CN115957894A - Phosphogypsum whitening and purifying process - Google Patents

Phosphogypsum whitening and purifying process Download PDF

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Publication number
CN115957894A
CN115957894A CN202211301509.0A CN202211301509A CN115957894A CN 115957894 A CN115957894 A CN 115957894A CN 202211301509 A CN202211301509 A CN 202211301509A CN 115957894 A CN115957894 A CN 115957894A
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flotation
phosphogypsum
percent
reverse
reagent
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李会勇
李景超
曹亦俊
范桂侠
彭伟军
周国莉
汤建伟
解田
徐春
何光亮
刘松林
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Jiangsu Zhongfu Mining Technology Co ltd
Zhengzhou University
Wengfu Group Co Ltd
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Jiangsu Zhongfu Mining Technology Co ltd
Zhengzhou University
Wengfu Group Co Ltd
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    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02WCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00Technologies for solid waste management
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    • Y02W30/91Use of waste materials as fillers for mortars or concrete

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Abstract

The invention relates to a whitening and purifying process based on phosphogypsum, belongs to the field of phosphorus chemical industry solid waste treatment, and solves the problem that the existing phosphogypsum whitening and purifying process is not thorough in impurity removal and purification. A whitening and purifying process of phosphogypsum, which comprises the following steps: connecting four cyclone-static microbubble flotation columns in series; carrying out reverse flotation twice; carrying out two times of direct flotation; and pumping the phosphogypsum concentrate obtained after twice reverse flotation and twice forward flotation into plate-and-frame filter pressing equipment for dehydration, and drying after the dehydration is finished to obtain the whitened and purified phosphogypsum. In the invention, a cyclone-static microbubble flotation column is used as a flotation device, a flotation process combining 'two-reverse two-positive' flotation is adopted, and under the conditions that the whiteness of the phosphogypsum raw ore is 35% (drying at 45 ℃) and the grade (calculated by CaSO4.2H2O) is 90%, the whiteness of the phosphogypsum concentrate can be improved to 74.5% (drying at 45 ℃) by flotation, and the grade (calculated by CaSO4.2H2O) is improved to 98.2% by flotation.

Description

Phosphogypsum whitening and purifying process
Technical Field
The invention relates to the field of treatment of solid waste of phosphorus chemical industry, in particular to a whitening and purifying process of phosphogypsum.
Background
Phosphogypsum is a byproduct in the production process of wet-process phosphoric acid, and 4.5-5 tons of phosphogypsum are produced per ton of phosphoric acid. With the rapid development of phosphate fertilizer and phosphorus chemical industry in China, the emission of phosphogypsum as a byproduct is nearly 7500 million tons every year. In China, the utilization rate of the phosphogypsum at the present stage is only about 40 percent, so that a large amount of stockpiles are caused, a large amount of land resources are occupied, the environment pollution is caused, the investment and operation cost of a slag yard are high, and a large burden is caused to phosphatic fertilizer and phosphorus chemical enterprises. The problems of purification treatment and resource utilization of the phosphogypsum become the key point for healthy and sustainable development of the phosphorus fertilizer and the phosphorus chemical industry.
The utilization of the phosphogypsum is based on the premise that the phosphogypsum is upgraded and purified, and contains a plurality of harmful impurities such as phosphorus, fluorine, organic matters and the like, and the harmful impurities have great influence on the performance of the phosphogypsum product. The domestic and foreign phosphogypsum pretreatment methods mainly comprise the following steps: 1) Washing and purifying to remove impurities such as water-soluble phosphorus, fluorine and the like in the phosphogypsum; 2) Lime is neutralized to convert harmful impurities such as phosphorus, fluorine and the like into inert substances; 3) Calcining and purifying to remove eutectic phosphorus and organic matters; 4) Treating the phosphogypsum by a ball milling method, and changing the crystal morphology and the grain size distribution of the phosphogypsum; 5) And the fine particle impurities and the coarse particle impurities with higher impurity content in the phosphogypsum can be removed through screening and purification. The common method mainly removes impurities such as soluble phosphorus, fluorine, eutectic phosphorus and the like, but can not remove impurities such as organic matters, iron, silicon dioxide and the like which mainly affect whiteness and purity in the phosphogypsum, and the calcining method can remove the organic matters in the phosphogypsum but has higher cost.
Organic carbon and iron impurities in the phosphogypsum have great influence on the whiteness of the phosphogypsum, so that the application value of the phosphogypsum in the aspect of building materials is influenced, and the phenomenon of red color generation (caused by converting bivalent iron impurities into red iron oxide) is generated when the phosphogypsum is prepared into the anhydrous gypsum at high temperature. Meanwhile, the hardness of silicon dioxide in the phosphogypsum is high, which is not beneficial to grinding when the rear end of the phosphogypsum is applied, and the activity of calcium oxide prepared by decomposing the phosphogypsum can be reduced. Theoretically, the dissociation degree of the calcium sulfate dihydrate monomer in the phosphogypsum is high, and impurities such as organic matters, iron impurities, silicon dioxide and the like can be separated from the calcium sulfate dihydrate by adopting a flotation method. The phosphogypsum produced by the acid preparation by the dihydrate method has the advantages of fine granularity and serious argillization, the ratio of the phosphogypsum to a 400-mesh sieve is usually more than 25 percent, and bubbles with larger grain diameter are generated by using the traditional flotation machine for flotation, and are between 0.1 and 1mm, so that the separation difficulty of fine-grained minerals is higher.
Disclosure of Invention
In view of the above analysis, the embodiment of the present invention aims to provide a phosphogypsum whitening and purifying process, which is used for solving the problem of insufficient impurity removal and purification of the existing phosphogypsum whitening and purifying process.
The main purpose of the invention is realized by the following technical scheme:
the invention provides a whitening and purifying process of phosphogypsum, which comprises the following steps:
step 1: connecting four cyclone-static microbubble flotation columns in series;
step 2: conveying the phosphogypsum to be treated to a size mixing tank, and mixing to obtain phosphogypsum pulp;
and step 3: the phosphogypsum ore pulp in the size mixing tank is driven into a first cyclone-static microbubble flotation, a reverse flotation reagent is added, and a first reverse flotation is carried out to obtain a first ore pulp; pumping the first ore pulp into a second cyclone-static microbubble flotation column, adding a reverse flotation agent which is the same as that of the first reverse flotation, and performing second reverse flotation to obtain second ore pulp;
and 4, step 4: pumping the second ore pulp into a third cyclone-static microbubble flotation column, adding a positive flotation agent, and performing primary positive flotation to obtain third ore pulp; pumping the third ore pulp into a fourth rotational flow-static microbubble flotation column, adding a positive flotation agent which is the same as that of the first positive flotation, and performing second positive flotation to obtain phosphogypsum concentrate;
and 5: and pumping the phosphogypsum concentrate obtained after twice reverse flotation and twice forward flotation into plate-and-frame filter pressing equipment for dehydration, and drying after the dehydration is finished to obtain the whitened and purified phosphogypsum.
Further, in the step 2, the pH value of the phosphogypsum ore pulp is 1-3, and the mass concentration of the ore pulp is 30-40%.
Further, in the step 3, the reverse flotation reagent is tributyl phosphate, terpineol, fatty alkyl (R) with carbon chain length C 12 ~C 20 Fatty primary amine (R-NH) of (2) 2 ) And fatty alkyl (R) carbon chain length C 12 ~C 20 Dimethyl tertiary amine (R-N (CH) 3 ) 2 ) The compound preparation of (1).
Further, in the step 3, the primary aliphatic amine (R-NH) in the reverse flotation reagent 2 ) Is twelveOne or more of amine, tetradecylamine, hexadecylamine and octadecylamine;
dimethyl tertiary amine (R-N (CH) in the reverse flotation reagent 3 ) 2 ) Is one or more of dodecyl dimethyl tertiary amine, tetradecyl dimethyl tertiary amine, hexadecyl dimethyl tertiary amine and octadecyl dimethyl tertiary amine.
Further, in the step 3, the raw material composition of the reverse flotation reagent is as follows by mass percent: tributyl phosphate: 5% -15%; terpineol: 5% -15%; the carbon chain length of the fatty alkyl (R) being C 12 ~C 20 A range of primary aliphatic amines (R-NH) 2 ): 30% -60%; the carbon chain length of the fatty alkyl (R) being C 12 ~C 20 A range of dimethyl tertiary amines (R-N (CH) 3 ) 2 ):20%~40%。
Furthermore, in the step 3, the dosage of the first reverse flotation reagent is 60 g/t-160 g/t, and the dosage of the second reverse flotation reagent is 0 g/t-100 g/t.
Further, in the step 3, the total retention time of the ore pulp of the first reverse flotation and the ore pulp of the second reverse flotation is 10-15 min.
Further, in the step 4, the positive flotation reagent is fatty alkyl (R) with a carbon chain length of C 12 ~C 20 Alkyl propyl ether amine (R-O-CH) 2 CH 2 CH 2 NH 2 ) A compound medicament of dodecylamine and 0.5 to 5.0 mass percent of acetic acid solution.
Further, the positive flotation reagent comprises the following raw materials in percentage by mass: the carbon chain length of the fatty alkyl (R) being C 12 ~C 20 Alkyl propyl ether amine (R-O-CH) 2 CH 2 CH 2 NH 2 ): 30% -60%; lauryl amine: 39.6 to 63.3 percent; 0.5-5.0% of acetic acid solution by mass percent: 10.4 to 16.7 percent.
Further, in the step 4, the alkyl propyl ether amine (R-O-CH) in the positive flotation reagent 2 CH 2 CH 2 NH 2 ) Is dodecyl propyl ether amine, tetradecyl propyl ether amine, hexadecyl propyl etherOne or more of amine and octadecyl propyl ether amine.
Compared with the prior art, the invention can realize at least one of the following beneficial effects:
1. the invention adopts the cyclone-static microbubble flotation column as a pilot flotation device (the treatment capacity of the phosphogypsum is 3600 tons/year), is more matched with the particle size distribution characteristics of the phosphogypsum (the proportion of fine-fraction minerals under a 400-mesh sieve is more than 25%, the particle size is finer, and the proportion of coarse-fraction minerals on a 100-mesh sieve is about 20%), has better separation effect compared with the traditional flotation machine, utilizes the cyclone-static microbubble flotation column to carry out double-reverse double-positive flotation on the phosphogypsum, improves the whiteness from 35% to 74.5%, obviously improves the whiteness, and is far higher than the whiteness improvement effect of the double-reverse double-positive flotation by using the traditional flotation machine (for example, improves the whiteness from 35% to 58.2%).
2. The invention selects two working sections of 'two-reverse two-positive' to whiten and purify the phosphogypsum (desiliconization, decarbonization and deferrization), and the reverse flotation working section can remove fine-grained impurities such as organic carbon, iron impurities and the like which influence the whiteness of the phosphogypsum, thereby greatly improving the whiteness of the phosphogypsum; the direct flotation section can remove coarse-grained impurities such as silicon dioxide and part of iron impurities which affect the purity of the phosphogypsum, greatly improve the purity of the phosphogypsum and further improve the whiteness of the phosphogypsum; the purification processes of the two sections are set according to the characteristics of fine-fraction impurities and coarse-fraction impurities (the proportion of fine-fraction minerals under a 400-mesh sieve is more than 25%, the whiteness is lower and about 10%, the fine-fraction minerals contain a large amount of organic matters and iron impurities, and the proportion of coarse-fraction minerals on a 100-mesh sieve is about 20%), so that the purification processes meet the size distribution characteristics of the phosphogypsum and the distribution characteristics of the impurities.
3. The reverse flotation agent adopted in the invention is tributyl phosphate, terpineol and fatty alkyl (R) with the carbon chain length of C 12 ~C 20 Primary and fatty alkyl (R) carbon chain lengths in the range of C 12 ~C 20 Dimethyl Tertiary amine (R-N (CH) within the range 3 ) 2 ) The compounded reagent can remove organic carbon in the phosphogypsum, has obvious effect of removing iron impurities in the phosphogypsum, and can remove more than 70 percent of the iron impurities in the phosphogypsum only in the reverse flotation working section. Removing organic carbon with the existing phosphogypsumCompared with the flotation reagent, the flotation reagent has higher organic carbon selectivity and less dosage. The positive flotation agent is fatty alkyl (R) with carbon chain length of C 12 ~C 20 Alkyl propyl ether amine (R-O-CH) within the range 2 CH 2 CH 2 NH 2 ) The flotation reagent has the advantages of strong phosphogypsum collecting capacity, high selectivity and small using amount. The two reagents are less in dosage, wide in raw material source and low in economic value, the cost of the phosphogypsum flotation reagent is not higher than 10 yuan/ton, the flotation cost is not higher than 30 yuan/ton of phosphogypsum, compared with the current common washing purification operation cost of the phosphogypsum which is higher than 35 yuan/ton, under the condition that the economic cost difference is not large, organic carbon, iron impurities and silicon dioxide in the phosphogypsum can be removed, the whiteness of the phosphogypsum is remarkably improved, relatively good economic benefit is achieved, good technical indexes are achieved, the common washing purification cannot remove the organic carbon, iron impurities and the silicon dioxide in the phosphogypsum, and the whiteness of the phosphogypsum cannot be improved.
4. According to the invention, a rotational flow-static microbubble flotation column is used as a flotation device, the flotation column has a good mineralization effect on phosphogypsum in flotation, a flotation process combining 'two-reverse two-positive' flotation is adopted, and the reverse flotation can remove organic carbon, iron impurities and part of silicon dioxide in the phosphogypsum, so that the whiteness of the phosphogypsum is greatly improved; the positive flotation can thoroughly remove silicon dioxide in the phosphogypsum, further remove iron impurities and greatly improve the purity of the phosphogypsum. The whiteness of the phosphogypsum raw ore is 35 percent (dried at 45 ℃), and the grade (by CaSO) 4 .2H 2 Calculated as O) is 90 percent, and SiO is added 2 3.98% of iron impurity (Fe) 2 O 3 Calculated by 0.38 percent, the whiteness of the phosphogypsum concentrate can be improved to 74.5 percent (dried at 45 ℃) and the grade (calculated by CaSO) by flotation 4 .2H 2 Calculated as O) to 98.2 percent, siO 2 The content is reduced to 0.5 percent, and iron impurities (Fe) 2 O 3 Calculated) is reduced to 0.06 percent, the yield of the phosphogypsum concentrate is 75 percent, and the recovery rate (calculated as CaSO) 4 .2H 2 Calculated as O) is 81.83 percent.
5. The phosphogypsum is subjected to 'double-reverse double-positive' flotation treatment to obtain high-quality phosphogypsum with the whiteness of 74.5 percent and the purity of 98.2 percent, the whiteness of the beta gypsum prepared by the phosphogypsum can reach more than 80 percent, and the problem that the surface of the beta gypsum is blackened (organic carbon) when the beta gypsum is used as a self-leveling product is solved due to the removal of the organic carbon, so that the product performance of the beta gypsum is improved.
6. The phosphogypsum can be subjected to flotation treatment to obtain high-quality phosphogypsum with the whiteness of 74.5 percent and the purity of 98.2 percent, the whiteness of the anhydrous gypsum prepared by the phosphogypsum is about 85 percent (the anhydrous gypsum prepared by the original gypsum contains iron impurities turns red, and the whiteness is only about 43 percent), the problem of the red of the anhydrous gypsum prepared by the original gypsum is solved, and the application range of phosphogypsum products is widened.
7. According to the invention, the phosphogypsum is subjected to flotation treatment, so that high-quality phosphogypsum with the whiteness of 74.5% and the purity of 98.2% can be obtained, the physical and chemical properties of the phosphogypsum are improved, and the improvement of the whiteness and the purity is specifically shown, and organic carbon, iron impurities and silicon dioxide are effectively removed. The application range of the rear end of the phosphogypsum is widened, the iron impurities are removed, the red phenomenon of high-temperature anhydrous gypsum is avoided, the application range of the anhydrous gypsum is greatly expanded, and the application of the phosphogypsum is expanded to the fields of gypsum lines, ceramic molds, putty powder and the like due to the improvement of whiteness.
In the invention, the technical schemes can be combined with each other to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.
Drawings
The drawings, in which like reference numerals refer to like parts throughout, are for the purpose of illustrating particular embodiments only and are not to be considered limiting of the invention.
FIG. 1 is a schematic diagram of the separation principle of a cyclone-static microbubble flotation column adopted by the invention;
FIG. 2 is a flow chart of the phosphogypsum whitening and purifying flotation process of the invention;
FIG. 3 is a schematic view of a pilot system flotation process of a cyclone-static microbubble flotation column according to the present invention;
FIG. 4 is a comparison of the phosphogypsum before and after whitening and purification treatment according to example 1 of the present invention;
FIG. 5 is a comparative graph of the inventive example 1 flotation treated phosphogypsum and raw phosphogypsum prepared anhydrite;
figure 6 is a comparison of XRD patterns of raw phosphogypsum ore and concentrate of example 1 of the present invention.
Detailed Description
The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form a part hereof, and which together with the embodiments of the invention serve to explain the principles of the invention and not to limit its scope.
In order to solve the problem of insufficient impurity removal and purification of solid waste phosphogypsum in the field of phosphorus chemical industry, the invention provides a phosphogypsum whitening and purifying process, wherein a rotational flow-static micro-bubble flotation column is selected as flotation equipment, and the phosphogypsum is whitened and purified (desiliconization, decarbonization and deferrization) by a twice reverse flotation-twice forward flotation process.
The whitening and purifying process of the phosphogypsum comprises the following steps:
step 1: connecting four cyclone-static microbubble flotation columns in series;
step 2: conveying the phosphogypsum to be treated to a size mixing tank, and mixing to obtain phosphogypsum pulp;
and 3, step 3: the phosphogypsum ore pulp in the size mixing tank is driven into a first cyclone-static microbubble flotation, a reverse flotation reagent is added, and a first reverse flotation is carried out to obtain a first ore pulp; pumping the first ore pulp into a second cyclone-static microbubble flotation column, adding a reverse flotation reagent which is the same as that of the first reverse flotation, and performing second reverse flotation to obtain second ore pulp;
and 4, step 4: pumping the second ore pulp into a third cyclone-static microbubble flotation column, adding a positive flotation reagent, and performing primary positive flotation to obtain third ore pulp; pumping the third ore pulp into a fourth rotational flow-static microbubble flotation column, adding a positive flotation agent which is the same as that of the first positive flotation, and performing the second positive flotation to obtain phosphogypsum concentrate;
and 5: and pumping the phosphogypsum concentrate obtained after twice reverse flotation and twice direct flotation into plate-and-frame filter pressing equipment for dehydration, and drying after dehydration to obtain the whitened and purified phosphogypsum.
Specifically, the main components of the solid waste phosphogypsum generated in the field of phosphorus chemical industry are below 200 meshes (75 microns), the proportion of the main components under a 400 mesh (38 microns) sieve is more than 25 percent, and the particle size is fine. Exemplary, particle size distribution of phosphogypsum to be treated: the proportion of fine-fraction minerals under a 400-mesh sieve is more than 25 percent, the whiteness is lower and is about 10 percent, and the fine-fraction minerals contain a large amount of organic matters and iron impurities; the coarse fraction mineral on a 100-mesh sieve accounts for about 20 percent, has low whiteness of about 20 percent, and contains a large amount of siliceous impurities and iron impurities.
When the flotation column is adopted for separation, the phosphogypsum does not need to be ground according to the particle size distribution characteristics and the impurity distribution condition of the phosphogypsum and can directly enter the flotation column for separation. When the rotational flow-static microbubble flotation column is used as pilot flotation equipment, the treatment capacity of phosphogypsum is 3600 tons/year.
The invention adopts a pilot flotation system of a rotational flow-static microbubble flotation column, and carries out two-reverse two-positive flotation on phosphogypsum by using the rotational flow-static microbubble flotation column, wherein the pilot flotation system comprises a slurrying system, a flotation zone of the flotation column and a dewatering zone (see attached figure 3), the flotation zone of the flotation column comprises a plurality of rotational flow-static microbubble flotation columns, the rotational flow-static microbubble flotation column comprises an aeration quantity generation regulating valve, a foam collecting tank, a microbubble generator, a circulating middling outlet pipe, a tailing outlet pipe, a rotational flow zone and a static flotation zone (see attached figure 1), the aeration quantity generation regulating valve is used for completing the regulation of air quantity, the foam collecting tank is used for completing the foam collection, the microbubble generator is used for completing the microbubble generation, a mixing mineralization pipe is used for completing the mineralization of the phosphogypsum, the circulating middling outlet pipe is used for completing the output, the tailing outlet pipe is used for completing the tailing output, the rotational flow zone is used for completing the rotational flow mineralization and separation of the phosphogypsum, and the static flotation zone is used for completing the static flotation.
The cyclone-static microbubble flotation column flotation process is shown in figure 1, and the cyclone-static microbubble flotation column separation method comprises three parts of column flotation, cyclone separation and pipe flow mineralization.
Column flotation is carried out in a static flotation area positioned in the upper area of the whole column body, the flotation principle of countercurrent collision mineralization is adopted, separation of fine materials is realized in a static separation environment with low turbulence, and the effects of rough separation and fine separation are achieved in the whole column flotation method; cyclone separation is performed in a cyclone zone located below the static flotation zone. Feeding materials from the upper part of a static flotation area, generating micro bubbles by a micro bubble generator, then entering the static flotation area from the lower part of the static flotation area, performing column flotation on the materials, then entering a cyclone area below the static flotation area, performing cyclone separation, and performing column flotation and cyclone separation sequentially from top to bottom to form a main body of the cyclone-static micro bubble flotation column separation method. Therefore, the cyclone flotation not only provides a high-efficiency mineralization mode, but also greatly reduces the lower limit of the flotation granularity, greatly improves the flotation speed, and strengthens the separation and recovery of the cyclone separation section as the supplement of the surface flotation. Pipe flow mineralization utilizes the jet principle, and a gas-solid-liquid three-phase system of circulating middlings is formed in pipe flow by introducing gas and crushing into bubbles, so that high turbulence mineralization is realized. The cyclone-static microbubble flotation column can generate nano-scale bubbles and microbubbles with the size of less than 200 mu m, and is more suitable for flotation of fine-grained phosphogypsum compared with bubbles generated by a traditional flotation machine within the range of 0.1-1 mm.
Specifically, in the step 2, the phosphogypsum is new-emission phosphogypsum of a phosphating plant, the pH value is 1-3, the stockpiling time is 0-6 months, the mass concentration of the prepared slurry is 30-40%, and the temperature is normal temperature.
Common process water and phosphogypsum are mixed, and the process water is added according to a certain proportion according to the weight of the phosphogypsum to be treated, so that the concentration of the prepared mineral slurry is ensured to be 30-40%, the dispersion of the phosphogypsum is better in the concentration range, and the collecting capability and the sorting performance of the medicament are better; according to the test, when the pH value of the ore pulp is 1-3, the reverse flotation impurity removal whitening effect is good, and the reverse flotation concentrate yield is high. The phosphogypsum is derived from a phosphoric acid preparation process, the phosphogypsum contains free acid (phosphoric acid, sulfuric acid and the like), the original pH value of phosphogypsum ore pulp is 2.0-2.5, and the pH value of the ore pulp can meet the requirement of the pH range of the reverse flotation effect after size mixing is finished, so that the pH value of the ore pulp does not need to be adjusted in the flotation process.
Specifically, in step 3, the reverse flotation reagent is tributyl phosphate, terpineol, fatty alkyl (R) with carbon chain length of C 12 ~C 20 Fatty primary amine (R-NH) of 2 ) And fatty alkyl (R) carbon chain length C 12 ~C 20 Dimethyl tertiary amine (R-N (CH) 3 ) 2 ) The compound preparation of (1). The reverse flotation reagent comprises the following raw materials in percentage by mass: tributyl phosphate: 5% -15%; terpineol: 5% -15%; the carbon chain length of the fatty alkyl (R) being C 12 ~C 20 Range of primary aliphatic amines (R-NH) 2 ): 30% -60%; the carbon chain length of the fatty alkyl (R) is C 12 ~C 20 Range of dimethyl tertiary amines (R-N (CH) 3 ) 2 ): 20 to 40 percent. The reverse flotation reagent can remove organic carbon, iron impurities and other impurities which mainly affect the whiteness of the phosphogypsum, increase the whiteness of the phosphogypsum and remove a part of silicon dioxide impurities.
Primary aliphatic amine (R-NH) in the reverse flotation reagent 2 ) One or more of laurylamine, tetradecylamine, hexadecylamine and octadecylamine; dimethyl tertiary amine (R-N (CH) in the reverse flotation reagent 3 ) 2 ) Is one or more of dodecyl dimethyl tertiary amine, tetradecyl dimethyl tertiary amine, hexadecyl dimethyl tertiary amine and octadecyl dimethyl tertiary amine.
Specifically, in the step 3, the dosage of the first reverse flotation reagent is 60-160 g/t, and the dosage of the second reverse flotation reagent is 0-100 g/t. The dosage of the first reverse flotation reagent is lower than 60g/t, the impurity removal effect is poor, the whiteness is not greatly increased, and the second reverse flotation reagent is reduced because of the residue of the first reverse flotation reagent. The total amount of the agents used in the two reverse flotation processes is not higher than 260g/t, the total amount is higher than 260g/t, the whiteness of the phosphogypsum flotation product is almost unchanged, and the cost is increased due to the fact that the amount of the agents used in the reverse flotation processes is continuously increased. The whiteness of the phosphogypsum can be improved from 35% to 57% by the first reverse flotation, and the whiteness can be improved from 57% to 63% by the second reverse flotation.
Compared with the existing flotation reagent for removing organic carbon from phosphogypsum, the flotation reagent has higher organic carbon selectivity, less dosage which is less than 260g/t of phosphogypsum, and can completely remove iron impurities in the phosphogypsum and remove more than 70 percent of the iron impurities in the phosphogypsum.
Specifically, in the step 3, the total retention time of the ore pulp is 10-15 min, the retention time is too short, the tailing (foam) yield is low, the quality of the concentrate is reduced, the tailing (foam) yield is high, and the concentrate yield is too low. Preferably, in the reverse flotation section, the total retention time of the ore pulp is 15min.
Specifically, in step 4, the positive flotation reagent is fatty alkyl (R) with a carbon chain length of C 12 ~C 20 Alkyl propyl ether amine (R-O-CH) 2 CH 2 CH 2 NH 2 ) A compound preparation of laurylamine and an acetic acid solution with the mass fraction of 0.5 to 5.0 percent. The positive flotation reagent comprises the following raw materials in percentage by mass: the carbon chain length of the fatty alkyl (R) being C 12 ~C 20 Alkyl propyl ether amine (R-O-CH) 2 CH 2 CH 2 NH 2 ): 30% -60%; lauryl amine: 39.6% -63.3%; 0.5-5.0% of acetic acid solution by mass percent: 10.4 to 16.7 percent. The alkyl propyl ether amine (R-O-CH) in the direct flotation reagent 2 CH 2 CH 2 NH 2 ) Is one or more of dodecyl propyl ether amine, tetradecyl propyl ether amine, hexadecyl propyl ether amine and octadecyl propyl ether amine. The direct flotation reagent can remove silicon dioxide which mainly influences the purity of the phosphogypsum and further remove the silicon dioxideRemoving impurities such as iron impurities, increasing the purity of the phosphogypsum and further improving the whiteness of the phosphogypsum.
In the step 4, the dosage of the first direct flotation agent is 160-260 g/t, and the dosage of the second direct flotation agent is 0-100 g/t. The dosage of the first direct flotation reagent is lower than 160g/t, all phosphogypsum cannot be effectively captured and floated, and the final concentrate yield of the phosphogypsum is low; and the amount of the second positive flotation reagent is reduced due to the residue of the first positive flotation reagent. The total amount of the chemical used in the two forward flotation processes is not higher than 360g/t, and the excessive use of the chemical used in the forward flotation processes can result in the overhigh yield of the concentrate, the reduction of the quality and the increase of the cost. The first positive flotation can improve the whiteness of the phosphogypsum from 63% to 70.5%, and the second reverse flotation can improve the whiteness from 70.5% to 74.5%. The direct flotation reagent has strong phosphogypsum collecting capacity, high selectivity and small dosage, the dosage is less than 360g/t phosphogypsum, simultaneously, the silicon dioxide and the iron impurities in the phosphogypsum are completely removed, more than 80 percent of siliceous impurities in the phosphogypsum can be removed, the iron impurity content in the phosphogypsum is further reduced, and the purity of the phosphogypsum (by using CaSO) 4 .2H 2 O content) is increased from 93 percent after reverse flotation to about 98.2 percent.
Specifically, in the step 4, in the first positive flotation and the second positive flotation, the total retention time of the ore pulp is 10-15 min, the too short retention time can result in the too low yield of the concentrate (froth), and the too long retention time can result in the too high yield of the concentrate (froth) and the reduced quality of the concentrate. Preferably, in the positive flotation section, the total retention time of the ore pulp is 15min.
The two reagents are low in dosage, wide in raw material source and low in economic value, the cost of the phosphogypsum flotation reagent is not higher than 10 yuan/ton, the flotation cost is not higher than 30 yuan/ton of phosphogypsum, and compared with the existing common washing purification operation cost of the phosphogypsum which is higher than 35 yuan/ton, under the condition that the economic cost difference is not large, organic carbon, iron impurities and silicon dioxide in the phosphogypsum can be removed relatively thoroughly, the whiteness of the phosphogypsum is improved remarkably, relatively good economic benefit is achieved, good technical indexes are achieved, the common washing purification cannot remove the organic carbon, the iron impurities and the silicon dioxide in the phosphogypsum, and the whiteness of the phosphogypsum cannot be improved.
Specifically, in the step 5, the dehydration equipment is a plate-and-frame filter pressing system, the phosphogypsum is dried after dehydration, the drying temperature of the phosphogypsum is 40-50 ℃, only free water can be removed in the temperature range, the loss of crystal water of the phosphogypsum cannot occur, and the whiteness of the dried phosphogypsum is measured by a blue-light whiteness meter. Preferably, the drying temperature of the phosphogypsum is 45 ℃.
The whiteness of the phosphogypsum concentrate treated by the phosphogypsum whitening and purifying process is improved to 74.5 percent (dried at 45 ℃) to the maximum, and the grade is improved to CaSO 4 .2H 2 Calculated as O) is increased to 98.2 percent, the whiteness of the beta gypsum prepared by the phosphogypsum can reach more than 80 percent, and the problem that the surface of the beta gypsum is blackish (organic carbon) when the beta gypsum is used as a self-flowing ordinary time is solved due to the removal of the organic carbon, and the product performance of the beta gypsum is improved. The whiteness of the anhydrous gypsum prepared by the phosphogypsum is about 85% (the anhydrous gypsum prepared by the original gypsum contains iron impurities turns red, and the whiteness is only about 43%), so that the problem of red turning after the anhydrous gypsum is prepared by the original gypsum is solved, and the application range of phosphogypsum products is widened.
In the following examples, the phosphogypsum used is the phosphogypsum by-product of a certain phosphate rock in Guizhou, the stacking time is 0-6 months, the whiteness is 35%, the pH value is 1-3, and the purity of the phosphogypsum (by CaSO) 4 .2H 2 Calculated as O) is 90 percent.
In the following examples, the whiteness of phosphogypsum is tested after drying, and is measured by blue light whiteness, and the drying temperature of the phosphogypsum is 45 ℃.
In the following examples, the flotation processes used are reverse flotation to remove organic carbon and iron impurities that mainly affect the whiteness of phosphogypsum, and forward flotation to remove silica and iron impurities that mainly affect the purity of phosphogypsum, and further increase the whiteness of phosphogypsum in forward flotation.
Example 1
The embodiment provides a phosphogypsum whitening and purifying process, and the process flow is shown in figure 2.
In this embodiment, the reverse flotation reagent is a compound reagent of tributyl phosphate, terpineol, dodecylamine and tetradecyl dimethyl tertiary amine, and the reverse flotation reagent comprises the following raw materials in percentage by mass: 10% of tributyl phosphate, 10% of terpineol, 50% of dodecylamine and 30% of tetradecyl dimethyl tertiary amine; the positive flotation reagent is a compound reagent of dodecyl propyl ether amine, dodecylamine and 0.5 to 5.0 mass percent of acetic acid solution, and the positive flotation reagent comprises the following raw materials in percentage by mass: 40 percent of dodecyl propyl ether amine, 47.5 percent of lauryl amine and 12.5 percent of acetic acid solution with the mass fraction of 0.5 to 5.0 percent.
Step 1: connecting four cyclone-static microbubble flotation columns in series, wherein the first two flotation columns are used for phosphogypsum reverse flotation, and the second two flotation columns are used for phosphogypsum direct flotation;
step 2: conveying the phosphogypsum to be treated to a size mixing tank through a belt, and mixing the phosphogypsum with common process water until the mass concentration of ore pulp is adjusted to 35%;
and step 3: a reverse flotation section: pumping the phosphogypsum ore pulp in the size mixing tank into a first cyclone-static microbubble flotation column, adding a reverse flotation reagent for carrying out first reverse flotation, wherein the dosage of the reagent is 100g/t, pumping the phosphogypsum ore pulp subjected to the first reverse flotation into a second cyclone-static microbubble flotation column, adding the reverse flotation reagent for carrying out second reverse flotation, and the dosage of the reagent is 30/t; the total retention time of the ore pulp of the two reverse flotations is 15min.
And 4, step 4: a positive flotation section: pumping the phosphogypsum rough and fine ore subjected to the secondary reverse flotation into a third rotational flow-static microbubble flotation column by using a pump, adding a positive flotation reagent, performing primary positive flotation, wherein the dosage of the reagent is 190g/t, pumping the phosphogypsum ore pulp subjected to the primary positive flotation into a fourth rotational flow-static microbubble flotation column, and performing secondary positive flotation; adding a positive flotation reagent in an amount of 30g/t; the retention time of the two positive flotation ore pulps is 15min.
And 5: a filtering section: pumping the phosphogypsum concentrate obtained after the second positive flotation treatment into plate-and-frame filtration dehydration equipment to complete dehydration, and drying at 45 ℃ to obtain the whitened and purified phosphogypsum.
The test result shows that the whiteness of the phosphogypsum raw ore is 35 percent (dried at 45 ℃), and the grade (by CaSO) 4 .2H 2 Calculated as O) is 90 percent, and SiO is added 2 3.98% of iron impurity (Fe) 2 O 3 Calculated by 0.38 percent, the whiteness of the phosphogypsum concentrate is improved to 74.5 percent (dried at the temperature of 45 ℃) and the grade (calculated by CaSO) is improved by four times of flotation of two opposite sides and two positive sides 4 .2H 2 Calculated as O) to 98.2 percent, siO 2 The content is reduced to 0.5 percent, and iron impurities (Fe) 2 O 3 Calculated) is reduced to 0.06 percent, the yield of the phosphogypsum concentrate is 75 percent, and the recovery rate (calculated as CaSO) 4 .2H 2 Calculated as O) is 81.83 percent.
Example 2-1
In the step 2, conveying the phosphogypsum to be treated to a repulping tank through a belt, and carrying out size mixing by using common process water, wherein the mass concentration of ore pulp is 30%; the remaining process steps and parameters were the same as in example 1.
The test result shows that: the whiteness of the phosphogypsum concentrate is improved to 72.6 percent (drying at 45 ℃), and the grade of the phosphogypsum is improved by CaSO 4 .2H 2 O) is increased from 90% to 98%, the yield of concentrate is 65%, and the recovery rate (calculated as CaSO) 4 .2H 2 Calculated as O) is 78.77 percent.
Examples 2 to 2
In the step 2, conveying the phosphogypsum to be treated to a size mixing tank through a belt, and mixing the phosphogypsum with common process water to obtain the pulp with the mass concentration of 33%; the remaining process steps and parameters were the same as in example 1.
The test result shows that: the whiteness of the phosphogypsum concentrate is improved to 73.5 percent (drying at 45 ℃), and the grade of the phosphogypsum is improved by CaSO 4 .2H 2 Calculated as O) increased from 90% to 97.5%, the concentrate yield was 67%, and the recovery rate (in terms of CaSO) 4 .2H 2 Calculated as O) is 79.58 percent.
Examples 2 to 3
In the step 2, the phosphogypsum to be treated is conveyed to a repulping tank through a belt, and common process water is used for size mixing, wherein the concentration of ore pulp is 40%; the remaining process steps and parameters were the same as in example 1.
The test result shows that: the whiteness of the phosphogypsum concentrate is improved to 73.7 percent (dried at 45 ℃), and the grade of the phosphogypsum is improved by CaSO 4 .2H 2 Calculated as O) is increased from 90 percent to 97.5 percent, the yield of the concentrate is 76 percent, and the recovery rate (calculated as CaSO) 4 .2H 2 Calculated as O) is 80.64 percent.
Example 3-1
In the step 3, in the reverse flotation section, the total retention time of ore pulp subjected to two times of reverse flotation is 10min; in the step 4, in the positive flotation section, the total retention time of ore pulp in the two positive flotation processes is 10min. The remaining process steps and parameters were the same as in example 1.
The test result shows that: the whiteness of the phosphogypsum concentrate is improved to 72.7 percent (dried at 45 ℃), and the grade of the phosphogypsum is improved by CaSO 4 .2H 2 Calculated as O) increased from 90% to 97.8%, the yield of concentrate was 68%, and the recovery rate (in terms of CaSO) 4 .2H 2 Calculated as O) is 71.78 percent.
Example 3-2
In the step 3, in the reverse flotation section, the total retention time of ore pulp in the two reverse flotation processes is 13min; in the step 4, in the positive flotation section, the total retention time of ore pulp in two positive flotation processes is 13min. The remaining process steps and parameters were the same as in example 1.
The test result shows that: the whiteness of the phosphogypsum concentrate is improved to 73.8 percent (drying at 45 ℃), and the grade of the phosphogypsum is improved by CaSO 4 .2H 2 Calculated as O) increased from 90% to 97.8%, the concentrate yield was 69%, and the recovery rate (in terms of CaSO) 4 .2H 2 Calculated as O) is 75.56 percent.
Example 4-1
In the embodiment, the dosage of the first reverse flotation reagent is 60g/t, and the dosage of the second reverse flotation reagent is 0g/t; the dosage of the first direct flotation reagent is 160g/t, and the dosage of the second direct flotation reagent is 0g/t; the remaining process steps and parameters were the same as in example 1.
The test result shows that the drying whiteness of the phosphogypsum before flotation is 35 percent, the drying whiteness of the phosphogypsum concentrate after flotation is 71.6 percent, and the purity of the phosphogypsum after flotation (by CaSO) 4 .2H 2 Calculated as O) increased from 90% to 97.3%, yield of phosphogypsum concentrate was 73%, recovery rate (in terms of CaSO) 4 .2H 2 Calculated as O) is 80.58 percent.
Example 4-2
In the embodiment, the dosage of the first reverse flotation reagent is 160g/t, and the dosage of the second reverse flotation reagent is 100g/t; the dosage of the first direct flotation reagent is 260g/t, and the dosage of the second direct flotation reagent is 100g/t; the remaining process steps and parameters were the same as in example 1.
The test result shows that the drying whiteness of the phosphogypsum before flotation is 35 percent, the drying whiteness of the phosphogypsum concentrate after flotation is 72.8 percent, and the purity of the phosphogypsum after flotation (by CaSO) 4 .2H 2 Calculated as O) is increased from 90 percent to 97.6 percent, the yield of the phosphogypsum concentrate is 74 percent, and the recovery rate (calculated as CaSO) 4 .2H 2 Calculated as O) is 80.89 percent.
Example 5-1
In this example, compared with example 1, different flotation indexes were obtained by changing the raw material component mass percentage of the flotation agent.
In the step 3, the reverse flotation reagent is a compound reagent of tributyl phosphate, terpineol, dodecylamine and tetradecyl dimethyl tertiary amine, and the mass percentages of the reverse flotation reagent raw materials are respectively as follows: 15% of tributyl phosphate, 5% of terpineol, 50% of dodecylamine and 30% of tetradecyl dimethyl tertiary amine; the dosage of the first reverse flotation is 100g/t, and the dosage of the second reverse flotation reagent is 30g/t.
In the step 4, the positive flotation reagent is a compound reagent of dodecyl propyl ether amine, dodecylamine and 0.5-5.0% by mass of acetic acid solution, and the positive flotation reagent comprises the following raw materials in percentage by mass: 40 percent of dodecyl propyl ether amine, 47.5 percent of lauryl amine and 12.5 percent of acetic acid solution with the mass fraction of 0.5 to 5.0 percent; the dosage of the first direct flotation is 190g/t, and the dosage of the second direct flotation agent is 30g/t.
The remaining process steps and parameters were the same as in example 1.
The test result shows that the whiteness of the phosphogypsum raw ore is 35 percent (dried at 45 ℃), and the grade (by CaSO) 4 .2H 2 Calculated as O) is 90 percent and SiO is added 2 3.98% of iron impurity (Fe) 2 O 3 Calculated by 0.38 percent, the whiteness of the phosphogypsum concentrate is improved to 72.7 percent (dried at 45 ℃) and the grade (calculated by CaSO) through flotation 4 .2H 2 Calculated as O) is increased to 96.8 percent, siO 2 The content is reduced to 0.5 percent, and iron impurities (Fe) 2 O 3 Calculated by CaSO) to 0.09 percent, the yield of the phosphogypsum concentrate is 75.3 percent, and the recovery rate (calculated by CaSO) 4 .2H 2 Calculated as O) is 80.99 percent.
Example 5-2
In the step 3, the reverse flotation reagent is a compound reagent of tributyl phosphate, terpineol, dodecylamine and tetradecyl dimethyl tertiary amine, and the mass percentages of the reverse flotation reagent raw materials are respectively as follows: 15% of tributyl phosphate, 15% of terpineol, 30% of dodecylamine and 40% of tetradecyl dimethyl tertiary amine; the dosage of the first reverse flotation reagent is 100g/t, and the dosage of the second reverse flotation reagent is 30g/t.
In the step 4, the positive flotation reagent is a compound reagent of dodecyl propyl ether amine, lauryl amine and an acetic acid solution with the mass fraction of 0.5-5.0%, and the positive flotation reagent comprises the following raw materials in percentage by mass: 40 percent of dodecyl propyl ether amine, 47.5 percent of lauryl amine and 12.5 percent of acetic acid solution with the mass fraction of 0.5 to 5.0 percent; the dosage of the first direct flotation agent is 190g/t, and the dosage of the second direct flotation agent is 30g/t.
The remaining process steps and parameters were the same as in example 1.
The test result shows that the whiteness of the phosphogypsum raw ore is 35 percent (dried at 45 ℃), and the grade (by CaSO) 4 .2H 2 Calculated as O) is 90 percent and SiO is added 2 3.98% of iron impurity (Fe) 2 O 3 Calculated by weight percent) of 0.38 percent, the whiteness of the phosphogypsum concentrate is promoted to 72.5 percent (dried at 45 ℃) and the grade (calculated by CaSO) through flotation 4 .2H 2 Calculated as O) is increased to 96.5 percent, siO 2 The content is reduced to 0.55 percent, and iron impurities (Fe) 2 O 3 Calculated by CaSO) to 0.05 percent, the yield of the phosphogypsum concentrate is 76.8 percent, and the recovery rate (calculated by CaSO) 4 .2H 2 Calculated as O) is 82.35 percent.
Examples 5 to 3
In the step 3, the reverse flotation reagent is a compound reagent of tributyl phosphate, terpineol, dodecylamine and tetradecyl dimethyl tertiary amine, and the mass percentages of the reverse flotation reagent raw materials are respectively as follows: 10% of tributyl phosphate, 10% of terpineol, 50% of dodecylamine and 30% of tetradecyl dimethyl tertiary amine; the dosage of the first reverse flotation reagent is 100g/t, and the dosage of the second reverse flotation reagent is 30g/t.
In the step 4, the positive flotation reagent is a compound reagent of dodecyl propyl ether amine, dodecylamine and 0.5-5.0% by mass of acetic acid solution, and the positive flotation reagent comprises the following raw materials in percentage by mass: 50 percent of dodecyl propyl ether amine, 39.6 percent of lauryl amine and 10.4 percent of acetic acid solution with the mass fraction of 0.5 to 5.0 percent; the dosage of the first direct flotation is 190g/t, and the dosage of the second direct flotation agent is 30g/t.
The remaining process steps and parameters were the same as in example 1.
The test result shows that the whiteness of the phosphogypsum raw ore is 35 percent (dried at 45 ℃), and the grade (by CaSO) 4 .2H 2 Calculated as O) is 90 percent, and SiO is added 2 3.98% of iron impurity (Fe) 2 O 3 Calculated by 0.38 percent, the whiteness of the phosphogypsum concentrate is improved to 72.6 percent (dried at 45 ℃) and the grade (calculated by CaSO) through flotation 4 .2H 2 Calculated as O) is increased to 95.7 percent, and SiO is added 2 The content is reduced to 0.9 percent, and iron impurities (Fe) 2 O 3 Calculated) is reduced to 0.075 percent, the yield of the phosphogypsum concentrate is 74.5 percent, and the recovery rate (calculated as CaSO) 4 .2H 2 Calculated as O) is 79.22 percent.
Example 6
In the embodiment, a rotational flow-static micro-bubble flotation column is used as a flotation device, a double reverse-double positive flotation process is used for carrying out flotation on phosphogypsum, the dosage of a reverse flotation reagent is 2600g/t phosphogypsum (the dosage of the first reverse flotation reagent and the second reverse flotation reagent is respectively 20 times of the dosage of the traditional Chinese medicine in the embodiment 1), and the dosage of a positive flotation reagent is 220g/t phosphogypsum (the dosage of the first positive flotation reagent and the second positive flotation reagent is the same as the dosage of the traditional Chinese medicine in the embodiment 1); in this example, the reverse flotation reagent was oleic acid, and the forward flotation reagent was dodecylpropyl ether amine.
The test result shows that the drying whiteness of the phosphogypsum raw ore before flotation is 35 percent, the drying whiteness of the phosphogypsum concentrate after flotation is 65 percent (the drying temperature is 45 ℃), and the purity of the phosphogypsum after flotation is shown by CaSO 4 .2H 2 Calculated as O) is 96.1 percent, and the yield of the phosphogypsum concentrate is 76 percent.
Comparative example 1
In the embodiment, a flotation machine is used as a flotation device, and the rest adopted flotation process, reagent system and phosphogypsum raw materials are the same as those in the embodiment 1;
test results show that the drying whiteness of the phosphogypsum raw ore before flotation is 35%, the drying whiteness of the phosphogypsum concentrate after flotation is 58.2% (the drying temperature is 45 ℃) and the yield of the concentrate is 69%.
Comparative example 2-1
In this example, different numbers and series combinations of cyclone-static micro bubble flotation columns were used as compared to example 1.
In the embodiment, a rotational flow-static microbubble flotation column is used as a flotation device, 2 rotational flow-static microbubble flotation columns are connected in series, and phosphogypsum is floated by adopting a twice reverse flotation process, wherein the types and the use amounts of phosphogypsum raw materials and reagents of the twice reverse flotation process are the same as those of embodiment 1;
the test result shows that the drying whiteness of the phosphogypsum raw ore before flotation is 35 percent, the drying whiteness of the phosphogypsum concentrate after flotation is 63 percent (the drying temperature is 45 ℃), and the purity of the phosphogypsum after flotation is shown by CaSO 4 .2H 2 Calculated as O) is 93 percent, and the yield of the phosphogypsum concentrate is 89 percent.
Comparative examples 2 to 2
In the step 1, 2 cyclone-static microbubble flotation columns are connected in series, the first 1 flotation column is used for phosphogypsum reverse flotation, and the last 1 flotation column is used for phosphogypsum direct flotation. The phosphogypsum is floated by adopting a 'one-reverse-one-positive' process, and the rest process steps and parameters are the same as those in the example 1.
The test result shows that: the whiteness of the phosphogypsum raw ore is 35 percent (dried at 45 ℃), and the grade is CaSO 4 .2H 2 Calculated as O) is 90 percent, the whiteness of the phosphogypsum concentrate is improved to 59.6 percent (drying at 45 ℃) and the grade (calculated as CaSO) is improved through flotation 4 .2H 2 Calculated as O) increased to 95.7%.
Comparative examples 2 to 3
In the step 1, 3 cyclone-static microbubble flotation columns are connected in series, the first 2 flotation columns are used for phosphogypsum reverse flotation, and the last 1 flotation column is used for phosphogypsum forward flotation. The phosphogypsum was floated by a "two-reverse-one-positive" process, the remaining process steps and parameters being the same as in example 1.
The remaining process steps and parameters were the same as in example 1.
The test result shows that: the whiteness of the phosphogypsum raw ore is 35 percent (dried at 45 ℃), and the grade (by CaSO) 4 .2H 2 Calculated as O) is 90 percent, the whiteness of the phosphogypsum concentrate is improved to 64.5 percent (drying at 45 ℃) and the grade (calculated as CaSO) is improved through flotation 4 .2H 2 Calculated as O) to 96.2 percent.
Comparative examples 2 to 4
In the step 1, 3 cyclone-static microbubble flotation columns are connected in series, the first 1 flotation column is used for phosphogypsum reverse flotation, and the last 2 flotation columns are used for phosphogypsum direct flotation. The phosphogypsum is floated by adopting a 'one-reverse-two-positive' process, and the rest process steps and parameters are the same as those of the example 1. The remaining process steps and parameters were the same as in example 1.
The test result shows that: the whiteness of the phosphogypsum raw ore is 35 percent (dried at 45 ℃), and the grade (by CaSO) 4 .2H 2 Calculated as O) is 90 percent, the whiteness of the phosphogypsum concentrate is improved to 66.5 percent (dried at the temperature of 45 ℃) through flotation, and the grade (calculated as CaSO) 4 .2H 2 Calculated as O) increased to 96.8%.
Comparative example 3
In the embodiment, a flotation machine is used as a flotation device, and the rest adopted flotation process, reagent system and phosphogypsum raw materials are the same as those in the embodiment 6;
the test result shows that the drying whiteness of the phosphogypsum raw ore before flotation is 35%, the drying whiteness of the phosphogypsum concentrate after flotation is 50.2% (the drying temperature is 45 ℃), and the yield of the concentrate is 59%.
It can be seen from the comparison of example 1 and comparative example 1 that the cyclone-static microbubble flotation column has more advantages in phosphogypsum separation performance than the traditional flotation machine. Under the same flotation process and agent system, the quality phosphogypsum with the whiteness of 74.5 percent can be obtained by adopting the cyclone-static microbubble flotation column flotation, and the whiteness of the phosphogypsum concentrate obtained by the flotation machine is only 58.2 percent.
From comparative example 1 and comparative examples 2-1 to 2-4, it can be seen that the whiteness of 74.5% and the purity (in terms of CaSO) can be achieved in a two-reverse two-forward flotation process under the same flotation equipment conditions 4 .2H 2 O) is 98.2 percent, the phosphogypsum is obtained by changing different numbers of cyclone-static microbubble flotation columns and combining in a series mode, and performing 'two-reverse', 'one-reverse-one-positive', 'two-reverse-one-positive', and 'one-reverse-two-positive' processesThe whiteness and purity of the concentrate are far lower than those of the flotation process of 'two-reverse two-positive' in example 1, so that in order to obtain phosphogypsum with high whiteness and high purity, a flotation process of twice reverse flotation and twice positive flotation is adopted.
By comparing example 1 with example 6, it can be seen that under the same flotation equipment and two-reverse-two-direct flotation process conditions, the types and the amounts of the reverse flotation agent and the direct flotation agent in example 6 are different from those in example 1, and the obtained phosphogypsum has the drying whiteness of 65% and the purity (expressed as CaSO) 4 .2H 2 Calculated as O) is 96.1 percent, which is lower than the drying whiteness of 74.5 percent and the purity of 98.2 percent (calculated as CaSO) in example 1 4 .2H 2 Calculated by O), so that the reverse flotation agent adopted in the process has better economic applicability compared with oleic acid, and the direct flotation agent adopted in the process has better effect on CaSO in phosphogypsum compared with dodecyl propyl ether amine 4 .2H 2 O is more preferable.
From example 6 and comparative example 3, it can be seen that, when the phosphogypsum is floated by using the existing flotation agent and the rotational flow-static microbubble flotation column as the flotation device and the double-reverse-double-positive flotation process, the drying whiteness of the phosphogypsum is 65 percent and the purity is high (the CaSO is used 4 .2H 2 Calculated by O) is 96.1 percent, and compared with the traditional flotation machine, the cyclone-static microbubble flotation column has more advantages on the separation performance of the phosphogypsum. Under the same flotation process and agent system, the quality phosphogypsum with the whiteness of 65 percent can be obtained by adopting the prior art of the disclosed flotation agent and the cyclone-static microbubble flotation column flotation, and the whiteness of the phosphogypsum concentrate obtained by adopting the prior art of the disclosed flotation agent and the flotation machine is only 50.2 percent.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.

Claims (10)

1. The ardealite whitening and purifying process is characterized by comprising the following steps of:
step 1: connecting four cyclone-static microbubble flotation columns in series;
step 2: conveying the phosphogypsum to be treated to a size mixing tank, and mixing to obtain phosphogypsum pulp;
and 3, step 3: the phosphogypsum ore pulp in the size mixing tank is driven into a first cyclone-static microbubble flotation, a reverse flotation reagent is added, and a first reverse flotation is carried out to obtain a first ore pulp; pumping the first ore pulp into a second cyclone-static microbubble flotation column, adding a reverse flotation agent which is the same as that of the first reverse flotation, and performing second reverse flotation to obtain second ore pulp;
and 4, step 4: pumping the second ore pulp into a third cyclone-static microbubble flotation column, adding a positive flotation agent, and performing primary positive flotation to obtain third ore pulp; pumping the third ore pulp into a fourth rotational flow-static microbubble flotation column, adding a positive flotation agent which is the same as that of the first positive flotation, and performing second positive flotation to obtain phosphogypsum concentrate;
and 5: and pumping the phosphogypsum concentrate obtained after twice reverse flotation and twice forward flotation into plate-and-frame filter pressing equipment for dehydration, and drying after the dehydration is finished to obtain the whitened and purified phosphogypsum.
2. The whitening and purifying process according to claim 1, characterized in that in the step 2, the phosphogypsum pulp has a pH value of 1-3 and the pulp mass concentration is 30-40%.
3. The whitening and purifying process of claim 1, wherein in the step 3, the reverse flotation reagent is tributyl phosphate, terpineol, fatty alkyl (R) with carbon chain length C 12 ~C 20 Fatty primary amine (R-NH) of 2 ) And a fatty alkyl (R) carbon chain length of C 12 ~C 20 Dimethyl tertiary amine (R-N (CH) 3 ) 2 ) The compound preparation of (1).
4. The whitening purification process of claim 3, wherein in the step 3, the primary aliphatic amine (R-NH) in the reverse flotation reagent 2 ) Is composed ofOne or more of laurylamine, tetradecylamine, hexadecylamine and octadecylamine;
dimethyl tertiary amine (R-N (CH) in the reverse flotation reagent 3 ) 2 ) Is one or more of dodecyl dimethyl tertiary amine, tetradecyl dimethyl tertiary amine, hexadecyl dimethyl tertiary amine and octadecyl dimethyl tertiary amine.
5. The whitening and purifying process of claim 3, wherein in the step 3, the raw material composition of the reverse flotation reagent comprises the following components in percentage by mass: tributyl phosphate: 5% -15%; terpineol: 5% -15%; the carbon chain length of the fatty alkyl (R) is C 12 ~C 20 Range of primary aliphatic amines (R-NH) 2 ): 30% -60%; the carbon chain length of the fatty alkyl (R) is C 12 ~C 20 Range of dimethyl tertiary amines (R-N (CH) 3 ) 2 ):20%~40%。
6. The whitening and purifying process of claim 1, wherein in the step 3, the dosage of the first reverse flotation reagent is 60 g/t-160 g/t, and the dosage of the second reverse flotation reagent is 0 g/t-100 g/t.
7. The whitening and purifying process according to claim 1, wherein in the step 3, the total retention time of the ore pulps of the first reverse flotation and the second reverse flotation is 10 to 15min.
8. The whitening purification process according to claim 1, wherein in the step 4, the forward flotation agent is fatty alkyl (R) with carbon chain length of C 12 ~C 20 Alkyl propyl ether amine (R-O-CH) 2 CH 2 CH 2 NH 2 ) A compound medicament of dodecylamine and 0.5 to 5.0 mass percent of acetic acid solution.
9. The whitening and purifying process according to claim 8, wherein in the step 4, the raw material composition of the forward flotation agent is calculated by mass percentageComprises the following steps: the carbon chain length of the fatty alkyl (R) being C 12 ~C 20 Alkyl propyl ether amine (R-O-CH) 2 CH 2 CH 2 NH 2 ): 30% -60%; lauryl amine: 39.6 to 63.3 percent; 0.5-5.0% of acetic acid solution by mass percent: 10.4 to 16.7 percent.
10. The whitening purification process defined in any one of claims 8-9, wherein in the step 4, the alkyl propyl ether amine (R-O-CH) in the direct flotation reagent 2 CH 2 CH 2 NH 2 ) Is one or more of dodecyl propyl etheramine, tetradecyl propyl etheramine, hexadecyl propyl etheramine and octadecyl propyl etheramine.
CN202211301509.0A 2022-10-24 2022-10-24 Phosphogypsum whitening and purifying process Pending CN115957894A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024037127A1 (en) * 2023-06-05 2024-02-22 广东邦普循环科技有限公司 Method for decolorizing and whitening phosphogypsum

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024037127A1 (en) * 2023-06-05 2024-02-22 广东邦普循环科技有限公司 Method for decolorizing and whitening phosphogypsum

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