A beneficiation method for selecting iron concentrate from -1 mm tailings after comprehensive utilization of broken dust removal and recovery of ore pulp and dry throwing waste rock

Abstract

The present application belongs to the technical field of mineral processing, and mainly relates to a mineral processing method for breaking, dust removal and recovery of ore pulp and breaking, dry throwing and comprehensive utilization of waste stone to select iron concentrate from -1 mm tailings, mainly adopting the following steps: once screening-fine crushing of broken dry throwing waste stone; sand making-second screening; wheel sand washing-cyclone classification; broken dust removal and recovery of ore pulp; grinding and classification of broken dust removal and recovery of ore pulp and -1 mm tailings in the step (3)-weak magnetic separation. The method of the present application is a mineral processing method for further recovery of magnetite from -1 mm tailings generated after breaking, dust removal and recovery of ore pulp and breaking, dry throwing and comprehensive utilization of waste stone, which increases the concentrate yield benefit, reduces the discharge of fine particle grade tailings, and brings the purpose of cost reduction and benefit increase to enterprises.

Description

Technical Field

[0001] This invention belongs to the field of mineral processing technology, and mainly relates to a mineral processing method for extracting iron concentrate from fine-grained tailings generated after the comprehensive utilization of crushed and dust-recovered slurry and crushed dry-discharged waste rock. Specifically, it is a mineral processing method for extracting iron concentrate from -1mm tailings after the comprehensive utilization of crushed and dust-recovered slurry and crushed dry-discharged waste rock. Background Technology

[0002] The common crushing process for magnetite is a three-stage closed-circuit dry polishing process with screening. Dry polishing can improve the grade of the raw ore entering the mill, which is of great significance for reducing grinding production costs. Many mines adopt a direct sales model or further process the waste rock after crushing and dry polishing into various sizes of stone for sale. However, with the further processing of waste rock, the magnetic iron in the fine-grained tailings has basically reached a state of liberation and is not fully recovered. It is directly sent to the tailings filling process, resulting in the waste of useful resources. This also means that the slurry absorbed by the entire crushing and dust removal system is not fully recovered of its useful components and is directly sent to the tailings filling process, resulting in resource waste.

[0003] Existing technologies include “CN103406197B - Process for separating iron concentrate from lean magnetite tailings” and “CN107309080A - A method for comprehensive development and utilization of ultra-low grade primary magnetite”, but they fail to recover magnetite contained in the slurry produced by dust removal operations during the crushing process of the ore and the fine tailings produced after the comprehensive utilization of waste rock.

[0004] Therefore, how to maximize corporate benefits while comprehensively utilizing crushed and dry-disposaled waste rock, and simultaneously recovering low-grade magnetite contained in fine-grained tailings and magnetite from the slurry recovered by the crushing and dust removal system, is a pressing technical problem that needs to be solved. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned problems in the existing technology by providing a mineral processing method for extracting iron concentrate from the -1mm tailings after the comprehensive utilization of crushed and dust-removed slurry and crushed dry-disposal waste rock. This method aims to improve the comprehensive utilization of waste rock while simultaneously recovering magnetite from the fine-grained tailings and the crushed and dust-removed slurry, thereby increasing output value and benefits.

[0006] To achieve the above-mentioned objectives of this invention, the technical solution adopted is: a mineral processing method for extracting iron concentrate from -1mm tailings after comprehensive utilization of crushed and dust-recovered slurry and crushed dry-disposal waste rock, mainly employing the following steps:

[0007] (1) Crushing dry-disposal waste rock and screening it once for fine crushing;

[0008] The crushed dry waste rock undergoes a primary screening process using a double-layer screen. The material oversized by the upper screen enters the fine crusher for further crushing, and the crushed material is returned to the primary screening process. The material oversized by the lower screen is sold directly as stone, while the material undersized by the lower screen enters the sand making machine.

[0009] (2) Sand making - secondary screening;

[0010] In step (1), the material under the lower screen enters the sand making machine for stone shaping, and the shaped material enters the secondary screening.

[0011] The secondary screening uses a double-layer screen. The material overseen by the upper screen is sold directly as stone material II, and the material overseen by the lower screen is sold directly as stone material III. The material underseen by the lower screen enters the wheel-type sand washing machine.

[0012] (3) Wheel-type sand washing-cyclone grading

[0013] The material undersized from the lower screen of the secondary screening in step (2) enters the wheel sand washing machine for sand retrieval, and the retrieval sand enters the linear dewatering screen.

[0014] The material over the linear dewatering screen is sold as stone material; the material under the linear dewatering screen and the overflow from the sand washing machine enter the hydrocyclone for grading, the graded sand enters the linear dewatering screen, and the graded overflow is the -1mm tailings after comprehensive utilization of crushed dry waste stone.

[0015] (4) Crushing and dust removal recovery of slurry

[0016] The slurry recovered from crushing and dust removal refers to the slurry produced by mixing water with dust generated during the medium crushing, fine crushing, screening, and dry blasting operations of ore in the crushing process after it has been recovered by a dust removal device.

[0017] (5) The crushed and dust-recovered slurry and the 1mm tailings from step (3) are subjected to grinding, classification and weak magnetic separation.

[0018] The crushed and dust-recovered slurry and the tailings from step (3) -1mm first enter the pump pool, and then are pumped to the second-stage high-frequency fine screen in the magnetic separation zone for classification. The product on the screen enters the concentration magnetic separation, and the concentrated magnetic separation tailings enter the subsequent tailings disposal operation. The concentrated magnetic separation concentrate enters the second-stage grinding, and the slurry after the second-stage grinding enters the second-stage high-frequency fine screen for screening, forming a closed-loop circulation.

[0019] The screened products undergo secondary and tertiary weak magnetic separation in the magnetic separation area. The tertiary weak magnetic separation concentrate yields qualified iron concentrate. The tailings from the secondary and tertiary weak magnetic separations, as well as the concentrated magnetic separation tailings from step (5), are then processed in subsequent tailings disposal operations.

[0020] As an improved technical solution of this application, the primary screening adopts a circular vibrating screen, with the upper screen mesh size being 28*28mm and the lower screen mesh size being 18*18mm.

[0021] As an improved technical solution of this application, the sand making machine adopts the VSI7100 shaping crusher.

[0022] As an improved technical solution of this application, the secondary screening adopts a circular vibrating screen; the screen mesh diameter of the upper screen is 15*15mm, and the screen mesh diameter of the lower screen is 5*5mm.

[0023] As an improved technical solution of this application, the wheel-type sand washing machine is the Weihai Haiwang sand washing machine with model number XS2615.

[0024] As an improved technical solution of this application, the screen aperture of the linear dewatering screen is 0.3mm, and the hydrocyclone is a Neptune hydrocyclone, model FX350.

[0025] As an improved technical solution in this application, the aperture of the two-stage high-frequency fine screen is 0.1 mm.

[0026] As an improved technical solution of this application, the magnetic induction intensity of the secondary weak magnetic separation is controlled at 0.18-0.20 Tesla, the magnetic induction intensity of the tertiary weak magnetic separation is controlled at 0.16-0.18 Tesla, and the magnetic induction intensity of the concentrated magnetic separation is controlled at 0.30-0.35 Tesla.

[0027] Compared with existing technologies, the present invention provides a mineral processing method for the comprehensive utilization of crushed dry-discarded waste rock and simultaneous recovery of magnetite, which has the following advantages:

[0028] (1) After the dry-discarded waste rock is processed into four kinds of stone products for sale, the output value of waste rock is increased. The magnetic iron in the -1mm fine-grained tailings enters the ore magnetic separation process, and the resources are effectively recovered.

[0029] (2) The slurry recovered from crushing and dust removal enters the magnetic separation process for separation, and the resources are effectively recovered.

[0030] (3) Make full use of the magnetic separation process of ore, and without adding new equipment or production lines, fully recover the magnetic iron in the -1mm tailings and crushed dust removal slurry after comprehensive utilization of waste rock, thereby increasing output value and benefits.

[0031] In summary, this application makes full use of the combination of "crushed dry waste rock and crushed dust-recovered slurry". These two minerals have similar particle size composition and can be mixed and then fed into the existing ore grinding and beneficiation process without increasing the existing ore grinding and beneficiation process, thereby achieving the goal of reducing costs and increasing efficiency. Attached Figure Description

[0032] Figure 1 This is a flow chart of a mineral processing technology for extracting iron concentrate from -1mm tailings after comprehensive utilization of crushed and dust-removed slurry and crushed dry-disposal waste rock, according to the present invention. Detailed Implementation

[0033] To describe the present invention, the following detailed description, in conjunction with the accompanying drawings and embodiments, provides a method for beneficiating iron concentrate from -1mm tailings after comprehensive utilization of crushed and dust-recovered slurry and crushed dry-disposal waste rock.

[0034] A mineral processing method for extracting iron concentrate from -1mm tailings after comprehensive utilization of crushed and dust-recovered slurry and crushed dry-discharged waste rock, applicable to dry-discharged waste rock with an iron content between 7% and 10%, an MFE content between 0.5% and 3%, and a particle size between 10mm and 50mm, comprises the following steps:

[0035] (1) Crushing dry-disposal waste rock and screening it once for fine crushing;

[0036] The crushed dry waste rock undergoes a primary screening process using a double-layer screen. The material oversized by the upper screen enters the fine crusher for further crushing, and the crushed material is returned to the primary screening process. The material oversized by the lower screen is sold directly as aggregate, while the material undersized by the lower screen enters the sand making machine.

[0037] The purpose of this process is to obtain stone products through a single screening operation, and to form a closed loop by further screening of unqualified products after fine crushing.

[0038] The primary screening uses a circular vibrating screen, with the upper screen having a mesh size of 28*28mm and the lower screen having a mesh size of 18*18mm. The purpose of this size selection is to obtain stone with a qualified particle size.

[0039] (2) Sand making - secondary screening;

[0040] In step (1), the material under the lower screen enters the sand making machine for stone shaping, and the shaped material enters the secondary screening.

[0041] The secondary screening also uses a double-layer screen. The material overseen by the upper screen is sold directly as stone material II, and the material overseen by the lower screen is sold directly as stone material III. The material underseen by the lower screen enters the wheel-type sand washing machine.

[0042] The purpose of this process is to obtain stone material II and stone material III products through shaping and secondary screening, with the remaining products entering the next process.

[0043] The sand making machine used is a VSI7100 shaping crusher. This model is specifically chosen to refine the appearance of the second and third aggregate products, meeting sales requirements.

[0044] (3) Wheel-type sand washing-cyclone grading;

[0045] In step (2), the material under the lower screen of the secondary screening first enters the wheel sand washing machine for sand retrieval. The retrieval sand enters the linear dewatering screen, and the material on the dewatering screen is sold as stone material. The material under the dewatering screen and the overflow of the sand washing machine enter the hydrocyclone for grading. The graded sediment enters the linear dewatering screen, and the graded overflow is the -1mm tailings after comprehensive utilization of crushed dry waste rock.

[0046] The purpose of this process is to obtain the fourth product of the stone through sand washing and grading operations.

[0047] The secondary screening uses a circular vibrating screen; the upper screen has a mesh size of 15*15mm, and the lower screen has a mesh size of 5*5mm. The purpose of the dimensional constraints is to obtain stone material two and stone material three with qualified particle sizes.

[0048] The wheel-type sand washing machine used is the Weihai Haiwang sand washing machine, model XS2615. The purpose of specifying the model is to meet the grading requirements before obtaining the four-stage stone product.

[0049] The linear dewatering screen has a mesh size of 0.3mm, and the hydrocyclone used is a Neptune FX350 hydrocyclone. The purpose of the dimensional constraints is to obtain stone particles of the acceptable size.

[0050] (4) Crushed and dust-recovered slurry;

[0051] The slurry recovered from crushing and dust removal refers to the slurry produced after the dust generated during the medium crushing, fine crushing, screening, and dry blasting operations of the ore is recovered by a dust removal device and mixed with water. The ratio of water to dust in the slurry is determined by the dust removal effect, and the solid content is about 5%-10% (by mass).

[0052] The purpose of this process is to mix the -1mm tailings remaining after the comprehensive utilization of crushed and dust-recovered slurry and dry-discharged waste rock, in preparation for the magnetic separation process.

[0053] (5) The crushed and dust-recovered slurry and the tailings from step (3) -1mm are subjected to grinding, classification and weak magnetic separation.

[0054] The crushed and dust-recovered slurry and the tailings from step (3) -1mm first enter the pump pool, and then are pumped to the second-stage high-frequency fine screen in the magnetic separation zone for classification. The product on the screen enters the concentration magnetic separation, and the concentrated magnetic separation tailings enter the subsequent tailings disposal operation. The concentrated magnetic separation concentrate enters the second-stage grinding, and the second-stage ball mill discharge returns to the high-frequency fine screen to form a closed loop.

[0055] The screened products undergo secondary and tertiary weak magnetic separation in the magnetic separation area. The tertiary weak magnetic separation concentrate yields qualified iron concentrate. The tailings from the secondary and tertiary weak magnetic separations, along with the concentrated magnetic separation tailings from step (5), are then processed in subsequent tailings disposal operations.

[0056] The aperture of the second-stage high-frequency fine screen is 0.1mm. The purpose of the size constraint is to ensure that the final fineness of the iron concentrate reaches -200 mesh with a content of over 70%.

[0057] The magnetic induction intensity of the secondary weak magnetic separation is controlled at 0.18-0.20 Tesla, the magnetic induction intensity of the tertiary weak magnetic separation is controlled at 0.16-0.18 Tesla, and the magnetic induction intensity of the concentration magnetic separation is controlled at 0.30-0.35 Tesla. The purpose of constraining the magnetic induction intensity is to ensure that the final iron concentrate grade reaches more than 65%.

[0058] The purpose of this process is to recover and separate the magnetic iron minerals in the -1mm tailings remaining after the comprehensive utilization of crushed and dust-removed slurry and dry-disposal waste rock through existing magnetic separation technology, and finally produce iron concentrate products.

[0059] The crushed dry blasting waste rock used in this embodiment was taken from an iron mine in Anhui Province. The chemical multi-element analysis results of the crushed dry blasting waste rock are shown in Table 1, and the yield and grade of each particle size are shown in Table 2.

[0060] Table 1. Multi-element chemical analysis results of crushed and dry-disposal waste rock

[0061] content( 8.8 1.31 8.00 6.06 SiO2 Cu Mn S MgO 40.08 0.0 0.46 0.89 1.98

[0062] Depend on Figure 1 The mineral processing flow chart of the present invention shows the mineral processing method for the comprehensive utilization and simultaneous recovery of extremely low-grade magnetite from crushed waste rock. Under the conditions of 8.82% iron content and 1.31% magnetic iron content in the crushed dry-discarded waste rock, the following stone product and -1mm tailings indicators can be obtained respectively:

[0063] Table 2 Analysis Results of Stone Products and -1mm Tailings Indicators

[0064]

[0065] The slurry recovered from crushing and dust removal was sampled and tested, and the specific indicators are shown in Table 3 below:

[0066] Table 3. Indicators of the slurry

[0067] 31.33 19.50 1.96 0.072

[0068] The -1mm tailings produced after the comprehensive utilization of crushed and dry-disposaled waste rock have high total iron and magnetic iron content, and fine particle size. The valuable minerals have already achieved individual liberation, allowing for the recovery of magnetite through simple beneficiation. The slurry recovered from crushing and dust removal also contains high-grade valuable minerals, and its fine particle size allows it to directly enter the secondary grinding process in ore beneficiation. Both have similar particle size distribution and grade characteristics, and can be blended before entering the existing process. Furthermore, this portion is relatively small in daily production, having minimal impact on the existing ore beneficiation process, and can be directly incorporated into the ore beneficiation process for the recovery of valuable minerals.

[0069] The slurry recovered from crushing and dust removal is mixed with -1mm tailings and then enters the magnetic separation process for separation. Finally, after on-site sampling and testing, the indicators are shown in Table 4 below:

[0070] Table 4 Specific Selection Indicators

[0071] Mixed raw ore 100 18.85 6.32 Iron concentrate 10.05 65.30 65.30 magnetic separation tailings 89.95 13.66 0.72

[0072] The technical solution of this application fully utilizes the combination of "-1mm tailings after comprehensive utilization of crushed and dry-discarded waste rock and slurry recovered from crushing and dust removal". These two minerals have similar particle size compositions and can be mixed and then fed into the existing ore grinding and beneficiation process without increasing the existing ore grinding and beneficiation process, thus achieving the goal of cost reduction and efficiency improvement. In actual application, the mine produces approximately 100,000 tons of slurry and -1mm tailings recovered from dust removal annually. After applying this beneficiation method, approximately 10,500 tons of iron concentrate can be produced annually, and 10,500 tons of tailings backfilling can be reduced. Based on an iron concentrate price of 1,200 yuan / ton and a tailings backfilling cost of 60 yuan / ton, a total benefit of 12.663 million yuan is generated.

Claims

1. A mineral processing method for extracting iron concentrate from -1mm tailings after comprehensive utilization of crushed and dust-recovered slurry and crushed dry-disposal waste rock, characterized in that, The main steps are as follows: (1) Crushing dry-disposal waste rock and screening it once for fine crushing; The crushed dry waste rock undergoes a primary screening process using a double-layer screen. The material oversized by the upper screen enters the fine crusher for further crushing, and the crushed material is returned to the primary screening process. The material oversized by the lower screen is sold directly as stone, while the material undersized by the lower screen enters the sand making machine. (2) Sand making - secondary screening; In step (1), the material under the lower screen enters the sand making machine for stone shaping, and the shaped material enters the secondary screening. The secondary screening uses a double-layer screen. The material overseen by the upper screen is sold directly as stone material II, and the material overseen by the lower screen is sold directly as stone material III. The material underseen by the lower screen enters the wheel-type sand washing machine. (3) Wheel-type sand washing-cyclone grading The material undersized from the lower screen of the secondary screening in step (2) enters the wheel sand washing machine for sand retrieval, and the retrieval sand enters the linear dewatering screen. The material over the linear dewatering screen is sold as stone material; the material under the linear dewatering screen and the overflow from the sand washing machine enter the hydrocyclone for grading, the graded sand enters the linear dewatering screen, and the graded overflow is the -1mm tailings after comprehensive utilization of crushed dry waste stone. (4) Crushing and dust removal recovery of slurry The slurry recovered from crushing and dust removal refers to the slurry produced by mixing water with dust generated during the medium crushing, fine crushing, screening, and dry blasting operations of ore in the crushing process after it has been recovered by a dust removal device. (5) The crushed and dust-recovered slurry and the 1mm tailings from step (3) are subjected to grinding, classification and weak magnetic separation. The crushed and dust-recovered slurry and the tailings from step (3) -1mm first enter the pump pool, and then are pumped to the second-stage high-frequency fine screen in the magnetic separation zone for classification. The product on the screen enters the concentration magnetic separation, and the concentrated magnetic separation tailings enter the subsequent tailings disposal operation. The concentrated magnetic separation concentrate enters the second-stage grinding, and the slurry after the second-stage grinding enters the second-stage high-frequency fine screen for screening, forming a closed-loop circulation. The screened products undergo secondary and tertiary weak magnetic separation in the magnetic separation area. The tertiary weak magnetic separation concentrate yields qualified iron concentrate. The tailings from the secondary and tertiary weak magnetic separations and the concentrated magnetic separation tailings from step (5) are then processed in subsequent tailings disposal operations.

2. The beneficiation method for extracting iron concentrate from -1mm tailings after comprehensive utilization of crushed and dust-recovered slurry and crushed dry-disposal waste rock, as described in claim 1, is characterized in that... The primary screening uses a circular vibrating screen, with the upper screen having a mesh size of 28*28mm and the lower screen having a mesh size of 18*18mm.

3. The beneficiation method for extracting iron concentrate from -1mm tailings after comprehensive utilization of crushed and dust-recovered slurry and crushed dry-disposal waste rock, as described in claim 1, is characterized in that... The sand making machine used is the VSI7100 shaping crusher.

4. The beneficiation method for extracting iron concentrate from -1mm tailings after comprehensive utilization of crushed and dust-recovered slurry and crushed dry-disposal waste rock, as described in claim 1, is characterized in that... The secondary screening uses a circular vibrating screen; the upper screen has a mesh size of 15*15mm, and the lower screen has a mesh size of 5*5mm.

5. The beneficiation method for extracting iron concentrate from -1mm tailings after comprehensive utilization of crushed and dust-recovered slurry and crushed dry-disposal waste rock, as described in claim 1, is characterized in that... The wheel-type sand washing machine used is the Weihai Haiwang sand washing machine, model XS2615.

6. The beneficiation method for extracting iron concentrate from -1mm tailings after comprehensive utilization of crushed and dust-recovered slurry and crushed dry-disposal waste rock, as described in claim 1, is characterized in that... The linear dewatering screen has a mesh size of 0.3mm, and the hydrocyclone used is a Neptune hydrocyclone, model FX350.

7. The beneficiation method for extracting iron concentrate from -1mm tailings after comprehensive utilization of crushed and dust-recovered slurry and crushed dry-disposal waste rock, as described in claim 1, is characterized in that... The aperture of the two-stage high-frequency fine screen is 0.1mm.

8. The beneficiation method for extracting iron concentrate from -1mm tailings after comprehensive utilization of crushed and dust-recovered slurry and crushed dry-disposal waste rock, as described in claim 1, is characterized in that... The magnetic induction intensity of the secondary weak magnetic separation is controlled at 0.18-0.20 Tesla, the magnetic induction intensity of the tertiary weak magnetic separation is controlled at 0.16-0.18 Tesla, and the magnetic induction intensity of the concentrated magnetic separation is controlled at 0.30-0.35 Tesla.

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