Method for recovering phosphorite from micro-fine particle tailings

Abstract

The invention relates to the technical field of mineral resource recovery and environment-friendly beneficiation, and discloses a method for recovering phosphorite from micro-fine fraction tailings, which comprises the following steps: grading by a cyclone: micro-fine fraction ore pulp is introduced into the cyclone for grading, an overflow product enters an overflow pipe, and a sand setting product enters a subsequent desulfurization flotation process; carrying out copper-sulfur separation flotation: carrying out dehydration treatment on the crude copper concentrate obtained after desulfurization, and then entering a copper-sulfur separation flotation process to separate out copper fine powder and sulfur fine powder; the desulfurized minerals enter the micro-fine particle grade phosphorus selection process, the flotation process of one-roughing, one-sweeping and four-concentrating is adopted, and phosphorus concentrate is selected. According to the method, high-efficiency purification of copper and sulfur concentrates is achieved and tailing pollution is reduced through concentration classification of a cyclone, impurity removal of an inclined plate, desulfurization flotation and copper-sulfur separation flotation, in the phosphorite recycling process, the flotation process of one-time roughing, one-time sweeping and four-time concentration is adopted, automatic control equipment is arranged, and the recycling rate and purity of the phosphate concentrates are remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of mineral resource recovery and environmentally friendly ore dressing, and in particular to a method for recovering phosphate minerals from micro-fine tailings. Background Art

[0002] In the process of mineral resource development, a large amount of fine-grained tailings are produced, which contain rich phosphorus minerals. However, due to the extremely small particles of these minerals, traditional mineral processing methods are limited in their effectiveness in recovering these fine-grained minerals, resulting in a large amount of resources entering the tailings pond, which not only causes resource waste, but also brings environmental pollution and land occupation problems. In addition, the tailings also contain valuable elements such as phosphorus, copper, and sulfur, which are difficult to separate efficiently using existing technologies, further exacerbating resource losses.

[0003] As an important resource, phosphate minerals are widely used in agriculture, chemical industry, energy and other fields. As phosphate resources gradually decrease, it is particularly important to improve the recovery rate of phosphate minerals in tailings. However, the existing fine-grained tailings recovery technology faces multiple difficulties. Due to the small particle size of the mineral, traditional sorting equipment is difficult to effectively recover phosphate minerals; during the flotation process, the consumption of reagents and energy is large, which further increases the production cost; at the same time, the existing process relies on manual operation and has a low degree of automation. It is not only complicated to operate and inefficient, but also difficult to achieve large-scale and stable production. In order to meet these challenges, the present invention proposes a method for recovering phosphate minerals from fine-grained tailings. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a method for recovering phosphate minerals from fine-grained tailings, which solves the problems of difficulty in efficiently recovering phosphate minerals from fine-grained tailings, waste of resources and environmental pollution.

[0005] To achieve the above objectives, the present invention is implemented by the following technical scheme: A method for recovering phosphate minerals from fine-grained tailings, comprising the following steps:

[0006] Hydrocyclone classification: The fine-grained slurry is introduced into the hydrocyclone for classification, the overflow product enters the overflow pipe, and the sedimentation product enters the subsequent desulfurization flotation process;

[0007] Copper-sulfur separation flotation: The crude copper concentrate obtained after desulfurization is dehydrated and then enters the copper-sulfur separation flotation process to separate copper concentrate and sulfur concentrate;

[0008] Phosphorus flotation process: The desulfurized minerals enter the fine-grained phosphorus selection process, using a one-roughing, one-sweeping and four-fine flotation process to select the phosphate concentrate, and the rest is discharged as tailings;

[0009] Dehydration of phosphate concentrate: The phosphate concentrate is sent to the disc filter for dehydration to obtain the final phosphate concentrate powder.

[0010] Preferably, the cyclone classification specifically comprises the following steps:

[0011] Slurry preparation: adjust the slurry concentration of fine iron ore tailings to 2-4%, the copper grade mass percentage in the ore sample should be controlled between 0.04%-0.07%, and the phosphorus grade mass percentage should be between 3%-3.5%;

[0012] Entering the inclined plate for grading and impurity removal:

[0013] The slurry first enters the inclined plate for classification, and the overflow port of the inclined plate discharges the finer-grained minerals;

[0014] Install a screen with a pore size of 1-2mm at the overflow outlet of the inclined plate to remove large particles of impurities;

[0015] Cyclone classification operation:

[0016] After the impurities are removed by the inclined plate, the slurry enters the cyclone for further classification. The working pressure of the cyclone is controlled at 0.2-0.4MPa;

[0017] The overflow product flows into the overflow pipe by gravity;

[0018] The sedimentation product enters the desulfurization flotation process.

[0019] Preferably, the particle size range parameters in the slurry preparation step are: D50=6.862 μm; D75=16.00 μm; D90=29.47 μm; D97=49.54 μm.

[0020] Preferably, the copper-sulfur separation flotation specifically comprises the following steps:

[0021] Desulfurization flotation: send the sedimentation product pulp into the desulfurization flotation tank, adjust the pulp pH value to 7.5-8.5, add an appropriate amount of collector, and perform a flotation;

[0022] Dehydration treatment: The desulfurized crude copper concentrate is initially dehydrated to adjust the pulp concentration to 30-40% in preparation for subsequent copper-sulfur separation and flotation;

[0023] Copper-sulfur separation flotation: The dehydrated pulp is sent to the copper-sulfur separation flotation process, the pH value is adjusted to 8.0-8.5, the amount of collector is controlled at 50-80g / t, and the copper concentrate is selectively floated;

[0024] Sulfur concentrate and copper concentrate are obtained by separation and collection, with the copper grade controlled at more than 15% and the sulfur grade at more than 20%.

[0025] Preferably, the collector for desulfurization flotation is xanthate, and the concentration is controlled at 20-40 g / t.

[0026] Preferably, the phosphorus flotation process specifically includes the following steps:

[0027] Phosphorus flotation process:

[0028] Phosphate minerals are recovered through flotation process, which adopts "one roughing, one sweeping and four fines":

[0029] Automation control:

[0030] Use automated equipment to control the flotation liquid level at 2-5 cm;

[0031] During the flotation process, a foam layer thickness sensor and an automatic adjustment system are used to achieve automatic control of flotation;

[0032] Tailings discharge: Phosphate tailings enter the tailings pond through the tailings pipeline.

[0033] Preferably, the specific steps of one roughing, one sweeping and four fines are as follows:

[0034] First roughing: adding collector and frother, the collector dosage is 50-70g / t, the frother dosage is 20-30g / t, so as to make the phosphate minerals initially enriched in the roughing;

[0035] One sweep: further remove impurities and minerals, and maintain the pH value at 8.0-8.5;

[0036] Four concentrate flotation steps: four concentrate flotation steps are carried out, and each step uses precisely adjusted collector and frother concentrations to gradually enrich the phosphate concentrate to the required purity.

[0037] Preferably, the four steps of concentrated ore flotation are as follows:

[0038] First concentrate flotation:

[0039] Collector: Use fatty acid collector, the concentration is controlled at 30-40g / t;

[0040] Frothing agent: Use methyl isobutyl carbinol as foaming agent, with a concentration of 10-15g / t;

[0041] Slurry pH value: adjusted to 7.5-8.0;

[0042] Flotation time: controlled at 5-7 minutes to obtain initially enriched phosphate concentrate;

[0043] Second concentrate flotation:

[0044] Collector concentration adjustment: reduce collector concentration to 25-35g / t;

[0045] Adjustment of foaming agent concentration: maintain at 8-12g / t;

[0046] Slurry pH value: fine-tuned to 8.0-8.5;

[0047] Flotation time: shortened to 4-6 minutes, rapid capture of phosphate minerals;

[0048] The third concentrate flotation:

[0049] Collector concentration is further reduced: to 20-30g / t;

[0050] Frothing agent concentration maintenance: maintain 8-10g / t;

[0051] Slurry pH value: maintained at 8.0-8.5;

[0052] Flotation time: 3-5min, further enriching phosphorus minerals;

[0053] The fourth concentrate flotation:

[0054] Collector fine-tuning: down to 15-25g / t;

[0055] Foaming agent: controlled at 5-8g / t;

[0056] Slurry pH value: maintained at 8.0-8.5;

[0057] Flotation time: 3-4 minutes, to complete the final enrichment of phosphate minerals and obtain high-purity phosphate concentrate.

[0058] Preferably, the dehydration of phosphate concentrate specifically comprises the following steps:

[0059] Disc filter filtration: The phosphate concentrate obtained by four-fine flotation is sent to the disc filter for dehydration. The working pressure of the filter is set at 0.2-0.3MPa, and finally the phosphate concentrate with a solid water content of 10%-15% is obtained;

[0060] Automatic cake unloading: Use the automatic cake unloading function of the filter to unload the solids. The cake unloading cycle of the filter should be controlled within 10-15 minutes;

[0061] Final product: Dehydrated phosphorus concentrate with a phosphorus grade of 28%-30%, which is a high-purity phosphorus mineral that meets product standards.

[0062] The present invention provides a method for recovering phosphate minerals from fine-grained tailings. It has the following beneficial effects:

[0063] 1. The present invention uses a cyclone to initially concentrate and classify the fine-grained tailings, and installs a screen at the overflow outlet of the inclined plate to remove large-particle impurities. This not only improves the sorting efficiency of phosphate minerals in the tailings, but also effectively avoids the problem of equipment blockage caused by impurities, creating a stable classification environment for the subsequent flotation process.

[0064] 2. The present invention aims at copper-containing and sulfur-containing minerals in tailings, and realizes efficient separation and purification of copper concentrate and sulfur concentrate through a desulfurization flotation and copper-sulfur separation flotation. In addition, by accurately controlling the type and concentration of flotation agents, high-grade copper and sulfur concentrates are obtained, thereby improving the utilization rate of mineral resources and effectively reducing tailings pollution.

[0065] 3. In the recovery of phosphate minerals, the present invention adopts a "one roughing, one sweeping and four fine" flotation process and is equipped with automatic control equipment. By accurately controlling the concentration of collector and frother, and automatically adjusting the thickness of the flotation foam layer and the liquid level, the recovery rate and purity of phosphate minerals are effectively improved, the flotation efficiency is optimized, and the energy consumption is reduced, making the production process of phosphate concentrate more efficient and economical.

[0066] 4. The phosphate concentrate obtained by flotation in the present invention is dehydrated by a disc filter, and the automatic cake unloading and automatic flushing functions are utilized, so that the manual operation is reduced during the dehydration of the phosphate concentrate, and the dryness and purity of the solid product are ensured. The efficient dehydration process of this step not only improves the work efficiency, but also ensures the quality of the final product. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 is a flow chart of the method of the present invention;

[0068] Figure 2 It is a process framework diagram of the present invention. DETAILED DESCRIPTION

[0069] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0070] Please see attached Figure 1 -Attached Figure 2 The embodiment of the present invention provides a method for recovering phosphate minerals from fine tailings, comprising the following steps:

[0071] Hydrocyclone classification: The fine-grained slurry is introduced into the hydrocyclone for classification, the overflow product enters the overflow pipe, and the sedimentation product enters the subsequent desulfurization flotation process;

[0072] Copper-sulfur separation flotation: The crude copper concentrate obtained after desulfurization is dehydrated and then enters the copper-sulfur separation flotation process to separate copper concentrate and sulfur concentrate;

[0073] Phosphorus flotation process: The desulfurized minerals enter the fine-grained phosphorus selection process, using a one-roughing, one-sweeping and four-fine flotation process to select the phosphate concentrate, and the rest is discharged as tailings;

[0074] Dehydration of phosphate concentrate: The phosphate concentrate is sent to the disc filter for dehydration to obtain the final phosphate concentrate powder.

[0075] The cyclone classification specifically includes the following steps:

[0076] Slurry preparation: adjust the slurry concentration of fine iron ore tailings to 2-4%, the copper grade mass percentage in the ore sample should be controlled between 0.04%-0.07%, and the phosphorus grade mass percentage should be between 3%-3.5%;

[0077] Entering the inclined plate for grading and impurity removal:

[0078] The slurry first enters the inclined plate for classification, and the overflow port of the inclined plate discharges the finer-grained minerals;

[0079] Install a screen with a pore size of 1-2mm at the overflow outlet of the inclined plate to remove large particles of impurities;

[0080] Cyclone classification operation:

[0081] After the impurities are removed by the inclined plate, the slurry enters the cyclone for further classification. The working pressure of the cyclone is controlled at 0.2-0.4MPa;

[0082] The overflow product flows into the overflow pipe by gravity;

[0083] The sedimentation product enters the desulfurization flotation process.

[0084] The particle size range parameters in the slurry preparation step are: D50 = 6.862 μm; D75 = 16.00 μm; D90 = 29.47 μm; D97 = 49.54 μm.

[0085] Copper-sulfur separation flotation specifically includes the following steps:

[0086] Desulfurization flotation: send the sedimentation product pulp into the desulfurization flotation tank, adjust the pulp pH value to 7.5-8.5, add an appropriate amount of collector, and perform a flotation;

[0087] Dehydration treatment: The desulfurized crude copper concentrate is initially dehydrated to adjust the pulp concentration to 30-40% in preparation for subsequent copper-sulfur separation and flotation;

[0088] Copper-sulfur separation flotation: The dehydrated pulp is sent to the copper-sulfur separation flotation process, the pH value is adjusted to 8.0-8.5, the amount of collector is controlled at 50-80g / t, and the copper concentrate is selectively floated;

[0089] Sulfur concentrate and copper concentrate are obtained by separation and collection, with the copper grade controlled at more than 15% and the sulfur grade at more than 20%.

[0090] The collector for desulfurization flotation is xanthate, and the concentration is controlled at 20-40g / t.

[0091] The phosphorus flotation process specifically includes the following steps:

[0092] Phosphorus flotation process:

[0093] Phosphate minerals are recovered through flotation process, which adopts "one roughing, one sweeping and four fines":

[0094] Automation control:

[0095] Use automated equipment to control the flotation liquid level at 2-5 cm;

[0096] During the flotation process, a foam layer thickness sensor and an automatic adjustment system are used to achieve automatic control of flotation;

[0097] Tailings discharge: Phosphate tailings enter the tailings pond through the tailings pipeline.

[0098] The specific steps of one rough, one sweep and four fine are as follows:

[0099] First roughing: adding collector and frother, the collector dosage is 50-70g / t, the frother dosage is 20-30g / t, so as to make the phosphate minerals initially enriched in the roughing;

[0100] One sweep: further remove impurities and minerals, and maintain the pH value at 8.0-8.5;

[0101] Four concentrate flotation steps: four concentrate flotation steps are carried out, and each step uses precisely adjusted collector and frother concentrations to gradually enrich the phosphate concentrate to the required purity.

[0102] The four steps of flotation of concentrated ore are as follows:

[0103] First concentrate flotation:

[0104] Collector: Use fatty acid collector, the concentration is controlled at 30-40g / t;

[0105] Frothing agent: Use methyl isobutyl carbinol as foaming agent, with a concentration of 10-15g / t;

[0106] Slurry pH value: adjusted to 7.5-8.0;

[0107] Flotation time: controlled at 5-7 minutes to obtain initially enriched phosphate concentrate;

[0108] Second concentrate flotation:

[0109] Collector concentration adjustment: reduce collector concentration to 25-35g / t;

[0110] Adjustment of foaming agent concentration: maintain at 8-12g / t;

[0111] Slurry pH value: fine-tuned to 8.0-8.5;

[0112] Flotation time: shortened to 4-6 minutes, rapid capture of phosphate minerals;

[0113] The third concentrate flotation:

[0114] Collector concentration is further reduced: to 20-30g / t;

[0115] Frothing agent concentration maintenance: maintain 8-10g / t;

[0116] Slurry pH value: maintained at 8.0-8.5;

[0117] Flotation time: 3-5min, further enriching phosphorus minerals;

[0118] The fourth concentrate flotation:

[0119] Collector fine-tuning: down to 15-25g / t;

[0120] Foaming agent: controlled at 5-8g / t;

[0121] Slurry pH value: maintained at 8.0-8.5;

[0122] Flotation time: 3-4 minutes, to complete the final enrichment of phosphate minerals and obtain high-purity phosphate concentrate.

[0123] The dehydration of phosphate concentrate specifically includes the following steps:

[0124] Disc filter filtration: The phosphate concentrate obtained by four-fine flotation is sent to the disc filter for dehydration. The working pressure of the filter is set at 0.2-0.3MPa, and finally the phosphate concentrate with a solid water content of 10%-15% is obtained;

[0125] Automatic cake unloading: Use the automatic cake unloading function of the filter to unload the solids. The cake unloading cycle of the filter should be controlled within 10-15 minutes;

[0126] Final product: Dehydrated phosphorus concentrate with a phosphorus grade of 28%-30%, which is a high-purity phosphorus mineral that meets product standards.

[0127] Embodiment 1:

[0128] Slurry preparation:

[0129] The fine-grained iron ore tailings were made into slurry and the concentration was adjusted to 3%. The copper grade in the ore sample was 0.05% and the phosphorus grade was 3.2%.

[0130] The particle size distribution of the slurry is adjusted during the preparation process and controlled at D50 = 6.862 μm; D75 = 16.00 μm; D90 = 29.47 μm; and D97 = 49.54 μm.

[0131] Cyclone classification:

[0132] The slurry is introduced into the cyclone for classification, and the working pressure of the cyclone is controlled at 0.3MPa.

[0133] The finer overflow products flow into the overflow pipe by gravity, and the coarser sedimentation products enter the subsequent desulfurization flotation process.

[0134] Copper and sulfur separation flotation:

[0135] The sedimentation product enters the desulfurization flotation tank, the pH value is adjusted to 8.0, and xanthate is added as a collector, and the concentration is controlled at 30g / t.

[0136] The crude copper concentrate after desulfurization is dehydrated to a pulp concentration of 30-40%, and then enters the copper-sulfur separation flotation. The pH value is adjusted to 8.2, the collector dosage is 50g / t, and the copper concentrate is selectively floated.

[0137] Finally, the copper concentrate grade reached 15% and the sulfur concentrate grade reached 20%.

[0138] Phosphorus flotation:

[0139] The desulfurized minerals enter the "one roughing, one sweeping and four fine" flotation process. The flotation liquid level is maintained at 3cm.

[0140] The collector dosage is 60g / t, the frother dosage is 25g / t, and the pH value is set to 8.3 to ensure that the phosphate minerals are enriched in the rough selection and other impurities are removed.

[0141] Dehydration of phosphate concentrate:

[0142] The obtained phosphate concentrate is sent to a disc filter with a filtration pressure of 0.25 MPa to reduce the solid moisture content to 12%.

[0143] The automatic cake unloading function ensures that the cake unloading is completed within 12 minutes to obtain the final phosphorus concentrate.

[0144] Summary: Example 1 successfully recovered phosphate minerals through basic cyclone classification, copper-sulfur separation and phosphorus flotation processes, meeting the preliminary product standards.

[0145] Embodiment 2

[0146] Based on the first embodiment, the optimization was carried out to further improve the concentrate grade and efficiency:

[0147] Slurry preparation:

[0148] The slurry concentration was increased to 3%, the copper grade was 0.06% and the phosphorus grade was 3.3%.

[0149] Cyclone classification:

[0150] The cyclone operating pressure is increased to 0.35MPa to separate mineral particles more effectively.

[0151] Copper and sulfur separation flotation:

[0152] During the desulfurization flotation process, the pH value was adjusted to 8.1 and the collector xanthate concentration was increased to 32 g / t to enhance the separation of copper and sulfur minerals.

[0153] After desulfurization, the crude copper concentrate is dehydrated to a concentration of 30-40%, and then enters the copper-sulfur separation process, the pH value is set to 8.3, and the collector dosage is 55g / t.

[0154] The copper concentrate grade increased to 16%, and the sulfur concentrate grade increased to 21%.

[0155] Phosphorus flotation:

[0156] The flotation liquid level was increased to 3.5 cm, the collector dosage was increased to 65 g / t, the frother dosage was 28 g / t, and the pH value was adjusted to 8.4 to ensure the enrichment effect of the phosphate concentrate.

[0157] Dehydration of phosphate concentrate:

[0158] The filtration pressure increased to 0.28MPa, reducing the solid moisture content to 11% and shortening the cake unloading cycle to 11 minutes.

[0159] Summary: Example 2 optimizes the pulp concentration, cyclone classification and flotation efficiency, and significantly improves the grade of copper and phosphate concentrate.

[0160] Embodiment 3

[0161] Further optimization is performed on the basis of Example 2 to improve the slurry concentration and cyclone efficiency:

[0162] Slurry preparation:

[0163] Increase the slurry concentration to 3.5%, the copper grade to 0.065%, and the phosphorus grade to 3.4%.

[0164] Cyclone classification:

[0165] The cyclone operating pressure is increased to 0.37MPa to further improve the classification efficiency.

[0166] Copper and sulfur separation flotation:

[0167] The pH value of desulfurization flotation was adjusted to 8.2, and the dosage of xanthate was 35g / t, which improved the desulfurization effect.

[0168] During the copper-sulfur separation flotation process, the pH value was adjusted to 8.4 and the collector dosage was 60 g / t, so that the copper concentrate grade reached 17% and the sulfur concentrate grade reached 22%.

[0169] Phosphorus flotation:

[0170] The flotation liquid level was increased to 4 cm, the collector dosage was 68 g / t, the frother dosage was 30 g / t, and the pH value was controlled at 8.5, which increased the enrichment of phosphate minerals.

[0171] Dehydration of phosphate concentrate:

[0172] The filtration pressure was maintained at 0.3 MPa, the moisture content was further reduced to 10%, and the cake unloading cycle was shortened to 10 minutes.

[0173] Summary: Example 3 further improves the purity and recovery rate of the concentrate through higher cyclone pressure and flotation reagent concentration.

[0174] Embodiment 4

[0175] Based on the above examples, the concentration of the reagent and the separation efficiency are further finely controlled:

[0176] Slurry preparation:

[0177] The slurry concentration increased to 3.7%, the copper grade was 0.067%, and the phosphorus grade was 3.45%.

[0178] Cyclone classification:

[0179] The cyclone operating pressure is increased to 0.38MPa, further improving the separation effect of minerals.

[0180] Copper and sulfur separation flotation:

[0181] The pH value of desulfurization flotation was increased to 8.3, and the dosage of xanthate was 37g / t, which further improved the copper-sulfur separation effect.

[0182] In the copper-sulfur separation flotation, the pH value was adjusted to 8.45, the collector dosage was 65g / t, and the grades of copper concentrate and sulfur concentrate were increased to 18% and 23%, respectively.

[0183] Phosphorus flotation:

[0184] The flotation liquid level increased to 4.3 cm, the collector dosage was 70 g / t, the frother concentration was 32 g / t, and the pH value was 8.5, which improved the enrichment efficiency of the phosphate concentrate.

[0185] Dehydration of phosphate concentrate:

[0186] The filter pressure is maintained at 0.3MPa, the water content is stabilized at 10%, and the cake unloading cycle is controlled within 10 minutes.

[0187] Summary: Example 4 further improves the separation efficiency of copper, sulfur and phosphate concentrates through precise flotation conditions and higher reagent concentration, ensuring the purity and recovery effect of the concentrates.

[0188] Embodiment 5

[0189] Based on the above examples, each parameter is adjusted to the best to obtain the most efficient separation effect:

[0190] Slurry preparation:

[0191] The slurry concentration was increased to 4%, the copper grade was 0.07%, and the phosphorus grade was 3.5%.

[0192] Cyclone classification:

[0193] The cyclone operating pressure is increased to 0.4MPa to ensure the maximum separation efficiency of minerals.

[0194] Copper and sulfur separation flotation:

[0195] The pH value of desulfurization flotation was increased to 8.4, and the dosage of xanthate was 40g / t to maximize the separation effect.

[0196] In copper-sulfur separation, the pH value is set to 8.5, the collector dosage is 72 g / t, the copper concentrate grade is increased to 20%, and the sulfur concentrate grade reaches 24%.

[0197] Phosphorus flotation:

[0198] The flotation liquid level was adjusted to 5 cm, the collector dosage was 72 g / t, the frother dosage was 35 g / t, and the pH value was maintained at 8.5 to ensure maximum enrichment of phosphate minerals.

[0199] Dehydration of phosphate concentrate:

[0200] The filtration pressure is maintained at 0.3 MPa, the water content is stabilized at 10%, and the cake unloading cycle is stabilized at 10 minutes to obtain high-purity phosphorus concentrate.

[0201] Summary: Example 5 achieves the highest pulp concentration, cyclone pressure and flotation agent dosage, achieves the highest purity of phosphate concentrate and the best recovery effect of copper-sulfur concentrate, and meets the needs of industrial applications.

[0202] Summary:

[0203] These five embodiments gradually optimized the pulp concentration, cyclone classification pressure, copper-sulfur flotation pH value and phosphorus flotation reagent dosage, achieving a gradual increase in resource recovery rate and concentrate grade. Finally, Example 5 achieved the best effect, significantly improving the purity and recovery efficiency of copper, sulfur and phosphorus concentrates, and achieving the goals of clean production and energy saving and consumption reduction.

[0204] Experimental design:

[0205] Purpose:

[0206] The purpose of this experiment is to verify the advantages of the fine-grained tailings recovery process of the present invention over traditional tailings treatment technology in terms of resource recovery rate, concentrate purity, production efficiency, etc.

[0207] Experimental design overview:

[0208] The experiment compares the conventional process with embodiments 1 to 5 of the present invention, and analyzes and compares the following key indicators through system testing and data collection:

[0209] Concentrate purity and recovery rate of phosphate minerals, copper minerals and sulfur minerals

[0210] Process efficiency of reagent usage

[0211] Energy consumption and time cost in the production process

[0212] Experimental materials and equipment

[0213] Materials: Fine-grained iron ore tailings samples, with phosphorus content of 3%-3.5% and copper content of 0.04%-0.07%.

[0214] Equipment: cyclone, flotation machine, disc filter, automatic control system, pH adjustment system, foam layer thickness sensor, liquid level controller, etc.

[0215] Experimental steps:

[0216] Sample preparation:

[0217] The same batch of fine-grained iron ore tailings was used, and the slurry concentration was controlled at 3% to ensure that the experimental conditions were consistent.

[0218] Experimental group design:

[0219] Control group: The experiment was conducted using the traditional tailings treatment process, following the common flotation and dewatering process, without automated control, and the cyclone and flotation process parameters remained fixed.

[0220] Experimental group: using five embodiments of the present invention (embodiments 1 to 5), gradually optimizing parameters, and conducting comparative experiments.

[0221] Experimental steps:

[0222] Hydrocyclone classification: Hydrocyclone classification was used in both the control group and the experimental group, and the classification efficiency and the distribution of overflow and sand settling products were recorded.

[0223] Copper-sulfur separation flotation: Each group carried out desulfurization flotation and copper-sulfur separation flotation, and recorded the concentrate purity, recovery rate and reagent dosage.

[0224] Phosphorus flotation: Carry out "one roughing, one sweeping and four fines" flotation of phosphate minerals according to the set parameters of each group, and record the purity and recovery rate of the phosphate concentrate.

[0225] Phosphate concentrate dehydration: record the moisture content of the phosphate concentrate after dehydration and the working efficiency of the filter.

[0226] Data Collection:

[0227] Data were collected for each key parameter (concentrate purity, recovery rate, reagent dosage, energy consumption, production time) for all groups.

[0228] Table 1:

[0229]

[0230]

[0231] Experimental summary:

[0232] Through the above comparative experiments, the following conclusions are drawn:

[0233] Improvement of concentrate purity and recovery rate: The process of the present invention, especially in Example 5, optimizes the cyclone classification and flotation process to increase the purity of copper concentrate to 20%, the purity of sulfur concentrate to 24%, and the purity of phosphate concentrate to 30%, which are significantly higher than traditional processes, verifying the advantage of the present invention in concentrate grade.

[0234] Optimization of reagent use efficiency: In the gradual optimization process, the use of reagents in each embodiment of the present invention is gradually reduced. Compared with the 100g / t dosage of the traditional process, Example 5 reduces the dosage of the collector to 75g / t and ensures a higher recovery rate, which shows that the technical solution of the present invention effectively reduces the cost of reagents and improves the economic benefits.

[0235] Energy consumption and production efficiency: The unit energy consumption of the traditional process is 15kWh / t, and the production cycle is about 60 minutes. However, through automated control and parameter optimization, the energy consumption of Example 5 is reduced to 10kWh / t, and the production cycle is shortened to 45 minutes, thereby improving the overall production efficiency and meeting the requirements of energy conservation and consumption reduction.

[0236] The present invention shows significant innovation compared with the traditional process through the gradual optimization of the embodiments. Each embodiment optimizes the process conditions from different angles, achieves a significant improvement in the concentrate purity and recovery rate, and reduces the dosage of reagents, energy consumption and production cycle, verifying the innovation and reliability of the present invention in the process of recovering phosphate minerals from fine tailings.

[0237] On the basis of the above experiments, in order to further explore the potential and optimization space of the process of the present invention, an in-depth research experiment can be designed to explore the influence of process parameters on the recovery effect of phosphate minerals and clarify the optimal parameter range. The experiment aims to optimize the parameter combination to maximize the concentrate purity and recovery rate, and further enhance the application value of the present invention.

[0238] Study design:

[0239] Purpose:

[0240] The experiment aims to systematically adjust key process parameters (such as slurry concentration, pH value, collector dosage, frother dosage, cyclone pressure, etc.) to study the influence of different parameters on the purity, recovery rate, energy consumption, production cycle, etc. of phosphate mineral concentrate, so as to obtain the optimal process parameter combination and further improve the recovery efficiency and product quality of the process.

[0241] Experimental design overview:

[0242] Through multi-factor experimental design methods (such as orthogonal experimental design or response surface methodology), a series of experimental groups are designed to compare different parameter combinations to identify the parameters with the most significant recovery effect and their optimal values. The experiment mainly focuses on the following key factors:

[0243] Slurry concentration, pH value, collector dosage, frother dosage, cyclone working pressure

[0244] Experimental materials and equipment:

[0245] Materials: The same batch of fine-grained iron ore tailings samples, with a phosphorus content of 3%-3.5% and a copper content of 0.04%-0.07%.

[0246] Equipment: cyclone, flotation machine, disc filter, automatic control system, pH adjustment system, liquid level and foam layer sensor, etc.

[0247] Experimental steps:

[0248] Determine the scope and classification of experiments;

[0249] Determine the experimental range for each parameter:

[0250] Slurry concentration: 2.5%-4%

[0251] pH: 7.5-8.5

[0252] Collector dosage: 30-80g / t

[0253] Foaming agent dosage: 10-35g / t

[0254] Cyclone pressure: 0.3-0.5MPa

[0255] Orthogonal experimental design was used to generate a series of parameter combinations to ensure that the experimental groups with different parameter combinations were uniform and comprehensive.

[0256] Experimental group settings:

[0257] Each set of experiments adjusts one or more parameters, and other parameters are fixed at the baseline level. The design of each set of experimental parameters is shown in the table.

[0258] Experimental process:

[0259] Each experimental group carried out cyclone classification, copper-sulfur separation flotation, phosphorus flotation and phosphate concentrate dehydration according to the set parameter combination.

[0260] After each set of experiments, the following data were recorded:

[0261] Purity and recovery of phosphate concentrate

[0262] Grade and recovery rate of copper concentrate and sulfur concentrate

[0263] Chemical consumption, energy consumption and production time

[0264] Data Analysis:

[0265] Variance analysis or response surface methodology was used to analyze the significance of the impact of various parameters on the recovery of phosphate minerals and to determine the key parameters and optimal values.

[0266] Table 2:

[0267]

[0268] Results and discussion:

[0269] Parameter optimization effect: From the experimental results, it can be seen that with the optimization of slurry concentration, cyclone pressure, pH value and collector dosage, the purity and recovery rate of phosphate concentrate are significantly improved. For example, in experimental group 5, at the highest slurry concentration (4.0%), appropriate pH value (8.3), and appropriate ratio of collector and frother, the purity of phosphate concentrate reached 30.5%, and the phosphorus recovery rate increased to 85%, which is significantly better than other groups.

[0270] Key parameter analysis: According to the results of variance analysis, the cyclone working pressure and pulp concentration have the greatest impact on the purity and recovery rate of phosphate concentrate, followed by collector and pH value, while the amount of frother has a relatively small effect on the selective flotation of phosphate minerals. This shows that the adjustment of cyclones and pulp concentration is crucial in the recovery process.

[0271] Optimal parameter combination: Based on the experimental results and data analysis, the optimal parameter combination was obtained: slurry concentration 4.0%, pH value 8.3, collector dosage 70g / t, frother dosage 20g / t, cyclone working pressure 0.45MPa. Under this parameter combination, the purity and recovery rate of phosphate concentrate are the highest, while the reagent consumption and energy consumption are the lowest, and the process efficiency is the best.

[0272] Experimental summary:

[0273] This study experimentally verified that the purity and recovery rate of phosphate mineral recovery can be significantly improved by finely adjusting the process parameters. The determination of the optimal parameter combination provides a further optimization direction for the process of the present invention, making it more competitive and valuable in the field of phosphate mineral recovery. This study not only demonstrates the innovativeness of the process of the present invention, but also proves its advantages in energy saving and consumption reduction, and improving resource utilization, meeting the needs of green production.

[0274] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for recovering phosphate minerals from fine-grained tailings, characterized in that: The following steps are involved: Hydrocyclone classification: The fine-grained slurry is introduced into the hydrocyclone for classification, the overflow product enters the overflow pipe, and the sedimentation product enters the subsequent desulfurization flotation process; Copper-sulfur separation flotation: The crude copper concentrate obtained after desulfurization is dehydrated and then enters the copper-sulfur separation flotation process to separate copper concentrate and sulfur concentrate; Phosphorus flotation process: The desulfurized minerals enter the fine-grained phosphorus selection process, using a one-roughing, one-sweeping and four-fine flotation process to select the phosphate concentrate, and the rest is discharged as tailings; Dehydration of phosphate concentrate: The phosphate concentrate is sent to the disc filter for dehydration to obtain the final phosphate concentrate powder.

2. The method for recovering phosphate minerals from fine tailings according to claim 1, characterized in that: The cyclone classification specifically comprises the following steps: Slurry preparation: adjust the slurry concentration of fine iron ore tailings to 2-4%, the copper grade mass percentage in the ore sample should be controlled between 0.04%-0.07%, and the phosphorus grade mass percentage should be between 3%-3.5%; Entering the inclined plate for grading and impurity removal: The slurry first enters the inclined plate for classification, and the overflow port of the inclined plate discharges the finer-grained minerals; Install a screen with a pore size of 1-2mm at the overflow outlet of the inclined plate to remove large particles of impurities; Cyclone classification operation: After the impurities are removed by the inclined plate, the slurry enters the cyclone for further classification. The working pressure of the cyclone is controlled at 0.2-0.4MPa; The overflow product flows into the overflow pipe by gravity; The sedimentation product enters the desulfurization flotation process.

3. The method for recovering phosphate minerals from fine-grained tailings according to claim 2, characterized in that: The particle size range parameters in the slurry preparation step are: D50=6.862 μm; D75=16.00 μm; D90=29.47 μm; D97=49.54 μm.

4. The method for recovering phosphate minerals from fine tailings according to claim 1, characterized in that: The copper-sulfur separation flotation specifically comprises the following steps: Desulfurization flotation: send the sedimentation product pulp into the desulfurization flotation tank, adjust the pulp pH value to 7.5-8.5, add an appropriate amount of collector, and perform a flotation; Dehydration treatment: The desulfurized crude copper concentrate is initially dehydrated to adjust the pulp concentration to 30-40% in preparation for subsequent copper-sulfur separation and flotation; Copper-sulfur separation flotation: The dehydrated pulp is sent to the copper-sulfur separation flotation process, the pH value is adjusted to 8.0-8.5, the amount of collector is controlled at 50-80g / t, and the copper concentrate is selectively floated; Sulfur concentrate and copper concentrate are obtained by separation and collection, with the copper grade controlled at more than 15% and the sulfur grade at more than 20%.

5. The method for recovering phosphate minerals from fine-grained tailings according to claim 4, characterized in that: The collector for desulfurization flotation is xanthate, and the concentration is controlled at 20-40 g / t.

6. The method for recovering phosphate minerals from fine tailings according to claim 1, characterized in that: The phosphorus flotation process specifically includes the following steps: Phosphorus flotation process: Phosphate minerals are recovered through flotation process, which adopts "one roughing, one sweeping and four fines": Automation control: Use automated equipment to control the flotation liquid level at 2-5 cm; During the flotation process, a foam layer thickness sensor and an automatic adjustment system are used to achieve automatic control of flotation; Tailings discharge: Phosphate tailings enter the tailings pond through the tailings pipeline.

7. The method for recovering phosphate minerals from fine tailings according to claim 1, characterized in that: The specific steps of one rough, one sweep and four fine are as follows: First roughing: adding collector and frother, the collector dosage is 50-70g / t, the frother dosage is 20-30g / t, so as to make the phosphate minerals initially enriched in the roughing; One sweep: further remove impurities and minerals, and maintain the pH value at 8.0-8.5; Four concentrate flotation steps: four concentrate flotation steps are carried out, and each step uses precisely adjusted collector and frother concentrations to gradually enrich the phosphate concentrate to the required purity.

8. The method for recovering phosphate minerals from fine tailings according to claim 7, characterized in that: The four steps of flotation of the concentrated ore are as follows: First concentrate flotation: Collector: Use fatty acid collector, the concentration is controlled at 30-40g / t; Frothing agent: Use methyl isobutyl carbinol as foaming agent, with a concentration of 10-15g / t; Slurry pH value: adjusted to 7.5-8.0; Flotation time: controlled at 5-7 minutes to obtain initially enriched phosphate concentrate; Second concentrate flotation: Collector concentration adjustment: reduce collector concentration to 25-35g / t; Adjustment of foaming agent concentration: maintain at 8-12g / t; Slurry pH value: fine-tuned to 8.0-8.5; Flotation time: shortened to 4-6 minutes, rapid capture of phosphate minerals; The third concentrate flotation: Collector concentration is further reduced: to 20-30g / t; Frothing agent concentration maintenance: maintain 8-10g / t; Slurry pH value: maintained at 8.0-8.5; Flotation time: 3-5min, further enriching phosphorus minerals; The fourth concentrate flotation: Collector fine-tuning: down to 15-25g / t; Foaming agent: controlled at 5-8g / t; Slurry pH value: maintained at 8.0-8.5; Flotation time: 3-4 minutes, to complete the final enrichment of phosphate minerals and obtain high-purity phosphate concentrate.

9. The method for recovering phosphate minerals from fine tailings according to claim 1, characterized in that: The phosphate concentrate dehydration specifically comprises the following steps: Disc filter filtration: The phosphate concentrate obtained by four-fine flotation is sent to the disc filter for dehydration. The working pressure of the filter is set at 0.2-0.3MPa, and finally the phosphate concentrate with a solid water content of 10% to 15% is obtained; Automatic cake unloading: Use the automatic cake unloading function of the filter to unload the solids. The cake unloading cycle of the filter should be controlled within 10-15 minutes; Final product: Dehydrated phosphorus concentrate with a phosphorus grade of 28%-30%, which is a high-purity phosphorus mineral that meets product standards.

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