Recycling method of desulfurization waste liquid in iron ore comprehensive beneficiation system

Abstract

The invention belongs to the field of mineral engineering beneficiation water cyclic utilization, and particularly relates to a cyclic utilization method of desulfurization waste liquid in an iron ore comprehensive beneficiation system, which comprises the following specific steps: S1, analyzing the influence degree of desulfurization waste liquid with different hardness on the beneficiation separation effect; s2, selecting the maximum hardness value which is smaller than or equal to the maximum hardness value which does not affect the mineral separation effect of the desulfurization waste liquid as a control standard when the desulfurization waste liquid enters a system; s3, connecting a bypass valve near an outlet of a concentrate water return pipeline of the original pelletizing system to ensure that the system can be switched to the tailing pond when the desulfurization waste liquid enters the system through the pipeline, and timely adjusting ore drawing branch pipes of the tailing pond to be an eighth group far away from the water return system when the desulfurization waste liquid enters the tailing pond to ensure that sufficient clarification distance is reserved, so as to achieve the aim of settling the desulfurization waste liquid. And when the hardness of the desulfurized waste liquid-containing tailing return water is smaller than or equal to the control standard concentration in S2, the mineral separation process requirements are met. According to the method, the desulfurization waste liquid is fully utilized, the flotation separation effect is not affected, independent water treatment is not needed, and the cost is reduced.

Description

Technical Field

[0001] The invention belongs to the field of recycling of mineral processing water in mining engineering, and in particular relates to a recycling method for desulfurization waste liquid in an iron ore comprehensive mineral processing system. Background Art

[0002] With the advancement of mining equipment, process technology and management level, the scale of mines is becoming larger and larger, especially new iron mines often have mining, mineral processing and pelletizing processes at the same time. In order to deal with the domestic "lean, fine and mixed" iron ore, its mineral processing technology is no longer a single magnetic separation or a simple magnetic and heavy combined separation. The flotation process using various new and efficient reagents has been widely used. The chemical reaction process of the flotation reagent has very strict requirements on the pH, hardness, conductivity, and various ion concentrations of the pulp. The desulfurization process of pellet production often adopts the lime / gypsum wet desulfurization process. The high-hardness and high-conductivity waste liquid generated by this process will destroy the chemical characteristics of the flotation pulp when recycled, which is easy to cause the flotation separation effect to deteriorate and the mineral processing production to fluctuate. However, due to its small amount and non-continuous discharge, it is costly and difficult to carry out water treatment alone. Summary of the invention

[0003] The purpose of the present invention is to provide a method for recycling desulfurization waste liquid in an iron ore comprehensive beneficiation system, so as to solve the problem that traditional waste liquid utilization will destroy the chemical properties of flotation pulp, easily lead to poor flotation separation effect and fluctuation of beneficiation production.

[0004] In order to achieve the above object, the present invention adopts the following technical scheme: The traditional way of mineral processing water circulation is: the tailings return water from the tailings pond enters the circulating water pool, the desulfurization waste liquid from the pelletizing system enters the circulating water pool, and the water in the circulating water pool is recycled.

[0005] A method for recycling desulfurization waste liquid in an iron ore comprehensive beneficiation system, the specific steps are as follows: S1: Desulfurization wastewater has an adverse effect on flotation separation, which ultimately leads to an abnormal situation in which the comprehensive recovery rate of mineral processing metals is reduced. The influence of desulfurization wastewater with different hardness on mineral processing separation is analyzed; S2: Select the maximum value of the hardness of the desulfurization waste liquid that is less than or equal to the hardness that does not affect the mineral processing and sorting effect as the control standard when the desulfurization waste liquid enters the system; S3: In order to prevent the desulfurization waste liquid from affecting the mineral processing indicators, it cannot directly enter the circulating water pool through the circulating water pipeline. The desulfurization waste liquid circulation route needs to be optimized. A bypass valve is connected near the outlet of the concentrate return water pipeline of the original pelletizing system to ensure that the desulfurization waste liquid can be switched to the tailings pond when it enters the system through the pipeline. When the desulfurization waste liquid enters the tailings pond, the tailings pond discharge branch pipe is promptly adjusted to the eighth group away from the return water system to ensure that sufficient clarification distance is left. At this time, the hardness of the tailings return water containing desulfurization waste liquid is detected. If it is less than or equal to the control standard concentration in S2, it meets the mineral processing process requirements.

[0006] Preferably, the degree of influence of the hardness of the desulfurization waste liquid on the mineral processing and sorting effect in step S1 is divided into 4 levels. The hardness of the desulfurization waste liquid is 3000 μmol / L, and the comprehensive recovery rate of mineral processing metals is 71.42%, which is almost unaffected compared with the normal circulating water hardness ≤1500 μmol / L and the comprehensive recovery rate of mineral processing metals is 71.50%; the hardness of the desulfurization waste liquid is 5000 μmol / L, and the comprehensive recovery rate of mineral processing metals is 70.88%, and the sorting effect is significantly deteriorated; the hardness of the desulfurization waste liquid is 8000 μmol / L, and the comprehensive recovery rate of mineral processing metals is 67.37%, and the sorting effect is poor; the hardness of the desulfurization waste liquid is ≥10000 μmol / L, the comprehensive recovery rate of mineral processing metals is less than 65%, and the sorting effect is extremely poor.

[0007] Preferably, the method for determining the emptying of the desulfurized waste liquid in step S3 is as follows: starting from the time when the desulfurized waste liquid enters the tailings pond through the tailings conveying pipeline, the hardness value of the mineral processing circulating water is tested every 30 minutes, and production adjustments are made according to the changes in the tested hardness value: (1) When the hardness value is ≤3000μmol / L, the system can realize self-purification of waste liquid; (2) If the hardness value is 3000-5000 μmol / L for two consecutive points, it is determined that there may be leakage, valve failure or other abnormal conditions on site, which may cause the desulfurization waste liquid to enter the circulating water pool directly. The site will immediately conduct an investigation and start the circulating water pool to replenish new water to minimize the adverse effects. The water replenishment control standard is: hardness value 3000-3800 μmol / L, new water replenishment flow rate 200 m³ / h; hardness value 3800-4600 μmol / L, new water replenishment flow rate 400 m³ / h; hardness value>4600 μmol / L, new water replenishment flow rate 600 m³ / h; (3) After all the desulfurization waste liquid in the pelletizing system has been transported, water samples are taken from the outlet of the concentrate return pipe to continue testing the hardness value. According to production tests, when the hardness value of the water sample at the outlet of the concentrate return pipe is lower than 5000μmol / L, after dilution with other normal return water in the circulating water pool, the total circulating water hardness value of the mineral processing is less than 3000μmol / L, which meets the mineral processing process requirements. At this time, it is determined that the desulfurization waste liquid has been completely discharged, the system can resume normal return water, the bypass valve of the concentrate return pipe is closed, and the concentrate is recovered directly into the circulating water pool.

[0008] Compared with the prior art, the present invention has the following beneficial effects: (1) By optimizing the desulfurization waste liquid circulation route and using the tailings pond to reduce the hardness of the desulfurization waste liquid, the desulfurization waste liquid is prevented from destroying the chemical properties of the flotation pulp and affecting the flotation separation effect, thus avoiding fluctuations in mineral processing production. There is no need for separate water treatment, thus reducing costs; (2) After utilizing the desulfurization waste liquid, the hardness of the mineral processing circulating water can always be kept at a low level when the pelletizing process regularly discharges the desulfurization waste liquid, the flotation separation effect is almost unaffected, and the comprehensive metal recovery rate of mineral processing remains at a normal level, which greatly improves the stability of mineral processing production and can basically eliminate the impact of the desulfurization waste liquid on the mineral processing system, thereby achieving the purpose of efficiently utilizing the desulfurization waste liquid circulating water in the mineral processing system. DETAILED DESCRIPTION

[0009] The technical solution of the present invention is described clearly and completely below in conjunction with the embodiments.

[0010] A method for recycling desulfurization waste liquid in an iron ore comprehensive beneficiation system, the specific steps are as follows: S1: Desulfurization waste liquid has an adverse effect on the flotation separation effect, which ultimately leads to an abnormal situation in which the comprehensive recovery rate of mineral processing metals is reduced. The influence of desulfurization waste liquid with different hardness on the mineral processing separation effect is analyzed. The influence of the hardness of desulfurization waste liquid on the mineral processing separation effect is divided into 4 levels. The hardness of desulfurization waste liquid is 3000μmol / L, and the comprehensive recovery rate of mineral processing metals is 71.42%. Compared with the normal circulating water hardness ≤1500μmol / L and the comprehensive recovery rate of mineral processing metals is 71.50%, it is almost unaffected; the hardness of desulfurization waste liquid is 5000μmol / L, the comprehensive recovery rate of mineral processing metals is 70.88%, and the separation effect is significantly worse; the hardness of desulfurization waste liquid is 8000μmol / L, the comprehensive recovery rate of mineral processing metals is 67.37%, and the separation effect is poor; the hardness of desulfurization waste liquid is ≥10000μmol / L, the comprehensive recovery rate of mineral processing metals is less than 65%, and the separation effect is extremely poor; S2: Select the hardness of desulfurization waste liquid ≤ 3000 μmol / L as the control standard when the desulfurization waste liquid enters the system; S3: In order to prevent the desulfurization waste liquid from affecting the mineral processing index, it cannot directly enter the circulating water pool through the circulating water pipeline. The desulfurization waste liquid circulation route needs to be optimized. A bypass valve is connected near the outlet of the concentrate return water pipeline of the original pelletizing system to ensure that the desulfurization waste liquid can be switched to the tailings pond when it enters the system through the pipeline. When the desulfurization waste liquid enters the tailings pond, the tailings pond discharge branch pipe is promptly adjusted to the eighth group away from the return water system to ensure that there is sufficient clarification distance. The mineral processing circulating water is taken every 30 minutes to test its hardness value, and production adjustments are made according to the changes in the hardness value: (1) When the hardness value is ≤3000μmol / L, the system can realize self-purification of waste liquid; (2) If the hardness value is 3000-5000 μmol / L for two consecutive points, it is determined that there may be leakage, valve failure or other abnormal conditions on site, which may cause the desulfurization waste liquid to enter the circulating water pool directly. The site will immediately conduct an investigation and start the circulating water pool to replenish new water to minimize the adverse effects. The water replenishment control standard is: hardness value 3000-3800 μmol / L, new water replenishment flow rate 200 m³ / h; hardness value 3800-4600 μmol / L, new water replenishment flow rate 400 m³ / h; hardness value>4600 μmol / L, new water replenishment flow rate 600 m³ / h; (3) After all the desulfurization waste liquid in the pelletizing system has been transported, water samples are taken from the outlet of the concentrate return pipe to continue testing the hardness value. According to production tests, when the hardness value of the water sample at the outlet of the concentrate return pipe is lower than 5000μmol / L, after dilution with other normal return water in the circulating water pool, the total circulating water hardness value of the mineral processing is less than 3000μmol / L, which meets the mineral processing process requirements. At this time, it is determined that the desulfurization waste liquid has been completely discharged, the system can resume normal return water, the bypass valve of the concentrate return pipe is closed, and the concentrate is recovered directly into the circulating water pool.

Claims

1. A method for recycling desulfurization waste liquid in an iron ore comprehensive beneficiation system, wherein the tailings return water of the tailings pond enters a circulating water pool, the desulfurization waste liquid of the pelletizing system enters a circulating water pool, and the water in the circulating water pool is recycled, characterized in that: The specific steps are as follows: S1: Desulfurization wastewater has an adverse effect on flotation separation, which ultimately leads to an abnormal situation in which the comprehensive recovery rate of mineral processing metals is reduced. The influence of desulfurization wastewater with different hardness on mineral processing separation is analyzed; S2: Select the maximum value of the hardness of the desulfurization waste liquid that is less than or equal to the hardness that does not affect the mineral processing and sorting effect as the control standard when the desulfurization waste liquid enters the system; S3: In order to prevent the desulfurization waste liquid from affecting the mineral processing indicators, it cannot directly enter the circulating water pool through the circulating water pipeline. The desulfurization waste liquid circulation route needs to be optimized. A bypass valve is connected near the outlet of the concentrate return water pipeline of the original pelletizing system to ensure that the desulfurization waste liquid can be switched to the tailings pond when it enters the system through the pipeline. When the desulfurization waste liquid enters the tailings pond, the tailings pond discharge branch pipe is promptly adjusted to the eighth group away from the return water system to ensure that sufficient clarification distance is left. At this time, the hardness of the tailings return water containing desulfurization waste liquid is detected. If it is less than or equal to the control standard concentration in S2, it meets the mineral processing process requirements.

2. The method for recycling desulfurization waste liquid in an iron ore comprehensive beneficiation system according to claim 1, characterized in that: In the step S1, the degree of influence of the hardness of the desulfurization waste liquid on the mineral processing and sorting effect is divided into 4 levels. When the hardness of the desulfurization waste liquid is 3000 μmol / L, the comprehensive recovery rate of mineral processing metals is 71.42%, which is almost unaffected compared with the normal circulating water hardness ≤1500 μmol / L and the comprehensive recovery rate of mineral processing metals is 71.50%. When the hardness of the desulfurization waste liquid is 5000 μmol / L, the comprehensive recovery rate of mineral processing metals is 70.88%, and the sorting effect is significantly deteriorated; when the hardness of the desulfurization waste liquid is 8000 μmol / L, the comprehensive recovery rate of mineral processing metals is 67.37%, and the sorting effect is poor; when the hardness of the desulfurization waste liquid is ≥10000 μmol / L, the comprehensive recovery rate of mineral processing metals is less than 65%, and the sorting effect is extremely poor.

3. The method for recycling desulfurization waste liquid in an iron ore comprehensive beneficiation system according to claim 2, characterized in that: The method for determining the emptying of the desulfurized waste liquid in step S3 is as follows: starting from the time when the desulfurized waste liquid enters the tailings pond through the tailings conveying pipeline, the hardness value of the mineral processing circulating water is tested every 30 minutes, and production adjustments are made according to the changes in the tested hardness value: (1) When the hardness value is ≤3000μmol / L, the system can realize self-purification of waste liquid; (2) If the hardness value is 3000-5000 μmol / L for two consecutive points, it is determined that there may be leakage, valve failure or other abnormal conditions on site, which may cause the desulfurization waste liquid to enter the circulating water pool directly. The site will immediately conduct an investigation and start the circulating water pool to replenish new water to minimize the adverse effects. The water replenishment control standard is: hardness value 3000-3800 μmol / L, new water replenishment flow rate 200 m³ / h; hardness value 3800-4600 μmol / L, new water replenishment flow rate 400 m³ / h; hardness value>4600 μmol / L, new water replenishment flow rate 600 m³ / h; (3) After all the desulfurization waste liquid in the pelletizing system has been transported, water samples are taken from the outlet of the concentrate return pipe to continue testing the hardness value. According to production tests, when the hardness value of the water sample at the outlet of the concentrate return pipe is lower than 5000μmol / L, after dilution with other normal return water in the circulating water pool, the total circulating water hardness value of the mineral processing is less than 3000μmol / L, which meets the mineral processing process requirements. At this time, it is determined that the desulfurization waste liquid has been completely discharged, the system can resume normal return water, the bypass valve of the concentrate return pipe is closed, and the concentrate is recovered directly into the circulating water pool.