A clear understanding of the evolution characteristics of leaching solution’s damage to the basement rock of ion-adsorbed rare earth deposits is essential in the in situ leaching mining.In this study,some laboratory ...A clear understanding of the evolution characteristics of leaching solution’s damage to the basement rock of ion-adsorbed rare earth deposits is essential in the in situ leaching mining.In this study,some laboratory tests were carried out to investigate the deterioration behavior and failure mechanism of rock under the erosion of leaching solution.For this purpose,granite specimens were soaked in the leaching solution for different periods and then some physical and mechanical parameters were measured.The experimental results show that the strength of the rock without any soaking is the maximum.After 60 d,the rock strength,mass(dry)and P-wave velocity(dry)decrease to the minimum,while the porosity of the specimens reaches the maximum.Moreover,the failure pattern of the specimens in the uniaxial compression tests is affected as the soaking time increases.The scanning electron microscopy(SEM)image results indicate that the erosion of quartz crystals inside the rock specimens gets more intense with the increase of soaking time.Also,the internal crystal failure mode gradually changes from the trans-granular to the inter-granular.The insights gained from this study are helpful for better understanding the evolution characteristics of leaching solution’s damage to the basement rock of ionadsorbed rare earth deposits.展开更多
A laboratory incubation experiment (20℃) was conducted to find if the detrimental effects of seed-soaked Cu on wheat seedlings can be minimized by reducing time duration of seed in contact with Cu EDTA fertilizer sol...A laboratory incubation experiment (20℃) was conducted to find if the detrimental effects of seed-soaked Cu on wheat seedlings can be minimized by reducing time duration of seed in contact with Cu EDTA fertilizer solution. The 24 treatments in a 6 x 4 factorial arrangement included 6 rates/amounts of Cu (0, 15, 30, 60, 120 and 240 g Cu 100 kg-1 seed) and 4 seed-soaking time durations (0, 4, 8 and 16 h). The germination of wheat seed was 100% in the zero-Cu control treatments, irrespective of the duration of seed soaking time. However, seed germination decreased with increasing amount of fertilizer Cu in the seed-soaking solution, and the magnitude of reduction in seed germination due to Cu toxicity increased with increasing duration of seed-soaking time in the Cu fertilizer solution. For the seed-soaked treatments, the detrimental effect of Cu on germination was greatest with 16 h soaking, where only 13% - 18% of the seeds germinated with Cu applied at 15 to 30 g Cu 100 kg-1 seed. For the 4 and 8 h seed soaking treatments, germination of wheat seed ranged from 73% to 83% with 15 g Cu 100 kg-1 seed treatment and 42% to 62% with 30 g Cu 100 kg-1 seed. The findings suggest that the detrimental effect of Cu on germination of wheat seed soaked in Cu EDTA solution can be decreased by reducing duration of soaking time from 16 h to 4 or 8 h, but this needs further investigation using soil under growth chamber and/or field conditions in order to make valid recommendations for use of this new technology on a commercial scale.展开更多
基金funded by the National Natural Science Foundation of China (Grant No. 51764014)the Natural Science Foundation of Jiangxi Province of China (Grant No. 20192BAB206018)+2 种基金the Education Commission of Jiangxi Province of China (GJJ160674)the Youth Jinggang Scholars Program in Jiangxi Provincethe Innovative Leading Talents Program in Ganzhou and Chongyi Zhangyuan Tungsten Co. Ltd., China, for the kind supports
文摘A clear understanding of the evolution characteristics of leaching solution’s damage to the basement rock of ion-adsorbed rare earth deposits is essential in the in situ leaching mining.In this study,some laboratory tests were carried out to investigate the deterioration behavior and failure mechanism of rock under the erosion of leaching solution.For this purpose,granite specimens were soaked in the leaching solution for different periods and then some physical and mechanical parameters were measured.The experimental results show that the strength of the rock without any soaking is the maximum.After 60 d,the rock strength,mass(dry)and P-wave velocity(dry)decrease to the minimum,while the porosity of the specimens reaches the maximum.Moreover,the failure pattern of the specimens in the uniaxial compression tests is affected as the soaking time increases.The scanning electron microscopy(SEM)image results indicate that the erosion of quartz crystals inside the rock specimens gets more intense with the increase of soaking time.Also,the internal crystal failure mode gradually changes from the trans-granular to the inter-granular.The insights gained from this study are helpful for better understanding the evolution characteristics of leaching solution’s damage to the basement rock of ionadsorbed rare earth deposits.
文摘A laboratory incubation experiment (20℃) was conducted to find if the detrimental effects of seed-soaked Cu on wheat seedlings can be minimized by reducing time duration of seed in contact with Cu EDTA fertilizer solution. The 24 treatments in a 6 x 4 factorial arrangement included 6 rates/amounts of Cu (0, 15, 30, 60, 120 and 240 g Cu 100 kg-1 seed) and 4 seed-soaking time durations (0, 4, 8 and 16 h). The germination of wheat seed was 100% in the zero-Cu control treatments, irrespective of the duration of seed soaking time. However, seed germination decreased with increasing amount of fertilizer Cu in the seed-soaking solution, and the magnitude of reduction in seed germination due to Cu toxicity increased with increasing duration of seed-soaking time in the Cu fertilizer solution. For the seed-soaked treatments, the detrimental effect of Cu on germination was greatest with 16 h soaking, where only 13% - 18% of the seeds germinated with Cu applied at 15 to 30 g Cu 100 kg-1 seed. For the 4 and 8 h seed soaking treatments, germination of wheat seed ranged from 73% to 83% with 15 g Cu 100 kg-1 seed treatment and 42% to 62% with 30 g Cu 100 kg-1 seed. The findings suggest that the detrimental effect of Cu on germination of wheat seed soaked in Cu EDTA solution can be decreased by reducing duration of soaking time from 16 h to 4 or 8 h, but this needs further investigation using soil under growth chamber and/or field conditions in order to make valid recommendations for use of this new technology on a commercial scale.
