A magnetic separation process for low-grade manganese carbonate ore using the dispersant sodium maleate-acrylate copolymer

Abstract

The present invention discloses a magnetic separation process for low-grade manganese carbonate ore using the dispersant sodium maleate-acrylate copolymer. The manganese carbonate ore is crushed and screened to less than 2 mm, piled into a cone, mixed evenly and bagged. Take the prepared manganese carbonate ore, add tap water and sodium maleate-acrylate copolymer in proportion, mix and put them into a rod mill for grinding for 3 min. The manganese carbonate ore particles are rod-milled to a grinding particle size where the proportion of particles less than 75 μm accounts for 62.71 wt%, and the milled pulp is concentrated to within the range of 16.7 wt% to 20 wt%. The obtained magnetic separation pulp is added to a high-gradient magnetic separator for "one roughing and one scavenging" magnetic separation; the rough concentrate manganese concentrate I, the scavenged manganese concentrate II and the tailings are obtained. By adding the sodium maleate-acrylate copolymer dispersant in the grinding stage in the present invention, the comprehensive manganese ore grade can be increased from 11.27% to 18.15%, the manganese recovery rate can reach 91.19%, and the manganese grade of the tailings is reduced to 2.57%.

Description

Technical Field

[0001] The present invention belongs to the field of magnetic separation of salt minerals, specifically to the technical field of slime dispersion in the magnetic separation of manganese carbonate ore, and particularly relates to the application of a dispersant, sodium maleate-acrylate copolymer, in the magnetic separation of low-grade manganese carbonate ore. Technical Field

[0003] In China, manganese carbonate ore is the main manganese ore resource, but the ore grade is low. According to statistics, low-grade manganese carbonate ore accounts for more than 80% of China's manganese ore resources, and has the characteristics of "poor, miscellaneous, fine, and dispersed", with low grade, high calcium and magnesium content, complex associated components, extremely fine dissemination size, and large manganese deposits also having high iron, high silicon, fine particle size, and difficult beneficiation and smelting.

[0004] Guizhou has become the province with the most manganese resources in China. As of 2022, the cumulative identified resource reserves of four super-large manganese mines in PuJue, GaoDi, DaoTuo, and TaoZiPing in Tongren area are 708 million tons, and it is estimated that the manganese resource reserves in Guizhou exceed 1 billion tons, ranking first in China. However, the high-grade manganese carbonate ore resources in this area are scarce, mainly low-grade manganese carbonate ore, and the mineral composition is complex and diverse, especially the large content of clay minerals, and the rhodochrosite is brittle, making the separation difficult.

[0005] The manganese-containing minerals in manganese carbonate ore mainly exist in the forms of kutnohorite, manganese dolomite, and manganese siderite, and the gangue minerals mainly exist in the forms of quartz, clay minerals (illite and chlorite), albite, etc. Due to the large amount of electrolytic manganese slag, it brings great pressure to the slag yard and the environment. Enriching manganese and discharging tailings through beneficiation technology is the best way to achieve the reduction of electrolytic manganese slag emissions. Therefore, in recent years, the research and development of low-grade manganese carbonate ore beneficiation technology have attracted much attention. By using beneficiation technology to increase the manganese grade by more than 5 percentage points, the beneficiation recovery rate > 90%, and the source reduction of manganese slag > 30%, in order to contribute to the reduction of slag emissions in the electrolytic manganese industry. Rhodochrosite belongs to weakly magnetic minerals, and quartz and illite in gangue minerals belong to diamagnetic and paramagnetic respectively. Under the current technical conditions, magnetic separation is still the main method for the separation of manganese carbonate ore, especially for manganese carbonate ore with high contents of quartz and clay minerals. Due to the brittleness of rhodochrosite and the presence of clay minerals, it will affect the separation effect of magnetic separation to a certain extent.

[0006] At present, the high-gradient magnetic separation process for low-grade manganese carbonate ore is an effective beneficiation technology for recovering manganese-containing minerals, but there is a bottleneck in the improvement of the manganese recovery rate in the obtained manganese concentrate, that is, it is difficult to reduce the manganese content in the separation tailings to less than 4%. Therefore, it is necessary to develop a magnetic separation method for low-grade manganese carbonate ore that can improve the beneficiation index of manganese concentrate. Summary of the Invention

[0007] The object of the present invention is to provide a magnetic separation process for low-grade manganese carbonate ore using the dispersant sodium maleate-acrylate copolymer, which can improve the recovery rate of manganese in the manganese carbonate concentrate while ensuring the quality of the manganese carbonate concentrate, and minimize the loss of manganese in the tailings to the greatest extent.

[0008] To achieve the above object, the solution of the present invention is as follows:

[0009] A magnetic separation process for low-grade manganese carbonate ore using the dispersant sodium maleate-acrylate copolymer, and its specific operation steps are as follows:

[0010] Step a: Crush and screen the manganese carbonate ore to less than 2 mm, pile it into a cone, mix it evenly and bag it for magnetic separation.

[0011] Step b: Take the manganese carbonate ore prepared in step a, mix it according to the ratio of adding 100 mL of tap water per 200 g of manganese carbonate ore, and add sodium maleate-acrylate copolymer in an amount of 200 g - 700 g per ton. The preferred dosage of sodium maleate-acrylate copolymer is 500 g / t, which is used to reduce the mineral slime caused by grinding. Then mix and put it into a rod mill for grinding for 3 minutes, and rod mill the manganese carbonate ore particles to a grinding particle size with a proportion of less than 75 μm accounting for 62.71 wt%. The ore pulp after grinding is concentrated to within the range of 16.7 wt% - 20 wt%.

[0012] Step c: Add the magnetic separation ore pulp obtained in step b to a high-gradient magnetic separator for "one roughing and one scavenging" magnetic separation; adjust the magnetic field strength to 0.9 T - 1.0 T, and the preferred magnetic field strength is 1.0 T for the first-stage roughing of the magnetic separation ore pulp to obtain the rough concentrate manganese concentrate I and the roughing tailings; adjust the magnetic field strength to 1.3 T - 1.4 T, and the preferred magnetic field strength is 1.4 T for the second-stage scavenging of the roughing tailings obtained in the first-stage roughing to obtain the scavenging manganese concentrate II and the tailings.

[0013] In the above step b, the reason for specifying that the grinding particle size of the rod-milled manganese carbonate ore has a proportion of less than 75 μm accounting for 62.71 wt% is as follows: The grade of the useful element Mn in the low-grade manganese carbonate ore is 11.27%, and the harmful elements are TFe 2.52%, CaO 3.93%, MgO 2.37%, P2O5 0.48%, SO3 5.15%, Al2O3 9.81%, SiO2 40.04%, K2O 2.32%, Na2O 1.16%. The manganese-containing minerals are rhodochrosite 20.10% and manganese dolomite 6.00%. The magnesium-containing minerals are mainly dolomite 14.30%. The silicon-containing minerals are quartz 26.40%, illite 19.30% and albite 9.60%. The iron-containing minerals are mainly pyrite 2.80%. The content of clay minerals is high, which is extremely likely to affect the separation of rhodochrosite from gangue minerals, and at the same time limits the improvement space of the grade of the manganese carbonate concentrate.

[0014] In step c, the pulsating water flow of the high-gradient magnetic separator is set to 150 r / min.

[0015] After the grades of the rough-selected manganese concentrate I and the scavenged manganese concentrate II in step c are measured respectively, the grade of the magnetic-separated comprehensive manganese concentrate is obtained through weighted average.

[0016] Adopting the above technical solution, the advantages of the present invention are as follows:

[0017] In the present invention, 500 g / t of sodium maleate-acrylate copolymer dispersant is added in the grinding stage. This reagent is phosphorus-free, non-toxic, and pollution-free, and is an environmentally friendly chemical additive. It has excellent chelating and dispersing capabilities, can effectively reduce the slime content in grinding, reduce the content of secondary slime, improve the adverse effects of slime in the high-gradient magnetic separation process, and has a significant enhancing effect on the separation of low-grade manganese carbonate ore, with better beneficiation indexes for the separation of target minerals.

[0018] In the present invention, high-gradient magnetic separation is selected to perform strong magnetic separation on low-grade manganese carbonate ore. The rough-selection magnetic field intensity is 1.0 T, and the scavenging magnetic field intensity is 1.4 T. This magnetic separation process has a short flow and low energy consumption. Through two-stage magnetic separation, the grade of the comprehensive manganese ore can be increased from 11.27% to 18.15%, the manganese recovery rate can reach 91.19%, and the manganese grade of the tailings is reduced to 2.57%. These data are better than the existing manganese ore magnetic separation processes, and satisfactory beneficiation indexes of manganese carbonate concentrate are obtained. Description of the Drawings

[0019] Figure 1 is the process flow chart of the present invention. Detailed Embodiments

[0020] Combined with Figure 1 , the present invention is further described.

[0021] I. A low-grade manganese carbonate ore magnetic separation process applying the dispersant sodium maleate-acrylate copolymer disclosed by the present invention, and its operation steps are as follows:

[0022] Step a: Crush and screen the low-grade manganese carbonate ore (raw ore) to less than 2 mm, stack it in a cone, mix it evenly and bag it for magnetic separation use. The grade of the useful element Mn in the low-grade manganese carbonate ore is 11.27%.

[0023] Step b: Take the manganese carbonate ore prepared in step a, mix it according to the ratio of adding 100 mL of tap water per 200 g of manganese carbonate ore, and add the dispersant sodium maleate-acrylate copolymer in different amounts. Then mix and put it into a rod mill for grinding for 3 min, grind the manganese carbonate ore particles to a grinding particle size with less than 75 μm accounting for 62.71 wt%, and concentrate the ground ore pulp to the range of 16.7 wt% - 20 wt%.

[0024] Step c: Add the magnetic separation pulp obtained in step b to a high-gradient magnetic separator for "one roughing and one scavenging" magnetic separation to obtain rough manganese concentrate I, scavenged manganese concentrate II, and tailings.

[0025] In step c, after measuring the grades of rough manganese concentrate I and scavenged manganese concentrate II respectively, the grade of the magnetic separation comprehensive manganese concentrate is obtained through weighted average.

[0026] According to the above operation steps, specific embodiments of the present invention are as follows:

[0027] Example 1:

[0028] (1) Without adding sodium maleate-acrylate copolymer (MA-AA·Na) dispersant, rod mill the low-grade manganese carbonate ore until the grinding particle size is less than 75 μm, accounting for 62.71 wt%. Under the magnetic separation conditions of one roughing at 0.9 T and one scavenging at 1.3 T for the original ore pulp, the grade of the comprehensive manganese concentrate is 18.89%, the manganese recovery rate is 84.36%, and the manganese grade in the tailings is 3.96%.

[0029]

[0030] (2) Add 200 g / t of sodium maleate-acrylate copolymer (MA-AA·Na) dispersant, rod mill the low-grade manganese carbonate ore until the grinding particle size is less than 75 μm, accounting for 62.71 wt%. Under the magnetic separation conditions of one roughing at 0.9 T and one scavenging at 1.3 T for the original ore pulp, the grade of the comprehensive manganese concentrate is 18.89%, the manganese recovery rate is 86.78%, and the manganese grade in the tailings is 3.35%.

[0031]

[0032] (3) Add 500 g / t of sodium maleate-acrylate copolymer (MA-AA·Na) dispersant, rod mill the low-grade manganese carbonate ore until the grinding particle size is less than 75 μm, accounting for 62.71 wt%. Under the magnetic separation conditions of one roughing at 0.9 T and one scavenging at 1.3 T for the original ore pulp, the grade of the comprehensive manganese concentrate is 19.09%, the manganese recovery rate is 87.05%, and the manganese grade in the tailings is 3.18%.

[0033]

[0034] Example 2:

[0035] (1) Without adding sodium maleate-acrylate copolymer (MA-AA·Na) dispersant, rod mill the low-grade manganese carbonate ore until the grinding particle size is less than 75 μm, accounting for 62.71 wt%. Under the magnetic separation conditions of one roughing at 1.0 T and one scavenging at 1.3 T for the original ore pulp, the grade of the comprehensive manganese concentrate is 17.52%, the manganese recovery rate is 83.76%, and the manganese grade in the tailings is 4.57%.

[0036]

[0037]

[0038] (2) Add 200 g / t of sodium maleate-acrylate copolymer (MA-AA·Na) dispersant, rod mill the low-grade manganese carbonate ore to a grinding particle size with less than 75 μm accounting for 62.71 wt%, under the magnetic separation conditions of 1.0 T for the first roughing and 1.3 T for the first scavenging of the original ore pulp, the comprehensive manganese concentrate grade is 18.12%, the manganese recovery rate is 86.86%, and the manganese grade in the tailings is 3.48%.

[0039]

[0040] (3) Add 500 g / t of sodium maleate-acrylate copolymer (MA-AA·Na) dispersant, rod mill the low-grade manganese carbonate ore to a grinding particle size with less than 75 μm accounting for 62.71 wt%, under the magnetic separation conditions of 1.0 T for the first roughing and 1.3 T for the first scavenging of the original ore pulp, the comprehensive manganese concentrate grade is 18.01%, the manganese recovery rate is 89.97%, and the manganese grade in the tailings is 2.78%.

[0041]

[0042] Example 3:

[0043] (1) Without adding sodium maleate-acrylate copolymer (MA-AA·Na) dispersant, rod mill the low-grade manganese carbonate ore to a grinding particle size with less than 75 μm accounting for 62.71 wt%, under the magnetic separation conditions of 1.0 T for the first roughing and 1.4 T for the first scavenging of the original ore pulp, the comprehensive manganese concentrate grade is 18.91%, the manganese recovery rate is 81.67%, and the manganese grade in the tailings is 4.43%.

[0044]

[0045] (2) Add 200 g / t of sodium maleate-acrylate copolymer (MA-AA·Na) dispersant, rod mill the low-grade manganese carbonate ore to a grinding particle size with less than 75 μm accounting for 62.71 wt%, under the magnetic separation conditions of 1.0 T for the first roughing and 1.4 T for the first scavenging of the original ore pulp, the comprehensive manganese concentrate grade is 17.83%, the manganese recovery rate is 88.45%, and the manganese grade in the tailings is 3.19%.

[0046]

[0047] (3) Add 500 g / t of sodium maleate-acrylate copolymer (MA-AA·Na) dispersant, rod mill the low-grade manganese carbonate ore until the grinding particle size is less than 75 μm and the proportion accounts for 62.71 wt%. Under the magnetic separation conditions of 1.0 T for the first rough selection and 1.4 T for the first scavenging selection of the original ore pulp, the comprehensive manganese concentrate grade is 18.15%, the manganese recovery rate is 91.19%, and the manganese grade in the tailings is 2.57%.

[0048]

[0049] II. The operation steps of the comparative example are as follows:

[0050] Step a: Crush and screen the manganese carbonate ore to less than 2 mm, stack it in a cone, mix it evenly and bag it for magnetic separation. The grade of the useful element Mn in the low-grade manganese carbonate ore is 11.27%.

[0051] Step b1: Take the manganese carbonate ore prepared in step a, mix it in the ratio of adding 100 mL of tap water to every 200 g of manganese carbonate ore, put it into a rod mill for grinding for 3 min. After grinding to a particle size less than 75 μm with a proportion of 62.71 wt%, add different amounts of sodium maleate-acrylate copolymer (MA-AA·Na) dispersant to the ore pulp concentrated within the range of 16.7 wt% - 20 wt%, and stir the mixture for 3 min.

[0052] Step c1: Add the magnetic separation ore pulp obtained in step b1 to a high-gradient magnetic separator, and perform "one roughing and one scavenging" magnetic separation to obtain roughing concentrate I, scavenging concentrate II and tailings. After measuring the grades of the roughing manganese concentrate I and the scavenging manganese concentrate II in step c1 respectively, the comprehensive manganese concentrate grade of magnetic separation is obtained through weighted average.

[0053] According to this operation step, the specific examples of the comparative example are as follows:

[0054] Comparative Example 4:

[0055] (1) Rod mill the low-grade manganese carbonate ore until the grinding particle size is less than 75 μm and the proportion accounts for 62.71 wt%. Concentrate the ore pulp within the range of 16.7 wt% - 20 wt%. Add 200 g / t of sodium maleate-acrylate copolymer (MA-AA·Na) dispersant to the ore pulp. Under the magnetic separation conditions of 1.0 T for the first rough selection and 1.4 T for the first scavenging selection of the original ore pulp, the comprehensive manganese concentrate grade is 17.89%, the manganese recovery rate is 86.18%, and the manganese grade in the tailings is 3.59%.

[0056]

[0057]

[0058] (2) The low-grade manganese carbonate ore is rod-milled until the proportion of the grinding particle size less than 75 μm accounts for 62.71 wt%. The pulp is concentrated to the range of 16.7 wt% - 20 wt%. A dispersant of 500 g / t sodium maleate-acrylate copolymer (MA-AA·Na) is added to the pulp. Under the magnetic separation conditions of 1.0 T for the first rough selection and 1.4 T for the first scavenging selection of the original pulp, the comprehensive manganese concentrate grade is 17.38%, the manganese recovery rate is 87.39%, and the manganese grade in the tailings is 3.39%.

[0059]

[0060] III. Summary

[0061] In the present invention, the low-grade manganese carbonate ore is rod-milled, and the proportion of the grinding particle size less than 75 μm accounts for 62.71 wt%. For the first time, a method combining a sodium maleate-acrylate copolymer (MA-AA·Na) dispersant with the "one roughing and one scavenging" process flow is used. The dispersant is added during grinding for the purpose of grinding, which is beneficial to avoiding wrapping or entrainment during the magnetic separation process, creating conditions for improving the manganese concentrate beneficiation index, increasing the comprehensive manganese carbonate concentrate grade by 6.70%, with a recovery rate of 91.19%, and reducing the manganese grade in the tailings to 2.57%.

[0062] The present invention applies sodium maleate-acrylate copolymer (MA-AA·Na) to the magnetic separation process of low-grade manganese carbonate ore with a high clay mineral content, providing technical support for obtaining high-quality manganese carbonate concentrate and ensuring the maximum reduction of electrolytic manganese slag emissions, and is of great significance for the development and utilization of separating low-grade manganese carbonate ore.

[0063] The present invention has been disclosed above with preferred embodiments, but it does not limit the present invention. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the essence and scope of the present invention shall be included within the protection scope of the present invention.

Claims

1. A magnetic separation process for low-grade manganese carbonate ore using the dispersant sodium maleate-acrylate copolymer, characterized in that The operation steps are as follows: Step a: Crush and screen the manganese carbonate ore to less than 2 mm, stack it in a cone, mix well and bag it for magnetic separation; Step b: Take the manganese carbonate ore prepared in step a, mix it according to the ratio of adding 100 ml of tap water per 200 g of manganese carbonate ore, and add sodium maleate-acrylate copolymer in an amount of 200 - 700 g per ton. Mix and put it into a rod mill for grinding for 3 min. Grind the manganese carbonate ore particles until the grinding particle size is less than 75 μm and the proportion is 62.71 wt%. Concentrate the ground ore pulp to within the range of 16.7 wt% - 20 wt%; Step c: Add the magnetic separation ore pulp obtained in step b to a high-gradient magnetic separator for "one roughing and one scavenging" magnetic separation; Adjust the magnetic field strength to 0.9 - 1.0 T for the first-stage roughing of the magnetic separation ore pulp to obtain rough concentrate manganese I and roughing tailings; Adjust the magnetic field strength to 1.3 - 1.4 T and conduct the second-stage scavenging of the roughing tailings obtained from the first-stage roughing to obtain scavenged concentrate manganese II and tailings.

2. The low-grade manganese carbonate ore magnetic separation process using the dispersant sodium maleate-acrylate copolymer as claimed in claim 1, wherein: In step b, the dosage of sodium maleate-acrylate copolymer is 500 g / t.

3. The low-grade manganese carbonate ore magnetic separation process using the dispersant sodium maleate-acrylate copolymer as claimed in claim 1, characterized in that: In step c, the magnetic field strength for the first-stage roughing is 1.0 T.

4. A low-grade manganese carbonate ore magnetic separation process using sodium salt of maleic acid-acrylic acid copolymer as dispersant, characterized in that: In step c, the magnetic field strength for the second-stage scavenging is 1.4 T.

5. The low-grade manganese carbonate ore magnetic separation process using the dispersant sodium maleate-acrylate copolymer as claimed in claim 1, characterized in that: In step c, the pulsating water flow of the high-gradient magnetic separator is set to 150 r / min.

6. The low-grade manganese carbonate ore magnetic separation process using sodium salt of maleic acid-acrylic acid copolymer dispersant as claimed in claim 1, characterized in that: In step a, the manganese carbonate ore is of low grade. In the low-grade manganese carbonate ore, the grade of the useful element Mn is 11.27%, and the harmful elements are TFe 2.52%, CaO 3.93%, MgO 2.37%, P2O5 0.48%, SO3 5.15%, Al2O3 9.81%, SiO2 40.04%, K2O 2.32%, Na2O 1.16%.

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