Dolomite-removing combined collector for reverse flotation of phosphate rock and its application method

Abstract

The present invention provides a magnesium-removing combined collector for reverse flotation of phosphate rock and an application method thereof. The active components of the magnesium-removing combined collector include cetyltrimethylammonium bromide, octadecyldimethyl tertiary amine and linolenic acid. By combining an anionic collector and a cationic collector, the surface activity of cetyltrimethylammonium bromide and octadecyldimethyl tertiary amine can be used to improve the water solubility and dispersibility of linolenic acid, strengthen the collecting ability for gangue minerals, and at the same time reduce the adsorption of linolenic acid on apatite, thereby reducing the loss rate of P2O5 in the flotation process. The magnesium-removing combined collector for reverse flotation of phosphate rock prepared by the present invention greatly reduces the reagent unit consumption, weakens the sensitivity of the collector to impurity ions in the pulp, and reduces the loss rate of P2O5 in the flotation process compared with the single gangue mineral collectors oleic acid and fatty acid.

Description

Technical Field

[0001] The present invention relates to the technical field of flotation separation, and particularly relates to a magnesium-removing combined collector for reverse flotation of phosphate rock and an application method thereof. Background Art

[0002] Phosphate rock is an important chemical mineral raw material. China is rich in phosphate rock resources, but there are many lean ores and few rich ores. Most of them are medium and low-grade silica-calcium phosphate ores, namely collophanite. Collophanite contains a large amount of impurities, and calcium, magnesium, silicon, etc. are closely associated with phosphate minerals, making separation difficult. In particular, the magnesium-containing mineral dolomite has extremely similar floatability to collophanite and is even more difficult to separate. If the magnesium content in phosphate concentrate is too high, it will seriously affect the quality of downstream products. For example, when producing phosphoric acid ammonium, insoluble MgNH 2+ PO 4 PO 4 precipitates will form, thus affecting the product quality. When producing phosphoric acid, it will affect the purity of phosphoric acid, etc. In the practical exploration in recent decades, the most studied method is to inhibit phosphate minerals under acidic conditions and use anionic collectors such as oleic acid and fatty acids for reverse flotation to separate dolomite.

[0003] In the prior art, in the patent document with the application number 201310293908.1, the publication date of October 23, 2013, and the title of "A Collector for Reverse Flotation of Collophanite and Its Preparation Method", a collector for reverse flotation of collophanite is obtained by compounding modified fatty acid, strong alkali solution and fatty acid. Although this collector has a certain collecting effect on dolomite, its selectivity is poor, the loss rate of P 2 O 5 is relatively high, and it is sensitive to impurity ions in the pulp.

[0004] In view of this, it is necessary to design an improved magnesium-removing combined collector for reverse flotation of phosphate rock and an application method thereof to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a magnesium-removing combined collector for reverse flotation of phosphate rock and an application method thereof.

[0006] To achieve the above invention purpose, the present invention provides a magnesium-removing combined collector for reverse flotation of phosphate rock. The active components of the magnesium-removing combined collector include cetyltrimethylammonium bromide, octadecyldimethyl tertiary amine and linolenic acid, and the mass ratio of the three added is (2-3):(1-2):(5-7).

[0007] Preferably, the aqueous solution of cetyltrimethylammonium bromide is composed of the following raw materials by mass: 1 part of cetyltrimethylammonium bromide, 0.1 part of acetic acid, and 10 parts of water; the aqueous solution of octadecyldimethylamine is composed of the following raw materials by mass: 1 part of octadecyldimethylamine, 0.2 part of acetic acid, and 10 parts of water; the linolenic acid is in the form of a stock solution.

[0008] Furthermore, the present invention also provides an application method of the magnesium-removing combined collector for reverse flotation of phosphate rock in the flotation separation of phosphate rock, which includes the following steps:

[0009] S1. Crush and grind the as-mined phosphate rock ore to obtain the minerals to be floated, and add water to obtain the raw ore pulp.

[0010] S2. Put the raw ore pulp obtained in step S1 into a flotation machine for flotation separation. This flotation includes one rough selection, one fine selection, and one scavenging to obtain phosphate concentrate and gangue minerals.

[0011] Preferably, in step S2, during the rough selection process, a mixed acid and the magnesium-removing collector are added. The addition amount of the mixed acid is 10 - 15 kg / t, and the dosage of the magnesium-removing collector is 1 - 1.5 kg / t.

[0012] Preferably, the mixed acid is prepared from sulfuric acid and phosphoric acid.

[0013] Preferably, the mass ratio of the sulfuric acid to the phosphoric acid is 2:1.

[0014] Preferably, in step S2, during the scavenging process, the mixed acid is added. The dosage of the mixed acid is 3 - 5 kg / t.

[0015] Preferably, in step S2, during the fine selection process, the mixed acid and the magnesium-removing collector are added. The dosage of the mixed acid is 5 - 8 kg / t, and the dosage of the magnesium-removing collector is 0.4 - 0.8 kg / t.

[0016] Preferably, in step S1, the fineness of the minerals to be floated with a particle size of -0.074 mm accounts for 80 - 90%.

[0017] Preferably, in step S1, the mass percentage of the raw ore pulp is 28 - 35%.

[0018] The beneficial effects of the present invention are:

[0019] The magnesium-removing combined collector for reverse flotation of phosphate rock provided by the present invention has active components including cetyltrimethylammonium bromide, octadecyldimethyl tertiary amine, and linolenic acid. By combining an anionic collector and a cationic collector, the above magnesium-removing combined collector can utilize the surface activity of cetyltrimethylammonium bromide and octadecyldimethyl tertiary amine to improve the water solubility and dispersibility of linolenic acid, thereby enhancing the complexing ability and selectivity of linolenic acid for Mg 2+ , strengthening the collecting ability for gangue minerals, and improving the flotation separation effect of removing gangue minerals from the pulp. At the same time, the presence of cetyltrimethylammonium bromide and octadecyldimethyl tertiary amine can also reduce the adsorption of linolenic acid on apatite, reducing the loss rate of P 2 O 5 during the flotation process. The magnesium-removing combined collector for reverse flotation of phosphate rock prepared by the present invention, compared with the single gangue mineral collectors oleic acid and fatty acid, greatly reduces the unit consumption of the reagent, weakens the sensitivity of the collector to impurity ions in the pulp, and reduces the loss rate of P 2 O 5 . BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 FIG. is a schematic process flow diagram of the magnesium-removing combined collector for reverse flotation of phosphate rock proposed by the present invention used for reverse flotation of phosphate rock. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in detail below with reference to the drawings and specific embodiments.

[0022] Here, it should also be noted that in order to avoid obscuring the present invention due to unnecessary details, only the structures and / or processing steps closely related to the solution of the present invention are shown in the drawings, while other details less related to the present invention are omitted.

[0023] In addition, it should also be noted that the term "comprises", "comprising", or any other variation thereof is intended to cover a non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or device.

[0024] The present invention provides a magnesium-removing combined collector for reverse flotation of phosphate rock, and its active components include cetyltrimethylammonium bromide, octadecyldimethyl tertiary amine and linolenic acid, and the mass ratio of the three added is (2-3):(1-2):(5-7); wherein, the aqueous solution of cetyltrimethylammonium bromide is in the following mass fractions of each raw material: 1 part of cetyltrimethylammonium bromide, 0.1 part of acetic acid, and 10 parts of water; the aqueous solution of octadecyldimethyl tertiary amine is in the following mass fractions of each raw material: 1 part of octadecyldimethyl tertiary amine, 0.2 part of acetic acid, and 10 parts of water; linolenic acid is in the form of a stock solution.

[0025] Specifically, please refer to Figure 1 As shown, the present invention also provides a specific method for using the magnesium-removing combined collector for reverse flotation of phosphate rock for magnesium removal from collophanite, including the following steps:

[0026] S1. The taken phosphate rock raw ore is crushed and then ground finely to obtain flotation minerals with a grinding fineness of -0.074 mm accounting for 80-90%, and after adding water, a raw ore pulp with a mass percentage of 28-35% is obtained;

[0027] S2. The raw ore pulp obtained in step S1 is put into a flotation machine for flotation separation. This flotation includes one rough selection, one fine selection and one scavenging, to obtain phosphate concentrate and gangue minerals.

[0028] Rough selection process: The raw ore pulp is put into a flotation machine for flotation to obtain tailings and foam distributed on the underflow;

[0029] Fine selection process: The tailings obtained in the rough selection process are subjected to fine selection. The fine selection foam is returned to the previous operation and returned to the rough selection process for rough selection to form a closed circuit, and phosphate concentrate is obtained;

[0030] Scavenging process: The foam obtained in the rough selection process is scraped out for scavenging. The foam and gangue minerals are obtained in the scavenging process. The foam is scraped out and returned to the rough selection process for rough selection to form a closed circuit.

[0031] Preferably, in step S2, a mixed acid and a magnesium-removing collector are added in the rough selection process. The addition amount of the mixed acid is 10-15 kg / t, and the dosage of the magnesium-removing collector is 1-1.5 kg / t; wherein, the mixed acid is prepared from sulfuric acid and phosphoric acid, and the mass ratio of sulfuric acid to phosphoric acid is 2:1.

[0032] Preferably, in step S2, a mixed acid is added in the scavenging process, and the dosage of the mixed acid in the scavenging process is 3-5 kg / t.

[0033] Preferably, in step S2, a mixed acid and a magnesium-removing collector are added in the fine selection process. The dosage of the mixed acid is 5-8 kg / t, and the dosage of the magnesium-removing collector is 0.4-0.8 kg / t.

[0034] The following further describes the magnesium - removing combined collector for reverse flotation of phosphate rock according to the present invention with specific embodiments:

[0035] Example 1

[0036] In this example, a high - magnesium phosphate rock from Yunnan is used as the object. The raw ore contains P 2 O 5 21.68% and MgO 6.13%. The main ore minerals are apatite, and the main gangue minerals are dolomite, quartz, etc.

[0037] The active components of the magnesium - removing combined collector used in this example include cetyltrimethylammonium bromide, octadecyldimethylamine, and linolenic acid. The mass ratio of the three added is 2:1:7. Among them, the aqueous solution of cetyltrimethylammonium bromide is prepared according to the mass fraction of each raw material: 1 part of cetyltrimethylammonium bromide, 0.1 part of acetic acid, and 10 parts of water; the aqueous solution of octadecyldimethylamine is prepared according to the mass fraction of each raw material: 1 part of octadecyldimethylamine, 0.2 part of acetic acid, and 10 parts of water; linolenic acid is in the form of a stock solution.

[0038] Applying the magnesium - removing combined collector for reverse flotation of phosphate rock proposed by the present invention to conduct flotation separation on the above - mentioned high - magnesium phosphate rock includes the following steps:

[0039] S1. The high - magnesium phosphate rock is crushed to - 2 mm and then ground finely to obtain a flotation - ready mineral with a grinding fineness of 87.5% passing through - 0.074 mm. After adding water, a raw ore pulp with a mass percentage of 30% is obtained.

[0040] S2. The raw ore pulp obtained in step S1 is put into a flotation machine for flotation separation. This flotation includes one roughing, one cleaning, and one scavenging to obtain phosphorus concentrate and gangue minerals.

[0041] Roughing process: The raw ore pulp is put into the flotation machine for flotation to obtain tailings and foam distributed on the underflow. Among them, in this process, a mixed acid and a magnesium - removing combined collector are added. The dosage of the mixed acid is 12 kg / t, and the dosage of the magnesium - removing combined collector is 1.3 kg / t. The mixed acid is obtained by mixing 8 kg / t of sulfuric acid and 4 kg / t of phosphoric acid.

[0042] Cleaning process: The tailings obtained in the roughing process are subjected to cleaning. The cleaning foam is returned to the previous operation, that is, returned to the roughing process for roughing to form a closed - circuit cycle to obtain phosphorus concentrate. Among them, in this process, a mixed acid and a magnesium - removing combined collector are added. The dosage of the mixed acid is 6 kg / t, and the dosage of the magnesium - removing combined collector is 0.5 kg / t. The mixed acid is obtained by mixing 4 kg / t of sulfuric acid and 2 kg / t of phosphoric acid.

[0043] Scavenging process: The foam obtained from the roughing process is scraped out for scavenging. The scavenging process yields foam and gangue minerals. The foam is scraped out and returned to the roughing process for roughing, forming a closed circuit. Among them, the dosage of the mixed acid in this process is 3 kg / t, and the mixed acid is obtained by mixing 2 kg / t of sulfuric acid and 1 kg / t of phosphoric acid.

[0044] Comparative Example 1

[0045] The difference between this comparative example and Example 1 is only that: in the combined magnesium-removing collector used, the mass ratio of cetyltrimethylammonium bromide, octadecyldimethyl tertiary amine, and linolenic acid is 1:1:7. The above combined magnesium-removing collector is used for flotation separation of high-magnesium phosphate ore. The steps of flotation separation are basically the same as those in Example 1 and will not be elaborated here.

[0046] Comparative Example 2

[0047] The difference between this comparative example and Example 1 is only that: in the combined magnesium-removing collector used, the mass ratio of cetyltrimethylammonium bromide, octadecyldimethyl tertiary amine, and linolenic acid is 2:0:7. The above combined magnesium-removing collector is used for flotation separation of high-magnesium phosphate ore. The steps of flotation separation are basically the same as those in Example 1 and will not be elaborated here.

[0048] Comparative Example 3

[0049] The difference between this comparative example and Example 1 is only that: in the combined magnesium-removing collector used, the mass ratio of cetyltrimethylammonium bromide, octadecyldimethyl tertiary amine, and linolenic acid is 2:1:4. The above combined magnesium-removing collector is used for flotation separation of high-magnesium phosphate ore. The steps of flotation separation are basically the same as those in Example 1 and will not be elaborated here.

[0050] Comparative Example 4

[0051] The difference between this comparative example and Example 1 is only that: fatty acid is used as the combined magnesium-removing collector. The above combined magnesium-removing collector is used for flotation separation of high-magnesium phosphate ore. The steps of flotation separation are basically the same as those in Example 1 and will not be elaborated here. The flotation separation results when different combined magnesium-removing collectors are used in Example 1 and Comparative Examples 1 to 4 are shown in Table 1. It can be seen from the table that when the mass ratio of cetyltrimethylammonium bromide, octadecyldimethyl tertiary amine, and linolenic acid added in the combined magnesium-removing collector is within the range of (2 - 3):(1 - 2):(5 - 7), the synergistic effect between the three can be utilized to effectively separate P 2 O 5 from the ore by flotation.

[0052] Table 1 Flotation separation results when different combined magnesium-removing collectors are used in Example 1 and Comparative Examples 1 to 4

[0053]

[0054] In summary, the magnesium-removing combined collector for reverse flotation of phosphate rock provided by the present invention, the active components of the magnesium-removing combined collector include cetyltrimethylammonium bromide, octadecyldimethyl tertiary amine and linolenic acid; by combining an anionic collector and a cationic collector, the surface activity of cetyltrimethylammonium bromide and octadecyldimethyl tertiary amine can be used to improve the water solubility and dispersibility of linolenic acid, strengthen the collecting ability for gangue minerals, and effectively remove gangue minerals in the pulp; at the same time, the presence of cetyltrimethylammonium bromide and octadecyldimethyl tertiary amine can also reduce the adsorption of linolenic acid on apatite, reducing the loss rate of P 2 O 5 during the flotation process.

[0055] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A magnesium-removing combined collector for reverse flotation of phosphate rock, characterized in that, the active components of the magnesium-removing combined collector include cetyltrimethylammonium bromide, octadecyldimethylamine and linolenic acid, and the mass ratio of the three added is 2:1:7; wherein, the aqueous solution of cetyltrimethylammonium bromide is in the following mass fractions of each raw material: 1 part of cetyltrimethylammonium bromide, 0.1 part of acetic acid, and 10 parts of water; the aqueous solution of octadecyldimethylamine is in the following mass fractions of each raw material: 1 part of octadecyldimethylamine, 0.2 part of acetic acid, and 10 parts of water; the linolenic acid is in the original solution.

2. The application method of the magnesium-removing combined collector for reverse flotation of phosphate rock according to claim 1 in the flotation separation of phosphate rock, characterized in that, it includes the following steps: S1. Crush and grind the taken phosphate rock raw ore to obtain the minerals to be floated, and add water to obtain the raw ore pulp; S2. Put the raw ore pulp obtained in step S1 into a flotation machine for flotation separation. This flotation includes one rough selection, one fine selection and one scavenging to obtain phosphate concentrate and gangue minerals.

3. The application method of the magnesium-removing combined collector for reverse flotation of phosphate rock according to claim 2 in the flotation separation of phosphate rock, characterized in that, in step S2, a mixed acid and the magnesium-removing combined collector are added during the rough selection process. The addition amount of the mixed acid is 10-15 kg / t, and the dosage of the magnesium-removing combined collector is 1-1.5 kg / t.

4. The application method of the magnesium-removing combined collector for reverse flotation of phosphate rock according to claim 3 in the flotation separation of phosphate rock, characterized in that, the mixed acid is prepared from sulfuric acid and phosphoric acid.

5. The application method of the magnesium-removing combined collector for reverse flotation of phosphate rock according to claim 4 in the flotation separation of phosphate rock, characterized in that, the mass ratio of the sulfuric acid to the phosphoric acid is 2:

1.

6. The application method of the magnesium-removing combined collector for reverse flotation of phosphate rock according to claim 3 in the flotation separation of phosphate rock, characterized in that, in step S2, the mixed acid is added during the scavenging process. The dosage of the mixed acid is 3-5 kg / t.

7. The application method of the magnesium-removing combined collector for reverse flotation of phosphate rock according to claim 3 in the flotation separation of phosphate rock, characterized in that, in step S2, the mixed acid and the magnesium-removing combined collector are added during the fine selection process. The dosage of the mixed acid is 5-8 kg / t, and the dosage of the magnesium-removing combined collector is 0.4-0.8 kg / t.

8. The application method of the magnesium-removing combined collector for reverse flotation of phosphate rock according to claim 2 in the flotation separation of phosphate rock, characterized in that, in step S1, the fineness of the minerals to be floated with -0.074 mm accounts for 80-90%.

9. The application method of the magnesium-removing combined collector for reverse flotation of phosphate rock according to claim 2 in the flotation separation of phosphate rock, characterized in that, in step S1, the mass percentage of the raw ore pulp is 28-35%.

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