Vol.31No.1Feb.，2023采选技术与矿山管理170efficiencywereusedasevaluationindicatorstostudytheoptimizationofthesizeandratioofsteelballsinthemill.Afteroptimization，comparedwiththeon-sitescheme，theyieldof+0.150mmover-coarsegradesoftherecommendedschemeisreducedby2.38percentagepoints，thegrindingfinenessof-0.074mmisincreasedby5.14percentagepoints，andtheyieldoftheintermediategrade（−0.150+0.010mm）isincreasedby1.08percen-tagepoints.Theefficiencyofgrindingtechnologyincreasedby3.39percentagepoints.ItshowsthatusingtherecommendedratioofinitiallychargedsteelballsasthegrindingmediumofYimenCopper’sΦ2.4×3.6mballmillhasobviousoptimizationeffect.Onthepremiseofimprovingthegrindingfineness，theintermediategradeyieldisincreased，andtheover-coarsegradeisreduced.Theproductionratecaneffectivelyimprovetheeffi-ciencyofgrindingtechnology，andachievetheimprovementofgrindingtechnicalindicatorsofthedressingplant，whichisofgreatsignificancetoimprovingtheefficiencyandreducingconsumptionofthedressingplant.Keywords：ballmill；mediumratio；grindingproducts；grindingoptimization；intermediatefraction；recom-mendedsteelballratio美国启动国防材料回收技术创新计划据Mining.com报道，伍斯特理工学院（WPI，WorcesterPolytechnicInstitute）和美国陆军作战能力发展司令部（USACCDC，USArmyCombatCa⁃pabilitiesDevelopmentCommand）下属陆军研究实验室（ARL，ArmyResearchLaboratory）启动一项计划，目的是识别关键矿产和材料供应链风险，比如许多军事装备所需的耐高温高性能合金生产用稀土金属。此项计划被称为“重构国防供应材料回收技术创新”（MaterialsRecoveryTechnologiesforDefenseSupplyResiliencyinitiative），可获得国防部高达2500万美元的资助，目的是保障关键供应不时之需，减少制造业对国外资源的依赖，为美国在全球的军事活动提供帮助。由7家美国内外大学和6家行业实体参与的这个项目获得了国会760万美元的资助。“我们国家的安全保障完全依赖各方面材料的持续供应。因此，回收和循环利用在维持供应链弹性中发挥着重要作用”，WPI参与此项计划的布拉詹德拉·米什拉（BrajendraMishra）教授在媒体声明中称。“此项努力将维持产品和技术向国防部和工业基地的流入...
