A method for recovering and beneficiating weakly magnetic tailings of oxide ore

Abstract

The invention discloses a method for recycling and beneficiating weak magnetic tailings of oxide ore, including a magnetic-flotation-magnetic separation process for the weak magnetic tailings of oxide ore. The purpose of the invention is to provide a method for recycling and beneficiating weak magnetic tailings of oxide ore. In view of the characteristics of low grade, high hardness, complex embedding, and great difficulty in separation of the recycled minerals of weak magnetic tailings of oxide ore in Bayan Obo Mine, the tailings of oxide ore resources are comprehensively utilized. After rare earth separation, magnetic and flotation step-by-step dosing combined separation is carried out to meet the requirements of oxide ore separation, and the grade of oxide concentrate can be effectively improved to a reasonable control range.

Description

Technical Field

[0001] The invention relates to the technical field of ore dressing, and in particular to a method for recycling and dressing weakly magnetic tailings of oxide ore. Background Art

[0002] The Bayan Obo deposit is a large-scale polymetallic symbiotic deposit of iron, rare earth, niobium, etc. in my country. The medium-poor stockpiled ore of the Bayan Obo Iron Mine is the surface oxidized iron ore and a small amount of magnetite ore that cannot be used temporarily in the initial stage of mining the East and Main Mine of the Bayan Obo Iron Mine. It is characterized by low iron grade, long stockpiling time and complex composition. The ore has undergone long-term weathering, water immersion and oxidation, and the physical and chemical properties of the surface have changed, making the ore selection difficult and the selection process complicated.

[0003] With the increase in steel production at Baotou Steel, the demand for iron ore has increased and the beneficiation technology has been improved, it is imperative to develop and utilize the medium-poor stockpiled ore of Bayan Obo Iron Mine as soon as possible. Technical feasibility of stage grinding and stage selection of stockpiled ore Grinding is an important means to achieve the dissociation of useful mineral monomers and provide a reasonable particle size for selection. The particle size of the grinding product directly affects the quality of the concentrate and the metal recovery rate. If the grinding operation is "under-grinded", the useful minerals cannot be fully dissociated into monomers, and the conjoined bodies enter the tailings, which will cause metal loss; if they enter the concentrate, it will lead to the dilution of the concentrate and reduce the separation index. If the grinding operation is "over-grinded", it will cause the minerals to become slimy and deteriorate the beneficiation process. Data show that for Baiyunebo oxide ore, when the ore is ground to -200 mesh 75%, the dissociation degree of iron mineral monomers is 63.65%; when the ore is ground to -200 mesh 95%, the dissociation degree of iron mineral monomers is 81.21%; when the ore is ground to -325 mesh 95%, the dissociation degree of iron mineral monomers is 90%; therefore, fine grinding is necessary for Baiyun ore. At the same time, the mudification of iron minerals is not simply caused by the grinding system, but is closely related to the properties of the ore. When the grinding fineness is 200 mesh 72%, the content of -500 mesh (-0.031mm) in the weak magnetic concentrate is 12.20%, and the iron occupancy rate is 12.90%; while the content of 500 mesh in the strong magnetic concentrate is 23.10%, and the iron occupancy rate is 26.97%. That is to say, even during coarse grinding, the iron minerals of the oxide ore have begun to mud. Generally speaking, the iron loss rate in tailings is lower than that in continuous grinding process when using stage grinding and stage selection process. Analysis shows that when using stage grinding and stage selection process, the pre-classification can be strengthened before the coarse iron concentrate enters the re-grinding, which can effectively reduce the occurrence of over-grinding. The relationship between oxide ores is complex, and it is difficult to effectively recover the Bayan Obo oxide ore. Therefore, we need to further study a new method to further select and bring the greatest economic benefits to the enterprise. Summary of the invention

[0004] The purpose of the present invention is to provide a method for recycling and beneficiating weak magnetic tailings of oxide ore. Aiming at the characteristics of low grade, high hardness, complex embedding and great difficulty in separation of the recycled minerals of weak magnetic tailings of oxide ore in Bayan Obo Mine, the tailings of oxide ore comprehensive utilization are separated by rare earth, and then magnetic and flotation step-by-step dosing and combined separation are carried out to meet the requirements of oxide ore separation. The method can obtain products by reasonably controlling the addition of magnetism and reagents, and has been recognized by enterprises. The reagent system has good stability, strong adaptability, strong mutual coordination, and meets the requirements of different flotation processes respectively. By adding reagents step by step, eliminating impurity elements that affect the separation of oxide ore step by step, and stabilizing indicators step by step, the grade of oxide concentrate can be effectively improved to a reasonable control range.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] The invention discloses a method for recovering and beneficiating weak magnetic tailings of oxide ore, wherein the weak magnetic tailings of oxide ore are subjected to a magnetic-flotation-magnetic separation process, and specifically comprises the following steps:

[0007] 1) Magnetic separation: The iron weak magnetic tailings are mixed evenly and sent to the mill for primary grinding. Water is added while the iron weak magnetic tailings sample is fed into the mill, and the grinding is carried out based on the grinding concentration of 66.67% standard;

[0008] The particle size of the ore obtained by the first magnetic separation is different due to the different grinding time. The -200 mesh particle size is used for rapid screening, and the qualified particle size in different time periods is used as the basis for magnetic separation.

[0009] The secondary magnetic separation is carried out with a -200 mesh particle size for rapid screening. The particle size is controlled at 85%, and the yield and recovery rate are the best. At the same time, the harmful substances of phosphorus and fluorine are the least. Then, the magnetic separation is controlled, and each magnetic separation series is reasonably coordinated and controlled to reach the best magnetic separation field strength of 1.3T.

[0010] 2) Flotation: The ore pulp after magnetic separation is recovered and flotation is performed once to achieve the maximum economic value and the lowest environmental pollution index. The ore pulp after 1.3T magnetic separation with a particle size of 85% tailings is added with a low-temperature collector for collection. After determining that the optimal conditions of the low-temperature collector are 24ml and the pH value is 5-5.5, the quality, yield, grade, metal content and recovery rate are the most reasonable;

[0011] 4) Flotation and fine magnetic separation: The ore pulp that has been separated above is separated again to achieve the maximum economic benefit. After reasonable control and comparison through various magnetic separation-flotation-flotation and fine magnetic separation series, the best magnetic separation field strength is 0.5T.

[0012] Furthermore, in the step 1), the ore grade is: TFe=15.6%, P=1.384%, F=11.070%. In the laboratory, the iron ore concentrate grade is finally separated to be 64.10%, the process yield is 2.57%, the process recovery rate is 11.16%, the fluorine is 0.723%, and the phosphorus is 0.114%.

[0013] Furthermore, in flotation, a one-rough and two-fine flotation process is adopted, 36 ml of ammonium fluorosilicate is first added in the roughing, and then 24 ml of low-temperature collector is added at one time, 5 ml of ammonium fluorosilicate is added in the first fine, and 2 ml of ammonium fluorosilicate is added in the second fine. Ammonium fluorosilicate is an inhibitor.

[0014] Compared with the prior art, the beneficial technical effects of the present invention are:

[0015] The present invention can provide effective technical guarantee for enterprises to recycle concentrates by re-selecting and comprehensively reusing tailings after selection, effectively controlling the particle size and magnetic separation of tailings, and then flotation, and finally flotation selection. The selection of this product method is simple and convenient for combined application. Through multiple combined applications, the products required by the enterprise can be obtained again. This method is suitable for ore dressing sites with difficult selection. The invention method only needs to add equipment and reagents to obtain products, prolongs the utilization time of the tailings pond, effectively protects the safety of equipment and operators, and can reduce the labor intensity of operators.

[0016] This product is easy to assemble and has a wide range of applications. It can be used freely in on-site environments with a variety of mixed slurries. It is widely used in mineral processing engineering and automation control fields, especially in the technical field of mixing a variety of ores.

[0017] The invention is simple and convenient to use on site, and has the following advantages: 1. No extra personnel are needed to help, and one person can complete the operation by adjustment. 2. The process is convenient to combine and easy to understand. 3. When the process is used for mineral processing, it is labor-saving, safe, easy to operate and protects personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings.

[0019] Figure 1 The present invention is a schematic diagram of the process of the recovery and beneficiation method of the weakly magnetic tailings of the oxide ore. DETAILED DESCRIPTION

[0020] A method for recovering and beneficiating weak magnetic tailings of oxide ore comprises: the weak magnetic tailings of oxide ore are subjected to a magnetic-flotation-magnetic separation process, specifically comprising the following steps:

[0021] 1) Magnetic separation: Dry and mix the iron weak magnetic tailings evenly and send them into the mill for primary grinding. Add water while feeding the iron weak magnetic tailings sample into the mill, and grind them based on the grinding concentration of 66.67%. The particle size of the grinding is different due to the different grinding time. Rapid screening is carried out with a particle size of -200 mesh, and the qualified particle size of different time periods is screened out as the basis for magnetic separation; the particle size of the grinding is different due to the different grinding time. Rapid screening is carried out with a particle size of -200 mesh, and the qualified particle size of different time periods is screened out as the basis for magnetic separation; through measurement and research, it is found that only when the particle size is controlled at 85%, the yield and recovery rate are the best, and the harmful substances of phosphorus and fluorine are also the least. The secondary magnetic separation is carried out with a -200 mesh particle size for rapid screening. When the particle size is controlled at 85%, the yield and recovery rate are the best, and the phosphorus and fluorine harmful substances are the least. Then, the magnetic separation is controlled, and after reasonable coordination and control comparison of each magnetic separation series, the best magnetic separation field strength is 1.3T, and the most reasonable is selected. The yield and recovery rate are the best, and the phosphorus and fluorine harmful substances are the least.

[0022] 2) Flotation: The ore pulp that has been through magnetic separation is recovered. The first flotation is carried out to achieve the maximum economic value and the lowest environmental pollution index. The ore pulp with a particle size of 85% tailings, after 1.3T magnetic separation, is collected by adding a low-temperature collector. After determining that the optimal condition of the low-temperature collector is 24ml and the pH value is 5-5.5, the quality, yield, grade, metal content and recovery rate are the most reasonable. The second flotation is carried out to recover the ore pulp that has been through magnetic separation. The flotation is carried out to achieve the maximum economic value and the lowest environmental pollution index. The ore pulp with a particle size of 85% tailings, after 1.3T magnetic separation, is collected by the low-temperature collector with the optimal condition of 24ml and the pH value of 5-5.5. After the low-temperature collector is collected, the optimal condition of the inhibitor is 24ml and the pH value is 5-5.5. The collection is carried out to obtain the most reasonable quality, yield, grade, metal content and recovery rate. In flotation, a one-rough and two-fine flotation process is adopted. In the roughing, 36 ml of ammonium fluorosilicate is first added, and then 24 ml of low-temperature collector is added at one time. In the first fine, 5 ml of ammonium fluorosilicate is added, and in the second fine, 2 ml of ammonium fluorosilicate is added. Ammonium fluorosilicate is an inhibitor.

[0023] 3) Flotation and fine magnetic separation: The ore pulp that has been separated above is separated again to achieve the maximum economic benefit. After reasonable and controlled comparison of each magnetic separation-flotation-flotation and fine magnetic separation series, the best magnetic separation field strength is 0.5T, and the most reasonable one is selected to obtain the best quality, yield, grade, metal content and recovery rate.

[0024] The grade of the original ore is: TFe=15.6%, P=1.384%, F=11.070%. The laboratory uses the process of magnetic separation 1.3T-positive flotation-magnetic separation 0.5T, and the final iron concentrate grade is 64.10%, the process yield is 2.57%, the process recovery rate is 11.16%, the fluorine is 0.723%, and the phosphorus is 0.114%.

[0025] In the step 1), the product particle size of -200 mesh accounts for 85%, which is the most reasonable.

[0026]

[0027] In the step 1), the product particle size of -200 mesh accounts for 85%, and the magnetic separation field strength is 1.3T, which is the most reasonable.

[0028]

[0029] In the step 2), the optimum condition of the low-temperature collector is 24 ml, and the most reasonable pH value is 5-5.5.

[0030]

[0031] In the step 2), the optimal conditions for the inhibitor are 24 ml and the most reasonable pH value is 5-5.5.

[0032] The analysis in step 2) shows that this method has the most reasonable economic effect.

[0033] Yield grade Yield silicon phosphorus sulfur fluorine Potassium sodium 16.94 62.00 42.85 0.663 0.211 1.844 1.566 0.023 0.053

[0034] Working process: after the iron weak magnetic tailings sample is mixed evenly, it is ground to different particle sizes, magnetic separation is carried out when the field strength remains unchanged, the optimal particle size is determined, and then magnetic separation is carried out for different magnetic field strengths, and the best field strength is determined to be 1.3T for magnetic separation. Then, ammonium fluorosilicate and low-temperature collectors are respectively floated again, and the optimal condition for low-temperature collectors is 24ml. After the low-temperature collector is captured when the pH value is 5-5.5, the optimal condition for adding inhibitors is 24ml. When the pH value is 5-5.5, it is most reasonable to capture and obtain quality, yield, grade, metal content, and recovery rate. It is 0.5T to carry out flotation fine magnetic separation again to reach the best magnetic separation field strength, and select the most reasonable. The quality, yield, grade, metal content, and recovery rate obtained are the best. For enterprises to achieve maximum economic benefits, the most reasonable oxide ore can be obtained after reasonable control of each magnetic separation-flotation-flotation fine magnetic separation series.

[0035] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for recovering and dressing weak magnetic tailings of oxide ore, characterized in that: The weak magnetic tailings of oxide ore are separated by magnetic-flotation-magnetic separation process, which specifically includes the following steps: 1) Magnetic separation: The iron weak magnetic tailings are mixed evenly and sent to the mill for primary grinding. Water is added while the iron weak magnetic tailings sample is fed into the mill, and the grinding is carried out based on the grinding concentration of 66.67% standard; The particle size of the ore obtained by the first magnetic separation is different due to the different grinding time. The -200 mesh particle size is used for rapid screening, and the qualified particle size in different time periods is used as the basis for magnetic separation. The secondary magnetic separation is carried out with a -200 mesh particle size for rapid screening. The particle size is controlled at 85%, and the yield and recovery rate are the best. At the same time, the harmful substances of phosphorus and fluorine are the least. Then, the magnetic separation is controlled, and each magnetic separation series is reasonably coordinated and controlled to reach the best magnetic separation field strength of 1.3T. 2) Flotation: The ore pulp after magnetic separation is recovered and flotation is performed once to achieve the maximum economic value and the lowest environmental pollution index. The ore pulp after 1.3T magnetic separation with a particle size of 85% tailings is added with a low-temperature collector for collection. After determining that the optimal conditions of the low-temperature collector are 24ml and the pH value is 5-5.5, the quality, yield, grade, metal content and recovery rate are the most reasonable; 3) Flotation and fine magnetic separation: The ore pulp that has been separated above is separated again to achieve the maximum economic benefit. After reasonable control and comparison through various magnetic separation-flotation-flotation and fine magnetic separation series, the best magnetic separation field strength is 0.5T.

2. The method for recovering and dressing the oxide ore weak magnetic tailings according to claim 1, characterized in that: In the step 1), the raw ore grade is: TFe=15.6%, P=1.384%, and F=11.070%. The laboratory uses a process of magnetic separation 1.3T-positive flotation-magnetic separation 0.5T, and the final iron concentrate grade is 64.10%, the process yield is 2.57%, the process recovery rate is 11.16%, the fluorine is 0.723%, and the phosphorus is 0.114%.

3. The method for recovering and dressing the oxide ore weak magnetic tailings according to claim 1, characterized in that: In flotation, a one-rough and two-fine flotation process is adopted. In the roughing, 36 ml of ammonium fluorosilicate is first added, and then 24 ml of low-temperature collector is added at one time. In the first fine separation, 5 ml of ammonium fluorosilicate is added, and in the second fine separation, 2 ml of ammonium fluorosilicate is added.

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