Beneficiation method for fine-grained andalusite ore

Abstract

The fine-grained andalusite ore beneficiation method comprises the following steps that under the rough grinding condition, a gangue mineral aggregate is formed by carbon-containing substances, quartz and mica, and the andalusite monomer dissociation degree is 80% or above; non-polar hydrocarbon oil is used as a collecting agent for reverse flotation, and a large number of gangue mineral aggregates such as carbonaceous, quartz and mica are removed; sulfuric acid is adopted as a pH regulator, a combination of oxalic acid and water glass is adopted as an inhibitor, a combination of sulfonate and hydroximic acid is adopted as a collecting agent, and andalusite flotation concentrate is obtained; and dry magnetic separation is conducted on the andalusite flotation concentrate, and iron and titanium impurity components are removed. A high-quality andalusite concentrate product with the Al2O3 grade being larger than 58% and the Fe2O3 content being smaller than 0.90% can be obtained from fine-grained andalusite ore with the andalusite content being 8-15 wt.% through the beneficiation method, the beneficiation index is excellent, and the beneficiation method has good application prospects and economic benefits.

Description

Technical Field

[0001] The present invention relates to the technical field of andalusite separation and purification, and particularly to a beneficiation method for fine-grained andalusite ore. Background Art

[0002] Andalusite is a typical aluminosilicate mineral and one of the kyanite group minerals. It has characteristics such as volume stability, low creep property, fire resistance, and thermal shock resistance, and is widely used as refractory materials, raw materials for aluminum-silicon alloys, coatings, and ceramic raw materials, etc. Since the content of andalusite minerals in andalusite ore is low and the impurity content is high, it cannot be directly applied and needs to be concentrated by beneficiation.

[0003] The beneficiation methods for andalusite vary greatly according to its particle size. For coarse-grained andalusite ore (particle size of andalusite above 1 mm), the "grinding - gravity separation for tailing rejection - magnetic separation" process is usually used for separation and purification; for fine-grained andalusite ore (particle size of andalusite below 1 mm), the "grinding - flotation - magnetic separation" process is usually used for separation. For example, the invention patent with the application date of August 30, 2018 and the application number of CN201811003197.9 discloses a pre-selection tailing rejection method for andalusite ore beneficiation. Different particle size products are obtained through the "crushing - roasting - dry grinding - classification" process flow, and the products with different particle sizes are respectively subjected to dry separation using a gas-solid two-phase fluidized bed with an external magnetic field to obtain andalusite rough concentrate. Using the above method, the content of andalusite minerals in the original ore can be increased from about 8% to about 17%, and the tailing rejection rate is more than 50%. The obtained rough concentrate product still needs further purification.

[0004] Regarding fine-grained andalusite ore, previous scholars have also conducted a large number of studies. For example, the invention patent with the application date of November 22, 2010 and the application number of CN201010553763.0 discloses a beneficiation method for andalusite ore. First, a grinding product with -0.074 mm accounting for 85% is obtained through grinding, and a spiral chute is used for desliming treatment. The product after desliming is subjected to reverse flotation for carbon removal - andalusite flotation, and the andalusite flotation concentrate is subjected to high-intensity magnetic separation to obtain andalusite concentrate. The grade of Al2O3 in the andalusite concentrate is 55% - 57%, and the content of Fe2O3 is 1.0% - 1.50%. This process flow is relatively complex, and high-quality concentrate products with Al2O3 grade greater than 58% and Fe2O3 content less than 0.9% cannot be obtained. Another example is the article titled "Experimental Study on Beneficiation of a Carbonaceous Difficult-to-Separate Andalusite Ore" published in the first issue of the journal "Mineral Resources Protection and Utilization" in 2013. For a certain carbonaceous difficult-to-separate andalusite ore, the "flotation for carbon removal - desliming - acid flotation - wet high-intensity magnetic separation" process flow is adopted. Under the grinding fineness of -0.074 mm accounting for 70%, andalusite concentrate with an Al2O3 content of 55.72% and an Fe2O3 content of 1.50% can be obtained. The Al2O3 content in the concentrate is relatively low, and the Fe2O3 content is too high.

[0005] Therefore, for fine-grained andalusite ore, innovating the beneficiation technology process to obtain high-quality andalusite concentrate is of great significance for the efficient development of low-grade fine-grained andalusite resources in China. Summary of the Invention

[0006] The present invention provides a beneficiation method for fine-grained andalusite ore. Under the condition of coarse grinding, by combining reverse flotation, andalusite flotation and dry magnetic separation, the efficient separation and purification of fine-grained andalusite ore can be realized, obtaining high-quality andalusite concentrate (Al2O3 content > 58 wt.%, Fe2O3 content < 0.9 wt.%). The separation indexes are excellent and it has good economic benefits.

[0007] The technical solution of the present invention is realized as follows: A beneficiation method for fine-grained andalusite ore, comprising the following steps:

[0008] (1) Grinding: After the original andalusite ore is ground, a grinding product with a particle size of -0.074 mm accounting for 30 wt.% - 50 wt.% is obtained; in the grinding product, the monomer dissociation degree of andalusite is more than 80%, and most of the main gangue minerals such as carbonaceous matter, quartz, mica, etc. still exist in the form of aggregates;

[0009] (2) Reverse flotation: Carry out reverse flotation on the grinding product, add non-polar hydrocarbon oil as the collector and pine oil as the frother, and a large amount of gangue minerals are removed by reverse flotation. The removal amount of reverse flotation impurities accounts for more than 60 wt.% of the grinding product, and a reverse flotation concentrate is obtained;

[0010] (3) Andalusite flotation: Carry out forward flotation of andalusite on the reverse flotation concentrate, use sulfuric acid as the pH adjuster, the combination of oxalic acid + water glass as the inhibitor, and the combination of sulfonate + hydroxamic acid as the collector to obtain andalusite flotation concentrate;

[0011] (4) Magnetic separation: Carry out dry magnetic separation on the andalusite flotation concentrate to further remove impurity components such as iron and titanium, and obtain andalusite concentrate. The Al2O3 content in the andalusite concentrate is greater than 58 wt.%, and the Fe2O3 content is less than 0.90 wt.%.

[0012] Furthermore, in step (2), the reverse flotation includes one roughing to obtain reverse flotation impurities 1 and reverse flotation rough concentrate. The reverse flotation rough concentrate is subjected to one scavenging to obtain reverse flotation impurities 2 and reverse flotation concentrate. Reverse flotation impurities 1 and reverse flotation impurities 2 are combined to obtain reverse flotation impurities, and the reverse flotation concentrate is used as the feed for andalusite flotation.

[0013] Furthermore, in step (3), the andalusite flotation includes two roughings. The two roughing concentrates are combined to obtain the total roughing concentrate, and the roughing tailings are the flotation tailings. The total roughing concentrate is subjected to 3 - 4 cleanings to obtain andalusite flotation concentrate and cleaning middlings, and the cleaning middlings are sequentially returned to the main process.

[0014] Further, in step (4), the magnetic separation includes one rough separation to obtain magnetic substances 1 and non-magnetic substances. The non-magnetic substances are subjected to one fine separation to obtain magnetic substances 2 and andalusite concentrate. Magnetic substances 1 and magnetic substances 2 are combined to obtain magnetic substances.

[0015] Further, in step (2), the non-polar hydrocarbon oil is any one of kerosene, diesel oil, and transformer oil. The total dosage of rough separation + scavenging is 100 g / t - 500 g / t, and the total dosage of pine oil as the frother for rough separation + scavenging is 50 g / t - 150 g / t.

[0016] Further, in step (3), the sulfonate is any one of sodium petroleum sulfonate and sodium dodecyl sulfonate, and the hydroxamic acid is any one of salicylhydroxamic acid and benzohydroxamic acid. The mass ratio of the sulfonate to the hydroxamic acid is 2:1.

[0017] Further, in step (3), in the rough separation operation, the total dosage of sulfuric acid is 1000 g / t - 3000 g / t, the pH value of the pulp is 3.5 - 4.5, the total dosage of oxalic acid is 200 g / t - 1000 g / t, the total dosage of water glass is 500 g / t - 1500 g / t, the total dosage of sulfonate is 300 g / t - 3000 g / t, and the total dosage of hydroxamic acid is 150 g / t - 1500 g / t.

[0018] Further, in step (3), in the fine separation operation, the total dosage of sulfuric acid is 1000 g / t - 3000 g / t, the pH value of the pulp is 3.5 - 4.5, the total dosage of oxalic acid is 300 g / t - 1500 g / t, the total dosage of water glass is 300 g / t - 1500 g / t, the total dosage of sulfonate is 200 g / t - 1500 g / t, and the total dosage of hydroxamic acid is 100 g / t - 750 g / t.

[0019] Further, in step (4), the magnetic separation equipment is a dry drum magnetic separator, the magnetic field strength is 358.2 kA / m - 716.5 kA / m, and the drum rotation speed is 40 r / min - 50 r / min.

[0020] Further, in step (1), the andalusite content in the andalusite raw ore is 8 wt.% - 15 wt.%, the quartz content is 20 wt.% - 40 wt.%, the mica content is 10 wt.% - 30 wt.%, and the carbonaceous (carbon-containing substances) content is 1 wt.% - 10 wt.%.

[0021] The beneficial effects of the present invention:

[0022] In order to improve the dissociation degree of andalusite monomers, facilitate the improvement of the grade of subsequent concentrates, and reduce the impurity content, in the prior art, the raw ore is mostly finely ground, such as -0.074mm accounting for more than 70%-80%, resulting in the main gangue minerals such as carbonaceous matter, quartz, and mica existing mostly in the form of monomers. In the present invention, at a relatively coarse grinding fineness (-0.074mm accounting for 30wt.%-50wt.%), the dissociation degree of andalusite monomers is more than 80%, and most of the main gangue minerals such as carbonaceous matter, quartz, and mica still exist in the form of aggregates. Then, by means of the strong collecting ability of non-polar hydrocarbon oils such as kerosene for carbonaceous matter, a large amount of "carbonaceous matter - quartz - mica" gangue mineral aggregates are removed by reverse flotation (the removal amount is more than 60wt.%), and the subsequent andalusite flotation environment is optimized as much as possible.

[0023] For the flotation of andalusite in the present invention, under acidic conditions, oxalic acid + water glass combination is used as the inhibitor, and sulfonate + hydroxamic acid combination is used as the collector. The use of the sulfonate + hydroxamic acid combination overcomes the problem of poor selectivity of conventional collectors for silicate gangue minerals such as andalusite and quartz during flotation, obtaining andalusite flotation concentrate. Then, a dry rolling magnetic separator suitable for coarser-grained materials is used for medium-intensity magnetic separation to remove impurities. The use of dry magnetic separation equipment overcomes the problems of low separation accuracy and serious inclusion during the separation of minerals with small magnetic differences by wet magnetic separators, and finally obtains a high-quality andalusite concentrate product.

[0024] The present invention uses the above technical method to process low-grade fine-grained andalusite ore with an andalusite content of 8wt.%-15wt.% in the raw ore. The Al2O3 grade of the obtained andalusite concentrate is increased from 55%-57% by the conventional method to more than 58%, and the Fe2O3 content is decreased from 1.0%-1.5% to less than 0.9%. The product grade can be increased from HZ-55 in the black metallurgy industry standard YBT4032-2010 "Kyanite, Andalusite, Sillimanite" to above HZ-56.

[0025] In addition, the method of the present invention reduces the grinding cost (the grinding fineness is reduced from more than 80wt.% of -0.074mm by the conventional method to 30wt.%-50wt.% of -0.074mm), and the product grade is increased from HZ-55 to above HZ-56. With the increase in grade, the price of the concentrate will also increase, which is conducive to greatly improving economic benefits. Estimated by the scale of a concentrator with an annual output of 20,000 tons of andalusite concentrate, the economic benefits can be increased by more than 12 million yuan. Description of the Drawings

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0027] Figure 1 This is the process flow diagram of the beneficiation method for fine-grained andalusite ore of the present invention. Detailed implementation manners

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0029] Embodiment 1

[0030] The andalusite ore sample processed in this embodiment is collected from a certain place in Liaoning. The original ore andalusite content is about 12wt.%. The main gangue minerals are quartz 32.55wt.%, biotite 22.62wt.%, carbonaceous 3.50wt.%, etc. The beneficiation method of this embodiment is carried out according to the Figure 1 shown process, including the following steps:

[0031] 1) Use a rod mill to grind the -2mm raw ore. The grinding concentration is 60%, the grinding fineness is about 42wt.% of -0.074mm, and the monomer dissociation degree of andalusite is about 85%;

[0032] 2) Transfer the grinding product to an XFD type flotation cell, and adjust the pulp concentration to about 35wt.% to obtain a pulp product;

[0033] 3) Conduct reverse flotation roughing on the grinding product. The dosage of kerosene for roughing is 200g / t, and the dosage of pine oil is 50g / t. After stirring for 3 minutes each, start the reverse flotation roughing. The roughing time is 3 minutes to obtain reverse flotation impurities 1 and reverse flotation rough concentrate. Conduct scavenging on the reverse flotation rough concentrate. The dosage of kerosene for scavenging is 100g / t, and the dosage of pine oil is 25g / t. After stirring for 3 minutes each, start the reverse flotation scavenging. The scavenging time is 2 minutes to obtain reverse flotation impurities 2 and reverse flotation concentrate. Reverse flotation impurities 1 and reverse flotation impurities 2 are combined to obtain reverse flotation impurities.

[0034] 4) For the anionic flotation concentrate, perform andalusite flotation. Sequentially add 1500 g / t of sulfuric acid as the pH adjuster (the pulp pH value is about 3.8), 400 g / t + 400 g / t of the combined inhibitors oxalic acid + water glass, and 1000 g / t + 500 g / t of the combined collectors sodium petroleum sulfonate + salicylhydroxamic acid. After stirring for 3 minutes each, start the first rough flotation of andalusite. The time for the first rough flotation of andalusite is 2.5 minutes to obtain the first rough flotation concentrate of andalusite and the first rough flotation tailings. For the first rough flotation tailings of andalusite, sequentially add 500 g / t of sulfuric acid as the pH adjuster (the pulp pH value is about 4.0), 200 g / t + 200 g / t of the combined inhibitors oxalic acid + water glass, and 500 g / t + 250 g / t of the combined collectors sodium petroleum sulfonate + salicylhydroxamic acid. After stirring for 3 minutes each, start the second rough flotation of andalusite. The flotation time for the second rough flotation is 1 minute to obtain the second rough flotation concentrate of andalusite and the flotation tailings. The first and second rough flotation concentrates of andalusite are combined to obtain the total rough flotation concentrate.

[0035] 5) Perform 4 times of cleaning on the total rough flotation concentrate of andalusite. For the first cleaning, add 500 g / t of sulfuric acid, 150 g / t + 150 g / t of the combined inhibitors oxalic acid + water glass. After stirring for 3 minutes each, start flotation. The cleaning time is 2 minutes. For the second cleaning, add 300 g / t of sulfuric acid, 100 g / t + 100 g / t of the combined inhibitors oxalic acid + water glass, and 100 g / t + 50 g / t of the combined collectors sodium petroleum sulfonate + salicylhydroxamic acid. After stirring for 3 minutes each, start flotation. The cleaning time is 1.5 minutes. For the third cleaning, add 250 g / t of sulfuric acid, 100 g / t + 100 g / t of the combined inhibitors oxalic acid + water glass. After stirring for 3 minutes each, start flotation. The cleaning time is 1.5 minutes. For the fourth cleaning, add 250 g / t of sulfuric acid, 100 g / t + 100 g / t of the combined inhibitors oxalic acid + water glass, and 100 g / t + 50 g / t of the combined collectors sodium petroleum sulfonate + salicylhydroxamic acid. After stirring for 3 minutes each, start flotation. The cleaning time is 1.5 minutes. The first cleaning middlings are returned to the first rough flotation of andalusite, the second cleaning middlings are returned to the first cleaning, the third cleaning middlings are returned to the second cleaning, and the fourth cleaning middlings are returned to the third cleaning. After 4 times of cleaning, the andalusite rough concentrate obtains the andalusite flotation concentrate.

[0036] 6) Perform 2 times of dry magnetic separation on the andalusite flotation concentrate. The magnetic field intensity for the rough separation is 477.7 kA / m, and the drum speed is 45 r / min to obtain magnetic substances 1 and non-magnetic substances. For the non-magnetic substances, perform cleaning. The magnetic field intensity for the cleaning is 676.8 kA / m, and the drum speed is 45 r / min to obtain magnetic substances 2 and the andalusite concentrate. Magnetic substances 1 and magnetic substances 2 are combined into the total magnetic substances.

[0037] Table 1 Separation effect of Example 1 / %

[0038]

[0039] As can be seen from Table 1, by adopting the technical process of the present invention, a certain kyanite ore in Liaoning with a kyanite mineral content of 12.10 wt.% can obtain high-quality kyanite concentrate with an Al2O3 grade of 58.35% and an Fe2O3 content of 0.84% after sorting and purification.

[0040] Example 2

[0041] This example is basically the same as Example 1, the differences are as follows: The kyanite ore sample is collected from a certain place, the original ore kyanite content is about 8.5 wt.%, and the main gangue minerals are quartz 41.21 wt.%, biotite 14.17 wt.%, carbonaceous 1.80 wt.%, etc.; the grinding fineness is about 45 wt.% of -0.074 mm, and the monomer dissociation degree of kyanite is about 83%; the collector combination used for rough selection and cleaning of kyanite is sodium petroleum sulfonate + benzohydroxamic acid, and the dosage remains unchanged; other test conditions and reagent dosages are the same as those in Example 1.

[0042] Table 2 Separation effect of Example 2 / %

[0043]

[0044] As can be seen from Table 2, by adopting the technical process of the present invention, a certain fine-grained kyanite ore with a kyanite mineral content of 8.48 wt.% can obtain high-quality kyanite concentrate with an Al2O3 grade of 58.07% and an Fe2O3 content of 0.89% after sorting and purification.

[0045] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for beneficiating fine-grained andalusite ore, characterized in that: The following steps are involved: (1) Grinding: After the andalusite ore is ground, a grinding product with a particle size of -0.074 mm accounting for 30wt.%-50wt.% is obtained; (2) Reverse flotation: The ground product is subjected to reverse flotation, non-polar hydrocarbon oil is added as a collector, and pine oil is used as a frother. The amount of impurities removed by reverse flotation accounts for more than 60 wt.% of the ground product, and a reverse flotation concentrate is obtained; (3) Andalusite flotation: The reverse flotation concentrate is subjected to andalusite positive flotation, with sulfuric acid as a pH adjuster, oxalic acid + water glass combination as an inhibitor, and sulfonate + hydroxamic acid combination as a collector to obtain andalusite flotation concentrate; (4) Magnetic separation: The andalusite flotation concentrate is subjected to dry magnetic separation to remove iron and titanium impurities to obtain andalusite concentrate. The Al2O3 content in the andalusite concentrate is greater than 58wt.%, and the Fe2O3 content is less than 0.90wt.%.

2. A method for beneficiating fine-grained andalusite ore according to claim 1, characterized in that: In step (2), the reverse flotation includes a roughing process to obtain reverse flotation impurities 1 and reverse flotation rough concentrate, the reverse flotation rough concentrate is subjected to a scavenging process to obtain reverse flotation impurities 2 and reverse flotation concentrate, the reverse flotation impurities 1 and the reverse flotation impurities 2 are combined to obtain reverse flotation impurities, and the reverse flotation concentrate is used as the flotation feedstock for andalusite.

3. A method for beneficiating fine-grained andalusite ore according to claim 1, characterized in that: In step (3), the andalusite flotation includes two roughing operations. The two roughing concentrates are combined to obtain a roughing total concentrate. The roughing tailings are flotation tailings. The roughing total concentrate is subjected to 3-4 rounds of concentrating to obtain andalusite flotation concentrate and concentrating middlings. The concentrating middlings are returned to the main process in sequence.

4. A method for beneficiating fine-grained andalusite ore according to claim 1, characterized in that: In step (4), the magnetic separation includes a roughing process to obtain magnetic material 1 and non-magnetic material. The non-magnetic material is finely concentrated to obtain magnetic material 2 and andalusite concentrate. The magnetic material 1 and the magnetic material 2 are combined to obtain the magnetic material.

5. A method for beneficiating fine-grained andalusite ore according to claim 2, characterized in that: In step (2), the non-polar hydrocarbon oil is any one of kerosene, diesel and transformer oil, the total amount of roughing + scavenging is 100g / t-500g / t, and the total amount of roughing + scavenging foaming agent pine oil is 50g / t-150g / t.

6. A method for beneficiating fine-grained andalusite ore according to claim 1, characterized in that: In step (3), the sulfonate is any one of sodium petroleum sulfonate and sodium dodecyl sulfonate, the hydroxamic acid is any one of salicylic hydroxamic acid and benzohydroxamic acid, and the mass ratio of the sulfonate to the hydroxamic acid is 2:

1.

7. A method for beneficiating fine-grained andalusite ore according to claim 3, characterized in that: In step (3), the total amount of sulfuric acid used in the roughing operation is 1000g / t-3000g / t, the pulp pH value is 3.5-4.5, the total amount of oxalic acid used is 200g / t-1000g / t, the total amount of water glass used is 500g / t-1500g / t, the total amount of sulfonate used is 300g / t-3000g / t, and the total amount of hydroxamic acid used is 150g / t-1500g / t.

8. A method for beneficiating fine-grained andalusite ore according to claim 3, characterized in that: In step (3), the total amount of sulfuric acid used in the concentrating operation is 1000g / t-3000g / t, the pH value of the slurry is 3.5-4.5, the total amount of oxalic acid used is 300g / t-1500g / t, the total amount of water glass used is 300g / t-1500g / t, the total amount of sulfonate used is 200g / t-1500g / t, and the total amount of hydroxamic acid used is 100g / t-750g / t.

9. A method for beneficiating fine-grained andalusite ore according to claim 1, characterized in that: In step (4), the magnetic separation equipment is a dry drum magnetic separator, the magnetic field strength is 358.2kA / m-716.5kA / m, and the drum speed is 40r / min-50r / min.

10. A method for beneficiating fine-grained andalusite ore according to claim 1, characterized in that: In step (1), the andalusite content of the andalusite ore is 8wt.%-15wt.%.

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