A process for recovering low-grade manganese ore and tailings

Abstract

The invention discloses a process for recovering middlings and tailings from low-grade manganese mines, belonging to the technical field of manganese ore recovery. The raw ore is crushed and then screened and graded. The -15mm particle size is sent to a wet high-intensity magnetic separator for sorting, the +15-25mm particle size is sent to a dry high-intensity magnetic separator for sorting, the +25mm particle size is sent to a cone crusher for intermediate crushing, and the particles are returned to the screening and classification after crushing. The -15mm particle size is sorted by wet high-intensity magnetic separation to obtain medium-fine concentrate, medium-fine middlings, and the Overflow products include: +15-25mm particle size is separated by dry high-intensity magnetic separation to obtain dry concentrate and dry tailings; medium-fine concentrate and dry concentrate are combined into concentrate, dry tailings are crushed by cone crusher and sent to linear screen for classification; +15mm particle size is returned to the fine cone crusher for fine crushing, and the crushed product is returned to the linear screen; -15mm particle size and medium-fine middling are combined and sent to scavenging wet high-intensity magnetic separator for scavenging to obtain scavenging concentrate, scavenging tailings and scavenging overflow.

Description

Technical Field

[0001] The invention belongs to the technical field of manganese ore recovery, and in particular relates to a process for recovering ore and tailings from low-grade manganese mines. Background Art

[0002] Manganese ore is one of the main raw materials for ferroalloy plants and steel mills. At present, the original production process of the manganese powder plant is: 9.41% raw ore is crushed and graded, and magnetic separation is used to select qualified manganese concentrate with a yield of 45.95%, a grade of 15.1%, and a recovery rate of 73.73%; the magnetic separation tailings are swept and selected to produce medium ore with a yield of 19.81% and a grade of 6.39%, and a medium ore recovery rate of 13.45%; the graded output has a yield of 4.74%, a grade of 7.24%, and a recovery rate of 3.64%; the tailings have a yield of 29.50%, a grade of 2.31%, and a recovery rate of 7.24%.

[0003] The problem with the original process is that the qualified concentrate recovery rate is low, only 73.73%, middlings and slimes account for 17.09% of the original ore, and the combined grade of concentrate + middlings + slimes after blending is only 12.12%, which can only be temporarily stored. A large amount of tailings needs to be stored in a slag storage, which has high production and management costs, and there are certain safety hazards in the tailings storage. Summary of the Invention

[0004] Based on this, the purpose of the present invention is to provide a recovery process for low-grade manganese mine ore and tailings to solve the technical problem of low recovery rate of qualified concentrate in existing mineral processing technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a process for recovering low-grade manganese ore and tailings, comprising the following steps:

[0006] Step 1: The raw ore is crushed to less than 175mm by a jaw crusher, and then water is added to the banana screen for classification. The ore is fed into different crushing equipment according to the particle size. The -15mm particle size is sent to the wet high-intensity magnetic separator by a belt conveyor for sorting. The +15-25mm particle size is sent to the dry high-intensity magnetic separator by a belt conveyor for sorting. The +25mm particle size is sent to the cone crusher by a belt conveyor for secondary crushing. The crushed material is combined with the jaw crusher product and returned to the banana screen for classification via a belt conveyor.

[0007] Step 2: -15mm particle size is separated by wet high-intensity magnetic separation to obtain three products: medium-fine concentrate, medium-fine intermediate ore and overflow; +15-25mm particle size is separated by dry high-intensity magnetic separation to obtain dry-separated concentrate and dry-separated tailings;

[0008] Step 3: The medium and fine particle concentrate and the dry separation concentrate in step 2 are combined into concentrate and sent to the concentrate yard for temporary storage via a belt conveyor. The dry separation tailings are crushed by a cone crusher and then sent to the linear screen for classification by a belt conveyor. The +15mm particle size is returned to the fine crushing cone crusher via a belt conveyor for fine crushing. The crushed product returns to the linear screen. The -15mm particle size and the medium and fine particle middlings are combined and sent to the scavenging wet high-intensity magnetic separator via a belt conveyor for scavenging to obtain scavenged concentrate, scavenged tailings and scavenging overflow.

[0009] Furthermore, the scavenged concentrate obtained in step three is selectively layered crushed and then subjected to wet strong magnetic separation to obtain concentrated concentrate, concentrated tailings and concentrated overflow. The concentrated concentrate is transported to the concentrate yard by a forklift and combined with the concentrate to form a total concentrate. The scavenged tailings and the selected tailings are combined into a total tailings and sent to the tailings yard by a belt conveyor.

[0010] In summary, the present invention mainly has the following beneficial effects:

[0011] By adopting the process of the present invention, the comprehensive concentrate grade is increased from 12.12% to 16.2%, the qualified concentrate recovery rate is increased from 73.73% to 90.27%, the amount of concentrate consumed in producing one ton of electrolytic manganese is reduced from 12 tons to 8 tons, the production cost of electrolytic manganese is significantly reduced, the proportion of waste slag emission is reduced by 33.33%, and the basic goal of energy conservation and emission reduction in electrolytic manganese is achieved, with very significant economic and social benefits; all the mine beneficiation tailings are used as raw materials for cement production, realizing tailings-free beneficiation and resource utilization of tailings, saving more than 20 million yuan in tailings pond construction and management costs each year, with very significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0013] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be understood as limiting the present invention.

[0014] The following describes an embodiment of the present invention based on the overall process.

[0015] A process for recovering low-grade manganese ore and tailings, such as Figure 1 As shown, the following steps are included:

[0016] The raw ore is transported to the raw ore bin by mining car or automobile, and then fed into the MC100 jaw crusher for coarse crushing via a vibrating feeder. The crushed products with a particle size of less than 175mm are conveyed to the banana screen for water classification via a belt conveyor. The ore with a particle size of -15mm is conveyed to the wet high-intensity magnetic separator for separation via a belt conveyor, and the ore with a particle size of +15-25mm is conveyed to the dry high-intensity magnetic separator for separation via a belt conveyor; the ore with a particle size of +25mm is conveyed to the cone crusher for secondary crushing via a belt conveyor. The crushed materials are combined with the crushed products of the jaw crusher and returned to the banana screen for classification via a belt conveyor.

[0017] -15mm particle size ore is separated by wet high-intensity magnetic separation to obtain three products: medium-fine concentrate, medium-fine middlings and overflow. +15-25mm particle size ore is separated by dry high-intensity magnetic separation to obtain dry concentrate and dry tailings. The medium-fine concentrate and dry concentrate are combined into concentrate and sent to the concentrate yard for temporary storage by belt conveyor. The dry tailings are crushed by cone crusher and then sent to linear screen for classification by belt conveyor. The +15mm particle size is returned to the fine crushing cone crusher by belt conveyor for fine crushing, and the crushed products are returned to the linear screen. The -15mm particle size and medium-fine middling are combined and sent to scavenging wet high-intensity magnetic separator by belt conveyor for scavenging to obtain scavenging concentrate, scavenging tailings and scavenging overflow.

[0018] The scavenging concentrate is selectively crushed in layers and then selected by wet high-intensity magnetic separation to obtain selected concentrate, selected tailings and selected overflow. The selected concentrate is transported to the concentrate yard by a forklift and merged with the concentrate to form the total concentrate. The scavenging tailings and selected tailings are merged into the total tailings and sent to the tailings yard by a belt conveyor, and then transported to the cement plant by car. All overflows from wet high-intensity magnetic separation operations and dust collected by dust collectors are concentrated in the sand pump pool and pumped to fine-grained high-intensity magnetic separation. After selection, fine-grained concentrate and tailings mud are obtained. These two products are concentrated, precipitated, and dehydrated by filter presses. The fine-grained concentrate and fine-grained tailings are sent to the electrolytic manganese plant.

[0019] The mineral processing products are: concentrate with a grade of ≥15%, middlings with a grade of 6.39% and 7.24%, with a combined grade of 12.12%.

[0020] The middlings were crushed to 5mm and sorted by a magnetic field strength of 9000Os. The results were: ore grade 8.06%, concentrate grade 14.70%, tailings grade 3.51%, and operating recovery rate 74.64%.

[0021] The middlings were crushed to 5mm and sorted by a magnetic field strength of 9000Os. The results were: ore grade 4.58%, concentrate grade 12.22%, tailings grade 2.91%, and operating recovery rate 47.86%.

[0022] The results of the ore slime test are as follows: the fineness of the raw ore is -200 mesh, accounting for 96.14%, the grade is 7.03%, the concentrate grade is 16.85%, the tailings grade is 3.51%, and the operating recovery rate is 63.42%.

[0023] The mineral processing products are: concentrate with grade ≥15% and fine concentrate with grade ≥16%.

[0024] The results of the present invention in actual production are: a 55.05% total concentrate yield from 9.88% manganese ore, a 16.20% qualified manganese concentrate with a recovery rate of 90.27%. Fine-grained high-intensity magnetic separation produces a 2.80% tailings sludge yield, a 3.04% grade, and a 0.86% recovery rate, which can be used to replace double fly ash in electrolytic manganese production. The tailings yield is 42.15%, a 2.08% grade, and an 8.87% recovery rate. The overall concentrate grade is increased from 12.12% to 16.2%, and the qualified concentrate recovery rate is increased from 73.73% to 90.27%. These significant improvements in mineral processing performance have resulted in a highly efficient mineral processing process for low-grade manganese ore.

[0025] The entire production process is a wet operation. After filtration, the industrial wastewater is returned to the high-level water tank for recycling, achieving zero industrial wastewater discharge. No chemical agents are added during the entire mineral processing process, resulting in no adverse impact on the environment.

[0026] Although an embodiment of the present invention has been shown and described, this specific embodiment is merely an explanation of the present invention and is not a limitation of the invention. The specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples. After reading this specification, those skilled in the art may make modifications, substitutions and variations to the embodiment without creative contribution as needed without departing from the principles and purpose of the present invention. However, as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A process for recovering low-grade manganese ore and tailings, characterized by: The following steps are involved: Step 1: The raw ore is crushed to less than 175mm by a jaw crusher, and then water is added to the banana screen for classification. The ore is fed into different crushing equipment according to the particle size. The -15mm particle size is sent to the wet high-intensity magnetic separator by a belt conveyor for sorting. The +15-25mm particle size is sent to the dry high-intensity magnetic separator by a belt conveyor for sorting. The +25mm particle size is sent to the cone crusher by a belt conveyor for secondary crushing. The crushed material is combined with the jaw crusher product and returned to the banana screen for classification via a belt conveyor. Step 2: -15mm particle size is separated by wet high-intensity magnetic separation to obtain three products: medium-fine concentrate, medium-fine intermediate ore and overflow; +15-25mm particle size is separated by dry high-intensity magnetic separation to obtain dry-separated concentrate and dry-separated tailings; Step 3: The medium and fine particle concentrate and the dry separation concentrate in step 2 are combined into concentrate and sent to the concentrate yard for temporary storage via a belt conveyor. The dry separation tailings are crushed by a cone crusher and then sent to the linear screen for classification by a belt conveyor. The +15mm particle size is returned to the fine crushing cone crusher via a belt conveyor for fine crushing. The crushed product returns to the linear screen. The -15mm particle size and the medium and fine particle middlings are combined and sent to the scavenging wet high-intensity magnetic separator via a belt conveyor for scavenging to obtain scavenged concentrate, scavenged tailings and scavenging overflow.

2. The process for recovering low-grade manganese ore and tailings according to claim 1, characterized in that: The scavenging concentrate obtained in the step 3 is selectively layered crushed and then subjected to wet strong magnetic separation to obtain concentrated concentrate, concentrated tailings and concentrated overflow. The concentrated concentrate is transported to the concentrate yard by a forklift and combined with the concentrate to form a total concentrate. The scavenging tailings and the concentrated tailings are combined into a total tailings and sent to the tailings yard by a belt conveyor.

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