Study on Grinding Characteristics of Nano-composite Ceramic Ball as Magne-tite Fine Grinding Medium
The three-stage grinding process commonly utilizes steel forging or steel balls as the fine grinding medium,resulting in issues such as high energy consumption,high ball consumption,and poor particle size distribution.Introducing a new grinding medium,nano-composite ceramic balls,offers a range of superior properties including high hardness,good wear resistance,low energy consumption,and reduced over-crushing.Despite these advantages,ceramic balls have not yet been incorporated into the three-stage grinding process or fine grinding operations.The study conducted a batch grinding experiment using the three-stage ball mill feed from Jianshan iron mine as the focus of research.The investigation examined the grinding dynamics and statistical properties of steel forging and ceramic balls as fine grinding media,and analyzed the impact of ceramic ball grinding process parameters on product particle size characteristics.Comparison of the mean values of R2 and error in kinetic fitting characteristic parameters revealed a poor fit for the degree of n and first-order linear fitting in ultra-fine grained magnetite.The linear characteristics of ultra-fine grained magnetite grinding dynamics are not readily apparent and exhibit a significant margin of error,yet they predominantly align with first-order grinding dynamics.A comparison of the grinding kinetic parameter k indicates that ceramic balls demonstrate superior fine grinding capabilities compared to steel forging.Additionally,the analysis of particle size characteristics in batch grinding products and fine grade regeneration rates suggests that optimal grinding conditions entail a grinding concentration of 75%,a medium filling rate of 38%,and an ideal mixing ratio of all-ceramic ball diameters at Φ25:Φ20:Φ15 of 50%:30%:20%.The optimal mixing ratio of ceramic balls and steel balls,with diameters of Φ25,Φ20,and Φ15 mm in proportions of 50%,30%,and 20%respectively,resulted in a filling rate of 32%for the mixed porcelain balls.In comparison,using single diameter 30 mm steel balls achieved a filling rate of 6%.Following the implementation of ceramic ball milling in an industrial setting,the power consumption,ball consumption,and overflow product particle size characteristics were monitored over a one-month period.Results showed a 17.52%decrease in ball consumption,a 42.37%reduction in power consumption,and a 32.11%decrease in comprehensive grinding costs,while maintaining the same overflow fineness and iron concentrate grade.The ceramic ball can be used as a new medium to completely replace the steel forging mill.
grinding kineticsnano-composite ceramic ballsteel forgingultrafine magnetitegrinding energy consumptiongrinding characteristics
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