obtain the copper-iron mineral flotation inhibitor. The copper-iron mineral flotation inhibitor prepared by this invention can be used as an inhibitor for copper-iron minerals in the flotation of molybdenum ore and copper-molybdenum ore. It effectively inhibits both copper sulfide minerals and iron sulfide minerals, and can effectively improve the efficiency of copper-molybdenum separation and iron-sulfur separation.

[0015] (2) The copper-iron mineral flotation inhibitor prepared by the present invention has the advantages of low dosage, no need for further adjustment of pulp potential and pH value, and no generation of harmful gases during use. It overcomes the disadvantages of conventional inhibitors such as sodium sulfide / sodium hydrosulfide, which have harsh operating environment, large dosage and low efficiency.

[0016] (3) The copper-iron mineral flotation inhibitor prepared by the present invention is easy to produce and control, has no by-products during the preparation process, and will not cause pollution to the environment during production. Attached Figure Description

[0017] Figure 1 A flowchart of the flotation test for the copper-iron mineral flotation inhibitor prepared in Example 1 of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0020] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0021] This invention provides a method for preparing a flotation inhibitor for copper-iron minerals, comprising the following steps: S1. Add water, o-aminobenzoic acid and hydrochloric acid to the reactor, and control the temperature inside the reactor to 2~6℃.

[0022] Specifically, the preferred mass ratio of water, o-aminobenzoic acid, and hydrochloric acid is (1.5~2.5):(1.0~1.2):(0.8~1.2).

[0023] S2. Add a sodium nitrite solution of a predetermined concentration to the reaction vessel and react for a predetermined time.

[0024] Specifically, a sodium nitrite solution with a mass concentration of 20-40% is added to the reaction vessel and reacted for 0.5-1 hour. The preferred mass ratio of sodium nitrite solution to hydrochloric acid in step S1 is (1.8-2.2):1.

[0025] S3. Add a sodium sulfite solution of a predetermined concentration to the reaction vessel and continue the reaction for a predetermined time.

[0026] Specifically, after the reaction in step S2 is completed, a sodium sulfite solution with a mass concentration of 40-45% is added to the reaction vessel and the reaction is carried out for 1-2 hours. The preferred mass ratio of sodium sulfite solution to hydrochloric acid in step S1 is (9-11):1.

[0027] S4. Raise the temperature inside the reactor to 120~180℃ and continue the reaction.

[0028] Specifically, after the reaction in step S3 is completed, the temperature inside the reactor is raised to 120~180℃ and the reaction is carried out for 1~2 hours.

[0029] S5. Reduce the temperature inside the reactor to 40~60℃, add tannic acid to react, and after the reaction is complete, cool to room temperature to obtain a copper-iron mineral flotation inhibitor.

[0030] Specifically, the preferred mass ratio of tannic acid to hydrochloric acid in step S1 is (1~3):1, the reaction time is 0.5~2h, and the liquid obtained after cooling to room temperature is the copper-iron mineral flotation inhibitor.

[0031] The copper-iron mineral flotation inhibitor prepared by this invention is suitable for the flotation of high-sulfur and high-molybdenum ores. For ores with a sulfur grade of 2-8% and a molybdenum grade of >0.03%, the inhibitor of this invention can effectively inhibit both copper sulfide minerals and iron sulfide minerals, and can effectively improve the efficiency of copper-molybdenum separation and iron-sulfur separation.

[0032] The copper-iron mineral flotation inhibitor prepared by the above method was used for molybdenum ore flotation. The flotation process steps and conditions were as follows: S1. Add -2mm molybdenum ore to a ball mill and grind until the ore content of -0.074mm is 70~75%, and adjust the slurry mass concentration to 30%~35%; S2. Perform one roughing and three scavenging processes sequentially; the dosage of the roughing depressant is 180~200g / t, the dosage of kerosene is 40~50g / t, and the dosage of No. 2 oil is 20~30g / t; the dosage of the depressant for scavenging processes 1, 2, and 3 is 100~120g / t, 60~70g / t, and 30~40g / t, respectively; the dosage of kerosene is 20~30g / t, 10~20g / t, and 5~10g / t, respectively; and the dosage of No. 2 oil is 10~20g / t, 5~10g / t, and 5~10g / t, respectively. S3. After the rough concentrate is regrinded in a ball mill to a -0.045mm content of 80%~85%, it enters the fine cleaning operation. The dosage of inhibitor in fine cleaning 1 is 100~120g / t, and the dosage of kerosene is 5~10g / t; the dosage of inhibitor in fine cleaning 2~5 is 50~60g / t, 30~40g / t, 20~30g / t, and 10~20g / t, respectively. The concentrate of the 5th fine cleaning is molybdenum concentrate.

[0033] S4. The middlings produced by each sorting and scavenging operation are returned sequentially to the previous operation to form a closed loop.

[0034] To more clearly demonstrate the preparation method and application effects provided by this invention, the preparation method of the copper-iron mineral flotation inhibitor provided by this invention will be described below with reference to specific embodiments.

[0035] Example 1 This embodiment takes a high-sulfur molybdenum ore as the research object. The molybdenum grade in the ore is 0.158%, the copper grade is 0.035%, the molybdenum sulfide content is 94.22%, and the molybdenum oxide content is 5.78%. The mineral composition and content of the ore are shown in Table 1.

[0036] Table 1 Results of mineral composition and content analysis of ore The preparation method of copper-iron mineral flotation depressant includes the following steps: S1. First, weigh 120g of water, 60g of o-aminobenzoic acid and 60g of concentrated hydrochloric acid and add them to a small reaction vessel, and control the temperature inside the reaction vessel to 5℃. S2. Add 120g of 25% sodium nitrite solution to the reactor and react for 0.5h; S3. After the reaction in step S2 is completed, add 600g of sodium sulfite solution with a mass concentration of 42.5% to the reaction vessel and react for 1 hour; S4. After the reaction in step S3 is completed, raise the temperature inside the reactor to 120°C and react for 1 hour; S5. After the reaction in step S4 is completed, the temperature inside the reactor is reduced to 50°C, 120g of tannic acid is added to the reactor, the reaction is carried out for 1 hour, and the liquid obtained after cooling to room temperature is the copper-iron mineral flotation inhibitor.

[0037] The obtained products are categorized as follows: Figure 1 The flotation test was conducted using the process shown. The flotation process steps are as follows: S1. Add -2mm molybdenum ore to a ball mill and grind until the ore content of -0.074mm is 70%, then adjust the slurry concentration to 30%. S2. Perform one roughing and three scavenging processes sequentially; the dosage of the roughing depressant is 200 g / t, the dosage of kerosene is 40 g / t, and the dosage of No. 2 oil is 20 g / t; the dosages of the depressant for scavenging processes 1, 2, and 3 are 100 g / t, 60 g / t, and 30 g / t, respectively, the dosages of kerosene are 20 g / t, 10 g / t, and 5 g / t, respectively, and the dosages of No. 2 oil are 10 g / t, 5 g / t, and 5 g / t, respectively. S3. After the rough concentrate is regrinded in a ball mill to a content of 80% in -0.045mm, it enters the fine cleaning operation. The amount of inhibitor used in fine cleaning 1 is 100g / t, and the amount of kerosene used is 5g / t. The amounts of inhibitor used in fine cleaning 2 to fine cleaning 5 are 50g / t, 30g / t, 20g / t, and 10g / t, respectively. The concentrate of the 5th fine cleaning is molybdenum concentrate.

[0038] S4. The middlings produced by each sorting and scavenging operation are returned sequentially to the previous operation to form a closed loop.

[0039] The test results are shown in Table 2.

[0040] Table 2. Flotation test results using copper-iron mineral flotation depressants. As shown in Table 2, when the copper-iron mineral flotation inhibitor prepared by this invention is used for the flotation of molybdenum ore, a molybdenum concentrate with a grade of 45.42% and a copper content of 1.35% can be obtained under the condition of a total dosage of 600 g / t, and the molybdenum flotation recovery rate is 90.00%.

[0041] Comparative Example 1 Comparative Example 1 used the same molybdenum ore as Example 1, and the flotation test process and reagent dosage were the same. The only difference was that Comparative Example 1 used sodium hydrosulfide as an inhibitor. The test results are shown in Table 3.

[0042] Table 3. Flotation test results using sodium hydrosulfide as an inhibitor Table 3 shows that using sodium hydrosulfide as an inhibitor, the molybdenum concentrate grade was 30.85%, and the copper content in the molybdenum concentrate was 2.06%. The experimental results indicate that, under the same reagent dosage, sodium hydrosulfide's inhibitory effect was poor, mainly because the ore contained a high amount of pyrite, and sodium hydrosulfide's inhibitory effect on pyrite was weak, resulting in a lower molybdenum grade in the molybdenum concentrate.

[0043] Comparative Example 2 Comparative Example 2 used the same molybdenum ore as Example 1 as the research object. The flotation test process structure and kerosene usage were the same. The difference was that Comparative Example 2 used sodium hydrosulfide as an inhibitor, and 2 kg of lime was added as an inhibitor for pyrite in the roughing process. The test results are shown in Table 4.

[0044] Table 4. Experimental results using sodium hydrosulfide as an inhibitor. Table 4 shows that using sodium hydrosulfide and lime as depressants for pyrite and copper sulfide minerals resulted in a molybdenum grade of 46.89% and a copper content of 1.42% in the molybdenum concentrate. The combined use of lime and sodium hydrosulfide significantly increased the molybdenum grade in the concentrate, mainly due to the effective inhibition of pyrite by lime. However, the addition of lime in the process significantly increased the pH of the pulp, affecting the molybdenum flotation recovery and reducing the molybdenum recovery rate to 84.86%.

[0045] A comparison of the experimental results of Example 1 and Comparative Examples 1-2 shows that the copper-iron mineral flotation depressant prepared by the method of this invention, at a dosage of 600 g / t, can achieve highly efficient inhibition of copper sulfide and iron sulfide minerals without adjusting the pulp pH, resulting in ideal molybdenum concentrate and flotation recovery indicators. In contrast, using sodium hydrosulfide alone as a depressant fails to inhibit pyrite, leading to lower molybdenum concentrate grades. Furthermore, while using lime and sodium hydrosulfide as a combined depressant can yield a better quality molybdenum concentrate, the molybdenum recovery rate is significantly affected. Because the depressant prepared by this invention is an organic compound, it is stable and not easily oxidized, while sodium hydrosulfide is easily oxidized and degraded, resulting in a larger addition amount to achieve a certain effect. Therefore, the reagent of this invention has an ideal effect on copper sulfide and iron sulfide minerals, achieving precise separation of high-sulfur molybdenum ores with relatively small dosages. The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. 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 be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a flotation depressant for copper-iron minerals, characterized in that, Includes the following steps: S1. Add water, o-aminobenzoic acid and hydrochloric acid to the reaction vessel, and control the temperature inside the reaction vessel to 2-6℃; S2. Add a sodium nitrite solution of a predetermined concentration to the reaction vessel and react for a predetermined time. S3. Add a sodium sulfite solution of a predetermined concentration to the reaction vessel and continue the reaction for a predetermined time. S4. Raise the temperature inside the reactor to 120-180°C and continue the reaction; S5. Reduce the temperature inside the reactor to 40-60°C, add tannic acid to react, and after the reaction is complete, cool to room temperature to obtain a copper-iron mineral flotation inhibitor.

2. The method for preparing the copper-iron mineral flotation depressant according to claim 1, characterized in that, In step S1, the mass ratio of water, o-aminobenzoic acid and hydrochloric acid is (1.5-2.5):(1.0-1.2):(0.8-1.2).

3. The method for preparing the copper-iron mineral flotation inhibitor according to claim 1, characterized in that, In step S2, the predetermined concentration of the sodium nitrite solution is 20-40%, and the predetermined reaction time is 0.5-1 h.

4. The method for preparing the copper-iron mineral flotation inhibitor according to claim 3, characterized in that, The mass ratio of the sodium nitrite solution to the hydrochloric acid in step S1 is (1.8-2.2):

1.

5. The method for preparing the copper-iron mineral flotation depressant according to claim 1, characterized in that, In step S3, the predetermined concentration of the sodium sulfite solution is 40-45%.

6. The method for preparing the copper-iron mineral flotation inhibitor according to claim 5, characterized in that, The mass ratio of the sodium sulfite solution to the hydrochloric acid in step S1 is (9-11):

1.

7. The method for preparing the copper-iron mineral flotation inhibitor according to claim 1, characterized in that, In step S3, the reaction time is 1 to 2 hours.

8. The method for preparing the copper-iron mineral flotation depressant according to claim 1, characterized in that, In step S4, the reaction time is 1 to 2 hours.

9. The method for preparing the copper-iron mineral flotation depressant according to claim 1, characterized in that, In step S5, the mass ratio of the tannic acid to the hydrochloric acid in step S1 is (1-3):1; the reaction time is 0.5-2 hours.

10. A flotation depressant for copper and iron minerals, characterized in that, The copper-iron mineral flotation inhibitor is prepared by the method described in any one of claims 1-9.

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