Nickel laterite ore is an important nickel-bearing mineral.Research on pre-heating and hydrogen pre-reduction in the pyrometallurgical process of nickel laterite ore is very limited,especially when using fluidized bed...Nickel laterite ore is an important nickel-bearing mineral.Research on pre-heating and hydrogen pre-reduction in the pyrometallurgical process of nickel laterite ore is very limited,especially when using fluidized bed roasting.This study systematically explores the mechanisms of fluidized bed pre-heating treatment and hydrogen pre-reduction in the roasting process of saprolitic nickel laterite ore.According to single-factor experiment results,the appropriate pre-heating and pre-reduction conditions were a pre-heating temperature of 700℃,a pre-heating time of 30 min,a pre-reduction temperature of 700℃,a pre-reduction time of 30 min,and a hydrogen concentration of 80%.Then,the nickel metallization rate and iron metallization rate reached 90.56%and 41.31%,respectively.Various analytical and testing methods were employed to study the changes in phase composition,magnetism,surface element valence states,and microstructure of nickel laterite ore during fluidized pre-heating and pre-reduction.The study shows that hydrogen can achieve nickel reduction at relatively low temperatures.It was also found that pre-heating treatment of nickel laterite ore is beneficial.Pre-heating opens up the mineral structures of serpentine and limonite,allowing the reducing gas and nickel to interact quickly during the reduction process,enhancing the pre-reduction process.展开更多
目的:开发含椰子粉的发酵型烘焙食品。方法:采用TA.XT Plus C物性测试仪的全质构压缩试验和F4肖邦发酵流变仪测定椰子粉—小麦粉面团质构和发酵流变学特性。结果:椰子粉的添加显著提高了面团的硬度、咀嚼性和胶着性。但其对弹性和黏性...目的:开发含椰子粉的发酵型烘焙食品。方法:采用TA.XT Plus C物性测试仪的全质构压缩试验和F4肖邦发酵流变仪测定椰子粉—小麦粉面团质构和发酵流变学特性。结果:椰子粉的添加显著提高了面团的硬度、咀嚼性和胶着性。但其对弹性和黏性的影响不一,添加3%椰子粉的面团表现出较硬、发酵延迟、体积小等面团发酵性能的降低,而添加1%和5%椰子粉的面团出现高度坍塌、漏气等稳定持气能力不足的现象。此外,添加1%的椰子粉时,面团的面筋网络结构明显断裂,呈不规则的片状;当进一步添加椰子粉(3%)时,面团的面筋网络结构逐渐变得稀疏。而当椰子粉的添加量增加至5%时,面筋断裂结构却得到明显改善。结论:椰子粉的添加改变了面团的质构特性进而降低了其发酵流变学特性。低含量的椰子粉破坏了面筋网络结构,而高含量的椰子粉可以改善面筋网络结构,增强面团的连续性。展开更多
基金Project(2023JH3/10200010)supported by the Excellent Youth Natural Science Foundation of Liaoning Province,ChinaProject(XLYC2203167)supported by the Liaoning Revitalization Talents Program,China+2 种基金Project(RC231175)supported by the Mid-career and Young Scientific and Technological Talents Program of Shenyang,ChinaProject(2023A03003-2)supported by the Key Special Program of Xinjiang,ChinaProject(N2301026)supported by the Fundamental Research Funds for the Central Universities,China。
文摘Nickel laterite ore is an important nickel-bearing mineral.Research on pre-heating and hydrogen pre-reduction in the pyrometallurgical process of nickel laterite ore is very limited,especially when using fluidized bed roasting.This study systematically explores the mechanisms of fluidized bed pre-heating treatment and hydrogen pre-reduction in the roasting process of saprolitic nickel laterite ore.According to single-factor experiment results,the appropriate pre-heating and pre-reduction conditions were a pre-heating temperature of 700℃,a pre-heating time of 30 min,a pre-reduction temperature of 700℃,a pre-reduction time of 30 min,and a hydrogen concentration of 80%.Then,the nickel metallization rate and iron metallization rate reached 90.56%and 41.31%,respectively.Various analytical and testing methods were employed to study the changes in phase composition,magnetism,surface element valence states,and microstructure of nickel laterite ore during fluidized pre-heating and pre-reduction.The study shows that hydrogen can achieve nickel reduction at relatively low temperatures.It was also found that pre-heating treatment of nickel laterite ore is beneficial.Pre-heating opens up the mineral structures of serpentine and limonite,allowing the reducing gas and nickel to interact quickly during the reduction process,enhancing the pre-reduction process.
文摘目的:开发含椰子粉的发酵型烘焙食品。方法:采用TA.XT Plus C物性测试仪的全质构压缩试验和F4肖邦发酵流变仪测定椰子粉—小麦粉面团质构和发酵流变学特性。结果:椰子粉的添加显著提高了面团的硬度、咀嚼性和胶着性。但其对弹性和黏性的影响不一,添加3%椰子粉的面团表现出较硬、发酵延迟、体积小等面团发酵性能的降低,而添加1%和5%椰子粉的面团出现高度坍塌、漏气等稳定持气能力不足的现象。此外,添加1%的椰子粉时,面团的面筋网络结构明显断裂,呈不规则的片状;当进一步添加椰子粉(3%)时,面团的面筋网络结构逐渐变得稀疏。而当椰子粉的添加量增加至5%时,面筋断裂结构却得到明显改善。结论:椰子粉的添加改变了面团的质构特性进而降低了其发酵流变学特性。低含量的椰子粉破坏了面筋网络结构,而高含量的椰子粉可以改善面筋网络结构,增强面团的连续性。
