Ore grinding medium adding method for copper-nickel sulfide ore grinding

Abstract

The invention relates to the technical field of non-ferrous metal ore dressing, in particular to an ore grinding medium adding method for copper-nickel sulfide ore grinding, and solves the problems that in the existing copper-nickel sulfide ore grinding process, due to the fact that steel balls and steel forgings are generally adopted as ore grinding media, ore grinding iron pollution is prone to occurring, and the over-grinding or under-grinding phenomenon is caused by uneven disseminated particle size distribution; and finally, the overall flotation quality of the nickel-copper sulfide ore is affected. According to the method, high-chromium balls and high-chromium forgings are used as ore grinding media in first-stage ore grinding, and nano-composite ceramic balls better matched with copper-nickel ore in characteristics are used as ore grinding media in second-stage ore grinding, so that iron ion pollution of a steel ball medium to ore pulp of a flotation system is effectively avoided; meanwhile, the abrasion of the ore grinding medium is reduced due to high hardness of the ore grinding medium; the friction between ore grinding media of the nano composite ceramic balls is small, so that the ore grinding power consumption is effectively reduced; and the ore grinding granularity and concentration are detected in real time through the online analyzer, so that the addition amount of the ore grinding medium is accurately controlled, and the ore is prevented from being over-ground.

Description

Technical Field

[0001] The invention relates to the technical field of nonferrous metal beneficiation, and in particular to a method for adding grinding media for grinding copper-nickel sulfide ore. Background Art

[0002] The flotation process is the most effective separation method for nickel-copper ore and the main method for the separation and enrichment of nickel-copper ore. Grinding is the last necessary process before flotation and plays an important role in the flotation of minerals. The purpose is to fully separate the useful minerals and the gangue without over-grinding, and to improve the particle size products that meet the separation requirements. The existing nickel-copper sulfide ore dressing process has put forward higher requirements for grinding, which requires not only the full dissociation of the mineral monomers, but also the prevention of over-grinding, and the reduction of grinding costs as much as possible. At present, ball mills mainly use steel balls and steel forgings as grinding media, with steel balls used in the first stage of grinding and steel forgings used in the second stage of grinding. The wear resistance of steel balls and steel forgings is poor, resulting in a large consumption of steel materials, and serious wear and tear produces a large amount of iron pollution, which will cover the surface of valuable metal minerals during the grinding process, which is not conducive to subsequent flotation separation operations and the recovery of valuable metal minerals, affecting the mineral processing indicators; the uneven distribution of particle size of the grinding media leads to "over-grinding" or "under-grinding" in the production process, and the particle size distribution of the grinding products is uneven, which can easily affect the product quality of the flotation concentrate; the wear cost of steel balls and steel forgings is high, the grinding efficiency is low, and the power consumption of grinding is large; at the same time, the grinding particle size of the existing grinding system cannot be detected in real time, and the detection of the filling rate of the grinding media is obviously delayed, which has a great impact on the grinding efficiency. Summary of the invention

[0003] The invention provides a method for adding grinding media for grinding copper-nickel sulfide ore, so as to solve the problems existing in the above background that the grinding media adopts steel balls and steel forgings, which are very easy to be polluted by grinding iron, and the uneven distribution of embedded particle size leads to "over-grinding" or "under-grinding", which ultimately affects the overall flotation quality of nickel-copper sulfide ore.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: A method for adding grinding media to copper-nickel sulfide ore grinding comprises the following steps: Step 1: When grinding the copper-nickel sulfide ore, high chromium balls with diameters of φ80 mm and φ90 mm are selected for the first-stage ball mill grinding, and the two specifications of high chromium balls are mixed to prepare the ball mill grinding medium. The filling rate of the ball mill is 32%-37%, and the required amount of high chromium balls added is determined in real time by an online particle size concentration analyzer.

[0005] Step 2: The secondary ball mill uses φ40-45mm high chromium forging as the grinding medium. The filling rate of the ball mill is 32%-36%, and the required high chromium forging addition amount is determined in real time by an online particle size concentration analyzer.

[0006] Step 3, during the second-stage grinding, nano-composite ceramic balls with diameters of φ35mm, φ30mm and φ25mm are mixed in a ratio of φ35mm accounting for 50%-55% of the total mass, φ30mm accounting for 30%-35% of the total mass, and φ25mm accounting for 10%-20% of the total mass as the second-stage ball mill grinding media, the ball mill filling rate is 40%-45%, and the required amount of nano-composite ceramic balls added is determined in real time by an online particle size concentration analyzer.

[0007] Furthermore, the preparation ratio of high chromium balls in the two high chromium ball mixed grinding media is 1:4.

[0008] Furthermore, when high chromium balls and high chromium forging are used in the first stage grinding, the amount of copper-nickel sulfide ore added accounts for 60%-75% of the total slurry weight by dry weight, and when nano-composite ceramic balls are used in the second stage grinding, the amount of copper-nickel sulfide ore added accounts for 60%-68% of the total slurry weight by dry weight.

[0009] Furthermore, the chemical composition and content of the nano-composite ceramic ball are 60%-80% Al2O3, 5%-10% SiO2, 10%-15% Fe2O3, ≥1% CaO, 8-9 Mohs hardness, and 3.7±0.05g / cm³ specific gravity.

[0010] The present invention has the following beneficial effects: The present invention adopts high chromium balls, high chromium forgings and nano-composite ceramic balls instead of steel balls and steel forgings as grinding media. Due to their high hardness, they can effectively reduce the medium wear in the grinding process; at the same time, they effectively reduce the pollution of the flotation system by iron ions caused by the wear and fall of steel ball and steel forging media.

[0011] The present invention selects matching high-chromium balls, high-chromium forgings and nano-composite ceramic ball grinding media in the grinding operation section, and simultaneously uses an online particle size concentration analyzer to detect the grinding particle size and concentration in real time, so that the real-time addition and adjustment of the grinding medium is more accurate, effectively avoiding over-grinding or under-grinding of the copper-nickel sulfide ore, thereby improving the monomer dissociation degree of the mineral, obtaining a grinding product with a more uniform particle size, and creating more favorable conditions for subsequent mineral flotation operations.

[0012] The nano-composite ceramic ball milling medium used in the present invention has a low specific gravity and small friction between the medium and the medium, and between the medium and the copper-nickel sulfide ore, thereby achieving the purpose of greatly reducing the power consumption of grinding. DETAILED DESCRIPTION

[0013] The present invention will be further described below in conjunction with specific embodiments.

[0014] Example 1 A method for adding grinding media to copper-nickel sulfide ore grinding comprises the following steps: Step 1, when grinding the copper-nickel sulfide ore, high chromium balls with diameters of φ80 mm and φ90 mm are selected for the first-stage ball mill grinding. The two high chromium balls are mixed in a ratio of φ80 mm: φ90 mm of 1:4 as the ball mill grinding medium. The filling rate of the ball mill is 32%, and the required amount of high chromium balls added is determined in real time by an online particle size concentration analyzer. The amount of copper-nickel sulfide ore added accounts for 60% of the weight of the entire slurry by dry weight.

[0015] Step 2: A secondary ball mill uses φ40-45 mm high chromium forging as the grinding medium. The filling rate of the ball mill is 32%. The required amount of high chromium forging is determined in real time by an online particle size concentration analyzer. The amount of copper-nickel sulfide ore added accounts for 60% of the total slurry weight by dry weight.

[0016] Step 3, during the second stage grinding, nano-composite ceramic balls with diameters of φ35mm, φ30mm and φ25mm are prepared and mixed in a ratio of φ35mm large balls accounting for 50% of the total mass, φ30mm medium balls accounting for 30% of the total mass, and φ25mm small balls accounting for 20% of the total mass as the second stage ball mill grinding media, the ball mill filling rate is 40%, the grinding concentration is 70%, the amount of sodium hexametaphosphate added as a grinding aid is 150g / t, the chemical composition and content of the nano-composite ceramic balls are Al2O3 accounting for 60%, SiO2 accounting for 5%, Fe2O3 accounting for 10%, CaO accounting for 1%, the Mohs hardness is 8, the density specific gravity is 3.75g / cm³, and the required amount of nano-composite ceramic balls added is determined in real time by an online particle size concentration analyzer, and the amount of copper-nickel sulfide ore added accounts for 60% of the weight of the entire slurry by dry weight.

[0017] Step 4: After the first stage of the secondary ball mill grinding is classified by the cyclone, when the -0.074 mm particle size accounts for ≥60% in the overflow, the copper-nickel sulfide ore particles enter the first stage of the flotation system for selection; after the second stage of the ball mill grinding is classified by the cyclone, when the -0.074 mm particle size accounts for ≥80% in the overflow, the copper-nickel sulfide ore particles enter the second stage of the flotation system for selection.

[0018] In the existing ball mill grinding with steel balls and steel forgings, the unit consumption of steel balls and steel forgings is 0.18kg / t. After using high chromium balls and high chromium forgings, the unit consumption of steel balls is reduced to 0.07kg / t. In addition, the second-stage grinding ball mill adds nano-composite ceramic balls, which reduces the unit consumption of steel balls by 40% compared with the original steel balls. The decline is large, which effectively reduces the mineral processing cost. At the same time, the proportion of materials below -10μm is reduced by 9%, which is more conducive to subsequent mineral flotation operations. At the same time, due to the lighter specific gravity of nano-composite ceramic balls, the ball mill uses nano-composite ceramic balls to reduce power consumption by 20% compared with the original grinding media steel forgings and steel forgings, thereby achieving efficient grinding of copper-nickel sulfide ore.

[0019] Example 2 A method for adding grinding media to copper-nickel sulfide ore grinding comprises the following steps: Step 1, when grinding the copper-nickel sulfide ore, high chromium balls with diameters of φ80 mm and φ90 mm are selected for the first-stage ball mill grinding. The two high chromium balls are mixed in a ratio of φ80 mm: φ90 mm of 1:4 as the ball mill grinding medium. The filling rate of the ball mill is 35%, and the required amount of high chromium balls added is determined in real time by an online particle size concentration analyzer. The amount of copper-nickel sulfide ore added accounts for 70% of the weight of the entire slurry by dry weight.

[0020] Step 2: A secondary ball mill uses φ40-45 mm high chromium forging as the grinding medium. The filling rate of the ball mill is 34%. The required amount of high chromium forging is determined in real time by an online particle size concentration analyzer. The amount of copper-nickel sulfide ore added accounts for 70% of the total slurry weight by dry weight.

[0021] Step 3, during the second stage grinding, nano-composite ceramic balls with diameters of φ35mm, φ30mm and φ25mm are prepared and mixed in a ratio of φ35mm large balls accounting for 52% of the total mass, φ30mm medium balls accounting for 33% of the total mass, and φ25mm small balls accounting for 15% of the total mass as the second stage ball mill grinding media, the ball mill filling rate is 43%, and the grinding concentration is 60%; the amount of sodium hexametaphosphate added as a grinding aid is about 140g / t, the chemical composition and content of the nano-composite ceramic balls are Al2O3 accounting for 70%, SiO2 accounting for 7%, Fe2O3 accounting for 12%, CaO accounting for 2%, the Mohs hardness is 8.5, the density specific gravity is 3.7 / cm³, and the required amount of nano-composite ceramic balls added is determined in real time by an online particle size concentration analyzer, and the amount of copper-nickel sulfide ore added accounts for 65% of the weight of the entire slurry by dry weight.

[0022] Step 4: After the first stage of the secondary ball mill grinding is classified by the cyclone, when the -0.074 mm particle size accounts for ≥60% in the overflow, the copper-nickel sulfide ore particles enter the first stage of the flotation system for selection; after the second stage of the ball mill grinding is classified by the cyclone, when the -0.074 mm particle size accounts for ≥80% in the overflow, the copper-nickel sulfide ore particles enter the second stage of the flotation system for selection.

[0023] In the existing ball mill grinding with steel balls and steel forgings, the unit consumption of steel balls and steel forgings is 0.18kg / t. After using high chromium balls and high chromium forgings, the unit consumption of steel balls is reduced to 0.06kg / t. In addition, the second-stage grinding ball mill adds nano-composite ceramic balls, which is 50% lower than the original steel ball unit consumption. The decline is large, which effectively reduces the mineral processing cost; at the same time, the proportion of materials below -10μm is reduced by 10%, which is more conducive to subsequent mineral flotation operations. At the same time, due to the lighter specific gravity of nano-composite ceramic balls, the ball mill uses nano-composite ceramic balls to reduce power consumption by 30% compared with the original grinding media steel forgings and steel forgings, thereby achieving efficient grinding of copper-nickel sulfide ore.

[0024] Example 3 A method for adding grinding media to copper-nickel sulfide ore grinding comprises the following steps: Step 1, when grinding the copper-nickel sulfide ore, high chromium balls with diameters of φ80 mm and φ90 mm are selected for the first-stage ball mill grinding. The two high chromium balls are mixed in a ratio of φ80 mm: φ90 mm of 1:4 as the ball mill grinding medium. The filling rate of the ball mill is 37%, and the required amount of high chromium balls added is determined in real time by an online particle size concentration analyzer. The amount of copper-nickel sulfide ore added accounts for 75% of the weight of the entire slurry by dry weight.

[0025] Step 2: A secondary ball mill uses φ40-45 mm high chromium forging as the grinding medium. The filling rate of the ball mill is 36%. The required amount of high chromium forging is determined in real time by an online particle size concentration analyzer. The amount of copper-nickel sulfide ore added accounts for 75% of the total slurry weight by dry weight.

[0026] Step 3, during the second stage grinding, nano-composite ceramic balls with diameters of φ35mm, φ30mm and φ25mm are prepared and mixed in a ratio of φ35mm large balls accounting for 55% of the total mass, φ30mm medium balls accounting for 35% of the total mass, and φ25mm small balls accounting for 20% of the total mass as the second stage ball mill grinding media, the ball mill filling rate is 45%, and the grinding concentration is 65%; the amount of sodium hexametaphosphate added as a grinding aid is about 130g / t, the chemical composition and content of the nano-composite ceramic balls are Al2O3 accounting for 80%, SiO2 accounting for 10%, Fe2O3 accounting for 15%, CaO accounting for 3%, Mohs hardness is 9, density specific gravity is 3.65g / cm³, and the required amount of nano-composite ceramic balls added is determined in real time by an online particle size concentration analyzer, and the amount of copper-nickel sulfide ore added accounts for 68% of the weight of the entire slurry by dry weight.

[0027] Step 4: After the first stage of the secondary ball mill grinding is classified by the cyclone, when the -0.074 mm particle size accounts for ≥60% in the overflow, the copper-nickel sulfide ore particles enter the first stage of the flotation system for selection; after the second stage of the ball mill grinding is classified by the cyclone, when the -0.074 mm particle size accounts for ≥80% in the overflow, the copper-nickel sulfide ore particles enter the second stage of the flotation system for selection.

[0028] In the existing ball mill grinding with steel balls and steel forgings, the unit consumption of steel balls and steel forgings is 0.18kg / t. After using high chromium balls and high chromium forgings, the unit consumption of steel balls is reduced to 0.065kg / t. In addition, the second-stage grinding ball mill adds nano-composite ceramic balls, which is 30% lower than the original steel ball unit consumption. The decline is large, which effectively reduces the mineral processing cost; at the same time, the proportion of materials below -10μm is reduced by 8%, which is more conducive to subsequent mineral flotation operations. At the same time, due to the lighter specific gravity of nano-composite ceramic balls, the ball mill uses nano-composite ceramic balls to reduce power consumption by 25% compared with the original grinding media steel forging balls and steel forgings, thereby achieving efficient grinding of copper-nickel sulfide ore.

Claims

1. A method for adding grinding media to copper-nickel sulfide ore grinding, characterized in that: The following steps are involved: Step 1, when grinding the copper-nickel sulfide ore, high chromium balls with diameters of φ80 mm and φ90 mm are selected for the first-stage ball mill grinding, and the two specifications of high chromium balls are mixed to prepare the ball mill grinding medium, the ball mill filling rate is 32%-37%, and the required high chromium ball addition amount is determined in real time by an online particle size concentration analyzer; Step 2: A secondary ball mill uses φ40-45mm high chromium forging as the grinding medium, the filling rate of the ball mill is 32%-36%, and the required high chromium forging addition amount is determined in real time by an online particle size concentration analyzer; Step 3, during the second-stage grinding, nano-composite ceramic balls with diameters of φ35mm, φ30mm and φ25mm are mixed in a ratio of φ35mm accounting for 50%-55% of the total mass, φ30mm accounting for 30%-35% of the total mass, and φ25mm accounting for 10%-20% of the total mass as the second-stage ball mill grinding media, the ball mill filling rate is 40%-45%, and the required amount of nano-composite ceramic balls added is determined in real time by an online particle size concentration analyzer.

2. The method for adding grinding media for grinding copper-nickel sulfide ore according to claim 1, characterized in that: The mixing ratio of high chromium balls in the two high chromium ball mixed grinding media is 1:

4.

3. The method for adding grinding media to copper-nickel sulfide ore according to claim 1, characterized in that: When high chromium balls and high chromium forging are used in the first stage grinding, the amount of copper-nickel sulfide ore added accounts for 60%-75% of the total slurry weight by dry weight. When nano-composite ceramic balls are used in the second stage grinding, the amount of copper-nickel sulfide ore added accounts for 60%-68% of the total slurry weight by dry weight.

4. The method for adding grinding media for grinding copper-nickel sulfide ore according to claim 1, characterized in that: The chemical composition and content of the nano-composite ceramic ball are 60%-80% Al2O3, 5%-10% SiO2, 10%-15% Fe2O3, ≥1% CaO, 8-9 Mohs hardness, and 3.7±0.05g / cm³ specific gravity.