Combined inhibitor for magnetite in flotation desulfurization of iron ore concentrate and use method of combined inhibitor

Abstract

The invention introduces a combined inhibitor for magnetite in flotation desulfurization of iron ore concentrate and a use method, the combined inhibitor is composed of ammonium sulfate, ammonium citrate and sodium humate, the synergistic effect of ammonium sulfate, ammonium citrate and sodium humate is exerted, the floatability and mechanical inclusion behavior of magnetite in the flotation desulfurization process are reduced, and the magnetite flotation desulfurization efficiency is improved. The recovery rate of the low-sulfur iron ore concentrate is increased while the iron ore concentrate desulfurization effect is achieved, and the comprehensive utilization rate of iron-sulfur resources is increased; a combined inhibitor is used, the flotation process of one-time roughing, two-time scavenging and one-time concentration is adopted, and the S content lt of the iron ore concentrate can be obtained for the iron ore concentrate with the S content being 1.0%-4.0%; 0.45%, the TFe recovery rate is gt; and the problems of separation, impurity reduction and comprehensive recovery of iron and sulfur in the iron ore concentrate are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of mineral processing, in particular to a combined inhibitor of magnetite in the flotation desulfurization of iron ore concentrate and a method for using the same. Background Art

[0002] Sulfur is a harmful impurity element in iron ore concentrate. Excessive sulfur content in iron ore concentrate will reduce the ductility, toughness and corrosiveness of steel, and sulfur emissions during the smelting process will also cause environmental pollution. Therefore, the steel industry has strict requirements on the sulfur impurity content in the iron ore entering the furnace. Iron ore concentrate mainly comes from magnetic separation process, and the sulfur in iron ore concentrate is mainly in the form of pyrrhotite. Due to the magnetic properties of pyrrhotite, it is difficult to separate it from the iron ore concentrate, namely magnetite, by magnetic separation. In production practice, flotation is generally used to remove sulfur from high-sulfur iron ore concentrate to meet the quality requirements of iron ore concentrate.

[0003] At present, for high-sulfur iron concentrates that do not meet quality requirements, flotation processes are mostly used for deep desulfurization at home and abroad. Research hotspots are mainly focused on activators and collectors for pyrrhotite. Patent CN 105363564 A discloses a desulfurization agent for flotation removal of pyrrhotite from high-sulfur iron concentrates. This agent mixes citric acid, tartaric acid, oxalic acid and copper sulfate as a pyrrhotite activator. Patent CN 115921126 A discloses an environmentally friendly desulfurization method from high-sulfur magnetic iron concentrates. This method combines solid copper sulfate and solid ferrous sulfate as a solid activator for pyrrhotite, which is used for flotation removal of pyrrhotite from iron concentrates. Patent CN 111495601 A disclosed a combined collector and method for removing pyrite and pyrrhotite from high-sulfur iron concentrate. The combined collector is composed of high-grade xanthate and hydroxamic acid and is used to remove pyrite and pyrrhotite from high-sulfur iron concentrate. These newly developed activators and collectors have achieved good desulfurization effects. However, the loss of iron concentrate during flotation desulfurization is also large, and the recovery rate is often less than 90%, resulting in a serious waste of iron resources. Therefore, while ensuring the flotation desulfurization effect of iron concentrate, it is particularly urgent to develop an inhibitor and treatment method that can effectively inhibit the flotation of magnetite and reduce the effect of mechanical inclusions. This is of great significance for improving the quality and recovery rate of iron concentrate, improving the utilization rate of mineral resources, and improving the economic benefits of mining enterprises. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a combined inhibitor of magnetite in the flotation desulfurization of iron ore concentrate and a method for using the same, which effectively reduces the flotation and mechanical inclusion behavior of magnetite, thereby improving the iron recovery rate in the flotation desulfurization process of iron ore concentrate and reducing iron metal loss.

[0005] The technical solution adopted in the present invention is: A combined inhibitor for magnetite in the flotation desulfurization of iron ore concentrate comprises ammonium sulfate, ammonium citrate and sodium humate in a mass ratio of 1:1:1 to 1:1:4.

[0006] Specifically, the combined inhibitor is used in an amount of 400-1000 g / t based on the dry weight of the magnetically separated sulfur-containing iron concentrate.

[0007] A method for using a combined inhibitor of magnetite in flotation desulfurization of iron ore concentrate, comprising the following steps: S1. Slurry preparation: According to the dry weight of the magnetically separated sulfur-containing iron concentrate, the iron concentrate is mixed with water for slurry preparation, and the slurry concentration is 25-35%; S2, desulfurization roughing operation: Add a combined inhibitor to the sulfur-containing iron concentrate slurry, stir, and then add activator copper sulfate, collector butyl xanthate and foaming agent No. 2 oil in sequence; after adding the drugs and adjusting the slurry, aerate and perform desulfurization roughing operation. The roughing tailings enter the desulfurization sweeping operation, and the roughing concentrate enters the floating sulfur concentration operation; S3, desulfurization sweeping operation: Scavenging and separation process 1: Add combined depressant to the roughing tailings slurry, stir, and then add activator copper sulfate, collector butyl xanthate, and foaming agent No. 2 oil in sequence; after adding the chemicals and adjusting the slurry, aerate and carry out scavenging and separation process 1. The scavenging and separation tailings enter the scavenging and separation process 2, and the scavenging and separation concentrate enters the floating sulfur concentration process; Second scavenging operation: Add a combined inhibitor to the slurry of the scavenging tailings from the first scavenging operation, stir, and then add the activator copper sulfate, the collector butyl xanthate, and the foaming agent No. 2 oil in sequence; after adding the drugs and adjusting the slurry, aerate and proceed to the second scavenging operation. The tailings from the second scavenging operation are low-sulfur iron concentrate, and the concentrate from the second scavenging operation enters the floating sulfur concentration operation; S4, floating sulfur concentration operation: the roughing concentrate of S2 and the scavenging concentrate 1 and scavenging concentrate 2 in S3 are combined to form a mixed concentrate, and a combined inhibitor is added to the mixed concentrate; after adding chemicals and slurry adjustment, aeration is carried out for sulfur concentration operation, and the selected tailings are returned to the roughing operation. The selected concentrate is sulfur concentrate.

[0008] Specifically, in the S2-S4, based on the dry weight of the sulfur-containing magnetic iron concentrate, the dosage of the combined inhibitor is as follows: 200-600 g / t for the desulfurization roughing operation; 100-200 g / t for the first scavenging operation of the desulfurization scavenging operation, 50-100 g / t for the second scavenging operation; and 50-100 g / t for the floating sulfur concentration operation.

[0009] Specifically, in the S2 and S3, based on the dry weight of the magnetically separated sulfur-containing iron concentrate, the amount of copper sulfate used is as follows: 100-200 g / t for the desulfurization roughing operation, 50-100 g / t for the first scavenging operation of the desulfurization scavenging operation, and 25-50 g / t for the second scavenging operation.

[0010] Specifically, in the S2 and S3, based on the dry weight of the magnetically separated sulfur-containing iron concentrate, the dosage of butyl xanthate is as follows: 200-300 g / t for the desulfurization roughing operation, 100-150 g / t for the first scavenging operation of the desulfurization scavenging operation, and 50-75 g / t for the second scavenging operation.

[0011] Specifically, in the aforementioned S2 and S3, based on the dry weight of the magnetically separated sulfur-containing iron concentrate, the usage of No. 2 oil is as follows: 40 g / t for the desulfurization roughing operation, 20 g / t for the first scavenging operation of the desulfurization scavenging operation, and 10 g / t for the second scavenging operation.

[0012] Due to the adoption of the above technical solution, the present invention has the following advantages: 1. The combined inhibitor of the present invention is simple to produce and easy to operate, requires little reagent, and is safe and reliable; 2. The combined inhibitor of the present invention can selectively inhibit magnetite without inhibiting pyrrhotite. The combined inhibitor is co-adsorbed on the surface of magnetite, exerting a synergistic effect, enhancing the inhibitory ability, effectively improving the grade and recovery rate of iron ore concentrate during the desulfurization process, and improving flotation efficiency. 3. The combined inhibitor of the present invention can adjust the surface electrical properties of the minerals and the ionic strength of the pulp, reducing the floatation of magnetite and the mechanical inclusion behavior between minerals during flotation desulfurization, which helps to further improve the recovery rate of iron ore concentrate and flotation efficiency during the desulfurization process; 4. The magnetite combination inhibitor of the present invention is used for flotation desulfurization of high-sulfur iron concentrate. Different dosages are used according to different operations in desulfurization roughing, desulfurization scavenging and flotation sulfur concentration. Compared with no inhibitor addition, the recovery rate of iron concentrate is effectively increased by more than five percentage points, thereby improving the comprehensive utilization rate of iron and sulfur resources. 5. The combined depressant and "one coarse, two scavengers, and one fine" flotation process of the present invention can achieve excellent indicators of iron concentrate S content <0.45% and TFe recovery rate >92.00% for iron concentrate with a S content of 1.0% to 4.0%, solving the problems of iron and sulfur separation, impurity reduction, and comprehensive recovery in iron concentrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall process of the present invention. DETAILED DESCRIPTION

[0014] The present invention will be further explained below with reference to the accompanying drawings and embodiments, which should not be used to limit the scope of protection of the present invention. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention. Example 1

[0015] Taking a high-sulfur magnetic iron concentrate with an iron grade of 59.76% and a sulfur content of up to 3.72% as an example, in order to obtain qualified iron concentrate that meets market requirements, a combined inhibitor of magnetite in the flotation desulfurization of iron concentrate is used, including ammonium sulfate, ammonium citrate and sodium humate in a mass ratio of 1:1:4.

[0016] Combined with attachment Figure 1 The method for using a combined inhibitor of magnetite in flotation desulfurization of iron ore is shown, and the specific steps are as follows: S1. Slurry preparation: According to the dry weight of the magnetically separated sulfur-containing iron concentrate, the iron concentrate is mixed with water for slurry preparation, and the slurry concentration is 30%; S2, desulfurization roughing operation: add a combined inhibitor to the sulfur-containing iron concentrate slurry at a rate of 600 g / t, stir for 5 minutes, add 200 g / t of copper sulfate, stir for 3 minutes, add 300 g / t of butyl xanthate, stir for 5 minutes, add 40 g / t of No. 2 oil, stir for 2 minutes, aerate for desulfurization roughing operation, flotation time 5 minutes, roughing tailings enter desulfurization sweeping operation, roughing concentrate enters flotation sulfur concentration operation; S3, desulfurization sweeping operation: Scavenging operation 1: add a combined inhibitor of 200g / t to the roughing tailings slurry, stir for 5 minutes, add 100g / t of copper sulfate, stir for 3 minutes, add 150g / t of butyl xanthate, stir for 5 minutes, add 20g / t of No. 2 oil, stir for 2 minutes, aerate and start scavenging operation 1. The flotation time is 3 minutes. The scavenging tailings from 1 enter the scavenging operation 2, and the scavenging concentrate enters the floating sulfur concentration operation. Scavenging and selection operation 2: add a combined inhibitor to the slurry of the scavenging and selection tailings at a rate of 100g / t, stir for 5 minutes, add 50g / t of copper sulfate, stir for 3 minutes, add 75g / t of butyl xanthate, stir for 5 minutes, add 10g / t of No. 2 oil, stir for 2 minutes, then aerate and proceed to scavenging and selection operation 2. The flotation time is 3 minutes. The scavenging and selection tailings 2 are low-sulfur iron concentrates, and the scavenging and selection concentrates 2 enter the flotation sulfur concentration operation. S4, floating sulfur concentration operation: the roughing concentrate of S2 and the scavenging concentrate 1 and scavenging concentrate 2 in S3 are combined to form a mixed concentrate, and 100g / t of combined depressant is added to the mixed concentrate; after stirring for 5 minutes, aeration is carried out for sulfur concentration operation, and the flotation time is 3 minutes. The selected tailings are returned to the roughing operation, and the selected concentrate is sulfur concentrate.

[0017] Table 1 shows the test results for Example 1 and Comparative Example 1, using the process of Example 1 of the present invention without adding the combined inhibitor in each step. As shown in Table 1, under comparable flotation desulfurization conditions, the use of a combined inhibitor of ammonium sulfate, ammonium citrate, and sodium humate significantly improved iron concentrate performance compared to that achieved without the addition of inhibitors. The addition of the combined inhibitor yielded a low-sulfur iron concentrate with a TFe grade of 62.44% and a recovery of 92.10%, representing a recovery 5.32 percentage points higher than that achieved without the addition of inhibitors.

[0018] Table 1 Test results of Example 1 and Comparative Example 1 Example 2

[0019] Taking a high-sulfur magnetic iron concentrate with an iron grade of 62.12% and a sulfur content of up to 2.38% as an example, in order to obtain qualified iron concentrate that meets market requirements, a combined inhibitor of magnetite in the flotation desulfurization of iron concentrate is used, including ammonium sulfate, ammonium citrate and sodium humate in a mass ratio of 1:1:2.

[0020] Combined with attachment Figure 1 The method for using a combined inhibitor of magnetite in flotation desulfurization of iron ore is shown, and the specific steps are as follows: S1. Slurry preparation: According to the dry weight of the magnetically separated sulfur-containing iron concentrate, the iron concentrate is mixed with water for slurry preparation, and the slurry concentration is 30%; S2, desulfurization roughing operation: add a combined inhibitor to the sulfur-containing iron concentrate slurry at a rate of 400g / t, stir for 5 minutes, add 150g / t of copper sulfate, stir for 3 minutes, add 300g / t of butyl xanthate, stir for 5 minutes, add 40g / t of No. 2 oil, stir for 2 minutes, aerate for desulfurization roughing operation, flotation time 5 minutes, roughing tailings enter desulfurization sweeping operation, roughing concentrate enters flotation sulfur concentration operation; S3, desulfurization sweeping operation: Scavenging operation 1: Add a combined inhibitor of 200g / t to the roughing tailings slurry, stir for 5 minutes, add 75g / t of copper sulfate, stir for 3 minutes, add 150g / t of butyl xanthate, stir for 5 minutes, add 20g / t of No. 2 oil, stir for 2 minutes, aerate and start scavenging operation 1. The flotation time is 3 minutes. The scavenging tailings from 1 enter the scavenging operation 2, and the scavenging concentrate enters the floating sulfur concentration operation. Scavenging and selection operation 2: add a combined inhibitor to the slurry of the scavenging and selection tailings at a rate of 100g / t, stir for 5 minutes, add 40g / t of copper sulfate, stir for 3 minutes, add 75g / t of butyl xanthate, stir for 5 minutes, add 10g / t of No. 2 oil, stir for 2 minutes, aerate and start scavenging and selection operation 2. The flotation time is 3 minutes. The scavenging and selection tailings 2 are low-sulfur iron concentrates. The scavenging and selection concentrates 2 enter the flotation sulfur concentration operation. S4, floating sulfur concentration operation: the roughing concentrate of S2 and the scavenging concentrate 1 and scavenging concentrate 2 in S3 are combined to form a mixed concentrate, and 80g / t of combined inhibitor is added to the mixed concentrate; after stirring for 5 minutes, aeration is carried out for sulfur concentration operation, and the flotation time is 3 minutes. The selected tailings are returned to the roughing operation, and the selected concentrate is sulfur concentrate.

[0021] Taking the process of Example 2 of the present invention as Comparative Example 2, no combined inhibitor was added in each step. The test results of Example 2 and Comparative Example 2 are shown in Table 2. As can be seen from Table 2, under conditions of equivalent flotation desulfurization effect, the use of the combined inhibitor of ammonium sulfate, ammonium citrate and sodium humate significantly improved the iron concentrate indicators compared to those without the addition of inhibitors. The addition of the combined inhibitor can obtain a low-sulfur iron concentrate with a TFe grade of 63.88% and a recovery rate of 95.37%, which is 5.55 percentage points higher than that without the addition of inhibitors.

[0022] Table 2 Test results of Example 2 and Comparative Example 2 Example 3

[0023] Taking a high-sulfur magnetic iron concentrate with an iron grade of 63.13% and a sulfur content of up to 1.39% as an example, in order to obtain qualified iron concentrate that meets market requirements, a combined inhibitor of magnetite in the flotation desulfurization of iron concentrate is used, including ammonium sulfate, ammonium citrate and sodium humate in a mass ratio of 1:1:1.

[0024] Combined with attachment Figure 1 The method for using a combined inhibitor of magnetite in flotation desulfurization of iron ore is shown, and the specific steps are as follows: S1. Slurry preparation: According to the dry weight of the magnetically separated sulfur-containing iron concentrate, the iron concentrate is mixed with water for slurry preparation, and the slurry concentration is 35%; S2, desulfurization roughing operation: add a combined inhibitor to the sulfur-containing iron concentrate slurry at a rate of 200g / t, stir for 5 minutes, add 100g / t of copper sulfate, stir for 3 minutes, add 200g / t of butyl xanthate, stir for 5 minutes, add 40g / t of No. 2 oil, stir for 2 minutes, aerate for desulfurization roughing operation, flotation time 5 minutes, roughing tailings enter desulfurization sweeping operation, roughing concentrate enters flotation sulfur concentration operation; S3, desulfurization sweeping operation: Scavenging operation 1: add a combined inhibitor to the roughing tailings slurry at a rate of 100g / t, stir for 5 minutes, add 50g / t of copper sulfate, stir for 3 minutes, add 100g / t of butyl xanthate, stir for 5 minutes, add 20g / t of No. 2 oil, stir for 2 minutes, then aerate for scavenging operation 1. The flotation time is 3 minutes. The scavenging tailings enter the scavenging operation 2, and the scavenging concentrate enters the floating sulfur concentration operation. Scavenging and selection operation 2: Add a combined inhibitor to the slurry of the scavenging and selection tailings at a rate of 50 g / t. After stirring for 5 minutes, add 25 g / t of copper sulfate. After stirring for 3 minutes, add 50 g / t of butyl xanthate. After stirring for 5 minutes, add 10 g / t of No. 2 oil. After stirring for 2 minutes, aerate and proceed to scavenging and selection operation 2. The flotation time is 3 minutes. The scavenging and selection tailings 2 are low-sulfur iron concentrates. The scavenging and selection concentrates 2 enter the flotation sulfur concentration operation. S4, floating sulfur concentration operation: the roughing concentrate of S2 and the scavenging concentrate 1 and scavenging concentrate 2 in S3 are combined to form a mixed concentrate, and 50g / t of combined inhibitor is added to the mixed concentrate; after stirring for 5 minutes, aeration is carried out for sulfur concentration operation, and the flotation time is 3 minutes. The selected tailings are returned to the roughing operation, and the selected concentrate is sulfur concentrate.

[0025] The process of Example 3 of the present invention is used, and no combined inhibitor is added in each step, which is Comparative Example 3. The test results of Example 3 and Comparative Example 3 are shown in Table 3. As can be seen from Table 3, under conditions of equivalent flotation desulfurization effect, the use of the combined inhibitor of ammonium sulfate, ammonium citrate, and sodium humate significantly improves the iron concentrate indicators compared to those without the addition of inhibitors. The addition of the combined inhibitor can obtain a low-sulfur iron concentrate with a TFe grade of 64.44% and a recovery rate of 97.36%, which is 5.01 percentage points higher than that without the addition of inhibitors.

[0026] Table 3 Test results of Example 3 and Comparative Example 3

[0027] The parts not described in detail in this invention are prior art.

[0028] The embodiments selected herein for the purpose of disclosing the invention are presently considered suitable, but it should be understood that the invention is intended to include all variations and modifications of the embodiments that fall within the scope of the concept and invention.

Claims

1. A combined inhibitor of magnetite in the flotation desulfurization of iron ore concentrate, characterized by: The invention comprises ammonium sulfate, ammonium citrate and sodium humate in a mass ratio of 1:1:1-1:1:

4.

2. The combined inhibitor of magnetite in the flotation desulfurization of iron ore concentrate according to claim 1, characterized in that: The combined inhibitor is used in an amount of 400-1000 g / t based on the dry weight of the magnetically separated sulfur-containing iron concentrate.

3. A method for using a combined inhibitor of magnetite in flotation desulfurization of iron ore according to any one of claims 1 or 2, characterized in that: The specific steps are: S1. Slurry preparation: According to the dry weight of the magnetically separated sulfur-containing iron concentrate, the iron concentrate is mixed with water for slurry preparation, and the slurry concentration is 25-35%; S2, desulfurization roughing operation: Add a combined inhibitor to the sulfur-containing iron concentrate slurry, stir, and then add activator copper sulfate, collector butyl xanthate and foaming agent No. 2 oil in sequence; after adding the drugs and adjusting the slurry, aerate and perform desulfurization roughing operation. The roughing tailings enter the desulfurization sweeping operation, and the roughing concentrate enters the floating sulfur concentration operation; S3, desulfurization sweeping operation: Scavenging and separation process 1: Add combined depressant to the roughing tailings slurry, stir, and then add activator copper sulfate, collector butyl xanthate, and foaming agent No. 2 oil in sequence; after adding the chemicals and adjusting the slurry, aerate and carry out scavenging and separation process 1. The scavenging and separation tailings enter the scavenging and separation process 2, and the scavenging and separation concentrate enters the floating sulfur concentration process; Second scavenging operation: Add a combined inhibitor to the slurry of the scavenging tailings from the first scavenging operation, stir, and then add the activator copper sulfate, the collector butyl xanthate, and the foaming agent No. 2 oil in sequence; after adding the drugs and adjusting the slurry, aerate and proceed to the second scavenging operation. The tailings from the second scavenging operation are low-sulfur iron concentrate, and the concentrate from the second scavenging operation enters the floating sulfur concentration operation; S4, floating sulfur concentration operation: the roughing concentrate of S2 and the scavenging concentrate 1 and scavenging concentrate 2 in S3 are combined to form a mixed concentrate, and a combined inhibitor is added to the mixed concentrate; after adding chemicals and slurry adjustment, aeration is carried out for sulfur concentration operation, and the selected tailings are returned to the roughing operation. The selected concentrate is sulfur concentrate.

4. The method for using a combined inhibitor of magnetite in flotation desulfurization of iron ore according to claim 3, characterized in that: In the above-mentioned S2-S4, based on the dry weight of the sulfur-containing magnetic iron concentrate, the dosage of the combined inhibitor is specifically as follows: 200-600 g / t for the desulfurization roughing operation; 100-200 g / t for the first scavenging operation of the desulfurization scavenging operation, 50-100 g / t for the second scavenging operation; and 50-100 g / t for the floating sulfur concentration operation.

5. The method for using the combined inhibitor of magnetite in the flotation desulfurization of iron ore concentrate according to claim 3, characterized in that: In the above-mentioned S2 and S3, based on the dry weight of the magnetically separated sulfur-containing iron concentrate, the specific amount of copper sulfate used is: 100-200 g / t for the desulfurization roughing operation, 50-100 g / t for the first scavenging operation of the desulfurization scavenging operation, and 25-50 g / t for the second scavenging operation.

6. The method for using a combined inhibitor of magnetite in flotation desulfurization of iron ore according to claim 3, characterized in that: In the above-mentioned S2 and S3, the dosage of butyl xanthate is specifically calculated according to the dry weight of the magnetically separated sulfur-containing iron concentrate: 200-300 g / t for the desulfurization roughing operation, 100-150 g / t for the first scavenging operation of the desulfurization scavenging operation, and 50-75 g / t for the second scavenging operation.

7. The method for using a combined inhibitor of magnetite in flotation desulfurization of iron ore according to claim 3, characterized in that: In the above-mentioned S2 and S3, based on the dry weight of the magnetically separated sulfur-containing iron concentrate, the specific amount of No. 2 oil used is: 40g / t for the desulfurization roughing operation, 20g / t for the first scavenging operation of the desulfurization scavenging operation, and 10g / t for the second scavenging operation.

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