微生物絮凝剂絮凝铝土矿和石英的比较研究

Comparison of Flocculation between Bauxite and Quartz by Bioflocculant

为考察微生物的代谢产物对矿物的作用，研究了放射形土壤杆菌产生的微生物絮凝剂对石英和铝土矿的絮凝作用。结果显示：在pH=3．0—7．0范围内，微生物絮凝剂能吸附于铝土矿表面而导致Zeta电位明显降低，铝土矿发生絮凝而加快沉降，pH=5．0时，2min内铝土矿的沉淀质量分数高达94．67％；而在整个pH=3．0—11．0的研究范围内，微生物絮凝剂对石英表面Zeta电位的影响都不大，絮凝剂分子难以吸附在石英颗粒表面而导致其絮凝，pH=5．0时，2min内石英的沉淀质量分数仅27．45％；另外，Ca^2＋对铝土矿有助凝作用而对石英影响很小。研究结果表明：所获微生物代谢产物可作为铝土矿的选择性絮凝剂。

To investigate the effect of the metabolite of microorganism on minerals, the flocculation of bauxite and quartz by the bioflocculant produced from radiate agrobacterium was studied. The results showed that within the pH range of 3.0 - 7.0, the bioflocculant readily adsorbed on the surface of bauxite, leading to a notable zeta potential decrease, flocculation and accelerated settling of the bauxite. At a pH = 5.0, the mass fraction of bauxite deposited reached as high as 94.67% within the first 2 minutes of precipitatation. While within the whole pH range of 3.0 - 11.0 that was investigated, the bioflocculant had little effect on the Zeta potential of quartz surface and hardly adsorbed on the quartz surface so as to make quartz flocculate. At a pH = 5.0, the mass fraction of quartz precipitated was only 27.45% within the first 2 minutes. Besides, Ca^2＋ could assist in the flocculation of bauxite but had little effect on quartz. The results showed that the acquired metabolite of microorganism can be used as selective flocculant for bauxite.