Method for reducing phosphorus in high-phosphorus titanium concentrate

Abstract

The present application relates to a method for reducing phosphorus content of high-phosphorus titanium concentrate, and belongs to the technical field of mineral processing. The method comprises the following steps: step one, mixing the high-phosphorus titanium concentrate with water to obtain a slurry or directly using the slurry of the titanium concentrate produced in the last step of the flotation production of titanium concentrate; step two, mixing the slurry obtained in step one with acid to obtain an acid-containing slurry; step three, washing and filtering the acid-containing slurry obtained in step two with water to obtain a titanium concentrate with a P content of less than 0.025% and wastewater; step four, neutralizing the wastewater obtained in step three with lime to remove residues in the wastewater, obtaining residue-free wastewater, which is continuously used in step one. The method has the advantages of simple process, phosphorus removal rate of more than 75%, phosphorus content of the titanium concentrate after phosphorus removal of less than 0.025%, titanium concentrate loss rate of less than 1%, full utilization of waste acid, low phosphorus removal cost, environmental protection, and low requirement for equipment.

Description

Technical Field

[0001] This invention belongs to the field of mineral processing technology, specifically relating to a method for reducing phosphorus in high-phosphorus titanium concentrate. Background Technology

[0002] my country's Panzhihua region is rich in titanium resources, with Panzhihua being a major titanium-producing area. However, titanium deposits generally contain phosphorus, with the phosphorus content in titanium concentrate ranging from 0.03% to 0.15% after beneficiation. Excessive phosphorus content in titanium concentrate can lead to problems such as deteriorated performance of the produced metallic titanium and alloys, lower whiteness of the produced titanium dioxide, and easy cracking of welds in synthesized solders during use. The standard for phosphorus content in titanium concentrate is generally less than 0.03%.

[0003] Currently, phosphorus removal from titanium concentrate generally employs methods such as reverse flotation, high-concentration selective acid leaching, and the addition of inhibitors during flotation. These methods suffer from drawbacks including high reagent costs, severe equipment corrosion, unsatisfactory phosphorus removal effects, and high wastewater treatment costs. Therefore, developing an efficient, low-cost, and environmentally friendly dephosphorization method for high-phosphorus titanium concentrate is of great significance. Summary of the Invention

[0004] The purpose of this invention is to provide an efficient, low-cost, and environmentally friendly method for reducing phosphorus content in high-phosphorus titanium concentrate, so that the phosphorus content of the high-phosphorus titanium concentrate is less than 0.025%.

[0005] To achieve the above objectives, the specific technical solution of the present invention is as follows:

[0006] Step 1: Mix the high-phosphorus titanium concentrate with water to obtain a slurry, or directly use the titanium concentrate slurry produced in the final step of flotation titanium concentrate production;

[0007] Step 2: Mix the slurry obtained in Step 1 with acid to obtain an acid-containing slurry;

[0008] Step 3: Wash and filter the acidic slurry obtained in Step 2 with water to obtain titanium concentrate with a P content of less than 0.025% and wastewater;

[0009] Step 4: Neutralize the wastewater obtained in Step 3 with lime to remove the residue in the wastewater and obtain residue-free wastewater, which is then used in Step 1.

[0010] Furthermore, in step one, the mass fraction of high-phosphorus titanium concentrate in the slurry is 30%-70%;

[0011] Furthermore, in step two, the acid is waste sulfuric acid, hydrochloric acid, or concentrated sulfuric acid produced by a titanium dioxide plant;

[0012] Furthermore, in step two, the concentration of the acid is 15%-98%;

[0013] Furthermore, in step two, the pH of the acidic slurry is 0.5-3.0;

[0014] Furthermore, in step three, the mass ratio of water to acidic slurry is 1:10-30.

[0015] In step two, the slurry obtained in step one is mixed with acid to obtain an acidic slurry. The concentration of the acid is 15%-98%, and the pH value of the acidic slurry is 0.5-3.0 because the phosphorus in the titanium concentrate is mainly found in apatite—CaO. 10 In (PO4)6CO3, apatite can generate calcium dihydrogen phosphate in solution under acidic conditions. The chemical reaction formula is Ca... 10 (PO4)6CO3 + 12H + = 3Ca(H2PO4)2 + 7Ca 2+ +CO3 2- In selective leaching, the acid concentration directly affects the rate and extent of phosphate mineral decomposition, as well as the recovery rate of titanium concentrate. If the acidity is too low, the phosphate removal effect is poor; if the acid concentration is too high, the loss of titanium concentrate is significant. Therefore, it is necessary to control the acidity of the reaction system within a certain range.

[0016] In step three, the acidic slurry obtained in step two is washed and filtered with water to remove free sulfate ions from the acidic slurry, ensuring that the quality of the titanium concentrate product meets the requirements.

[0017] The beneficial effects of this invention are: This invention obtains low-phosphorus, high-quality titanium concentrate from high-phosphorus titanium concentrate through acid washing and filtration. This dephosphorization method is simple, achieving a dephosphorization rate of over 75%, reducing the phosphorus content of the dephosphorized titanium concentrate to below 0.025%, and reducing the titanium concentrate loss rate to less than 1%. This method fully utilizes waste acid, resulting in low dephosphorization costs, environmental friendliness, and minimal equipment requirements. Detailed Implementation

[0018] The present invention will be described in detail below through embodiments. It should be understood that the following embodiments are for illustrative purposes only and do not limit the scope of the present invention in any way.

[0019] Example 1

[0020] The method for reducing phosphorus in high-phosphorus titanium concentrate involves the following steps:

[0021] Five tons of high-phosphorus titanium concentrate with a TiO2 content of 47.11% and a P content of 0.103% by mass were selected.

[0022] Step 1: Mix high-phosphorus titanium concentrate with 4.1m 3 Water is mixed to form a slurry, in which the mass fraction of high-phosphorus titanium concentrate is 55%;

[0023] Step 2: Add 96 kg of 21% sulfuric acid produced by the titanium dioxide plant to the slurry obtained in Step 1, and stir thoroughly for 5 minutes to obtain an acidic slurry with a pH of 1.0.

[0024] Step 3: The acidic slurry obtained in Step 2 is washed and filtered with water on a vacuum filter to obtain titanium concentrate and wastewater. The amount of water used for washing and filtration is 920L.

[0025] Step 4: Neutralize the wastewater generated in Step 3 with lime, and then remove the residue from the wastewater to obtain residue-free wastewater, which is then used in Step 1.

[0026] Test results show that the dephosphorization rate of the titanium concentrate obtained after the above treatment can reach 82.5%, and the phosphorus content of the dephosphorized titanium concentrate is 0.018%, which meets the domestic requirements for high-quality titanium concentrate. Meanwhile, the titanium concentrate loss rate is 1%, and the titanium concentrate grade is increased by 0.1%.

[0027] Example 2

[0028] The method for reducing phosphorus in high-phosphorus titanium concentrate involves the following steps:

[0029] Five tons of high-phosphorus titanium concentrate with a TiO2 content of 47.11% and a P content of 0.103% by mass were selected.

[0030] Step 1: Mix high-phosphorus titanium concentrate with 4.1m 3 Water is mixed to form a slurry, in which the mass fraction of high-phosphorus titanium concentrate is 55%;

[0031] Step 2: Add 10.5 kg of 21% sulfuric acid produced by the titanium dioxide plant to the slurry obtained in Step 1, and stir thoroughly for 10 minutes to obtain an acidic slurry with a pH of 2.0.

[0032] Step 3: The acidic slurry obtained in Step 2 is washed and filtered with water on a vacuum filter to obtain titanium concentrate and wastewater. The amount of water used for washing and filtration is 920L.

[0033] Step 4: Neutralize the wastewater generated in Step 3 with lime, and then remove the residue from the wastewater to obtain residue-free wastewater, which is then used in Step 1.

[0034] Test results show that the dephosphorization rate of the titanium concentrate obtained after the above treatment can reach 75.7%, and the phosphorus content of the dephosphorized titanium concentrate is 0.025%, which meets the domestic requirements for high-quality titanium concentrate. Meanwhile, the titanium concentrate loss rate is 0.87%, and the titanium concentrate grade is increased by 0.08%.

[0035] Example 3

[0036] The method for reducing phosphorus in high-phosphorus titanium concentrate involves the following steps:

[0037] 80 tons of high-phosphorus titanium concentrate with a TiO2 content of 47.01% and a P content of 0.101% by mass fraction were selected.

[0038] Step 1: Mix high-phosphorus titanium concentrate with 65.5m 3 Water is mixed to form a slurry, in which the mass fraction of high-phosphorus titanium concentrate is 55%;

[0039] Step 2: Add 1440 kg of 21% sulfuric acid from the titanium dioxide plant to the slurry obtained in Step 1, and stir thoroughly for 5 minutes to obtain an acidic slurry with a pH of 1.0.

[0040] Step 3: The acidic slurry obtained in Step 2 is washed and filtered with water on a vacuum filter to obtain titanium concentrate and wastewater. The amount of water used for washing and filtration is 8000L.

[0041] Step 4: Neutralize the wastewater generated in Step 3 with lime, and then remove the residue from the wastewater to obtain residue-free wastewater, which is then used in Step 1.

[0042] Test results show that the dephosphorization rate of the titanium concentrate obtained after the above treatment can reach 83.2%, and the phosphorus content of the dephosphorized titanium concentrate is 0.017%, which meets the domestic requirements for high-quality titanium concentrate. Meanwhile, the titanium concentrate loss rate is 0.91%, and the titanium concentrate grade is increased by 0.08%.

Claims

1. A method for reducing phosphorus in high-phosphorus titanium concentrate, characterized by: The following steps are used to process high-phosphorus titanium concentrate with a Ti content of 45%-48% and a P content of 0.04%-0.5% by mass fraction into titanium concentrate with a P content of less than 0.025%: Step 1: Mix the high-phosphorus titanium concentrate with water to obtain a slurry, or directly use the titanium concentrate slurry produced in the final cleaning step of flotation titanium concentrate production; the mass fraction of high-phosphorus titanium concentrate in the slurry is 55%; Step 2: Mix the slurry obtained in Step 1 with acid to obtain an acid-containing slurry; the acid is waste sulfuric acid, hydrochloric acid, or concentrated sulfuric acid produced by a titanium dioxide plant, and the concentration of the acid is 21%; the pH of the acid-containing slurry is 1.0-2.0; Step 3: Wash and filter the acidic slurry obtained in Step 2 with water to obtain titanium concentrate with a P content of less than 0.025% and wastewater; the mass ratio of water to acidic slurry is 1:10-30. Step 4: Neutralize the wastewater obtained in Step 3 with lime to remove the residue in the wastewater and obtain residue-free wastewater, which is then used in Step 1.