A method for recovering quartz and calcite from tailings

Abstract

This invention discloses a method for recovering quartz and calcite from tailings, comprising the following steps: Step 1) using a preliminary flotation collector to perform preliminary calcite flotation on the tailings, obtaining calcite rough concentrate and preliminary flotation tailings; Step 2) adding an activator containing sulfides and lead salts to the preliminary flotation tailings, and using an enhanced flotation collector to perform enhanced calcite flotation on the preliminary flotation tailings, obtaining quartz rough concentrate. The method for recovering quartz and calcite from tailings provided by this invention uses sulfides and lead salts to activate calcite, and performs enhanced calcite flotation on the preliminary flotation tailings, removing calcite that is difficult to float in the preliminary flotation, thus reducing the calcite content in the quartz product.

Description

Technical Field

[0001] This invention relates to the field of tailings utilization, and more specifically to a method for recovering quartz and calcite from tailings. Background Technology

[0002] With the continuous development of the mining industry, the resulting environmental and resource pressures are increasing, and the disposal and treatment of tailings have become a constraint on the development of mining enterprises. Therefore, how to make good use of mine tailings and improve the comprehensive utilization level of tailings is of profound significance for alleviating resource pressure, achieving environmental governance, and cultivating new economic growth points for mining enterprises.

[0003] The main components of tailings from some sulfide mines are calcite and quartz. The comprehensive utilization of these tailings primarily involves the separation and recovery of calcite and quartz. Currently, for the separation of quartz and calcite, the raw materials are mostly quartz sand or mineral raw materials with high quartz content, mainly using two methods: one is to inhibit quartz flotation of calcite, and the other is to inhibit calcite flotation of quartz. However, existing processes for processing mine tailings suffer from incomplete separation of quartz and calcite, resulting in high content of both in the products and an inability to simultaneously obtain high-purity quartz and calcite products. Summary of the Invention

[0004] This invention proposes a method for recovering quartz and calcite from tailings. This method optimizes the separation of calcite and quartz, and can simultaneously obtain high-purity quartz and calcite products, thereby improving the comprehensive utilization efficiency of tailings resources. The technical solution adopted in this invention is as follows:

[0005] A method for recovering quartz and calcite from tailings includes the following steps:

[0006] Step 1) Use a preliminary flotation collector to perform preliminary calcite flotation on the tailings to obtain calcite rough concentrate and preliminary flotation tailings;

[0007] Step 2) Add an activator containing sulfides and lead salts to the preliminary flotation tailings, and use an enhanced flotation collector to perform calcite enhanced flotation on the preliminary flotation tailings to obtain quartz rough concentrate.

[0008] After the initial flotation of calcite using fatty acid collectors, a small amount of calcite that is difficult to float remains in the flotation tailings. Since the solubility product of calcium carbonate is 3.36 × 10⁻⁶... -9 The solubility product of lead carbonate is 7.4 × 10⁻⁶. -14 The solubility product of lead sulfide is 8*10. -28 After adding lead salts and sodium sulfide to the flotation system, the following reaction occurs on the surface of calcite:

[0009] CaCO3]CaCO3+Pb 2+=CaCO3]PbCO3+Ca 2+

[0010] CaCO3]PbCO3+S 2- =CaCO3]PbS+CO3 2-

[0011] The above reaction generates lead sulfide minerals on the surface of calcite. These minerals have better floatability than calcium carbonate, thus improving the floatability of calcium carbonate minerals. Based on this, by adding enhanced flotation collectors, synergistic adsorption occurs on the calcite surface, thereby enabling the floatable calcite, which is difficult to float, to achieve enhanced flotation.

[0012] Optionally, the tailings are tailings slurry that has undergone desliming treatment.

[0013] Optionally, the tailings are deslimed and then subjected to preliminary flotation, with the tailings slurry having a mass concentration of 35-45% after desliming.

[0014] Optionally, the method further includes grinding and scrubbing the quartz rough concentrate, and then desliming the ground and scrubbed quartz rough concentrate.

[0015] Optionally, the method further includes magnetic separation of the deslimed quartz concentrate to obtain quartz products.

[0016] Optionally, the method further includes using water glass to refine the calcite rough concentrate.

[0017] Even after enhanced flotation, a small amount of calcite remains in the quartz rough concentrate, which is difficult to remove by flotation alone. Because calcite has perfect cleavage, it is more prone to becoming muddy during grinding. The difference in cleavage properties between calcite and quartz can be used to grind and scrub the quartz flotation rough concentrate. Calcite particles are more easily muddyed, becoming fine mineral particles that can be removed through classification, thereby further reducing the calcium content in the quartz product. Specifically, the grinding and scrubbing process uses a vertical mill with ceramic balls as the grinding media. The grinding process is mainly based on stripping. The material after grinding and scrubbing is then classified and deslimed using a hydrocyclone to remove the fine particles. The underflow is treated with a high-intensity magnetic separator to remove iron-containing substances. The tailings from the high-intensity magnetic separation are the final quartz product.

[0018] Optionally, in the grinding and scrubbing process: the grinding media are ceramic balls, the slurry mass concentration is 30-70%, the volume ratio of slurry to grinding media is 1-3:1, and the grinding and scrubbing time is 5-15 min.

[0019] Optionally, water glass is used to perform three beneficiation processes on the calcite rough concentrate. The amount of water glass used in the first beneficiation is 100-1500 g / t, the amount of water glass used in the second beneficiation is 100-500 g / t, and the amount of water glass used in the third beneficiation is 100-300 g / t.

[0020] Optionally, in step one), the preliminary flotation collector may be a fatty acid-based collector.

[0021] Optionally, the fatty acid collector is selected from at least one of sodium oleate, tal oil, and oxidized paraffin soap.

[0022] Optionally, the preliminary flotation in step one) adopts a two-stage flotation. The amount of preliminary flotation collector used in the first stage of preliminary flotation is 100-400 g / t, and the amount of preliminary flotation collector used in the second stage of preliminary flotation is 50-200 g / t.

[0023] Optionally, during the enhanced flotation process of calcite, the pH of the pulp is 7 to 9.

[0024] Optionally, the sulfide is selected from at least one of sodium sulfide and sodium hydrosulfide.

[0025] Optionally, the lead salt is lead nitrate.

[0026] Optionally, the enhanced flotation collector in step two) may be a fatty acid collector and an advanced xanthate collector.

[0027] Optionally, the fatty acid collector is selected from at least one of sodium oleate, tal oil, and oxidized paraffin soap.

[0028] The advanced xanthate collector is selected from at least one of pentyl xanthate, isopentyl xanthate, and sec-octyl xanthate.

[0029] Optionally, the amount of fatty acid collector added in the enhanced flotation is 100-300 g / t.

[0030] Optionally, the amount of advanced xanthate collector added in the enhanced flotation is 50-150 g / t.

[0031] The technical solution of this invention has the following advantages:

[0032] 1. The method for recovering quartz and calcite from tailings provided by the present invention uses sulfides and lead salts to activate calcite, and performs enhanced calcite flotation on the preliminary flotation tailings, which removes calcite that is difficult to float in the preliminary flotation and significantly reduces the calcite content in the quartz product.

[0033] 2. The method for recovering quartz and calcite from tailings provided by the present invention utilizes the cleavage properties of calcite and employs a process of peeling, grinding, washing, and desliming to remove calcite that is difficult to remove by flotation, thereby further reducing the calcite content in the quartz product and improving the purity of the quartz product. Attached Figure Description

[0034] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0035] Figure 1 This is a process flow diagram of an embodiment of the present invention. Detailed Implementation

[0036] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0037] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0038] Example 1

[0039] In this embodiment, the tailings from the sulfide ore beneficiation process contain 60% quartz and 20% calcite. First, a hydrocyclone is used for desliming, with a desliming yield of 15%. The slurry concentration after desliming is 35%.

[0040] Sodium carbonate was used to adjust the pH of the slurry to 8.5 for preliminary flotation of calcite. The preliminary flotation consisted of two stages, using sodium oleate as the collector. The dosage of sodium oleate in the two stages was 200 g / t and 100 g / t, respectively. The preliminary flotation concentrate and preliminary flotation tailings were obtained. The preliminary flotation concentrate is the calcite rough concentrate.

[0041] Calcite crude concentrate was treated with water glass as a quartz inhibitor and then subjected to three cleaning processes. The water glass dosage for the three cleaning processes was 300 g / t, 200 g / t, and 100 g / t, respectively. After the third cleaning concentrate was subjected to magnetic separation, calcite product was obtained. The magnetic separation magnetic field strength was 1.8 T.

[0042] Lead nitrate (100 g / t), sodium sulfide (300 g / t), sodium oleate (100 g / t), and pentyroxanthate (50 g / t) were added to the preliminary flotation tailings for enhanced flotation. Enhanced flotation yielded a rough quartz concentrate. Analysis showed that the silica content in the rough quartz concentrate was 93.5%.

[0043] Quartz rough concentrate was ground and scrubbed using a vertical mill with ceramic balls as the grinding media. The quartz rough concentrate slurry concentration was 45%, and the volume ratio of slurry to grinding media was 2:1. The grinding and scrubbing time was 10 minutes. After scrubbing, the material was deslimed in a hydrocyclone. The underflow from the hydrocyclone was subjected to strong magnetic separation to remove magnetic materials, thus obtaining the quartz product. The magnetic field strength was 1.8T.

[0044] Testing revealed that the final product obtained in this embodiment was a calcite product with a calcium carbonate content of 90% and a quartz product with a silica content of 95%.

[0045] Example 2

[0046] In this embodiment, the tailings from the sulfide ore beneficiation process contain 50% quartz and 25% calcite. First, a hydrocyclone is used for desliming, with a desliming yield of 25%. The slurry concentration after desliming is 38%.

[0047] Sodium carbonate was used to adjust the pH of the slurry to 9 for preliminary flotation of calcite. The preliminary flotation was divided into two stages, using sodium oleate as the collector. The dosage of sodium oleate in the two stages was 200 g / t and 150 g / t, respectively. The preliminary flotation concentrate and preliminary flotation tailings were obtained. The preliminary flotation concentrate is the calcite rough concentrate.

[0048] Calcite crude concentrate was treated with water glass as a quartz inhibitor and then subjected to three cleaning processes. The water glass dosage for the three cleaning processes was 400 g / t, 200 g / t, and 150 g / t, respectively. After the third cleaning concentrate was subjected to magnetic separation, calcite product was obtained. The magnetic separation magnetic field strength was 1.8 T.

[0049] The tailings from the initial flotation were treated with enhanced flotation by adding 100 g / t lead nitrate, 300 g / t sodium sulfide, 150 g / t sodium oleate, and 80 g / t pentyroxanthate. The enhanced flotation yielded a rough quartz concentrate. Analysis showed that the silica content in the rough quartz concentrate was 92%.

[0050] Quartz rough concentrate was ground and scrubbed using a vertical mill with ceramic balls as the grinding media. The quartz rough concentrate slurry concentration was 45%, and the volume ratio of slurry to grinding media was 2:1. The grinding and scrubbing time was 10 minutes. After scrubbing, the material was deslimed in a hydrocyclone. The underflow from the hydrocyclone was subjected to strong magnetic separation to remove magnetic materials, thus obtaining the quartz product. The magnetic field strength was 1.8T.

[0051] Testing revealed that the final product obtained in this embodiment contained 91% calcium carbonate and 94% silica.

[0052] Comparative Example 1

[0053] The tailings and treatment methods used in this comparative example are the same as in Example 1. The only difference is that lead nitrate and sodium sulfide are not added in the enhanced flotation step; only 100 g / t of sodium oleate and 50 g / t of pentyroxanthate are used for flotation. Ultimately, only a quartz product with a silica content of 90% can be obtained.

[0054] Comparative Example 2

[0055] The tailings and treatment methods used in this comparative example are the same as in Example 2. The only difference is that lead nitrate and sodium sulfide are not added in the enhanced flotation step; only 150 g / t of sodium oleate and 80 g / t of pentyroxanthate are used for flotation. Ultimately, only a quartz product with a silica content of 88% can be obtained.

[0056] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for recovering quartz and calcite from tailings, characterized in that, Includes the following steps: Step 1) Use a preliminary flotation collector to perform preliminary calcite flotation on the tailings to obtain calcite rough concentrate and preliminary flotation tailings; the preliminary flotation collector is a fatty acid-based collector; Step 2) An activator containing sulfides and lead salts is added to the preliminary flotation tailings, and an enhanced flotation collector is used to perform calcite enhanced flotation on the preliminary flotation tailings to obtain quartz rough concentrate; the sulfides are selected from at least one of sodium sulfide and sodium hydrosulfide; the lead salt is lead nitrate, and the pH of the pulp is 7-9 during the calcite enhanced flotation process; The quartz rough concentrate is ground and scrubbed, and then the ground and scrubbed quartz rough concentrate is deslimed; the deslimed quartz rough concentrate is magnetically separated to obtain quartz products. Water glass was used to refine calcite rough concentrate; The amount of sulfide added to the preliminary flotation tailings is 500~1500g / t; the amount of lead salt added to the preliminary flotation tailings is 100~300g / t. The enhanced flotation collector in step two) includes fatty acid collectors and advanced xanthate collectors; The fatty acid collector is selected from at least one of sodium oleate, tal oil, and oxidized paraffin soap; The advanced xanthate collector is selected from at least one of pentyl xanthate, isopentyl xanthate, and sec-octyl xanthate.

2. The method for recovering quartz and calcite from tailings according to claim 1, characterized in that, In step one), the fatty acid collector is selected from at least one of sodium oleate, tal oil, and oxidized paraffin soap.

3. The method for recovering quartz and calcite from tailings according to claim 1, characterized in that, The amount of fatty acid collector added in the enhanced flotation is 100~300g / t; the amount of advanced xanthate collector added in the enhanced flotation is 50~150g / t.

4. The method for recovering quartz and calcite from tailings according to any one of claims 1 to 3, characterized in that, The tailings are tailings slurry that has undergone desliming treatment.

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