深海富含具有开采前景的多金属结核资源，但开采过程会带来诸多环境问题，特别是沉积物扰动形成的羽状流迁移扩散。为评估多金属结核开采过程中沉积物扩散对环境的影响，利用西北太平洋北京先驱多金属结核矿区的表层沉积物和海水样品，通过沉降试验，研究了西北太平洋多金属结核矿区沉积物的沉降特性。结果表明，深海沉积物主要由黏性颗粒组成，中值粒径介于2.57 ~ 4.47 μm，最大粒径为66.9 μm。分析沉降速度与沉积物粒径的关系，受絮凝作用影响黏性颗粒沉降速度增大，沉降开始5 h后样品中值粒径小于0.1 μm，沉降开始14 min后样品光学浓度最大。样品的质量浓度与光学浓度成正相关，通过拟合沉积物质量浓度随时间变化曲线，得到样品质量浓度变化规律，沉降开始14 min后，质量浓度最大，5 h后已沉降至总质量的97.54%。研究结果可以为深海多金属结核开采过程中羽流的环境影响评价提供支持。

The deep-sea is rich in polymetallic nodules resources that are promising for mining, but the process of mining poses a number of environmental problems, in particular the migratory diffusion of plumes formed by sediments disturbance. To evaluate the environmental impact of sediment setting behavior during polymetallic nodule mining, seafloor surface sediments and seawater from the Beijing Pioneer polymetallic nodule mining area in the northwestern Pacific Ocean were employed. Sedimentation experiments were conducted to investigate the deposition characteristics of the suspended sediments. The results indicate that the deep-sea sediments are primarily composed of viscous particles, with median particles sizes ranging from 2.57 to 4.47 μm, and maximum particle size of 66.9μm. The relationship between settling velocity and particle size was analyzed, showing that the settling velocity of viscous particles increased due to flocculation effects. After 5 hours of sedimentation, the median particle size of suspended sediments decreased to below 0.1 μm, and the maximum optical density has observed at 14 minutes after the onset of sedimentation. A positive correlation is observed between the mass concentration and optical density of the suspension. By fitting the temporal variation of sediment mass concentration, the settling pattern is determined. The mass concentration reached its peak 14 minutes after the onset of settling, and decreased to 2.46% of the initial value after 5 hours, indicating that 97.54% of the total mass has settled. These findings provide supporting data for environmental impact assessments related to plume behavior during deep-sea polymetallic nodule mining.