藻、有机质、粘土矿物富金成矿对比实验

Comparative Experiments on Gold Enrichment and Mineralization by Bacteria and Algae,organic material and clay minerals

藻、有机质、沉积物、粘土矿物富集和释放金的对比实验研究表明:活体生物富金能力较强,热水环境下温泉蓝细菌富金能力更强,并且为生物所富集的金易于迁出参与成矿;在生物生活的氧化环境,生物对金的作用主要表现为与生理活动有关的吸收作用,与金离子结合的生物配合物主要是含硫有机化合物;在沉积→成岩→成矿过程中,随着生物活体→死体→腐解有机质→有机淤泥→有机岩的变化,有机质对金的富集作用越来越小,并随着有机质成熟度的增加,其富金能力变弱而解析金的能力却增强。3种粘土矿物吸附金的能力为:伊利石>高岭石>蒙脱石,释放金的能力相反,并且粘土矿物的加入降低了有机质吸附和释放金的能力;油田卤水对富集于活体藻生物中的金的萃取能力强于无机流体。

Experimental studies of gold enrichment and releasing by bacteria, algae, organic matter, sediments and clay minerals show the following: ① the gold-enriching ability of living organism is stronger than dead ones,cyanobacteria in the hydrothermal environment have a stronger effect on gold enrichment than those living under the normal temperature conditions,and the gold enriched by organisms is easily released. ② In the oxidized environment in which organisms live, the gold-enriching mechanism of organisms is probably manifested by absorption relating to physiological action,and the most important ligand combined with gold is mainly sulfur-bearing organic compounds. ③ In the process of deposition → diagenesis → mineralizatio, the gold-enriching a-bility of organic matter becomes weaker with inreasing maturity of organic matter as there is a change of living organisms → dead organisms → decayed organic material → organic sludge → organic rock, but the gold-releasing ability is increased. ④ The gold-absorbing abilities of three types of clay minerals are illite >kaolinite>montmorillonite,but their gold-releasing abilities are on the contrary, and the gold-absorbing and -releasing abilities of organic matter decrease with the introduction of clay minerals. ⑤ Oil-field brine has a stronger ability extraction of gold-enriched by living algae than inorganic fluid.