A method for extracting lithium from lithium-containing china clay ore by magnetic-flotation combination

Abstract

The present invention provides a method for the beneficiation of lithium-containing china clay ore by magnetic flotation combined with lithium extraction, adopts the process of "graded desludging-fine mud magnetic separation-magnetic product and graded coarse sand combined flotation" to carry out the beneficiation and recovery of lithium mica, adopts weak magnetic-strong magnetic step-by-step recovery of fine lithium mica in magnetic separation operation, adds YF3-2 as a dispersant and ZY-07 as a collector in flotation operation, performs flotation separation of lithium mica and gangue, improves the separation effect of lithium mica, and obtains feldspar powder with high whiteness, realizing efficient and comprehensive recovery of lithium-containing china clay ore. The present invention is a new method for beneficiation of lithium-containing china clay ore that is stable, efficient, has strong adaptability, good separation effect, high recovery index, and high product added value, and is suitable for promotion and application.

Description

Technical Field

[0001] The invention belongs to the technical field of ore dressing, and in particular relates to an ore dressing method for extracting lithium from lithium-containing porcelain clay ore by magnetic-flotation combination. Background Art

[0002] Lithium is an important strategic key metal and an indispensable raw material for energy storage batteries, power batteries, consumer device batteries, etc. Lepidolite in porcelain clay mines is an important lithium-containing mineral. This type of resource has the advantages of large resources, concentrated distribution, and good mining conditions. It has now become an important raw material support for my country's lithium salt industry. This type of resource is found in granite pegmatite deposits. After long-term hydrothermal replacement and water-rock reaction, it shows different degrees of weathering and alteration. It is easy to become muddy in the crushing and grinding process of mineral processing. The ore mud has a strong adsorption and covering reaction on the flaky lepidolite minerals, which seriously deteriorates the flotation pulp environment. Traditional sodium silicate has poor inhibition effect on fine mud dispersion and low efficiency in eliminating metal ions in the pulp. Fatty amine cationic collectors are easily adsorbed on the surface of the ore mud, resulting in poor flotation separation of lepidolite and gangue minerals and reduced lithium mineral processing recovery rate.

[0003] The problem of fine mud's influence on the existing flotation reagent system of inhibitors, collectors, etc. is difficult to solve effectively. In order to reduce the influence of fine mud on the flotation of lithium mica, the ore dressing plant usually removes all the fine mud of -25μm or even -38μm, but the amount of lithium metal lost with the fine mud accounts for up to 20-25% of the original ore. According to statistics, the amount of lithium mica lost in fine mud by lithium mica dressing plants in Yichun, Jiangxi alone is as high as 500-1000 tons / year, and it will increase in the next few years. This not only causes a serious loss of lithium resources, but also a large amount of abandoned fine mud is stored, resulting in high safety risks and environmental hazards. It is urgent to develop a comprehensive utilization technology that is suitable for it.

[0004] The Chinese invention patent with the patent number CN 111298978 B and the name "A method for flotation of iron lithium mica without desludging" discloses a method for beneficiation of lithium mica. He proposed that the inhibitor sodium hexametaphosphate was mixed with the original ore and ball milled, and the roughing selection and two scavenging foams were combined and selected three times. The foam product obtained by combining the selected medium ore and reselecting was returned to the roughing operation after regrinding. This method realizes the flotation of lithium mica without desludging, but its essence is the "strong pulling and strong pressure" type for lithium mica sorting. The amount of inhibitors and collectors is large, which is easy to cause high foam and medium ore yields and large slurry circulation. The process of reselecting and regrinding the medium ore is complicated, and the reagent consumption and production operation difficulty are further increased. In addition, although this method uses conventional flotation reagent systems such as sodium hexametaphosphate, it is difficult to fundamentally solve the influence of fine mud on the recovery of lithium mica. Therefore, it is only applicable to ores with low weathering degree, and the adaptability of ores with high weathering degree and large mud content is poor. Therefore, the patent is not very applicable to the comprehensive recovery of lithium-containing porcelain clay ores.

[0005] Based on this, in view of the special resource properties of lithium-containing kaolin ore, a mineral processing method with low lithium loss rate, high product added value, good sorting effect, high recovery index and strong adaptability has been developed, which is of great significance to improving the analysis efficiency of lithium mica and the comprehensive utilization level of this type of resources. Summary of the invention

[0006] The purpose of the present invention is to provide a stable, efficient, good separation effect, strong adaptability, high recovery index, high product added value, high comprehensive utilization rate of lithium-containing porcelain clay ore magnetic-flotation combined lithium extraction beneficiation method, aiming to solve the existing lithium-containing porcelain clay ore beneficiation technology existing in the large lithium loss, low lithium mica recovery index, lithium mica and gangue mineral separation effect is poor, the fine mud resource utilization is difficult and other problems.

[0007] The present invention is achieved by a method for extracting lithium from lithium-containing china clay ore by magnetic-flotation combination, comprising the following steps:

[0008] (1) grinding the lithium-containing china clay ore;

[0009] (2) The ground slurry is classified to obtain fine mud I and coarse sand;

[0010] (3) subjecting the fine mud I obtained in step (2) to weak magnetic separation to obtain fine mud II and magnetic product I; wherein the process conditions for the weak magnetic separation of fine mud I are: a magnetic field intensity of 0.6 to 0.8 T;

[0011] (4) subjecting the fine mud II obtained in step (3) to strong magnetic separation to obtain fine mud III and magnetic separation product II; wherein the process conditions for the strong magnetic separation of fine mud II are: a magnetic field strength of 1.3 to 1.7 T and a pulsation frequency of 50 to 100 rpm;

[0012] (5) subjecting the fine mud III obtained in step (4) to strong magnetic separation to obtain feldspar powder and magnetic product III; wherein the process conditions for the strong magnetic separation of the fine mud III are: a magnetic field strength of 1.5 to 1.8 T and a pulsation frequency of 30 to 70 rpm;

[0013] (6) combining the three magnetic products obtained in steps (3) to (5), namely, magnetic product I, magnetic product II, and magnetic product III, and concentrating them to obtain a mixed magnetic product with a higher concentration;

[0014] (7) combining the mixed magnetic product obtained in step (6) with the coarse sand obtained in step (2), and then adding clean water to adjust the slurry concentration to 30-40%;

[0015] (8) subjecting the slurry after adjusting the concentration in step (7) to rough separation of lithium mica to obtain lithium mica rough concentrate and flotation tailings I; wherein the rough separation process conditions of lithium mica are: firstly adding 100-400 g / t of dispersant YF3-2 for 3-5 min, and then adding 250-450 g / t of collector ZY-07 for 2-3 min;

[0016] (9) scavenging the flotation tailings I obtained in step (8) twice to obtain flotation tailings and two scavenged tailings, and the two scavenged tailings are returned to the previous layer in sequence; wherein the process conditions for scavenging the flotation tailings I twice are as follows: adding 50-150 g / t of dispersant YF3-2 to scavenging I, the operation time is 3-5 min, adding 50-100 g / t of collector ZY-07, the action time is 2-3 min, and adding 50-100 g / t of collector ZY-07 to scavenging II, the action time is 2-3 min;

[0017] (10) The lithium mica rough concentrate obtained in step (8) is beneficiated twice to obtain a lithium mica concentrate and two beneficiated intermediates, and the two beneficiated intermediates are returned to the previous operation in sequence; wherein the process conditions for beneficiating the lithium mica rough concentrate twice are as follows: adding 50-150 g / t of dispersant YF3-2 in beneficiation I and the operation time is 3-5 min, adding 30-100 g / t of dispersant YF3-2 in beneficiation II and the operation time is 3-5 min, and adding 5-20 g / t of collector ZY-07 and the action time is 2-3 min;

[0018] Preferably, in step (1), the grinding fineness is -0.074 mm and the content is 35-50%.

[0019] Preferably, in step (2), the classified particle size is 0.018 to 0.038 mm.

[0020] Preferably, in step (6), the concentration process conditions are as follows: the concentration of the concentrated slurry is 30-35%.

[0021] Preferably, the dispersant YF3-2 is obtained by mixing sodium hexametaphosphate, poly (sodium p-styrene sulfonate) and sodium methylene bisnaphthalene sulfonate in a mass ratio of 3:1:(1-2) and stirring the mixture evenly.

[0022] Preferably, the collector ZY-07 is obtained by mixing cotton oil, coconut amine, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride and styrenephosphonic acid in a mass ratio of 2:3:(1-2):1 and stirring the mixture evenly.

[0023] The present invention overcomes the shortcomings of the prior art and provides a method for extracting lithium from lithium-containing porcelain clay ore by magnetic-flotation combination. The specific steps are as follows:Figure 1 As shown, it has the following technical features:

[0024] (1) The present invention adopts a graded desludging method to reduce the influence of fine mud on the flotation of lithium mica. Based on the characteristics of lithium mica's flaky structure that is easily entrained and the isomorphism of iron and manganese elements that improves the specific magnetic susceptibility, the present invention creatively adopts weak magnetic and strong magnetic multi-field strengths and multi-medium combination to achieve step-by-step magnetic separation and recovery of fine lithium mica in fine mud, which not only solves the problem of high lithium loss rate in fine mud, but also reduces the content of impurities such as iron and titanium in fine mud, so that the whiteness of feldspar powder after lithium selection as a ceramic raw material can reach more than 45%, becoming a fine-grained ceramic raw material, realizing the comprehensive resource utilization of fine mud and increasing the added value of the product.

[0025] (2) The present invention combines the sorted magnetic product with the graded coarse sand to adjust the slurry to ensure the optimal concentration required for the flotation operation. YF3-2 is used as a dispersant to further solve the influence of fine gangue particles on flotation. The phosphonate and sulfonate in the dispersant can reduce the surface potential of the mineral and improve the dispersibility of the pulp. The components of poly (sodium p-styrene sulfonate) and sodium methylene bis naphthalene sulfonate selectively inhibit gangue minerals and complex to eliminate the interfering metal ions of the pulp. ZY-07 is used as a collector to selectively adsorb lithium mica minerals and enhance the collection capacity of fine lithium mica. Its main components, cotton oil and dimethyl octadecyl [3- (trimethoxysilyl) propyl] ammonium chloride, can be specifically adsorbed on the mineral surface, and other anionic collectors, styrene phosphonic acid, and cationic collectors, coconut oil amine, can achieve multi-layer adsorption through intermolecular association. The styrene phosphonic acid component reduces the viscosity of the pulp foam and reduces the entrainment of the foam to the gangue during the flotation process. The problems of poor selectivity and low collection capacity of the traditional lithium mica flotation reagent system are overcome, and the efficient sorting and recovery of lithium mica are achieved. The dispersant YF3-2 and collector ZY-07 used in the present invention are developed through a large number of reagent adsorption tests and flotation tests, and the reagent components and proportions thereof have not been disclosed and are not easily conceivable in the technical field.

[0026] (3) The present invention adopts the process flow of "graded desludging - fine mud magnetic separation - combined flotation of magnetic products and coarse sand" to sort and recover lithium mica, which improves the lithium mica recovery effect and product added value. This creative idea and process flow structure and complete set of technology as a whole are used in the field of mineral processing technology for extracting lithium from lithium-containing porcelain clay ores, which has not been disclosed and is not easy to think of. It is a new mineral processing method that is stable, efficient, highly adaptable, has good separation effect, high recovery index, and has a large product added value.

[0027] Compared with the prior art, the advantages of the present invention are:

[0028] ① The present invention solves the problem of high total lithium loss rate of fine mud caused by the great influence of fine mud on the separation of lepidolite, and improves the recovery effect of fine lepidolite.

[0029] ② The present invention solves the problem of fine mud resource utilization and increases the added value of lithium-containing porcelain clay ore dressing products.

[0030] ③ The present invention solves the problems of low recovery rate of lepidolite and poor separation effect from gangue minerals caused by low capture capacity and poor selectivity of traditional reagent systems, and improves the separation efficiency of lepidolite. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The present invention is a flowchart of the steps of a mineral processing method for magnetic-flotation combined lithium extraction from lithium-containing china clay ore. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0033] Example 1

[0034] 300g of sodium hexametaphosphate, 100g of poly (sodium p-styrene sulfonate) and 150g of sodium methylene bisnaphthalene sulfonate are taken as raw materials for mixing and preparation. The mixing and preparation process is carried out at normal temperature and pressure. A beaker is used as a container and a linkage stirrer is used for stirring (stirring time is 30min). No other auxiliary facilities and additives are required. After mixing evenly, dispersant YF3-2 is obtained.

[0035] 200g of cotton oil, 300g of coconut amine, 100g of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride and 100g of styrenephosphonic acid were mixed and prepared. The mixing process was carried out in a constant temperature water bath at 60°C and normal pressure. A beaker was used as a container and a linkage stirrer was used for stirring (stirring time was 30min). No other auxiliary facilities and additives were required. After mixing evenly, the collector ZY-07 was obtained.

[0036] Example 2

[0037] 300g of sodium hexametaphosphate, 100g of poly (sodium p-styrene sulfonate) and 200g of sodium methylene bisnaphthalene sulfonate are taken as raw materials for mixing and preparation. The mixing and preparation process is carried out at normal temperature and pressure. A beaker is used as a container and a linkage stirrer is used for stirring (stirring time is 30min). No other auxiliary facilities and additives are required. After mixing evenly, dispersant YF3-2 is obtained.

[0038] 200g of cotton oil, 300g of coconut amine, 160g of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride and 100g of styrenephosphonic acid were mixed and prepared. The mixing process was carried out in a constant temperature water bath at 60°C and normal pressure. A beaker was used as a container and a linkage stirrer was used for stirring (stirring time was 30min). No other auxiliary facilities and additives were required. After mixing evenly, the collector ZY-07 was obtained.

[0039] Example 3

[0040] The selected lithium-containing china clay ore contains 0.34% Li2O. The main mineral components in the ore are iron lithium mica (content 14.53%), quartz (content 36.28%), plagioclase (content 31.63%), and potassium feldspar (content 14.79%). Lithium is mainly present in the form of iron lithium mica, and a small amount is present in plagioclase, potassium feldspar and other aluminum silicate minerals. LA-ICP-MS analysis shows that the theoretical grade of iron lithium mica is low, only 2.26%, and the mineral embedding characteristics are complex, and there is a more significant weathering phenomenon. The dispersant YF3-2 and collector ZY-07 in Example 2 are used in the following steps. The lithium-containing china clay ore is sorted, and the sorting steps are:

[0041] (1) grinding the lithium-containing china clay ore; wherein the grinding fineness is -0.074 mm and the content accounts for 40%;

[0042] (2) The ground slurry is classified to obtain fine mud I and coarse sand; wherein the classification particle size is 0.031 mm;

[0043] (3) subjecting the fine mud I obtained in step (2) to weak magnetic separation to obtain fine mud II and magnetic product I; wherein the process conditions for the weak magnetic separation of fine mud I are: the magnetic field intensity is 0.8 T;

[0044] (4) subjecting the fine mud II obtained in step (3) to strong magnetic separation to obtain fine mud III and magnetic separation product II; wherein the process conditions for the strong magnetic separation of fine mud II are: strong magnetic intensity of 1.5 T and pulsation frequency of 80 rpm;

[0045] (5) subjecting the fine mud III obtained in step (4) to strong magnetic separation to obtain feldspar powder and magnetic product III; wherein the process conditions for the strong magnetic separation of the fine mud III are: a magnetic field intensity of 1.7 T and a pulsation frequency of 50 rpm;

[0046] (6) combining the three magnetic products obtained in steps (3) to (5), namely, magnetic product I, magnetic product II, and magnetic product III, and concentrating them to obtain a mixed magnetic product with a concentration of 30%;

[0047] (7) combining the mixed magnetic product obtained in step (6) with the coarse sand obtained in step (2), and then adding clean water to adjust the slurry concentration to 32%;

[0048] (8) subjecting the slurry after adjusting the concentration in step (7) to rough separation of lithium mica to obtain lithium mica rough concentrate and flotation tailings I; wherein the rough separation process conditions of lithium mica are: firstly adding 200 g / t of dispersant YF3-2 for 5 min, and then adding 350 g / t of collector ZY-07 for 3 min;

[0049] (9) The flotation tailings I obtained in step (8) are scavenged twice to obtain flotation tailings and two scavenged tailings, and the two scavenged tailings are returned to the previous layer in sequence; wherein the process conditions for scavenging the flotation tailings I twice are as follows: scavenging I adds 100 g / t of dispersant YF3-2, the operation time is 5 min, and then adds 70 g / t of collector ZY-07, the action time is 3 min, and scavenging II adds 50 g / t of collector ZY-07, the action time is 3 min;

[0050] (10) The lithium mica rough concentrate obtained in step (8) is beneficiated twice to obtain a lithium mica concentrate and two beneficiated intermediates, and the two beneficiated intermediates are returned to the previous operation in sequence; wherein the process conditions for beneficiating the lithium mica rough concentrate twice are: adding 100 g / t of dispersant YF3-2 in beneficiation I and the operation time is 3 min, adding 40 g / t of dispersant YF3-2 in beneficiation II and the operation time is 3 min, and then adding 15 g / t of collector ZY-07 and the action time is 3 min;

[0051] The feldspar powder yield obtained in this embodiment is 12.22%, the Fe2O3 content is reduced from 1.18% (fine mud I) to 0.42%, the whiteness is increased from 11.76% (fine mud I) to 50.23%, the Li2O loss rate in the feldspar powder is reduced from 16.88% (fine mud I) to 3.97%, the obtained lithium mica concentrate contains Li2O 2.23%, the Li2O recovery rate is 89.47%, the Li2O in the flotation tailings is only 0.03%, and the Li2O loss rate is 6.57%.

[0052] Example 4

[0053] The selected lithium-containing china clay ore contains 0.50% Li2O. The main mineral components in the ore are lithium white mica (content 15.16%), quartz (content 28.35%), and feldspar (content 54.53%). Lithium is mainly present in the form of lithium white mica, and a small amount is present in feldspar, spodumene and other aluminosilicate minerals. LA-ICP-MS analysis shows that the theoretical grade of lithium white mica is 3.14%, the mineral embedding characteristics are complex, and the degree of weathering is low. The dispersant YF3-2 and collector ZY-07 in Example 1 are used in the following steps. The lithium-containing china clay ore is sorted, and the sorting steps are as follows:

[0054] (1) grinding the raw ore of lithium-containing china clay; wherein the grinding fineness is -0.074 mm and the content accounts for 40%;

[0055] (2) The ground slurry is classified to obtain fine mud I and coarse sand; wherein the classification particle size is 0.025 mm;

[0056] (3) subjecting the fine mud I obtained in step (2) to weak magnetic separation to obtain fine mud II and magnetic product I; wherein the process conditions for the weak magnetic separation of fine mud I are: the magnetic field intensity is 0.8 T;

[0057] (4) subjecting the fine mud II obtained in step (3) to strong magnetic separation to obtain fine mud III and magnetic separation product II; wherein the process conditions for the strong magnetic separation of fine mud II are: strong magnetic intensity of 1.7 T and pulsation frequency of 100 rpm;

[0058] (5) subjecting the fine mud III obtained in step (4) to strong magnetic separation to obtain fine-grained ceramic raw materials and magnetic product III; wherein the process conditions for the strong magnetic separation of the fine mud III are: a magnetic field intensity of 1.8 T and a pulsation frequency of 50 rpm;

[0059] (6) combining the three magnetic products obtained in steps (3) to (5), namely, magnetic product I, magnetic product II, and magnetic product III, and concentrating them to obtain a mixed magnetic product with a concentration of 30%;

[0060] (7) combining the mixed magnetic product obtained in step (6) with the coarse sand obtained in step (2), and then adding clean water to adjust the slurry concentration to 35%;

[0061] (8) subjecting the slurry after adjusting the concentration in step (7) to rough separation of lithium mica to obtain lithium mica rough concentrate and flotation tailings I; wherein the rough separation process conditions of lithium mica are: firstly adding 200 g / t of dispersant YF3-2 for 5 min, and then adding 300 g / t of collector ZY-07 for 3 min;

[0062] (9) The flotation tailings I obtained in step (8) are scavenged twice to obtain flotation tailings and two scavenged tailings, and the two scavenged tailings are returned to the previous layer in sequence; wherein the process conditions for scavenging the flotation tailings I twice are as follows: scavenging I adds 100 g / t of dispersant YF3-2, the operation time is 5 min, and then adds 100 g / t of collector ZY-07, the action time is 3 min, and scavenging II adds 70 g / t of collector ZY-07, the action time is 3 min;

[0063] (10) The lithium mica rough concentrate obtained in step (8) is beneficiated twice to obtain a lithium mica concentrate and two beneficiated intermediates, and the two beneficiated intermediates are returned to the previous operation in sequence; wherein the process conditions for beneficiating the lithium rough concentrate twice are: adding 150 g / t of dispersant YF3-2 in beneficiation I and the operation time is 3 min, adding 50 g / t of dispersant YF3-2 in beneficiation II and the operation time is 3 min, and then adding 10 g / t of collector ZY-07 and the action time is 3 min;

[0064] The yield of the feldspar powder raw material obtained in this embodiment is 15.63%, the Fe2O3 content is reduced from 1.06% (fine mud I) to 0.45%, the whiteness is increased from 14.34% (fine mud I) to 48.75%, and the Li2O loss rate in the feldspar powder raw material is reduced from 15.39% (fine mud I) to 6.35%. The obtained lithium mica concentrate contains 3.07% Li2O and the Li2O recovery rate is 87.93%. The Li2O in the flotation tailings is only 0.04%, and the Li2O loss rate is 5.71%.

[0065] Example 5

[0066] The selected lithium-containing china clay ore contains 0.45% Li2O. The main mineral components in the ore are iron lithium mica (content 10.79%), quartz (content 35.68%), and feldspar (content 47.29%). Lithium is mainly present in the form of iron lithium mica. LA-ICP-MS analysis shows that the theoretical grade of iron lithium mica is 3.78%. The mineral embedding characteristics are complex and the weathering phenomenon is more significant. The dispersant YF3-2 and collector ZY-07 in Example 2 are used in the following steps. The lithium-containing china clay ore is sorted, and the sorting steps are as follows:

[0067] (1) grinding the lithium-containing china clay ore; wherein the grinding fineness is -0.074 mm and the content is 45%;

[0068] (2) The ground slurry is classified to obtain fine mud I and coarse sand; wherein the classification particle size is 0.031 mm;

[0069] (3) subjecting the fine mud I obtained in step (2) to weak magnetic separation to obtain fine mud II and magnetic product I; wherein the process conditions for the weak magnetic separation of fine mud I are: the magnetic field intensity is 0.7 T;

[0070] (4) subjecting the fine mud II obtained in step (3) to strong magnetic separation to obtain fine mud III and magnetic separation product II; wherein the process conditions for the strong magnetic separation of fine mud II are: magnetic intensity of 1.6 T and pulsation frequency of 100 rpm;

[0071] (5) subjecting the fine mud III obtained in step (4) to strong magnetic separation to obtain fine-grained ceramic raw materials and magnetic product III; wherein the process conditions for the strong magnetic separation of the fine mud III are: a magnetic field intensity of 1.8 T and a pulsation frequency of 50 rpm;

[0072] (6) combining the three magnetic products obtained in steps (3) to (5), namely, magnetic product I, magnetic product II, and magnetic product III, and concentrating them to obtain a mixed magnetic product with a concentration of 30%;

[0073] (7) combining the mixed magnetic product obtained in step (6) with the coarse sand obtained in step (2), and then adding clean water to adjust the slurry concentration to 30%;

[0074] (8) subjecting the slurry after adjusting the concentration in step (7) to rough separation of lithium mica to obtain lithium mica rough concentrate and flotation tailings I; wherein the rough separation process conditions of lithium mica are: firstly adding 200 g / t of dispersant YF3-2 for 5 min, and then adding 280 g / t of collector ZY-07 for 3 min;

[0075] (9) The flotation tailings I obtained in step (8) are scavenged twice to obtain flotation tailings and two scavenged tailings, and the two scavenged tailings are returned to the previous layer in sequence; wherein the process conditions for scavenging the flotation tailings I twice are as follows: adding 100 g / t of dispersant YF3-2 to scavenging I for 5 min, and then adding 80 g / t of collector ZY-07 for 3 min, and adding 40 g / t of collector ZY-07 for 3 min to scavenging II;

[0076] (10) The lithium mica rough concentrate obtained in step (8) is beneficiated twice to obtain a lithium mica concentrate and two beneficiated intermediates, and the two beneficiated intermediates are returned to the previous operation in sequence; wherein the process conditions for beneficiating the lithium mica rough concentrate twice are: adding 100 g / t of dispersant YF3-2 in beneficiation I and the operation time is 3 min, adding 40 g / t of dispersant YF3-2 in beneficiation II and the operation time is 3 min, and then adding 8 g / t of collector ZY-07 and the action time is 3 min;

[0077] The feldspar powder yield obtained in this embodiment is 16.17%, the Fe2O3 content is reduced from 1.47% (fine mud I) to 0.37%, the whiteness is increased from 12.59% (fine mud I) to 55.39%, the Li2O loss rate in the feldspar powder is reduced from 16.35% (fine mud I) to 6.15%, the obtained lithium mica concentrate contains 3.71% Li2O, the Li2O recovery rate is 88.59%, the Li2O in the flotation tailings is only 0.03%, and the Li2O loss rate is 5.26%.

[0078] Comparative Example

[0079] The selected raw ore contains 0.65% Li2O. The main useful minerals in the ore are lithium mica, and the gangue minerals are mainly quartz and feldspar, containing a small amount of montmorillonite. The lithium mica concentrate obtained by the existing desludging flotation process (reference: "Flotation Experimental Research on a Low-Grade Lithium Mica Mine in Jiangxi", Feng Liqin, Non-Metallic Minerals, Vol. 42, No. 1, pp. 60-62, January 2019) contains 3.09% Li2O and a Li2O recovery rate of 70.96%. The removed fine mud is abandoned and not treated, the fine mud yield is 18.39%, and the Li2O loss rate in the fine mud is 12.34%.

[0080] The present invention provides a method for the beneficiation of lithium-containing china clay ore by magnetic-flotation combined extraction of lithium, adopts the process flow of "graded desludging-fine mud magnetic separation-magnetic product and graded coarse sand combined flotation" to carry out the beneficiation and recovery of lithium mica, the magnetic separation operation adopts weak magnetic-strong magnetic step-by-step recovery of fine lithium mica, the flotation operation adds YF3-2 as a dispersant and ZY-07 as a collector, and the flotation separation of lithium mica and gangue is carried out, while improving the separation effect of lithium mica, high-whiteness feldspar powder is obtained, and efficient comprehensive recovery of lithium-containing china clay ore is realized. The present invention is a new method for beneficiation of lithium-containing china clay ore that is stable, efficient, has strong adaptability, good separation effect, high recovery index, and high product added value, and is suitable for promotion and application.

[0081] In the above embodiments, the contents not described in detail in this specification are known prior art to professionals in the field. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements 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 extracting lithium from lithium-containing china clay ore by magnetic-flotation combination, characterized in that: The following steps are involved: (1) Grinding the lithium-containing china clay ore; (2) The ground slurry is classified to obtain fine mud I and coarse sand; (3) subjecting the fine mud I obtained in step (2) to weak magnetic separation to obtain fine mud II and magnetic product I; wherein the process conditions for the weak magnetic separation of fine mud I are: a magnetic field intensity of 0.6 to 0.8 T; (4) subjecting the fine mud II obtained in step (3) to strong magnetic separation to obtain fine mud III and magnetic separation product II; wherein the process conditions for the strong magnetic separation of fine mud II are: a magnetic field intensity of 1.3 to 1.7 T and a pulsation frequency of 50 to 100 rpm; (5) subjecting the fine mud III obtained in step (4) to strong magnetic separation to obtain feldspar powder and magnetic product III; wherein the process conditions for the strong magnetic separation of the fine mud III are: a magnetic field strength of 1.5 to 1.8 T and a pulsation frequency of 30 to 70 rpm; (6) The three magnetic products, namely, magnetic product I, magnetic product II, and magnetic product III, obtained in step (5) are combined and concentrated to obtain a mixed magnetic product with a higher concentration; (7) combining the mixed magnetic product obtained in step (6) with the coarse sand obtained in step (2), and then adding clean water to adjust the slurry concentration to 30-40%; (8) The slurry after the concentration adjustment in step (7) is subjected to rough separation of lithium mica to obtain a lithium mica rough concentrate and flotation tailings I; wherein the rough separation process conditions of the lithium mica are: firstly adding 100 to 400 g / t of dispersant YF3-2 for 3 to 5 min, and then adding 250 to 450 g / t of collector ZY-07 for 2 to 3 min; (9) scavenging the flotation tailings I obtained in step (8) twice to obtain flotation tailings and two scavenged tailings, and the two scavenged tailings are returned to the previous operation in sequence; The process conditions for the two scavenging of flotation tailings I are as follows: adding dispersant YF3-2 50-150g / t, the operation time is 3-5min, adding collector ZY-07 50-100g / t, the action time is 2-3min, adding collector ZY-07 50-100g / t, the action time is 2-3min in scavenging I, and adding collector ZY-07 50-100g / t, the action time is 2-3min in scavenging II. (10) The lepidolite rough concentrate obtained in step (8) is beneficiated twice to obtain a lepidolite concentrate and two beneficiated middlings, and the two beneficiated middlings are sequentially returned to the previous operation layer; The process conditions for the two times of selection of lithium mica rough concentrate are as follows: adding dispersant YF3-2 50-150g / t in selection I and the operation time is 3-5min, adding dispersant YF3-2 30-100g / t in selection II and the operation time is 3-5min, adding collector ZY-07 5-20g / t and the action time is 2-3min; The dispersant YF3-2 is obtained by mixing sodium hexametaphosphate, poly (sodium p-styrene sulfonate), and sodium methylene bis-naphthalene sulfonate in a mass ratio of 3:1:(1-2) and stirring evenly; The collector ZY-07 is obtained by mixing cotton oil, coconut amine, dimethyl octadecyl [3-(trimethoxysilyl)propyl] ammonium chloride and styrene phosphonic acid in a mass ratio of 2:3:(1-2):1 and stirring the mixture evenly.

2. The method for extracting lithium from lithium-containing china clay ore by magnetic-flotation combination as claimed in claim 1, characterized in that: In step (1), the fineness of the ground lithium-containing china clay ore is -0.074 mm and the content is 35-50%.

3. The method for extracting lithium from lithium-containing china clay ore by magnetic-flotation combination as claimed in claim 1, characterized in that: In step (2), the classification particle size is 0.018-0.038 mm.

4. The method for extracting lithium from lithium-containing china clay ore by magnetic-flotation combination according to claim 1, characterized in that: In step (6), the concentration process conditions are as follows: the concentration of the mixed magnetic product after concentration is 30-35%.

Images