Pre-selection method and system for iron lepidolite before grinding

Abstract

The invention relates to a pre-concentration method and system for iron lepidolite before grinding. The system comprises a high-pressure roller grinding device, a first-section screening device, a strong magnetic pre-concentration roughing device, a first-section pre-concentration strong magnetic scavenging device, a second-section pre-concentration strong magnetic scavenging device, a grading device and a strong magnetic fine particle recycling device. Compared with the prior art, the method has the advantages that fine crushing operation is replaced by closed-loop operation of the high-pressure roller mill and the micro-powder sieve, and compared with traditional fine crushing-ore grinding-sieving operation, the technological process is simplified, the granularity of undersize products is strictly controlled, and the over-crushing phenomenon in the conventional process is avoided. Secondly, the processes of pre-selection and roughing by a magnetic separator, two times of scavenging and strong magnetic fine particle recovery are adopted, gangue minerals are removed, meanwhile, machine-made sand products can be obtained, qualified tailings are prevented from entering the follow-up grading operation, and the utilization rate of mineral resources is increased; the ore amount of the subsequent grinding separation operation is reduced, and the pre-selected concentrate with the high LiO2 grade is supplied to the subsequent flotation operation; and meanwhile, the loss of fine ore is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of ore dressing technology, and in particular relates to a pre-grinding method and system for pre-selecting lithium iron mica. Background Art

[0002] As an important strategic new energy mineral, lithium plays an important role in many fields such as batteries, nuclear energy and military industry. Improving the comprehensive recovery level of lithium minerals and rationally developing and utilizing lithium-containing resources are of great significance to alleviating the contradiction between supply and demand of lithium consumption in my country and promoting the efficient recovery of rare metal mineral resources.

[0003] Iron lithium mica has a complex composition and many associated components. Although it is an aluminum silicate mineral like lepidolite, its lithium content is lower than that of lepidolite (2%-4%), and its iron and fluorine content is high (about 12.78% Fe, about 6.52% F), and it has weak magnetism. Nowadays, the recovery of iron lithium mica mainly includes lithium extraction from brine and lithium extraction from ore. Lithium extraction from ore mainly relies on combined processes for separation. In recent years, the industry has carried out detailed experimental research on the recovery of iron lithium mica. The recovery methods such as non-de-sludge flotation of iron lithium mica (application number 202010130105.0), magnetic separation recovery method of fine-grained lithium ore (202311588930.9), and gravity-magnetic-flotation combined process (201510380467.8) have been proposed. However, these methods mainly recover the iron lithium mica after grinding and fully dissociating it, and the pre-grinding pretreatment of iron lithium mica has not been fully studied.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The purpose of the present invention is to provide a pre-grinding pre-selection method and system for lithium iron ore mica, which can discard part of the coarse-grained gangue minerals in advance, improve the LiO2 grade in the subsequent separation process, and at the same time, carry out strong magnetic fine particle recovery on the pre-selected tailings, further reduce the loss of fine-grained ore, and increase the machine-made sand product. The present invention is a pre-treatment system that can optimize the lithium iron ore separation process, has good separation effect, reduces the grinding amount and flotation agent consumption, has a small metal loss, and is clean and environmentally friendly.

[0006] To achieve one of the above purposes, the present invention provides the following technical solutions:

[0007] A method for pre-selecting lithium iron mica before grinding, comprising the following steps:

[0008] S100, subjecting the raw ore to a high pressure roller mill operation, and subjecting the products after roller milling to a screening operation, respectively obtaining a section of oversize product and a section of undersize product, and the section of oversize product returns to the high pressure roller mill to form a closed circuit;

[0009] S200, feeding the first stage underscreen product into a strong magnetic separator for strong magnetic pre-selection and roughing operation to obtain roughing concentrate and roughing tailings respectively;

[0010] S300, subjecting the rougher tailings to a pre-selection strong magnetic sweeping operation to obtain a pre-selection strong magnetic sweeping concentrate and a pre-selection strong magnetic sweeping tailings;

[0011] S400, subjecting the first-stage pre-selection strong magnetic sweeping tailings to a second-stage pre-selection strong magnetic sweeping operation to obtain a second-stage pre-selection strong magnetic sweeping concentrate and a second-stage pre-selection strong magnetic sweeping tailings;

[0012] S500, classifying the second-stage pre-selected strong magnetic sweeping tailings to obtain the grading screen-surface product and the grading screen-underface product respectively;

[0013] S600, recover the high-magnetic fine particles of the products under the grading screen to obtain high-magnetic fine particle concentrate and high-magnetic fine particle tailings respectively.

[0014] Preferably, in step S100:

[0015] The particle size of the original ore is 50-0mm, the particle size of the product above the first screen is 50-3mm, and the particle size of the product under the first screen is 3-0mm.

[0016] Preferably, in step S200:

[0017] The magnetic field strength in the strong magnetic pre-selection and roughing operation is 1.5T.

[0018] Preferably, in step S300:

[0019] The magnetic field strength in the first stage of pre-selection strong magnetic sweeping operation is 1.7T.

[0020] Preferably, in step S400:

[0021] The magnetic field strength in the second-stage pre-selection strong magnetic sweeping operation is 1.7T.

[0022] Preferably, in step S500:

[0023] The particle size of the product on the grading screen is 3-0.5mm, and the particle size of the product under the grading screen is 0.5-0mm.

[0024] Preferably, in step S600:

[0025] The magnetic field strength for strong magnetic fine particle recovery is 1.7T.

[0026] To achieve the second of the above objectives, the present invention provides the following technical solutions:

[0027] A pre-grinding pre-selection system for lithium iron mica comprises a high-pressure roller mill, a first-stage screening device, a strong magnetic pre-selection roughing device, a first-stage pre-selection strong magnetic sweeping device, a second-stage pre-selection strong magnetic sweeping device, a grading device, and a strong magnetic fine particle recovery device.

[0028] Compared with the prior art, the pre-grinding pre-selection method and system of lithium iron mica proposed in the present invention has the following beneficial effects:

[0029] 1. The present invention adopts a closed-circuit operation of a high-pressure roller mill and a micro powder screen to replace the fine crushing operation. Compared with the traditional fine crushing-grinding-screening operation, it simplifies the process flow, strictly controls the particle size of the product under the screen, and avoids the "over-crushing" phenomenon in the conventional process.

[0030] 2. The present invention adopts a magnetic separator pre-selection roughing, two sweeping selections, and strong magnetic fine particle recovery process. The gangue minerals can be removed and the machine-made sand product can be obtained at the same time, which not only avoids the qualified tailings from entering the subsequent separation operation, but also increases the utilization rate of mineral resources; reduces the amount of ore in the subsequent grinding operation, so that the pre-selected concentrate with a higher LiO2 grade can be used for the subsequent flotation operation; and at the same time reduces the loss of fine-grained ore.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 The present invention is a process flow chart of a method for pre-grinding pre-selection of lithium iron mica proposed in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0035] like Figure 1 As shown, the embodiment of the present invention provides a method for pre-grinding iron lithium mica, which specifically includes the following steps:

[0036] 1. The raw ore (50-0mm) is subjected to high pressure roller grinding. The products after roller grinding are screened, and the products on the screen (50-0mm) are returned to the high pressure roller grinding to form a closed circuit;

[0037] 2. The undersize product (3-0mm) is fed into the strong magnetic separator for strong magnetic pre-selection and roughing. The tailings after roughing are subjected to the first-stage pre-selection and strong magnetic sweeping operation. The first-stage pre-selection and strong magnetic sweeping tailings are subjected to the second-stage pre-selection and strong magnetic sweeping operation.

[0038] 3. The second stage pre-selection strong magnetic sweeping tailings are used for pre-selection tailings classification. The screened products (3-0.5mm) are used as tailings or machine-made sand, and the screened products (0.5-0mm) are used for strong magnetic fine particle recovery.

[0039] 4. The pre-selected rougher concentrate, pre-selected strong magnetic scavenging concentrate 1, pre-selected strong magnetic scavenging concentrate 2 and strong magnetic fine-grained concentrate are combined as pre-selected concentrate for subsequent separation operations.

[0040] In the pre-grinding pre-selection method of lithium iron mica provided in the above embodiment of the present invention, the magnetic field strength of the rough pre-selection is 1.5T, and the magnetic field strength of the first-stage pre-selection strong magnetic sweeping, the second-stage pre-selection strong magnetic sweeping, and the strong magnetic fine particle recovery is 1.7T.

[0041] In the present invention, since the high-pressure roller mill and micro-powder screen closed-circuit operation are used to replace the fine crushing operation, compared with the traditional fine crushing-grinding operation-screening operation, the process flow is simplified, the particle size of the product under the screen is strictly controlled, and the "over-crushing" phenomenon in the conventional process is avoided. Secondly, the magnetic separator is used for pre-selection and roughing, two-time sweeping and strong magnetic fine particle recovery process, and the machine-made sand product can be obtained while removing the gangue minerals, which not only avoids the qualified tailings from entering the subsequent selection operation, but also increases the utilization rate of mineral resources; reduces the amount of ore in the subsequent grinding operation, so that the pre-selected concentrate with a higher LiO2 grade can be used for the subsequent flotation operation; and reduces the loss of fine ore.

[0042] The embodiment of the present invention provides a pre-grinding pre-selection system for lithium iron mica, including a high-pressure roller mill device, a first-stage screening device, a strong magnetic pre-selection roughing device, a first-stage pre-selection strong magnetic sweeping device, a second-stage pre-selection strong magnetic sweeping device, a grading device, and a strong magnetic fine particle recovery device. The high-pressure roller mill device performs a high-pressure roller mill operation, the first-stage screening device performs a first-stage screening operation, the strong magnetic pre-selection roughing device performs a strong magnetic pre-selection roughing operation, the first-stage pre-selection strong magnetic sweeping device performs a first-stage pre-selection strong magnetic sweeping operation, the second-stage pre-selection strong magnetic sweeping device performs a second-stage pre-selection strong magnetic sweeping operation, the grading device performs a pre-selection tailings grading operation, and the strong magnetic fine particle recovery device performs a strong magnetic fine particle recovery operation.

[0043] The invention discloses a pre-grinding pre-selection system for lithium iron ore mica, which can discard part of the coarse-grained gangue minerals in advance, improve the LiO2 grade in the subsequent selection process, and simultaneously carry out strong magnetic fine particle recovery on the pre-selected tailings, further reducing the loss of fine-grained ore. The invention is a pre-treatment system which can optimize the lithium iron ore selection process, has good selection effect, reduces the grinding amount and flotation agent consumption, has a small metal loss, and is clean and environmentally friendly.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention. It should be noted that similar numbers and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

Claims

1. A method for pre-selection of lithium iron mica before grinding, characterized in that: The method comprises the following steps: S100, subjecting the raw ore to a high pressure roller mill operation, and subjecting the products after roller milling to a screening operation, respectively obtaining a section of oversize product and a section of undersize product, and the section of oversize product returns to the high pressure roller mill to form a closed circuit; S200, feeding the first stage underscreen product into a strong magnetic separator for strong magnetic pre-selection and roughing operation to obtain roughing concentrate and roughing tailings respectively; S300, subjecting the rougher tailings to a pre-selection strong magnetic sweeping operation to obtain a pre-selection strong magnetic sweeping concentrate and a pre-selection strong magnetic sweeping tailings; S400, subjecting the first-stage pre-selection strong magnetic sweeping tailings to a second-stage pre-selection strong magnetic sweeping operation to obtain a second-stage pre-selection strong magnetic sweeping concentrate and a second-stage pre-selection strong magnetic sweeping tailings; S500, classifying the second-stage pre-selected strong magnetic sweeping tailings to obtain the grading screen-surface product and the grading screen-underface product respectively; S600, recover the high-magnetic fine particles of the products under the grading screen to obtain high-magnetic fine particle concentrate and high-magnetic fine particle tailings respectively.

2. The method for pre-grinding iron lithium mica according to claim 1, characterized in that: In step S100: The particle size of the original ore is 50-0mm, the particle size of the product above the first screen is 50-3mm, and the particle size of the product under the first screen is 3-0mm.

3. The method for pre-grinding iron lithium mica according to claim 1, characterized in that: In step S200: The magnetic field strength in the strong magnetic pre-selection and roughing operation is 1.5T.

4. The method for pre-grinding iron lithium mica according to claim 1, characterized in that: In step S300: The magnetic field strength in the first stage of pre-selection strong magnetic sweeping operation is 1.7T.

5. The method for pre-grinding iron lithium mica according to claim 1, characterized in that: In step S400: The magnetic field strength in the second-stage pre-selection strong magnetic sweeping operation is 1.7T.

6. The method for pre-grinding iron lithium mica according to claim 1, characterized in that: In step S500: The particle size of the product on the grading screen is 3-0.5mm, and the particle size of the product under the grading screen is 0.5-0mm.

7. The method for pre-grinding iron lithium mica according to claim 1, characterized in that: In step S600: The magnetic field strength for strong magnetic fine particle recovery is 1.7T.

8. A pre-grinding system for lithium iron mica, characterized in that: It includes a high-pressure roller grinding device, a first-stage screening device, a strong magnetic pre-selection roughing device, a first-stage pre-selection strong magnetic sweeping device, a second-stage pre-selection strong magnetic sweeping device, a grading device, and a strong magnetic fine particle recovery device.

Images