A flotation method for fine-grained cassiterite oxide ore

Abstract

The present invention discloses a flotation method for fine-grained cassiterite oxide ore, which belongs to the field of mineral processing technology. For fine-grained cassiterite oxide ore with extremely fine particle size and high content of mud minerals and iron oxide minerals, which is difficult to select, the method comprises the following steps: 1) re-grinding the fine-grained cassiterite oxide ore to a content of more than 65% of ‑37μm and a flotation pulp concentration of 30‑35%; 2) reducing the sulfur content to less than 1% through a flotation desulfurization process; 3) adding a desludging collector and using flash flotation to remove some of the fine mud. 4) adding a sludge dispersant. 5) adding a mixed collector and an auxiliary collector to float out the tin minerals to obtain a tin concentrate product. The present invention has the advantages of strong adaptability to materials, stable indicators, low dosage of reagents, and high recovery rate, and is an economical and efficient method for flotation recovery of fine-grained cassiterite oxide ore.

Description

Technical Field

[0001] The invention relates to the technical field of mineral processing, in particular to a flotation method for fine-grained cassiterite oxide ore. Background Art

[0002] Cassiterite contains 78.6% tin and is the most common tin mineral and the main tin ore mineral. Due to the large difference in specific gravity between cassiterite and gangue components, gravity separation is the main method for cassiterite separation and has been widely used. Cassiterite has mechanical properties such as high hardness, high density, and brittleness. It is easy to be over-crushed during the grinding process. The use of gravity separation method to recover this part of fine-grained cassiterite has great limitations, resulting in a large amount of tin metal loss. According to statistics, 80% of the tin metal lost in my country is lost from the ore mud. About one-third of the tin ore in the world is lost. It is lost in the form of fine particles, and with the continuous mining of primary tin ore resources, the grade of tin ore is getting lower and lower. Therefore, strengthening the recovery of fine-grained cassiterite is of great significance to improving the recovery and utilization of tin ore resources. Compared with gravity separation, the lower limit of effective recovery particle size of flotation is much lower. In recent years, my country's cassiterite flotation technology has also made certain progress. Yunnan Hualian Zinc and Indium Company, Inner Mongolia Huanggang Mining Company, Yunnan Tin Industry Co., Ltd. and some private concentrators have industrialized the application of cassiterite flotation technology and achieved good separation indicators.

[0003] In cassiterite flotation, fine mud, sulfide and iron minerals are the main factors affecting cassiterite flotation. Before entering cassiterite flotation, it is necessary to do "three removals" as much as possible. In recent years, the cassiterite flotation process has adopted cyclone desliming and flotation desulfurization technology to effectively eliminate the influence of fine mud and sulfide on flotation indicators. However, as the grade of tin ore entering the selection process gradually decreases, the cassiterite crystal size becomes finer and finer, the iron mineral content continues to increase, and the combination of tin and iron becomes closer and closer. The influence of iron oxide minerals represented by hematite / limonite on the flotation indicators of fine-grained cassiterite has gradually become prominent. At present, there is a lack of effective removal / suppression methods for iron oxide minerals: First, the magnetic separation of iron and tin is seriously mixed. Some technicians have conducted a desliming and desulfurization of the cassiterite sulfide ore re-selection mud ore of a certain concentrator. The results showed that with the increase of magnetic field intensity, the yield, grade and recovery rate of iron concentrate increased. However, the product contained a high tin content (the tin grade was close to that of the feed ore) and the tin loss was large (the loss rate was about 50%), resulting in an unsatisfactory iron removal effect. Secondly, the selectivity of the collector was poor. The hydroxamic acid collectors commonly used in cassiterite flotation can undergo a strong complexation reaction with iron oxide minerals to form chelates. These iron oxide minerals floated up into the concentrate product, affecting the concentrate quality and operating efficiency. Finally, the selectivity and practicality of commonly used inhibitors were poor. While inhibiting iron, they also had a strong inhibitory effect on cassiterite. Therefore, there is currently no more effective measure to address the adverse effects of iron minerals on cassiterite flotation.

[0004] Traditionally, mechanical desludging has been performed using equipment such as cyclones and centrifuges to reduce the -10μm fraction. However, this process results in a high metal loss rate, typically between 20-40%. This is particularly true for fine-grained cassiterite oxide ores, where the tin metal is primarily distributed in the -10μm fraction.

[0005] Due to the fine particle size and high mud content of the selected minerals, the foam volume is large and sticky, the foam carries the ore poorly, and it is prone to sludging. Generally, tributyl phosphate is added as an auxiliary collector. Due to its low surface tension and poor solubility in water, it can effectively destabilize the formed foam film, quickly defoaming it and improving the foam viscosity. However, adding tributyl phosphate above a certain dosage will lead to a decrease in recovery rate. At the same time, tributyl phosphate is expensive. If a large amount of tributyl phosphate is added to stabilize the foam, it will not only affect the performance but also increase costs. Summary of the Invention

[0006] (1) Technical problems solved

[0007] In response to the shortcomings of the existing technology, the present invention provides a flotation method for fine-grained cassiterite oxide ore, which adopts new processes and new reagents to reduce the metal loss rate during desliming, improve the capture capacity and selectivity of fine-grained cassiterite of -10μm, and achieve efficient recovery of fine-grained cassiterite oxide ore.

[0008] (2) Technical solution

[0009] To achieve the above object, the present invention provides the following technical solution: a cassiterite oxide ore fine mud flotation method, characterized in that it comprises the following steps:

[0010] 1) Fine-grained cassiterite oxide ore is pre-classified through a hydrocyclone. The mass percentage of the cyclone overflow particles smaller than 37 microns is greater than 65%. Water is added to a mixing barrel to mix the slurry to a concentration of 30-35%. The settled sand is returned to the tower mill for further grinding.

[0011] 2) Add 60-150 g / t of copper sulfate, 80-200 g / t of butyl xanthate, and 30-100 g / t of pine oil to the stirring barrel in step 1), remove sulfur by flotation to reduce the sulfur content to below 1%, and produce sulfur concentrate.

[0012] 3) Add TN-1, a desliming collector, at a dosage of 80-160 g / t to the desulfurized slurry from step 2. Flash flotation is performed to remove the fine mud that easily floats and poses a significant threat to flotation. The fine mud is then discarded. TN-1 is composed of 1-4 parts sodium cetyl sulfonate, 1-4 parts polyoxyethylene stearate, 1-2 parts sodium linoleate, and 1-2 parts sodium petroleum sulfonate.

[0013] 4) adding 150-400 g / t of water glass to the slurry after desliming in step 3) and then placing it into a mixing tank;

[0014] 5) Adding a collector and an auxiliary collector to the stirring tank in step 4) is a collector using sodium hydroxamate with mixed carbon chains in an amount of 500-1000 g / t, and an auxiliary collector using an alcohol ester mixture SN-F prepared from diethyl carbonate and n-nonanol in a ratio of 2:3 in an amount of 150-300 g / t.

[0015] 6) Use a flotation machine to float out the tin minerals to obtain tin concentrate products.

[0016] (3) Beneficial effects

[0017] Compared with the prior art, the present invention provides a flotation method for fine-grained cassiterite oxide ore, which has the following beneficial effects:

[0018] 1) Using the desludging collector TN-1, which has excellent permeability, dispersibility, and selectivity, through flash flotation desludging, metal loss can be controlled below 5%. This removes some of the -5μm fine mud that is easily floated and poses a significant threat to flotation, particularly due to its low tin content. Compared to mechanical desludging processes, this significantly reduces metal loss.

[0019] 2) By adding a relatively low amount of water glass, a slime dispersant, the surface charge of the mineral particles is enhanced, increasing the repulsive force between the particles, preventing agglomeration, reducing slime contamination of the mineral surface, and increasing the contact between the cassiterite surface and the collector. This not only enhances the collection effect, but also reduces the amount of fine slime carried by the foam and improves foam viscosity.

[0020] 3) The collector uses sodium hydroxamate with mixed carbon chains. The length of the carbon chain promotes the complementary effect between them, making the adsorption of the mixed agent on the mineral surface more uniform, enhancing the adhesion between the mineral particles and the bubbles, thereby improving and enhancing the effect of the flotation process.

[0021] 4) Using an alcohol-ester mixture as an auxiliary collector instead of traditional tributyl phosphate improves froth viscosity while enhancing the collection effect, thereby increasing recovery. Even excessive addition does not reduce recovery, improving the adaptability of the overall flotation process.

[0022] 5) Compared with existing technologies, the flotation method for fine-grained cassiterite oxide ore provided by this invention increases tin concentrate recovery by 15-20%, improves tin concentrate grade by 10-15%, and reduces reagent costs by 40%. This method offers advantages such as strong material adaptability, stable foam, low reagent usage, and high recovery rates. It is a low-carbon, environmentally friendly, and cost-effective method for flotation recovery of fine-grained cassiterite. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0025] Example 1:

[0026] The processing object of this embodiment is a tin mine in Yunnan. The raw ore contains 1.0%-1.5% tin, about 2% sulfur, and 35%-40% iron. The main iron-containing mineral is limonite. The steps are as follows:

[0027] 1) Fine-grained cassiterite oxide ore is pre-classified through a hydrocyclone. The mass percentage of the cyclone overflow particles smaller than 37 microns is greater than 65%. Water is added to a mixing barrel to mix the slurry to a concentration of 30-35%. The settled sand is returned to the tower mill for further grinding.

[0028] 2) Add 80 g / t of copper sulfate, 100 g / t of butyl xanthate, and 50 g / t of pine oil to the stirring barrel of step 1), remove sulfur by flotation to reduce the sulfur content to below 0.5%, and produce sulfur concentrate.

[0029] 3) Add desludging collector TN-1 to the desulfurized slurry in step 2) at a dosage of 100 g / t, and use a flash flotation to remove some fine mud that is easy to float and poses a greater threat to flotation. The fine mud is directly discarded.

[0030] 4) adding 300 g / t of water glass to the slurry after desliming in step 3) and then placing it into a mixing tank;

[0031] 5) Adding a collector and an auxiliary collector to the stirring barrel of step 4) , the collector is a mixed carbon chain sodium hydroxamate, the amount is 700g / t, the auxiliary collector is a diethyl carbonate: n-nonanol = 2:3 configuration of the alcohol ester mixture SN-F, the amount is 200g / t.

[0032] 6) Use a flotation machine to float out the tin ore to obtain a tin concentrate product, with a final concentrate grade of about 5% and a comprehensive recovery rate of more than 75%.

[0033] The beneficial effects of the present invention are:

[0034] 1) Using the desludging collector TN-1, which has excellent permeability, dispersibility, and selectivity, through flash flotation desludging, metal loss can be controlled below 5%. This removes some of the -5μm fine mud that is easily floated and poses a significant threat to flotation, particularly due to its low tin content. Compared to mechanical desludging processes, this significantly reduces metal loss.

[0035] 2) By adding a relatively low amount of water glass, a slime dispersant, the surface charge of the mineral particles is enhanced, increasing the repulsive force between the particles, preventing agglomeration, reducing slime contamination of the mineral surface, and increasing the contact between the cassiterite surface and the collector. This not only enhances the collection effect, but also reduces the amount of fine slime carried by the foam and improves foam viscosity.

[0036] 3) The collector uses sodium hydroxamate with mixed carbon chains. The length of the carbon chain promotes the complementary effect between them, making the adsorption of the mixed agent on the mineral surface more uniform, enhancing the adhesion between the mineral particles and the bubbles, thereby improving and enhancing the effect of the flotation process.

[0037] 4) Using an alcohol-ester mixture as an auxiliary collector instead of traditional tributyl phosphate improves froth viscosity while enhancing the collection effect, thereby increasing recovery. Even excessive addition does not reduce recovery, improving the adaptability of the overall flotation process.

[0038] 5) Compared with existing technologies, the flotation method for fine-grained cassiterite oxide ore provided by this invention increases tin concentrate recovery by 15-20%, improves tin concentrate grade by 10-15%, and reduces reagent costs by 40%. This method offers advantages such as strong material adaptability, stable foam, low reagent usage, and high recovery rates. It is a low-carbon, environmentally friendly, and cost-effective method for flotation recovery of fine-grained cassiterite.

[0039] Example 2:

[0040] The processing object of this embodiment is a tin mine in Yunnan. The raw ore contains 0.3%-0.5% tin, 1%-4% sulfur, and about 10% iron. The main iron-containing minerals are hematite and limonite. The steps are as follows:

[0041] 1) Fine-grained cassiterite oxide ore is pre-classified through a hydrocyclone. The mass percentage of the cyclone overflow particles smaller than 37 microns is greater than 65%. Water is added to a mixing barrel to mix the slurry to a concentration of 30-35%. The settled sand is returned to the tower mill for further grinding.

[0042] 2) Add 100 g / t of copper sulfate, 150 g / t of butyl xanthate, and 60 g / t of pine oil to the stirring barrel of step 1), remove sulfur by flotation to reduce the sulfur content to below 0.5%, and produce sulfur concentrate.

[0043] 3) Add desludging collector TN-1 to the desulfurized slurry in step 2) at a dosage of 80 g / t, and use a flash flotation to remove some fine mud that is easy to float and poses a greater threat to flotation. The fine mud is directly discarded.

[0044] 4) adding 200 g / t of water glass to the slurry after desliming in step 3) and then placing it into a mixing tank;

[0045] 5) Adding a collector and an auxiliary collector to the stirring barrel of step 4) , the collector is sodium hydroxamate with mixed carbon chains, the amount is 400g / t, and the auxiliary collector is SN-F, an alcohol ester mixture composed of diethyl carbonate and n-nonanol in a ratio of 2:3, the amount is 100g / t.

[0046] 6) Use a flotation machine to float out the tin ore to obtain a tin concentrate product with a final concentrate grade of 7%-10% and a comprehensive recovery rate of more than 75%.

[0047] The beneficial effects of the present invention are:

[0048] 1) Using the desludging collector TN-1, which has excellent permeability, dispersibility, and selectivity, through flash flotation desludging, metal loss can be controlled below 5%. This removes some of the -5μm fine mud that is easily floated and poses a significant threat to flotation, particularly due to its low tin content. Compared to mechanical desludging processes, this significantly reduces metal loss.

[0049] 2) By adding a relatively low amount of water glass, a slime dispersant, the surface charge of the mineral particles is enhanced, increasing the repulsive force between the particles, preventing agglomeration, reducing slime contamination of the mineral surface, and increasing the contact between the cassiterite surface and the collector. This not only enhances the collection effect, but also reduces the amount of fine slime carried by the foam and improves foam viscosity.

[0050] 3) The collector uses sodium hydroxamate with mixed carbon chains. The length of the carbon chain promotes the complementary effect between them, making the adsorption of the mixed agent on the mineral surface more uniform, enhancing the adhesion between the mineral particles and the bubbles, thereby improving and enhancing the effect of the flotation process.

[0051] 4) Using an alcohol-ester mixture as an auxiliary collector instead of traditional tributyl phosphate improves froth viscosity while enhancing the collection effect, thereby increasing recovery. Even excessive addition does not reduce recovery, improving the adaptability of the overall flotation process.

[0052] 5) Compared with existing technologies, the flotation method for fine-grained cassiterite oxide ore provided by this invention increases tin concentrate recovery by 15-20%, improves tin concentrate grade by 10-15%, and reduces reagent costs by 40%. This method offers advantages such as strong material adaptability, stable foam, low reagent usage, and high recovery rates. It is a low-carbon, environmentally friendly, and cost-effective method for flotation recovery of fine-grained cassiterite.

[0053] While 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 these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A flotation method for fine-grained cassiterite oxide ore, characterized in that: The following steps are involved: 1) Grind the fine-grained cassiterite oxide ore to a particle size of less than 37 microns with a mass percentage greater than 65%, add water in a mixing barrel, and stir to prepare a slurry with a slurry concentration of 30-35%; 2) adding copper sulfate, butyl xanthate and pine oil to the stirring barrel of step 1), removing sulfur by flotation to reduce the sulfur content to below 1%, and producing sulfur concentrate; 3) adding a desludging collector to the desulfurized slurry from step 2) and performing a flash flotation to remove some fine mud that is easy to float and poses a greater threat to flotation, and directly discarding the fine mud; 4) adding a dispersant to the slurry after desliming in step 3) and then entering a mixing tank; 5) adding a collector and an auxiliary collector to the stirring tank in step 4); 6) Floating the tin ore using a flotation machine to obtain a tin concentrate product. The regrinding in step 1) comprises a cyclone pre-classification and a primary grinding process. The cyclone overflow is required to have a particle size fraction of less than 37 microns greater than 65% by mass. The settled sand is returned to the tower mill for regrinding. The desludging collector in step 3) is a desludging collector TN-1 prepared by mixing 1-4 parts of sodium cetyl sulfate, 1-4 parts of polyoxyethylene stearate, 1-2 parts of sodium linoleate, and 1-2 parts of sodium petroleum sulfonate. The dispersant in step 4) is water glass, and the amount of water glass used is less than 400 g / t.

2. A flotation method for fine-grained cassiterite oxide ore according to claim 1, characterized in that: The collector in step 5) is sodium hydroxamate with mixed carbon chains.

3. The flotation method of fine-grained cassiterite oxide ore according to claim 1, characterized in that: The auxiliary collector in step 5) is an alcohol-ester mixture SN-F prepared by mixing diethyl carbonate and n-nonanol in a ratio of 2:3.

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